From da6f343032cb01597dc7866e66f091adf3243a62 Mon Sep 17 00:00:00 2001 From: Michael Smith Date: Sat, 20 Nov 2021 03:10:50 +0000 Subject: Initial public snapshot With code from Bill. Thanks Bill! --- src/3p/chibicc/LICENSE | 21 + src/3p/chibicc/chibicc.h | 486 +++++++ src/3p/chibicc/codegen.c | 1595 ++++++++++++++++++++ src/3p/chibicc/hashmap.c | 165 +++ src/3p/chibicc/main.c | 791 ++++++++++ src/3p/chibicc/parse.c | 3368 +++++++++++++++++++++++++++++++++++++++++++ src/3p/chibicc/preprocess.c | 1208 ++++++++++++++++ src/3p/chibicc/strings.c | 17 + src/3p/chibicc/tokenize.c | 799 ++++++++++ src/3p/chibicc/type.c | 307 ++++ src/3p/chibicc/unicode.c | 189 +++ 11 files changed, 8946 insertions(+) create mode 100644 src/3p/chibicc/LICENSE create mode 100644 src/3p/chibicc/chibicc.h create mode 100644 src/3p/chibicc/codegen.c create mode 100644 src/3p/chibicc/hashmap.c create mode 100644 src/3p/chibicc/main.c create mode 100644 src/3p/chibicc/parse.c create mode 100644 src/3p/chibicc/preprocess.c create mode 100644 src/3p/chibicc/strings.c create mode 100644 src/3p/chibicc/tokenize.c create mode 100644 src/3p/chibicc/type.c create mode 100644 src/3p/chibicc/unicode.c (limited to 'src/3p/chibicc') diff --git a/src/3p/chibicc/LICENSE b/src/3p/chibicc/LICENSE new file mode 100644 index 0000000..2d1fd94 --- /dev/null +++ b/src/3p/chibicc/LICENSE @@ -0,0 +1,21 @@ +MIT License + +Copyright (c) 2019 Rui Ueyama + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/src/3p/chibicc/chibicc.h b/src/3p/chibicc/chibicc.h new file mode 100644 index 0000000..1719bc5 --- /dev/null +++ b/src/3p/chibicc/chibicc.h @@ -0,0 +1,486 @@ +// include guards: upstream doesn't have these but we add them so we can cat +// source files together (or #include them, in particular) +#ifndef INC_CHIBICC_H +#define INC_CHIBICC_H + +// note: removing defs/headers that aren't needed in tokenize.c and/or don't +// exist on Windows, in order to get our stuff working. total hack; oh well. +//#define _POSIX_C_SOURCE 200809L +#include +#include +#include +//#include +//#include +#include +#include +#include +#include +#include +// stdnoreturn means we can't use our noreturn (_Noreturn void) +// there are no noreturns in tokenize.c anyway, and the ones in this header have +// been changed to just _Noreturn to avoid any possible conflict +//#include +#include +//#include +#include +//#include +//#include +#include +//#include + +// exists on all Unixes but normally hidden _GNU_SOURCE on Linux. +// missing entirely on Windows (implemented in 3p/openbsd/asprintf.c for compat) +int vasprintf(char **str, const char *fmt, va_list ap); + +#define MAX(x, y) ((x) < (y) ? (y) : (x)) +#define MIN(x, y) ((x) < (y) ? (x) : (y)) + +#if !defined(__GNUC__) && !defined(__clang__) +# define __attribute__(x) +#endif + +typedef struct Type Type; +typedef struct Node Node; +typedef struct Member Member; +typedef struct Relocation Relocation; +typedef struct Hideset Hideset; + +// +// strings.c +// + +typedef struct { + char **data; + int capacity; + int len; +} StringArray; + +void strarray_push(StringArray *arr, char *s); + +// +// tokenize.c +// + +// Token +typedef enum { + TK_IDENT, // Identifiers + TK_PUNCT, // Punctuators + TK_KEYWORD, // Keywords + TK_STR, // String literals + TK_NUM, // Numeric literals + TK_PP_NUM, // Preprocessing numbers + TK_EOF, // End-of-file markers +} TokenKind; + +typedef struct { + char *name; + int file_no; + char *contents; + + // For #line directive + char *display_name; + int line_delta; +} File; + +// Token type +typedef struct Token Token; +struct Token { + TokenKind kind; // Token kind + Token *next; // Next token + int64_t val; // If kind is TK_NUM, its value + long double fval; // If kind is TK_NUM, its value + char *loc; // Token location + int len; // Token length + Type *ty; // Used if TK_NUM or TK_STR + char *str; // String literal contents including terminating '\0' + + File *file; // Source location + char *filename; // Filename + int line_no; // Line number + int line_delta; // Line number + bool at_bol; // True if this token is at beginning of line + bool has_space; // True if this token follows a space character + Hideset *hideset; // For macro expansion + Token *origin; // If this is expanded from a macro, the original token +}; + +_Noreturn void error(char *fmt, ...) __attribute__((format(printf, 1, 2))); +_Noreturn void error_at(char *loc, char *fmt, ...) __attribute__((format(printf, 2, 3))); +_Noreturn void error_tok(Token *tok, char *fmt, ...) __attribute__((format(printf, 2, 3))); +void warn_tok(Token *tok, char *fmt, ...) __attribute__((format(printf, 2, 3))); +bool equal(Token *tok, char *op); +Token *skip(Token *tok, char *op); +bool consume(Token **rest, Token *tok, char *str); +void convert_pp_tokens(Token *tok); +File **get_input_files(void); +File *new_file(char *name, int file_no, char *contents); +Token *tokenize_string_literal(Token *tok, Type *basety); +Token *tokenize(File *file); +//Token *tokenize_file(char *filename); +Token *tokenize_buf(const char *name, char *p); + +// note: replacing memstream-based format with asprintf version. moved down here +// as error() is declared above. +//char *format(char *fmt, ...) __attribute__((format(printf, 1, 2))); +__attribute__((format(printf, 1, 2))) +static inline char *format(const char *fmt, ...) { + char *ret; + va_list va; + va_start(va, fmt); + if (vasprintf(&ret, fmt, va) == -1) error("couldn't allocate memory"); + va_end(va); + return ret; +} + +#define unreachable() \ + error("internal error at %s:%d", __FILE__, __LINE__) + +// +// preprocess.c +// + +char *search_include_paths(char *filename); +void init_macros(void); +void define_macro(char *name, char *buf); +void undef_macro(char *name); +Token *preprocess(Token *tok); + +// +// parse.c +// + +// Variable or function +typedef struct Obj Obj; +struct Obj { + Obj *next; + char *name; // Variable name + Type *ty; // Type + Token *tok; // representative token + bool is_local; // local or global/function + int align; // alignment + + // Local variable + int offset; + + // Global variable or function + bool is_function; + bool is_definition; + bool is_static; + + // Global variable + bool is_tentative; + bool is_tls; + char *init_data; + Relocation *rel; + + // Function + bool is_inline; + Obj *params; + Node *body; + Obj *locals; + Obj *va_area; + Obj *alloca_bottom; + int stack_size; + + // Static inline function + bool is_live; + bool is_root; + StringArray refs; +}; + +// Global variable can be initialized either by a constant expression +// or a pointer to another global variable. This struct represents the +// latter. +typedef struct Relocation Relocation; +struct Relocation { + Relocation *next; + int offset; + char **label; + long addend; +}; + +// AST node +typedef enum { + ND_NULL_EXPR, // Do nothing + ND_ADD, // + + ND_SUB, // - + ND_MUL, // * + ND_DIV, // / + ND_NEG, // unary - + ND_MOD, // % + ND_BITAND, // & + ND_BITOR, // | + ND_BITXOR, // ^ + ND_SHL, // << + ND_SHR, // >> + ND_EQ, // == + ND_NE, // != + ND_LT, // < + ND_LE, // <= + ND_ASSIGN, // = + ND_COND, // ?: + ND_COMMA, // , + ND_MEMBER, // . (struct member access) + ND_ADDR, // unary & + ND_DEREF, // unary * + ND_NOT, // ! + ND_BITNOT, // ~ + ND_LOGAND, // && + ND_LOGOR, // || + ND_RETURN, // "return" + ND_IF, // "if" + ND_FOR, // "for" or "while" + ND_DO, // "do" + ND_SWITCH, // "switch" + ND_CASE, // "case" + ND_BLOCK, // { ... } + ND_GOTO, // "goto" + ND_GOTO_EXPR, // "goto" labels-as-values + ND_LABEL, // Labeled statement + ND_LABEL_VAL, // [GNU] Labels-as-values + ND_FUNCALL, // Function call + ND_EXPR_STMT, // Expression statement + ND_STMT_EXPR, // Statement expression + ND_VAR, // Variable + ND_VLA_PTR, // VLA designator + ND_NUM, // Integer + ND_CAST, // Type cast + ND_MEMZERO, // Zero-clear a stack variable + ND_ASM, // "asm" + ND_CAS, // Atomic compare-and-swap + ND_EXCH, // Atomic exchange +} NodeKind; + +// AST node type +struct Node { + NodeKind kind; // Node kind + Node *next; // Next node + Type *ty; // Type, e.g. int or pointer to int + Token *tok; // Representative token + + Node *lhs; // Left-hand side + Node *rhs; // Right-hand side + + // "if" or "for" statement + Node *cond; + Node *then; + Node *els; + Node *init; + Node *inc; + + // "break" and "continue" labels + char *brk_label; + char *cont_label; + + // Block or statement expression + Node *body; + + // Struct member access + Member *member; + + // Function call + Type *func_ty; + Node *args; + bool pass_by_stack; + Obj *ret_buffer; + + // Goto or labeled statement, or labels-as-values + char *label; + char *unique_label; + Node *goto_next; + + // Switch + Node *case_next; + Node *default_case; + + // Case + long begin; + long end; + + // "asm" string literal + char *asm_str; + + // Atomic compare-and-swap + Node *cas_addr; + Node *cas_old; + Node *cas_new; + + // Atomic op= operators + Obj *atomic_addr; + Node *atomic_expr; + + // Variable + Obj *var; + + // Numeric literal + int64_t val; + long double fval; +}; + +Node *new_cast(Node *expr, Type *ty); +int64_t const_expr(Token **rest, Token *tok); +Obj *parse(Token *tok); + +// +// type.c +// + +typedef enum { + TY_VOID, + TY_BOOL, + TY_CHAR, + TY_SHORT, + TY_INT, + TY_LONG, + TY_FLOAT, + TY_DOUBLE, + TY_LDOUBLE, + TY_ENUM, + TY_PTR, + TY_FUNC, + TY_ARRAY, + TY_VLA, // variable-length array + TY_STRUCT, + TY_UNION, +} TypeKind; + +struct Type { + TypeKind kind; + int size; // sizeof() value + int align; // alignment + bool is_unsigned; // unsigned or signed + bool is_atomic; // true if _Atomic + Type *origin; // for type compatibility check + + // Pointer-to or array-of type. We intentionally use the same member + // to represent pointer/array duality in C. + // + // In many contexts in which a pointer is expected, we examine this + // member instead of "kind" member to determine whether a type is a + // pointer or not. That means in many contexts "array of T" is + // naturally handled as if it were "pointer to T", as required by + // the C spec. + Type *base; + + // Declaration + Token *name; + Token *name_pos; + + // Array + int array_len; + + // Variable-length array + Node *vla_len; // # of elements + Obj *vla_size; // sizeof() value + + // Struct + Member *members; + bool is_flexible; + bool is_packed; + + // Function type + Type *return_ty; + Type *params; + bool is_variadic; + Type *next; +}; + +// Struct member +struct Member { + Member *next; + Type *ty; + Token *tok; // for error message + Token *name; + int idx; + int align; + int offset; + + // Bitfield + bool is_bitfield; + int bit_offset; + int bit_width; +}; + +extern Type *ty_void; +extern Type *ty_bool; + +extern Type *ty_char; +extern Type *ty_short; +extern Type *ty_int; +extern Type *ty_long; + +extern Type *ty_uchar; +extern Type *ty_ushort; +extern Type *ty_uint; +extern Type *ty_ulong; + +extern Type *ty_float; +extern Type *ty_double; +extern Type *ty_ldouble; + +bool is_integer(Type *ty); +bool is_flonum(Type *ty); +bool is_numeric(Type *ty); +bool is_compatible(Type *t1, Type *t2); +Type *copy_type(Type *ty); +Type *pointer_to(Type *base); +Type *func_type(Type *return_ty); +Type *array_of(Type *base, int size); +Type *vla_of(Type *base, Node *expr); +Type *enum_type(void); +Type *struct_type(void); +void add_type(Node *node); + +// +// codegen.c +// + +void codegen(Obj *prog, FILE *out); +int align_to(int n, int align); + +// +// unicode.c +// + +int encode_utf8(char *buf, uint32_t c); +uint32_t decode_utf8(char **new_pos, char *p); +bool is_ident1(uint32_t c); +bool is_ident2(uint32_t c); +int display_width(char *p, int len); + +// +// hashmap.c +// + +typedef struct { + char *key; + int keylen; + void *val; +} HashEntry; + +typedef struct { + HashEntry *buckets; + int capacity; + int used; +} HashMap; + +void *hashmap_get(HashMap *map, char *key); +void *hashmap_get2(HashMap *map, char *key, int keylen); +void hashmap_put(HashMap *map, char *key, void *val); +void hashmap_put2(HashMap *map, char *key, int keylen, void *val); +void hashmap_delete(HashMap *map, char *key); +void hashmap_delete2(HashMap *map, char *key, int keylen); +void hashmap_test(void); + +// +// main.c +// + +bool file_exists(char *path); + +extern StringArray include_paths; +extern bool opt_fpic; +extern bool opt_fcommon; +extern char *base_file; + +#endif diff --git a/src/3p/chibicc/codegen.c b/src/3p/chibicc/codegen.c new file mode 100644 index 0000000..da11fd7 --- /dev/null +++ b/src/3p/chibicc/codegen.c @@ -0,0 +1,1595 @@ +#include "chibicc.h" + +#define GP_MAX 6 +#define FP_MAX 8 + +static FILE *output_file; +static int depth; +static char *argreg8[] = {"%dil", "%sil", "%dl", "%cl", "%r8b", "%r9b"}; +static char *argreg16[] = {"%di", "%si", "%dx", "%cx", "%r8w", "%r9w"}; +static char *argreg32[] = {"%edi", "%esi", "%edx", "%ecx", "%r8d", "%r9d"}; +static char *argreg64[] = {"%rdi", "%rsi", "%rdx", "%rcx", "%r8", "%r9"}; +static Obj *current_fn; + +static void gen_expr(Node *node); +static void gen_stmt(Node *node); + +__attribute__((format(printf, 1, 2))) +static void println(char *fmt, ...) { + va_list ap; + va_start(ap, fmt); + vfprintf(output_file, fmt, ap); + va_end(ap); + fprintf(output_file, "\n"); +} + +static int count(void) { + static int i = 1; + return i++; +} + +static void push(void) { + println(" push %%rax"); + depth++; +} + +static void pop(char *arg) { + println(" pop %s", arg); + depth--; +} + +static void pushf(void) { + println(" sub $8, %%rsp"); + println(" movsd %%xmm0, (%%rsp)"); + depth++; +} + +static void popf(int reg) { + println(" movsd (%%rsp), %%xmm%d", reg); + println(" add $8, %%rsp"); + depth--; +} + +// Round up `n` to the nearest multiple of `align`. For instance, +// align_to(5, 8) returns 8 and align_to(11, 8) returns 16. +int align_to(int n, int align) { + return (n + align - 1) / align * align; +} + +static char *reg_dx(int sz) { + switch (sz) { + case 1: return "%dl"; + case 2: return "%dx"; + case 4: return "%edx"; + case 8: return "%rdx"; + } + unreachable(); +} + +static char *reg_ax(int sz) { + switch (sz) { + case 1: return "%al"; + case 2: return "%ax"; + case 4: return "%eax"; + case 8: return "%rax"; + } + unreachable(); +} + +// Compute the absolute address of a given node. +// It's an error if a given node does not reside in memory. +static void gen_addr(Node *node) { + switch (node->kind) { + case ND_VAR: + // Variable-length array, which is always local. + if (node->var->ty->kind == TY_VLA) { + println(" mov %d(%%rbp), %%rax", node->var->offset); + return; + } + + // Local variable + if (node->var->is_local) { + println(" lea %d(%%rbp), %%rax", node->var->offset); + return; + } + + if (opt_fpic) { + // Thread-local variable + if (node->var->is_tls) { + println(" data16 lea %s@tlsgd(%%rip), %%rdi", node->var->name); + println(" .value 0x6666"); + println(" rex64"); + println(" call __tls_get_addr@PLT"); + return; + } + + // Function or global variable + println(" mov %s@GOTPCREL(%%rip), %%rax", node->var->name); + return; + } + + // Thread-local variable + if (node->var->is_tls) { + println(" mov %%fs:0, %%rax"); + println(" add $%s@tpoff, %%rax", node->var->name); + return; + } + + // Here, we generate an absolute address of a function or a global + // variable. Even though they exist at a certain address at runtime, + // their addresses are not known at link-time for the following + // two reasons. + // + // - Address randomization: Executables are loaded to memory as a + // whole but it is not known what address they are loaded to. + // Therefore, at link-time, relative address in the same + // exectuable (i.e. the distance between two functions in the + // same executable) is known, but the absolute address is not + // known. + // + // - Dynamic linking: Dynamic shared objects (DSOs) or .so files + // are loaded to memory alongside an executable at runtime and + // linked by the runtime loader in memory. We know nothing + // about addresses of global stuff that may be defined by DSOs + // until the runtime relocation is complete. + // + // In order to deal with the former case, we use RIP-relative + // addressing, denoted by `(%rip)`. For the latter, we obtain an + // address of a stuff that may be in a shared object file from the + // Global Offset Table using `@GOTPCREL(%rip)` notation. + + // Function + if (node->ty->kind == TY_FUNC) { + if (node->var->is_definition) + println(" lea %s(%%rip), %%rax", node->var->name); + else + println(" mov %s@GOTPCREL(%%rip), %%rax", node->var->name); + return; + } + + // Global variable + println(" lea %s(%%rip), %%rax", node->var->name); + return; + case ND_DEREF: + gen_expr(node->lhs); + return; + case ND_COMMA: + gen_expr(node->lhs); + gen_addr(node->rhs); + return; + case ND_MEMBER: + gen_addr(node->lhs); + println(" add $%d, %%rax", node->member->offset); + return; + case ND_FUNCALL: + if (node->ret_buffer) { + gen_expr(node); + return; + } + break; + case ND_ASSIGN: + case ND_COND: + if (node->ty->kind == TY_STRUCT || node->ty->kind == TY_UNION) { + gen_expr(node); + return; + } + break; + case ND_VLA_PTR: + println(" lea %d(%%rbp), %%rax", node->var->offset); + return; + } + + error_tok(node->tok, "not an lvalue"); +} + +// Load a value from where %rax is pointing to. +static void load(Type *ty) { + switch (ty->kind) { + case TY_ARRAY: + case TY_STRUCT: + case TY_UNION: + case TY_FUNC: + case TY_VLA: + // If it is an array, do not attempt to load a value to the + // register because in general we can't load an entire array to a + // register. As a result, the result of an evaluation of an array + // becomes not the array itself but the address of the array. + // This is where "array is automatically converted to a pointer to + // the first element of the array in C" occurs. + return; + case TY_FLOAT: + println(" movss (%%rax), %%xmm0"); + return; + case TY_DOUBLE: + println(" movsd (%%rax), %%xmm0"); + return; + case TY_LDOUBLE: + println(" fldt (%%rax)"); + return; + } + + char *insn = ty->is_unsigned ? "movz" : "movs"; + + // When we load a char or a short value to a register, we always + // extend them to the size of int, so we can assume the lower half of + // a register always contains a valid value. The upper half of a + // register for char, short and int may contain garbage. When we load + // a long value to a register, it simply occupies the entire register. + if (ty->size == 1) + println(" %sbl (%%rax), %%eax", insn); + else if (ty->size == 2) + println(" %swl (%%rax), %%eax", insn); + else if (ty->size == 4) + println(" movsxd (%%rax), %%rax"); + else + println(" mov (%%rax), %%rax"); +} + +// Store %rax to an address that the stack top is pointing to. +static void store(Type *ty) { + pop("%rdi"); + + switch (ty->kind) { + case TY_STRUCT: + case TY_UNION: + for (int i = 0; i < ty->size; i++) { + println(" mov %d(%%rax), %%r8b", i); + println(" mov %%r8b, %d(%%rdi)", i); + } + return; + case TY_FLOAT: + println(" movss %%xmm0, (%%rdi)"); + return; + case TY_DOUBLE: + println(" movsd %%xmm0, (%%rdi)"); + return; + case TY_LDOUBLE: + println(" fstpt (%%rdi)"); + return; + } + + if (ty->size == 1) + println(" mov %%al, (%%rdi)"); + else if (ty->size == 2) + println(" mov %%ax, (%%rdi)"); + else if (ty->size == 4) + println(" mov %%eax, (%%rdi)"); + else + println(" mov %%rax, (%%rdi)"); +} + +static void cmp_zero(Type *ty) { + switch (ty->kind) { + case TY_FLOAT: + println(" xorps %%xmm1, %%xmm1"); + println(" ucomiss %%xmm1, %%xmm0"); + return; + case TY_DOUBLE: + println(" xorpd %%xmm1, %%xmm1"); + println(" ucomisd %%xmm1, %%xmm0"); + return; + case TY_LDOUBLE: + println(" fldz"); + println(" fucomip"); + println(" fstp %%st(0)"); + return; + } + + if (is_integer(ty) && ty->size <= 4) + println(" cmp $0, %%eax"); + else + println(" cmp $0, %%rax"); +} + +enum { I8, I16, I32, I64, U8, U16, U32, U64, F32, F64, F80 }; + +static int getTypeId(Type *ty) { + switch (ty->kind) { + case TY_CHAR: + return ty->is_unsigned ? U8 : I8; + case TY_SHORT: + return ty->is_unsigned ? U16 : I16; + case TY_INT: + return ty->is_unsigned ? U32 : I32; + case TY_LONG: + return ty->is_unsigned ? U64 : I64; + case TY_FLOAT: + return F32; + case TY_DOUBLE: + return F64; + case TY_LDOUBLE: + return F80; + } + return U64; +} + +// The table for type casts +static char i32i8[] = "movsbl %al, %eax"; +static char i32u8[] = "movzbl %al, %eax"; +static char i32i16[] = "movswl %ax, %eax"; +static char i32u16[] = "movzwl %ax, %eax"; +static char i32f32[] = "cvtsi2ssl %eax, %xmm0"; +static char i32i64[] = "movsxd %eax, %rax"; +static char i32f64[] = "cvtsi2sdl %eax, %xmm0"; +static char i32f80[] = "mov %eax, -4(%rsp); fildl -4(%rsp)"; + +static char u32f32[] = "mov %eax, %eax; cvtsi2ssq %rax, %xmm0"; +static char u32i64[] = "mov %eax, %eax"; +static char u32f64[] = "mov %eax, %eax; cvtsi2sdq %rax, %xmm0"; +static char u32f80[] = "mov %eax, %eax; mov %rax, -8(%rsp); fildll -8(%rsp)"; + +static char i64f32[] = "cvtsi2ssq %rax, %xmm0"; +static char i64f64[] = "cvtsi2sdq %rax, %xmm0"; +static char i64f80[] = "movq %rax, -8(%rsp); fildll -8(%rsp)"; + +static char u64f32[] = "cvtsi2ssq %rax, %xmm0"; +static char u64f64[] = + "test %rax,%rax; js 1f; pxor %xmm0,%xmm0; cvtsi2sd %rax,%xmm0; jmp 2f; " + "1: mov %rax,%rdi; and $1,%eax; pxor %xmm0,%xmm0; shr %rdi; " + "or %rax,%rdi; cvtsi2sd %rdi,%xmm0; addsd %xmm0,%xmm0; 2:"; +static char u64f80[] = + "mov %rax, -8(%rsp); fildq -8(%rsp); test %rax, %rax; jns 1f;" + "mov $1602224128, %eax; mov %eax, -4(%rsp); fadds -4(%rsp); 1:"; + +static char f32i8[] = "cvttss2sil %xmm0, %eax; movsbl %al, %eax"; +static char f32u8[] = "cvttss2sil %xmm0, %eax; movzbl %al, %eax"; +static char f32i16[] = "cvttss2sil %xmm0, %eax; movswl %ax, %eax"; +static char f32u16[] = "cvttss2sil %xmm0, %eax; movzwl %ax, %eax"; +static char f32i32[] = "cvttss2sil %xmm0, %eax"; +static char f32u32[] = "cvttss2siq %xmm0, %rax"; +static char f32i64[] = "cvttss2siq %xmm0, %rax"; +static char f32u64[] = "cvttss2siq %xmm0, %rax"; +static char f32f64[] = "cvtss2sd %xmm0, %xmm0"; +static char f32f80[] = "movss %xmm0, -4(%rsp); flds -4(%rsp)"; + +static char f64i8[] = "cvttsd2sil %xmm0, %eax; movsbl %al, %eax"; +static char f64u8[] = "cvttsd2sil %xmm0, %eax; movzbl %al, %eax"; +static char f64i16[] = "cvttsd2sil %xmm0, %eax; movswl %ax, %eax"; +static char f64u16[] = "cvttsd2sil %xmm0, %eax; movzwl %ax, %eax"; +static char f64i32[] = "cvttsd2sil %xmm0, %eax"; +static char f64u32[] = "cvttsd2siq %xmm0, %rax"; +static char f64i64[] = "cvttsd2siq %xmm0, %rax"; +static char f64u64[] = "cvttsd2siq %xmm0, %rax"; +static char f64f32[] = "cvtsd2ss %xmm0, %xmm0"; +static char f64f80[] = "movsd %xmm0, -8(%rsp); fldl -8(%rsp)"; + +#define FROM_F80_1 \ + "fnstcw -10(%rsp); movzwl -10(%rsp), %eax; or $12, %ah; " \ + "mov %ax, -12(%rsp); fldcw -12(%rsp); " + +#define FROM_F80_2 " -24(%rsp); fldcw -10(%rsp); " + +static char f80i8[] = FROM_F80_1 "fistps" FROM_F80_2 "movsbl -24(%rsp), %eax"; +static char f80u8[] = FROM_F80_1 "fistps" FROM_F80_2 "movzbl -24(%rsp), %eax"; +static char f80i16[] = FROM_F80_1 "fistps" FROM_F80_2 "movzbl -24(%rsp), %eax"; +static char f80u16[] = FROM_F80_1 "fistpl" FROM_F80_2 "movswl -24(%rsp), %eax"; +static char f80i32[] = FROM_F80_1 "fistpl" FROM_F80_2 "mov -24(%rsp), %eax"; +static char f80u32[] = FROM_F80_1 "fistpl" FROM_F80_2 "mov -24(%rsp), %eax"; +static char f80i64[] = FROM_F80_1 "fistpq" FROM_F80_2 "mov -24(%rsp), %rax"; +static char f80u64[] = FROM_F80_1 "fistpq" FROM_F80_2 "mov -24(%rsp), %rax"; +static char f80f32[] = "fstps -8(%rsp); movss -8(%rsp), %xmm0"; +static char f80f64[] = "fstpl -8(%rsp); movsd -8(%rsp), %xmm0"; + +static char *cast_table[][11] = { + // i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 f80 + {NULL, NULL, NULL, i32i64, i32u8, i32u16, NULL, i32i64, i32f32, i32f64, i32f80}, // i8 + {i32i8, NULL, NULL, i32i64, i32u8, i32u16, NULL, i32i64, i32f32, i32f64, i32f80}, // i16 + {i32i8, i32i16, NULL, i32i64, i32u8, i32u16, NULL, i32i64, i32f32, i32f64, i32f80}, // i32 + {i32i8, i32i16, NULL, NULL, i32u8, i32u16, NULL, NULL, i64f32, i64f64, i64f80}, // i64 + + {i32i8, NULL, NULL, i32i64, NULL, NULL, NULL, i32i64, i32f32, i32f64, i32f80}, // u8 + {i32i8, i32i16, NULL, i32i64, i32u8, NULL, NULL, i32i64, i32f32, i32f64, i32f80}, // u16 + {i32i8, i32i16, NULL, u32i64, i32u8, i32u16, NULL, u32i64, u32f32, u32f64, u32f80}, // u32 + {i32i8, i32i16, NULL, NULL, i32u8, i32u16, NULL, NULL, u64f32, u64f64, u64f80}, // u64 + + {f32i8, f32i16, f32i32, f32i64, f32u8, f32u16, f32u32, f32u64, NULL, f32f64, f32f80}, // f32 + {f64i8, f64i16, f64i32, f64i64, f64u8, f64u16, f64u32, f64u64, f64f32, NULL, f64f80}, // f64 + {f80i8, f80i16, f80i32, f80i64, f80u8, f80u16, f80u32, f80u64, f80f32, f80f64, NULL}, // f80 +}; + +static void cast(Type *from, Type *to) { + if (to->kind == TY_VOID) + return; + + if (to->kind == TY_BOOL) { + cmp_zero(from); + println(" setne %%al"); + println(" movzx %%al, %%eax"); + return; + } + + int t1 = getTypeId(from); + int t2 = getTypeId(to); + if (cast_table[t1][t2]) + println(" %s", cast_table[t1][t2]); +} + +// Structs or unions equal or smaller than 16 bytes are passed +// using up to two registers. +// +// If the first 8 bytes contains only floating-point type members, +// they are passed in an XMM register. Otherwise, they are passed +// in a general-purpose register. +// +// If a struct/union is larger than 8 bytes, the same rule is +// applied to the the next 8 byte chunk. +// +// This function returns true if `ty` has only floating-point +// members in its byte range [lo, hi). +static bool has_flonum(Type *ty, int lo, int hi, int offset) { + if (ty->kind == TY_STRUCT || ty->kind == TY_UNION) { + for (Member *mem = ty->members; mem; mem = mem->next) + if (!has_flonum(mem->ty, lo, hi, offset + mem->offset)) + return false; + return true; + } + + if (ty->kind == TY_ARRAY) { + for (int i = 0; i < ty->array_len; i++) + if (!has_flonum(ty->base, lo, hi, offset + ty->base->size * i)) + return false; + return true; + } + + return offset < lo || hi <= offset || ty->kind == TY_FLOAT || ty->kind == TY_DOUBLE; +} + +static bool has_flonum1(Type *ty) { + return has_flonum(ty, 0, 8, 0); +} + +static bool has_flonum2(Type *ty) { + return has_flonum(ty, 8, 16, 0); +} + +static void push_struct(Type *ty) { + int sz = align_to(ty->size, 8); + println(" sub $%d, %%rsp", sz); + depth += sz / 8; + + for (int i = 0; i < ty->size; i++) { + println(" mov %d(%%rax), %%r10b", i); + println(" mov %%r10b, %d(%%rsp)", i); + } +} + +static void push_args2(Node *args, bool first_pass) { + if (!args) + return; + push_args2(args->next, first_pass); + + if ((first_pass && !args->pass_by_stack) || (!first_pass && args->pass_by_stack)) + return; + + gen_expr(args); + + switch (args->ty->kind) { + case TY_STRUCT: + case TY_UNION: + push_struct(args->ty); + break; + case TY_FLOAT: + case TY_DOUBLE: + pushf(); + break; + case TY_LDOUBLE: + println(" sub $16, %%rsp"); + println(" fstpt (%%rsp)"); + depth += 2; + break; + default: + push(); + } +} + +// Load function call arguments. Arguments are already evaluated and +// stored to the stack as local variables. What we need to do in this +// function is to load them to registers or push them to the stack as +// specified by the x86-64 psABI. Here is what the spec says: +// +// - Up to 6 arguments of integral type are passed using RDI, RSI, +// RDX, RCX, R8 and R9. +// +// - Up to 8 arguments of floating-point type are passed using XMM0 to +// XMM7. +// +// - If all registers of an appropriate type are already used, push an +// argument to the stack in the right-to-left order. +// +// - Each argument passed on the stack takes 8 bytes, and the end of +// the argument area must be aligned to a 16 byte boundary. +// +// - If a function is variadic, set the number of floating-point type +// arguments to RAX. +static int push_args(Node *node) { + int stack = 0, gp = 0, fp = 0; + + // If the return type is a large struct/union, the caller passes + // a pointer to a buffer as if it were the first argument. + if (node->ret_buffer && node->ty->size > 16) + gp++; + + // Load as many arguments to the registers as possible. + for (Node *arg = node->args; arg; arg = arg->next) { + Type *ty = arg->ty; + + switch (ty->kind) { + case TY_STRUCT: + case TY_UNION: + if (ty->size > 16) { + arg->pass_by_stack = true; + stack += align_to(ty->size, 8) / 8; + } else { + bool fp1 = has_flonum1(ty); + bool fp2 = has_flonum2(ty); + + if (fp + fp1 + fp2 < FP_MAX && gp + !fp1 + !fp2 < GP_MAX) { + fp = fp + fp1 + fp2; + gp = gp + !fp1 + !fp2; + } else { + arg->pass_by_stack = true; + stack += align_to(ty->size, 8) / 8; + } + } + break; + case TY_FLOAT: + case TY_DOUBLE: + if (fp++ >= FP_MAX) { + arg->pass_by_stack = true; + stack++; + } + break; + case TY_LDOUBLE: + arg->pass_by_stack = true; + stack += 2; + break; + default: + if (gp++ >= GP_MAX) { + arg->pass_by_stack = true; + stack++; + } + } + } + + if ((depth + stack) % 2 == 1) { + println(" sub $8, %%rsp"); + depth++; + stack++; + } + + push_args2(node->args, true); + push_args2(node->args, false); + + // If the return type is a large struct/union, the caller passes + // a pointer to a buffer as if it were the first argument. + if (node->ret_buffer && node->ty->size > 16) { + println(" lea %d(%%rbp), %%rax", node->ret_buffer->offset); + push(); + } + + return stack; +} + +static void copy_ret_buffer(Obj *var) { + Type *ty = var->ty; + int gp = 0, fp = 0; + + if (has_flonum1(ty)) { + assert(ty->size == 4 || 8 <= ty->size); + if (ty->size == 4) + println(" movss %%xmm0, %d(%%rbp)", var->offset); + else + println(" movsd %%xmm0, %d(%%rbp)", var->offset); + fp++; + } else { + for (int i = 0; i < MIN(8, ty->size); i++) { + println(" mov %%al, %d(%%rbp)", var->offset + i); + println(" shr $8, %%rax"); + } + gp++; + } + + if (ty->size > 8) { + if (has_flonum2(ty)) { + assert(ty->size == 12 || ty->size == 16); + if (ty->size == 12) + println(" movss %%xmm%d, %d(%%rbp)", fp, var->offset + 8); + else + println(" movsd %%xmm%d, %d(%%rbp)", fp, var->offset + 8); + } else { + char *reg1 = (gp == 0) ? "%al" : "%dl"; + char *reg2 = (gp == 0) ? "%rax" : "%rdx"; + for (int i = 8; i < MIN(16, ty->size); i++) { + println(" mov %s, %d(%%rbp)", reg1, var->offset + i); + println(" shr $8, %s", reg2); + } + } + } +} + +static void copy_struct_reg(void) { + Type *ty = current_fn->ty->return_ty; + int gp = 0, fp = 0; + + println(" mov %%rax, %%rdi"); + + if (has_flonum(ty, 0, 8, 0)) { + assert(ty->size == 4 || 8 <= ty->size); + if (ty->size == 4) + println(" movss (%%rdi), %%xmm0"); + else + println(" movsd (%%rdi), %%xmm0"); + fp++; + } else { + println(" mov $0, %%rax"); + for (int i = MIN(8, ty->size) - 1; i >= 0; i--) { + println(" shl $8, %%rax"); + println(" mov %d(%%rdi), %%al", i); + } + gp++; + } + + if (ty->size > 8) { + if (has_flonum(ty, 8, 16, 0)) { + assert(ty->size == 12 || ty->size == 16); + if (ty->size == 4) + println(" movss 8(%%rdi), %%xmm%d", fp); + else + println(" movsd 8(%%rdi), %%xmm%d", fp); + } else { + char *reg1 = (gp == 0) ? "%al" : "%dl"; + char *reg2 = (gp == 0) ? "%rax" : "%rdx"; + println(" mov $0, %s", reg2); + for (int i = MIN(16, ty->size) - 1; i >= 8; i--) { + println(" shl $8, %s", reg2); + println(" mov %d(%%rdi), %s", i, reg1); + } + } + } +} + +static void copy_struct_mem(void) { + Type *ty = current_fn->ty->return_ty; + Obj *var = current_fn->params; + + println(" mov %d(%%rbp), %%rdi", var->offset); + + for (int i = 0; i < ty->size; i++) { + println(" mov %d(%%rax), %%dl", i); + println(" mov %%dl, %d(%%rdi)", i); + } +} + +static void builtin_alloca(void) { + // Align size to 16 bytes. + println(" add $15, %%rdi"); + println(" and $0xfffffff0, %%edi"); + + // Shift the temporary area by %rdi. + println(" mov %d(%%rbp), %%rcx", current_fn->alloca_bottom->offset); + println(" sub %%rsp, %%rcx"); + println(" mov %%rsp, %%rax"); + println(" sub %%rdi, %%rsp"); + println(" mov %%rsp, %%rdx"); + println("1:"); + println(" cmp $0, %%rcx"); + println(" je 2f"); + println(" mov (%%rax), %%r8b"); + println(" mov %%r8b, (%%rdx)"); + println(" inc %%rdx"); + println(" inc %%rax"); + println(" dec %%rcx"); + println(" jmp 1b"); + println("2:"); + + // Move alloca_bottom pointer. + println(" mov %d(%%rbp), %%rax", current_fn->alloca_bottom->offset); + println(" sub %%rdi, %%rax"); + println(" mov %%rax, %d(%%rbp)", current_fn->alloca_bottom->offset); +} + +// Generate code for a given node. +static void gen_expr(Node *node) { + println(" .loc %d %d", node->tok->file->file_no, node->tok->line_no); + + switch (node->kind) { + case ND_NULL_EXPR: + return; + case ND_NUM: { + switch (node->ty->kind) { + case TY_FLOAT: { + union { float f32; uint32_t u32; } u = { node->fval }; + println(" mov $%u, %%eax # float %Lf", u.u32, node->fval); + println(" movq %%rax, %%xmm0"); + return; + } + case TY_DOUBLE: { + union { double f64; uint64_t u64; } u = { node->fval }; + println(" mov $%lu, %%rax # double %Lf", u.u64, node->fval); + println(" movq %%rax, %%xmm0"); + return; + } + case TY_LDOUBLE: { + union { long double f80; uint64_t u64[2]; } u; + memset(&u, 0, sizeof(u)); + u.f80 = node->fval; + println(" mov $%lu, %%rax # long double %Lf", u.u64[0], node->fval); + println(" mov %%rax, -16(%%rsp)"); + println(" mov $%lu, %%rax", u.u64[1]); + println(" mov %%rax, -8(%%rsp)"); + println(" fldt -16(%%rsp)"); + return; + } + } + + println(" mov $%ld, %%rax", node->val); + return; + } + case ND_NEG: + gen_expr(node->lhs); + + switch (node->ty->kind) { + case TY_FLOAT: + println(" mov $1, %%rax"); + println(" shl $31, %%rax"); + println(" movq %%rax, %%xmm1"); + println(" xorps %%xmm1, %%xmm0"); + return; + case TY_DOUBLE: + println(" mov $1, %%rax"); + println(" shl $63, %%rax"); + println(" movq %%rax, %%xmm1"); + println(" xorpd %%xmm1, %%xmm0"); + return; + case TY_LDOUBLE: + println(" fchs"); + return; + } + + println(" neg %%rax"); + return; + case ND_VAR: + gen_addr(node); + load(node->ty); + return; + case ND_MEMBER: { + gen_addr(node); + load(node->ty); + + Member *mem = node->member; + if (mem->is_bitfield) { + println(" shl $%d, %%rax", 64 - mem->bit_width - mem->bit_offset); + if (mem->ty->is_unsigned) + println(" shr $%d, %%rax", 64 - mem->bit_width); + else + println(" sar $%d, %%rax", 64 - mem->bit_width); + } + return; + } + case ND_DEREF: + gen_expr(node->lhs); + load(node->ty); + return; + case ND_ADDR: + gen_addr(node->lhs); + return; + case ND_ASSIGN: + gen_addr(node->lhs); + push(); + gen_expr(node->rhs); + + if (node->lhs->kind == ND_MEMBER && node->lhs->member->is_bitfield) { + println(" mov %%rax, %%r8"); + + // If the lhs is a bitfield, we need to read the current value + // from memory and merge it with a new value. + Member *mem = node->lhs->member; + println(" mov %%rax, %%rdi"); + println(" and $%ld, %%rdi", (1L << mem->bit_width) - 1); + println(" shl $%d, %%rdi", mem->bit_offset); + + println(" mov (%%rsp), %%rax"); + load(mem->ty); + + long mask = ((1L << mem->bit_width) - 1) << mem->bit_offset; + println(" mov $%ld, %%r9", ~mask); + println(" and %%r9, %%rax"); + println(" or %%rdi, %%rax"); + store(node->ty); + println(" mov %%r8, %%rax"); + return; + } + + store(node->ty); + return; + case ND_STMT_EXPR: + for (Node *n = node->body; n; n = n->next) + gen_stmt(n); + return; + case ND_COMMA: + gen_expr(node->lhs); + gen_expr(node->rhs); + return; + case ND_CAST: + gen_expr(node->lhs); + cast(node->lhs->ty, node->ty); + return; + case ND_MEMZERO: + // `rep stosb` is equivalent to `memset(%rdi, %al, %rcx)`. + println(" mov $%d, %%rcx", node->var->ty->size); + println(" lea %d(%%rbp), %%rdi", node->var->offset); + println(" mov $0, %%al"); + println(" rep stosb"); + return; + case ND_COND: { + int c = count(); + gen_expr(node->cond); + cmp_zero(node->cond->ty); + println(" je .L.else.%d", c); + gen_expr(node->then); + println(" jmp .L.end.%d", c); + println(".L.else.%d:", c); + gen_expr(node->els); + println(".L.end.%d:", c); + return; + } + case ND_NOT: + gen_expr(node->lhs); + cmp_zero(node->lhs->ty); + println(" sete %%al"); + println(" movzx %%al, %%rax"); + return; + case ND_BITNOT: + gen_expr(node->lhs); + println(" not %%rax"); + return; + case ND_LOGAND: { + int c = count(); + gen_expr(node->lhs); + cmp_zero(node->lhs->ty); + println(" je .L.false.%d", c); + gen_expr(node->rhs); + cmp_zero(node->rhs->ty); + println(" je .L.false.%d", c); + println(" mov $1, %%rax"); + println(" jmp .L.end.%d", c); + println(".L.false.%d:", c); + println(" mov $0, %%rax"); + println(".L.end.%d:", c); + return; + } + case ND_LOGOR: { + int c = count(); + gen_expr(node->lhs); + cmp_zero(node->lhs->ty); + println(" jne .L.true.%d", c); + gen_expr(node->rhs); + cmp_zero(node->rhs->ty); + println(" jne .L.true.%d", c); + println(" mov $0, %%rax"); + println(" jmp .L.end.%d", c); + println(".L.true.%d:", c); + println(" mov $1, %%rax"); + println(".L.end.%d:", c); + return; + } + case ND_FUNCALL: { + if (node->lhs->kind == ND_VAR && !strcmp(node->lhs->var->name, "alloca")) { + gen_expr(node->args); + println(" mov %%rax, %%rdi"); + builtin_alloca(); + return; + } + + int stack_args = push_args(node); + gen_expr(node->lhs); + + int gp = 0, fp = 0; + + // If the return type is a large struct/union, the caller passes + // a pointer to a buffer as if it were the first argument. + if (node->ret_buffer && node->ty->size > 16) + pop(argreg64[gp++]); + + for (Node *arg = node->args; arg; arg = arg->next) { + Type *ty = arg->ty; + + switch (ty->kind) { + case TY_STRUCT: + case TY_UNION: + if (ty->size > 16) + continue; + + bool fp1 = has_flonum1(ty); + bool fp2 = has_flonum2(ty); + + if (fp + fp1 + fp2 < FP_MAX && gp + !fp1 + !fp2 < GP_MAX) { + if (fp1) + popf(fp++); + else + pop(argreg64[gp++]); + + if (ty->size > 8) { + if (fp2) + popf(fp++); + else + pop(argreg64[gp++]); + } + } + break; + case TY_FLOAT: + case TY_DOUBLE: + if (fp < FP_MAX) + popf(fp++); + break; + case TY_LDOUBLE: + break; + default: + if (gp < GP_MAX) + pop(argreg64[gp++]); + } + } + + println(" mov %%rax, %%r10"); + println(" mov $%d, %%rax", fp); + println(" call *%%r10"); + println(" add $%d, %%rsp", stack_args * 8); + + depth -= stack_args; + + // It looks like the most significant 48 or 56 bits in RAX may + // contain garbage if a function return type is short or bool/char, + // respectively. We clear the upper bits here. + switch (node->ty->kind) { + case TY_BOOL: + println(" movzx %%al, %%eax"); + return; + case TY_CHAR: + if (node->ty->is_unsigned) + println(" movzbl %%al, %%eax"); + else + println(" movsbl %%al, %%eax"); + return; + case TY_SHORT: + if (node->ty->is_unsigned) + println(" movzwl %%ax, %%eax"); + else + println(" movswl %%ax, %%eax"); + return; + } + + // If the return type is a small struct, a value is returned + // using up to two registers. + if (node->ret_buffer && node->ty->size <= 16) { + copy_ret_buffer(node->ret_buffer); + println(" lea %d(%%rbp), %%rax", node->ret_buffer->offset); + } + + return; + } + case ND_LABEL_VAL: + println(" lea %s(%%rip), %%rax", node->unique_label); + return; + case ND_CAS: { + gen_expr(node->cas_addr); + push(); + gen_expr(node->cas_new); + push(); + gen_expr(node->cas_old); + println(" mov %%rax, %%r8"); + load(node->cas_old->ty->base); + pop("%rdx"); // new + pop("%rdi"); // addr + + int sz = node->cas_addr->ty->base->size; + println(" lock cmpxchg %s, (%%rdi)", reg_dx(sz)); + println(" sete %%cl"); + println(" je 1f"); + println(" mov %s, (%%r8)", reg_ax(sz)); + println("1:"); + println(" movzbl %%cl, %%eax"); + return; + } + case ND_EXCH: { + gen_expr(node->lhs); + push(); + gen_expr(node->rhs); + pop("%rdi"); + + int sz = node->lhs->ty->base->size; + println(" xchg %s, (%%rdi)", reg_ax(sz)); + return; + } + } + + switch (node->lhs->ty->kind) { + case TY_FLOAT: + case TY_DOUBLE: { + gen_expr(node->rhs); + pushf(); + gen_expr(node->lhs); + popf(1); + + char *sz = (node->lhs->ty->kind == TY_FLOAT) ? "ss" : "sd"; + + switch (node->kind) { + case ND_ADD: + println(" add%s %%xmm1, %%xmm0", sz); + return; + case ND_SUB: + println(" sub%s %%xmm1, %%xmm0", sz); + return; + case ND_MUL: + println(" mul%s %%xmm1, %%xmm0", sz); + return; + case ND_DIV: + println(" div%s %%xmm1, %%xmm0", sz); + return; + case ND_EQ: + case ND_NE: + case ND_LT: + case ND_LE: + println(" ucomi%s %%xmm0, %%xmm1", sz); + + if (node->kind == ND_EQ) { + println(" sete %%al"); + println(" setnp %%dl"); + println(" and %%dl, %%al"); + } else if (node->kind == ND_NE) { + println(" setne %%al"); + println(" setp %%dl"); + println(" or %%dl, %%al"); + } else if (node->kind == ND_LT) { + println(" seta %%al"); + } else { + println(" setae %%al"); + } + + println(" and $1, %%al"); + println(" movzb %%al, %%rax"); + return; + } + + error_tok(node->tok, "invalid expression"); + } + case TY_LDOUBLE: { + gen_expr(node->lhs); + gen_expr(node->rhs); + + switch (node->kind) { + case ND_ADD: + println(" faddp"); + return; + case ND_SUB: + println(" fsubrp"); + return; + case ND_MUL: + println(" fmulp"); + return; + case ND_DIV: + println(" fdivrp"); + return; + case ND_EQ: + case ND_NE: + case ND_LT: + case ND_LE: + println(" fcomip"); + println(" fstp %%st(0)"); + + if (node->kind == ND_EQ) + println(" sete %%al"); + else if (node->kind == ND_NE) + println(" setne %%al"); + else if (node->kind == ND_LT) + println(" seta %%al"); + else + println(" setae %%al"); + + println(" movzb %%al, %%rax"); + return; + } + + error_tok(node->tok, "invalid expression"); + } + } + + gen_expr(node->rhs); + push(); + gen_expr(node->lhs); + pop("%rdi"); + + char *ax, *di, *dx; + + if (node->lhs->ty->kind == TY_LONG || node->lhs->ty->base) { + ax = "%rax"; + di = "%rdi"; + dx = "%rdx"; + } else { + ax = "%eax"; + di = "%edi"; + dx = "%edx"; + } + + switch (node->kind) { + case ND_ADD: + println(" add %s, %s", di, ax); + return; + case ND_SUB: + println(" sub %s, %s", di, ax); + return; + case ND_MUL: + println(" imul %s, %s", di, ax); + return; + case ND_DIV: + case ND_MOD: + if (node->ty->is_unsigned) { + println(" mov $0, %s", dx); + println(" div %s", di); + } else { + if (node->lhs->ty->size == 8) + println(" cqo"); + else + println(" cdq"); + println(" idiv %s", di); + } + + if (node->kind == ND_MOD) + println(" mov %%rdx, %%rax"); + return; + case ND_BITAND: + println(" and %s, %s", di, ax); + return; + case ND_BITOR: + println(" or %s, %s", di, ax); + return; + case ND_BITXOR: + println(" xor %s, %s", di, ax); + return; + case ND_EQ: + case ND_NE: + case ND_LT: + case ND_LE: + println(" cmp %s, %s", di, ax); + + if (node->kind == ND_EQ) { + println(" sete %%al"); + } else if (node->kind == ND_NE) { + println(" setne %%al"); + } else if (node->kind == ND_LT) { + if (node->lhs->ty->is_unsigned) + println(" setb %%al"); + else + println(" setl %%al"); + } else if (node->kind == ND_LE) { + if (node->lhs->ty->is_unsigned) + println(" setbe %%al"); + else + println(" setle %%al"); + } + + println(" movzb %%al, %%rax"); + return; + case ND_SHL: + println(" mov %%rdi, %%rcx"); + println(" shl %%cl, %s", ax); + return; + case ND_SHR: + println(" mov %%rdi, %%rcx"); + if (node->lhs->ty->is_unsigned) + println(" shr %%cl, %s", ax); + else + println(" sar %%cl, %s", ax); + return; + } + + error_tok(node->tok, "invalid expression"); +} + +static void gen_stmt(Node *node) { + println(" .loc %d %d", node->tok->file->file_no, node->tok->line_no); + + switch (node->kind) { + case ND_IF: { + int c = count(); + gen_expr(node->cond); + cmp_zero(node->cond->ty); + println(" je .L.else.%d", c); + gen_stmt(node->then); + println(" jmp .L.end.%d", c); + println(".L.else.%d:", c); + if (node->els) + gen_stmt(node->els); + println(".L.end.%d:", c); + return; + } + case ND_FOR: { + int c = count(); + if (node->init) + gen_stmt(node->init); + println(".L.begin.%d:", c); + if (node->cond) { + gen_expr(node->cond); + cmp_zero(node->cond->ty); + println(" je %s", node->brk_label); + } + gen_stmt(node->then); + println("%s:", node->cont_label); + if (node->inc) + gen_expr(node->inc); + println(" jmp .L.begin.%d", c); + println("%s:", node->brk_label); + return; + } + case ND_DO: { + int c = count(); + println(".L.begin.%d:", c); + gen_stmt(node->then); + println("%s:", node->cont_label); + gen_expr(node->cond); + cmp_zero(node->cond->ty); + println(" jne .L.begin.%d", c); + println("%s:", node->brk_label); + return; + } + case ND_SWITCH: + gen_expr(node->cond); + + for (Node *n = node->case_next; n; n = n->case_next) { + char *ax = (node->cond->ty->size == 8) ? "%rax" : "%eax"; + char *di = (node->cond->ty->size == 8) ? "%rdi" : "%edi"; + + if (n->begin == n->end) { + println(" cmp $%ld, %s", n->begin, ax); + println(" je %s", n->label); + continue; + } + + // [GNU] Case ranges + println(" mov %s, %s", ax, di); + println(" sub $%ld, %s", n->begin, di); + println(" cmp $%ld, %s", n->end - n->begin, di); + println(" jbe %s", n->label); + } + + if (node->default_case) + println(" jmp %s", node->default_case->label); + + println(" jmp %s", node->brk_label); + gen_stmt(node->then); + println("%s:", node->brk_label); + return; + case ND_CASE: + println("%s:", node->label); + gen_stmt(node->lhs); + return; + case ND_BLOCK: + for (Node *n = node->body; n; n = n->next) + gen_stmt(n); + return; + case ND_GOTO: + println(" jmp %s", node->unique_label); + return; + case ND_GOTO_EXPR: + gen_expr(node->lhs); + println(" jmp *%%rax"); + return; + case ND_LABEL: + println("%s:", node->unique_label); + gen_stmt(node->lhs); + return; + case ND_RETURN: + if (node->lhs) { + gen_expr(node->lhs); + Type *ty = node->lhs->ty; + + switch (ty->kind) { + case TY_STRUCT: + case TY_UNION: + if (ty->size <= 16) + copy_struct_reg(); + else + copy_struct_mem(); + break; + } + } + + println(" jmp .L.return.%s", current_fn->name); + return; + case ND_EXPR_STMT: + gen_expr(node->lhs); + return; + case ND_ASM: + println(" %s", node->asm_str); + return; + } + + error_tok(node->tok, "invalid statement"); +} + +// Assign offsets to local variables. +static void assign_lvar_offsets(Obj *prog) { + for (Obj *fn = prog; fn; fn = fn->next) { + if (!fn->is_function) + continue; + + // If a function has many parameters, some parameters are + // inevitably passed by stack rather than by register. + // The first passed-by-stack parameter resides at RBP+16. + int top = 16; + int bottom = 0; + + int gp = 0, fp = 0; + + // Assign offsets to pass-by-stack parameters. + for (Obj *var = fn->params; var; var = var->next) { + Type *ty = var->ty; + + switch (ty->kind) { + case TY_STRUCT: + case TY_UNION: + if (ty->size <= 16) { + bool fp1 = has_flonum(ty, 0, 8, 0); + bool fp2 = has_flonum(ty, 8, 16, 8); + if (fp + fp1 + fp2 < FP_MAX && gp + !fp1 + !fp2 < GP_MAX) { + fp = fp + fp1 + fp2; + gp = gp + !fp1 + !fp2; + continue; + } + } + break; + case TY_FLOAT: + case TY_DOUBLE: + if (fp++ < FP_MAX) + continue; + break; + case TY_LDOUBLE: + break; + default: + if (gp++ < GP_MAX) + continue; + } + + top = align_to(top, 8); + var->offset = top; + top += var->ty->size; + } + + // Assign offsets to pass-by-register parameters and local variables. + for (Obj *var = fn->locals; var; var = var->next) { + if (var->offset) + continue; + + // AMD64 System V ABI has a special alignment rule for an array of + // length at least 16 bytes. We need to align such array to at least + // 16-byte boundaries. See p.14 of + // https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-draft.pdf. + int align = (var->ty->kind == TY_ARRAY && var->ty->size >= 16) + ? MAX(16, var->align) : var->align; + + bottom += var->ty->size; + bottom = align_to(bottom, align); + var->offset = -bottom; + } + + fn->stack_size = align_to(bottom, 16); + } +} + +static void emit_data(Obj *prog) { + for (Obj *var = prog; var; var = var->next) { + if (var->is_function || !var->is_definition) + continue; + + if (var->is_static) + println(" .local %s", var->name); + else + println(" .globl %s", var->name); + + int align = (var->ty->kind == TY_ARRAY && var->ty->size >= 16) + ? MAX(16, var->align) : var->align; + + // Common symbol + if (opt_fcommon && var->is_tentative) { + println(" .comm %s, %d, %d", var->name, var->ty->size, align); + continue; + } + + // .data or .tdata + if (var->init_data) { + if (var->is_tls) + println(" .section .tdata,\"awT\",@progbits"); + else + println(" .data"); + + println(" .type %s, @object", var->name); + println(" .size %s, %d", var->name, var->ty->size); + println(" .align %d", align); + println("%s:", var->name); + + Relocation *rel = var->rel; + int pos = 0; + while (pos < var->ty->size) { + if (rel && rel->offset == pos) { + println(" .quad %s%+ld", *rel->label, rel->addend); + rel = rel->next; + pos += 8; + } else { + println(" .byte %d", var->init_data[pos++]); + } + } + continue; + } + + // .bss or .tbss + if (var->is_tls) + println(" .section .tbss,\"awT\",@nobits"); + else + println(" .bss"); + + println(" .align %d", align); + println("%s:", var->name); + println(" .zero %d", var->ty->size); + } +} + +static void store_fp(int r, int offset, int sz) { + switch (sz) { + case 4: + println(" movss %%xmm%d, %d(%%rbp)", r, offset); + return; + case 8: + println(" movsd %%xmm%d, %d(%%rbp)", r, offset); + return; + } + unreachable(); +} + +static void store_gp(int r, int offset, int sz) { + switch (sz) { + case 1: + println(" mov %s, %d(%%rbp)", argreg8[r], offset); + return; + case 2: + println(" mov %s, %d(%%rbp)", argreg16[r], offset); + return; + case 4: + println(" mov %s, %d(%%rbp)", argreg32[r], offset); + return; + case 8: + println(" mov %s, %d(%%rbp)", argreg64[r], offset); + return; + default: + for (int i = 0; i < sz; i++) { + println(" mov %s, %d(%%rbp)", argreg8[r], offset + i); + println(" shr $8, %s", argreg64[r]); + } + return; + } +} + +static void emit_text(Obj *prog) { + for (Obj *fn = prog; fn; fn = fn->next) { + if (!fn->is_function || !fn->is_definition) + continue; + + // No code is emitted for "static inline" functions + // if no one is referencing them. + if (!fn->is_live) + continue; + + if (fn->is_static) + println(" .local %s", fn->name); + else + println(" .globl %s", fn->name); + + println(" .text"); + println(" .type %s, @function", fn->name); + println("%s:", fn->name); + current_fn = fn; + + // Prologue + println(" push %%rbp"); + println(" mov %%rsp, %%rbp"); + println(" sub $%d, %%rsp", fn->stack_size); + println(" mov %%rsp, %d(%%rbp)", fn->alloca_bottom->offset); + + // Save arg registers if function is variadic + if (fn->va_area) { + int gp = 0, fp = 0; + for (Obj *var = fn->params; var; var = var->next) { + if (is_flonum(var->ty)) + fp++; + else + gp++; + } + + int off = fn->va_area->offset; + + // va_elem + println(" movl $%d, %d(%%rbp)", gp * 8, off); // gp_offset + println(" movl $%d, %d(%%rbp)", fp * 8 + 48, off + 4); // fp_offset + println(" movq %%rbp, %d(%%rbp)", off + 8); // overflow_arg_area + println(" addq $16, %d(%%rbp)", off + 8); + println(" movq %%rbp, %d(%%rbp)", off + 16); // reg_save_area + println(" addq $%d, %d(%%rbp)", off + 24, off + 16); + + // __reg_save_area__ + println(" movq %%rdi, %d(%%rbp)", off + 24); + println(" movq %%rsi, %d(%%rbp)", off + 32); + println(" movq %%rdx, %d(%%rbp)", off + 40); + println(" movq %%rcx, %d(%%rbp)", off + 48); + println(" movq %%r8, %d(%%rbp)", off + 56); + println(" movq %%r9, %d(%%rbp)", off + 64); + println(" movsd %%xmm0, %d(%%rbp)", off + 72); + println(" movsd %%xmm1, %d(%%rbp)", off + 80); + println(" movsd %%xmm2, %d(%%rbp)", off + 88); + println(" movsd %%xmm3, %d(%%rbp)", off + 96); + println(" movsd %%xmm4, %d(%%rbp)", off + 104); + println(" movsd %%xmm5, %d(%%rbp)", off + 112); + println(" movsd %%xmm6, %d(%%rbp)", off + 120); + println(" movsd %%xmm7, %d(%%rbp)", off + 128); + } + + // Save passed-by-register arguments to the stack + int gp = 0, fp = 0; + for (Obj *var = fn->params; var; var = var->next) { + if (var->offset > 0) + continue; + + Type *ty = var->ty; + + switch (ty->kind) { + case TY_STRUCT: + case TY_UNION: + assert(ty->size <= 16); + if (has_flonum(ty, 0, 8, 0)) + store_fp(fp++, var->offset, MIN(8, ty->size)); + else + store_gp(gp++, var->offset, MIN(8, ty->size)); + + if (ty->size > 8) { + if (has_flonum(ty, 8, 16, 0)) + store_fp(fp++, var->offset + 8, ty->size - 8); + else + store_gp(gp++, var->offset + 8, ty->size - 8); + } + break; + case TY_FLOAT: + case TY_DOUBLE: + store_fp(fp++, var->offset, ty->size); + break; + default: + store_gp(gp++, var->offset, ty->size); + } + } + + // Emit code + gen_stmt(fn->body); + assert(depth == 0); + + // [https://www.sigbus.info/n1570#5.1.2.2.3p1] The C spec defines + // a special rule for the main function. Reaching the end of the + // main function is equivalent to returning 0, even though the + // behavior is undefined for the other functions. + if (strcmp(fn->name, "main") == 0) + println(" mov $0, %%rax"); + + // Epilogue + println(".L.return.%s:", fn->name); + println(" mov %%rbp, %%rsp"); + println(" pop %%rbp"); + println(" ret"); + } +} + +void codegen(Obj *prog, FILE *out) { + output_file = out; + + File **files = get_input_files(); + for (int i = 0; files[i]; i++) + println(" .file %d \"%s\"", files[i]->file_no, files[i]->name); + + assign_lvar_offsets(prog); + emit_data(prog); + emit_text(prog); +} diff --git a/src/3p/chibicc/hashmap.c b/src/3p/chibicc/hashmap.c new file mode 100644 index 0000000..46539d9 --- /dev/null +++ b/src/3p/chibicc/hashmap.c @@ -0,0 +1,165 @@ +// This is an implementation of the open-addressing hash table. + +#include "chibicc.h" + +// Initial hash bucket size +#define INIT_SIZE 16 + +// Rehash if the usage exceeds 70%. +#define HIGH_WATERMARK 70 + +// We'll keep the usage below 50% after rehashing. +#define LOW_WATERMARK 50 + +// Represents a deleted hash entry +#define TOMBSTONE ((void *)-1) + +static uint64_t fnv_hash(char *s, int len) { + uint64_t hash = 0xcbf29ce484222325; + for (int i = 0; i < len; i++) { + hash *= 0x100000001b3; + hash ^= (unsigned char)s[i]; + } + return hash; +} + +// Make room for new entires in a given hashmap by removing +// tombstones and possibly extending the bucket size. +static void rehash(HashMap *map) { + // Compute the size of the new hashmap. + int nkeys = 0; + for (int i = 0; i < map->capacity; i++) + if (map->buckets[i].key && map->buckets[i].key != TOMBSTONE) + nkeys++; + + int cap = map->capacity; + while ((nkeys * 100) / cap >= LOW_WATERMARK) + cap = cap * 2; + assert(cap > 0); + + // Create a new hashmap and copy all key-values. + HashMap map2 = {0}; + map2.buckets = calloc(cap, sizeof(HashEntry)); + map2.capacity = cap; + + for (int i = 0; i < map->capacity; i++) { + HashEntry *ent = &map->buckets[i]; + if (ent->key && ent->key != TOMBSTONE) + hashmap_put2(&map2, ent->key, ent->keylen, ent->val); + } + + assert(map2.used == nkeys); + *map = map2; +} + +static bool match(HashEntry *ent, char *key, int keylen) { + return ent->key && ent->key != TOMBSTONE && + ent->keylen == keylen && memcmp(ent->key, key, keylen) == 0; +} + +static HashEntry *get_entry(HashMap *map, char *key, int keylen) { + if (!map->buckets) + return NULL; + + uint64_t hash = fnv_hash(key, keylen); + + for (int i = 0; i < map->capacity; i++) { + HashEntry *ent = &map->buckets[(hash + i) % map->capacity]; + if (match(ent, key, keylen)) + return ent; + if (ent->key == NULL) + return NULL; + } + unreachable(); +} + +static HashEntry *get_or_insert_entry(HashMap *map, char *key, int keylen) { + if (!map->buckets) { + map->buckets = calloc(INIT_SIZE, sizeof(HashEntry)); + map->capacity = INIT_SIZE; + } else if ((map->used * 100) / map->capacity >= HIGH_WATERMARK) { + rehash(map); + } + + uint64_t hash = fnv_hash(key, keylen); + + for (int i = 0; i < map->capacity; i++) { + HashEntry *ent = &map->buckets[(hash + i) % map->capacity]; + + if (match(ent, key, keylen)) + return ent; + + if (ent->key == TOMBSTONE) { + ent->key = key; + ent->keylen = keylen; + return ent; + } + + if (ent->key == NULL) { + ent->key = key; + ent->keylen = keylen; + map->used++; + return ent; + } + } + unreachable(); +} + +void *hashmap_get(HashMap *map, char *key) { + return hashmap_get2(map, key, strlen(key)); +} + +void *hashmap_get2(HashMap *map, char *key, int keylen) { + HashEntry *ent = get_entry(map, key, keylen); + return ent ? ent->val : NULL; +} + +void hashmap_put(HashMap *map, char *key, void *val) { + hashmap_put2(map, key, strlen(key), val); +} + +void hashmap_put2(HashMap *map, char *key, int keylen, void *val) { + HashEntry *ent = get_or_insert_entry(map, key, keylen); + ent->val = val; +} + +void hashmap_delete(HashMap *map, char *key) { + hashmap_delete2(map, key, strlen(key)); +} + +void hashmap_delete2(HashMap *map, char *key, int keylen) { + HashEntry *ent = get_entry(map, key, keylen); + if (ent) + ent->key = TOMBSTONE; +} + +void hashmap_test(void) { + HashMap *map = calloc(1, sizeof(HashMap)); + + for (int i = 0; i < 5000; i++) + hashmap_put(map, format("key %d", i), (void *)(size_t)i); + for (int i = 1000; i < 2000; i++) + hashmap_delete(map, format("key %d", i)); + for (int i = 1500; i < 1600; i++) + hashmap_put(map, format("key %d", i), (void *)(size_t)i); + for (int i = 6000; i < 7000; i++) + hashmap_put(map, format("key %d", i), (void *)(size_t)i); + + for (int i = 0; i < 1000; i++) + assert((size_t)hashmap_get(map, format("key %d", i)) == i); + for (int i = 1000; i < 1500; i++) + assert(hashmap_get(map, "no such key") == NULL); + for (int i = 1500; i < 1600; i++) + assert((size_t)hashmap_get(map, format("key %d", i)) == i); + for (int i = 1600; i < 2000; i++) + assert(hashmap_get(map, "no such key") == NULL); + for (int i = 2000; i < 5000; i++) + assert((size_t)hashmap_get(map, format("key %d", i)) == i); + for (int i = 5000; i < 6000; i++) + assert(hashmap_get(map, "no such key") == NULL); + for (int i = 6000; i < 7000; i++) + hashmap_put(map, format("key %d", i), (void *)(size_t)i); + + assert(hashmap_get(map, "no such key") == NULL); + printf("OK\n"); +} diff --git a/src/3p/chibicc/main.c b/src/3p/chibicc/main.c new file mode 100644 index 0000000..ffaabf4 --- /dev/null +++ b/src/3p/chibicc/main.c @@ -0,0 +1,791 @@ +#include "chibicc.h" + +typedef enum { + FILE_NONE, FILE_C, FILE_ASM, FILE_OBJ, FILE_AR, FILE_DSO, +} FileType; + +StringArray include_paths; +bool opt_fcommon = true; +bool opt_fpic; + +static FileType opt_x; +static StringArray opt_include; +static bool opt_E; +static bool opt_M; +static bool opt_MD; +static bool opt_MMD; +static bool opt_MP; +static bool opt_S; +static bool opt_c; +static bool opt_cc1; +static bool opt_hash_hash_hash; +static bool opt_static; +static bool opt_shared; +static char *opt_MF; +static char *opt_MT; +static char *opt_o; + +static StringArray ld_extra_args; +static StringArray std_include_paths; + +char *base_file; +static char *output_file; + +static StringArray input_paths; +static StringArray tmpfiles; + +static void usage(int status) { + fprintf(stderr, "chibicc [ -o ] \n"); + exit(status); +} + +static bool take_arg(char *arg) { + char *x[] = { + "-o", "-I", "-idirafter", "-include", "-x", "-MF", "-MT", "-Xlinker", + }; + + for (int i = 0; i < sizeof(x) / sizeof(*x); i++) + if (!strcmp(arg, x[i])) + return true; + return false; +} + +static void add_default_include_paths(char *argv0) { + // We expect that chibicc-specific include files are installed + // to ./include relative to argv[0]. + strarray_push(&include_paths, format("%s/include", dirname(strdup(argv0)))); + + // Add standard include paths. + strarray_push(&include_paths, "/usr/local/include"); + strarray_push(&include_paths, "/usr/include/x86_64-linux-gnu"); + strarray_push(&include_paths, "/usr/include"); + + // Keep a copy of the standard include paths for -MMD option. + for (int i = 0; i < include_paths.len; i++) + strarray_push(&std_include_paths, include_paths.data[i]); +} + +static void define(char *str) { + char *eq = strchr(str, '='); + if (eq) + define_macro(strndup(str, eq - str), eq + 1); + else + define_macro(str, "1"); +} + +static FileType parse_opt_x(char *s) { + if (!strcmp(s, "c")) + return FILE_C; + if (!strcmp(s, "assembler")) + return FILE_ASM; + if (!strcmp(s, "none")) + return FILE_NONE; + error(": unknown argument for -x: %s", s); +} + +static char *quote_makefile(char *s) { + char *buf = calloc(1, strlen(s) * 2 + 1); + + for (int i = 0, j = 0; s[i]; i++) { + switch (s[i]) { + case '$': + buf[j++] = '$'; + buf[j++] = '$'; + break; + case '#': + buf[j++] = '\\'; + buf[j++] = '#'; + break; + case ' ': + case '\t': + for (int k = i - 1; k >= 0 && s[k] == '\\'; k--) + buf[j++] = '\\'; + buf[j++] = '\\'; + buf[j++] = s[i]; + break; + default: + buf[j++] = s[i]; + break; + } + } + return buf; +} + +static void parse_args(int argc, char **argv) { + // Make sure that all command line options that take an argument + // have an argument. + for (int i = 1; i < argc; i++) + if (take_arg(argv[i])) + if (!argv[++i]) + usage(1); + + StringArray idirafter = {}; + + for (int i = 1; i < argc; i++) { + if (!strcmp(argv[i], "-###")) { + opt_hash_hash_hash = true; + continue; + } + + if (!strcmp(argv[i], "-cc1")) { + opt_cc1 = true; + continue; + } + + if (!strcmp(argv[i], "--help")) + usage(0); + + if (!strcmp(argv[i], "-o")) { + opt_o = argv[++i]; + continue; + } + + if (!strncmp(argv[i], "-o", 2)) { + opt_o = argv[i] + 2; + continue; + } + + if (!strcmp(argv[i], "-S")) { + opt_S = true; + continue; + } + + if (!strcmp(argv[i], "-fcommon")) { + opt_fcommon = true; + continue; + } + + if (!strcmp(argv[i], "-fno-common")) { + opt_fcommon = false; + continue; + } + + if (!strcmp(argv[i], "-c")) { + opt_c = true; + continue; + } + + if (!strcmp(argv[i], "-E")) { + opt_E = true; + continue; + } + + if (!strncmp(argv[i], "-I", 2)) { + strarray_push(&include_paths, argv[i] + 2); + continue; + } + + if (!strcmp(argv[i], "-D")) { + define(argv[++i]); + continue; + } + + if (!strncmp(argv[i], "-D", 2)) { + define(argv[i] + 2); + continue; + } + + if (!strcmp(argv[i], "-U")) { + undef_macro(argv[++i]); + continue; + } + + if (!strncmp(argv[i], "-U", 2)) { + undef_macro(argv[i] + 2); + continue; + } + + if (!strcmp(argv[i], "-include")) { + strarray_push(&opt_include, argv[++i]); + continue; + } + + if (!strcmp(argv[i], "-x")) { + opt_x = parse_opt_x(argv[++i]); + continue; + } + + if (!strncmp(argv[i], "-x", 2)) { + opt_x = parse_opt_x(argv[i] + 2); + continue; + } + + if (!strncmp(argv[i], "-l", 2) || !strncmp(argv[i], "-Wl,", 4)) { + strarray_push(&input_paths, argv[i]); + continue; + } + + if (!strcmp(argv[i], "-Xlinker")) { + strarray_push(&ld_extra_args, argv[++i]); + continue; + } + + if (!strcmp(argv[i], "-s")) { + strarray_push(&ld_extra_args, "-s"); + continue; + } + + if (!strcmp(argv[i], "-M")) { + opt_M = true; + continue; + } + + if (!strcmp(argv[i], "-MF")) { + opt_MF = argv[++i]; + continue; + } + + if (!strcmp(argv[i], "-MP")) { + opt_MP = true; + continue; + } + + if (!strcmp(argv[i], "-MT")) { + if (opt_MT == NULL) + opt_MT = argv[++i]; + else + opt_MT = format("%s %s", opt_MT, argv[++i]); + continue; + } + + if (!strcmp(argv[i], "-MD")) { + opt_MD = true; + continue; + } + + if (!strcmp(argv[i], "-MQ")) { + if (opt_MT == NULL) + opt_MT = quote_makefile(argv[++i]); + else + opt_MT = format("%s %s", opt_MT, quote_makefile(argv[++i])); + continue; + } + + if (!strcmp(argv[i], "-MMD")) { + opt_MD = opt_MMD = true; + continue; + } + + if (!strcmp(argv[i], "-fpic") || !strcmp(argv[i], "-fPIC")) { + opt_fpic = true; + continue; + } + + if (!strcmp(argv[i], "-cc1-input")) { + base_file = argv[++i]; + continue; + } + + if (!strcmp(argv[i], "-cc1-output")) { + output_file = argv[++i]; + continue; + } + + if (!strcmp(argv[i], "-idirafter")) { + strarray_push(&idirafter, argv[i++]); + continue; + } + + if (!strcmp(argv[i], "-static")) { + opt_static = true; + strarray_push(&ld_extra_args, "-static"); + continue; + } + + if (!strcmp(argv[i], "-shared")) { + opt_shared = true; + strarray_push(&ld_extra_args, "-shared"); + continue; + } + + if (!strcmp(argv[i], "-L")) { + strarray_push(&ld_extra_args, "-L"); + strarray_push(&ld_extra_args, argv[++i]); + continue; + } + + if (!strncmp(argv[i], "-L", 2)) { + strarray_push(&ld_extra_args, "-L"); + strarray_push(&ld_extra_args, argv[i] + 2); + continue; + } + + if (!strcmp(argv[i], "-hashmap-test")) { + hashmap_test(); + exit(0); + } + + // These options are ignored for now. + if (!strncmp(argv[i], "-O", 2) || + !strncmp(argv[i], "-W", 2) || + !strncmp(argv[i], "-g", 2) || + !strncmp(argv[i], "-std=", 5) || + !strcmp(argv[i], "-ffreestanding") || + !strcmp(argv[i], "-fno-builtin") || + !strcmp(argv[i], "-fno-omit-frame-pointer") || + !strcmp(argv[i], "-fno-stack-protector") || + !strcmp(argv[i], "-fno-strict-aliasing") || + !strcmp(argv[i], "-m64") || + !strcmp(argv[i], "-mno-red-zone") || + !strcmp(argv[i], "-w")) + continue; + + if (argv[i][0] == '-' && argv[i][1] != '\0') + error("unknown argument: %s", argv[i]); + + strarray_push(&input_paths, argv[i]); + } + + for (int i = 0; i < idirafter.len; i++) + strarray_push(&include_paths, idirafter.data[i]); + + if (input_paths.len == 0) + error("no input files"); + + // -E implies that the input is the C macro language. + if (opt_E) + opt_x = FILE_C; +} + +static FILE *open_file(char *path) { + if (!path || strcmp(path, "-") == 0) + return stdout; + + FILE *out = fopen(path, "w"); + if (!out) + error("cannot open output file: %s: %s", path, strerror(errno)); + return out; +} + +static bool endswith(char *p, char *q) { + int len1 = strlen(p); + int len2 = strlen(q); + return (len1 >= len2) && !strcmp(p + len1 - len2, q); +} + +// Replace file extension +static char *replace_extn(char *tmpl, char *extn) { + char *filename = basename(strdup(tmpl)); + char *dot = strrchr(filename, '.'); + if (dot) + *dot = '\0'; + return format("%s%s", filename, extn); +} + +static void cleanup(void) { + for (int i = 0; i < tmpfiles.len; i++) + unlink(tmpfiles.data[i]); +} + +static char *create_tmpfile(void) { + char *path = strdup("/tmp/chibicc-XXXXXX"); + int fd = mkstemp(path); + if (fd == -1) + error("mkstemp failed: %s", strerror(errno)); + close(fd); + + strarray_push(&tmpfiles, path); + return path; +} + +static void run_subprocess(char **argv) { + // If -### is given, dump the subprocess's command line. + if (opt_hash_hash_hash) { + fprintf(stderr, "%s", argv[0]); + for (int i = 1; argv[i]; i++) + fprintf(stderr, " %s", argv[i]); + fprintf(stderr, "\n"); + } + + if (fork() == 0) { + // Child process. Run a new command. + execvp(argv[0], argv); + fprintf(stderr, "exec failed: %s: %s\n", argv[0], strerror(errno)); + _exit(1); + } + + // Wait for the child process to finish. + int status; + while (wait(&status) > 0); + if (status != 0) + exit(1); +} + +static void run_cc1(int argc, char **argv, char *input, char *output) { + char **args = calloc(argc + 10, sizeof(char *)); + memcpy(args, argv, argc * sizeof(char *)); + args[argc++] = "-cc1"; + + if (input) { + args[argc++] = "-cc1-input"; + args[argc++] = input; + } + + if (output) { + args[argc++] = "-cc1-output"; + args[argc++] = output; + } + + run_subprocess(args); +} + +// Print tokens to stdout. Used for -E. +static void print_tokens(Token *tok) { + FILE *out = open_file(opt_o ? opt_o : "-"); + + int line = 1; + for (; tok->kind != TK_EOF; tok = tok->next) { + if (line > 1 && tok->at_bol) + fprintf(out, "\n"); + if (tok->has_space && !tok->at_bol) + fprintf(out, " "); + fprintf(out, "%.*s", tok->len, tok->loc); + line++; + } + fprintf(out, "\n"); +} + +static bool in_std_include_path(char *path) { + for (int i = 0; i < std_include_paths.len; i++) { + char *dir = std_include_paths.data[i]; + int len = strlen(dir); + if (strncmp(dir, path, len) == 0 && path[len] == '/') + return true; + } + return false; +} + +// If -M options is given, the compiler write a list of input files to +// stdout in a format that "make" command can read. This feature is +// used to automate file dependency management. +static void print_dependencies(void) { + char *path; + if (opt_MF) + path = opt_MF; + else if (opt_MD) + path = replace_extn(opt_o ? opt_o : base_file, ".d"); + else if (opt_o) + path = opt_o; + else + path = "-"; + + FILE *out = open_file(path); + if (opt_MT) + fprintf(out, "%s:", opt_MT); + else + fprintf(out, "%s:", quote_makefile(replace_extn(base_file, ".o"))); + + File **files = get_input_files(); + + for (int i = 0; files[i]; i++) { + if (opt_MMD && in_std_include_path(files[i]->name)) + continue; + fprintf(out, " \\\n %s", files[i]->name); + } + + fprintf(out, "\n\n"); + + if (opt_MP) { + for (int i = 1; files[i]; i++) { + if (opt_MMD && in_std_include_path(files[i]->name)) + continue; + fprintf(out, "%s:\n\n", quote_makefile(files[i]->name)); + } + } +} + +static Token *must_tokenize_file(char *path) { + Token *tok = tokenize_file(path); + if (!tok) + error("%s: %s", path, strerror(errno)); + return tok; +} + +static Token *append_tokens(Token *tok1, Token *tok2) { + if (!tok1 || tok1->kind == TK_EOF) + return tok2; + + Token *t = tok1; + while (t->next->kind != TK_EOF) + t = t->next; + t->next = tok2; + return tok1; +} + +static void cc1(void) { + Token *tok = NULL; + + // Process -include option + for (int i = 0; i < opt_include.len; i++) { + char *incl = opt_include.data[i]; + + char *path; + if (file_exists(incl)) { + path = incl; + } else { + path = search_include_paths(incl); + if (!path) + error("-include: %s: %s", incl, strerror(errno)); + } + + Token *tok2 = must_tokenize_file(path); + tok = append_tokens(tok, tok2); + } + + // Tokenize and parse. + Token *tok2 = must_tokenize_file(base_file); + tok = append_tokens(tok, tok2); + tok = preprocess(tok); + + // If -M or -MD are given, print file dependencies. + if (opt_M || opt_MD) { + print_dependencies(); + if (opt_M) + return; + } + + // If -E is given, print out preprocessed C code as a result. + if (opt_E) { + print_tokens(tok); + return; + } + + Obj *prog = parse(tok); + + // Open a temporary output buffer. + char *buf; + size_t buflen; + FILE *output_buf = open_memstream(&buf, &buflen); + + // Traverse the AST to emit assembly. + codegen(prog, output_buf); + fclose(output_buf); + + // Write the asembly text to a file. + FILE *out = open_file(output_file); + fwrite(buf, buflen, 1, out); + fclose(out); +} + +static void assemble(char *input, char *output) { + char *cmd[] = {"as", "-c", input, "-o", output, NULL}; + run_subprocess(cmd); +} + +static char *find_file(char *pattern) { + char *path = NULL; + glob_t buf = {}; + glob(pattern, 0, NULL, &buf); + if (buf.gl_pathc > 0) + path = strdup(buf.gl_pathv[buf.gl_pathc - 1]); + globfree(&buf); + return path; +} + +// Returns true if a given file exists. +bool file_exists(char *path) { + struct stat st; + return !stat(path, &st); +} + +static char *find_libpath(void) { + if (file_exists("/usr/lib/x86_64-linux-gnu/crti.o")) + return "/usr/lib/x86_64-linux-gnu"; + if (file_exists("/usr/lib64/crti.o")) + return "/usr/lib64"; + error("library path is not found"); +} + +static char *find_gcc_libpath(void) { + char *paths[] = { + "/usr/lib/gcc/x86_64-linux-gnu/*/crtbegin.o", + "/usr/lib/gcc/x86_64-pc-linux-gnu/*/crtbegin.o", // For Gentoo + "/usr/lib/gcc/x86_64-redhat-linux/*/crtbegin.o", // For Fedora + }; + + for (int i = 0; i < sizeof(paths) / sizeof(*paths); i++) { + char *path = find_file(paths[i]); + if (path) + return dirname(path); + } + + error("gcc library path is not found"); +} + +static void run_linker(StringArray *inputs, char *output) { + StringArray arr = {}; + + strarray_push(&arr, "ld"); + strarray_push(&arr, "-o"); + strarray_push(&arr, output); + strarray_push(&arr, "-m"); + strarray_push(&arr, "elf_x86_64"); + + char *libpath = find_libpath(); + char *gcc_libpath = find_gcc_libpath(); + + if (opt_shared) { + strarray_push(&arr, format("%s/crti.o", libpath)); + strarray_push(&arr, format("%s/crtbeginS.o", gcc_libpath)); + } else { + strarray_push(&arr, format("%s/crt1.o", libpath)); + strarray_push(&arr, format("%s/crti.o", libpath)); + strarray_push(&arr, format("%s/crtbegin.o", gcc_libpath)); + } + + strarray_push(&arr, format("-L%s", gcc_libpath)); + strarray_push(&arr, "-L/usr/lib/x86_64-linux-gnu"); + strarray_push(&arr, "-L/usr/lib64"); + strarray_push(&arr, "-L/lib64"); + strarray_push(&arr, "-L/usr/lib/x86_64-linux-gnu"); + strarray_push(&arr, "-L/usr/lib/x86_64-pc-linux-gnu"); + strarray_push(&arr, "-L/usr/lib/x86_64-redhat-linux"); + strarray_push(&arr, "-L/usr/lib"); + strarray_push(&arr, "-L/lib"); + + if (!opt_static) { + strarray_push(&arr, "-dynamic-linker"); + strarray_push(&arr, "/lib64/ld-linux-x86-64.so.2"); + } + + for (int i = 0; i < ld_extra_args.len; i++) + strarray_push(&arr, ld_extra_args.data[i]); + + for (int i = 0; i < inputs->len; i++) + strarray_push(&arr, inputs->data[i]); + + if (opt_static) { + strarray_push(&arr, "--start-group"); + strarray_push(&arr, "-lgcc"); + strarray_push(&arr, "-lgcc_eh"); + strarray_push(&arr, "-lc"); + strarray_push(&arr, "--end-group"); + } else { + strarray_push(&arr, "-lc"); + strarray_push(&arr, "-lgcc"); + strarray_push(&arr, "--as-needed"); + strarray_push(&arr, "-lgcc_s"); + strarray_push(&arr, "--no-as-needed"); + } + + if (opt_shared) + strarray_push(&arr, format("%s/crtendS.o", gcc_libpath)); + else + strarray_push(&arr, format("%s/crtend.o", gcc_libpath)); + + strarray_push(&arr, format("%s/crtn.o", libpath)); + strarray_push(&arr, NULL); + + run_subprocess(arr.data); +} + +static FileType get_file_type(char *filename) { + if (opt_x != FILE_NONE) + return opt_x; + + if (endswith(filename, ".a")) + return FILE_AR; + if (endswith(filename, ".so")) + return FILE_DSO; + if (endswith(filename, ".o")) + return FILE_OBJ; + if (endswith(filename, ".c")) + return FILE_C; + if (endswith(filename, ".s")) + return FILE_ASM; + + error(": unknown file extension: %s", filename); +} + +int main(int argc, char **argv) { + atexit(cleanup); + init_macros(); + parse_args(argc, argv); + + if (opt_cc1) { + add_default_include_paths(argv[0]); + cc1(); + return 0; + } + + if (input_paths.len > 1 && opt_o && (opt_c || opt_S | opt_E)) + error("cannot specify '-o' with '-c,' '-S' or '-E' with multiple files"); + + StringArray ld_args = {}; + + for (int i = 0; i < input_paths.len; i++) { + char *input = input_paths.data[i]; + + if (!strncmp(input, "-l", 2)) { + strarray_push(&ld_args, input); + continue; + } + + if (!strncmp(input, "-Wl,", 4)) { + char *s = strdup(input + 4); + char *arg = strtok(s, ","); + while (arg) { + strarray_push(&ld_args, arg); + arg = strtok(NULL, ","); + } + continue; + } + + char *output; + if (opt_o) + output = opt_o; + else if (opt_S) + output = replace_extn(input, ".s"); + else + output = replace_extn(input, ".o"); + + FileType type = get_file_type(input); + + // Handle .o or .a + if (type == FILE_OBJ || type == FILE_AR || type == FILE_DSO) { + strarray_push(&ld_args, input); + continue; + } + + // Handle .s + if (type == FILE_ASM) { + if (!opt_S) + assemble(input, output); + continue; + } + + assert(type == FILE_C); + + // Just preprocess + if (opt_E || opt_M) { + run_cc1(argc, argv, input, NULL); + continue; + } + + // Compile + if (opt_S) { + run_cc1(argc, argv, input, output); + continue; + } + + // Compile and assemble + if (opt_c) { + char *tmp = create_tmpfile(); + run_cc1(argc, argv, input, tmp); + assemble(tmp, output); + continue; + } + + // Compile, assemble and link + char *tmp1 = create_tmpfile(); + char *tmp2 = create_tmpfile(); + run_cc1(argc, argv, input, tmp1); + assemble(tmp1, tmp2); + strarray_push(&ld_args, tmp2); + continue; + } + + if (ld_args.len > 0) + run_linker(&ld_args, opt_o ? opt_o : "a.out"); + return 0; +} diff --git a/src/3p/chibicc/parse.c b/src/3p/chibicc/parse.c new file mode 100644 index 0000000..6acaeb8 --- /dev/null +++ b/src/3p/chibicc/parse.c @@ -0,0 +1,3368 @@ +// This file contains a recursive descent parser for C. +// +// Most functions in this file are named after the symbols they are +// supposed to read from an input token list. For example, stmt() is +// responsible for reading a statement from a token list. The function +// then construct an AST node representing a statement. +// +// Each function conceptually returns two values, an AST node and +// remaining part of the input tokens. Since C doesn't support +// multiple return values, the remaining tokens are returned to the +// caller via a pointer argument. +// +// Input tokens are represented by a linked list. Unlike many recursive +// descent parsers, we don't have the notion of the "input token stream". +// Most parsing functions don't change the global state of the parser. +// So it is very easy to lookahead arbitrary number of tokens in this +// parser. + +#include "chibicc.h" + +// Scope for local variables, global variables, typedefs +// or enum constants +typedef struct { + Obj *var; + Type *type_def; + Type *enum_ty; + int enum_val; +} VarScope; + +// Represents a block scope. +typedef struct Scope Scope; +struct Scope { + Scope *next; + + // C has two block scopes; one is for variables/typedefs and + // the other is for struct/union/enum tags. + HashMap vars; + HashMap tags; +}; + +// Variable attributes such as typedef or extern. +typedef struct { + bool is_typedef; + bool is_static; + bool is_extern; + bool is_inline; + bool is_tls; + int align; +} VarAttr; + +// This struct represents a variable initializer. Since initializers +// can be nested (e.g. `int x[2][2] = {{1, 2}, {3, 4}}`), this struct +// is a tree data structure. +typedef struct Initializer Initializer; +struct Initializer { + Initializer *next; + Type *ty; + Token *tok; + bool is_flexible; + + // If it's not an aggregate type and has an initializer, + // `expr` has an initialization expression. + Node *expr; + + // If it's an initializer for an aggregate type (e.g. array or struct), + // `children` has initializers for its children. + Initializer **children; + + // Only one member can be initialized for a union. + // `mem` is used to clarify which member is initialized. + Member *mem; +}; + +// For local variable initializer. +typedef struct InitDesg InitDesg; +struct InitDesg { + InitDesg *next; + int idx; + Member *member; + Obj *var; +}; + +// All local variable instances created during parsing are +// accumulated to this list. +static Obj *locals; + +// Likewise, global variables are accumulated to this list. +static Obj *globals; + +static Scope *scope = &(Scope){}; + +// Points to the function object the parser is currently parsing. +static Obj *current_fn; + +// Lists of all goto statements and labels in the curent function. +static Node *gotos; +static Node *labels; + +// Current "goto" and "continue" jump targets. +static char *brk_label; +static char *cont_label; + +// Points to a node representing a switch if we are parsing +// a switch statement. Otherwise, NULL. +static Node *current_switch; + +static Obj *builtin_alloca; + +static bool is_typename(Token *tok); +static Type *declspec(Token **rest, Token *tok, VarAttr *attr); +static Type *typename(Token **rest, Token *tok); +static Type *enum_specifier(Token **rest, Token *tok); +static Type *typeof_specifier(Token **rest, Token *tok); +static Type *type_suffix(Token **rest, Token *tok, Type *ty); +static Type *declarator(Token **rest, Token *tok, Type *ty); +static Node *declaration(Token **rest, Token *tok, Type *basety, VarAttr *attr); +static void array_initializer2(Token **rest, Token *tok, Initializer *init, int i); +static void struct_initializer2(Token **rest, Token *tok, Initializer *init, Member *mem); +static void initializer2(Token **rest, Token *tok, Initializer *init); +static Initializer *initializer(Token **rest, Token *tok, Type *ty, Type **new_ty); +static Node *lvar_initializer(Token **rest, Token *tok, Obj *var); +static void gvar_initializer(Token **rest, Token *tok, Obj *var); +static Node *compound_stmt(Token **rest, Token *tok); +static Node *stmt(Token **rest, Token *tok); +static Node *expr_stmt(Token **rest, Token *tok); +static Node *expr(Token **rest, Token *tok); +static int64_t eval(Node *node); +static int64_t eval2(Node *node, char ***label); +static int64_t eval_rval(Node *node, char ***label); +static bool is_const_expr(Node *node); +static Node *assign(Token **rest, Token *tok); +static Node *logor(Token **rest, Token *tok); +static double eval_double(Node *node); +static Node *conditional(Token **rest, Token *tok); +static Node *logand(Token **rest, Token *tok); +static Node *bitor(Token **rest, Token *tok); +static Node *bitxor(Token **rest, Token *tok); +static Node *bitand(Token **rest, Token *tok); +static Node *equality(Token **rest, Token *tok); +static Node *relational(Token **rest, Token *tok); +static Node *shift(Token **rest, Token *tok); +static Node *add(Token **rest, Token *tok); +static Node *new_add(Node *lhs, Node *rhs, Token *tok); +static Node *new_sub(Node *lhs, Node *rhs, Token *tok); +static Node *mul(Token **rest, Token *tok); +static Node *cast(Token **rest, Token *tok); +static Member *get_struct_member(Type *ty, Token *tok); +static Type *struct_decl(Token **rest, Token *tok); +static Type *union_decl(Token **rest, Token *tok); +static Node *postfix(Token **rest, Token *tok); +static Node *funcall(Token **rest, Token *tok, Node *node); +static Node *unary(Token **rest, Token *tok); +static Node *primary(Token **rest, Token *tok); +static Token *parse_typedef(Token *tok, Type *basety); +static bool is_function(Token *tok); +static Token *function(Token *tok, Type *basety, VarAttr *attr); +static Token *global_variable(Token *tok, Type *basety, VarAttr *attr); + +static int align_down(int n, int align) { + return align_to(n - align + 1, align); +} + +static void enter_scope(void) { + Scope *sc = calloc(1, sizeof(Scope)); + sc->next = scope; + scope = sc; +} + +static void leave_scope(void) { + scope = scope->next; +} + +// Find a variable by name. +static VarScope *find_var(Token *tok) { + for (Scope *sc = scope; sc; sc = sc->next) { + VarScope *sc2 = hashmap_get2(&sc->vars, tok->loc, tok->len); + if (sc2) + return sc2; + } + return NULL; +} + +static Type *find_tag(Token *tok) { + for (Scope *sc = scope; sc; sc = sc->next) { + Type *ty = hashmap_get2(&sc->tags, tok->loc, tok->len); + if (ty) + return ty; + } + return NULL; +} + +static Node *new_node(NodeKind kind, Token *tok) { + Node *node = calloc(1, sizeof(Node)); + node->kind = kind; + node->tok = tok; + return node; +} + +static Node *new_binary(NodeKind kind, Node *lhs, Node *rhs, Token *tok) { + Node *node = new_node(kind, tok); + node->lhs = lhs; + node->rhs = rhs; + return node; +} + +static Node *new_unary(NodeKind kind, Node *expr, Token *tok) { + Node *node = new_node(kind, tok); + node->lhs = expr; + return node; +} + +static Node *new_num(int64_t val, Token *tok) { + Node *node = new_node(ND_NUM, tok); + node->val = val; + return node; +} + +static Node *new_long(int64_t val, Token *tok) { + Node *node = new_node(ND_NUM, tok); + node->val = val; + node->ty = ty_long; + return node; +} + +static Node *new_ulong(long val, Token *tok) { + Node *node = new_node(ND_NUM, tok); + node->val = val; + node->ty = ty_ulong; + return node; +} + +static Node *new_var_node(Obj *var, Token *tok) { + Node *node = new_node(ND_VAR, tok); + node->var = var; + return node; +} + +static Node *new_vla_ptr(Obj *var, Token *tok) { + Node *node = new_node(ND_VLA_PTR, tok); + node->var = var; + return node; +} + +Node *new_cast(Node *expr, Type *ty) { + add_type(expr); + + Node *node = calloc(1, sizeof(Node)); + node->kind = ND_CAST; + node->tok = expr->tok; + node->lhs = expr; + node->ty = copy_type(ty); + return node; +} + +static VarScope *push_scope(char *name) { + VarScope *sc = calloc(1, sizeof(VarScope)); + hashmap_put(&scope->vars, name, sc); + return sc; +} + +static Initializer *new_initializer(Type *ty, bool is_flexible) { + Initializer *init = calloc(1, sizeof(Initializer)); + init->ty = ty; + + if (ty->kind == TY_ARRAY) { + if (is_flexible && ty->size < 0) { + init->is_flexible = true; + return init; + } + + init->children = calloc(ty->array_len, sizeof(Initializer *)); + for (int i = 0; i < ty->array_len; i++) + init->children[i] = new_initializer(ty->base, false); + return init; + } + + if (ty->kind == TY_STRUCT || ty->kind == TY_UNION) { + // Count the number of struct members. + int len = 0; + for (Member *mem = ty->members; mem; mem = mem->next) + len++; + + init->children = calloc(len, sizeof(Initializer *)); + + for (Member *mem = ty->members; mem; mem = mem->next) { + if (is_flexible && ty->is_flexible && !mem->next) { + Initializer *child = calloc(1, sizeof(Initializer)); + child->ty = mem->ty; + child->is_flexible = true; + init->children[mem->idx] = child; + } else { + init->children[mem->idx] = new_initializer(mem->ty, false); + } + } + return init; + } + + return init; +} + +static Obj *new_var(char *name, Type *ty) { + Obj *var = calloc(1, sizeof(Obj)); + var->name = name; + var->ty = ty; + var->align = ty->align; + push_scope(name)->var = var; + return var; +} + +static Obj *new_lvar(char *name, Type *ty) { + Obj *var = new_var(name, ty); + var->is_local = true; + var->next = locals; + locals = var; + return var; +} + +static Obj *new_gvar(char *name, Type *ty) { + Obj *var = new_var(name, ty); + var->next = globals; + var->is_static = true; + var->is_definition = true; + globals = var; + return var; +} + +static char *new_unique_name(void) { + static int id = 0; + return format(".L..%d", id++); +} + +static Obj *new_anon_gvar(Type *ty) { + return new_gvar(new_unique_name(), ty); +} + +static Obj *new_string_literal(char *p, Type *ty) { + Obj *var = new_anon_gvar(ty); + var->init_data = p; + return var; +} + +static char *get_ident(Token *tok) { + if (tok->kind != TK_IDENT) + error_tok(tok, "expected an identifier"); + return strndup(tok->loc, tok->len); +} + +static Type *find_typedef(Token *tok) { + if (tok->kind == TK_IDENT) { + VarScope *sc = find_var(tok); + if (sc) + return sc->type_def; + } + return NULL; +} + +static void push_tag_scope(Token *tok, Type *ty) { + hashmap_put2(&scope->tags, tok->loc, tok->len, ty); +} + +// declspec = ("void" | "_Bool" | "char" | "short" | "int" | "long" +// | "typedef" | "static" | "extern" | "inline" +// | "_Thread_local" | "__thread" +// | "signed" | "unsigned" +// | struct-decl | union-decl | typedef-name +// | enum-specifier | typeof-specifier +// | "const" | "volatile" | "auto" | "register" | "restrict" +// | "__restrict" | "__restrict__" | "_Noreturn")+ +// +// The order of typenames in a type-specifier doesn't matter. For +// example, `int long static` means the same as `static long int`. +// That can also be written as `static long` because you can omit +// `int` if `long` or `short` are specified. However, something like +// `char int` is not a valid type specifier. We have to accept only a +// limited combinations of the typenames. +// +// In this function, we count the number of occurrences of each typename +// while keeping the "current" type object that the typenames up +// until that point represent. When we reach a non-typename token, +// we returns the current type object. +static Type *declspec(Token **rest, Token *tok, VarAttr *attr) { + // We use a single integer as counters for all typenames. + // For example, bits 0 and 1 represents how many times we saw the + // keyword "void" so far. With this, we can use a switch statement + // as you can see below. + enum { + VOID = 1 << 0, + BOOL = 1 << 2, + CHAR = 1 << 4, + SHORT = 1 << 6, + INT = 1 << 8, + LONG = 1 << 10, + FLOAT = 1 << 12, + DOUBLE = 1 << 14, + OTHER = 1 << 16, + SIGNED = 1 << 17, + UNSIGNED = 1 << 18, + }; + + Type *ty = ty_int; + int counter = 0; + bool is_atomic = false; + + while (is_typename(tok)) { + // Handle storage class specifiers. + if (equal(tok, "typedef") || equal(tok, "static") || equal(tok, "extern") || + equal(tok, "inline") || equal(tok, "_Thread_local") || equal(tok, "__thread")) { + if (!attr) + error_tok(tok, "storage class specifier is not allowed in this context"); + + if (equal(tok, "typedef")) + attr->is_typedef = true; + else if (equal(tok, "static")) + attr->is_static = true; + else if (equal(tok, "extern")) + attr->is_extern = true; + else if (equal(tok, "inline")) + attr->is_inline = true; + else + attr->is_tls = true; + + if (attr->is_typedef && + attr->is_static + attr->is_extern + attr->is_inline + attr->is_tls > 1) + error_tok(tok, "typedef may not be used together with static," + " extern, inline, __thread or _Thread_local"); + tok = tok->next; + continue; + } + + // These keywords are recognized but ignored. + if (consume(&tok, tok, "const") || consume(&tok, tok, "volatile") || + consume(&tok, tok, "auto") || consume(&tok, tok, "register") || + consume(&tok, tok, "restrict") || consume(&tok, tok, "__restrict") || + consume(&tok, tok, "__restrict__") || consume(&tok, tok, "_Noreturn")) + continue; + + if (equal(tok, "_Atomic")) { + tok = tok->next; + if (equal(tok , "(")) { + ty = typename(&tok, tok->next); + tok = skip(tok, ")"); + } + is_atomic = true; + continue; + } + + if (equal(tok, "_Alignas")) { + if (!attr) + error_tok(tok, "_Alignas is not allowed in this context"); + tok = skip(tok->next, "("); + + if (is_typename(tok)) + attr->align = typename(&tok, tok)->align; + else + attr->align = const_expr(&tok, tok); + tok = skip(tok, ")"); + continue; + } + + // Handle user-defined types. + Type *ty2 = find_typedef(tok); + if (equal(tok, "struct") || equal(tok, "union") || equal(tok, "enum") || + equal(tok, "typeof") || ty2) { + if (counter) + break; + + if (equal(tok, "struct")) { + ty = struct_decl(&tok, tok->next); + } else if (equal(tok, "union")) { + ty = union_decl(&tok, tok->next); + } else if (equal(tok, "enum")) { + ty = enum_specifier(&tok, tok->next); + } else if (equal(tok, "typeof")) { + ty = typeof_specifier(&tok, tok->next); + } else { + ty = ty2; + tok = tok->next; + } + + counter += OTHER; + continue; + } + + // Handle built-in types. + if (equal(tok, "void")) + counter += VOID; + else if (equal(tok, "_Bool")) + counter += BOOL; + else if (equal(tok, "char")) + counter += CHAR; + else if (equal(tok, "short")) + counter += SHORT; + else if (equal(tok, "int")) + counter += INT; + else if (equal(tok, "long")) + counter += LONG; + else if (equal(tok, "float")) + counter += FLOAT; + else if (equal(tok, "double")) + counter += DOUBLE; + else if (equal(tok, "signed")) + counter |= SIGNED; + else if (equal(tok, "unsigned")) + counter |= UNSIGNED; + else + unreachable(); + + switch (counter) { + case VOID: + ty = ty_void; + break; + case BOOL: + ty = ty_bool; + break; + case CHAR: + case SIGNED + CHAR: + ty = ty_char; + break; + case UNSIGNED + CHAR: + ty = ty_uchar; + break; + case SHORT: + case SHORT + INT: + case SIGNED + SHORT: + case SIGNED + SHORT + INT: + ty = ty_short; + break; + case UNSIGNED + SHORT: + case UNSIGNED + SHORT + INT: + ty = ty_ushort; + break; + case INT: + case SIGNED: + case SIGNED + INT: + ty = ty_int; + break; + case UNSIGNED: + case UNSIGNED + INT: + ty = ty_uint; + break; + case LONG: + case LONG + INT: + case LONG + LONG: + case LONG + LONG + INT: + case SIGNED + LONG: + case SIGNED + LONG + INT: + case SIGNED + LONG + LONG: + case SIGNED + LONG + LONG + INT: + ty = ty_long; + break; + case UNSIGNED + LONG: + case UNSIGNED + LONG + INT: + case UNSIGNED + LONG + LONG: + case UNSIGNED + LONG + LONG + INT: + ty = ty_ulong; + break; + case FLOAT: + ty = ty_float; + break; + case DOUBLE: + ty = ty_double; + break; + case LONG + DOUBLE: + ty = ty_ldouble; + break; + default: + error_tok(tok, "invalid type"); + } + + tok = tok->next; + } + + if (is_atomic) { + ty = copy_type(ty); + ty->is_atomic = true; + } + + *rest = tok; + return ty; +} + +// func-params = ("void" | param ("," param)* ("," "...")?)? ")" +// param = declspec declarator +static Type *func_params(Token **rest, Token *tok, Type *ty) { + if (equal(tok, "void") && equal(tok->next, ")")) { + *rest = tok->next->next; + return func_type(ty); + } + + Type head = {}; + Type *cur = &head; + bool is_variadic = false; + + while (!equal(tok, ")")) { + if (cur != &head) + tok = skip(tok, ","); + + if (equal(tok, "...")) { + is_variadic = true; + tok = tok->next; + skip(tok, ")"); + break; + } + + Type *ty2 = declspec(&tok, tok, NULL); + ty2 = declarator(&tok, tok, ty2); + + Token *name = ty2->name; + + if (ty2->kind == TY_ARRAY) { + // "array of T" is converted to "pointer to T" only in the parameter + // context. For example, *argv[] is converted to **argv by this. + ty2 = pointer_to(ty2->base); + ty2->name = name; + } else if (ty2->kind == TY_FUNC) { + // Likewise, a function is converted to a pointer to a function + // only in the parameter context. + ty2 = pointer_to(ty2); + ty2->name = name; + } + + cur = cur->next = copy_type(ty2); + } + + if (cur == &head) + is_variadic = true; + + ty = func_type(ty); + ty->params = head.next; + ty->is_variadic = is_variadic; + *rest = tok->next; + return ty; +} + +// array-dimensions = ("static" | "restrict")* const-expr? "]" type-suffix +static Type *array_dimensions(Token **rest, Token *tok, Type *ty) { + while (equal(tok, "static") || equal(tok, "restrict")) + tok = tok->next; + + if (equal(tok, "]")) { + ty = type_suffix(rest, tok->next, ty); + return array_of(ty, -1); + } + + Node *expr = conditional(&tok, tok); + tok = skip(tok, "]"); + ty = type_suffix(rest, tok, ty); + + if (ty->kind == TY_VLA || !is_const_expr(expr)) + return vla_of(ty, expr); + return array_of(ty, eval(expr)); +} + +// type-suffix = "(" func-params +// | "[" array-dimensions +// | ε +static Type *type_suffix(Token **rest, Token *tok, Type *ty) { + if (equal(tok, "(")) + return func_params(rest, tok->next, ty); + + if (equal(tok, "[")) + return array_dimensions(rest, tok->next, ty); + + *rest = tok; + return ty; +} + +// pointers = ("*" ("const" | "volatile" | "restrict")*)* +static Type *pointers(Token **rest, Token *tok, Type *ty) { + while (consume(&tok, tok, "*")) { + ty = pointer_to(ty); + while (equal(tok, "const") || equal(tok, "volatile") || equal(tok, "restrict") || + equal(tok, "__restrict") || equal(tok, "__restrict__")) + tok = tok->next; + } + *rest = tok; + return ty; +} + +// declarator = pointers ("(" ident ")" | "(" declarator ")" | ident) type-suffix +static Type *declarator(Token **rest, Token *tok, Type *ty) { + ty = pointers(&tok, tok, ty); + + if (equal(tok, "(")) { + Token *start = tok; + Type dummy = {}; + declarator(&tok, start->next, &dummy); + tok = skip(tok, ")"); + ty = type_suffix(rest, tok, ty); + return declarator(&tok, start->next, ty); + } + + Token *name = NULL; + Token *name_pos = tok; + + if (tok->kind == TK_IDENT) { + name = tok; + tok = tok->next; + } + + ty = type_suffix(rest, tok, ty); + ty->name = name; + ty->name_pos = name_pos; + return ty; +} + +// abstract-declarator = pointers ("(" abstract-declarator ")")? type-suffix +static Type *abstract_declarator(Token **rest, Token *tok, Type *ty) { + ty = pointers(&tok, tok, ty); + + if (equal(tok, "(")) { + Token *start = tok; + Type dummy = {}; + abstract_declarator(&tok, start->next, &dummy); + tok = skip(tok, ")"); + ty = type_suffix(rest, tok, ty); + return abstract_declarator(&tok, start->next, ty); + } + + return type_suffix(rest, tok, ty); +} + +// type-name = declspec abstract-declarator +static Type *typename(Token **rest, Token *tok) { + Type *ty = declspec(&tok, tok, NULL); + return abstract_declarator(rest, tok, ty); +} + +static bool is_end(Token *tok) { + return equal(tok, "}") || (equal(tok, ",") && equal(tok->next, "}")); +} + +static bool consume_end(Token **rest, Token *tok) { + if (equal(tok, "}")) { + *rest = tok->next; + return true; + } + + if (equal(tok, ",") && equal(tok->next, "}")) { + *rest = tok->next->next; + return true; + } + + return false; +} + +// enum-specifier = ident? "{" enum-list? "}" +// | ident ("{" enum-list? "}")? +// +// enum-list = ident ("=" num)? ("," ident ("=" num)?)* ","? +static Type *enum_specifier(Token **rest, Token *tok) { + Type *ty = enum_type(); + + // Read a struct tag. + Token *tag = NULL; + if (tok->kind == TK_IDENT) { + tag = tok; + tok = tok->next; + } + + if (tag && !equal(tok, "{")) { + Type *ty = find_tag(tag); + if (!ty) + error_tok(tag, "unknown enum type"); + if (ty->kind != TY_ENUM) + error_tok(tag, "not an enum tag"); + *rest = tok; + return ty; + } + + tok = skip(tok, "{"); + + // Read an enum-list. + int i = 0; + int val = 0; + while (!consume_end(rest, tok)) { + if (i++ > 0) + tok = skip(tok, ","); + + char *name = get_ident(tok); + tok = tok->next; + + if (equal(tok, "=")) + val = const_expr(&tok, tok->next); + + VarScope *sc = push_scope(name); + sc->enum_ty = ty; + sc->enum_val = val++; + } + + if (tag) + push_tag_scope(tag, ty); + return ty; +} + +// typeof-specifier = "(" (expr | typename) ")" +static Type *typeof_specifier(Token **rest, Token *tok) { + tok = skip(tok, "("); + + Type *ty; + if (is_typename(tok)) { + ty = typename(&tok, tok); + } else { + Node *node = expr(&tok, tok); + add_type(node); + ty = node->ty; + } + *rest = skip(tok, ")"); + return ty; +} + +// Generate code for computing a VLA size. +static Node *compute_vla_size(Type *ty, Token *tok) { + Node *node = new_node(ND_NULL_EXPR, tok); + if (ty->base) + node = new_binary(ND_COMMA, node, compute_vla_size(ty->base, tok), tok); + + if (ty->kind != TY_VLA) + return node; + + Node *base_sz; + if (ty->base->kind == TY_VLA) + base_sz = new_var_node(ty->base->vla_size, tok); + else + base_sz = new_num(ty->base->size, tok); + + ty->vla_size = new_lvar("", ty_ulong); + Node *expr = new_binary(ND_ASSIGN, new_var_node(ty->vla_size, tok), + new_binary(ND_MUL, ty->vla_len, base_sz, tok), + tok); + return new_binary(ND_COMMA, node, expr, tok); +} + +static Node *new_alloca(Node *sz) { + Node *node = new_unary(ND_FUNCALL, new_var_node(builtin_alloca, sz->tok), sz->tok); + node->func_ty = builtin_alloca->ty; + node->ty = builtin_alloca->ty->return_ty; + node->args = sz; + add_type(sz); + return node; +} + +// declaration = declspec (declarator ("=" expr)? ("," declarator ("=" expr)?)*)? ";" +static Node *declaration(Token **rest, Token *tok, Type *basety, VarAttr *attr) { + Node head = {}; + Node *cur = &head; + int i = 0; + + while (!equal(tok, ";")) { + if (i++ > 0) + tok = skip(tok, ","); + + Type *ty = declarator(&tok, tok, basety); + if (ty->kind == TY_VOID) + error_tok(tok, "variable declared void"); + if (!ty->name) + error_tok(ty->name_pos, "variable name omitted"); + + if (attr && attr->is_static) { + // static local variable + Obj *var = new_anon_gvar(ty); + push_scope(get_ident(ty->name))->var = var; + if (equal(tok, "=")) + gvar_initializer(&tok, tok->next, var); + continue; + } + + // Generate code for computing a VLA size. We need to do this + // even if ty is not VLA because ty may be a pointer to VLA + // (e.g. int (*foo)[n][m] where n and m are variables.) + cur = cur->next = new_unary(ND_EXPR_STMT, compute_vla_size(ty, tok), tok); + + if (ty->kind == TY_VLA) { + if (equal(tok, "=")) + error_tok(tok, "variable-sized object may not be initialized"); + + // Variable length arrays (VLAs) are translated to alloca() calls. + // For example, `int x[n+2]` is translated to `tmp = n + 2, + // x = alloca(tmp)`. + Obj *var = new_lvar(get_ident(ty->name), ty); + Token *tok = ty->name; + Node *expr = new_binary(ND_ASSIGN, new_vla_ptr(var, tok), + new_alloca(new_var_node(ty->vla_size, tok)), + tok); + + cur = cur->next = new_unary(ND_EXPR_STMT, expr, tok); + continue; + } + + Obj *var = new_lvar(get_ident(ty->name), ty); + if (attr && attr->align) + var->align = attr->align; + + if (equal(tok, "=")) { + Node *expr = lvar_initializer(&tok, tok->next, var); + cur = cur->next = new_unary(ND_EXPR_STMT, expr, tok); + } + + if (var->ty->size < 0) + error_tok(ty->name, "variable has incomplete type"); + if (var->ty->kind == TY_VOID) + error_tok(ty->name, "variable declared void"); + } + + Node *node = new_node(ND_BLOCK, tok); + node->body = head.next; + *rest = tok->next; + return node; +} + +static Token *skip_excess_element(Token *tok) { + if (equal(tok, "{")) { + tok = skip_excess_element(tok->next); + return skip(tok, "}"); + } + + assign(&tok, tok); + return tok; +} + +// string-initializer = string-literal +static void string_initializer(Token **rest, Token *tok, Initializer *init) { + if (init->is_flexible) + *init = *new_initializer(array_of(init->ty->base, tok->ty->array_len), false); + + int len = MIN(init->ty->array_len, tok->ty->array_len); + + switch (init->ty->base->size) { + case 1: { + char *str = tok->str; + for (int i = 0; i < len; i++) + init->children[i]->expr = new_num(str[i], tok); + break; + } + case 2: { + uint16_t *str = (uint16_t *)tok->str; + for (int i = 0; i < len; i++) + init->children[i]->expr = new_num(str[i], tok); + break; + } + case 4: { + uint32_t *str = (uint32_t *)tok->str; + for (int i = 0; i < len; i++) + init->children[i]->expr = new_num(str[i], tok); + break; + } + default: + unreachable(); + } + + *rest = tok->next; +} + +// array-designator = "[" const-expr "]" +// +// C99 added the designated initializer to the language, which allows +// programmers to move the "cursor" of an initializer to any element. +// The syntax looks like this: +// +// int x[10] = { 1, 2, [5]=3, 4, 5, 6, 7 }; +// +// `[5]` moves the cursor to the 5th element, so the 5th element of x +// is set to 3. Initialization then continues forward in order, so +// 6th, 7th, 8th and 9th elements are initialized with 4, 5, 6 and 7, +// respectively. Unspecified elements (in this case, 3rd and 4th +// elements) are initialized with zero. +// +// Nesting is allowed, so the following initializer is valid: +// +// int x[5][10] = { [5][8]=1, 2, 3 }; +// +// It sets x[5][8], x[5][9] and x[6][0] to 1, 2 and 3, respectively. +// +// Use `.fieldname` to move the cursor for a struct initializer. E.g. +// +// struct { int a, b, c; } x = { .c=5 }; +// +// The above initializer sets x.c to 5. +static void array_designator(Token **rest, Token *tok, Type *ty, int *begin, int *end) { + *begin = const_expr(&tok, tok->next); + if (*begin >= ty->array_len) + error_tok(tok, "array designator index exceeds array bounds"); + + if (equal(tok, "...")) { + *end = const_expr(&tok, tok->next); + if (*end >= ty->array_len) + error_tok(tok, "array designator index exceeds array bounds"); + if (*end < *begin) + error_tok(tok, "array designator range [%d, %d] is empty", *begin, *end); + } else { + *end = *begin; + } + + *rest = skip(tok, "]"); +} + +// struct-designator = "." ident +static Member *struct_designator(Token **rest, Token *tok, Type *ty) { + Token *start = tok; + tok = skip(tok, "."); + if (tok->kind != TK_IDENT) + error_tok(tok, "expected a field designator"); + + for (Member *mem = ty->members; mem; mem = mem->next) { + // Anonymous struct member + if (mem->ty->kind == TY_STRUCT && !mem->name) { + if (get_struct_member(mem->ty, tok)) { + *rest = start; + return mem; + } + continue; + } + + // Regular struct member + if (mem->name->len == tok->len && !strncmp(mem->name->loc, tok->loc, tok->len)) { + *rest = tok->next; + return mem; + } + } + + error_tok(tok, "struct has no such member"); +} + +// designation = ("[" const-expr "]" | "." ident)* "="? initializer +static void designation(Token **rest, Token *tok, Initializer *init) { + if (equal(tok, "[")) { + if (init->ty->kind != TY_ARRAY) + error_tok(tok, "array index in non-array initializer"); + + int begin, end; + array_designator(&tok, tok, init->ty, &begin, &end); + + Token *tok2; + for (int i = begin; i <= end; i++) + designation(&tok2, tok, init->children[i]); + array_initializer2(rest, tok2, init, begin + 1); + return; + } + + if (equal(tok, ".") && init->ty->kind == TY_STRUCT) { + Member *mem = struct_designator(&tok, tok, init->ty); + designation(&tok, tok, init->children[mem->idx]); + init->expr = NULL; + struct_initializer2(rest, tok, init, mem->next); + return; + } + + if (equal(tok, ".") && init->ty->kind == TY_UNION) { + Member *mem = struct_designator(&tok, tok, init->ty); + init->mem = mem; + designation(rest, tok, init->children[mem->idx]); + return; + } + + if (equal(tok, ".")) + error_tok(tok, "field name not in struct or union initializer"); + + if (equal(tok, "=")) + tok = tok->next; + initializer2(rest, tok, init); +} + +// An array length can be omitted if an array has an initializer +// (e.g. `int x[] = {1,2,3}`). If it's omitted, count the number +// of initializer elements. +static int count_array_init_elements(Token *tok, Type *ty) { + bool first = true; + Initializer *dummy = new_initializer(ty->base, true); + + int i = 0, max = 0; + + while (!consume_end(&tok, tok)) { + if (!first) + tok = skip(tok, ","); + first = false; + + if (equal(tok, "[")) { + i = const_expr(&tok, tok->next); + if (equal(tok, "...")) + i = const_expr(&tok, tok->next); + tok = skip(tok, "]"); + designation(&tok, tok, dummy); + } else { + initializer2(&tok, tok, dummy); + } + + i++; + max = MAX(max, i); + } + return max; +} + +// array-initializer1 = "{" initializer ("," initializer)* ","? "}" +static void array_initializer1(Token **rest, Token *tok, Initializer *init) { + tok = skip(tok, "{"); + + if (init->is_flexible) { + int len = count_array_init_elements(tok, init->ty); + *init = *new_initializer(array_of(init->ty->base, len), false); + } + + bool first = true; + + if (init->is_flexible) { + int len = count_array_init_elements(tok, init->ty); + *init = *new_initializer(array_of(init->ty->base, len), false); + } + + for (int i = 0; !consume_end(rest, tok); i++) { + if (!first) + tok = skip(tok, ","); + first = false; + + if (equal(tok, "[")) { + int begin, end; + array_designator(&tok, tok, init->ty, &begin, &end); + + Token *tok2; + for (int j = begin; j <= end; j++) + designation(&tok2, tok, init->children[j]); + tok = tok2; + i = end; + continue; + } + + if (i < init->ty->array_len) + initializer2(&tok, tok, init->children[i]); + else + tok = skip_excess_element(tok); + } +} + +// array-initializer2 = initializer ("," initializer)* +static void array_initializer2(Token **rest, Token *tok, Initializer *init, int i) { + if (init->is_flexible) { + int len = count_array_init_elements(tok, init->ty); + *init = *new_initializer(array_of(init->ty->base, len), false); + } + + for (; i < init->ty->array_len && !is_end(tok); i++) { + Token *start = tok; + if (i > 0) + tok = skip(tok, ","); + + if (equal(tok, "[") || equal(tok, ".")) { + *rest = start; + return; + } + + initializer2(&tok, tok, init->children[i]); + } + *rest = tok; +} + +// struct-initializer1 = "{" initializer ("," initializer)* ","? "}" +static void struct_initializer1(Token **rest, Token *tok, Initializer *init) { + tok = skip(tok, "{"); + + Member *mem = init->ty->members; + bool first = true; + + while (!consume_end(rest, tok)) { + if (!first) + tok = skip(tok, ","); + first = false; + + if (equal(tok, ".")) { + mem = struct_designator(&tok, tok, init->ty); + designation(&tok, tok, init->children[mem->idx]); + mem = mem->next; + continue; + } + + if (mem) { + initializer2(&tok, tok, init->children[mem->idx]); + mem = mem->next; + } else { + tok = skip_excess_element(tok); + } + } +} + +// struct-initializer2 = initializer ("," initializer)* +static void struct_initializer2(Token **rest, Token *tok, Initializer *init, Member *mem) { + bool first = true; + + for (; mem && !is_end(tok); mem = mem->next) { + Token *start = tok; + + if (!first) + tok = skip(tok, ","); + first = false; + + if (equal(tok, "[") || equal(tok, ".")) { + *rest = start; + return; + } + + initializer2(&tok, tok, init->children[mem->idx]); + } + *rest = tok; +} + +static void union_initializer(Token **rest, Token *tok, Initializer *init) { + // Unlike structs, union initializers take only one initializer, + // and that initializes the first union member by default. + // You can initialize other member using a designated initializer. + if (equal(tok, "{") && equal(tok->next, ".")) { + Member *mem = struct_designator(&tok, tok->next, init->ty); + init->mem = mem; + designation(&tok, tok, init->children[mem->idx]); + *rest = skip(tok, "}"); + return; + } + + init->mem = init->ty->members; + + if (equal(tok, "{")) { + initializer2(&tok, tok->next, init->children[0]); + consume(&tok, tok, ","); + *rest = skip(tok, "}"); + } else { + initializer2(rest, tok, init->children[0]); + } +} + +// initializer = string-initializer | array-initializer +// | struct-initializer | union-initializer +// | assign +static void initializer2(Token **rest, Token *tok, Initializer *init) { + if (init->ty->kind == TY_ARRAY && tok->kind == TK_STR) { + string_initializer(rest, tok, init); + return; + } + + if (init->ty->kind == TY_ARRAY) { + if (equal(tok, "{")) + array_initializer1(rest, tok, init); + else + array_initializer2(rest, tok, init, 0); + return; + } + + if (init->ty->kind == TY_STRUCT) { + if (equal(tok, "{")) { + struct_initializer1(rest, tok, init); + return; + } + + // A struct can be initialized with another struct. E.g. + // `struct T x = y;` where y is a variable of type `struct T`. + // Handle that case first. + Node *expr = assign(rest, tok); + add_type(expr); + if (expr->ty->kind == TY_STRUCT) { + init->expr = expr; + return; + } + + struct_initializer2(rest, tok, init, init->ty->members); + return; + } + + if (init->ty->kind == TY_UNION) { + union_initializer(rest, tok, init); + return; + } + + if (equal(tok, "{")) { + // An initializer for a scalar variable can be surrounded by + // braces. E.g. `int x = {3};`. Handle that case. + initializer2(&tok, tok->next, init); + *rest = skip(tok, "}"); + return; + } + + init->expr = assign(rest, tok); +} + +static Type *copy_struct_type(Type *ty) { + ty = copy_type(ty); + + Member head = {}; + Member *cur = &head; + for (Member *mem = ty->members; mem; mem = mem->next) { + Member *m = calloc(1, sizeof(Member)); + *m = *mem; + cur = cur->next = m; + } + + ty->members = head.next; + return ty; +} + +static Initializer *initializer(Token **rest, Token *tok, Type *ty, Type **new_ty) { + Initializer *init = new_initializer(ty, true); + initializer2(rest, tok, init); + + if ((ty->kind == TY_STRUCT || ty->kind == TY_UNION) && ty->is_flexible) { + ty = copy_struct_type(ty); + + Member *mem = ty->members; + while (mem->next) + mem = mem->next; + mem->ty = init->children[mem->idx]->ty; + ty->size += mem->ty->size; + + *new_ty = ty; + return init; + } + + *new_ty = init->ty; + return init; +} + +static Node *init_desg_expr(InitDesg *desg, Token *tok) { + if (desg->var) + return new_var_node(desg->var, tok); + + if (desg->member) { + Node *node = new_unary(ND_MEMBER, init_desg_expr(desg->next, tok), tok); + node->member = desg->member; + return node; + } + + Node *lhs = init_desg_expr(desg->next, tok); + Node *rhs = new_num(desg->idx, tok); + return new_unary(ND_DEREF, new_add(lhs, rhs, tok), tok); +} + +static Node *create_lvar_init(Initializer *init, Type *ty, InitDesg *desg, Token *tok) { + if (ty->kind == TY_ARRAY) { + Node *node = new_node(ND_NULL_EXPR, tok); + for (int i = 0; i < ty->array_len; i++) { + InitDesg desg2 = {desg, i}; + Node *rhs = create_lvar_init(init->children[i], ty->base, &desg2, tok); + node = new_binary(ND_COMMA, node, rhs, tok); + } + return node; + } + + if (ty->kind == TY_STRUCT && !init->expr) { + Node *node = new_node(ND_NULL_EXPR, tok); + + for (Member *mem = ty->members; mem; mem = mem->next) { + InitDesg desg2 = {desg, 0, mem}; + Node *rhs = create_lvar_init(init->children[mem->idx], mem->ty, &desg2, tok); + node = new_binary(ND_COMMA, node, rhs, tok); + } + return node; + } + + if (ty->kind == TY_UNION) { + Member *mem = init->mem ? init->mem : ty->members; + InitDesg desg2 = {desg, 0, mem}; + return create_lvar_init(init->children[mem->idx], mem->ty, &desg2, tok); + } + + if (!init->expr) + return new_node(ND_NULL_EXPR, tok); + + Node *lhs = init_desg_expr(desg, tok); + return new_binary(ND_ASSIGN, lhs, init->expr, tok); +} + +// A variable definition with an initializer is a shorthand notation +// for a variable definition followed by assignments. This function +// generates assignment expressions for an initializer. For example, +// `int x[2][2] = {{6, 7}, {8, 9}}` is converted to the following +// expressions: +// +// x[0][0] = 6; +// x[0][1] = 7; +// x[1][0] = 8; +// x[1][1] = 9; +static Node *lvar_initializer(Token **rest, Token *tok, Obj *var) { + Initializer *init = initializer(rest, tok, var->ty, &var->ty); + InitDesg desg = {NULL, 0, NULL, var}; + + // If a partial initializer list is given, the standard requires + // that unspecified elements are set to 0. Here, we simply + // zero-initialize the entire memory region of a variable before + // initializing it with user-supplied values. + Node *lhs = new_node(ND_MEMZERO, tok); + lhs->var = var; + + Node *rhs = create_lvar_init(init, var->ty, &desg, tok); + return new_binary(ND_COMMA, lhs, rhs, tok); +} + +static uint64_t read_buf(char *buf, int sz) { + if (sz == 1) + return *buf; + if (sz == 2) + return *(uint16_t *)buf; + if (sz == 4) + return *(uint32_t *)buf; + if (sz == 8) + return *(uint64_t *)buf; + unreachable(); +} + +static void write_buf(char *buf, uint64_t val, int sz) { + if (sz == 1) + *buf = val; + else if (sz == 2) + *(uint16_t *)buf = val; + else if (sz == 4) + *(uint32_t *)buf = val; + else if (sz == 8) + *(uint64_t *)buf = val; + else + unreachable(); +} + +static Relocation * +write_gvar_data(Relocation *cur, Initializer *init, Type *ty, char *buf, int offset) { + if (ty->kind == TY_ARRAY) { + int sz = ty->base->size; + for (int i = 0; i < ty->array_len; i++) + cur = write_gvar_data(cur, init->children[i], ty->base, buf, offset + sz * i); + return cur; + } + + if (ty->kind == TY_STRUCT) { + for (Member *mem = ty->members; mem; mem = mem->next) { + if (mem->is_bitfield) { + Node *expr = init->children[mem->idx]->expr; + if (!expr) + break; + + char *loc = buf + offset + mem->offset; + uint64_t oldval = read_buf(loc, mem->ty->size); + uint64_t newval = eval(expr); + uint64_t mask = (1L << mem->bit_width) - 1; + uint64_t combined = oldval | ((newval & mask) << mem->bit_offset); + write_buf(loc, combined, mem->ty->size); + } else { + cur = write_gvar_data(cur, init->children[mem->idx], mem->ty, buf, + offset + mem->offset); + } + } + return cur; + } + + if (ty->kind == TY_UNION) { + if (!init->mem) + return cur; + return write_gvar_data(cur, init->children[init->mem->idx], + init->mem->ty, buf, offset); + } + + if (!init->expr) + return cur; + + if (ty->kind == TY_FLOAT) { + *(float *)(buf + offset) = eval_double(init->expr); + return cur; + } + + if (ty->kind == TY_DOUBLE) { + *(double *)(buf + offset) = eval_double(init->expr); + return cur; + } + + char **label = NULL; + uint64_t val = eval2(init->expr, &label); + + if (!label) { + write_buf(buf + offset, val, ty->size); + return cur; + } + + Relocation *rel = calloc(1, sizeof(Relocation)); + rel->offset = offset; + rel->label = label; + rel->addend = val; + cur->next = rel; + return cur->next; +} + +// Initializers for global variables are evaluated at compile-time and +// embedded to .data section. This function serializes Initializer +// objects to a flat byte array. It is a compile error if an +// initializer list contains a non-constant expression. +static void gvar_initializer(Token **rest, Token *tok, Obj *var) { + Initializer *init = initializer(rest, tok, var->ty, &var->ty); + + Relocation head = {}; + char *buf = calloc(1, var->ty->size); + write_gvar_data(&head, init, var->ty, buf, 0); + var->init_data = buf; + var->rel = head.next; +} + +// Returns true if a given token represents a type. +static bool is_typename(Token *tok) { + static HashMap map; + + if (map.capacity == 0) { + static char *kw[] = { + "void", "_Bool", "char", "short", "int", "long", "struct", "union", + "typedef", "enum", "static", "extern", "_Alignas", "signed", "unsigned", + "const", "volatile", "auto", "register", "restrict", "__restrict", + "__restrict__", "_Noreturn", "float", "double", "typeof", "inline", + "_Thread_local", "__thread", "_Atomic", + }; + + for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++) + hashmap_put(&map, kw[i], (void *)1); + } + + return hashmap_get2(&map, tok->loc, tok->len) || find_typedef(tok); +} + +// asm-stmt = "asm" ("volatile" | "inline")* "(" string-literal ")" +static Node *asm_stmt(Token **rest, Token *tok) { + Node *node = new_node(ND_ASM, tok); + tok = tok->next; + + while (equal(tok, "volatile") || equal(tok, "inline")) + tok = tok->next; + + tok = skip(tok, "("); + if (tok->kind != TK_STR || tok->ty->base->kind != TY_CHAR) + error_tok(tok, "expected string literal"); + node->asm_str = tok->str; + *rest = skip(tok->next, ")"); + return node; +} + +// stmt = "return" expr? ";" +// | "if" "(" expr ")" stmt ("else" stmt)? +// | "switch" "(" expr ")" stmt +// | "case" const-expr ("..." const-expr)? ":" stmt +// | "default" ":" stmt +// | "for" "(" expr-stmt expr? ";" expr? ")" stmt +// | "while" "(" expr ")" stmt +// | "do" stmt "while" "(" expr ")" ";" +// | "asm" asm-stmt +// | "goto" (ident | "*" expr) ";" +// | "break" ";" +// | "continue" ";" +// | ident ":" stmt +// | "{" compound-stmt +// | expr-stmt +static Node *stmt(Token **rest, Token *tok) { + if (equal(tok, "return")) { + Node *node = new_node(ND_RETURN, tok); + if (consume(rest, tok->next, ";")) + return node; + + Node *exp = expr(&tok, tok->next); + *rest = skip(tok, ";"); + + add_type(exp); + Type *ty = current_fn->ty->return_ty; + if (ty->kind != TY_STRUCT && ty->kind != TY_UNION) + exp = new_cast(exp, current_fn->ty->return_ty); + + node->lhs = exp; + return node; + } + + if (equal(tok, "if")) { + Node *node = new_node(ND_IF, tok); + tok = skip(tok->next, "("); + node->cond = expr(&tok, tok); + tok = skip(tok, ")"); + node->then = stmt(&tok, tok); + if (equal(tok, "else")) + node->els = stmt(&tok, tok->next); + *rest = tok; + return node; + } + + if (equal(tok, "switch")) { + Node *node = new_node(ND_SWITCH, tok); + tok = skip(tok->next, "("); + node->cond = expr(&tok, tok); + tok = skip(tok, ")"); + + Node *sw = current_switch; + current_switch = node; + + char *brk = brk_label; + brk_label = node->brk_label = new_unique_name(); + + node->then = stmt(rest, tok); + + current_switch = sw; + brk_label = brk; + return node; + } + + if (equal(tok, "case")) { + if (!current_switch) + error_tok(tok, "stray case"); + + Node *node = new_node(ND_CASE, tok); + int begin = const_expr(&tok, tok->next); + int end; + + if (equal(tok, "...")) { + // [GNU] Case ranges, e.g. "case 1 ... 5:" + end = const_expr(&tok, tok->next); + if (end < begin) + error_tok(tok, "empty case range specified"); + } else { + end = begin; + } + + tok = skip(tok, ":"); + node->label = new_unique_name(); + node->lhs = stmt(rest, tok); + node->begin = begin; + node->end = end; + node->case_next = current_switch->case_next; + current_switch->case_next = node; + return node; + } + + if (equal(tok, "default")) { + if (!current_switch) + error_tok(tok, "stray default"); + + Node *node = new_node(ND_CASE, tok); + tok = skip(tok->next, ":"); + node->label = new_unique_name(); + node->lhs = stmt(rest, tok); + current_switch->default_case = node; + return node; + } + + if (equal(tok, "for")) { + Node *node = new_node(ND_FOR, tok); + tok = skip(tok->next, "("); + + enter_scope(); + + char *brk = brk_label; + char *cont = cont_label; + brk_label = node->brk_label = new_unique_name(); + cont_label = node->cont_label = new_unique_name(); + + if (is_typename(tok)) { + Type *basety = declspec(&tok, tok, NULL); + node->init = declaration(&tok, tok, basety, NULL); + } else { + node->init = expr_stmt(&tok, tok); + } + + if (!equal(tok, ";")) + node->cond = expr(&tok, tok); + tok = skip(tok, ";"); + + if (!equal(tok, ")")) + node->inc = expr(&tok, tok); + tok = skip(tok, ")"); + + node->then = stmt(rest, tok); + + leave_scope(); + brk_label = brk; + cont_label = cont; + return node; + } + + if (equal(tok, "while")) { + Node *node = new_node(ND_FOR, tok); + tok = skip(tok->next, "("); + node->cond = expr(&tok, tok); + tok = skip(tok, ")"); + + char *brk = brk_label; + char *cont = cont_label; + brk_label = node->brk_label = new_unique_name(); + cont_label = node->cont_label = new_unique_name(); + + node->then = stmt(rest, tok); + + brk_label = brk; + cont_label = cont; + return node; + } + + if (equal(tok, "do")) { + Node *node = new_node(ND_DO, tok); + + char *brk = brk_label; + char *cont = cont_label; + brk_label = node->brk_label = new_unique_name(); + cont_label = node->cont_label = new_unique_name(); + + node->then = stmt(&tok, tok->next); + + brk_label = brk; + cont_label = cont; + + tok = skip(tok, "while"); + tok = skip(tok, "("); + node->cond = expr(&tok, tok); + tok = skip(tok, ")"); + *rest = skip(tok, ";"); + return node; + } + + if (equal(tok, "asm")) + return asm_stmt(rest, tok); + + if (equal(tok, "goto")) { + if (equal(tok->next, "*")) { + // [GNU] `goto *ptr` jumps to the address specified by `ptr`. + Node *node = new_node(ND_GOTO_EXPR, tok); + node->lhs = expr(&tok, tok->next->next); + *rest = skip(tok, ";"); + return node; + } + + Node *node = new_node(ND_GOTO, tok); + node->label = get_ident(tok->next); + node->goto_next = gotos; + gotos = node; + *rest = skip(tok->next->next, ";"); + return node; + } + + if (equal(tok, "break")) { + if (!brk_label) + error_tok(tok, "stray break"); + Node *node = new_node(ND_GOTO, tok); + node->unique_label = brk_label; + *rest = skip(tok->next, ";"); + return node; + } + + if (equal(tok, "continue")) { + if (!cont_label) + error_tok(tok, "stray continue"); + Node *node = new_node(ND_GOTO, tok); + node->unique_label = cont_label; + *rest = skip(tok->next, ";"); + return node; + } + + if (tok->kind == TK_IDENT && equal(tok->next, ":")) { + Node *node = new_node(ND_LABEL, tok); + node->label = strndup(tok->loc, tok->len); + node->unique_label = new_unique_name(); + node->lhs = stmt(rest, tok->next->next); + node->goto_next = labels; + labels = node; + return node; + } + + if (equal(tok, "{")) + return compound_stmt(rest, tok->next); + + return expr_stmt(rest, tok); +} + +// compound-stmt = (typedef | declaration | stmt)* "}" +static Node *compound_stmt(Token **rest, Token *tok) { + Node *node = new_node(ND_BLOCK, tok); + Node head = {}; + Node *cur = &head; + + enter_scope(); + + while (!equal(tok, "}")) { + if (is_typename(tok) && !equal(tok->next, ":")) { + VarAttr attr = {}; + Type *basety = declspec(&tok, tok, &attr); + + if (attr.is_typedef) { + tok = parse_typedef(tok, basety); + continue; + } + + if (is_function(tok)) { + tok = function(tok, basety, &attr); + continue; + } + + if (attr.is_extern) { + tok = global_variable(tok, basety, &attr); + continue; + } + + cur = cur->next = declaration(&tok, tok, basety, &attr); + } else { + cur = cur->next = stmt(&tok, tok); + } + add_type(cur); + } + + leave_scope(); + + node->body = head.next; + *rest = tok->next; + return node; +} + +// expr-stmt = expr? ";" +static Node *expr_stmt(Token **rest, Token *tok) { + if (equal(tok, ";")) { + *rest = tok->next; + return new_node(ND_BLOCK, tok); + } + + Node *node = new_node(ND_EXPR_STMT, tok); + node->lhs = expr(&tok, tok); + *rest = skip(tok, ";"); + return node; +} + +// expr = assign ("," expr)? +static Node *expr(Token **rest, Token *tok) { + Node *node = assign(&tok, tok); + + if (equal(tok, ",")) + return new_binary(ND_COMMA, node, expr(rest, tok->next), tok); + + *rest = tok; + return node; +} + +static int64_t eval(Node *node) { + return eval2(node, NULL); +} + +// Evaluate a given node as a constant expression. +// +// A constant expression is either just a number or ptr+n where ptr +// is a pointer to a global variable and n is a postiive/negative +// number. The latter form is accepted only as an initialization +// expression for a global variable. +static int64_t eval2(Node *node, char ***label) { + add_type(node); + + if (is_flonum(node->ty)) + return eval_double(node); + + switch (node->kind) { + case ND_ADD: + return eval2(node->lhs, label) + eval(node->rhs); + case ND_SUB: + return eval2(node->lhs, label) - eval(node->rhs); + case ND_MUL: + return eval(node->lhs) * eval(node->rhs); + case ND_DIV: + if (node->ty->is_unsigned) + return (uint64_t)eval(node->lhs) / eval(node->rhs); + return eval(node->lhs) / eval(node->rhs); + case ND_NEG: + return -eval(node->lhs); + case ND_MOD: + if (node->ty->is_unsigned) + return (uint64_t)eval(node->lhs) % eval(node->rhs); + return eval(node->lhs) % eval(node->rhs); + case ND_BITAND: + return eval(node->lhs) & eval(node->rhs); + case ND_BITOR: + return eval(node->lhs) | eval(node->rhs); + case ND_BITXOR: + return eval(node->lhs) ^ eval(node->rhs); + case ND_SHL: + return eval(node->lhs) << eval(node->rhs); + case ND_SHR: + if (node->ty->is_unsigned && node->ty->size == 8) + return (uint64_t)eval(node->lhs) >> eval(node->rhs); + return eval(node->lhs) >> eval(node->rhs); + case ND_EQ: + return eval(node->lhs) == eval(node->rhs); + case ND_NE: + return eval(node->lhs) != eval(node->rhs); + case ND_LT: + if (node->lhs->ty->is_unsigned) + return (uint64_t)eval(node->lhs) < eval(node->rhs); + return eval(node->lhs) < eval(node->rhs); + case ND_LE: + if (node->lhs->ty->is_unsigned) + return (uint64_t)eval(node->lhs) <= eval(node->rhs); + return eval(node->lhs) <= eval(node->rhs); + case ND_COND: + return eval(node->cond) ? eval2(node->then, label) : eval2(node->els, label); + case ND_COMMA: + return eval2(node->rhs, label); + case ND_NOT: + return !eval(node->lhs); + case ND_BITNOT: + return ~eval(node->lhs); + case ND_LOGAND: + return eval(node->lhs) && eval(node->rhs); + case ND_LOGOR: + return eval(node->lhs) || eval(node->rhs); + case ND_CAST: { + int64_t val = eval2(node->lhs, label); + if (is_integer(node->ty)) { + switch (node->ty->size) { + case 1: return node->ty->is_unsigned ? (uint8_t)val : (int8_t)val; + case 2: return node->ty->is_unsigned ? (uint16_t)val : (int16_t)val; + case 4: return node->ty->is_unsigned ? (uint32_t)val : (int32_t)val; + } + } + return val; + } + case ND_ADDR: + return eval_rval(node->lhs, label); + case ND_LABEL_VAL: + *label = &node->unique_label; + return 0; + case ND_MEMBER: + if (!label) + error_tok(node->tok, "not a compile-time constant"); + if (node->ty->kind != TY_ARRAY) + error_tok(node->tok, "invalid initializer"); + return eval_rval(node->lhs, label) + node->member->offset; + case ND_VAR: + if (!label) + error_tok(node->tok, "not a compile-time constant"); + if (node->var->ty->kind != TY_ARRAY && node->var->ty->kind != TY_FUNC) + error_tok(node->tok, "invalid initializer"); + *label = &node->var->name; + return 0; + case ND_NUM: + return node->val; + } + + error_tok(node->tok, "not a compile-time constant"); +} + +static int64_t eval_rval(Node *node, char ***label) { + switch (node->kind) { + case ND_VAR: + if (node->var->is_local) + error_tok(node->tok, "not a compile-time constant"); + *label = &node->var->name; + return 0; + case ND_DEREF: + return eval2(node->lhs, label); + case ND_MEMBER: + return eval_rval(node->lhs, label) + node->member->offset; + } + + error_tok(node->tok, "invalid initializer"); +} + +static bool is_const_expr(Node *node) { + add_type(node); + + switch (node->kind) { + case ND_ADD: + case ND_SUB: + case ND_MUL: + case ND_DIV: + case ND_BITAND: + case ND_BITOR: + case ND_BITXOR: + case ND_SHL: + case ND_SHR: + case ND_EQ: + case ND_NE: + case ND_LT: + case ND_LE: + case ND_LOGAND: + case ND_LOGOR: + return is_const_expr(node->lhs) && is_const_expr(node->rhs); + case ND_COND: + if (!is_const_expr(node->cond)) + return false; + return is_const_expr(eval(node->cond) ? node->then : node->els); + case ND_COMMA: + return is_const_expr(node->rhs); + case ND_NEG: + case ND_NOT: + case ND_BITNOT: + case ND_CAST: + return is_const_expr(node->lhs); + case ND_NUM: + return true; + } + + return false; +} + +int64_t const_expr(Token **rest, Token *tok) { + Node *node = conditional(rest, tok); + return eval(node); +} + +static double eval_double(Node *node) { + add_type(node); + + if (is_integer(node->ty)) { + if (node->ty->is_unsigned) + return (unsigned long)eval(node); + return eval(node); + } + + switch (node->kind) { + case ND_ADD: + return eval_double(node->lhs) + eval_double(node->rhs); + case ND_SUB: + return eval_double(node->lhs) - eval_double(node->rhs); + case ND_MUL: + return eval_double(node->lhs) * eval_double(node->rhs); + case ND_DIV: + return eval_double(node->lhs) / eval_double(node->rhs); + case ND_NEG: + return -eval_double(node->lhs); + case ND_COND: + return eval_double(node->cond) ? eval_double(node->then) : eval_double(node->els); + case ND_COMMA: + return eval_double(node->rhs); + case ND_CAST: + if (is_flonum(node->lhs->ty)) + return eval_double(node->lhs); + return eval(node->lhs); + case ND_NUM: + return node->fval; + } + + error_tok(node->tok, "not a compile-time constant"); +} + +// Convert op= operators to expressions containing an assignment. +// +// In general, `A op= C` is converted to ``tmp = &A, *tmp = *tmp op B`. +// However, if a given expression is of form `A.x op= C`, the input is +// converted to `tmp = &A, (*tmp).x = (*tmp).x op C` to handle assignments +// to bitfields. +static Node *to_assign(Node *binary) { + add_type(binary->lhs); + add_type(binary->rhs); + Token *tok = binary->tok; + + // Convert `A.x op= C` to `tmp = &A, (*tmp).x = (*tmp).x op C`. + if (binary->lhs->kind == ND_MEMBER) { + Obj *var = new_lvar("", pointer_to(binary->lhs->lhs->ty)); + + Node *expr1 = new_binary(ND_ASSIGN, new_var_node(var, tok), + new_unary(ND_ADDR, binary->lhs->lhs, tok), tok); + + Node *expr2 = new_unary(ND_MEMBER, + new_unary(ND_DEREF, new_var_node(var, tok), tok), + tok); + expr2->member = binary->lhs->member; + + Node *expr3 = new_unary(ND_MEMBER, + new_unary(ND_DEREF, new_var_node(var, tok), tok), + tok); + expr3->member = binary->lhs->member; + + Node *expr4 = new_binary(ND_ASSIGN, expr2, + new_binary(binary->kind, expr3, binary->rhs, tok), + tok); + + return new_binary(ND_COMMA, expr1, expr4, tok); + } + + // If A is an atomic type, Convert `A op= B` to + // + // ({ + // T1 *addr = &A; T2 val = (B); T1 old = *addr; T1 new; + // do { + // new = old op val; + // } while (!atomic_compare_exchange_strong(addr, &old, new)); + // new; + // }) + if (binary->lhs->ty->is_atomic) { + Node head = {}; + Node *cur = &head; + + Obj *addr = new_lvar("", pointer_to(binary->lhs->ty)); + Obj *val = new_lvar("", binary->rhs->ty); + Obj *old = new_lvar("", binary->lhs->ty); + Obj *new = new_lvar("", binary->lhs->ty); + + cur = cur->next = + new_unary(ND_EXPR_STMT, + new_binary(ND_ASSIGN, new_var_node(addr, tok), + new_unary(ND_ADDR, binary->lhs, tok), tok), + tok); + + cur = cur->next = + new_unary(ND_EXPR_STMT, + new_binary(ND_ASSIGN, new_var_node(val, tok), binary->rhs, tok), + tok); + + cur = cur->next = + new_unary(ND_EXPR_STMT, + new_binary(ND_ASSIGN, new_var_node(old, tok), + new_unary(ND_DEREF, new_var_node(addr, tok), tok), tok), + tok); + + Node *loop = new_node(ND_DO, tok); + loop->brk_label = new_unique_name(); + loop->cont_label = new_unique_name(); + + Node *body = new_binary(ND_ASSIGN, + new_var_node(new, tok), + new_binary(binary->kind, new_var_node(old, tok), + new_var_node(val, tok), tok), + tok); + + loop->then = new_node(ND_BLOCK, tok); + loop->then->body = new_unary(ND_EXPR_STMT, body, tok); + + Node *cas = new_node(ND_CAS, tok); + cas->cas_addr = new_var_node(addr, tok); + cas->cas_old = new_unary(ND_ADDR, new_var_node(old, tok), tok); + cas->cas_new = new_var_node(new, tok); + loop->cond = new_unary(ND_NOT, cas, tok); + + cur = cur->next = loop; + cur = cur->next = new_unary(ND_EXPR_STMT, new_var_node(new, tok), tok); + + Node *node = new_node(ND_STMT_EXPR, tok); + node->body = head.next; + return node; + } + + // Convert `A op= B` to ``tmp = &A, *tmp = *tmp op B`. + Obj *var = new_lvar("", pointer_to(binary->lhs->ty)); + + Node *expr1 = new_binary(ND_ASSIGN, new_var_node(var, tok), + new_unary(ND_ADDR, binary->lhs, tok), tok); + + Node *expr2 = + new_binary(ND_ASSIGN, + new_unary(ND_DEREF, new_var_node(var, tok), tok), + new_binary(binary->kind, + new_unary(ND_DEREF, new_var_node(var, tok), tok), + binary->rhs, + tok), + tok); + + return new_binary(ND_COMMA, expr1, expr2, tok); +} + +// assign = conditional (assign-op assign)? +// assign-op = "=" | "+=" | "-=" | "*=" | "/=" | "%=" | "&=" | "|=" | "^=" +// | "<<=" | ">>=" +static Node *assign(Token **rest, Token *tok) { + Node *node = conditional(&tok, tok); + + if (equal(tok, "=")) + return new_binary(ND_ASSIGN, node, assign(rest, tok->next), tok); + + if (equal(tok, "+=")) + return to_assign(new_add(node, assign(rest, tok->next), tok)); + + if (equal(tok, "-=")) + return to_assign(new_sub(node, assign(rest, tok->next), tok)); + + if (equal(tok, "*=")) + return to_assign(new_binary(ND_MUL, node, assign(rest, tok->next), tok)); + + if (equal(tok, "/=")) + return to_assign(new_binary(ND_DIV, node, assign(rest, tok->next), tok)); + + if (equal(tok, "%=")) + return to_assign(new_binary(ND_MOD, node, assign(rest, tok->next), tok)); + + if (equal(tok, "&=")) + return to_assign(new_binary(ND_BITAND, node, assign(rest, tok->next), tok)); + + if (equal(tok, "|=")) + return to_assign(new_binary(ND_BITOR, node, assign(rest, tok->next), tok)); + + if (equal(tok, "^=")) + return to_assign(new_binary(ND_BITXOR, node, assign(rest, tok->next), tok)); + + if (equal(tok, "<<=")) + return to_assign(new_binary(ND_SHL, node, assign(rest, tok->next), tok)); + + if (equal(tok, ">>=")) + return to_assign(new_binary(ND_SHR, node, assign(rest, tok->next), tok)); + + *rest = tok; + return node; +} + +// conditional = logor ("?" expr? ":" conditional)? +static Node *conditional(Token **rest, Token *tok) { + Node *cond = logor(&tok, tok); + + if (!equal(tok, "?")) { + *rest = tok; + return cond; + } + + if (equal(tok->next, ":")) { + // [GNU] Compile `a ?: b` as `tmp = a, tmp ? tmp : b`. + add_type(cond); + Obj *var = new_lvar("", cond->ty); + Node *lhs = new_binary(ND_ASSIGN, new_var_node(var, tok), cond, tok); + Node *rhs = new_node(ND_COND, tok); + rhs->cond = new_var_node(var, tok); + rhs->then = new_var_node(var, tok); + rhs->els = conditional(rest, tok->next->next); + return new_binary(ND_COMMA, lhs, rhs, tok); + } + + Node *node = new_node(ND_COND, tok); + node->cond = cond; + node->then = expr(&tok, tok->next); + tok = skip(tok, ":"); + node->els = conditional(rest, tok); + return node; +} + +// logor = logand ("||" logand)* +static Node *logor(Token **rest, Token *tok) { + Node *node = logand(&tok, tok); + while (equal(tok, "||")) { + Token *start = tok; + node = new_binary(ND_LOGOR, node, logand(&tok, tok->next), start); + } + *rest = tok; + return node; +} + +// logand = bitor ("&&" bitor)* +static Node *logand(Token **rest, Token *tok) { + Node *node = bitor(&tok, tok); + while (equal(tok, "&&")) { + Token *start = tok; + node = new_binary(ND_LOGAND, node, bitor(&tok, tok->next), start); + } + *rest = tok; + return node; +} + +// bitor = bitxor ("|" bitxor)* +static Node *bitor(Token **rest, Token *tok) { + Node *node = bitxor(&tok, tok); + while (equal(tok, "|")) { + Token *start = tok; + node = new_binary(ND_BITOR, node, bitxor(&tok, tok->next), start); + } + *rest = tok; + return node; +} + +// bitxor = bitand ("^" bitand)* +static Node *bitxor(Token **rest, Token *tok) { + Node *node = bitand(&tok, tok); + while (equal(tok, "^")) { + Token *start = tok; + node = new_binary(ND_BITXOR, node, bitand(&tok, tok->next), start); + } + *rest = tok; + return node; +} + +// bitand = equality ("&" equality)* +static Node *bitand(Token **rest, Token *tok) { + Node *node = equality(&tok, tok); + while (equal(tok, "&")) { + Token *start = tok; + node = new_binary(ND_BITAND, node, equality(&tok, tok->next), start); + } + *rest = tok; + return node; +} + +// equality = relational ("==" relational | "!=" relational)* +static Node *equality(Token **rest, Token *tok) { + Node *node = relational(&tok, tok); + + for (;;) { + Token *start = tok; + + if (equal(tok, "==")) { + node = new_binary(ND_EQ, node, relational(&tok, tok->next), start); + continue; + } + + if (equal(tok, "!=")) { + node = new_binary(ND_NE, node, relational(&tok, tok->next), start); + continue; + } + + *rest = tok; + return node; + } +} + +// relational = shift ("<" shift | "<=" shift | ">" shift | ">=" shift)* +static Node *relational(Token **rest, Token *tok) { + Node *node = shift(&tok, tok); + + for (;;) { + Token *start = tok; + + if (equal(tok, "<")) { + node = new_binary(ND_LT, node, shift(&tok, tok->next), start); + continue; + } + + if (equal(tok, "<=")) { + node = new_binary(ND_LE, node, shift(&tok, tok->next), start); + continue; + } + + if (equal(tok, ">")) { + node = new_binary(ND_LT, shift(&tok, tok->next), node, start); + continue; + } + + if (equal(tok, ">=")) { + node = new_binary(ND_LE, shift(&tok, tok->next), node, start); + continue; + } + + *rest = tok; + return node; + } +} + +// shift = add ("<<" add | ">>" add)* +static Node *shift(Token **rest, Token *tok) { + Node *node = add(&tok, tok); + + for (;;) { + Token *start = tok; + + if (equal(tok, "<<")) { + node = new_binary(ND_SHL, node, add(&tok, tok->next), start); + continue; + } + + if (equal(tok, ">>")) { + node = new_binary(ND_SHR, node, add(&tok, tok->next), start); + continue; + } + + *rest = tok; + return node; + } +} + +// In C, `+` operator is overloaded to perform the pointer arithmetic. +// If p is a pointer, p+n adds not n but sizeof(*p)*n to the value of p, +// so that p+n points to the location n elements (not bytes) ahead of p. +// In other words, we need to scale an integer value before adding to a +// pointer value. This function takes care of the scaling. +static Node *new_add(Node *lhs, Node *rhs, Token *tok) { + add_type(lhs); + add_type(rhs); + + // num + num + if (is_numeric(lhs->ty) && is_numeric(rhs->ty)) + return new_binary(ND_ADD, lhs, rhs, tok); + + if (lhs->ty->base && rhs->ty->base) + error_tok(tok, "invalid operands"); + + // Canonicalize `num + ptr` to `ptr + num`. + if (!lhs->ty->base && rhs->ty->base) { + Node *tmp = lhs; + lhs = rhs; + rhs = tmp; + } + + // VLA + num + if (lhs->ty->base->kind == TY_VLA) { + rhs = new_binary(ND_MUL, rhs, new_var_node(lhs->ty->base->vla_size, tok), tok); + return new_binary(ND_ADD, lhs, rhs, tok); + } + + // ptr + num + rhs = new_binary(ND_MUL, rhs, new_long(lhs->ty->base->size, tok), tok); + return new_binary(ND_ADD, lhs, rhs, tok); +} + +// Like `+`, `-` is overloaded for the pointer type. +static Node *new_sub(Node *lhs, Node *rhs, Token *tok) { + add_type(lhs); + add_type(rhs); + + // num - num + if (is_numeric(lhs->ty) && is_numeric(rhs->ty)) + return new_binary(ND_SUB, lhs, rhs, tok); + + // VLA + num + if (lhs->ty->base->kind == TY_VLA) { + rhs = new_binary(ND_MUL, rhs, new_var_node(lhs->ty->base->vla_size, tok), tok); + add_type(rhs); + Node *node = new_binary(ND_SUB, lhs, rhs, tok); + node->ty = lhs->ty; + return node; + } + + // ptr - num + if (lhs->ty->base && is_integer(rhs->ty)) { + rhs = new_binary(ND_MUL, rhs, new_long(lhs->ty->base->size, tok), tok); + add_type(rhs); + Node *node = new_binary(ND_SUB, lhs, rhs, tok); + node->ty = lhs->ty; + return node; + } + + // ptr - ptr, which returns how many elements are between the two. + if (lhs->ty->base && rhs->ty->base) { + Node *node = new_binary(ND_SUB, lhs, rhs, tok); + node->ty = ty_long; + return new_binary(ND_DIV, node, new_num(lhs->ty->base->size, tok), tok); + } + + error_tok(tok, "invalid operands"); +} + +// add = mul ("+" mul | "-" mul)* +static Node *add(Token **rest, Token *tok) { + Node *node = mul(&tok, tok); + + for (;;) { + Token *start = tok; + + if (equal(tok, "+")) { + node = new_add(node, mul(&tok, tok->next), start); + continue; + } + + if (equal(tok, "-")) { + node = new_sub(node, mul(&tok, tok->next), start); + continue; + } + + *rest = tok; + return node; + } +} + +// mul = cast ("*" cast | "/" cast | "%" cast)* +static Node *mul(Token **rest, Token *tok) { + Node *node = cast(&tok, tok); + + for (;;) { + Token *start = tok; + + if (equal(tok, "*")) { + node = new_binary(ND_MUL, node, cast(&tok, tok->next), start); + continue; + } + + if (equal(tok, "/")) { + node = new_binary(ND_DIV, node, cast(&tok, tok->next), start); + continue; + } + + if (equal(tok, "%")) { + node = new_binary(ND_MOD, node, cast(&tok, tok->next), start); + continue; + } + + *rest = tok; + return node; + } +} + +// cast = "(" type-name ")" cast | unary +static Node *cast(Token **rest, Token *tok) { + if (equal(tok, "(") && is_typename(tok->next)) { + Token *start = tok; + Type *ty = typename(&tok, tok->next); + tok = skip(tok, ")"); + + // compound literal + if (equal(tok, "{")) + return unary(rest, start); + + // type cast + Node *node = new_cast(cast(rest, tok), ty); + node->tok = start; + return node; + } + + return unary(rest, tok); +} + +// unary = ("+" | "-" | "*" | "&" | "!" | "~") cast +// | ("++" | "--") unary +// | "&&" ident +// | postfix +static Node *unary(Token **rest, Token *tok) { + if (equal(tok, "+")) + return cast(rest, tok->next); + + if (equal(tok, "-")) + return new_unary(ND_NEG, cast(rest, tok->next), tok); + + if (equal(tok, "&")) { + Node *lhs = cast(rest, tok->next); + add_type(lhs); + if (lhs->kind == ND_MEMBER && lhs->member->is_bitfield) + error_tok(tok, "cannot take address of bitfield"); + return new_unary(ND_ADDR, lhs, tok); + } + + if (equal(tok, "*")) { + // [https://www.sigbus.info/n1570#6.5.3.2p4] This is an oddity + // in the C spec, but dereferencing a function shouldn't do + // anything. If foo is a function, `*foo`, `**foo` or `*****foo` + // are all equivalent to just `foo`. + Node *node = cast(rest, tok->next); + add_type(node); + if (node->ty->kind == TY_FUNC) + return node; + return new_unary(ND_DEREF, node, tok); + } + + if (equal(tok, "!")) + return new_unary(ND_NOT, cast(rest, tok->next), tok); + + if (equal(tok, "~")) + return new_unary(ND_BITNOT, cast(rest, tok->next), tok); + + // Read ++i as i+=1 + if (equal(tok, "++")) + return to_assign(new_add(unary(rest, tok->next), new_num(1, tok), tok)); + + // Read --i as i-=1 + if (equal(tok, "--")) + return to_assign(new_sub(unary(rest, tok->next), new_num(1, tok), tok)); + + // [GNU] labels-as-values + if (equal(tok, "&&")) { + Node *node = new_node(ND_LABEL_VAL, tok); + node->label = get_ident(tok->next); + node->goto_next = gotos; + gotos = node; + *rest = tok->next->next; + return node; + } + + return postfix(rest, tok); +} + +// struct-members = (declspec declarator ("," declarator)* ";")* +static void struct_members(Token **rest, Token *tok, Type *ty) { + Member head = {}; + Member *cur = &head; + int idx = 0; + + while (!equal(tok, "}")) { + VarAttr attr = {}; + Type *basety = declspec(&tok, tok, &attr); + bool first = true; + + // Anonymous struct member + if ((basety->kind == TY_STRUCT || basety->kind == TY_UNION) && + consume(&tok, tok, ";")) { + Member *mem = calloc(1, sizeof(Member)); + mem->ty = basety; + mem->idx = idx++; + mem->align = attr.align ? attr.align : mem->ty->align; + cur = cur->next = mem; + continue; + } + + // Regular struct members + while (!consume(&tok, tok, ";")) { + if (!first) + tok = skip(tok, ","); + first = false; + + Member *mem = calloc(1, sizeof(Member)); + mem->ty = declarator(&tok, tok, basety); + mem->name = mem->ty->name; + mem->idx = idx++; + mem->align = attr.align ? attr.align : mem->ty->align; + + if (consume(&tok, tok, ":")) { + mem->is_bitfield = true; + mem->bit_width = const_expr(&tok, tok); + } + + cur = cur->next = mem; + } + } + + // If the last element is an array of incomplete type, it's + // called a "flexible array member". It should behave as if + // if were a zero-sized array. + if (cur != &head && cur->ty->kind == TY_ARRAY && cur->ty->array_len < 0) { + cur->ty = array_of(cur->ty->base, 0); + ty->is_flexible = true; + } + + *rest = tok->next; + ty->members = head.next; +} + +// attribute = ("__attribute__" "(" "(" "packed" ")" ")")* +static Token *attribute_list(Token *tok, Type *ty) { + while (consume(&tok, tok, "__attribute__")) { + tok = skip(tok, "("); + tok = skip(tok, "("); + + bool first = true; + + while (!consume(&tok, tok, ")")) { + if (!first) + tok = skip(tok, ","); + first = false; + + if (consume(&tok, tok, "packed")) { + ty->is_packed = true; + continue; + } + + if (consume(&tok, tok, "aligned")) { + tok = skip(tok, "("); + ty->align = const_expr(&tok, tok); + tok = skip(tok, ")"); + continue; + } + + error_tok(tok, "unknown attribute"); + } + + tok = skip(tok, ")"); + } + + return tok; +} + +// struct-union-decl = attribute? ident? ("{" struct-members)? +static Type *struct_union_decl(Token **rest, Token *tok) { + Type *ty = struct_type(); + tok = attribute_list(tok, ty); + + // Read a tag. + Token *tag = NULL; + if (tok->kind == TK_IDENT) { + tag = tok; + tok = tok->next; + } + + if (tag && !equal(tok, "{")) { + *rest = tok; + + Type *ty2 = find_tag(tag); + if (ty2) + return ty2; + + ty->size = -1; + push_tag_scope(tag, ty); + return ty; + } + + tok = skip(tok, "{"); + + // Construct a struct object. + struct_members(&tok, tok, ty); + *rest = attribute_list(tok, ty); + + if (tag) { + // If this is a redefinition, overwrite a previous type. + // Otherwise, register the struct type. + Type *ty2 = hashmap_get2(&scope->tags, tag->loc, tag->len); + if (ty2) { + *ty2 = *ty; + return ty2; + } + + push_tag_scope(tag, ty); + } + + return ty; +} + +// struct-decl = struct-union-decl +static Type *struct_decl(Token **rest, Token *tok) { + Type *ty = struct_union_decl(rest, tok); + ty->kind = TY_STRUCT; + + if (ty->size < 0) + return ty; + + // Assign offsets within the struct to members. + int bits = 0; + + for (Member *mem = ty->members; mem; mem = mem->next) { + if (mem->is_bitfield && mem->bit_width == 0) { + // Zero-width anonymous bitfield has a special meaning. + // It affects only alignment. + bits = align_to(bits, mem->ty->size * 8); + } else if (mem->is_bitfield) { + int sz = mem->ty->size; + if (bits / (sz * 8) != (bits + mem->bit_width - 1) / (sz * 8)) + bits = align_to(bits, sz * 8); + + mem->offset = align_down(bits / 8, sz); + mem->bit_offset = bits % (sz * 8); + bits += mem->bit_width; + } else { + if (!ty->is_packed) + bits = align_to(bits, mem->align * 8); + mem->offset = bits / 8; + bits += mem->ty->size * 8; + } + + if (!ty->is_packed && ty->align < mem->align) + ty->align = mem->align; + } + + ty->size = align_to(bits, ty->align * 8) / 8; + return ty; +} + +// union-decl = struct-union-decl +static Type *union_decl(Token **rest, Token *tok) { + Type *ty = struct_union_decl(rest, tok); + ty->kind = TY_UNION; + + if (ty->size < 0) + return ty; + + // If union, we don't have to assign offsets because they + // are already initialized to zero. We need to compute the + // alignment and the size though. + for (Member *mem = ty->members; mem; mem = mem->next) { + if (ty->align < mem->align) + ty->align = mem->align; + if (ty->size < mem->ty->size) + ty->size = mem->ty->size; + } + ty->size = align_to(ty->size, ty->align); + return ty; +} + +// Find a struct member by name. +static Member *get_struct_member(Type *ty, Token *tok) { + for (Member *mem = ty->members; mem; mem = mem->next) { + // Anonymous struct member + if ((mem->ty->kind == TY_STRUCT || mem->ty->kind == TY_UNION) && + !mem->name) { + if (get_struct_member(mem->ty, tok)) + return mem; + continue; + } + + // Regular struct member + if (mem->name->len == tok->len && + !strncmp(mem->name->loc, tok->loc, tok->len)) + return mem; + } + return NULL; +} + +// Create a node representing a struct member access, such as foo.bar +// where foo is a struct and bar is a member name. +// +// C has a feature called "anonymous struct" which allows a struct to +// have another unnamed struct as a member like this: +// +// struct { struct { int a; }; int b; } x; +// +// The members of an anonymous struct belong to the outer struct's +// member namespace. Therefore, in the above example, you can access +// member "a" of the anonymous struct as "x.a". +// +// This function takes care of anonymous structs. +static Node *struct_ref(Node *node, Token *tok) { + add_type(node); + if (node->ty->kind != TY_STRUCT && node->ty->kind != TY_UNION) + error_tok(node->tok, "not a struct nor a union"); + + Type *ty = node->ty; + + for (;;) { + Member *mem = get_struct_member(ty, tok); + if (!mem) + error_tok(tok, "no such member"); + node = new_unary(ND_MEMBER, node, tok); + node->member = mem; + if (mem->name) + break; + ty = mem->ty; + } + return node; +} + +// Convert A++ to `(typeof A)((A += 1) - 1)` +static Node *new_inc_dec(Node *node, Token *tok, int addend) { + add_type(node); + return new_cast(new_add(to_assign(new_add(node, new_num(addend, tok), tok)), + new_num(-addend, tok), tok), + node->ty); +} + +// postfix = "(" type-name ")" "{" initializer-list "}" +// = ident "(" func-args ")" postfix-tail* +// | primary postfix-tail* +// +// postfix-tail = "[" expr "]" +// | "(" func-args ")" +// | "." ident +// | "->" ident +// | "++" +// | "--" +static Node *postfix(Token **rest, Token *tok) { + if (equal(tok, "(") && is_typename(tok->next)) { + // Compound literal + Token *start = tok; + Type *ty = typename(&tok, tok->next); + tok = skip(tok, ")"); + + if (scope->next == NULL) { + Obj *var = new_anon_gvar(ty); + gvar_initializer(rest, tok, var); + return new_var_node(var, start); + } + + Obj *var = new_lvar("", ty); + Node *lhs = lvar_initializer(rest, tok, var); + Node *rhs = new_var_node(var, tok); + return new_binary(ND_COMMA, lhs, rhs, start); + } + + Node *node = primary(&tok, tok); + + for (;;) { + if (equal(tok, "(")) { + node = funcall(&tok, tok->next, node); + continue; + } + + if (equal(tok, "[")) { + // x[y] is short for *(x+y) + Token *start = tok; + Node *idx = expr(&tok, tok->next); + tok = skip(tok, "]"); + node = new_unary(ND_DEREF, new_add(node, idx, start), start); + continue; + } + + if (equal(tok, ".")) { + node = struct_ref(node, tok->next); + tok = tok->next->next; + continue; + } + + if (equal(tok, "->")) { + // x->y is short for (*x).y + node = new_unary(ND_DEREF, node, tok); + node = struct_ref(node, tok->next); + tok = tok->next->next; + continue; + } + + if (equal(tok, "++")) { + node = new_inc_dec(node, tok, 1); + tok = tok->next; + continue; + } + + if (equal(tok, "--")) { + node = new_inc_dec(node, tok, -1); + tok = tok->next; + continue; + } + + *rest = tok; + return node; + } +} + +// funcall = (assign ("," assign)*)? ")" +static Node *funcall(Token **rest, Token *tok, Node *fn) { + add_type(fn); + + if (fn->ty->kind != TY_FUNC && + (fn->ty->kind != TY_PTR || fn->ty->base->kind != TY_FUNC)) + error_tok(fn->tok, "not a function"); + + Type *ty = (fn->ty->kind == TY_FUNC) ? fn->ty : fn->ty->base; + Type *param_ty = ty->params; + + Node head = {}; + Node *cur = &head; + + while (!equal(tok, ")")) { + if (cur != &head) + tok = skip(tok, ","); + + Node *arg = assign(&tok, tok); + add_type(arg); + + if (!param_ty && !ty->is_variadic) + error_tok(tok, "too many arguments"); + + if (param_ty) { + if (param_ty->kind != TY_STRUCT && param_ty->kind != TY_UNION) + arg = new_cast(arg, param_ty); + param_ty = param_ty->next; + } else if (arg->ty->kind == TY_FLOAT) { + // If parameter type is omitted (e.g. in "..."), float + // arguments are promoted to double. + arg = new_cast(arg, ty_double); + } + + cur = cur->next = arg; + } + + if (param_ty) + error_tok(tok, "too few arguments"); + + *rest = skip(tok, ")"); + + Node *node = new_unary(ND_FUNCALL, fn, tok); + node->func_ty = ty; + node->ty = ty->return_ty; + node->args = head.next; + + // If a function returns a struct, it is caller's responsibility + // to allocate a space for the return value. + if (node->ty->kind == TY_STRUCT || node->ty->kind == TY_UNION) + node->ret_buffer = new_lvar("", node->ty); + return node; +} + +// generic-selection = "(" assign "," generic-assoc ("," generic-assoc)* ")" +// +// generic-assoc = type-name ":" assign +// | "default" ":" assign +static Node *generic_selection(Token **rest, Token *tok) { + Token *start = tok; + tok = skip(tok, "("); + + Node *ctrl = assign(&tok, tok); + add_type(ctrl); + + Type *t1 = ctrl->ty; + if (t1->kind == TY_FUNC) + t1 = pointer_to(t1); + else if (t1->kind == TY_ARRAY) + t1 = pointer_to(t1->base); + + Node *ret = NULL; + + while (!consume(rest, tok, ")")) { + tok = skip(tok, ","); + + if (equal(tok, "default")) { + tok = skip(tok->next, ":"); + Node *node = assign(&tok, tok); + if (!ret) + ret = node; + continue; + } + + Type *t2 = typename(&tok, tok); + tok = skip(tok, ":"); + Node *node = assign(&tok, tok); + if (is_compatible(t1, t2)) + ret = node; + } + + if (!ret) + error_tok(start, "controlling expression type not compatible with" + " any generic association type"); + return ret; +} + +// primary = "(" "{" stmt+ "}" ")" +// | "(" expr ")" +// | "sizeof" "(" type-name ")" +// | "sizeof" unary +// | "_Alignof" "(" type-name ")" +// | "_Alignof" unary +// | "_Generic" generic-selection +// | "__builtin_types_compatible_p" "(" type-name, type-name, ")" +// | "__builtin_reg_class" "(" type-name ")" +// | ident +// | str +// | num +static Node *primary(Token **rest, Token *tok) { + Token *start = tok; + + if (equal(tok, "(") && equal(tok->next, "{")) { + // This is a GNU statement expresssion. + Node *node = new_node(ND_STMT_EXPR, tok); + node->body = compound_stmt(&tok, tok->next->next)->body; + *rest = skip(tok, ")"); + return node; + } + + if (equal(tok, "(")) { + Node *node = expr(&tok, tok->next); + *rest = skip(tok, ")"); + return node; + } + + if (equal(tok, "sizeof") && equal(tok->next, "(") && is_typename(tok->next->next)) { + Type *ty = typename(&tok, tok->next->next); + *rest = skip(tok, ")"); + + if (ty->kind == TY_VLA) { + if (ty->vla_size) + return new_var_node(ty->vla_size, tok); + + Node *lhs = compute_vla_size(ty, tok); + Node *rhs = new_var_node(ty->vla_size, tok); + return new_binary(ND_COMMA, lhs, rhs, tok); + } + + return new_ulong(ty->size, start); + } + + if (equal(tok, "sizeof")) { + Node *node = unary(rest, tok->next); + add_type(node); + if (node->ty->kind == TY_VLA) + return new_var_node(node->ty->vla_size, tok); + return new_ulong(node->ty->size, tok); + } + + if (equal(tok, "_Alignof") && equal(tok->next, "(") && is_typename(tok->next->next)) { + Type *ty = typename(&tok, tok->next->next); + *rest = skip(tok, ")"); + return new_ulong(ty->align, tok); + } + + if (equal(tok, "_Alignof")) { + Node *node = unary(rest, tok->next); + add_type(node); + return new_ulong(node->ty->align, tok); + } + + if (equal(tok, "_Generic")) + return generic_selection(rest, tok->next); + + if (equal(tok, "__builtin_types_compatible_p")) { + tok = skip(tok->next, "("); + Type *t1 = typename(&tok, tok); + tok = skip(tok, ","); + Type *t2 = typename(&tok, tok); + *rest = skip(tok, ")"); + return new_num(is_compatible(t1, t2), start); + } + + if (equal(tok, "__builtin_reg_class")) { + tok = skip(tok->next, "("); + Type *ty = typename(&tok, tok); + *rest = skip(tok, ")"); + + if (is_integer(ty) || ty->kind == TY_PTR) + return new_num(0, start); + if (is_flonum(ty)) + return new_num(1, start); + return new_num(2, start); + } + + if (equal(tok, "__builtin_compare_and_swap")) { + Node *node = new_node(ND_CAS, tok); + tok = skip(tok->next, "("); + node->cas_addr = assign(&tok, tok); + tok = skip(tok, ","); + node->cas_old = assign(&tok, tok); + tok = skip(tok, ","); + node->cas_new = assign(&tok, tok); + *rest = skip(tok, ")"); + return node; + } + + if (equal(tok, "__builtin_atomic_exchange")) { + Node *node = new_node(ND_EXCH, tok); + tok = skip(tok->next, "("); + node->lhs = assign(&tok, tok); + tok = skip(tok, ","); + node->rhs = assign(&tok, tok); + *rest = skip(tok, ")"); + return node; + } + + if (tok->kind == TK_IDENT) { + // Variable or enum constant + VarScope *sc = find_var(tok); + *rest = tok->next; + + // For "static inline" function + if (sc && sc->var && sc->var->is_function) { + if (current_fn) + strarray_push(¤t_fn->refs, sc->var->name); + else + sc->var->is_root = true; + } + + if (sc) { + if (sc->var) + return new_var_node(sc->var, tok); + if (sc->enum_ty) + return new_num(sc->enum_val, tok); + } + + if (equal(tok->next, "(")) + error_tok(tok, "implicit declaration of a function"); + error_tok(tok, "undefined variable"); + } + + if (tok->kind == TK_STR) { + Obj *var = new_string_literal(tok->str, tok->ty); + *rest = tok->next; + return new_var_node(var, tok); + } + + if (tok->kind == TK_NUM) { + Node *node; + if (is_flonum(tok->ty)) { + node = new_node(ND_NUM, tok); + node->fval = tok->fval; + } else { + node = new_num(tok->val, tok); + } + + node->ty = tok->ty; + *rest = tok->next; + return node; + } + + error_tok(tok, "expected an expression"); +} + +static Token *parse_typedef(Token *tok, Type *basety) { + bool first = true; + + while (!consume(&tok, tok, ";")) { + if (!first) + tok = skip(tok, ","); + first = false; + + Type *ty = declarator(&tok, tok, basety); + if (!ty->name) + error_tok(ty->name_pos, "typedef name omitted"); + push_scope(get_ident(ty->name))->type_def = ty; + } + return tok; +} + +static void create_param_lvars(Type *param) { + if (param) { + create_param_lvars(param->next); + if (!param->name) + error_tok(param->name_pos, "parameter name omitted"); + new_lvar(get_ident(param->name), param); + } +} + +// This function matches gotos or labels-as-values with labels. +// +// We cannot resolve gotos as we parse a function because gotos +// can refer a label that appears later in the function. +// So, we need to do this after we parse the entire function. +static void resolve_goto_labels(void) { + for (Node *x = gotos; x; x = x->goto_next) { + for (Node *y = labels; y; y = y->goto_next) { + if (!strcmp(x->label, y->label)) { + x->unique_label = y->unique_label; + break; + } + } + + if (x->unique_label == NULL) + error_tok(x->tok->next, "use of undeclared label"); + } + + gotos = labels = NULL; +} + +static Obj *find_func(char *name) { + Scope *sc = scope; + while (sc->next) + sc = sc->next; + + VarScope *sc2 = hashmap_get(&sc->vars, name); + if (sc2 && sc2->var && sc2->var->is_function) + return sc2->var; + return NULL; +} + +static void mark_live(Obj *var) { + if (!var->is_function || var->is_live) + return; + var->is_live = true; + + for (int i = 0; i < var->refs.len; i++) { + Obj *fn = find_func(var->refs.data[i]); + if (fn) + mark_live(fn); + } +} + +static Token *function(Token *tok, Type *basety, VarAttr *attr) { + Type *ty = declarator(&tok, tok, basety); + if (!ty->name) + error_tok(ty->name_pos, "function name omitted"); + char *name_str = get_ident(ty->name); + + Obj *fn = find_func(name_str); + if (fn) { + // Redeclaration + if (!fn->is_function) + error_tok(tok, "redeclared as a different kind of symbol"); + if (fn->is_definition && equal(tok, "{")) + error_tok(tok, "redefinition of %s", name_str); + if (!fn->is_static && attr->is_static) + error_tok(tok, "static declaration follows a non-static declaration"); + fn->is_definition = fn->is_definition || equal(tok, "{"); + } else { + fn = new_gvar(name_str, ty); + fn->is_function = true; + fn->is_definition = equal(tok, "{"); + fn->is_static = attr->is_static || (attr->is_inline && !attr->is_extern); + fn->is_inline = attr->is_inline; + } + + fn->is_root = !(fn->is_static && fn->is_inline); + + if (consume(&tok, tok, ";")) + return tok; + + current_fn = fn; + locals = NULL; + enter_scope(); + create_param_lvars(ty->params); + + // A buffer for a struct/union return value is passed + // as the hidden first parameter. + Type *rty = ty->return_ty; + if ((rty->kind == TY_STRUCT || rty->kind == TY_UNION) && rty->size > 16) + new_lvar("", pointer_to(rty)); + + fn->params = locals; + + if (ty->is_variadic) + fn->va_area = new_lvar("__va_area__", array_of(ty_char, 136)); + fn->alloca_bottom = new_lvar("__alloca_size__", pointer_to(ty_char)); + + tok = skip(tok, "{"); + + // [https://www.sigbus.info/n1570#6.4.2.2p1] "__func__" is + // automatically defined as a local variable containing the + // current function name. + push_scope("__func__")->var = + new_string_literal(fn->name, array_of(ty_char, strlen(fn->name) + 1)); + + // [GNU] __FUNCTION__ is yet another name of __func__. + push_scope("__FUNCTION__")->var = + new_string_literal(fn->name, array_of(ty_char, strlen(fn->name) + 1)); + + fn->body = compound_stmt(&tok, tok); + fn->locals = locals; + leave_scope(); + resolve_goto_labels(); + return tok; +} + +static Token *global_variable(Token *tok, Type *basety, VarAttr *attr) { + bool first = true; + + while (!consume(&tok, tok, ";")) { + if (!first) + tok = skip(tok, ","); + first = false; + + Type *ty = declarator(&tok, tok, basety); + if (!ty->name) + error_tok(ty->name_pos, "variable name omitted"); + + Obj *var = new_gvar(get_ident(ty->name), ty); + var->is_definition = !attr->is_extern; + var->is_static = attr->is_static; + var->is_tls = attr->is_tls; + if (attr->align) + var->align = attr->align; + + if (equal(tok, "=")) + gvar_initializer(&tok, tok->next, var); + else if (!attr->is_extern && !attr->is_tls) + var->is_tentative = true; + } + return tok; +} + +// Lookahead tokens and returns true if a given token is a start +// of a function definition or declaration. +static bool is_function(Token *tok) { + if (equal(tok, ";")) + return false; + + Type dummy = {}; + Type *ty = declarator(&tok, tok, &dummy); + return ty->kind == TY_FUNC; +} + +// Remove redundant tentative definitions. +static void scan_globals(void) { + Obj head; + Obj *cur = &head; + + for (Obj *var = globals; var; var = var->next) { + if (!var->is_tentative) { + cur = cur->next = var; + continue; + } + + // Find another definition of the same identifier. + Obj *var2 = globals; + for (; var2; var2 = var2->next) + if (var != var2 && var2->is_definition && !strcmp(var->name, var2->name)) + break; + + // If there's another definition, the tentative definition + // is redundant + if (!var2) + cur = cur->next = var; + } + + cur->next = NULL; + globals = head.next; +} + +static void declare_builtin_functions(void) { + Type *ty = func_type(pointer_to(ty_void)); + ty->params = copy_type(ty_int); + builtin_alloca = new_gvar("alloca", ty); + builtin_alloca->is_definition = false; +} + +// program = (typedef | function-definition | global-variable)* +Obj *parse(Token *tok) { + declare_builtin_functions(); + globals = NULL; + + while (tok->kind != TK_EOF) { + VarAttr attr = {}; + Type *basety = declspec(&tok, tok, &attr); + + // Typedef + if (attr.is_typedef) { + tok = parse_typedef(tok, basety); + continue; + } + + // Function + if (is_function(tok)) { + tok = function(tok, basety, &attr); + continue; + } + + // Global variable + tok = global_variable(tok, basety, &attr); + } + + for (Obj *var = globals; var; var = var->next) + if (var->is_root) + mark_live(var); + + // Remove redundant tentative definitions. + scan_globals(); + return globals; +} diff --git a/src/3p/chibicc/preprocess.c b/src/3p/chibicc/preprocess.c new file mode 100644 index 0000000..cd8d1d8 --- /dev/null +++ b/src/3p/chibicc/preprocess.c @@ -0,0 +1,1208 @@ +// This file implements the C preprocessor. +// +// The preprocessor takes a list of tokens as an input and returns a +// new list of tokens as an output. +// +// The preprocessing language is designed in such a way that that's +// guaranteed to stop even if there is a recursive macro. +// Informally speaking, a macro is applied only once for each token. +// That is, if a macro token T appears in a result of direct or +// indirect macro expansion of T, T won't be expanded any further. +// For example, if T is defined as U, and U is defined as T, then +// token T is expanded to U and then to T and the macro expansion +// stops at that point. +// +// To achieve the above behavior, we attach for each token a set of +// macro names from which the token is expanded. The set is called +// "hideset". Hideset is initially empty, and every time we expand a +// macro, the macro name is added to the resulting tokens' hidesets. +// +// The above macro expansion algorithm is explained in this document +// written by Dave Prossor, which is used as a basis for the +// standard's wording: +// https://github.com/rui314/chibicc/wiki/cpp.algo.pdf + +#include "chibicc.h" + +typedef struct MacroParam MacroParam; +struct MacroParam { + MacroParam *next; + char *name; +}; + +typedef struct MacroArg MacroArg; +struct MacroArg { + MacroArg *next; + char *name; + bool is_va_args; + Token *tok; +}; + +typedef Token *macro_handler_fn(Token *); + +typedef struct Macro Macro; +struct Macro { + char *name; + bool is_objlike; // Object-like or function-like + MacroParam *params; + char *va_args_name; + Token *body; + macro_handler_fn *handler; +}; + +// `#if` can be nested, so we use a stack to manage nested `#if`s. +typedef struct CondIncl CondIncl; +struct CondIncl { + CondIncl *next; + enum { IN_THEN, IN_ELIF, IN_ELSE } ctx; + Token *tok; + bool included; +}; + +typedef struct Hideset Hideset; +struct Hideset { + Hideset *next; + char *name; +}; + +static HashMap macros; +static CondIncl *cond_incl; +static HashMap pragma_once; +static int include_next_idx; + +static Token *preprocess2(Token *tok); +static Macro *find_macro(Token *tok); + +static bool is_hash(Token *tok) { + return tok->at_bol && equal(tok, "#"); +} + +// Some preprocessor directives such as #include allow extraneous +// tokens before newline. This function skips such tokens. +static Token *skip_line(Token *tok) { + if (tok->at_bol) + return tok; + warn_tok(tok, "extra token"); + while (!tok->at_bol) + tok = tok->next; + return tok; +} + +static Token *copy_token(Token *tok) { + Token *t = calloc(1, sizeof(Token)); + *t = *tok; + t->next = NULL; + return t; +} + +static Token *new_eof(Token *tok) { + Token *t = copy_token(tok); + t->kind = TK_EOF; + t->len = 0; + return t; +} + +static Hideset *new_hideset(char *name) { + Hideset *hs = calloc(1, sizeof(Hideset)); + hs->name = name; + return hs; +} + +static Hideset *hideset_union(Hideset *hs1, Hideset *hs2) { + Hideset head = {}; + Hideset *cur = &head; + + for (; hs1; hs1 = hs1->next) + cur = cur->next = new_hideset(hs1->name); + cur->next = hs2; + return head.next; +} + +static bool hideset_contains(Hideset *hs, char *s, int len) { + for (; hs; hs = hs->next) + if (strlen(hs->name) == len && !strncmp(hs->name, s, len)) + return true; + return false; +} + +static Hideset *hideset_intersection(Hideset *hs1, Hideset *hs2) { + Hideset head = {}; + Hideset *cur = &head; + + for (; hs1; hs1 = hs1->next) + if (hideset_contains(hs2, hs1->name, strlen(hs1->name))) + cur = cur->next = new_hideset(hs1->name); + return head.next; +} + +static Token *add_hideset(Token *tok, Hideset *hs) { + Token head = {}; + Token *cur = &head; + + for (; tok; tok = tok->next) { + Token *t = copy_token(tok); + t->hideset = hideset_union(t->hideset, hs); + cur = cur->next = t; + } + return head.next; +} + +// Append tok2 to the end of tok1. +static Token *append(Token *tok1, Token *tok2) { + if (tok1->kind == TK_EOF) + return tok2; + + Token head = {}; + Token *cur = &head; + + for (; tok1->kind != TK_EOF; tok1 = tok1->next) + cur = cur->next = copy_token(tok1); + cur->next = tok2; + return head.next; +} + +static Token *skip_cond_incl2(Token *tok) { + while (tok->kind != TK_EOF) { + if (is_hash(tok) && + (equal(tok->next, "if") || equal(tok->next, "ifdef") || + equal(tok->next, "ifndef"))) { + tok = skip_cond_incl2(tok->next->next); + continue; + } + if (is_hash(tok) && equal(tok->next, "endif")) + return tok->next->next; + tok = tok->next; + } + return tok; +} + +// Skip until next `#else`, `#elif` or `#endif`. +// Nested `#if` and `#endif` are skipped. +static Token *skip_cond_incl(Token *tok) { + while (tok->kind != TK_EOF) { + if (is_hash(tok) && + (equal(tok->next, "if") || equal(tok->next, "ifdef") || + equal(tok->next, "ifndef"))) { + tok = skip_cond_incl2(tok->next->next); + continue; + } + + if (is_hash(tok) && + (equal(tok->next, "elif") || equal(tok->next, "else") || + equal(tok->next, "endif"))) + break; + tok = tok->next; + } + return tok; +} + +// Double-quote a given string and returns it. +static char *quote_string(char *str) { + int bufsize = 3; + for (int i = 0; str[i]; i++) { + if (str[i] == '\\' || str[i] == '"') + bufsize++; + bufsize++; + } + + char *buf = calloc(1, bufsize); + char *p = buf; + *p++ = '"'; + for (int i = 0; str[i]; i++) { + if (str[i] == '\\' || str[i] == '"') + *p++ = '\\'; + *p++ = str[i]; + } + *p++ = '"'; + *p++ = '\0'; + return buf; +} + +static Token *new_str_token(char *str, Token *tmpl) { + char *buf = quote_string(str); + return tokenize(new_file(tmpl->file->name, tmpl->file->file_no, buf)); +} + +// Copy all tokens until the next newline, terminate them with +// an EOF token and then returns them. This function is used to +// create a new list of tokens for `#if` arguments. +static Token *copy_line(Token **rest, Token *tok) { + Token head = {}; + Token *cur = &head; + + for (; !tok->at_bol; tok = tok->next) + cur = cur->next = copy_token(tok); + + cur->next = new_eof(tok); + *rest = tok; + return head.next; +} + +static Token *new_num_token(int val, Token *tmpl) { + char *buf = format("%d\n", val); + return tokenize(new_file(tmpl->file->name, tmpl->file->file_no, buf)); +} + +static Token *read_const_expr(Token **rest, Token *tok) { + tok = copy_line(rest, tok); + + Token head = {}; + Token *cur = &head; + + while (tok->kind != TK_EOF) { + // "defined(foo)" or "defined foo" becomes "1" if macro "foo" + // is defined. Otherwise "0". + if (equal(tok, "defined")) { + Token *start = tok; + bool has_paren = consume(&tok, tok->next, "("); + + if (tok->kind != TK_IDENT) + error_tok(start, "macro name must be an identifier"); + Macro *m = find_macro(tok); + tok = tok->next; + + if (has_paren) + tok = skip(tok, ")"); + + cur = cur->next = new_num_token(m ? 1 : 0, start); + continue; + } + + cur = cur->next = tok; + tok = tok->next; + } + + cur->next = tok; + return head.next; +} + +// Read and evaluate a constant expression. +static long eval_const_expr(Token **rest, Token *tok) { + Token *start = tok; + Token *expr = read_const_expr(rest, tok->next); + expr = preprocess2(expr); + + if (expr->kind == TK_EOF) + error_tok(start, "no expression"); + + // [https://www.sigbus.info/n1570#6.10.1p4] The standard requires + // we replace remaining non-macro identifiers with "0" before + // evaluating a constant expression. For example, `#if foo` is + // equivalent to `#if 0` if foo is not defined. + for (Token *t = expr; t->kind != TK_EOF; t = t->next) { + if (t->kind == TK_IDENT) { + Token *next = t->next; + *t = *new_num_token(0, t); + t->next = next; + } + } + + // Convert pp-numbers to regular numbers + convert_pp_tokens(expr); + + Token *rest2; + long val = const_expr(&rest2, expr); + if (rest2->kind != TK_EOF) + error_tok(rest2, "extra token"); + return val; +} + +static CondIncl *push_cond_incl(Token *tok, bool included) { + CondIncl *ci = calloc(1, sizeof(CondIncl)); + ci->next = cond_incl; + ci->ctx = IN_THEN; + ci->tok = tok; + ci->included = included; + cond_incl = ci; + return ci; +} + +static Macro *find_macro(Token *tok) { + if (tok->kind != TK_IDENT) + return NULL; + return hashmap_get2(¯os, tok->loc, tok->len); +} + +static Macro *add_macro(char *name, bool is_objlike, Token *body) { + Macro *m = calloc(1, sizeof(Macro)); + m->name = name; + m->is_objlike = is_objlike; + m->body = body; + hashmap_put(¯os, name, m); + return m; +} + +static MacroParam *read_macro_params(Token **rest, Token *tok, char **va_args_name) { + MacroParam head = {}; + MacroParam *cur = &head; + + while (!equal(tok, ")")) { + if (cur != &head) + tok = skip(tok, ","); + + if (equal(tok, "...")) { + *va_args_name = "__VA_ARGS__"; + *rest = skip(tok->next, ")"); + return head.next; + } + + if (tok->kind != TK_IDENT) + error_tok(tok, "expected an identifier"); + + if (equal(tok->next, "...")) { + *va_args_name = strndup(tok->loc, tok->len); + *rest = skip(tok->next->next, ")"); + return head.next; + } + + MacroParam *m = calloc(1, sizeof(MacroParam)); + m->name = strndup(tok->loc, tok->len); + cur = cur->next = m; + tok = tok->next; + } + + *rest = tok->next; + return head.next; +} + +static void read_macro_definition(Token **rest, Token *tok) { + if (tok->kind != TK_IDENT) + error_tok(tok, "macro name must be an identifier"); + char *name = strndup(tok->loc, tok->len); + tok = tok->next; + + if (!tok->has_space && equal(tok, "(")) { + // Function-like macro + char *va_args_name = NULL; + MacroParam *params = read_macro_params(&tok, tok->next, &va_args_name); + + Macro *m = add_macro(name, false, copy_line(rest, tok)); + m->params = params; + m->va_args_name = va_args_name; + } else { + // Object-like macro + add_macro(name, true, copy_line(rest, tok)); + } +} + +static MacroArg *read_macro_arg_one(Token **rest, Token *tok, bool read_rest) { + Token head = {}; + Token *cur = &head; + int level = 0; + + for (;;) { + if (level == 0 && equal(tok, ")")) + break; + if (level == 0 && !read_rest && equal(tok, ",")) + break; + + if (tok->kind == TK_EOF) + error_tok(tok, "premature end of input"); + + if (equal(tok, "(")) + level++; + else if (equal(tok, ")")) + level--; + + cur = cur->next = copy_token(tok); + tok = tok->next; + } + + cur->next = new_eof(tok); + + MacroArg *arg = calloc(1, sizeof(MacroArg)); + arg->tok = head.next; + *rest = tok; + return arg; +} + +static MacroArg * +read_macro_args(Token **rest, Token *tok, MacroParam *params, char *va_args_name) { + Token *start = tok; + tok = tok->next->next; + + MacroArg head = {}; + MacroArg *cur = &head; + + MacroParam *pp = params; + for (; pp; pp = pp->next) { + if (cur != &head) + tok = skip(tok, ","); + cur = cur->next = read_macro_arg_one(&tok, tok, false); + cur->name = pp->name; + } + + if (va_args_name) { + MacroArg *arg; + if (equal(tok, ")")) { + arg = calloc(1, sizeof(MacroArg)); + arg->tok = new_eof(tok); + } else { + if (pp != params) + tok = skip(tok, ","); + arg = read_macro_arg_one(&tok, tok, true); + } + arg->name = va_args_name;; + arg->is_va_args = true; + cur = cur->next = arg; + } else if (pp) { + error_tok(start, "too many arguments"); + } + + skip(tok, ")"); + *rest = tok; + return head.next; +} + +static MacroArg *find_arg(MacroArg *args, Token *tok) { + for (MacroArg *ap = args; ap; ap = ap->next) + if (tok->len == strlen(ap->name) && !strncmp(tok->loc, ap->name, tok->len)) + return ap; + return NULL; +} + +// Concatenates all tokens in `tok` and returns a new string. +static char *join_tokens(Token *tok, Token *end) { + // Compute the length of the resulting token. + int len = 1; + for (Token *t = tok; t != end && t->kind != TK_EOF; t = t->next) { + if (t != tok && t->has_space) + len++; + len += t->len; + } + + char *buf = calloc(1, len); + + // Copy token texts. + int pos = 0; + for (Token *t = tok; t != end && t->kind != TK_EOF; t = t->next) { + if (t != tok && t->has_space) + buf[pos++] = ' '; + strncpy(buf + pos, t->loc, t->len); + pos += t->len; + } + buf[pos] = '\0'; + return buf; +} + +// Concatenates all tokens in `arg` and returns a new string token. +// This function is used for the stringizing operator (#). +static Token *stringize(Token *hash, Token *arg) { + // Create a new string token. We need to set some value to its + // source location for error reporting function, so we use a macro + // name token as a template. + char *s = join_tokens(arg, NULL); + return new_str_token(s, hash); +} + +// Concatenate two tokens to create a new token. +static Token *paste(Token *lhs, Token *rhs) { + // Paste the two tokens. + char *buf = format("%.*s%.*s", lhs->len, lhs->loc, rhs->len, rhs->loc); + + // Tokenize the resulting string. + Token *tok = tokenize(new_file(lhs->file->name, lhs->file->file_no, buf)); + if (tok->next->kind != TK_EOF) + error_tok(lhs, "pasting forms '%s', an invalid token", buf); + return tok; +} + +static bool has_varargs(MacroArg *args) { + for (MacroArg *ap = args; ap; ap = ap->next) + if (!strcmp(ap->name, "__VA_ARGS__")) + return ap->tok->kind != TK_EOF; + return false; +} + +// Replace func-like macro parameters with given arguments. +static Token *subst(Token *tok, MacroArg *args) { + Token head = {}; + Token *cur = &head; + + while (tok->kind != TK_EOF) { + // "#" followed by a parameter is replaced with stringized actuals. + if (equal(tok, "#")) { + MacroArg *arg = find_arg(args, tok->next); + if (!arg) + error_tok(tok->next, "'#' is not followed by a macro parameter"); + cur = cur->next = stringize(tok, arg->tok); + tok = tok->next->next; + continue; + } + + // [GNU] If __VA_ARG__ is empty, `,##__VA_ARGS__` is expanded + // to the empty token list. Otherwise, its expaned to `,` and + // __VA_ARGS__. + if (equal(tok, ",") && equal(tok->next, "##")) { + MacroArg *arg = find_arg(args, tok->next->next); + if (arg && arg->is_va_args) { + if (arg->tok->kind == TK_EOF) { + tok = tok->next->next->next; + } else { + cur = cur->next = copy_token(tok); + tok = tok->next->next; + } + continue; + } + } + + if (equal(tok, "##")) { + if (cur == &head) + error_tok(tok, "'##' cannot appear at start of macro expansion"); + + if (tok->next->kind == TK_EOF) + error_tok(tok, "'##' cannot appear at end of macro expansion"); + + MacroArg *arg = find_arg(args, tok->next); + if (arg) { + if (arg->tok->kind != TK_EOF) { + *cur = *paste(cur, arg->tok); + for (Token *t = arg->tok->next; t->kind != TK_EOF; t = t->next) + cur = cur->next = copy_token(t); + } + tok = tok->next->next; + continue; + } + + *cur = *paste(cur, tok->next); + tok = tok->next->next; + continue; + } + + MacroArg *arg = find_arg(args, tok); + + if (arg && equal(tok->next, "##")) { + Token *rhs = tok->next->next; + + if (arg->tok->kind == TK_EOF) { + MacroArg *arg2 = find_arg(args, rhs); + if (arg2) { + for (Token *t = arg2->tok; t->kind != TK_EOF; t = t->next) + cur = cur->next = copy_token(t); + } else { + cur = cur->next = copy_token(rhs); + } + tok = rhs->next; + continue; + } + + for (Token *t = arg->tok; t->kind != TK_EOF; t = t->next) + cur = cur->next = copy_token(t); + tok = tok->next; + continue; + } + + // If __VA_ARG__ is empty, __VA_OPT__(x) is expanded to the + // empty token list. Otherwise, __VA_OPT__(x) is expanded to x. + if (equal(tok, "__VA_OPT__") && equal(tok->next, "(")) { + MacroArg *arg = read_macro_arg_one(&tok, tok->next->next, true); + if (has_varargs(args)) + for (Token *t = arg->tok; t->kind != TK_EOF; t = t->next) + cur = cur->next = t; + tok = skip(tok, ")"); + continue; + } + + // Handle a macro token. Macro arguments are completely macro-expanded + // before they are substituted into a macro body. + if (arg) { + Token *t = preprocess2(arg->tok); + t->at_bol = tok->at_bol; + t->has_space = tok->has_space; + for (; t->kind != TK_EOF; t = t->next) + cur = cur->next = copy_token(t); + tok = tok->next; + continue; + } + + // Handle a non-macro token. + cur = cur->next = copy_token(tok); + tok = tok->next; + continue; + } + + cur->next = tok; + return head.next; +} + +// If tok is a macro, expand it and return true. +// Otherwise, do nothing and return false. +static bool expand_macro(Token **rest, Token *tok) { + if (hideset_contains(tok->hideset, tok->loc, tok->len)) + return false; + + Macro *m = find_macro(tok); + if (!m) + return false; + + // Built-in dynamic macro application such as __LINE__ + if (m->handler) { + *rest = m->handler(tok); + (*rest)->next = tok->next; + return true; + } + + // Object-like macro application + if (m->is_objlike) { + Hideset *hs = hideset_union(tok->hideset, new_hideset(m->name)); + Token *body = add_hideset(m->body, hs); + for (Token *t = body; t->kind != TK_EOF; t = t->next) + t->origin = tok; + *rest = append(body, tok->next); + (*rest)->at_bol = tok->at_bol; + (*rest)->has_space = tok->has_space; + return true; + } + + // If a funclike macro token is not followed by an argument list, + // treat it as a normal identifier. + if (!equal(tok->next, "(")) + return false; + + // Function-like macro application + Token *macro_token = tok; + MacroArg *args = read_macro_args(&tok, tok, m->params, m->va_args_name); + Token *rparen = tok; + + // Tokens that consist a func-like macro invocation may have different + // hidesets, and if that's the case, it's not clear what the hideset + // for the new tokens should be. We take the interesection of the + // macro token and the closing parenthesis and use it as a new hideset + // as explained in the Dave Prossor's algorithm. + Hideset *hs = hideset_intersection(macro_token->hideset, rparen->hideset); + hs = hideset_union(hs, new_hideset(m->name)); + + Token *body = subst(m->body, args); + body = add_hideset(body, hs); + for (Token *t = body; t->kind != TK_EOF; t = t->next) + t->origin = macro_token; + *rest = append(body, tok->next); + (*rest)->at_bol = macro_token->at_bol; + (*rest)->has_space = macro_token->has_space; + return true; +} + +char *search_include_paths(char *filename) { + if (filename[0] == '/') + return filename; + + static HashMap cache; + char *cached = hashmap_get(&cache, filename); + if (cached) + return cached; + + // Search a file from the include paths. + for (int i = 0; i < include_paths.len; i++) { + char *path = format("%s/%s", include_paths.data[i], filename); + if (!file_exists(path)) + continue; + hashmap_put(&cache, filename, path); + include_next_idx = i + 1; + return path; + } + return NULL; +} + +static char *search_include_next(char *filename) { + for (; include_next_idx < include_paths.len; include_next_idx++) { + char *path = format("%s/%s", include_paths.data[include_next_idx], filename); + if (file_exists(path)) + return path; + } + return NULL; +} + +// Read an #include argument. +static char *read_include_filename(Token **rest, Token *tok, bool *is_dquote) { + // Pattern 1: #include "foo.h" + if (tok->kind == TK_STR) { + // A double-quoted filename for #include is a special kind of + // token, and we don't want to interpret any escape sequences in it. + // For example, "\f" in "C:\foo" is not a formfeed character but + // just two non-control characters, backslash and f. + // So we don't want to use token->str. + *is_dquote = true; + *rest = skip_line(tok->next); + return strndup(tok->loc + 1, tok->len - 2); + } + + // Pattern 2: #include + if (equal(tok, "<")) { + // Reconstruct a filename from a sequence of tokens between + // "<" and ">". + Token *start = tok; + + // Find closing ">". + for (; !equal(tok, ">"); tok = tok->next) + if (tok->at_bol || tok->kind == TK_EOF) + error_tok(tok, "expected '>'"); + + *is_dquote = false; + *rest = skip_line(tok->next); + return join_tokens(start->next, tok); + } + + // Pattern 3: #include FOO + // In this case FOO must be macro-expanded to either + // a single string token or a sequence of "<" ... ">". + if (tok->kind == TK_IDENT) { + Token *tok2 = preprocess2(copy_line(rest, tok)); + return read_include_filename(&tok2, tok2, is_dquote); + } + + error_tok(tok, "expected a filename"); +} + +// Detect the following "include guard" pattern. +// +// #ifndef FOO_H +// #define FOO_H +// ... +// #endif +static char *detect_include_guard(Token *tok) { + // Detect the first two lines. + if (!is_hash(tok) || !equal(tok->next, "ifndef")) + return NULL; + tok = tok->next->next; + + if (tok->kind != TK_IDENT) + return NULL; + + char *macro = strndup(tok->loc, tok->len); + tok = tok->next; + + if (!is_hash(tok) || !equal(tok->next, "define") || !equal(tok->next->next, macro)) + return NULL; + + // Read until the end of the file. + while (tok->kind != TK_EOF) { + if (!is_hash(tok)) { + tok = tok->next; + continue; + } + + if (equal(tok->next, "endif") && tok->next->next->kind == TK_EOF) + return macro; + + if (equal(tok, "if") || equal(tok, "ifdef") || equal(tok, "ifndef")) + tok = skip_cond_incl(tok->next); + else + tok = tok->next; + } + return NULL; +} + +static Token *include_file(Token *tok, char *path, Token *filename_tok) { + // Check for "#pragma once" + if (hashmap_get(&pragma_once, path)) + return tok; + + // If we read the same file before, and if the file was guarded + // by the usual #ifndef ... #endif pattern, we may be able to + // skip the file without opening it. + static HashMap include_guards; + char *guard_name = hashmap_get(&include_guards, path); + if (guard_name && hashmap_get(¯os, guard_name)) + return tok; + + Token *tok2 = tokenize_file(path); + if (!tok2) + error_tok(filename_tok, "%s: cannot open file: %s", path, strerror(errno)); + + guard_name = detect_include_guard(tok2); + if (guard_name) + hashmap_put(&include_guards, path, guard_name); + + return append(tok2, tok); +} + +// Read #line arguments +static void read_line_marker(Token **rest, Token *tok) { + Token *start = tok; + tok = preprocess(copy_line(rest, tok)); + + if (tok->kind != TK_NUM || tok->ty->kind != TY_INT) + error_tok(tok, "invalid line marker"); + start->file->line_delta = tok->val - start->line_no; + + tok = tok->next; + if (tok->kind == TK_EOF) + return; + + if (tok->kind != TK_STR) + error_tok(tok, "filename expected"); + start->file->display_name = tok->str; +} + +// Visit all tokens in `tok` while evaluating preprocessing +// macros and directives. +static Token *preprocess2(Token *tok) { + Token head = {}; + Token *cur = &head; + + while (tok->kind != TK_EOF) { + // If it is a macro, expand it. + if (expand_macro(&tok, tok)) + continue; + + // Pass through if it is not a "#". + if (!is_hash(tok)) { + tok->line_delta = tok->file->line_delta; + tok->filename = tok->file->display_name; + cur = cur->next = tok; + tok = tok->next; + continue; + } + + Token *start = tok; + tok = tok->next; + + if (equal(tok, "include")) { + bool is_dquote; + char *filename = read_include_filename(&tok, tok->next, &is_dquote); + + if (filename[0] != '/' && is_dquote) { + char *path = format("%s/%s", dirname(strdup(start->file->name)), filename); + if (file_exists(path)) { + tok = include_file(tok, path, start->next->next); + continue; + } + } + + char *path = search_include_paths(filename); + tok = include_file(tok, path ? path : filename, start->next->next); + continue; + } + + if (equal(tok, "include_next")) { + bool ignore; + char *filename = read_include_filename(&tok, tok->next, &ignore); + char *path = search_include_next(filename); + tok = include_file(tok, path ? path : filename, start->next->next); + continue; + } + + if (equal(tok, "define")) { + read_macro_definition(&tok, tok->next); + continue; + } + + if (equal(tok, "undef")) { + tok = tok->next; + if (tok->kind != TK_IDENT) + error_tok(tok, "macro name must be an identifier"); + undef_macro(strndup(tok->loc, tok->len)); + tok = skip_line(tok->next); + continue; + } + + if (equal(tok, "if")) { + long val = eval_const_expr(&tok, tok); + push_cond_incl(start, val); + if (!val) + tok = skip_cond_incl(tok); + continue; + } + + if (equal(tok, "ifdef")) { + bool defined = find_macro(tok->next); + push_cond_incl(tok, defined); + tok = skip_line(tok->next->next); + if (!defined) + tok = skip_cond_incl(tok); + continue; + } + + if (equal(tok, "ifndef")) { + bool defined = find_macro(tok->next); + push_cond_incl(tok, !defined); + tok = skip_line(tok->next->next); + if (defined) + tok = skip_cond_incl(tok); + continue; + } + + if (equal(tok, "elif")) { + if (!cond_incl || cond_incl->ctx == IN_ELSE) + error_tok(start, "stray #elif"); + cond_incl->ctx = IN_ELIF; + + if (!cond_incl->included && eval_const_expr(&tok, tok)) + cond_incl->included = true; + else + tok = skip_cond_incl(tok); + continue; + } + + if (equal(tok, "else")) { + if (!cond_incl || cond_incl->ctx == IN_ELSE) + error_tok(start, "stray #else"); + cond_incl->ctx = IN_ELSE; + tok = skip_line(tok->next); + + if (cond_incl->included) + tok = skip_cond_incl(tok); + continue; + } + + if (equal(tok, "endif")) { + if (!cond_incl) + error_tok(start, "stray #endif"); + cond_incl = cond_incl->next; + tok = skip_line(tok->next); + continue; + } + + if (equal(tok, "line")) { + read_line_marker(&tok, tok->next); + continue; + } + + if (tok->kind == TK_PP_NUM) { + read_line_marker(&tok, tok); + continue; + } + + if (equal(tok, "pragma") && equal(tok->next, "once")) { + hashmap_put(&pragma_once, tok->file->name, (void *)1); + tok = skip_line(tok->next->next); + continue; + } + + if (equal(tok, "pragma")) { + do { + tok = tok->next; + } while (!tok->at_bol); + continue; + } + + if (equal(tok, "error")) + error_tok(tok, "error"); + + // `#`-only line is legal. It's called a null directive. + if (tok->at_bol) + continue; + + error_tok(tok, "invalid preprocessor directive"); + } + + cur->next = tok; + return head.next; +} + +void define_macro(char *name, char *buf) { + Token *tok = tokenize(new_file("", 1, buf)); + add_macro(name, true, tok); +} + +void undef_macro(char *name) { + hashmap_delete(¯os, name); +} + +static Macro *add_builtin(char *name, macro_handler_fn *fn) { + Macro *m = add_macro(name, true, NULL); + m->handler = fn; + return m; +} + +static Token *file_macro(Token *tmpl) { + while (tmpl->origin) + tmpl = tmpl->origin; + return new_str_token(tmpl->file->display_name, tmpl); +} + +static Token *line_macro(Token *tmpl) { + while (tmpl->origin) + tmpl = tmpl->origin; + int i = tmpl->line_no + tmpl->file->line_delta; + return new_num_token(i, tmpl); +} + +// __COUNTER__ is expanded to serial values starting from 0. +static Token *counter_macro(Token *tmpl) { + static int i = 0; + return new_num_token(i++, tmpl); +} + +// __TIMESTAMP__ is expanded to a string describing the last +// modification time of the current file. E.g. +// "Fri Jul 24 01:32:50 2020" +static Token *timestamp_macro(Token *tmpl) { + struct stat st; + if (stat(tmpl->file->name, &st) != 0) + return new_str_token("??? ??? ?? ??:??:?? ????", tmpl); + + char buf[30]; + ctime_r(&st.st_mtime, buf); + buf[24] = '\0'; + return new_str_token(buf, tmpl); +} + +static Token *base_file_macro(Token *tmpl) { + return new_str_token(base_file, tmpl); +} + +// __DATE__ is expanded to the current date, e.g. "May 17 2020". +static char *format_date(struct tm *tm) { + static char mon[][4] = { + "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec", + }; + + return format("\"%s %2d %d\"", mon[tm->tm_mon], tm->tm_mday, tm->tm_year + 1900); +} + +// __TIME__ is expanded to the current time, e.g. "13:34:03". +static char *format_time(struct tm *tm) { + return format("\"%02d:%02d:%02d\"", tm->tm_hour, tm->tm_min, tm->tm_sec); +} + +void init_macros(void) { + // Define predefined macros + define_macro("_LP64", "1"); + define_macro("__C99_MACRO_WITH_VA_ARGS", "1"); + define_macro("__ELF__", "1"); + define_macro("__LP64__", "1"); + define_macro("__SIZEOF_DOUBLE__", "8"); + define_macro("__SIZEOF_FLOAT__", "4"); + define_macro("__SIZEOF_INT__", "4"); + define_macro("__SIZEOF_LONG_DOUBLE__", "8"); + define_macro("__SIZEOF_LONG_LONG__", "8"); + define_macro("__SIZEOF_LONG__", "8"); + define_macro("__SIZEOF_POINTER__", "8"); + define_macro("__SIZEOF_PTRDIFF_T__", "8"); + define_macro("__SIZEOF_SHORT__", "2"); + define_macro("__SIZEOF_SIZE_T__", "8"); + define_macro("__SIZE_TYPE__", "unsigned long"); + define_macro("__STDC_HOSTED__", "1"); + define_macro("__STDC_NO_COMPLEX__", "1"); + define_macro("__STDC_UTF_16__", "1"); + define_macro("__STDC_UTF_32__", "1"); + define_macro("__STDC_VERSION__", "201112L"); + define_macro("__STDC__", "1"); + define_macro("__USER_LABEL_PREFIX__", ""); + define_macro("__alignof__", "_Alignof"); + define_macro("__amd64", "1"); + define_macro("__amd64__", "1"); + define_macro("__chibicc__", "1"); + define_macro("__const__", "const"); + define_macro("__gnu_linux__", "1"); + define_macro("__inline__", "inline"); + define_macro("__linux", "1"); + define_macro("__linux__", "1"); + define_macro("__signed__", "signed"); + define_macro("__typeof__", "typeof"); + define_macro("__unix", "1"); + define_macro("__unix__", "1"); + define_macro("__volatile__", "volatile"); + define_macro("__x86_64", "1"); + define_macro("__x86_64__", "1"); + define_macro("linux", "1"); + define_macro("unix", "1"); + + add_builtin("__FILE__", file_macro); + add_builtin("__LINE__", line_macro); + add_builtin("__COUNTER__", counter_macro); + add_builtin("__TIMESTAMP__", timestamp_macro); + add_builtin("__BASE_FILE__", base_file_macro); + + time_t now = time(NULL); + struct tm *tm = localtime(&now); + define_macro("__DATE__", format_date(tm)); + define_macro("__TIME__", format_time(tm)); +} + +typedef enum { + STR_NONE, STR_UTF8, STR_UTF16, STR_UTF32, STR_WIDE, +} StringKind; + +static StringKind getStringKind(Token *tok) { + if (!strcmp(tok->loc, "u8")) + return STR_UTF8; + + switch (tok->loc[0]) { + case '"': return STR_NONE; + case 'u': return STR_UTF16; + case 'U': return STR_UTF32; + case 'L': return STR_WIDE; + } + unreachable(); +} + +// Concatenate adjacent string literals into a single string literal +// as per the C spec. +static void join_adjacent_string_literals(Token *tok) { + // First pass: If regular string literals are adjacent to wide + // string literals, regular string literals are converted to a wide + // type before concatenation. In this pass, we do the conversion. + for (Token *tok1 = tok; tok1->kind != TK_EOF;) { + if (tok1->kind != TK_STR || tok1->next->kind != TK_STR) { + tok1 = tok1->next; + continue; + } + + StringKind kind = getStringKind(tok1); + Type *basety = tok1->ty->base; + + for (Token *t = tok1->next; t->kind == TK_STR; t = t->next) { + StringKind k = getStringKind(t); + if (kind == STR_NONE) { + kind = k; + basety = t->ty->base; + } else if (k != STR_NONE && kind != k) { + error_tok(t, "unsupported non-standard concatenation of string literals"); + } + } + + if (basety->size > 1) + for (Token *t = tok1; t->kind == TK_STR; t = t->next) + if (t->ty->base->size == 1) + *t = *tokenize_string_literal(t, basety); + + while (tok1->kind == TK_STR) + tok1 = tok1->next; + } + + // Second pass: concatenate adjacent string literals. + for (Token *tok1 = tok; tok1->kind != TK_EOF;) { + if (tok1->kind != TK_STR || tok1->next->kind != TK_STR) { + tok1 = tok1->next; + continue; + } + + Token *tok2 = tok1->next; + while (tok2->kind == TK_STR) + tok2 = tok2->next; + + int len = tok1->ty->array_len; + for (Token *t = tok1->next; t != tok2; t = t->next) + len = len + t->ty->array_len - 1; + + char *buf = calloc(tok1->ty->base->size, len); + + int i = 0; + for (Token *t = tok1; t != tok2; t = t->next) { + memcpy(buf + i, t->str, t->ty->size); + i = i + t->ty->size - t->ty->base->size; + } + + *tok1 = *copy_token(tok1); + tok1->ty = array_of(tok1->ty->base, len); + tok1->str = buf; + tok1->next = tok2; + tok1 = tok2; + } +} + +// Entry point function of the preprocessor. +Token *preprocess(Token *tok) { + tok = preprocess2(tok); + if (cond_incl) + error_tok(cond_incl->tok, "unterminated conditional directive"); + convert_pp_tokens(tok); + join_adjacent_string_literals(tok); + + for (Token *t = tok; t; t = t->next) + t->line_no += t->line_delta; + return tok; +} diff --git a/src/3p/chibicc/strings.c b/src/3p/chibicc/strings.c new file mode 100644 index 0000000..0538fef --- /dev/null +++ b/src/3p/chibicc/strings.c @@ -0,0 +1,17 @@ +#include "chibicc.h" + +void strarray_push(StringArray *arr, char *s) { + if (!arr->data) { + arr->data = calloc(8, sizeof(char *)); + arr->capacity = 8; + } + + if (arr->capacity == arr->len) { + arr->data = realloc(arr->data, sizeof(char *) * arr->capacity * 2); + arr->capacity *= 2; + for (int i = arr->len; i < arr->capacity; i++) + arr->data[i] = NULL; + } + + arr->data[arr->len++] = s; +} diff --git a/src/3p/chibicc/tokenize.c b/src/3p/chibicc/tokenize.c new file mode 100644 index 0000000..8ed414e --- /dev/null +++ b/src/3p/chibicc/tokenize.c @@ -0,0 +1,799 @@ +#include "chibicc.h" + +// Input file +static File *current_file; + +// A list of all input files. +static File **input_files; + +// True if the current position is at the beginning of a line +static bool at_bol; + +// True if the current position follows a space character +static bool has_space; + +// Reports an error and exit. +void error(char *fmt, ...) { + va_list ap; + va_start(ap, fmt); + fprintf(stderr, "cmeta: chibicc: "); + vfprintf(stderr, fmt, ap); + fprintf(stderr, "\n"); + exit(1); +} + +// Reports an error message in the following format. +// +// foo.c:10: x = y + 1; +// ^ +static void verror_at(char *filename, char *input, int line_no, + char *loc, char *fmt, va_list ap) { + // Find a line containing `loc`. + char *line = loc; + while (input < line && line[-1] != '\n') + line--; + + char *end = loc; + while (*end && *end != '\n') + end++; + + // Print out the line. + int indent = fprintf(stderr, "%s:%d: ", filename, line_no); + fprintf(stderr, "%.*s\n", (int)(end - line), line); + + // Show the error message. + int pos = display_width(line, loc - line) + indent; + + fprintf(stderr, "%*s", pos, ""); // print pos spaces. + fprintf(stderr, "^ "); + vfprintf(stderr, fmt, ap); + fprintf(stderr, "\n"); +} + +void error_at(char *loc, char *fmt, ...) { + int line_no = 1; + for (char *p = current_file->contents; p < loc; p++) + if (*p == '\n') + line_no++; + + va_list ap; + va_start(ap, fmt); + verror_at(current_file->name, current_file->contents, line_no, loc, fmt, ap); + exit(1); +} + +void error_tok(Token *tok, char *fmt, ...) { + va_list ap; + va_start(ap, fmt); + verror_at(tok->file->name, tok->file->contents, tok->line_no, tok->loc, fmt, ap); + exit(1); +} + +void warn_tok(Token *tok, char *fmt, ...) { + va_list ap; + va_start(ap, fmt); + verror_at(tok->file->name, tok->file->contents, tok->line_no, tok->loc, fmt, ap); + va_end(ap); +} + +// Consumes the current token if it matches `op`. +bool equal(Token *tok, char *op) { + return memcmp(tok->loc, op, tok->len) == 0 && op[tok->len] == '\0'; +} + +// Ensure that the current token is `op`. +Token *skip(Token *tok, char *op) { + if (!equal(tok, op)) + error_tok(tok, "expected '%s'", op); + return tok->next; +} + +bool consume(Token **rest, Token *tok, char *str) { + if (equal(tok, str)) { + *rest = tok->next; + return true; + } + *rest = tok; + return false; +} + +// Create a new token. +static Token *new_token(TokenKind kind, char *start, char *end) { + Token *tok = calloc(1, sizeof(Token)); + tok->kind = kind; + tok->loc = start; + tok->len = end - start; + tok->file = current_file; + tok->filename = current_file->display_name; + tok->at_bol = at_bol; + tok->has_space = has_space; + + at_bol = has_space = false; + return tok; +} + +static bool startswith(char *p, char *q) { + return strncmp(p, q, strlen(q)) == 0; +} + +// Read an identifier and returns the length of it. +// If p does not point to a valid identifier, 0 is returned. +static int read_ident(char *start) { + char *p = start; + uint32_t c = decode_utf8(&p, p); + if (!is_ident1(c)) + return 0; + + for (;;) { + char *q; + c = decode_utf8(&q, p); + if (!is_ident2(c)) + return p - start; + p = q; + } +} + +static int from_hex(char c) { + if ('0' <= c && c <= '9') + return c - '0'; + if ('a' <= c && c <= 'f') + return c - 'a' + 10; + return c - 'A' + 10; +} + +// Read a punctuator token from p and returns its length. +static int read_punct(char *p) { + static char *kw[] = { + "<<=", ">>=", "...", "==", "!=", "<=", ">=", "->", "+=", + "-=", "*=", "/=", "++", "--", "%=", "&=", "|=", "^=", "&&", + "||", "<<", ">>", "##", + }; + + for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++) + if (startswith(p, kw[i])) + return strlen(kw[i]); + + return ispunct(*p) ? 1 : 0; +} + +static bool is_keyword(Token *tok) { + static HashMap map; + + if (map.capacity == 0) { + static char *kw[] = { + "return", "if", "else", "for", "while", "int", "sizeof", "char", + "struct", "union", "short", "long", "void", "typedef", "_Bool", + "enum", "static", "goto", "break", "continue", "switch", "case", + "default", "extern", "_Alignof", "_Alignas", "do", "signed", + "unsigned", "const", "volatile", "auto", "register", "restrict", + "__restrict", "__restrict__", "_Noreturn", "float", "double", + "typeof", "asm", "_Thread_local", "__thread", "_Atomic", + "__attribute__", + }; + + for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++) + hashmap_put(&map, kw[i], (void *)1); + } + + return hashmap_get2(&map, tok->loc, tok->len); +} + +static int read_escaped_char(char **new_pos, char *p) { + if ('0' <= *p && *p <= '7') { + // Read an octal number. + int c = *p++ - '0'; + if ('0' <= *p && *p <= '7') { + c = (c << 3) + (*p++ - '0'); + if ('0' <= *p && *p <= '7') + c = (c << 3) + (*p++ - '0'); + } + *new_pos = p; + return c; + } + + if (*p == 'x') { + // Read a hexadecimal number. + p++; + if (!isxdigit(*p)) + error_at(p, "invalid hex escape sequence"); + + int c = 0; + for (; isxdigit(*p); p++) + c = (c << 4) + from_hex(*p); + *new_pos = p; + return c; + } + + *new_pos = p + 1; + + // Escape sequences are defined using themselves here. E.g. + // '\n' is implemented using '\n'. This tautological definition + // works because the compiler that compiles our compiler knows + // what '\n' actually is. In other words, we "inherit" the ASCII + // code of '\n' from the compiler that compiles our compiler, + // so we don't have to teach the actual code here. + // + // This fact has huge implications not only for the correctness + // of the compiler but also for the security of the generated code. + // For more info, read "Reflections on Trusting Trust" by Ken Thompson. + // https://github.com/rui314/chibicc/wiki/thompson1984.pdf + switch (*p) { + case 'a': return '\a'; + case 'b': return '\b'; + case 't': return '\t'; + case 'n': return '\n'; + case 'v': return '\v'; + case 'f': return '\f'; + case 'r': return '\r'; + // [GNU] \e for the ASCII escape character is a GNU C extension. + case 'e': return 27; + default: return *p; + } +} + +// Find a closing double-quote. +static char *string_literal_end(char *p) { + char *start = p; + for (; *p != '"'; p++) { + if (*p == '\n' || *p == '\0') + error_at(start, "unclosed string literal"); + if (*p == '\\') + p++; + } + return p; +} + +static Token *read_string_literal(char *start, char *quote) { + char *end = string_literal_end(quote + 1); + char *buf = calloc(1, end - quote); + int len = 0; + + for (char *p = quote + 1; p < end;) { + if (*p == '\\') + buf[len++] = read_escaped_char(&p, p + 1); + else + buf[len++] = *p++; + } + + Token *tok = new_token(TK_STR, start, end + 1); + tok->ty = array_of(ty_char, len + 1); + tok->str = buf; + return tok; +} + +// Read a UTF-8-encoded string literal and transcode it in UTF-16. +// +// UTF-16 is yet another variable-width encoding for Unicode. Code +// points smaller than U+10000 are encoded in 2 bytes. Code points +// equal to or larger than that are encoded in 4 bytes. Each 2 bytes +// in the 4 byte sequence is called "surrogate", and a 4 byte sequence +// is called a "surrogate pair". +static Token *read_utf16_string_literal(char *start, char *quote) { + char *end = string_literal_end(quote + 1); + uint16_t *buf = calloc(2, end - start); + int len = 0; + + for (char *p = quote + 1; p < end;) { + if (*p == '\\') { + buf[len++] = read_escaped_char(&p, p + 1); + continue; + } + + uint32_t c = decode_utf8(&p, p); + if (c < 0x10000) { + // Encode a code point in 2 bytes. + buf[len++] = c; + } else { + // Encode a code point in 4 bytes. + c -= 0x10000; + buf[len++] = 0xd800 + ((c >> 10) & 0x3ff); + buf[len++] = 0xdc00 + (c & 0x3ff); + } + } + + Token *tok = new_token(TK_STR, start, end + 1); + tok->ty = array_of(ty_ushort, len + 1); + tok->str = (char *)buf; + return tok; +} + +// Read a UTF-8-encoded string literal and transcode it in UTF-32. +// +// UTF-32 is a fixed-width encoding for Unicode. Each code point is +// encoded in 4 bytes. +static Token *read_utf32_string_literal(char *start, char *quote, Type *ty) { + char *end = string_literal_end(quote + 1); + uint32_t *buf = calloc(4, end - quote); + int len = 0; + + for (char *p = quote + 1; p < end;) { + if (*p == '\\') + buf[len++] = read_escaped_char(&p, p + 1); + else + buf[len++] = decode_utf8(&p, p); + } + + Token *tok = new_token(TK_STR, start, end + 1); + tok->ty = array_of(ty, len + 1); + tok->str = (char *)buf; + return tok; +} + +static Token *read_char_literal(char *start, char *quote, Type *ty) { + char *p = quote + 1; + if (*p == '\0') + error_at(start, "unclosed char literal"); + + int c; + if (*p == '\\') + c = read_escaped_char(&p, p + 1); + else + c = decode_utf8(&p, p); + + char *end = strchr(p, '\''); + if (!end) + error_at(p, "unclosed char literal"); + + Token *tok = new_token(TK_NUM, start, end + 1); + tok->val = c; + tok->ty = ty; + return tok; +} + +static bool convert_pp_int(Token *tok) { + char *p = tok->loc; + + // Read a binary, octal, decimal or hexadecimal number. + int base = 10; + if (!strncasecmp(p, "0x", 2) && isxdigit(p[2])) { + p += 2; + base = 16; + } else if (!strncasecmp(p, "0b", 2) && (p[2] == '0' || p[2] == '1')) { + p += 2; + base = 2; + } else if (*p == '0') { + base = 8; + } + + int64_t val = strtoul(p, &p, base); + + // Read U, L or LL suffixes. + bool l = false; + bool u = false; + + if (startswith(p, "LLU") || startswith(p, "LLu") || + startswith(p, "llU") || startswith(p, "llu") || + startswith(p, "ULL") || startswith(p, "Ull") || + startswith(p, "uLL") || startswith(p, "ull")) { + p += 3; + l = u = true; + } else if (!strncasecmp(p, "lu", 2) || !strncasecmp(p, "ul", 2)) { + p += 2; + l = u = true; + } else if (startswith(p, "LL") || startswith(p, "ll")) { + p += 2; + l = true; + } else if (*p == 'L' || *p == 'l') { + p++; + l = true; + } else if (*p == 'U' || *p == 'u') { + p++; + u = true; + } + + if (p != tok->loc + tok->len) + return false; + + // Infer a type. + Type *ty; + if (base == 10) { + if (l && u) + ty = ty_ulong; + else if (l) + ty = ty_long; + else if (u) + ty = (val >> 32) ? ty_ulong : ty_uint; + else + ty = (val >> 31) ? ty_long : ty_int; + } else { + if (l && u) + ty = ty_ulong; + else if (l) + ty = (val >> 63) ? ty_ulong : ty_long; + else if (u) + ty = (val >> 32) ? ty_ulong : ty_uint; + else if (val >> 63) + ty = ty_ulong; + else if (val >> 32) + ty = ty_long; + else if (val >> 31) + ty = ty_uint; + else + ty = ty_int; + } + + tok->kind = TK_NUM; + tok->val = val; + tok->ty = ty; + return true; +} + +// The definition of the numeric literal at the preprocessing stage +// is more relaxed than the definition of that at the later stages. +// In order to handle that, a numeric literal is tokenized as a +// "pp-number" token first and then converted to a regular number +// token after preprocessing. +// +// This function converts a pp-number token to a regular number token. +static void convert_pp_number(Token *tok) { + // Try to parse as an integer constant. + if (convert_pp_int(tok)) + return; + + // If it's not an integer, it must be a floating point constant. + char *end; + long double val = strtold(tok->loc, &end); + + Type *ty; + if (*end == 'f' || *end == 'F') { + ty = ty_float; + end++; + } else if (*end == 'l' || *end == 'L') { + ty = ty_ldouble; + end++; + } else { + ty = ty_double; + } + + if (tok->loc + tok->len != end) + error_tok(tok, "invalid numeric constant"); + + tok->kind = TK_NUM; + tok->fval = val; + tok->ty = ty; +} + +void convert_pp_tokens(Token *tok) { + for (Token *t = tok; t->kind != TK_EOF; t = t->next) { + if (is_keyword(t)) + t->kind = TK_KEYWORD; + else if (t->kind == TK_PP_NUM) + convert_pp_number(t); + } +} + +// Initialize line info for all tokens. +static void add_line_numbers(Token *tok) { + char *p = current_file->contents; + int n = 1; + + do { + if (p == tok->loc) { + tok->line_no = n; + tok = tok->next; + } + if (*p == '\n') + n++; + } while (*p++); +} + +Token *tokenize_string_literal(Token *tok, Type *basety) { + Token *t; + if (basety->size == 2) + t = read_utf16_string_literal(tok->loc, tok->loc); + else + t = read_utf32_string_literal(tok->loc, tok->loc, basety); + t->next = tok->next; + return t; +} + +// Tokenize a given string and returns new tokens. +Token *tokenize(File *file) { + current_file = file; + + char *p = file->contents; + Token head = {0}; + Token *cur = &head; + + at_bol = true; + has_space = false; + + while (*p) { + // Skip line comments. + if (startswith(p, "//")) { + p += 2; + while (*p != '\n') + p++; + has_space = true; + continue; + } + + // Skip block comments. + if (startswith(p, "/*")) { + char *q = strstr(p + 2, "*/"); + if (!q) + error_at(p, "unclosed block comment"); + p = q + 2; + has_space = true; + continue; + } + + // Skip newline. + if (*p == '\n') { + p++; + at_bol = true; + has_space = false; + continue; + } + + // Skip whitespace characters. + if (isspace(*p)) { + p++; + has_space = true; + continue; + } + + // Numeric literal + if (isdigit(*p) || (*p == '.' && isdigit(p[1]))) { + char *q = p++; + for (;;) { + if (p[0] && p[1] && strchr("eEpP", p[0]) && strchr("+-", p[1])) + p += 2; + else if (isalnum(*p) || *p == '.') + p++; + else + break; + } + cur = cur->next = new_token(TK_PP_NUM, q, p); + continue; + } + + // String literal + if (*p == '"') { + cur = cur->next = read_string_literal(p, p); + p += cur->len; + continue; + } + + // UTF-8 string literal + if (startswith(p, "u8\"")) { + cur = cur->next = read_string_literal(p, p + 2); + p += cur->len; + continue; + } + + // UTF-16 string literal + if (startswith(p, "u\"")) { + cur = cur->next = read_utf16_string_literal(p, p + 1); + p += cur->len; + continue; + } + + // Wide string literal + if (startswith(p, "L\"")) { + cur = cur->next = read_utf32_string_literal(p, p + 1, ty_int); + p += cur->len; + continue; + } + + // UTF-32 string literal + if (startswith(p, "U\"")) { + cur = cur->next = read_utf32_string_literal(p, p + 1, ty_uint); + p += cur->len; + continue; + } + + // Character literal + if (*p == '\'') { + cur = cur->next = read_char_literal(p, p, ty_int); + cur->val = (char)cur->val; + p += cur->len; + continue; + } + + // UTF-16 character literal + if (startswith(p, "u'")) { + cur = cur->next = read_char_literal(p, p + 1, ty_ushort); + cur->val &= 0xffff; + p += cur->len; + continue; + } + + // Wide character literal + if (startswith(p, "L'")) { + cur = cur->next = read_char_literal(p, p + 1, ty_int); + p += cur->len; + continue; + } + + // UTF-32 character literal + if (startswith(p, "U'")) { + cur = cur->next = read_char_literal(p, p + 1, ty_uint); + p += cur->len; + continue; + } + + // Identifier or keyword + int ident_len = read_ident(p); + if (ident_len) { + cur = cur->next = new_token(TK_IDENT, p, p + ident_len); + p += cur->len; + continue; + } + + // Punctuators + int punct_len = read_punct(p); + if (punct_len) { + cur = cur->next = new_token(TK_PUNCT, p, p + punct_len); + p += cur->len; + continue; + } + + error_at(p, "invalid token"); + } + + cur = cur->next = new_token(TK_EOF, p, p); + add_line_numbers(head.next); + return head.next; +} + +// Returns the contents of a given file. +/* this function is a bit wonkily implemented, and relies on a non-windows + * thing, so we have our own in src/cmeta.c. +static char *read_file(char *path) { + FILE *fp; + + if (strcmp(path, "-") == 0) { + // By convention, read from stdin if a given filename is "-". + fp = stdin; + } else { + fp = fopen(path, "r"); + if (!fp) + return NULL; + } + + char *buf; + size_t buflen; + FILE *out = open_memstream(&buf, &buflen); + + // Read the entire file. + for (;;) { + char buf2[4096]; + int n = fread(buf2, 1, sizeof(buf2), fp); + if (n == 0) + break; + fwrite(buf2, 1, n, out); + } + + if (fp != stdin) + fclose(fp); + + // Make sure that the last line is properly terminated with '\n'. + fflush(out); + if (buflen == 0 || buf[buflen - 1] != '\n') + fputc('\n', out); + fputc('\0', out); + fclose(out); + return buf; +} +*/ + +File **get_input_files(void) { + return input_files; +} + +File *new_file(char *name, int file_no, char *contents) { + File *file = calloc(1, sizeof(File)); + file->name = name; + file->display_name = name; + file->file_no = file_no; + file->contents = contents; + return file; +} + +// Replaces \r or \r\n with \n. +static void canonicalize_newline(char *p) { + int i = 0, j = 0; + + while (p[i]) { + if (p[i] == '\r' && p[i + 1] == '\n') { + i += 2; + p[j++] = '\n'; + } else if (p[i] == '\r') { + i++; + p[j++] = '\n'; + } else { + p[j++] = p[i++]; + } + } + + p[j] = '\0'; +} + +// Removes backslashes followed by a newline. +static void remove_backslash_newline(char *p) { + int i = 0, j = 0; + + // We want to keep the number of newline characters so that + // the logical line number matches the physical one. + // This counter maintain the number of newlines we have removed. + int n = 0; + + while (p[i]) { + if (p[i] == '\\' && p[i + 1] == '\n') { + i += 2; + n++; + } else if (p[i] == '\n') { + p[j++] = p[i++]; + for (; n > 0; n--) + p[j++] = '\n'; + } else { + p[j++] = p[i++]; + } + } + + for (; n > 0; n--) + p[j++] = '\n'; + p[j] = '\0'; +} + +static uint32_t read_universal_char(char *p, int len) { + uint32_t c = 0; + for (int i = 0; i < len; i++) { + if (!isxdigit(p[i])) + return 0; + c = (c << 4) | from_hex(p[i]); + } + return c; +} + +// Replace \u or \U escape sequences with corresponding UTF-8 bytes. +static void convert_universal_chars(char *p) { + char *q = p; + + while (*p) { + if (startswith(p, "\\u")) { + uint32_t c = read_universal_char(p + 2, 4); + if (c) { + p += 6; + q += encode_utf8(q, c); + } else { + *q++ = *p++; + } + } else if (startswith(p, "\\U")) { + uint32_t c = read_universal_char(p + 2, 8); + if (c) { + p += 10; + q += encode_utf8(q, c); + } else { + *q++ = *p++; + } + } else if (p[0] == '\\') { + *q++ = *p++; + *q++ = *p++; + } else { + *q++ = *p++; + } + } + + *q = '\0'; +} + +// NOTE modified API from upstream +Token *tokenize_buf(const char *name, char *p) { + canonicalize_newline(p); + remove_backslash_newline(p); + convert_universal_chars(p); + + // Save the filename for assembler .file directive. + static int file_no; + File *file = new_file((char *)name, file_no + 1, p); + + // Save the filename for assembler .file directive. + input_files = realloc(input_files, sizeof(char *) * (file_no + 2)); + input_files[file_no] = file; + input_files[file_no + 1] = NULL; + file_no++; + + return tokenize(file); +} diff --git a/src/3p/chibicc/type.c b/src/3p/chibicc/type.c new file mode 100644 index 0000000..02ade59 --- /dev/null +++ b/src/3p/chibicc/type.c @@ -0,0 +1,307 @@ +#include "chibicc.h" + +Type *ty_void = &(Type){TY_VOID, 1, 1}; +Type *ty_bool = &(Type){TY_BOOL, 1, 1}; + +Type *ty_char = &(Type){TY_CHAR, 1, 1}; +Type *ty_short = &(Type){TY_SHORT, 2, 2}; +Type *ty_int = &(Type){TY_INT, 4, 4}; +Type *ty_long = &(Type){TY_LONG, 8, 8}; + +Type *ty_uchar = &(Type){TY_CHAR, 1, 1, true}; +Type *ty_ushort = &(Type){TY_SHORT, 2, 2, true}; +Type *ty_uint = &(Type){TY_INT, 4, 4, true}; +Type *ty_ulong = &(Type){TY_LONG, 8, 8, true}; + +Type *ty_float = &(Type){TY_FLOAT, 4, 4}; +Type *ty_double = &(Type){TY_DOUBLE, 8, 8}; +Type *ty_ldouble = &(Type){TY_LDOUBLE, 16, 16}; + +static Type *new_type(TypeKind kind, int size, int align) { + Type *ty = calloc(1, sizeof(Type)); + ty->kind = kind; + ty->size = size; + ty->align = align; + return ty; +} + +bool is_integer(Type *ty) { + TypeKind k = ty->kind; + return k == TY_BOOL || k == TY_CHAR || k == TY_SHORT || + k == TY_INT || k == TY_LONG || k == TY_ENUM; +} + +bool is_flonum(Type *ty) { + return ty->kind == TY_FLOAT || ty->kind == TY_DOUBLE || + ty->kind == TY_LDOUBLE; +} + +bool is_numeric(Type *ty) { + return is_integer(ty) || is_flonum(ty); +} + +bool is_compatible(Type *t1, Type *t2) { + if (t1 == t2) + return true; + + if (t1->origin) + return is_compatible(t1->origin, t2); + + if (t2->origin) + return is_compatible(t1, t2->origin); + + if (t1->kind != t2->kind) + return false; + + switch (t1->kind) { + case TY_CHAR: + case TY_SHORT: + case TY_INT: + case TY_LONG: + return t1->is_unsigned == t2->is_unsigned; + case TY_FLOAT: + case TY_DOUBLE: + case TY_LDOUBLE: + return true; + case TY_PTR: + return is_compatible(t1->base, t2->base); + case TY_FUNC: { + if (!is_compatible(t1->return_ty, t2->return_ty)) + return false; + if (t1->is_variadic != t2->is_variadic) + return false; + + Type *p1 = t1->params; + Type *p2 = t2->params; + for (; p1 && p2; p1 = p1->next, p2 = p2->next) + if (!is_compatible(p1, p2)) + return false; + return p1 == NULL && p2 == NULL; + } + case TY_ARRAY: + if (!is_compatible(t1->base, t2->base)) + return false; + return t1->array_len < 0 && t2->array_len < 0 && + t1->array_len == t2->array_len; + } + return false; +} + +Type *copy_type(Type *ty) { + Type *ret = calloc(1, sizeof(Type)); + *ret = *ty; + ret->origin = ty; + return ret; +} + +Type *pointer_to(Type *base) { + Type *ty = new_type(TY_PTR, 8, 8); + ty->base = base; + ty->is_unsigned = true; + return ty; +} + +Type *func_type(Type *return_ty) { + // The C spec disallows sizeof(), but + // GCC allows that and the expression is evaluated to 1. + Type *ty = new_type(TY_FUNC, 1, 1); + ty->return_ty = return_ty; + return ty; +} + +Type *array_of(Type *base, int len) { + Type *ty = new_type(TY_ARRAY, base->size * len, base->align); + ty->base = base; + ty->array_len = len; + return ty; +} + +Type *vla_of(Type *base, Node *len) { + Type *ty = new_type(TY_VLA, 8, 8); + ty->base = base; + ty->vla_len = len; + return ty; +} + +Type *enum_type(void) { + return new_type(TY_ENUM, 4, 4); +} + +Type *struct_type(void) { + return new_type(TY_STRUCT, 0, 1); +} + +static Type *get_common_type(Type *ty1, Type *ty2) { + if (ty1->base) + return pointer_to(ty1->base); + + if (ty1->kind == TY_FUNC) + return pointer_to(ty1); + if (ty2->kind == TY_FUNC) + return pointer_to(ty2); + + if (ty1->kind == TY_LDOUBLE || ty2->kind == TY_LDOUBLE) + return ty_ldouble; + if (ty1->kind == TY_DOUBLE || ty2->kind == TY_DOUBLE) + return ty_double; + if (ty1->kind == TY_FLOAT || ty2->kind == TY_FLOAT) + return ty_float; + + if (ty1->size < 4) + ty1 = ty_int; + if (ty2->size < 4) + ty2 = ty_int; + + if (ty1->size != ty2->size) + return (ty1->size < ty2->size) ? ty2 : ty1; + + if (ty2->is_unsigned) + return ty2; + return ty1; +} + +// For many binary operators, we implicitly promote operands so that +// both operands have the same type. Any integral type smaller than +// int is always promoted to int. If the type of one operand is larger +// than the other's (e.g. "long" vs. "int"), the smaller operand will +// be promoted to match with the other. +// +// This operation is called the "usual arithmetic conversion". +static void usual_arith_conv(Node **lhs, Node **rhs) { + Type *ty = get_common_type((*lhs)->ty, (*rhs)->ty); + *lhs = new_cast(*lhs, ty); + *rhs = new_cast(*rhs, ty); +} + +void add_type(Node *node) { + if (!node || node->ty) + return; + + add_type(node->lhs); + add_type(node->rhs); + add_type(node->cond); + add_type(node->then); + add_type(node->els); + add_type(node->init); + add_type(node->inc); + + for (Node *n = node->body; n; n = n->next) + add_type(n); + for (Node *n = node->args; n; n = n->next) + add_type(n); + + switch (node->kind) { + case ND_NUM: + node->ty = ty_int; + return; + case ND_ADD: + case ND_SUB: + case ND_MUL: + case ND_DIV: + case ND_MOD: + case ND_BITAND: + case ND_BITOR: + case ND_BITXOR: + usual_arith_conv(&node->lhs, &node->rhs); + node->ty = node->lhs->ty; + return; + case ND_NEG: { + Type *ty = get_common_type(ty_int, node->lhs->ty); + node->lhs = new_cast(node->lhs, ty); + node->ty = ty; + return; + } + case ND_ASSIGN: + if (node->lhs->ty->kind == TY_ARRAY) + error_tok(node->lhs->tok, "not an lvalue"); + if (node->lhs->ty->kind != TY_STRUCT) + node->rhs = new_cast(node->rhs, node->lhs->ty); + node->ty = node->lhs->ty; + return; + case ND_EQ: + case ND_NE: + case ND_LT: + case ND_LE: + usual_arith_conv(&node->lhs, &node->rhs); + node->ty = ty_int; + return; + case ND_FUNCALL: + node->ty = node->func_ty->return_ty; + return; + case ND_NOT: + case ND_LOGOR: + case ND_LOGAND: + node->ty = ty_int; + return; + case ND_BITNOT: + case ND_SHL: + case ND_SHR: + node->ty = node->lhs->ty; + return; + case ND_VAR: + case ND_VLA_PTR: + node->ty = node->var->ty; + return; + case ND_COND: + if (node->then->ty->kind == TY_VOID || node->els->ty->kind == TY_VOID) { + node->ty = ty_void; + } else { + usual_arith_conv(&node->then, &node->els); + node->ty = node->then->ty; + } + return; + case ND_COMMA: + node->ty = node->rhs->ty; + return; + case ND_MEMBER: + node->ty = node->member->ty; + return; + case ND_ADDR: { + Type *ty = node->lhs->ty; + if (ty->kind == TY_ARRAY) + node->ty = pointer_to(ty->base); + else + node->ty = pointer_to(ty); + return; + } + case ND_DEREF: + if (!node->lhs->ty->base) + error_tok(node->tok, "invalid pointer dereference"); + if (node->lhs->ty->base->kind == TY_VOID) + error_tok(node->tok, "dereferencing a void pointer"); + + node->ty = node->lhs->ty->base; + return; + case ND_STMT_EXPR: + if (node->body) { + Node *stmt = node->body; + while (stmt->next) + stmt = stmt->next; + if (stmt->kind == ND_EXPR_STMT) { + node->ty = stmt->lhs->ty; + return; + } + } + error_tok(node->tok, "statement expression returning void is not supported"); + return; + case ND_LABEL_VAL: + node->ty = pointer_to(ty_void); + return; + case ND_CAS: + add_type(node->cas_addr); + add_type(node->cas_old); + add_type(node->cas_new); + node->ty = ty_bool; + + if (node->cas_addr->ty->kind != TY_PTR) + error_tok(node->cas_addr->tok, "pointer expected"); + if (node->cas_old->ty->kind != TY_PTR) + error_tok(node->cas_old->tok, "pointer expected"); + return; + case ND_EXCH: + if (node->lhs->ty->kind != TY_PTR) + error_tok(node->cas_addr->tok, "pointer expected"); + node->ty = node->lhs->ty->base; + return; + } +} diff --git a/src/3p/chibicc/unicode.c b/src/3p/chibicc/unicode.c new file mode 100644 index 0000000..6db1ad7 --- /dev/null +++ b/src/3p/chibicc/unicode.c @@ -0,0 +1,189 @@ +#include "chibicc.h" + +// Encode a given character in UTF-8. +int encode_utf8(char *buf, uint32_t c) { + if (c <= 0x7F) { + buf[0] = c; + return 1; + } + + if (c <= 0x7FF) { + buf[0] = 0xC0 | (c >> 6); + buf[1] = 0x80 | ((c >> 6) & 0x3F); + return 2; + } + + if (c <= 0xFFFF) { + buf[0] = 0xE0 | (c >> 12); + buf[1] = 0x80 | ((c >> 6) & 0x3F); + buf[2] = 0x80 | (c & 0x3F); + return 3; + } + + buf[0] = 0xF0 | (c >> 18); + buf[1] = 0x80 | ((c >> 12) & 0x3F); + buf[2] = 0x80 | ((c >> 6) & 0x3F); + buf[3] = 0x80 | (c & 0x3F); + return 4; +} + +// Read a UTF-8-encoded Unicode code point from a source file. +// We assume that source files are always in UTF-8. +// +// UTF-8 is a variable-width encoding in which one code point is +// encoded in one to four bytes. One byte UTF-8 code points are +// identical to ASCII. Non-ASCII characters are encoded using more +// than one byte. +uint32_t decode_utf8(char **new_pos, char *p) { + if ((unsigned char)*p < 128) { + *new_pos = p + 1; + return *p; + } + + char *start = p; + int len; + uint32_t c; + + if ((unsigned char)*p >= 0xF0) { + len = 4; + c = *p & 7; + } else if ((unsigned char)*p >= 0xE0) { + len = 3; + c = *p & 15; + } else if ((unsigned char)*p >= 0xC0) { + len = 2; + c = *p & 31; + } else { + error_at(start, "invalid UTF-8 sequence"); + } + + for (int i = 1; i < len; i++) { + if ((unsigned char)p[i] >> 6 != 2) + error_at(start, "invalid UTF-8 sequence"); + c = (c << 6) | (p[i] & 63); + } + + *new_pos = p + len; + return c; +} + +static bool in_range(uint32_t *range, uint32_t c) { + for (int i = 0; range[i] != -1; i += 2) + if (range[i] <= c && c <= range[i + 1]) + return true; + return false; +} + +// [https://www.sigbus.info/n1570#D] C11 allows not only ASCII but +// some multibyte characters in certan Unicode ranges to be used in an +// identifier. +// +// This function returns true if a given character is acceptable as +// the first character of an identifier. +// +// For example, ¾ (U+00BE) is a valid identifier because characters in +// 0x00BE-0x00C0 are allowed, while neither ⟘ (U+27D8) nor '　' +// (U+3000, full-width space) are allowed because they are out of range. +bool is_ident1(uint32_t c) { + static uint32_t range[] = { + '_', '_', 'a', 'z', 'A', 'Z', '$', '$', + 0x00A8, 0x00A8, 0x00AA, 0x00AA, 0x00AD, 0x00AD, 0x00AF, 0x00AF, + 0x00B2, 0x00B5, 0x00B7, 0x00BA, 0x00BC, 0x00BE, 0x00C0, 0x00D6, + 0x00D8, 0x00F6, 0x00F8, 0x00FF, 0x0100, 0x02FF, 0x0370, 0x167F, + 0x1681, 0x180D, 0x180F, 0x1DBF, 0x1E00, 0x1FFF, 0x200B, 0x200D, + 0x202A, 0x202E, 0x203F, 0x2040, 0x2054, 0x2054, 0x2060, 0x206F, + 0x2070, 0x20CF, 0x2100, 0x218F, 0x2460, 0x24FF, 0x2776, 0x2793, + 0x2C00, 0x2DFF, 0x2E80, 0x2FFF, 0x3004, 0x3007, 0x3021, 0x302F, + 0x3031, 0x303F, 0x3040, 0xD7FF, 0xF900, 0xFD3D, 0xFD40, 0xFDCF, + 0xFDF0, 0xFE1F, 0xFE30, 0xFE44, 0xFE47, 0xFFFD, + 0x10000, 0x1FFFD, 0x20000, 0x2FFFD, 0x30000, 0x3FFFD, 0x40000, 0x4FFFD, + 0x50000, 0x5FFFD, 0x60000, 0x6FFFD, 0x70000, 0x7FFFD, 0x80000, 0x8FFFD, + 0x90000, 0x9FFFD, 0xA0000, 0xAFFFD, 0xB0000, 0xBFFFD, 0xC0000, 0xCFFFD, + 0xD0000, 0xDFFFD, 0xE0000, 0xEFFFD, -1, + }; + + return in_range(range, c); +} + +// Returns true if a given character is acceptable as a non-first +// character of an identifier. +bool is_ident2(uint32_t c) { + static uint32_t range[] = { + '0', '9', '$', '$', 0x0300, 0x036F, 0x1DC0, 0x1DFF, 0x20D0, 0x20FF, + 0xFE20, 0xFE2F, -1, + }; + + return is_ident1(c) || in_range(range, c); +} + +// Returns the number of columns needed to display a given +// character in a fixed-width font. +// +// Based on https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c +static int char_width(uint32_t c) { + static uint32_t range1[] = { + 0x0000, 0x001F, 0x007f, 0x00a0, 0x0300, 0x036F, 0x0483, 0x0486, + 0x0488, 0x0489, 0x0591, 0x05BD, 0x05BF, 0x05BF, 0x05C1, 0x05C2, + 0x05C4, 0x05C5, 0x05C7, 0x05C7, 0x0600, 0x0603, 0x0610, 0x0615, + 0x064B, 0x065E, 0x0670, 0x0670, 0x06D6, 0x06E4, 0x06E7, 0x06E8, + 0x06EA, 0x06ED, 0x070F, 0x070F, 0x0711, 0x0711, 0x0730, 0x074A, + 0x07A6, 0x07B0, 0x07EB, 0x07F3, 0x0901, 0x0902, 0x093C, 0x093C, + 0x0941, 0x0948, 0x094D, 0x094D, 0x0951, 0x0954, 0x0962, 0x0963, + 0x0981, 0x0981, 0x09BC, 0x09BC, 0x09C1, 0x09C4, 0x09CD, 0x09CD, + 0x09E2, 0x09E3, 0x0A01, 0x0A02, 0x0A3C, 0x0A3C, 0x0A41, 0x0A42, + 0x0A47, 0x0A48, 0x0A4B, 0x0A4D, 0x0A70, 0x0A71, 0x0A81, 0x0A82, + 0x0ABC, 0x0ABC, 0x0AC1, 0x0AC5, 0x0AC7, 0x0AC8, 0x0ACD, 0x0ACD, + 0x0AE2, 0x0AE3, 0x0B01, 0x0B01, 0x0B3C, 0x0B3C, 0x0B3F, 0x0B3F, + 0x0B41, 0x0B43, 0x0B4D, 0x0B4D, 0x0B56, 0x0B56, 0x0B82, 0x0B82, + 0x0BC0, 0x0BC0, 0x0BCD, 0x0BCD, 0x0C3E, 0x0C40, 0x0C46, 0x0C48, + 0x0C4A, 0x0C4D, 0x0C55, 0x0C56, 0x0CBC, 0x0CBC, 0x0CBF, 0x0CBF, + 0x0CC6, 0x0CC6, 0x0CCC, 0x0CCD, 0x0CE2, 0x0CE3, 0x0D41, 0x0D43, + 0x0D4D, 0x0D4D, 0x0DCA, 0x0DCA, 0x0DD2, 0x0DD4, 0x0DD6, 0x0DD6, + 0x0E31, 0x0E31, 0x0E34, 0x0E3A, 0x0E47, 0x0E4E, 0x0EB1, 0x0EB1, + 0x0EB4, 0x0EB9, 0x0EBB, 0x0EBC, 0x0EC8, 0x0ECD, 0x0F18, 0x0F19, + 0x0F35, 0x0F35, 0x0F37, 0x0F37, 0x0F39, 0x0F39, 0x0F71, 0x0F7E, + 0x0F80, 0x0F84, 0x0F86, 0x0F87, 0x0F90, 0x0F97, 0x0F99, 0x0FBC, + 0x0FC6, 0x0FC6, 0x102D, 0x1030, 0x1032, 0x1032, 0x1036, 0x1037, + 0x1039, 0x1039, 0x1058, 0x1059, 0x1160, 0x11FF, 0x135F, 0x135F, + 0x1712, 0x1714, 0x1732, 0x1734, 0x1752, 0x1753, 0x1772, 0x1773, + 0x17B4, 0x17B5, 0x17B7, 0x17BD, 0x17C6, 0x17C6, 0x17C9, 0x17D3, + 0x17DD, 0x17DD, 0x180B, 0x180D, 0x18A9, 0x18A9, 0x1920, 0x1922, + 0x1927, 0x1928, 0x1932, 0x1932, 0x1939, 0x193B, 0x1A17, 0x1A18, + 0x1B00, 0x1B03, 0x1B34, 0x1B34, 0x1B36, 0x1B3A, 0x1B3C, 0x1B3C, + 0x1B42, 0x1B42, 0x1B6B, 0x1B73, 0x1DC0, 0x1DCA, 0x1DFE, 0x1DFF, + 0x200B, 0x200F, 0x202A, 0x202E, 0x2060, 0x2063, 0x206A, 0x206F, + 0x20D0, 0x20EF, 0x302A, 0x302F, 0x3099, 0x309A, 0xA806, 0xA806, + 0xA80B, 0xA80B, 0xA825, 0xA826, 0xFB1E, 0xFB1E, 0xFE00, 0xFE0F, + 0xFE20, 0xFE23, 0xFEFF, 0xFEFF, 0xFFF9, 0xFFFB, 0x10A01, 0x10A03, + 0x10A05, 0x10A06, 0x10A0C, 0x10A0F, 0x10A38, 0x10A3A, 0x10A3F, 0x10A3F, + 0x1D167, 0x1D169, 0x1D173, 0x1D182, 0x1D185, 0x1D18B, 0x1D1AA, 0x1D1AD, + 0x1D242, 0x1D244, 0xE0001, 0xE0001, 0xE0020, 0xE007F, 0xE0100, 0xE01EF, + -1, + }; + + if (in_range(range1, c)) + return 0; + + static uint32_t range2[] = { + 0x1100, 0x115F, 0x2329, 0x2329, 0x232A, 0x232A, 0x2E80, 0x303E, + 0x3040, 0xA4CF, 0xAC00, 0xD7A3, 0xF900, 0xFAFF, 0xFE10, 0xFE19, + 0xFE30, 0xFE6F, 0xFF00, 0xFF60, 0xFFE0, 0xFFE6, 0x1F000, 0x1F644, + 0x20000, 0x2FFFD, 0x30000, 0x3FFFD, -1, + }; + + if (in_range(range2, c)) + return 2; + return 1; +} + +// Returns the number of columns needed to display a given +// string in a fixed-width font. +int display_width(char *p, int len) { + char *start = p; + int w = 0; + while (p - start < len) { + uint32_t c = decode_utf8(&p, p); + w += char_width(c); + } + return w; +} -- cgit v1.2.3