summaryrefslogtreecommitdiffhomepage
path: root/src/3p/chibicc/preprocess.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/3p/chibicc/preprocess.c')
-rw-r--r--src/3p/chibicc/preprocess.c1208
1 files changed, 0 insertions, 1208 deletions
diff --git a/src/3p/chibicc/preprocess.c b/src/3p/chibicc/preprocess.c
deleted file mode 100644
index cd8d1d8..0000000
--- a/src/3p/chibicc/preprocess.c
+++ /dev/null
@@ -1,1208 +0,0 @@
-// 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(&macros, 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(&macros, 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 <foo.h>
- 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(&macros, 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("<built-in>", 1, buf));
- add_macro(name, true, tok);
-}
-
-void undef_macro(char *name) {
- hashmap_delete(&macros, 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;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 05:02:29 +0000