1 files changed, 60 insertions, 0 deletions
diff --git a/src/extmalloc.c b/src/extmalloc.c
new file mode 100644
index 0000000..9814d1b
--- /dev/null
+++ b/src/extmalloc.c
@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2021 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "intdefs.h"
+#include "vcall.h"
+
+// FIXME: this is duped from os.h because I don't want to pull in Windows.h,
+// consider splitting out the IMPORT/EXPORT defs to some other thing?
+#ifdef _WIN32
+#define IMPORT __declspec(dllimport) // only needed for variables
+#else
+#define IMPORT
+#endif
+
+// XXX: not sure if "ext" is the best naming convention? use brain later
+
+IMPORT void *g_pMemAlloc;
+
+// this interface has changed a bit between versions but thankfully the basic
+// functions we care about have always been at the start - nice and easy.
+// unfortunately though, because the debug and non-debug versions are overloads
+// and Microsoft are a bunch of crazies who decided vtable order should be
+// affected by naming (overloads are grouped, and *reversed* inside of a
+// group!?), we get this amusing ABI difference between platforms:
+#ifdef _WIN32
+DECL_VFUNC(void *, Alloc, 1, usize sz)
+DECL_VFUNC(void *, Realloc, 3, void *mem, usize sz)
+DECL_VFUNC(void, Free, 5, void *mem)
+#else
+DECL_VFUNC(void *, Alloc, 0, usize sz)
+DECL_VFUNC(void *, Realloc, 1, void *mem, usize sz)
+DECL_VFUNC(void, Free, 2, void *mem)
+#endif
+
+void *extmalloc(usize sz) {
+	return VCALL(g_pMemAlloc, Alloc, sz);
+}
+
+void *extrealloc(void *mem, usize sz) {
+	return VCALL(g_pMemAlloc, Realloc, mem, sz);
+}
+
+void extfree(void *mem) {
+	VCALL(g_pMemAlloc, Free, mem);
+}
+
+// vi: sw=4 ts=4 noet tw=80 cc=80