implement "low hanging fruit" from C11

based on Gregor's patch sent to the list. includes:
- stdalign.h
- removing gets in C11 mode
- adding aligned_alloc and adjusting other functions to use it
- adding 'x' flag to fopen for exclusive mode

1 files changed, 3 insertions, 40 deletions

diff --git a/src/malloc/posix_memalign.c b/src/malloc/posix_memalign.c
index 2ae928c8..42cf2740 100644
--- a/src/malloc/posix_memalign.c
+++ b/src/malloc/posix_memalign.c
@@ -1,47 +1,10 @@
 #include <stdlib.h>
-#include <stdint.h>
 #include <errno.h>
 
-/* This function should work with most dlmalloc-like chunk bookkeeping
- * systems, but it's only guaranteed to work with the native implementation
- * used in this library. */
-
 int posix_memalign(void **res, size_t align, size_t len)
 {
-	unsigned char *mem, *new, *end;
-	size_t header, footer;
-
-	if ((align & -align & -sizeof(void *)) != align) return EINVAL;
-	if (len > SIZE_MAX - align) return ENOMEM;
-
-	if (align <= 4*sizeof(size_t)) {
-		if (!(mem = malloc(len)))
-			return errno;
-		*res = mem;
-		return 0;
-	}
-
-	if (!(mem = malloc(len + align-1)))
-		return errno;
-
-	header = ((size_t *)mem)[-1];
-	end = mem + (header & -8);
-	footer = ((size_t *)end)[-2];
-	new = (void *)((uintptr_t)mem + align-1 & -align);
-
-	if (!(header & 7)) {
-		((size_t *)new)[-2] = ((size_t *)mem)[-2] + (new-mem);
-		((size_t *)new)[-1] = ((size_t *)mem)[-1] - (new-mem);
-		*res = new;
-		return 0;
-	}
-
-	((size_t *)mem)[-1] = header&7 | new-mem;
-	((size_t *)new)[-2] = footer&7 | new-mem;
-	((size_t *)new)[-1] = header&7 | end-new;
-	((size_t *)end)[-2] = footer&7 | end-new;
-
-	if (new != mem) free(mem);
-	*res = new;
+	void *mem = aligned_alloc(align, len);
+	if (!mem) return errno;
+	*res = mem;
 	return 0;
 }