Use a function for aligned memory allocations

...instead of doing this manually.

1 files changed, 25 insertions, 0 deletions

diff --git a/libass/ass_utils.c b/libass/ass_utils.c
index 72993d7..e119c02 100644
--- a/libass/ass_utils.c
+++ b/libass/ass_utils.c
@@ -18,8 +18,10 @@
 
 #include "config.h"
 
+#include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <inttypes.h>
 #include <strings.h>
 
@@ -63,6 +65,29 @@ int has_avx2(void)
 
 #endif // ASM
 
+void *ass_aligned_alloc(size_t alignment, size_t size)
+{
+    if (alignment & (alignment - 1))
+        abort(); // not a power of 2
+    if (size >= SIZE_MAX - alignment - sizeof(void *))
+        return NULL;
+    char *allocation = malloc(size + sizeof(void *) + alignment - 1);
+    if (!allocation)
+        return NULL;
+    char *ptr = allocation + sizeof(void *);
+    unsigned int misalign = (uintptr_t)ptr & (alignment - 1);
+    if (misalign)
+        ptr += alignment - misalign;
+    *((void **)ptr - 1) = allocation;
+    return ptr;
+}
+
+void ass_aligned_free(void *ptr)
+{
+    if (ptr)
+        free(*((void **)ptr - 1));
+}
+
 int mystrtoi(char **p, int *res)
 {
     double temp_res;