Wrap malloc and friends and report out of memory as GIT_ENOMEM

We now forbid direct use of malloc, strdup or calloc within the
library and instead use wrapper functions git__malloc, etc. to
invoke the underlying library malloc and set git_errno to a no
memory error code if the allocation fails.

In the future once we have pack objects in memory we are likely
to enhance these routines with garbage collection logic to purge
cached pack data when allocations fail.  Because the size of the
function will grow somewhat large, we don't want to mark them for
inline as gcc tends to aggressively inline, creating larger than
expected executables.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/src/odb.c b/src/odb.c
index e96aa1e25..e074873b8 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -279,7 +279,7 @@ static void *inflate_tail(z_stream *s, void *hb, size_t used, obj_hdr *hdr)
 	 * initial sequence of inflated data from the tail of the
 	 * head buffer, if any.
 	 */
-	if ((buf = malloc(hdr->size + 1)) == NULL)
+	if ((buf = git__malloc(hdr->size + 1)) == NULL)
 		return NULL;
 	tail = s->total_out - used;
 	if (used > 0 && tail > 0) {
@@ -352,7 +352,10 @@ static int inflate_packlike_loose_disk_obj(git_obj *out, gitfo_buf *obj)
 	/*
 	 * allocate a buffer and inflate the data into it
 	 */
-	buf = malloc(hdr.size+1);
+	buf = git__malloc(hdr.size + 1);
+	if (!buf)
+		return GIT_ERROR;
+
 	in  = ((unsigned char *)obj->data) + used;
 	len = obj->len - used;
 	if (inflate_buffer(in, len, buf, hdr.size)) {
@@ -414,7 +417,7 @@ static int open_alternates(git_odb *db)
 {
 	unsigned n = 0;
 
-	db->alternates = malloc(sizeof(*db->alternates) * (n + 1));
+	db->alternates = git__malloc(sizeof(*db->alternates) * (n + 1));
 	if (!db->alternates)
 		return GIT_ERROR;
 
@@ -424,11 +427,11 @@ static int open_alternates(git_odb *db)
 
 int git_odb_open(git_odb **out, const char *objects_dir)
 {
-	git_odb *db = malloc(sizeof(*db));
+	git_odb *db = git__malloc(sizeof(*db));
 	if (!db)
 		return GIT_ERROR;
 
-	db->objects_dir = strdup(objects_dir);
+	db->objects_dir = git__strdup(objects_dir);
 	if (!db->objects_dir) {
 		free(db);
 		return GIT_ERROR;