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authorJunio C Hamano <gitster@pobox.com>2016-06-27 09:56:48 -0700
committerJunio C Hamano <gitster@pobox.com>2016-06-27 09:56:48 -0700
commit269085e16e26d5096b5458ae89d63eb27de26eb7 (patch)
treea12a680fe4ae293889a74ef65f020d734192978b
parent2380db5b28aff110cd8f6ef2bb65dd5ab49303b2 (diff)
parentb8ba412bf7c38ac86dbaebdf939b0039bacf434c (diff)
downloadgit-269085e16e26d5096b5458ae89d63eb27de26eb7.tar.gz
Merge branch 'jk/avoid-unbounded-alloca'
* jk/avoid-unbounded-alloca: tree-diff: avoid alloca for large allocations
-rw-r--r--tree-diff.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/tree-diff.c b/tree-diff.c
index edb4de9b72..e164e532b2 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -14,6 +14,16 @@
*/
#define S_IFXMIN_NEQ S_DIFFTREE_IFXMIN_NEQ
+#define FAST_ARRAY_ALLOC(x, nr) do { \
+ if ((nr) <= 2) \
+ (x) = xalloca((nr) * sizeof(*(x))); \
+ else \
+ ALLOC_ARRAY((x), nr); \
+} while(0)
+#define FAST_ARRAY_FREE(x, nr) do { \
+ if ((nr) > 2) \
+ free((x)); \
+} while(0)
static struct combine_diff_path *ll_diff_tree_paths(
struct combine_diff_path *p, const unsigned char *sha1,
@@ -265,7 +275,7 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
if (recurse) {
const unsigned char **parents_sha1;
- parents_sha1 = xalloca(nparent * sizeof(parents_sha1[0]));
+ FAST_ARRAY_ALLOC(parents_sha1, nparent);
for (i = 0; i < nparent; ++i) {
/* same rule as in emitthis */
int tpi_valid = tp && !(tp[i].entry.mode & S_IFXMIN_NEQ);
@@ -277,7 +287,7 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
strbuf_add(base, path, pathlen);
strbuf_addch(base, '/');
p = ll_diff_tree_paths(p, sha1, parents_sha1, nparent, base, opt);
- xalloca_free(parents_sha1);
+ FAST_ARRAY_FREE(parents_sha1, nparent);
}
strbuf_setlen(base, old_baselen);
@@ -402,8 +412,8 @@ static struct combine_diff_path *ll_diff_tree_paths(
void *ttree, **tptree;
int i;
- tp = xalloca(nparent * sizeof(tp[0]));
- tptree = xalloca(nparent * sizeof(tptree[0]));
+ FAST_ARRAY_ALLOC(tp, nparent);
+ FAST_ARRAY_ALLOC(tptree, nparent);
/*
* load parents first, as they are probably already cached.
@@ -531,8 +541,8 @@ static struct combine_diff_path *ll_diff_tree_paths(
free(ttree);
for (i = nparent-1; i >= 0; i--)
free(tptree[i]);
- xalloca_free(tptree);
- xalloca_free(tp);
+ FAST_ARRAY_FREE(tptree, nparent);
+ FAST_ARRAY_FREE(tp, nparent);
return p;
}