Merge branch 'rs/qsort-s'

A few codepaths had to rely on a global variable when sorting
elements of an array because sort(3) API does not allow extra data
to be passed to the comparison function.  Use qsort_s() when
natively available, and a fallback implementation of it when not,
to eliminate the need, which is a prerequisite for making the
codepath reentrant.

* rs/qsort-s:
  ref-filter: use QSORT_S in ref_array_sort()
  string-list: use QSORT_S in string_list_sort()
  perf: add basic sort performance test
  add QSORT_S
  compat: add qsort_s()

1 files changed, 11 insertions, 0 deletions

diff --git a/git-compat-util.h b/git-compat-util.h
index 87237b092b..f46d40e4a4 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -988,6 +988,17 @@ static inline void sane_qsort(void *base, size_t nmemb, size_t size,
 		qsort(base, nmemb, size, compar);
 }
 
+#ifndef HAVE_ISO_QSORT_S
+int git_qsort_s(void *base, size_t nmemb, size_t size,
+		int (*compar)(const void *, const void *, void *), void *ctx);
+#define qsort_s git_qsort_s
+#endif
+
+#define QSORT_S(base, n, compar, ctx) do {			\
+	if (qsort_s((base), (n), sizeof(*(base)), compar, ctx))	\
+		die("BUG: qsort_s() failed");			\
+} while (0)
+
 #ifndef REG_STARTEND
 #error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
 #endif