[Pixman] [PATCH] Add destructor function to free pixman_implementation_t structs on exit

[Siarhei Siamashka]

This fixes a few small memory leaks detected by valgrind. This memory
was allocated once on pixman library load and never freed (but still
was reachable). The fix only helps if the compiler has support for
__attribute__((constructor)) and __attribute__((destructor))
function attributes.

Reported-by: Emil Velikov <emil.l.velikov at gmail.com>
Signed-off-by: Siarhei Siamashka <siarhei.siamashka at gmail.com>
---
 configure.ac    |  1 +
 pixman/pixman.c | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/configure.ac b/configure.ac
index e833e45..a592cba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1047,6 +1047,7 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([[
  */
 static int x = 1;
 static void __attribute__((constructor)) constructor_function () { x = 0; }
+static void __attribute__((destructor)) destructor_function () { x = 0; }
 int main (void) { return x; }
 #else
 #error not gcc or gcc version is older than 2.7
diff --git a/pixman/pixman.c b/pixman/pixman.c
index f932eac..0bcc832 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -38,6 +38,18 @@ pixman_constructor (void)
 {
     global_implementation = _pixman_choose_implementation ();
 }
+
+static void __attribute__((destructor))
+pixman_destructor (void)
+{
+    pixman_implementation_t *imp = global_implementation;
+    while (imp)
+    {
+	pixman_implementation_t *fallback = imp->fallback;
+	free (imp);
+	imp = fallback;
+    }
+}
 #endif
 
 typedef struct operator_info_t operator_info_t;
-- 
2.7.3