[libgsystem] localalloc: Add gs_fd_close cleanup

[Colin Walters <walters src gnome org>]

commit ad3a28c5f2520d0688730aa83eaee815fb9a5762
Author: Colin Walters <walters verbum org>
Date:   Wed Dec 17 22:28:58 2014 -0500

    localalloc: Add gs_fd_close cleanup
    
    Now that we're encouraging use of openat(), fds are a lot more
    prevalent.

 src/gsystem-local-alloc.h |   19 +++++++++++++++++++
 tests/localalloc.c        |    2 ++
 2 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/src/gsystem-local-alloc.h b/src/gsystem-local-alloc.h
index 71f444b..51b6251 100644
--- a/src/gsystem-local-alloc.h
+++ b/src/gsystem-local-alloc.h
@@ -184,6 +184,25 @@ GS_DEFINE_CLEANUP_FUNCTION0(GError*, gs_local_free_error, g_error_free)
 #define gs_unref_keyfile __attribute__ ((cleanup(gs_local_keyfile_unref)))
 GS_DEFINE_CLEANUP_FUNCTION0(GKeyFile*, gs_local_keyfile_unref, g_key_file_unref)
 
+static inline void
+gs_cleanup_close_fdp (int *fdp)
+{
+  int fd;
+
+  g_assert (fdp);
+  
+  fd = *fdp;
+  if (fd != -1)
+    (void) close (fd);
+}
+
+/**
+ * gs_fd_close:
+ *
+ * Call close() on a variable location when it goes out of scope.
+ */
+#define gs_fd_close __attribute__((cleanup(gs_cleanup_close_fdp)))
+
 G_END_DECLS
 
 #endif
diff --git a/tests/localalloc.c b/tests/localalloc.c
index 46024c3..087261a 100644
--- a/tests/localalloc.c
+++ b/tests/localalloc.c
@@ -25,6 +25,8 @@ test_localalloc (void)
   gs_strfreev char **strv = g_get_environ ();
   gs_free_error GError *err = g_error_new (G_IO_ERROR, G_IO_ERROR_FAILED, "oops %s", "darn!");
   gs_unref_keyfile GKeyFile *keyfile = g_key_file_new ();
+  gs_fd_close int fd = open ("/dev/null", O_RDONLY);
+  gs_fd_close int fd2 = -1;
 }
 
 int