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Disable -Wrestrict for two nptl/tst-attr3.c tests [committed]
- From: Joseph Myers <joseph at codesourcery dot com>
- To: <libc-alpha at sourceware dot org>
- Date: Mon, 18 Dec 2017 22:56:08 +0000
- Subject: Disable -Wrestrict for two nptl/tst-attr3.c tests [committed]
- Authentication-results: sourceware.org; auth=none
nptl/tst-attr3 fails to build with GCC mainline because of
(deliberate) aliasing between the second (attributes) and fourth
(argument to thread start routine) arguments to pthread_create.
Although both those arguments are restrict-qualified in POSIX,
pthread_create does not actually dereference its fourth argument; it's
an opaque pointer passed to the thread start routine. Thus, the
aliasing is actually valid in this case, and it's deliberate in the
test. So this patch makes the test disable -Wrestrict for the two
pthread_create calls in question. (-Wrestrict was added in GCC 7,
hence the __GNUC_PREREQ conditions, but the particular warning in
question is new in GCC 8.)
Tested compilation with build-many-glibcs.py for aarch64-linux-gnu.
Committed.
2017-12-18 Joseph Myers <joseph@codesourcery.com>
* nptl/tst-attr3.c: Include <libc-diag.h>.
(do_test) [__GNUC_PREREQ (7, 0)]: Ignore -Wrestrict for two tests.
diff --git a/nptl/tst-attr3.c b/nptl/tst-attr3.c
index bc23386..420a7db 100644
--- a/nptl/tst-attr3.c
+++ b/nptl/tst-attr3.c
@@ -26,6 +26,7 @@
#include <unistd.h>
#include <stackinfo.h>
+#include <libc-diag.h>
static void *
tf (void *arg)
@@ -362,7 +363,16 @@ do_test (void)
result = 1;
}
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (7, 0)
+ /* GCC 8 warns about aliasing of the restrict-qualified arguments
+ passed &a. Since pthread_create does not dereference its fourth
+ argument, this aliasing, which is deliberate in this test, cannot
+ in fact cause problems. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wrestrict");
+#endif
err = pthread_create (&th, &a, tf, &a);
+ DIAG_POP_NEEDS_COMMENT;
if (err)
{
error (0, err, "pthread_create #2 failed");
@@ -388,7 +398,16 @@ do_test (void)
result = 1;
}
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (7, 0)
+ /* GCC 8 warns about aliasing of the restrict-qualified arguments
+ passed &a. Since pthread_create does not dereference its fourth
+ argument, this aliasing, which is deliberate in this test, cannot
+ in fact cause problems. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wrestrict");
+#endif
err = pthread_create (&th, &a, tf, &a);
+ DIAG_POP_NEEDS_COMMENT;
if (err)
{
error (0, err, "pthread_create #3 failed");
--
Joseph S. Myers
joseph@codesourcery.com