From: Pierrick Bouvier <pierrick.bouvier@linaro.org>

When building with gcc-12 -fsanitize=thread, gcc reports some
constructions not supported with tsan.
Found on debian stable.

qemu/include/qemu/atomic.h:36:52: error: ‘atomic_thread_fence’ is not supported with ‘-fsanitize=thread’ [-Werror=tsan]
   36 | #define smp_mb()                     ({ barrier(); __atomic_thread_fence(__ATOMIC_SEQ_CST); })
      |                                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20240910174013.1433331-2-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 meson.build | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index d26690ce20..bdd67a2d6d 100644
--- a/meson.build
+++ b/meson.build
@@ -538,7 +538,15 @@ if get_option('tsan')
                          prefix: '#include <sanitizer/tsan_interface.h>')
     error('Cannot enable TSAN due to missing fiber annotation interface')
   endif
-  qemu_cflags = ['-fsanitize=thread'] + qemu_cflags
+  tsan_warn_suppress = []
+  # gcc (>=11) will report constructions not supported by tsan:
+  # "error: ‘atomic_thread_fence’ is not supported with ‘-fsanitize=thread’"
+  # https://gcc.gnu.org/gcc-11/changes.html
+  # However, clang does not support this warning and this triggers an error.
+  if cc.has_argument('-Wno-tsan')
+    tsan_warn_suppress = ['-Wno-tsan']
+  endif
+  qemu_cflags = ['-fsanitize=thread'] + tsan_warn_suppress + qemu_cflags
   qemu_ldflags = ['-fsanitize=thread'] + qemu_ldflags
 endif
 
-- 
2.39.5