From 429312d686f0c0b2c953639d298d942dcea531b9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Mon, 19 Jul 2021 19:16:59 +0100 Subject: [PATCH] meson: disable bogus warnings from sanitizers on Fedora MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When building with sanitizers on Fedora we get a wierd error message In file included from /usr/include/string.h:519, from ../src/internal.h:28, from ../src/util/virsocket.h:21, from ../src/util/virsocketaddr.h:21, from ../src/util/virnetdevip.h:21, from ../src/util/virnetdevip.c:21: In function ‘memcpy’, inlined from ‘virNetDevGetifaddrsAddress’ at ../src/util/virnetdevip.c:702:13, inlined from ‘virNetDevIPAddrGet’ at ../src/util/virnetdevip.c:754:16: /usr/include/bits/string_fortified.h:29:10: error: ‘__builtin_memcpy’ offset [2, 27] from the object at ‘addr’ is out of the bounds of referenced subobject ‘ss_family’ with type ‘short unsigned int’ at offset 0 [-Werror=array-bounds] 29 | return __builtin___memcpy_chk (__dest, __src, __len, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 30 | __glibc_objsize0 (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/bits/socket.h:175, from /usr/include/sys/socket.h:33, from ../src/util/virsocket.h:66, from ../src/util/virsocketaddr.h:21, from ../src/util/virnetdevip.h:21, from ../src/util/virnetdevip.c:21: ../src/util/virnetdevip.c: In function ‘virNetDevIPAddrGet’: /usr/include/bits/socket.h:193:5: note: subobject ‘ss_family’ declared here 193 | __SOCKADDR_COMMON (ss_); /* Address family, etc. */ | ^~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors The code is correct, and this only happens when building at -O2. The docs for -Warray-bounds say that a value of "2" is known to be liable to generate false positives. Rather than downgrade the check everywhere, we do it selectively for sanitizers. Reviewed-by: Tim Wiederhake Signed-off-by: Daniel P. Berrangé --- meson.build | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/meson.build b/meson.build index ca4291e37a..d4c142eebb 100644 --- a/meson.build +++ b/meson.build @@ -227,6 +227,11 @@ alloc_max = run_command( # sanitizer instrumentation may enlarge stack frames stack_frame_size = get_option('b_sanitize') == 'none' ? 4096 : 8192 +# array_bounds=2 check triggers false positive on some GCC +# versions when using sanitizers. Seen on Fedora 34 with +# GCC 11.1.1 +array_bounds = get_option('b_sanitize') == 'none' ? 2 : 1 + cc_flags += [ '-fasynchronous-unwind-tables', '-fexceptions', @@ -238,7 +243,7 @@ cc_flags += [ '-Waggressive-loop-optimizations', '-Walloc-size-larger-than=@0@'.format(alloc_max.stdout().strip()), '-Walloca', - '-Warray-bounds=2', + '-Warray-bounds=@0@'.format(array_bounds), '-Wattribute-alias=2', '-Wattribute-warning', '-Wattributes',