configure: Disable -Werror by default if sanitizers are enabled

Commit Message

Akihiko Odaki March 27, 2024, 8:35 a.m. UTC

With GCC 13.2.1 I got the following warning when sanitizers are enabled:

../hw/net/rtl8139.c: In function 'rtl8139_io_writeb':
../hw/net/rtl8139.c:2273:17: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
 2273 |                 memcpy(data_to_checksum, saved_ip_header + 12, 8);

The bug is reported upstream and you can find details at:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114494

The GCC documentation states it is not recommended to combine -Werror
and sanitizers so disable -Werror by default if sanitizers are enabled.

Signed-off-by: Akihiko Odaki <[e-mail]>
---
 configure | 12 ++++++++++++
 1 file changed, 12 insertions(+)


---
base-commit: ba49d760eb04630e7b15f423ebecf6c871b8f77b
change-id: 20240327-werror-5d2e974c3d7d

Best regards,

Patch

diff --git a/configure b/configure
index 3cd736b139f3..3407f9971db1 100755
--- a/configure
+++ b/configure
@@ -262,6 +262,7 @@  unset target_list_exclude
 # The following Meson options are handled manually (still they
 # are included in the automatically generated help message)
 # because they automatically enable/disable other options
+sanitizers=no
 tcg="auto"
 cfi="false"
 
@@ -713,6 +714,10 @@  for opt do
       meson_option_add -Doptimization=0
       default_cflags='-O0 -g'
   ;;
+  --disable-sanitizers) sanitizers=no
+  ;;
+  --enable-sanitizers) sanitizers=yes
+  ;;
   --disable-tcg) tcg="disabled"
   ;;
   --enable-tcg) tcg="enabled"
@@ -1706,9 +1711,15 @@  if test "$skip_meson" = no; then
   echo "cpp_link_args = [$(meson_quote $CXXFLAGS $LDFLAGS $EXTRA_CXXFLAGS $EXTRA_LDFLAGS)]" >> $cross
 
   # Only enable by default for git builds and on select OSes
+  # Also don't enable if sanitizers are enabled. The GCC documentation says:
+  # > Note that sanitizers tend to increase the rate of false positive warnings,
+  # > most notably those around -Wmaybe-uninitialized. We recommend against
+  # > combining -Werror and [the use of] sanitizers.
+  # https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/Instrumentation-Options.html
   echo "# environment defaults, can still be overridden on " >> $cross
   echo "# the command line" >> $cross
   if test -e "$source_path/.git" && \
+      test "$sanitizers" == no && \
       { test "$host_os" = linux || test "$host_os" = "windows"; }; then
       echo 'werror = true' >> $cross
   fi
@@ -1789,6 +1800,7 @@  if test "$skip_meson" = no; then
   test -n "${LIB_FUZZING_ENGINE+xxx}" && meson_option_add "-Dfuzzing_engine=$LIB_FUZZING_ENGINE"
   test "$plugins" = yes && meson_option_add "-Dplugins=true"
   test "$tcg" != enabled && meson_option_add "-Dtcg=$tcg"
+  test "$sanitizers" = yes && meson_option_add -Dsanitizers=true
   run_meson() {
     NINJA=$ninja $meson setup "$@" "$PWD" "$source_path"
   }