[PATCH][next] init: Kconfig: Disable -Wstringop-overflow for GCC-11

From: Gustavo A. R. Silva
Date: Thu Nov 30 2023 - 15:52:18 EST


-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW.

The compiler option related to string operation overflow is now managed
under configuration CC_STRINGOP_OVERFLOW. This option is enabled by
default for all other versions of GCC that support it.

Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
Makefile | 4 +++-
init/Kconfig | 12 ++++++++++++
2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 2cfd71ae3a86..8adc611fb611 100644
--- a/Makefile
+++ b/Makefile
@@ -982,7 +982,9 @@ NOSTDINC_FLAGS += -nostdinc
# perform bounds checking.
KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)

-KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow)
+#Currently, disable -Wstringop-overflow for GCC 11, globally.
+KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
+KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)

# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += -fno-strict-overflow
diff --git a/init/Kconfig b/init/Kconfig
index 9ffb103fc927..aaaa99a5d2a9 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -876,6 +876,18 @@ config CC_NO_ARRAY_BOUNDS
bool
default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC11_NO_ARRAY_BOUNDS

+# Currently, disable -Wstringop-overflow for GCC 11, globally.
+config GCC11_NO_STRINGOP_OVERFLOW
+ def_bool y
+
+config CC_NO_STRINGOP_OVERFLOW
+ bool
+ default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC_VERSION < 120000 && GCC11_NO_STRINGOP_OVERFLOW
+
+config CC_STRINGOP_OVERFLOW
+ bool
+ default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW
+
#
# For architectures that know their GCC __int128 support is sound
#
--
2.34.1