12:08 p.m.
Enable basic overflow in optimization checks (portability related) and
missed loop optimizations. The latter (-Wunsafe-loop-optimizations)
does not work well with GCC v7.5 so simply skip it there.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)canonical.com>
---
accflags.m4 | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/accflags.m4 b/accflags.m4
index 57cc48beecc2..0030ac339c86 100644
--- a/accflags.m4
+++ b/accflags.m4
@@ -24,6 +24,7 @@ AC_DEFUN([NEARD_COMPILER_FLAGS], [
AX_CHECK_COMPILE_FLAG([-Wjump-misses-init], [CFLAGS="$CFLAGS
-Wjump-misses-init"])
AX_CHECK_COMPILE_FLAG([-Wpointer-arith], [CFLAGS="$CFLAGS -Wpointer-arith"])
AX_CHECK_COMPILE_FLAG([-Wshadow], [CFLAGS="$CFLAGS -Wshadow"])
+ AX_CHECK_COMPILE_FLAG([-Wstrict-overflow=2], [CFLAGS="$CFLAGS
-Wstrict-overflow=2"])
# GCC v5.0
AX_CHECK_COMPILE_FLAG([-Wformat-signedness], [CFLAGS="$CFLAGS
-Wformat-signedness"])
@@ -36,10 +37,16 @@ AC_DEFUN([NEARD_COMPILER_FLAGS], [
AX_CHECK_COMPILE_FLAG([-Walloc-zero], [CFLAGS="$CFLAGS -Walloc-zero"])
# GCC v8.0
AX_CHECK_COMPILE_FLAG([-Wstringop-truncation], [CFLAGS="$CFLAGS
-Wstringop-truncation"])
+
+ # GCC v7.5 from Ubuntu Bionic incorrectly assumes several loops can overflow, so
enable
+ # -Wunsafe-loop-optimizations only on newer GCC.
+ CC_VERSION=`$CC --version | head -n 1 | sed -e 's/.*\
\(@<:@0-9@:>@\+\.@<:@0-9@:>@\+\.@<:@0-9@:>@\+\)\(-@<:@0-9@:>@\+\)\?$/\1/'`
+ AX_COMPARE_VERSION([$CC_VERSION],[ge],[8.0.0],
+ [AX_CHECK_COMPILE_FLAG([-Wunsafe-loop-optimizations], [CFLAGS="$CFLAGS
-Wunsafe-loop-optimizations"])], [])
fi
if (test "$USE_MAINTAINER_MODE" = "pedantic"); then
- AX_CHECK_COMPILE_FLAG([-Wstrict-overflow=3], [CFLAGS="$CFLAGS
-Wstrict-overflow=3"])
AX_CHECK_COMPILE_FLAG([-Wcast-qual], [CFLAGS="$CFLAGS -Wcast-qual"])
- AX_CHECK_COMPILE_FLAG([-Wunsafe-loop-optimizations], [CFLAGS="$CFLAGS
-Wunsafe-loop-optimizations"])
+ # Instead of -Wstrict-overflow=2
+ AX_CHECK_COMPILE_FLAG([-Wstrict-overflow=3], [CFLAGS="$CFLAGS
-Wstrict-overflow=3"])
fi
])
--
2.27.0