perf build: Do not use -Wshadow on gcc < 4.8

As it is too strict, see https://lkml.org/lkml/2006/11/28/253 and https://gcc.gnu.org/gcc-4.8/changes.html, that takes into account Linus's comments (search for Wshadow) for the reasoning about -Wshadow not being interesting before gcc 4.8. Acked-by: Andrii Nakryiko <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
LoveHeat · Jul 23, 2019 · 39e7317 · 39e7317
1 parent d95daf5
commit 39e7317
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
@@ -32,7 +32,6 @@ EXTRA_WARNINGS += -Wno-system-headers
 EXTRA_WARNINGS += -Wold-style-definition
 EXTRA_WARNINGS += -Wpacked
 EXTRA_WARNINGS += -Wredundant-decls
-EXTRA_WARNINGS += -Wshadow
 EXTRA_WARNINGS += -Wstrict-prototypes
 EXTRA_WARNINGS += -Wswitch-default
 EXTRA_WARNINGS += -Wswitch-enum
@@ -69,8 +68,16 @@ endif
 # will do for now and keep the above -Wstrict-aliasing=3 in place
 # in newer systems.
 # Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h
+#
+# See https://lkml.org/lkml/2006/11/28/253 and https://gcc.gnu.org/gcc-4.8/changes.html,
+# that takes into account Linus's comments (search for Wshadow) for the reasoning about
+# -Wshadow not being interesting before gcc 4.8.
+
 ifneq ($(filter 3.%,$(MAKE_VERSION)),)  # make-3
 EXTRA_WARNINGS += -fno-strict-aliasing
+EXTRA_WARNINGS += -Wno-shadow
+else
+EXTRA_WARNINGS += -Wshadow
 endif
 
 ifneq ($(findstring $(MAKEFLAGS), w),w)