tools/perf/build: Remove the volatile-register-var feature check
Namhyung Kim noticed that the volatile-register-var feature check
is superfluous:
> The gcc manpage says this warning is enabled by -Wall, and we add -Wall
> to CFLAGS before doing feature checks. So all gcc versions that support
> -Wvolatile-register-var enables it by default without this check and
> older gcc versions will always fail the feature check.
Remove it - this will further speed up feature checks.
Reported-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index d207922..c516d6ba 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -132,8 +132,7 @@
libunwind \
on-exit \
stackprotector \
- stackprotector-all \
- volatile-register-var
+ stackprotector-all
#
# So here we detect whether test-all was rebuilt, to be able
@@ -203,10 +202,6 @@
CFLAGS += -Wstack-protector
endif
-ifeq ($(feature-volatile-register-var), 1)
- CFLAGS += -Wvolatile-register-var
-endif
-
ifeq ($(DEBUG),0)
ifeq ($(feature-fortify-source), 1)
CFLAGS += -D_FORTIFY_SOURCE=2