Arnd Bergmann reported:
"When ftrace is enabled and we build with gcc-4.7 or older, we
get a warning for each file on architectures that select
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION:
warning: -ffunction-sections disabled; it makes profiling impossible [enabled by default]
"
Since commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to
cc-option to support clang"), warnings are treated as errors in
cc-option checks. CC_FLAGS_FTRACE is blindly added to KBUILD_CFLAGS,
so $(call cc-option,-ffunction-sections,) should be moved below it
in order to detect the conflict between the two options.
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---
Makefile | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/Makefile b/Makefile
index efa267a..753e450 100644
--- a/Makefile
+++ b/Makefile
@@ -632,11 +632,6 @@ include arch/$(SRCARCH)/Makefile
KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
-ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
-KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
-KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
-endif
-
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,)
else
@@ -773,6 +768,11 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
endif
+ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
+KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
+KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
+endif
+
# arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
CHECKFLAGS += $(NOSTDINC_FLAGS)
--
2.7.4
--
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