From 61754c18752ffb78145671e94f053fb202fff041 Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Wed, 1 Jul 2015 17:19:30 +0200 Subject: [PATCH] kbuild: Allow arch Makefiles to override {cpp,ld,c}flags Since commit a1c48bb1 (Makefile: Fix unrecognized cross-compiler command line options), the arch Makefile is included earlier by the main Makefile, preventing the arc architecture to set its -O3 compiler option. Since there might be more use cases for an arch Makefile to fine-tune the options, add support for ARCH_CPPFLAGS, ARCH_AFLAGS and ARCH_CFLAGS variables that are appended to the respective kbuild variables. The user still has the final say via the KCPPFLAGS, KAFLAGS and KCFLAGS variables. Reported-by: Vineet Gupta Cc: stable@vger.kernel.org # 3.16+ Signed-off-by: Michal Marek --- Documentation/kbuild/makefiles.txt | 8 ++++++++ Makefile | 9 +++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index e63b446d973c..13f888a02a3d 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -952,6 +952,14 @@ When kbuild executes, the following steps are followed (roughly): $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic mode) if this option is supported by $(AR). + ARCH_CPPFLAGS, ARCH_AFLAGS, ARCH_CFLAGS Overrides the kbuild defaults + + These variables are appended to the KBUILD_CPPFLAGS, + KBUILD_AFLAGS, and KBUILD_CFLAGS, respectively, after the + top-level Makefile has set any other flags. This provides a + means for an architecture to override the defaults. + + --- 6.2 Add prerequisites to archheaders: The archheaders: rule is used to generate header files that diff --git a/Makefile b/Makefile index 13270c0a9336..8c31fbc90589 100644 --- a/Makefile +++ b/Makefile @@ -780,10 +780,11 @@ endif include scripts/Makefile.kasan include scripts/Makefile.extrawarn -# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments -KBUILD_CPPFLAGS += $(KCPPFLAGS) -KBUILD_AFLAGS += $(KAFLAGS) -KBUILD_CFLAGS += $(KCFLAGS) +# Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the +# last assignments +KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS) +KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS) +KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS) # Use --build-id when available. LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\ -- 2.25.1