Commit 61754c18 authored by Michal Marek's avatar Michal Marek Committed by Vineet Gupta
Browse files

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: default avatarVineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: default avatarMichal Marek <mmarek@suse.com>
parent b607eddd

Documentation/kbuild/makefiles.txt

+8 −0
Original line number Diff line number Diff line
@@ -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

Makefile

+5 −4
Original line number Diff line number Diff line
@@ -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)%,%,\

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