From: Sam Ravnborg Date: Sat, 30 Apr 2005 23:51:42 +0000 (-0700) Subject: [PATCH] kbuild: Set NOSTDINC_FLAGS late to speed up compile (a little) X-Git-Tag: firefly_0821_release~42725^2~250 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e8e6993178344eb348f60f05b16d9dc30db3b9cf;p=firefly-linux-kernel-4.4.55.git [PATCH] kbuild: Set NOSTDINC_FLAGS late to speed up compile (a little) Move definition of NOSTDINC_FLAGS below inclusion of arch Makefile, so any arch specific settings to $(CC) takes effect before looking up the compiler include directory. The previous solution that replaced ':=' with '=' caused gcc to be invoked one additional time for each directory visited. This decreases kernel compile time with 0.1 second (3.6 -> 3.5 seconds) when running make on a fully built kernel Signed-off-by: Sam Ravnborg Signed-off-by: Linus Torvalds --- diff --git a/Makefile b/Makefile index 8da3a306d0c0..48990899db0d 100644 --- a/Makefile +++ b/Makefile @@ -332,9 +332,7 @@ KALLSYMS = scripts/kallsyms PERL = perl CHECK = sparse -NOSTDINC_FLAGS = -nostdinc -isystem $(shell $(CC) -print-file-name=include) CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -CHECKFLAGS += $(NOSTDINC_FLAGS) MODFLAGS = -DMODULE CFLAGS_MODULE = $(MODFLAGS) AFLAGS_MODULE = $(MODFLAGS) @@ -531,6 +529,10 @@ endif include $(srctree)/arch/$(ARCH)/Makefile +# 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) + # warn about C99 declaration after statement CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)