kbuild: remove GCC_VERSION

This was causing some ordering problems.  Remove the up-front evaluation
and just revaluate the compiler version each time we need it.

(The up-front evaluation was problematic because some architectures modify
the value of $(CC)).

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Documentation/kbuild/makefiles.txt

@@ -1033,9 +1033,9 @@ When kbuild executes the following steps are followed (roughly):
 
 	Example:
 		#arch/i386/Makefile
-		GCC_VERSION := $(call cc-version)
 		cflags-y += $(shell \
-		if [ $(GCC_VERSION) -ge 0300 ] ; then echo "-mregparm=3"; fi ;)
+		if [ $(call cc-version) -ge 0300 ] ; then \
+			echo "-mregparm=3"; fi ;)
 
 	In the above example -mregparm=3 is only used for gcc version greater
 	than or equal to gcc 3.0.

arch/i386/Makefile

@@ -39,8 +39,8 @@ include $(srctree)/arch/i386/Makefile.cpu
 
 # -mregparm=3 works ok on gcc-3.0 and later
 #
-GCC_VERSION			:= $(call cc-version)
-cflags-$(CONFIG_REGPARM) 	+= $(shell if [ $(GCC_VERSION) -ge 0300 ] ; then echo "-mregparm=3"; fi ;)
+cflags-$(CONFIG_REGPARM) += $(shell if [ $(call cc-version) -ge 0300 ] ; then \
+                            echo "-mregparm=3"; fi ;)
 
 # Disable unit-at-a-time mode, it makes gcc use a lot more stack
 # due to the lack of sharing of stacklots.

arch/ia64/Makefile

@@ -25,7 +25,6 @@ cflags-y	:= -pipe $(EXTRA) -ffixed-r13 -mfixed-range=f12-f15,f32-f127 \
 		   -falign-functions=32 -frename-registers -fno-optimize-sibling-calls
 CFLAGS_KERNEL	:= -mconstant-gp
 
-GCC_VERSION     := $(call cc-version)
 GAS_STATUS	= $(shell $(srctree)/arch/ia64/scripts/check-gas "$(CC)" "$(OBJDUMP)")
 CPPFLAGS += $(shell $(srctree)/arch/ia64/scripts/toolchain-flags "$(CC)" "$(OBJDUMP)" "$(READELF)")
 
@@ -37,11 +36,7 @@ $(error Sorry, you need a newer version of the assember, one that is built from
 		ftp://ftp.hpl.hp.com/pub/linux-ia64/gas-030124.tar.gz)
 endif
 
-ifneq ($(shell if [ $(GCC_VERSION) -lt 0300 ] ; then echo "bad"; fi ;),)
-$(error Sorry, your compiler is too old.  GCC v2.96 is known to generate bad code.)
-endif
-
-ifeq ($(GCC_VERSION),0304)
+ifeq ($(call cc-version),0304)
 	cflags-$(CONFIG_ITANIUM)	+= -mtune=merced
 	cflags-$(CONFIG_MCKINLEY)	+= -mtune=mckinley
 endif

arch/powerpc/Makefile

@@ -76,8 +76,7 @@ LINUXINCLUDE    += $(LINUXINCLUDE-y)
 CHECKFLAGS	+= -m$(SZ) -D__powerpc__ -D__powerpc$(SZ)__
 
 ifeq ($(CONFIG_PPC64),y)
-GCC_VERSION     := $(call cc-version)
-GCC_BROKEN_VEC	:= $(shell if [ $(GCC_VERSION) -lt 0400 ] ; then echo "y"; fi)
+GCC_BROKEN_VEC	:= $(shell if [ $(call cc-version) -lt 0400 ] ; then echo "y"; fi)
 
 ifeq ($(CONFIG_POWER4_ONLY),y)
 ifeq ($(CONFIG_ALTIVEC),y)
@@ -189,10 +188,9 @@ TOUT	:= .tmp_gas_check
 # Ensure this is binutils 2.12.1 (or 2.12.90.0.7) or later for altivec
 # instructions.
 # gcc-3.4 and binutils-2.14 are a fatal combination.
-GCC_VERSION	:= $(call cc-version)
 
 checkbin:
-	@if test "$(GCC_VERSION)" = "0304" ; then \
+	@if test "$(call cc-version)" = "0304" ; then \
 		if ! /bin/echo mftb 5 | $(AS) -v -mppc -many -o $(TOUT) >/dev/null 2>&1 ; then \
 			echo -n '*** ${VERSION}.${PATCHLEVEL} kernels no longer build '; \
 			echo 'correctly with gcc-3.4 and your version of binutils.'; \

arch/ppc/Makefile

@@ -128,10 +128,9 @@ TOUT	:= .tmp_gas_check
 # Ensure this is binutils 2.12.1 (or 2.12.90.0.7) or later for altivec
 # instructions.
 # gcc-3.4 and binutils-2.14 are a fatal combination.
-GCC_VERSION	:= $(call cc-version)
 
 checkbin:
-	@if test "$(GCC_VERSION)" = "0304" ; then \
+	@if test "$(call cc-version)" = "0304" ; then \
 		if ! /bin/echo mftb 5 | $(AS) -v -mppc -many -o $(TOUT) >/dev/null 2>&1 ; then \
 			echo -n '*** ${VERSION}.${PATCHLEVEL} kernels no longer build '; \
 			echo 'correctly with gcc-3.4 and your version of binutils.'; \