From 5631d9c429857194bd55d7bcd8fa5bdd1a9899a3 Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Wed, 19 Aug 2015 17:36:41 +0200 Subject: [PATCH] kbuild: Fix clang detection We cannot detect clang before including the arch Makefile, because that can set the default cross compiler. We also cannot detect clang after including the arch Makefile, because powerpc wants to know about clang. Solve this by using an deferred variable. This costs us a few shell invocations, but this is only a constant number. Reported-by: Behan Webster Reported-by: Anton Blanchard Signed-off-by: Michal Marek --- Makefile | 9 +-------- arch/powerpc/Makefile | 8 ++++---- scripts/Kbuild.include | 4 ++++ scripts/Makefile.extrawarn | 2 +- 4 files changed, 10 insertions(+), 13 deletions(-) diff --git a/Makefile b/Makefile index 13270c0a9336..5ccbb58553ab 100644 --- a/Makefile +++ b/Makefile @@ -661,14 +661,7 @@ endif endif KBUILD_CFLAGS += $(stackp-flag) -ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1) -COMPILER := clang -else -COMPILER := gcc -endif -export COMPILER - -ifeq ($(COMPILER),clang) +ifeq ($(cc-name),clang) KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,) KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,) KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 05f464eb6952..dfe88896b06c 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -67,7 +67,7 @@ UTS_MACHINE := $(OLDARCH) ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y) override CC += -mlittle-endian -ifneq ($(COMPILER),clang) +ifneq ($(cc-name),clang) override CC += -mno-strict-align endif override AS += -mlittle-endian @@ -333,7 +333,7 @@ TOUT := .tmp_gas_check # - Require gcc 4.0 or above on 64-bit # - gcc-4.2.0 has issues compiling modules on 64-bit checkbin: - @if test "${COMPILER}" != "clang" \ + @if test "$(cc-name)" != "clang" \ && test "$(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 '; \ @@ -342,14 +342,14 @@ checkbin: false; \ fi ; \ fi - @if test "${COMPILER}" != "clang" \ + @if test "$(cc-name)" != "clang" \ && test "$(cc-version)" -lt "0400" \ && test "x${CONFIG_PPC64}" = "xy" ; then \ echo -n "Sorry, GCC v4.0 or above is required to build " ; \ echo "the 64-bit powerpc kernel." ; \ false ; \ fi - @if test "${COMPILER}" != "clang" \ + @if test "$(cc-name)" != "clang" \ && test "$(cc-fullversion)" = "040200" \ && test "x${CONFIG_MODULES}${CONFIG_PPC64}" = "xyy" ; then \ echo -n '*** GCC-4.2.0 cannot compile the 64-bit powerpc ' ; \ diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index d3437b82ac25..3523df613391 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -128,6 +128,10 @@ cc-option-align = $(subst -functions=0,,\ cc-disable-warning = $(call try-run,\ $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) +# cc-name +# Expands to either gcc or clang +cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) + # cc-version cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index f734033af219..4efedcbe4165 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -56,7 +56,7 @@ endif KBUILD_CFLAGS += $(warning) else -ifeq ($(COMPILER),clang) +ifeq ($(cc-name),clang) KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides) KBUILD_CFLAGS += $(call cc-disable-warning, unused-value) KBUILD_CFLAGS += $(call cc-disable-warning, format) -- GitLab