On architectures that setup CROSS_COMPILE in their arch/*/Makefile (arc, blackfin, m68k, mips, parisc, score, sh, tile, unicore32, xtensa), cc-option and cc-disable-warning may check against the wrong compiler, causing errors like cc1: error: unrecognized command line option "-Wno-maybe-uninitialized" if the host gcc supports a compiler option, while the cross compiler doesn't support that option. Move all logic using cc-option or cc-disable-warning below the inclusion of the arch's Makefile to fix this. Introduced by - commit e74fc973b6e531fef1fce8b101ffff05ecfb774c ("Turn off -Wmaybe-uninitialized when building with -Os"), - commit 61163efae02040f66a95c8ed17f4407951ba58fa ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang"). As -Wno-maybe-uninitialized requires a quite recent gcc (gcc 4.6.3 on Ubuntu 12.04 LTS doesn't support it), this only showed up recently (gcc 4.8.2 on Ubuntu 14.04 LTS does support it). Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> --- Perhaps all KBUILD_* definitions can be moved below the inclusion of the arch's Makefile, to make it less likely to happen again? But that's definitely post-3.15 material. Makefile | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/Makefile b/Makefile index cf3412d78ff1..da910e09fc9a 100644 --- a/Makefile +++ b/Makefile @@ -395,8 +395,8 @@ KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common \ -Werror-implicit-function-declaration \ - -Wno-format-security \ - $(call cc-option,-fno-delete-null-pointer-checks,) + -Wno-format-security + KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := KBUILD_AFLAGS := -D__ASSEMBLY__ @@ -594,14 +594,16 @@ endif # $(dot-config) # Defaults to vmlinux, but the arch makefile usually adds further targets all: vmlinux +include $(srctree)/arch/$(SRCARCH)/Makefile + +KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) + ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,) else KBUILD_CFLAGS += -O2 endif -include $(srctree)/arch/$(SRCARCH)/Makefile - ifdef CONFIG_READABLE_ASM # Disable optimizations that make assembler listings hard to read. # reorder blocks reorders the control in the function -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html