Commit 09c9b61d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel 

Pull llvm patches from Behan Webster:
 "These are some initial updates to support compiling the kernel with
  clang.

  These patches have been through the proper reviews to the best of my
  ability, and have been soaking in linux-next for a few weeks.  These
  patches by themselves still do not completely allow clang to be used
  with the kernel code, but lay the foundation for other patches which
  are still under review.

  Several other of the LLVMLinux patches have been already added via
  maintainer trees"

* tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel:
  x86: LLVMLinux: Fix "incomplete type const struct x86cpu_device_id"
  x86 kbuild: LLVMLinux: More cc-options added for clang
  x86, acpi: LLVMLinux: Remove nested functions from Thinkpad ACPI
  LLVMLinux: Add support for clang to compiler.h and new compiler-clang.h
  LLVMLinux: Remove warning about returning an uninitialized variable
  kbuild: LLVMLinux: Fix LINUX_COMPILER definition script for compilation with clang
  Documentation: LLVMLinux: Update Documentation/dontdiff
  kbuild: LLVMLinux: Adapt warnings for compilation with clang
  kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
parents 141eaccd c4586256

Documentation/dontdiff

+3 −0
Original line number Diff line number Diff line 
*.a

*.aux

*.bc

*.bin

*.bz2

*.cis
@@ -21,6 +22,7 @@ 
*.i

*.jpeg

*.ko

*.ll

*.log

*.lst

*.lzma
@@ -35,6 +37,7 @@ 
*.out

*.patch

*.pdf

*.plist

*.png

*.pot

*.ps

Makefile

+29 −1
Original line number Diff line number Diff line
@@ -248,6 +248,11 @@ HOSTCXX = g++ 
HOSTCFLAGS   = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer

HOSTCXXFLAGS = -O2



ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)

HOSTCFLAGS  += -Wno-unused-value -Wno-unused-parameter \

		-Wno-missing-field-initializers -fno-delete-null-pointer-checks

endif



# Decide whether to build built-in, modular, or both.

# Normally, just do built-in.
@@ -324,6 +329,14 @@ endif 


export quiet Q KBUILD_VERBOSE



ifneq ($(CC),)

ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)

COMPILER := clang

else

COMPILER := gcc

endif

export COMPILER

endif



# Look for make include files relative to root of kernel src

MAKEFLAGS += --include-dir=$(srctree)
@@ -383,7 +396,7 @@ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ 
		   -fno-strict-aliasing -fno-common \

		   -Werror-implicit-function-declaration \

		   -Wno-format-security \

		   -fno-delete-null-pointer-checks

		   $(call cc-option,-fno-delete-null-pointer-checks,)

KBUILD_AFLAGS_KERNEL :=

KBUILD_CFLAGS_KERNEL :=

KBUILD_AFLAGS   := -D__ASSEMBLY__
@@ -623,9 +636,24 @@ endif 
endif

KBUILD_CFLAGS += $(stackp-flag)



ifeq ($(COMPILER),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)

KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)

KBUILD_CFLAGS += $(call cc-disable-warning, gnu)

# Quiet clang warning: comparison of unsigned expression < 0 is always false

KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)

# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the

# source of a reference will be _MergedGlobals and not on of the whitelisted names.

# See modpost pattern 2

KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)

else



# This warning generated too much noise in a regular build.

# Use make W=1 to enable this warning (see scripts/Makefile.build)

KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)

endif



ifdef CONFIG_FRAME_POINTER

KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls

arch/x86/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -108,7 +108,7 @@ else 


        # this works around some issues with generating unwind tables in older gccs

        # newer gccs do it by default

        KBUILD_CFLAGS += -maccumulate-outgoing-args

        KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args)

endif



# Make sure compiler does not have buggy stack-protector support.

include/asm-generic/cmpxchg-local.h

+2 −1
Original line number Diff line number Diff line
@@ -4,7 +4,8 @@ 
#include <linux/types.h>

#include <linux/irqflags.h>



extern unsigned long wrong_size_cmpxchg(volatile void *ptr);

extern unsigned long wrong_size_cmpxchg(volatile void *ptr)

	__noreturn;



/*

 * Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned

include/linux/compiler-clang.h

0 → 100644
+12 −0
Original line number Diff line number Diff line 
#ifndef __LINUX_COMPILER_H

#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."

#endif



/* Some compiler specific definitions are overwritten here

 * for Clang compiler

 */



#ifdef uninitialized_var

#undef uninitialized_var

#define uninitialized_var(x) x = *(&(x))

#endif

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