Merge tag 'kbuild-v4.12' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - improve Clang support

 - clean up various Makefiles

 - improve build log visibility (objtool, alpha, ia64)

 - improve compiler flag evaluation for better build performance

 - fix GCC version-dependent warning

 - fix genksyms

* tag 'kbuild-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (23 commits)
  kbuild: dtbinst: remove unnecessary __dtbs_install_prep target
  ia64: beatify build log for gate.so and gate-syms.o
  alpha: make short build log available for division routines
  alpha: merge build rules of division routines
  alpha: add $(src)/ rather than $(obj)/ to make source file path
  Makefile: evaluate LDFLAGS_BUILD_ID only once
  objtool: make it visible in make V=1 output
  kbuild: clang: add -no-integrated-as to KBUILD_[AC]FLAGS
  kbuild: Add support to generate LLVM assembly files
  kbuild: Add better clang cross build support
  kbuild: drop -Wno-unknown-warning-option from clang options
  kbuild: fix asm-offset generation to work with clang
  kbuild: consolidate redundant sed script ASM offset generation
  frv: Use OFFSET macro in DEF_*REG()
  kbuild: avoid conflict between -ffunction-sections and -pg on gcc-4.7
  kbuild: Consolidate header generation from ASM offset information
  kbuild: use -Oz instead of -Os when using clang
  kbuild, LLVMLinux: Add -Werror to cc-option to support clang
  Kbuild: make designated_init attribute fatal
  kbuild: drop unneeded patterns '.*.orig' and '.*.rej' from distclean
  ...

.gitignore

@@ -33,6 +33,7 @@
 *.lzo
 *.patch
 *.gcno
+*.ll
 modules.builtin
 Module.symvers
 *.dwo

Kbuild

@@ -7,31 +7,6 @@
 # 4) Check for missing system calls
 # 5) Generate constants.py (may need bounds.h)
 
-# Default sed regexp - multiline due to syntax constraints
-define sed-y
-	"/^->/{s:->#\(.*\):/* \1 */:; \
-	s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
-	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
-	s:->::; p;}"
-endef
-
-# Use filechk to avoid rebuilds when a header changes, but the resulting file
-# does not
-define filechk_offsets
-	(set -e; \
-	 echo "#ifndef $2"; \
-	 echo "#define $2"; \
-	 echo "/*"; \
-	 echo " * DO NOT MODIFY."; \
-	 echo " *"; \
-	 echo " * This file was generated by Kbuild"; \
-	 echo " */"; \
-	 echo ""; \
-	 sed -ne $(sed-y); \
-	 echo ""; \
-	 echo "#endif" )
-endef
-
 #####
 # 1) Generate bounds.h
 

Makefile

@@ -632,13 +632,9 @@ include arch/$(SRCARCH)/Makefile
 KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
 KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
 
-ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
-KBUILD_CFLAGS	+= $(call cc-option,-ffunction-sections,)
-KBUILD_CFLAGS	+= $(call cc-option,-fdata-sections,)
-endif
-
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS	+= -Os $(call cc-disable-warning,maybe-uninitialized,)
+KBUILD_CFLAGS	+= $(call cc-option,-Oz,-Os)
+KBUILD_CFLAGS	+= $(call cc-disable-warning,maybe-uninitialized,)
 else
 ifdef CONFIG_PROFILE_ALL_BRANCHES
 KBUILD_CFLAGS	+= -O2 $(call cc-disable-warning,maybe-uninitialized,)
@@ -698,8 +694,16 @@ endif
 KBUILD_CFLAGS += $(stackp-flag)
 
 ifeq ($(cc-name),clang)
+ifneq ($(CROSS_COMPILE),)
+CLANG_TARGET	:= -target $(notdir $(CROSS_COMPILE:%-=%))
+GCC_TOOLCHAIN	:= $(realpath $(dir $(shell which $(LD)))/..)
+endif
+ifneq ($(GCC_TOOLCHAIN),)
+CLANG_GCC_TC	:= -gcc-toolchain $(GCC_TOOLCHAIN)
+endif
+KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
+KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
 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)
@@ -710,10 +714,12 @@ KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 # See modpost pattern 2
 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
+KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
+KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
 else
 
 # These warnings generated too much noise in a regular build.
-# Use make W=1 to enable them (see scripts/Makefile.build)
+# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 endif
@@ -773,6 +779,11 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 endif
 
+ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
+KBUILD_CFLAGS	+= $(call cc-option,-ffunction-sections,)
+KBUILD_CFLAGS	+= $(call cc-option,-fdata-sections,)
+endif
+
 # 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)
@@ -801,6 +812,9 @@ KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)
 # enforce correct pointer usage
 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
 
+# Require designated initializers for all marked structures
+KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
+
 # use the deterministic mode of AR if available
 KBUILD_ARFLAGS := $(call ar-option,D)
 
@@ -815,7 +829,7 @@ KBUILD_AFLAGS   += $(ARCH_AFLAGS)   $(KAFLAGS)
 KBUILD_CFLAGS   += $(ARCH_CFLAGS)   $(KCFLAGS)
 
 # Use --build-id when available.
-LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
+LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
 			      $(call cc-ldoption, -Wl$(comma)--build-id,))
 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
@@ -1315,8 +1329,8 @@ PHONY += distclean
 distclean: mrproper
 	@find $(srctree) $(RCS_FIND_IGNORE) \
 		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
-		-o -name '*.bak' -o -name '#*#' -o -name '.*.orig' \
-		-o -name '.*.rej' -o -name '*%'  -o -name 'core' \) \
+		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
+		-o -name 'core' \) \
 		-type f -print | xargs rm -f
 
 
@@ -1361,6 +1375,8 @@ help:
 	@echo  '                    (default: $$(INSTALL_MOD_PATH)/lib/firmware)'
 	@echo  '  dir/            - Build all files in dir and below'
 	@echo  '  dir/file.[ois]  - Build specified target only'
+	@echo  '  dir/file.ll     - Build the LLVM assembly file'
+	@echo  '                    (requires compiler support for LLVM assembly generation)'
 	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
 	@echo  '                    (requires a recent binutils and recent build (System.map))'
 	@echo  '  dir/file.ko     - Build module including final link'
@@ -1549,6 +1565,7 @@ clean: $(clean-dirs)
 		-o -name '*.symtypes' -o -name 'modules.order' \
 		-o -name modules.builtin -o -name '.tmp_*.o.*' \
 		-o -name '*.c.[012]*.*' \
+		-o -name '*.ll' \
 		-o -name '*.gcno' \) -type f -print | xargs rm -f
 
 # Generate tags for editors
@@ -1652,6 +1669,8 @@ endif
 	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
 %.symtypes: %.c prepare scripts FORCE
 	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.ll: %.c prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
 
 # Modules
 /: prepare scripts FORCE

arch/alpha/lib/Makefile

@@ -46,11 +46,6 @@ AFLAGS___remqu.o =       -DREM
 AFLAGS___divlu.o = -DDIV       -DINTSIZE
 AFLAGS___remlu.o =       -DREM -DINTSIZE
 
-$(obj)/__divqu.o: $(obj)/$(ev6-y)divide.S
-	$(cmd_as_o_S)
-$(obj)/__remqu.o: $(obj)/$(ev6-y)divide.S
-	$(cmd_as_o_S)
-$(obj)/__divlu.o: $(obj)/$(ev6-y)divide.S
-	$(cmd_as_o_S)
-$(obj)/__remlu.o: $(obj)/$(ev6-y)divide.S
-	$(cmd_as_o_S)
+$(addprefix $(obj)/,__divqu.o __remqu.o __divlu.o __remlu.o): \
+						$(src)/$(ev6-y)divide.S FORCE
+	$(call if_changed_rule,as_o_S)

arch/frv/kernel/asm-offsets.c

@@ -14,21 +14,10 @@
 #include <asm/thread_info.h>
 #include <asm/gdb-stub.h>
 
-#define DEF_PTREG(sym, reg) \
-        asm volatile("\n->" #sym " %0 offsetof(struct pt_regs, " #reg ")" \
-		     : : "i" (offsetof(struct pt_regs, reg)))
-
-#define DEF_IREG(sym, reg) \
-        asm volatile("\n->" #sym " %0 offsetof(struct user_context, " #reg ")" \
-		     : : "i" (offsetof(struct user_context, reg)))
-
-#define DEF_FREG(sym, reg) \
-        asm volatile("\n->" #sym " %0 offsetof(struct user_context, " #reg ")" \
-		     : : "i" (offsetof(struct user_context, reg)))
-
-#define DEF_0REG(sym, reg) \
-        asm volatile("\n->" #sym " %0 offsetof(struct frv_frame0, " #reg ")" \
-		     : : "i" (offsetof(struct frv_frame0, reg)))
+#define DEF_PTREG(sym, reg) OFFSET(sym, pt_regs, reg)
+#define DEF_IREG(sym, reg) OFFSET(sym, user_context, reg)
+#define DEF_FREG(sym, reg) OFFSET(sym, user_context, reg)
+#define DEF_0REG(sym, reg) OFFSET(sym, frv_frame0, reg)
 
 void foo(void)
 {

arch/ia64/kernel/Makefile

@@ -50,32 +50,10 @@ CFLAGS_traps.o  += -mfixed-range=f2-f5,f16-f31
 # The gate DSO image is built using a special linker script.
 include $(src)/Makefile.gate
 
-# Calculate NR_IRQ = max(IA64_NATIVE_NR_IRQS, XEN_NR_IRQS, ...) based on config
-define sed-y
-	"/^->/{s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"
-endef
-quiet_cmd_nr_irqs = GEN     $@
-define cmd_nr_irqs
-	(set -e; \
-	 echo "#ifndef __ASM_NR_IRQS_H__"; \
-	 echo "#define __ASM_NR_IRQS_H__"; \
-	 echo "/*"; \
-	 echo " * DO NOT MODIFY."; \
-	 echo " *"; \
-	 echo " * This file was generated by Kbuild"; \
-	 echo " *"; \
-	 echo " */"; \
-	 echo ""; \
-	 sed -ne $(sed-y) $<; \
-	 echo ""; \
-	 echo "#endif" ) > $@
-endef
-
 # We use internal kbuild rules to avoid the "is up to date" message from make
 arch/$(SRCARCH)/kernel/nr-irqs.s: arch/$(SRCARCH)/kernel/nr-irqs.c
 	$(Q)mkdir -p $(dir $@)
 	$(call if_changed_dep,cc_s_c)
 
-include/generated/nr-irqs.h: arch/$(SRCARCH)/kernel/nr-irqs.s
-	$(Q)mkdir -p $(dir $@)
-	$(call cmd,nr_irqs)
+include/generated/nr-irqs.h: arch/$(SRCARCH)/kernel/nr-irqs.s FORCE
+	$(call filechk,offsets,__ASM_NR_IRQS_H__)

arch/ia64/kernel/Makefile.gate

@@ -6,7 +6,7 @@ extra-y += gate.so gate-syms.o gate.lds gate.o
 
 CPPFLAGS_gate.lds := -P -C -U$(ARCH)
 
-quiet_cmd_gate = GATE $@
+quiet_cmd_gate = GATE    $@
       cmd_gate = $(CC) -nostdlib $(GATECFLAGS_$(@F)) -Wl,-T,$(filter-out FORCE,$^) -o $@
 
 GATECFLAGS_gate.so = -shared -s -Wl,-soname=linux-gate.so.1 \

include/linux/kbuild.h

@@ -2,14 +2,14 @@
 #define __LINUX_KBUILD_H
 
 #define DEFINE(sym, val) \
-        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+	asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val))
 
-#define BLANK() asm volatile("\n->" : : )
+#define BLANK() asm volatile("\n.ascii \"->\"" : : )
 
 #define OFFSET(sym, str, mem) \
 	DEFINE(sym, offsetof(struct str, mem))
 
 #define COMMENT(x) \
-	asm volatile("\n->#" x)
+	asm volatile("\n.ascii \"->#" x "\"")
 
 #endif

scripts/Kbuild.include

@@ -116,12 +116,12 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign
@@ -131,7 +131,7 @@ cc-option-align = $(subst -functions=0,,\
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 cc-disable-warning = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 
 # cc-name
 # Expands to either gcc or clang

scripts/Makefile.build

@@ -177,6 +177,14 @@ cmd_cc_symtypes_c =                                                         \
 $(obj)/%.symtypes : $(src)/%.c FORCE
 	$(call cmd,cc_symtypes_c)
 
+# LLVM assembly
+# Generate .ll files from .c
+quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
+      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
+
+$(obj)/%.ll: $(src)/%.c FORCE
+	$(call if_changed_dep,cc_ll_c)
+
 # C (.c) files
 # The C file is compiled and updated dependency information is generated.
 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
@@ -272,14 +280,14 @@ define rule_cc_o_c
 	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
 	$(call cmd_and_fixdep,cc_o_c)					  \
 	$(cmd_modversions_c)						  \
-	$(cmd_objtool)						          \
+	$(call echo-cmd,objtool) $(cmd_objtool)				  \
 	$(call echo-cmd,record_mcount) $(cmd_record_mcount)
 endef
 
 define rule_as_o_S
 	$(call cmd_and_fixdep,as_o_S)					  \
 	$(cmd_modversions_S)						  \
-	$(cmd_objtool)
+	$(call echo-cmd,objtool) $(cmd_objtool)
 endef
 
 # List module undefined symbols (or empty line if not enabled)

scripts/Makefile.dtbinst

@@ -20,12 +20,6 @@ include include/config/auto.conf
 include scripts/Kbuild.include
 include $(src)/Makefile
 
-PHONY += __dtbs_install_prep
-__dtbs_install_prep:
-ifeq ("$(dtbinst-root)", "$(obj)")
-	$(Q)mkdir -p $(INSTALL_DTBS_PATH)
-endif
-
 dtbinst-files	:= $(dtb-y)
 dtbinst-dirs	:= $(dts-dirs)
 
@@ -35,8 +29,6 @@ quiet_cmd_dtb_install =	INSTALL $<
 
 install-dir = $(patsubst $(dtbinst-root)%,$(INSTALL_DTBS_PATH)%,$(obj))
 
-$(dtbinst-files) $(dtbinst-dirs): | __dtbs_install_prep
-
 $(dtbinst-files): %.dtb: $(obj)/%.dtb
 	$(call cmd,dtb_install,$(install-dir))
 

scripts/Makefile.extrawarn

@@ -64,7 +64,6 @@ 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)
-KBUILD_CFLAGS += $(call cc-disable-warning, unknown-warning-option)
 KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
 KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
 KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)

scripts/Makefile.lib

@@ -420,3 +420,34 @@ quiet_cmd_xzmisc = XZMISC  $@
 cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
 	xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
 	(rm -f $@ ; false)
+
+# ASM offsets
+# ---------------------------------------------------------------------------
+
+# Default sed regexp - multiline due to syntax constraints
+#
+# Use [:space:] because LLVM's integrated assembler inserts <tab> around
+# the .ascii directive whereas GCC keeps the <space> as-is.
+define sed-offsets
+	's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
+	/^->/{s:->#\(.*\):/* \1 */:; \
+	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
+	s:->::; p;}'
+endef
+
+# Use filechk to avoid rebuilds when a header changes, but the resulting file
+# does not
+define filechk_offsets
+	(set -e; \
+	 echo "#ifndef $2"; \
+	 echo "#define $2"; \
+	 echo "/*"; \
+	 echo " * DO NOT MODIFY."; \
+	 echo " *"; \
+	 echo " * This file was generated by Kbuild"; \
+	 echo " */"; \
+	 echo ""; \
+	 sed -ne $(sed-offsets); \
+	 echo ""; \
+	 echo "#endif" )
+endef