From 278ae6040397f37fa6a96a6b86ed02d4762080a7 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 22 Sep 2017 14:31:13 +0900 Subject: kbuild: link-vmlinux.sh: simplify .version increment Since commit 1f2bfbd00e46 ("kbuild: link of vmlinux moved to a script"), it is easy to increment .version without using a temporary file .old_version. I do not see anybody who creates the .tmp_version. Probably it is a left-over of commit 4e25d8bb9550fb ("[PATCH] kbuild: adjust .version updating"). Just remove it. Signed-off-by: Masahiro Yamada --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index cf007a31d575..9aa47218100e 100644 --- a/Makefile +++ b/Makefile @@ -1278,7 +1278,7 @@ CLEAN_DIRS += $(MODVERDIR) # Directories & files removed with 'make mrproper' MRPROPER_DIRS += include/config usr/include include/generated \ arch/*/include/generated .tmp_objdiff -MRPROPER_FILES += .config .config.old .version .old_version \ +MRPROPER_FILES += .config .config.old .version \ Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \ signing_key.pem signing_key.priv signing_key.x509 \ x509.genkey extra_certificates signing_key.x509.keyid \ -- cgit v1.2.3 From 9d022c540606a5a8ae5d1cc02fc12de362ba4585 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 4 Oct 2017 12:56:04 +0900 Subject: kbuild: replace $(hdr-arch) with $(SRCARCH) Since commit 5e53879008b9 ("sparc,sparc64: unify Makefile"), hdr-arch and SRCARCH always match. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- Makefile | 21 +++++++++------------ scripts/Makefile.headersinst | 2 +- 2 files changed, 10 insertions(+), 13 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 9aa47218100e..27fcdc1d4ec9 100644 --- a/Makefile +++ b/Makefile @@ -283,9 +283,6 @@ ifeq ($(ARCH),tilegx) SRCARCH := tile endif -# Where to locate arch specific headers -hdr-arch := $(SRCARCH) - KCONFIG_CONFIG ?= .config export KCONFIG_CONFIG @@ -378,8 +375,8 @@ CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ - -I$(srctree)/arch/$(hdr-arch)/include/uapi \ - -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \ + -I$(srctree)/arch/$(SRCARCH)/include/uapi \ + -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \ -I$(srctree)/include/uapi \ -I$(objtree)/include/generated/uapi \ -include $(srctree)/include/linux/kconfig.h @@ -387,8 +384,8 @@ USERINCLUDE := \ # Use LINUXINCLUDE when you must reference the include/ directory. # Needed to be compatible with the O= option LINUXINCLUDE := \ - -I$(srctree)/arch/$(hdr-arch)/include \ - -I$(objtree)/arch/$(hdr-arch)/include/generated \ + -I$(srctree)/arch/$(SRCARCH)/include \ + -I$(objtree)/arch/$(SRCARCH)/include/generated \ $(if $(KBUILD_SRC), -I$(srctree)/include) \ -I$(objtree)/include \ $(USERINCLUDE) @@ -1134,8 +1131,8 @@ headerdep: #Default location for installed headers export INSTALL_HDR_PATH = $(objtree)/usr -# If we do an all arch process set dst to include/arch-$(hdr-arch) -hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include) +# If we do an all arch process set dst to include/arch-$(SRCARCH) +hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include) PHONY += archheaders archheaders: @@ -1153,10 +1150,10 @@ headers_install_all: PHONY += headers_install headers_install: __headers - $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \ + $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \ $(error Headers not exportable for the $(SRCARCH) architecture)) $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include - $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) + $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) PHONY += headers_check_all headers_check_all: headers_install_all @@ -1165,7 +1162,7 @@ headers_check_all: headers_install_all PHONY += headers_check headers_check: headers_install $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1 - $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1 + $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1 # --------------------------------------------------------------------------- # Kernel selftest diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst index 343d586e566e..5692d7a66163 100644 --- a/scripts/Makefile.headersinst +++ b/scripts/Makefile.headersinst @@ -30,7 +30,7 @@ __headers: $(subdirs) $(subdirs): $(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(dst)/$@ -# Skip header install/check for include/uapi and arch/$(hdr-arch)/include/uapi. +# Skip header install/check for include/uapi and arch/$(SRCARCH)/include/uapi. # We have only sub-directories there. skip-inst := $(if $(filter %/uapi,$(obj)),1) -- cgit v1.2.3 From ba634eceb535d95e87ef09caae7814b3687c6036 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 4 Oct 2017 12:56:05 +0900 Subject: kbuild: move "_all" target out of $(KBUILD_SRC) conditional The first "_all" occurrence around line 120 is only visible when KBUILD_SRC is unset. If O=... is specified, the working directory is relocated, then the only second occurrence around line 193 is visible, that is not set to PHONY. Move the first one to an always visible place. This clarifies "_all" is our default target and it is always set to PHONY. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 27fcdc1d4ec9..a793ed153f7a 100644 --- a/Makefile +++ b/Makefile @@ -10,6 +10,10 @@ NAME = Fearless Coyote # Comments in this file are targeted only to the developer, do not # expect to learn how to build the kernel reading this file. +# That's our default target when none is given on the command line +PHONY := _all +_all: + # o Do not use make's built-in rules and variables # (this increases performance and avoids hard-to-debug behaviour); # o Look for make include files relative to root of kernel src @@ -116,10 +120,6 @@ ifeq ("$(origin O)", "command line") KBUILD_OUTPUT := $(O) endif -# That's our default target when none is given on the command line -PHONY := _all -_all: - # Cancel implicit rules on top Makefile $(CURDIR)/Makefile Makefile: ; -- cgit v1.2.3 From 2c1f4f125159f10521944cea23e33a00fcf85ede Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 4 Oct 2017 12:56:06 +0900 Subject: kbuild: re-order the code to not parse unnecessary variables The top Makefile is divided into some sections such as mixed targets, config targets, build targets, etc. When we build mixed targets, Kbuild just invokes submake to process them one by one. In this case, compiler-related variables like CC, KBUILD_CFLAGS, etc. are unneeded. Check what kind of targets we are building first, and parse variables for building only when necessary. Signed-off-by: Masahiro Yamada --- Makefile | 233 ++++++++++++++++++++++++++++++++------------------------------- 1 file changed, 118 insertions(+), 115 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index a793ed153f7a..1ec97b902e52 100644 --- a/Makefile +++ b/Makefile @@ -186,15 +186,6 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif -# If building an external module we do not care about the all: rule -# but instead _all depend on modules -PHONY += all -ifeq ($(KBUILD_EXTMOD),) -_all: all -else -_all: modules -endif - ifeq ($(KBUILD_SRC),) # building in the source tree srctree := . @@ -206,6 +197,9 @@ else srctree := $(KBUILD_SRC) endif endif + +export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC + objtree := . src := $(srctree) obj := $(objtree) @@ -214,6 +208,74 @@ VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD)) export srctree objtree VPATH +# To make sure we do not include .config for any of the *config targets +# catch them early, and hand them over to scripts/kconfig/Makefile +# It is allowed to specify more targets when calling make, including +# mixing *config targets and build targets. +# For example 'make oldconfig all'. +# Detect when mixed targets is specified, and make a second invocation +# of make so .config is not included in this case either (for *config). + +version_h := include/generated/uapi/linux/version.h +old_version_h := include/linux/version.h + +no-dot-config-targets := clean mrproper distclean \ + cscope gtags TAGS tags help% %docs check% coccicheck \ + $(version_h) headers_% archheaders archscripts \ + kernelversion %src-pkg + +config-targets := 0 +mixed-targets := 0 +dot-config := 1 + +ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) + ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) + dot-config := 0 + endif +endif + +ifeq ($(KBUILD_EXTMOD),) + ifneq ($(filter config %config,$(MAKECMDGOALS)),) + config-targets := 1 + ifneq ($(words $(MAKECMDGOALS)),1) + mixed-targets := 1 + endif + endif +endif +# install and modules_install need also be processed one by one +ifneq ($(filter install,$(MAKECMDGOALS)),) + ifneq ($(filter modules_install,$(MAKECMDGOALS)),) + mixed-targets := 1 + endif +endif + +ifeq ($(mixed-targets),1) +# =========================================================================== +# We're called with mixed targets (*config and build targets). +# Handle them one by one. + +PHONY += $(MAKECMDGOALS) __build_one_by_one + +$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one + @: + +__build_one_by_one: + $(Q)set -e; \ + for i in $(MAKECMDGOALS); do \ + $(MAKE) -f $(srctree)/Makefile $$i; \ + done + +else + +# We need some generic definitions (do not try to remake the file). +scripts/Kbuild.include: ; +include scripts/Kbuild.include + +# Read KERNELRELEASE from include/config/kernel.release (if it exists) +KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null) +KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION) +export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION + # SUBARCH tells the usermode build what the underlying arch is. That is set # first, and if a usermode build is happening, the "ARCH=um" on the command # line overrides the setting of ARCH below. If a native build is happening, @@ -308,40 +370,6 @@ 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. - -KBUILD_MODULES := -KBUILD_BUILTIN := 1 - -# If we have only "make modules", don't compile built-in objects. -# When we're building modules with modversions, we need to consider -# the built-in objects during the descend as well, in order to -# make sure the checksums are up to date before we record them. - -ifeq ($(MAKECMDGOALS),modules) - KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) -endif - -# If we have "make modules", compile modules -# in addition to whatever we do anyway. -# Just "make" or "make all" shall build modules as well - -ifneq ($(filter all _all modules,$(MAKECMDGOALS)),) - KBUILD_MODULES := 1 -endif - -ifeq ($(MAKECMDGOALS),) - KBUILD_MODULES := 1 -endif - -export KBUILD_MODULES KBUILD_BUILTIN -export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD - -# We need some generic definitions (do not try to remake the file). -scripts/Kbuild.include: ; -include scripts/Kbuild.include - # Make variables (CC, etc...) AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld @@ -406,11 +434,6 @@ KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds -# Read KERNELRELEASE from include/config/kernel.release (if it exists) -KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null) -KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION) - -export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE @@ -459,73 +482,6 @@ ifneq ($(KBUILD_SRC),) $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL) endif -# Support for using generic headers in asm-generic -PHONY += asm-generic uapi-asm-generic -asm-generic: uapi-asm-generic - $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ - src=asm obj=arch/$(SRCARCH)/include/generated/asm -uapi-asm-generic: - $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ - src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm - -# To make sure we do not include .config for any of the *config targets -# catch them early, and hand them over to scripts/kconfig/Makefile -# It is allowed to specify more targets when calling make, including -# mixing *config targets and build targets. -# For example 'make oldconfig all'. -# Detect when mixed targets is specified, and make a second invocation -# of make so .config is not included in this case either (for *config). - -version_h := include/generated/uapi/linux/version.h -old_version_h := include/linux/version.h - -no-dot-config-targets := clean mrproper distclean \ - cscope gtags TAGS tags help% %docs check% coccicheck \ - $(version_h) headers_% archheaders archscripts \ - kernelversion %src-pkg - -config-targets := 0 -mixed-targets := 0 -dot-config := 1 - -ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) - ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) - dot-config := 0 - endif -endif - -ifeq ($(KBUILD_EXTMOD),) - ifneq ($(filter config %config,$(MAKECMDGOALS)),) - config-targets := 1 - ifneq ($(words $(MAKECMDGOALS)),1) - mixed-targets := 1 - endif - endif -endif -# install and modules_install need also be processed one by one -ifneq ($(filter install,$(MAKECMDGOALS)),) - ifneq ($(filter modules_install,$(MAKECMDGOALS)),) - mixed-targets := 1 - endif -endif - -ifeq ($(mixed-targets),1) -# =========================================================================== -# We're called with mixed targets (*config and build targets). -# Handle them one by one. - -PHONY += $(MAKECMDGOALS) __build_one_by_one - -$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one - @: - -__build_one_by_one: - $(Q)set -e; \ - for i in $(MAKECMDGOALS); do \ - $(MAKE) -f $(srctree)/Makefile $$i; \ - done - -else ifeq ($(config-targets),1) # =========================================================================== # *config targets only - make sure prerequisites are updated, and descend @@ -548,6 +504,44 @@ else # Build targets only - this includes vmlinux, arch specific targets, clean # targets and others. In general all targets except *config targets. +# If building an external module we do not care about the all: rule +# but instead _all depend on modules +PHONY += all +ifeq ($(KBUILD_EXTMOD),) +_all: all +else +_all: modules +endif + +# Decide whether to build built-in, modular, or both. +# Normally, just do built-in. + +KBUILD_MODULES := +KBUILD_BUILTIN := 1 + +# If we have only "make modules", don't compile built-in objects. +# When we're building modules with modversions, we need to consider +# the built-in objects during the descend as well, in order to +# make sure the checksums are up to date before we record them. + +ifeq ($(MAKECMDGOALS),modules) + KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) +endif + +# If we have "make modules", compile modules +# in addition to whatever we do anyway. +# Just "make" or "make all" shall build modules as well + +ifneq ($(filter all _all modules,$(MAKECMDGOALS)),) + KBUILD_MODULES := 1 +endif + +ifeq ($(MAKECMDGOALS),) + KBUILD_MODULES := 1 +endif + +export KBUILD_MODULES KBUILD_BUILTIN + ifeq ($(KBUILD_EXTMOD),) # Additional helpers built in scripts/ # Carefully list dependencies so we do not try to build scripts twice @@ -1063,6 +1057,15 @@ prepare0: archprepare gcc-plugins # All the preparing.. prepare: prepare0 prepare-objtool +# Support for using generic headers in asm-generic +PHONY += asm-generic uapi-asm-generic +asm-generic: uapi-asm-generic + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ + src=asm obj=arch/$(SRCARCH)/include/generated/asm +uapi-asm-generic: + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \ + src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm + PHONY += prepare-objtool prepare-objtool: $(objtool_target) -- cgit v1.2.3 From df16aaac26e92e97ab7234d3f93c953466adc4b5 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Sat, 7 Oct 2017 13:23:23 -0700 Subject: kbuild: clang: remove crufty HOSTCFLAGS When compiling with `make CC=clang HOSTCC=clang`, I was seeing warnings that clang did not recognize -fno-delete-null-pointer-checks for HOSTCC targets. These were added in commit 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang"). Clang does not support -fno-delete-null-pointer-checks, so adding it to HOSTCFLAGS if HOSTCC is clang does not make sense. It's not clear why the other warnings were disabled, and just for HOSTCFLAGS, but I can remove them, add -Werror to HOSTCFLAGS and compile with clang just fine. Suggested-by: Masahiro Yamada Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada --- Makefile | 5 ----- 1 file changed, 5 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 1ec97b902e52..1254719958ca 100644 --- a/Makefile +++ b/Makefile @@ -365,11 +365,6 @@ HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) HOST_LOADLIBES := $(HOST_LFS_LIBS) -ifeq ($(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 - # Make variables (CC, etc...) AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld -- cgit v1.2.3 From 3298b690b21cdbe6b2ae8076d9147027f396f2b1 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Mon, 16 Oct 2017 10:12:45 -0700 Subject: kbuild: Add a cache for generated variables While timing a "no-op" build of the kernel (incrementally building the kernel even though nothing changed) in the Chrome OS build system I found that it was much slower than I expected. Digging into things a bit, I found that quite a bit of the time was spent invoking the C compiler even though we weren't actually building anything. Currently in the Chrome OS build system the C compiler is called through a number of wrappers (one of which is written in python!) and can take upwards of 100 ms to invoke even if we're not doing anything difficult, so these invocations of the compiler were taking a lot of time. Worse the invocations couldn't seem to take advantage of the multiple cores on my system. Certainly it seems like we could make the compiler invocations in the Chrome OS build system faster, but only to a point. Inherently invoking a program as big as a C compiler is a fairly heavy operation. Thus even if we can speed the compiler calls it made sense to track down what was happening. It turned out that all the compiler invocations were coming from usages like this in the kernel's Makefile: KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) Due to the way cc-option and similar statements work the above contains an implicit call to the C compiler. ...and due to the fact that we're storing the result in KBUILD_CFLAGS, a simply expanded variable, the call will happen every time the Makefile is parsed, even if there are no users of KBUILD_CFLAGS. Rather than redoing this computation every time, it makes a lot of sense to cache the result of all of the Makefile's compiler calls just like we do when we compile a ".c" file to a ".o" file. Conceptually this is quite a simple idea. ...and since the calls to invoke the compiler and similar tools are centrally located in the Kbuild.include file this doesn't even need to be super invasive. Implementing the cache in a simple-to-use and efficient way is not quite as simple as it first sounds, though. To get maximum speed we really want the cache in a format that make can natively understand and make doesn't really have an ability to load/parse files. ...but make _can_ import other Makefiles, so the solution is to store the cache in Makefile format. This requires coming up with a valid/unique Makefile variable name for each value to be cached, but that's solvable with some cleverness. After this change, we'll automatically create a ".cache.mk" file that will contain our cached variables. We'll load this on each invocation of make and will avoid recomputing anything that's already in our cache. The cache is stored in a format that it shouldn't need any invalidation since anything that might change should affect the "key" and any old cached value won't be used. Signed-off-by: Douglas Anderson Tested-by: Ingo Molnar Tested-by: Guenter Roeck Signed-off-by: Masahiro Yamada --- Makefile | 1 + scripts/Kbuild.include | 90 ++++++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 77 insertions(+), 14 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 1254719958ca..5be2c8d2ce73 100644 --- a/Makefile +++ b/Makefile @@ -1545,6 +1545,7 @@ clean: $(clean-dirs) -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name modules.builtin -o -name '.tmp_*.o.*' \ + -o -name .cache.mk \ -o -name '*.c.[012]*.*' \ -o -name '*.ll' \ -o -name '*.gcno' \) -type f -print | xargs rm -f diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 9ffd3dda3889..dfadb1c94368 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -8,6 +8,8 @@ squote := ' empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ +right_paren := ) +left_paren := ( ### # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o @@ -80,6 +82,60 @@ cc-cross-prefix = \ echo $(c); \ fi))) +# Tools for caching Makefile variables that are "expensive" to compute. +# +# Here we want to help deal with variables that take a long time to compute +# by making it easy to store these variables in a cache. +# +# The canonical example here is testing for compiler flags. On a simple system +# each call to the compiler takes 10 ms, but on a system with a compiler that's +# called through various wrappers it can take upwards of 100 ms. If we have +# 100 calls to the compiler this can take 1 second (on a simple system) or 10 +# seconds (on a complicated system). +# +# The "cache" will be in Makefile syntax and can be directly included. +# Any time we try to reference a variable that's not in the cache we'll +# calculate it and store it in the cache for next time. + +# Include values from last time +make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk +ifeq ($(wildcard $(dir $(make-cache))),) +$(shell mkdir -p '$(dir $(make-cache))') +endif +$(make-cache): ; +-include $(make-cache) + +# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) +# +# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' +__sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$(subst \,_,$(subst =,_,$(subst $(space),_,$(subst $(comma),_,$(subst :,_,$(1))))))))) + +# Usage: $(call shell-cached,shell_command) +# Example: $(call shell-cached,md5sum /usr/bin/gcc) +# +# If we've already seen a call to this exact shell command (even in a +# previous invocation of make!) we'll return the value. If not, we'll +# compute it and store the result for future runs. +# +# This is a bit of voodoo, but basic explanation is that if the variable +# was undefined then we'll evaluate the shell command and store the result +# into the variable. We'll then store that value in the cache and finally +# output the value. +# +# NOTE: The $$(2) here isn't actually a parameter to __run-and-store. We +# happen to know that the caller will have their shell command in $(2) so the +# result of "call"ing this will produce a reference to that $(2). The reason +# for this strangeness is to avoid an extra level of eval (and escaping) of +# $(2). +define __run-and-store +ifeq ($(origin $(1)),undefined) + $$(eval $(1) := $$(shell $$(2))) + $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) +endif +endef +__shell-cached = $(eval $(call __run-and-store,$(1)))$($(1)) +shell-cached = $(call __shell-cached,__cached_$(call __sanitize-opt,$(1)),$(1)) + # output directory for tests below TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) @@ -87,30 +143,36 @@ TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) # Exit code chooses option. "$$TMP" serves as a temporary file and is # automatically cleaned up. -try-run = $(shell set -e; \ +__try-run = set -e; \ TMP="$(TMPOUT).$$$$.tmp"; \ TMPO="$(TMPOUT).$$$$.o"; \ if ($(1)) >/dev/null 2>&1; \ then echo "$(2)"; \ else echo "$(3)"; \ fi; \ - rm -f "$$TMP" "$$TMPO") + rm -f "$$TMP" "$$TMPO" + +try-run = $(shell $(__try-run)) + +# try-run-cached +# This works like try-run, but the result is cached. +try-run-cached = $(call shell-cached,$(__try-run)) # as-option # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) -as-option = $(call try-run,\ +as-option = $(call try-run-cached,\ $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) # as-instr # Usage: cflags-y += $(call as-instr,instr,option1,option2) -as-instr = $(call try-run,\ +as-instr = $(call try-run-cached,\ printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) # __cc-option # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) -__cc-option = $(call try-run,\ +__cc-option = $(call try-run-cached,\ $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) # Do not attempt to build with gcc plugins during cc-option tests. @@ -130,23 +192,23 @@ hostcc-option = $(call __cc-option, $(HOSTCC),\ # cc-option-yn # Usage: flag := $(call cc-option-yn,-march=winchip-c6) -cc-option-yn = $(call try-run,\ +cc-option-yn = $(call try-run-cached,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) # cc-disable-warning # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) -cc-disable-warning = $(call try-run,\ +cc-disable-warning = $(call try-run-cached,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) # cc-name # Expands to either gcc or clang -cc-name = $(shell $(CC) -v 2>&1 | grep -q "clang version" && echo clang || echo gcc) +cc-name = $(call shell-cached,$(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)) +cc-version = $(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) # cc-fullversion -cc-fullversion = $(shell $(CONFIG_SHELL) \ +cc-fullversion = $(call shell-cached,$(CONFIG_SHELL) \ $(srctree)/scripts/gcc-version.sh -p $(CC)) # cc-ifversion @@ -159,22 +221,22 @@ cc-if-fullversion = $(shell [ $(cc-fullversion) $(1) $(2) ] && echo $(3) || echo # cc-ldoption # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both) -cc-ldoption = $(call try-run,\ +cc-ldoption = $(call try-run-cached,\ $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) # ld-option # Usage: LDFLAGS += $(call ld-option, -X) -ld-option = $(call try-run,\ +ld-option = $(call try-run-cached,\ $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) # ar-option # Usage: KBUILD_ARFLAGS := $(call ar-option,D) # Important: no spaces around options -ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) +ar-option = $(call try-run-cached, $(AR) rc$(1) "$$TMP",$(1),$(2)) # ld-version # Note this is mainly for HJ Lu's 3 number binutil versions -ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) +ld-version = $(call shell-cached,$(LD) --version | $(srctree)/scripts/ld-version.sh) # ld-ifversion # Usage: $(call ld-ifversion, -ge, 22252, y) -- cgit v1.2.3 From 4e56207130eda9a27df116623e2fce7cca2c6764 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Mon, 16 Oct 2017 10:12:46 -0700 Subject: kbuild: Cache a few more calls to the compiler These are a few stragglers that I left out of the original patch to cache calls to the C compiler ("kbuild: Add a cache for generated variables") because they bleed out into the main Makefile and thus uglify things a little bit. The idea is the same here, though. Signed-off-by: Douglas Anderson Tested-by: Ingo Molnar Tested-by: Guenter Roeck Signed-off-by: Masahiro Yamada --- Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 5be2c8d2ce73..d3e6fccfad9b 100644 --- a/Makefile +++ b/Makefile @@ -638,7 +638,7 @@ KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \ KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) # check for 'asm goto' -ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) +ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO endif @@ -774,7 +774,7 @@ 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) +NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include) CHECKFLAGS += $(NOSTDINC_FLAGS) # warn about C99 declaration after statement -- cgit v1.2.3 From 433dc2ebe7d17dd21cba7ad5c362d37323592236 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 12 Oct 2017 18:22:25 +0900 Subject: kbuild: do not call cc-option before KBUILD_CFLAGS initialization Some $(call cc-option,...) are invoked very early, even before KBUILD_CFLAGS, etc. are initialized. The returned string from $(call cc-option,...) depends on KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS. Since they are exported, they are not empty when the top Makefile is recursively invoked. The recursion occurs in several places. For example, the top Makefile invokes itself for silentoldconfig. "make tinyconfig", "make rpm-pkg" are the cases, too. In those cases, the second call of cc-option from the same line runs a different shell command due to non-pristine KBUILD_CFLAGS. To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS must be initialized before any call of cc-option. This avoids garbage data in the .cache.mk file. Move all calls of cc-option below the config targets because target compiler flags are unnecessary for Kconfig. Signed-off-by: Masahiro Yamada Reviewed-by: Douglas Anderson --- Makefile | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index d3e6fccfad9b..a7476e6934f1 100644 --- a/Makefile +++ b/Makefile @@ -392,9 +392,6 @@ LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = -CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) -CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) - # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ @@ -413,21 +410,19 @@ LINUXINCLUDE := \ -I$(objtree)/include \ $(USERINCLUDE) -KBUILD_CPPFLAGS := -D__KERNEL__ - +KBUILD_AFLAGS := -D__ASSEMBLY__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common -fshort-wchar \ -Werror-implicit-function-declaration \ -Wno-format-security \ - -std=gnu89 $(call cc-option,-fno-PIE) - - + -std=gnu89 +KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := -KBUILD_AFLAGS := -D__ASSEMBLY__ $(call cc-option,-fno-PIE) KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds +GCC_PLUGINS_CFLAGS := export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES @@ -435,7 +430,7 @@ export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS -export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN +export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_KASAN CFLAGS_UBSAN export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL @@ -607,6 +602,12 @@ endif # Defaults to vmlinux, but the arch makefile usually adds further targets all: vmlinux +KBUILD_CFLAGS += $(call cc-option,-fno-PIE) +KBUILD_AFLAGS += $(call cc-option,-fno-PIE) +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,) +CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) +export CFLAGS_GCOV CFLAGS_KCOV + # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default # values of the respective KBUILD_* variables ARCH_CPPFLAGS := -- cgit v1.2.3 From 2982c953570b2bced858613d70443c2c6a90587b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 13 Nov 2017 19:29:35 +0900 Subject: kbuild: remove redundant $(wildcard ...) for cmd_files calculation I do not see any reason why $(wildcard ...) needs to be called twice for computing cmd_files. Remove the first one. Signed-off-by: Masahiro Yamada --- Makefile | 3 +-- scripts/Makefile.build | 3 +-- scripts/Makefile.headersinst | 3 +-- scripts/Makefile.modpost | 3 +-- 4 files changed, 4 insertions(+), 8 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index a7476e6934f1..58dd24520c9e 100644 --- a/Makefile +++ b/Makefile @@ -1693,8 +1693,7 @@ cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \ # read all saved command lines -targets := $(wildcard $(sort $(targets))) -cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) +cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) $(cmd_files): ; # Do not try to update included dependency files diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 061d0c3a420a..62d5314c3b71 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -583,8 +583,7 @@ FORCE: # optimization, we don't need to read them if the target does not # exist, we will rebuild anyway in that case. -targets := $(wildcard $(sort $(targets))) -cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) +cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) include $(cmd_files) diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst index 5692d7a66163..c6fb2b75d813 100644 --- a/scripts/Makefile.headersinst +++ b/scripts/Makefile.headersinst @@ -114,9 +114,8 @@ $(check-file): scripts/headers_check.pl $(output-files) FORCE endif -targets := $(wildcard $(sort $(targets))) cmd_files := $(wildcard \ - $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) + $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) include $(cmd_files) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 16923ba4b5b1..cf125c11ca41 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -143,8 +143,7 @@ FORCE: # optimization, we don't need to read them if the target does not # exist, we will rebuild anyway in that case. -targets := $(wildcard $(sort $(targets))) -cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) +cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),) include $(cmd_files) -- cgit v1.2.3 From 7f855fc805cd9c29867aed56cc20f818b36a7b7b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 14 Nov 2017 18:47:20 +0900 Subject: kbuild: move coccicheck help from scripts/Makefile.help to top Makefile In my view, it is not helpful to have a separate file just for the coccicheck help message. Merge scripts/Makefile.help into the top-level Makefile. Signed-off-by: Masahiro Yamada Acked-by: Julia Lawall --- Makefile | 2 +- scripts/Makefile.help | 3 --- 2 files changed, 1 insertion(+), 4 deletions(-) delete mode 100644 scripts/Makefile.help (limited to 'Makefile') diff --git a/Makefile b/Makefile index 58dd24520c9e..06a5798335fc 100644 --- a/Makefile +++ b/Makefile @@ -1384,7 +1384,7 @@ help: @echo ' export_report - List the usages of all exported symbols' @echo ' headers_check - Sanity check on exported headers' @echo ' headerdep - Detect inclusion cycles in headers' - @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help + @echo ' coccicheck - Check with Coccinelle' @echo '' @echo 'Kernel selftest:' @echo ' kselftest - Build and run kernel selftest (run as root)' diff --git a/scripts/Makefile.help b/scripts/Makefile.help deleted file mode 100644 index d03608f5db04..000000000000 --- a/scripts/Makefile.help +++ /dev/null @@ -1,3 +0,0 @@ - -checker-help: - @echo ' coccicheck - Check with Coccinelle.' -- cgit v1.2.3