mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 16:54:20 +08:00
09bd7c75e5
One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and
their results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=zIdO
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
"One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and their
results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation"
* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
sh: decompressor: add shipped files to .gitignore
frv: .gitignore: ignore vmlinux.lds
selinux: remove unnecessary assignment to subdir-
kbuild: specify FORCE in Makefile.headersinst as .PHONY target
kbuild: remove redundant mkdir from ./Kbuild
kbuild: optimize object directory creation for incremental build
kbuild: create object directories simpler and faster
kbuild: filter-out PHONY targets from "targets"
kbuild: remove redundant $(wildcard ...) for cmd_files calculation
kbuild: create directory for make cache only when necessary
sh: select KBUILD_DEFCONFIG depending on ARCH
kbuild: fix linker feature test macros when cross compiling with Clang
kbuild: shrink .cache.mk when it exceeds 1000 lines
kbuild: do not call cc-option before KBUILD_CFLAGS initialization
kbuild: Cache a few more calls to the compiler
kbuild: Add a cache for generated variables
kbuild: add forward declaration of default target to Makefile.asm-generic
kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
...
165 lines
6.2 KiB
Makefile
165 lines
6.2 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
# ==========================================================================
|
|
# Building binaries on the host system
|
|
# Binaries are used during the compilation of the kernel, for example
|
|
# to preprocess a data file.
|
|
#
|
|
# Both C and C++ are supported, but preferred language is C for such utilities.
|
|
#
|
|
# Sample syntax (see Documentation/kbuild/makefiles.txt for reference)
|
|
# hostprogs-y := bin2hex
|
|
# Will compile bin2hex.c and create an executable named bin2hex
|
|
#
|
|
# hostprogs-y := lxdialog
|
|
# lxdialog-objs := checklist.o lxdialog.o
|
|
# Will compile lxdialog.c and checklist.c, and then link the executable
|
|
# lxdialog, based on checklist.o and lxdialog.o
|
|
#
|
|
# hostprogs-y := qconf
|
|
# qconf-cxxobjs := qconf.o
|
|
# qconf-objs := menu.o
|
|
# Will compile qconf as a C++ program, and menu as a C program.
|
|
# They are linked as C++ code to the executable qconf
|
|
|
|
__hostprogs := $(sort $(hostprogs-y) $(hostprogs-m))
|
|
host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m))
|
|
host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m))
|
|
|
|
# C code
|
|
# Executables compiled from a single .c file
|
|
host-csingle := $(foreach m,$(__hostprogs), \
|
|
$(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
|
|
|
|
# C executables linked based on several .o files
|
|
host-cmulti := $(foreach m,$(__hostprogs),\
|
|
$(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
|
|
|
|
# Object (.o) files compiled from .c files
|
|
host-cobjs := $(sort $(foreach m,$(__hostprogs),$($(m)-objs)))
|
|
|
|
# C++ code
|
|
# C++ executables compiled from at least one .cc file
|
|
# and zero or more .c files
|
|
host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m)))
|
|
|
|
# C++ Object (.o) files compiled from .cc files
|
|
host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
|
|
|
|
# Object (.o) files used by the shared libaries
|
|
host-cshobjs := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
|
|
host-cxxshobjs := $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs))))
|
|
|
|
host-csingle := $(addprefix $(obj)/,$(host-csingle))
|
|
host-cmulti := $(addprefix $(obj)/,$(host-cmulti))
|
|
host-cobjs := $(addprefix $(obj)/,$(host-cobjs))
|
|
host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti))
|
|
host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs))
|
|
host-cshlib := $(addprefix $(obj)/,$(host-cshlib))
|
|
host-cxxshlib := $(addprefix $(obj)/,$(host-cxxshlib))
|
|
host-cshobjs := $(addprefix $(obj)/,$(host-cshobjs))
|
|
host-cxxshobjs := $(addprefix $(obj)/,$(host-cxxshobjs))
|
|
|
|
#####
|
|
# Handle options to gcc. Support building with separate output directory
|
|
|
|
_hostc_flags = $(HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
|
|
$(HOSTCFLAGS_$(basetarget).o)
|
|
_hostcxx_flags = $(HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
|
|
$(HOSTCXXFLAGS_$(basetarget).o)
|
|
|
|
ifeq ($(KBUILD_SRC),)
|
|
__hostc_flags = $(_hostc_flags)
|
|
__hostcxx_flags = $(_hostcxx_flags)
|
|
else
|
|
__hostc_flags = -I$(obj) $(call flags,_hostc_flags)
|
|
__hostcxx_flags = -I$(obj) $(call flags,_hostcxx_flags)
|
|
endif
|
|
|
|
hostc_flags = -Wp,-MD,$(depfile) $(__hostc_flags)
|
|
hostcxx_flags = -Wp,-MD,$(depfile) $(__hostcxx_flags)
|
|
|
|
#####
|
|
# Compile programs on the host
|
|
|
|
# Create executable from a single .c file
|
|
# host-csingle -> Executable
|
|
quiet_cmd_host-csingle = HOSTCC $@
|
|
cmd_host-csingle = $(HOSTCC) $(hostc_flags) -o $@ $< \
|
|
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
|
|
$(host-csingle): $(obj)/%: $(src)/%.c FORCE
|
|
$(call if_changed_dep,host-csingle)
|
|
|
|
# Link an executable based on list of .o files, all plain c
|
|
# host-cmulti -> executable
|
|
quiet_cmd_host-cmulti = HOSTLD $@
|
|
cmd_host-cmulti = $(HOSTCC) $(HOSTLDFLAGS) -o $@ \
|
|
$(addprefix $(obj)/,$($(@F)-objs)) \
|
|
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
|
|
$(host-cmulti): FORCE
|
|
$(call if_changed,host-cmulti)
|
|
$(call multi_depend, $(host-cmulti), , -objs)
|
|
|
|
# Create .o file from a single .c file
|
|
# host-cobjs -> .o
|
|
quiet_cmd_host-cobjs = HOSTCC $@
|
|
cmd_host-cobjs = $(HOSTCC) $(hostc_flags) -c -o $@ $<
|
|
$(host-cobjs): $(obj)/%.o: $(src)/%.c FORCE
|
|
$(call if_changed_dep,host-cobjs)
|
|
|
|
# Link an executable based on list of .o files, a mixture of .c and .cc
|
|
# host-cxxmulti -> executable
|
|
quiet_cmd_host-cxxmulti = HOSTLD $@
|
|
cmd_host-cxxmulti = $(HOSTCXX) $(HOSTLDFLAGS) -o $@ \
|
|
$(foreach o,objs cxxobjs,\
|
|
$(addprefix $(obj)/,$($(@F)-$(o)))) \
|
|
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
|
|
$(host-cxxmulti): FORCE
|
|
$(call if_changed,host-cxxmulti)
|
|
$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs)
|
|
|
|
# Create .o file from a single .cc (C++) file
|
|
quiet_cmd_host-cxxobjs = HOSTCXX $@
|
|
cmd_host-cxxobjs = $(HOSTCXX) $(hostcxx_flags) -c -o $@ $<
|
|
$(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
|
|
$(call if_changed_dep,host-cxxobjs)
|
|
|
|
# Compile .c file, create position independent .o file
|
|
# host-cshobjs -> .o
|
|
quiet_cmd_host-cshobjs = HOSTCC -fPIC $@
|
|
cmd_host-cshobjs = $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $<
|
|
$(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE
|
|
$(call if_changed_dep,host-cshobjs)
|
|
|
|
# Compile .c file, create position independent .o file
|
|
# Note that plugin capable gcc versions can be either C or C++ based
|
|
# therefore plugin source files have to be compilable in both C and C++ mode.
|
|
# This is why a C++ compiler is invoked on a .c file.
|
|
# host-cxxshobjs -> .o
|
|
quiet_cmd_host-cxxshobjs = HOSTCXX -fPIC $@
|
|
cmd_host-cxxshobjs = $(HOSTCXX) $(hostcxx_flags) -fPIC -c -o $@ $<
|
|
$(host-cxxshobjs): $(obj)/%.o: $(src)/%.c FORCE
|
|
$(call if_changed_dep,host-cxxshobjs)
|
|
|
|
# Link a shared library, based on position independent .o files
|
|
# *.o -> .so shared library (host-cshlib)
|
|
quiet_cmd_host-cshlib = HOSTLLD -shared $@
|
|
cmd_host-cshlib = $(HOSTCC) $(HOSTLDFLAGS) -shared -o $@ \
|
|
$(addprefix $(obj)/,$($(@F:.so=-objs))) \
|
|
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
|
|
$(host-cshlib): FORCE
|
|
$(call if_changed,host-cshlib)
|
|
$(call multi_depend, $(host-cshlib), .so, -objs)
|
|
|
|
# Link a shared library, based on position independent .o files
|
|
# *.o -> .so shared library (host-cxxshlib)
|
|
quiet_cmd_host-cxxshlib = HOSTLLD -shared $@
|
|
cmd_host-cxxshlib = $(HOSTCXX) $(HOSTLDFLAGS) -shared -o $@ \
|
|
$(addprefix $(obj)/,$($(@F:.so=-objs))) \
|
|
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
|
|
$(host-cxxshlib): FORCE
|
|
$(call if_changed,host-cxxshlib)
|
|
$(call multi_depend, $(host-cxxshlib), .so, -objs)
|
|
|
|
targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\
|
|
$(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs) $(host-cxxshlib) $(host-cxxshobjs)
|