From e846f0dc57f441e5e93194d39bc9b8ac2ab5e0a4 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 4 Jun 2019 15:42:48 +0300 Subject: kbuild: add support for ensuring headers are self-contained Sometimes it's useful to be able to explicitly ensure certain headers remain self-contained, i.e. that they are compilable as standalone units, by including and/or forward declaring everything they depend on. Add special target header-test-y where individual Makefiles can add headers to be tested if CONFIG_HEADER_TEST is enabled. This will generate a dummy C file per header that gets built as part of extra-y. Signed-off-by: Jani Nikula Reviewed-by: Sam Ravnborg Signed-off-by: Masahiro Yamada --- scripts/Makefile.lib | 3 +++ 1 file changed, 3 insertions(+) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f1f38c8cdc74..3e630fcaffd1 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -66,6 +66,9 @@ extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y)) extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-)) endif +# Test self-contained headers +extra-$(CONFIG_HEADER_TEST) += $(patsubst %.h,%.hdrtest.o,$(header-test-y)) + # Add subdir path extra-y := $(addprefix $(obj)/,$(extra-y)) -- cgit v1.2.3 From c93a0368aaa2962e6c89da20f79b8789b42e3387 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 1 Jul 2019 09:58:41 +0900 Subject: kbuild: do not create wrappers for header-test-y header-test-y does not work with headers in sub-directories. For example, you may want to write a Makefile, like this: include/linux/Kbuild: header-test-y += mtd/nand.h This entry will create a wrapper include/linux/mtd/nand.hdrtest.c with the following content: #include "mtd/nand.h" To make this work, we need to add $(srctree)/include/linux to the header search path. It would be tedious to add ccflags-y. Instead, we could change the *.hdrtest.c rule to wrap: #include "nand.h" This works for in-tree build since #include "..." searches in the relative path from the header with this directive. For O=... build, we need to add $(srctree)/include/linux/mtd to the header search path, which will be even more tedious. After all, I thought it would be handier to compile headers directly without creating wrappers. I added a new build rule to compile %.h into %.h.s The target is %.h.s instead of %.h.o because it is slightly faster. Also, as for GCC, an empty assembly is smaller than an empty object. I wrote the build rule: $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $< instead of: $(CC) $(c_flags) -S -o $@ -x c $< Both work fine with GCC, but the latter is bad for Clang. This comes down to the difference in the -Wunused-function policy. GCC does not warn about unused 'static inline' functions at all. Clang does not warn about the ones in included headers, but does about the ones in the source. So, we should handle headers as headers, not as source files. In fact, this has been hidden since commit abb2ea7dfd82 ("compiler, clang: suppress warning for unused static inline functions"), but we should not rely on that. Signed-off-by: Masahiro Yamada Acked-by: Jani Nikula Tested-by: Jani Nikula --- .gitignore | 1 - Documentation/dontdiff | 1 - Documentation/kbuild/makefiles.txt | 3 +-- Makefile | 1 - scripts/Makefile.build | 10 +++++----- scripts/Makefile.lib | 2 +- scripts/package/mkspec | 2 +- 7 files changed, 8 insertions(+), 12 deletions(-) (limited to 'scripts/Makefile.lib') diff --git a/.gitignore b/.gitignore index 4bb60f0fa23b..7587ef56b92d 100644 --- a/.gitignore +++ b/.gitignore @@ -22,7 +22,6 @@ *.elf *.gcno *.gz -*.hdrtest.c *.i *.ko *.lex.c diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 554dfe4883d2..5eba889ea84d 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -19,7 +19,6 @@ *.grep *.grp *.gz -*.hdrtest.c *.html *.i *.jpeg diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index ca4b24ec0399..5080fec34609 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -1023,8 +1023,7 @@ When kbuild executes, the following steps are followed (roughly): header-test-y specifies headers (*.h) in the current directory that should be compile tested to ensure they are self-contained, i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled, - this autogenerates dummy sources to include the headers, and builds them - as part of extra-y. + this builds them as part of extra-y. --- 6.7 Commands useful for building a boot image diff --git a/Makefile b/Makefile index fca827bc3f77..82fccd37a1ad 100644 --- a/Makefile +++ b/Makefile @@ -1663,7 +1663,6 @@ clean: $(clean-dirs) -o -name '*.dwo' -o -name '*.lst' \ -o -name '*.su' \ -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ - -o -name '*.hdrtest.c' \ -o -name '*.lex.c' -o -name '*.tab.[ch]' \ -o -name '*.asn1.[ch]' \ -o -name '*.symtypes' -o -name 'modules.order' \ diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ee0319560513..776842b7e6a3 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -294,14 +294,14 @@ quiet_cmd_cc_lst_c = MKLST $@ $(obj)/%.lst: $(src)/%.c FORCE $(call if_changed_dep,cc_lst_c) -# Dummy C sources for header test (header-test-y target) +# header test (header-test-y target) # --------------------------------------------------------------------------- -quiet_cmd_header_test = HDRTEST $@ - cmd_header_test = echo "\#include \"$*.h\"" > $@ +quiet_cmd_cc_s_h = CC $@ + cmd_cc_s_h = $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $< -$(obj)/%.hdrtest.c: - $(call cmd,header_test) +$(obj)/%.h.s: $(src)/%.h FORCE + $(call if_changed_dep,cc_s_h) # Compile assembler sources (.S) # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 3e630fcaffd1..55ae1ec65342 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -67,7 +67,7 @@ extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-)) endif # Test self-contained headers -extra-$(CONFIG_HEADER_TEST) += $(patsubst %.h,%.hdrtest.o,$(header-test-y)) +extra-$(CONFIG_HEADER_TEST) += $(addsuffix .s, $(header-test-y)) # Add subdir path diff --git a/scripts/package/mkspec b/scripts/package/mkspec index 009147d4718e..2d29df4a0a53 100755 --- a/scripts/package/mkspec +++ b/scripts/package/mkspec @@ -31,7 +31,7 @@ PROVIDES="$PROVIDES kernel-$KERNELRELEASE" __KERNELRELEASE=$(echo $KERNELRELEASE | sed -e "s/-/_/g") EXCLUDES="$RCS_TAR_IGNORE --exclude=.tmp_versions --exclude=*vmlinux* \ --exclude=*.o --exclude=*.ko --exclude=*.cmd --exclude=Documentation \ ---exclude=.config.old --exclude=.missing-syscalls.d" +--exclude=.config.old --exclude=.missing-syscalls.d --exclude=*.s" # We can label the here-doc lines for conditional output to the spec file # -- cgit v1.2.3 From 1e21cbfada87f697a2a7c450542a7d28925abee6 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 1 Jul 2019 09:58:42 +0900 Subject: kbuild: support header-test-pattern-y In my view, most of headers can be self-contained. So, it would be tedious to add every header to header-test-y explicitly. We usually end up with "all headers with some exceptions". There are two types in exceptions: [1] headers that are never compiled as standalone units For examples, include/linux/compiler-gcc.h is not intended for direct inclusion. We should always exclude such ones. [2] headers that are conditionally compiled as standalone units Some headers can be compiled only for particular architectures. For example, include/linux/arm-cci.h can be compiled only for arm/arm64 because it requires to exist. Clang can compile include/soc/nps/mtm.h only for arc because it contains an arch-specific register in inline assembler. So, you can write Makefile like this: header-test- += linux/compiler-gcc.h header-test-$(CONFIG_ARM) += linux/arm-cci.h header-test-$(CONFIG_ARM64) += linux/arm-cci.h header-test-$(CONFIG_ARC) += soc/nps/mtm.h The new syntax header-test-pattern-y will be useful to specify "the rest". The typical usage is like this: header-test-pattern-y += */*.h This will add all the headers in sub-directories to the test coverage, excluding $(header-test-). In this regards, header-test-pattern-y behaves like a weaker variant of header-test-y. Caveat: The patterns in header-test-pattern-y are prefixed with $(srctree)/$(src)/ but not $(objtree)/$(obj)/. Stale generated headers are often left over when you traverse the git history without cleaning. Wildcard patterns for $(objtree) may match to stale headers, which could fail to compile. One pitfall is $(srctree)/$(src)/ and $(objtree)/$(obj)/ point to the same directory for in-tree building. So, header-test-pattern-y should be used with care since it can potentially match to stale headers. Caveat2: You could use wildcard for header-test-. For example, header-test- += asm-generic/% ... will exclude headers in asm-generic directory. Unfortunately, the wildcard character is '%' instead of '*' here because this is evaluated by $(filter-out ...) whereas header-test-pattern-y is evaluated by $(wildcard ...). This is a kludge, but seems useful in some places... Signed-off-by: Masahiro Yamada Tested-by: Jani Nikula --- Documentation/kbuild/makefiles.txt | 10 ++++++++++ scripts/Makefile.lib | 11 +++++++++++ 2 files changed, 21 insertions(+) (limited to 'scripts/Makefile.lib') diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 5080fec34609..b817e6cefb77 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -1025,6 +1025,16 @@ When kbuild executes, the following steps are followed (roughly): i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled, this builds them as part of extra-y. + header-test-pattern-y + + This works as a weaker version of header-test-y, and accepts wildcard + patterns. The typical usage is: + + header-test-pattern-y += *.h + + This specifies all the files that matches to '*.h' in the current + directory, but the files in 'header-test-' are excluded. + --- 6.7 Commands useful for building a boot image Kbuild provides a few macros that are useful when building a diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 55ae1ec65342..281864fcf0fe 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -67,6 +67,17 @@ extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-)) endif # Test self-contained headers + +# Wildcard searches in $(srctree)/$(src)/, but not in $(objtree)/$(obj)/. +# Stale generated headers are often left over, so pattern matching should +# be avoided. Please notice $(srctree)/$(src)/ and $(objtree)/$(obj) point +# to the same location for in-tree building. So, header-test-pattern-y should +# be used with care. +header-test-y += $(filter-out $(header-test-), \ + $(patsubst $(srctree)/$(src)/%, %, \ + $(wildcard $(addprefix $(srctree)/$(src)/, \ + $(header-test-pattern-y))))) + extra-$(CONFIG_HEADER_TEST) += $(addsuffix .s, $(header-test-y)) # Add subdir path -- cgit v1.2.3 From 051f278e9d81bed253bf89c66c80b8b921aafa8a Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 6 Jul 2019 12:07:12 +0900 Subject: kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory") deprecated KBUILD_SRCTREE. It is only used in tools/testing/selftest/ to distinguish out-of-tree build. Replace it with a new boolean flag, building_out_of_srctree. I also replaced the conditional ($(srctree),.) because the next commit will allow an absolute path to be used for $(srctree) even when building in the source tree. Signed-off-by: Masahiro Yamada --- Makefile | 19 ++++++++----------- scripts/Makefile.build | 2 +- scripts/Makefile.host | 2 +- scripts/Makefile.lib | 2 +- scripts/Makefile.modbuiltin | 2 +- scripts/gdb/linux/Makefile | 2 +- tools/testing/selftests/Makefile | 2 +- tools/testing/selftests/lib.mk | 4 ++-- 8 files changed, 16 insertions(+), 19 deletions(-) (limited to 'scripts/Makefile.lib') diff --git a/Makefile b/Makefile index 99336b60f1a4..91ad737ff538 100644 --- a/Makefile +++ b/Makefile @@ -228,9 +228,12 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif +export KBUILD_CHECKSRC KBUILD_EXTMOD + ifeq ($(abs_srctree),$(abs_objtree)) # building in the source tree srctree := . + building_out_of_srctree := else ifeq ($(abs_srctree)/,$(dir $(abs_objtree))) # building in a subdirectory of the source tree @@ -238,19 +241,13 @@ else else srctree := $(abs_srctree) endif - - # TODO: - # KBUILD_SRC is only used to distinguish in-tree/out-of-tree build. - # Replace it with $(srctree) or something. - KBUILD_SRC := $(abs_srctree) + building_out_of_srctree := 1 endif -export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC - objtree := . VPATH := $(srctree) -export srctree objtree VPATH +export building_out_of_srctree srctree objtree VPATH # To make sure we do not include .config for any of the *config targets # catch them early, and hand them over to scripts/kconfig/Makefile @@ -453,7 +450,7 @@ USERINCLUDE := \ LINUXINCLUDE := \ -I$(srctree)/arch/$(SRCARCH)/include \ -I$(objtree)/arch/$(SRCARCH)/include/generated \ - $(if $(filter .,$(srctree)),,-I$(srctree)/include) \ + $(if $(building_out_of_srctree),-I$(srctree)/include) \ -I$(objtree)/include \ $(USERINCLUDE) @@ -514,7 +511,7 @@ PHONY += outputmakefile # At the same time when output Makefile generated, generate .gitignore to # ignore whole output directory outputmakefile: -ifneq ($(srctree),.) +ifdef building_out_of_srctree $(Q)ln -fsn $(srctree) source $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree) $(Q)test -e .gitignore || \ @@ -1101,7 +1098,7 @@ PHONY += prepare archprepare prepare1 prepare3 # and if so do: # 1) Check that make has not been executed in the kernel src $(srctree) prepare3: include/config/kernel.release -ifneq ($(srctree),.) +ifdef building_out_of_srctree @$(kecho) ' Using $(srctree) as source for kernel' $(Q)if [ -f $(srctree)/.config -o \ -d $(srctree)/include/config -o \ diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 776842b7e6a3..be38198d98b2 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -513,7 +513,7 @@ existing-targets := $(wildcard $(sort $(targets))) -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) -ifneq ($(srctree),.) +ifdef building_out_of_srctree # Create directories for object files if they do not exist obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets)))) # If targets exist, their directories apparently exist. Skip mkdir. diff --git a/scripts/Makefile.host b/scripts/Makefile.host index b6a54bdf0965..fcf0213e6ac8 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -69,7 +69,7 @@ _hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \ # $(objtree)/$(obj) for including generated headers from checkin source files ifeq ($(KBUILD_EXTMOD),) -ifneq ($(srctree),.) +ifdef building_out_of_srctree _hostc_flags += -I $(objtree)/$(obj) _hostcxx_flags += -I $(objtree)/$(obj) endif diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 281864fcf0fe..8f2eb799a9b2 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -154,7 +154,7 @@ endif # $(srctree)/$(src) for including checkin headers from generated source files # $(objtree)/$(obj) for including generated headers from checkin source files ifeq ($(KBUILD_EXTMOD),) -ifneq ($(srctree),.) +ifdef building_out_of_srctree _c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) _a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) _cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin index ea90a90b41a0..50a9990760f3 100644 --- a/scripts/Makefile.modbuiltin +++ b/scripts/Makefile.modbuiltin @@ -15,7 +15,7 @@ include include/config/tristate.conf include scripts/Kbuild.include -ifneq ($(srctree),.) +ifdef building_out_of_srctree # Create output directory if not already present _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) endif diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile index 9fd3d8ed731a..124755087510 100644 --- a/scripts/gdb/linux/Makefile +++ b/scripts/gdb/linux/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -ifneq ($(srctree),.) +ifdef building_out_of_srctree symlinks := $(patsubst $(srctree)/$(src)/%,%,$(wildcard $(srctree)/$(src)/*.py)) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 9781ca79794a..25b43a8c2b15 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -74,7 +74,7 @@ endif # Append kselftest to KBUILD_OUTPUT to avoid cluttering # KBUILD_OUTPUT with selftest objects and headers installed # by selftests Makefile or lib.mk. -ifneq ($(KBUILD_SRC),) +ifdef building_out_of_srctree override LDFLAGS = endif diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index 077337195783..1c8a1963d03f 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -70,7 +70,7 @@ define RUN_TESTS endef run_tests: all -ifneq ($(KBUILD_SRC),) +ifdef building_out_of_srctree @if [ "X$(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES)" != "X" ]; then @rsync -aq $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(OUTPUT) fi @@ -125,7 +125,7 @@ clean: # When make O= with kselftest target from main level # the following aren't defined. # -ifneq ($(KBUILD_SRC),) +ifdef building_out_of_srctree LINK.c = $(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH) COMPILE.S = $(CC) $(ASFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c LINK.S = $(CC) $(ASFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH) -- cgit v1.2.3 From b956c7a6df3aa01f357f8ac5bc3e44bc3ab7befb Mon Sep 17 00:00:00 2001 From: Harald Seiler Date: Tue, 9 Jul 2019 12:50:50 +0200 Subject: kbuild: fix compression errors getting ignored A missing compression utility or other errors were not picked up by make and an empty kernel image was produced. By removing the &&, errors will no longer be ignored. Signed-off-by: Harald Seiler Signed-off-by: Masahiro Yamada --- scripts/Makefile.lib | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 8f2eb799a9b2..6cb3aa5cbc79 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -345,19 +345,19 @@ printf "%08x\n" $$dec_size | \ ) quiet_cmd_bzip2 = BZIP2 $@ - cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9 && $(size_append); } > $@ + cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9; $(size_append); } > $@ # Lzma # --------------------------------------------------------------------------- quiet_cmd_lzma = LZMA $@ - cmd_lzma = { cat $(real-prereqs) | lzma -9 && $(size_append); } > $@ + cmd_lzma = { cat $(real-prereqs) | lzma -9; $(size_append); } > $@ quiet_cmd_lzo = LZO $@ - cmd_lzo = { cat $(real-prereqs) | lzop -9 && $(size_append); } > $@ + cmd_lzo = { cat $(real-prereqs) | lzop -9; $(size_append); } > $@ quiet_cmd_lz4 = LZ4 $@ - cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout && \ + cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout; \ $(size_append); } > $@ # U-Boot mkimage @@ -400,7 +400,7 @@ quiet_cmd_uimage = UIMAGE $@ # big dictionary would increase the memory usage too much in the multi-call # decompression mode. A BCJ filter isn't used either. quiet_cmd_xzkern = XZKERN $@ - cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh && \ + cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \ $(size_append); } > $@ quiet_cmd_xzmisc = XZMISC $@ -- cgit v1.2.3