27 Feb, 2020
2 commits
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This trailing semicolon is unneeded.
Signed-off-by: Masahiro Yamada
Acked-by: Rob Herring -
This if_change_rule is not working properly; it cannot detect any
command line change.The reason is because cmd-check in scripts/Kbuild.include compares
$(cmd_$@) and $(cmd_$1), but cmd_dtc_dt_yaml does not exist here.For if_change_rule to work properly, the stem part of cmd_* and rule_*
must match. Because this cmd_and_fixdep invokes cmd_dtc, this rule must
be named rule_dtc.Fixes: 4f0e3a57d6eb ("kbuild: Add support for DT binding schema checks")
Signed-off-by: Masahiro Yamada
Acked-by: Rob Herring
04 Feb, 2020
1 commit
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In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.This commit renames like follows:
always -> always-y
hostprogs-y -> hostprogsSo, scripts/Makefile will look like this:
always-$(CONFIG_BUILD_BIN2C) += ...
always-$(CONFIG_KALLSYMS) += ...
...
hostprogs := $(always-y) $(always-m)I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.Signed-off-by: Masahiro Yamada
07 Jan, 2020
3 commits
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When compiling, Kbuild passes KBUILD_BASENAME (basename of the object)
and KBUILD_MODNAME (basename of the module).This commit adds another one, KBUILD_MODFILE, which is the path of
the module. (or, the path of the module it would end up in if it were
compiled as a module.)The next commit will use this to generate modules.builtin without
tristate.conf.Signed-off-by: Masahiro Yamada
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Make $(squote)$(quote)...$(quote)$(squote) a helper macro.
I will reuse it in the next commit.Signed-off-by: Masahiro Yamada
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Both 'obj-y += foo/' and 'obj-m += foo/' request Kbuild to visit the
sub-directory foo/, but the difference is that only the former combines
foo/built-in.a into the built-in.a of the current directory because
everything in sub-directories visited by obj-m is supposed to be modular.So, it makes sense to create built-in.a only if that sub-directory is
reachable by the chain of obj-y. Otherwise, built-in.a will not be
linked into vmlinux anyway. For the same reason, it is pointless to
compile obj-y objects in the directory visited by obj-m.Signed-off-by: Masahiro Yamada
14 Nov, 2019
1 commit
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There are both positive and negative options about this feature.
At first, I thought it was a good idea, but actually Linus stated a
negative opinion (https://lkml.org/lkml/2019/9/29/227). I admit it
is ugly and annoying.The baseline I'd like to keep is the compile-test of uapi headers.
(Otherwise, kernel developers have no way to ensure the correctness
of the exported headers.)I will maintain a small build rule in usr/include/Makefile.
Remove the other header test functionality.Signed-off-by: Masahiro Yamada
01 Oct, 2019
1 commit
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Commit 40df759e2b9e ("kbuild: Fix build with binutils
Reviewed-by: Nick Desaulniers
Tested-by: Nick Desaulniers
06 Sep, 2019
1 commit
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KBUILD_ENABLE_EXTRA_GCC_CHECKS started as a switch to add extra warning
options for GCC, but now it is a historical misnomer since we use it
also for Clang, DTC, and even kernel-doc.Rename it to more sensible, shorter KBUILD_EXTRA_WARN.
For the backward compatibility, KBUILD_ENABLE_EXTRA_GCC_CHECKS is still
supported (but not advertised in the documentation).I also fixed up 'make help', and updated the documentation.
Signed-off-by: Masahiro Yamada
Reviewed-by: Nathan Chancellor
Reviewed-by: Nick Desaulniers
Reviewed-by: Sedat Dilek
04 Sep, 2019
2 commits
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Kbuild provides per-file compiler flag addition/removal:
CFLAGS_.o
CFLAGS_REMOVE_.o
AFLAGS_.o
AFLAGS_REMOVE_.o
CPPFLAGS_.lds
HOSTCFLAGS_.o
HOSTCXXFLAGS_.oThe is the filename of the target with its directory and
suffix stripped.This syntax comes into a trouble when two files with the same basename
appear in one Makefile, for example:obj-y += foo.o
obj-y += dir/foo.o
CFLAGS_foo.o :=Here, the applies to both foo.o and dir/foo.o
The real world problem is:
scripts/kconfig/util.c
scripts/kconfig/lxdialog/util.cBoth files are compiled into scripts/kconfig/mconf, but only the
latter should be given with the ncurses flags.It is more sensible to use the relative path to the Makefile, like this:
obj-y += foo.o
CFLAGS_foo.o :=
obj-y += dir/foo.o
CFLAGS_dir/foo.o :=At first, I attempted to replace $(basetarget) with $*. The $* variable
is replaced with the stem ('%') part in a pattern rule. This works with
most of cases, but does not for explicit rules.For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own
explicit rules, so $* will be empty, resulting in ignoring the per-file
AFLAGS.I introduced a new variable, target-stem, which can be used also from
explicit rules.Signed-off-by: Masahiro Yamada
Acked-by: Marc Zyngier -
CONFIG_SHELL falls back to sh when bash is not installed on the system,
but nobody is testing such a case since bash is usually installed.
So, shell scripts invoked by CONFIG_SHELL are only tested with bash.It makes it difficult to test whether the hashbang #!/bin/sh is real.
For example, #!/bin/sh in arch/powerpc/kernel/prom_init_check.sh is
false. (I fixed it up)Besides, some shell scripts invoked by CONFIG_SHELL use bash-extension
and #!/bin/bash is specified as the hashbang, while CONFIG_SHELL may
not always be set to bash.Probably, the right thing to do is to introduce BASH, which is bash by
default, and always set CONFIG_SHELL to sh. Replace $(CONFIG_SHELL)
with $(BASH) for bash scripts.If somebody tries to add bash-extension to a #!/bin/sh script, it will
be caught in testing because /bin/sh is a symlink to dash on some major
distributions.Signed-off-by: Masahiro Yamada
22 Aug, 2019
1 commit
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Makefile.lib is included by Makefile.modfinal as well as Makefile.build.
Move modkern_cflags to Makefile.lib in order to simplify cmd_cc_o_c
in Makefile.modfinal. Move modkern_cflags as well for consistency.Signed-off-by: Masahiro Yamada
15 Aug, 2019
1 commit
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Currently, Kbuild treats an object as multi-used when any of
$(foo-objs), $(foo-y), $(foo-m) is set. It makes more sense to
check $(foo-) as well.In the context of foo-$(CONFIG_FOO_FEATURE1), CONFIG_FOO_FEATURE1
could be unset.Signed-off-by: Masahiro Yamada
14 Aug, 2019
2 commits
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Flex and bison are used for kconfig, dtc, genksyms, all of which are
host programs. I never imagine the kernel embeds a parser or a lexer.Move the flex and bison rules to scripts/Makefile.host. This file is
included only when hostprogs-y etc. is present in the Makefile in the
directory. So, parsing these rules are skipped in most of directories.Signed-off-by: Masahiro Yamada
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We generally expect bison to create not only a C file, but also a
header, which will be included from the lexer.Currently, Kbuild generates them in separate rules. So, for instance,
when building Kconfig, you will notice bison is invoked twice:HOSTCC scripts/kconfig/conf.o
HOSTCC scripts/kconfig/confdata.o
HOSTCC scripts/kconfig/expr.o
LEX scripts/kconfig/lexer.lex.c
YACC scripts/kconfig/parser.tab.h
HOSTCC scripts/kconfig/lexer.lex.o
YACC scripts/kconfig/parser.tab.c
HOSTCC scripts/kconfig/parser.tab.o
HOSTCC scripts/kconfig/preprocess.o
HOSTCC scripts/kconfig/symbol.o
HOSTLD scripts/kconfig/confMake handles such cases nicely in pattern rules [1]. Merge the two
rules so that one invokcation of bison can generate both of them.HOSTCC scripts/kconfig/conf.o
HOSTCC scripts/kconfig/confdata.o
HOSTCC scripts/kconfig/expr.o
LEX scripts/kconfig/lexer.lex.c
YACC scripts/kconfig/parser.tab.[ch]
HOSTCC scripts/kconfig/lexer.lex.o
HOSTCC scripts/kconfig/parser.tab.o
HOSTCC scripts/kconfig/preprocess.o
HOSTCC scripts/kconfig/symbol.o
HOSTLD scripts/kconfig/conf[1] Pattern rule
GNU Make manual says:
"Pattern rules may have more than one target. Unlike normal rules,
this does not act as many different rules with the same prerequisites
and recipe. If a pattern rule has multiple targets, make knows that
the rule's recipe is responsible for making all of the targets. The
recipe is executed only once to make all the targets. When searching
for a pattern rule to match a target, the target patterns of a rule
other than the one that matches the target in need of a rule are
incidental: make worries only about giving a recipe and prerequisites
to the file presently in question. However, when this file's recipe is
run, the other targets are marked as having been updated themselves."https://www.gnu.org/software/make/manual/html_node/Pattern-Intro.html
Signed-off-by: Masahiro Yamada
27 Jul, 2019
1 commit
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This is unused since commit 9f69a496f100 ("kbuild: split out *.mod out
of {single,multi}-used-m rules").Signed-off-by: Masahiro Yamada
17 Jul, 2019
1 commit
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It will be useful to control the header-test by a tristate option.
If CONFIG_FOO is a tristate option, you can write like this:
header-test-$(CONFIG_FOO) += foo.h
Signed-off-by: Masahiro Yamada
10 Jul, 2019
2 commits
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A missing compression utility or other errors were not picked up by make
and an empty kernel image was produced. By removing the &&, errors will
no longer be ignored.Signed-off-by: Harald Seiler
Signed-off-by: Masahiro Yamada -
Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory")
deprecated KBUILD_SRCTREE.It is only used in tools/testing/selftest/ to distinguish out-of-tree
build. Replace it with a new boolean flag, building_out_of_srctree.I also replaced the conditional ($(srctree),.) because the next commit
will allow an absolute path to be used for $(srctree) even when building
in the source tree.Signed-off-by: Masahiro Yamada
09 Jul, 2019
2 commits
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In my view, most of headers can be self-contained. So, it would be
tedious to add every header to header-test-y explicitly. We usually
end up with "all headers with some exceptions".There are two types in exceptions:
[1] headers that are never compiled as standalone units
For examples, include/linux/compiler-gcc.h is not intended for
direct inclusion. We should always exclude such ones.[2] headers that are conditionally compiled as standalone units
Some headers can be compiled only for particular architectures.
For example, include/linux/arm-cci.h can be compiled only for
arm/arm64 because it requires to exist.
Clang can compile include/soc/nps/mtm.h only for arc because
it contains an arch-specific register in inline assembler.So, you can write Makefile like this:
header-test- += linux/compiler-gcc.h
header-test-$(CONFIG_ARM) += linux/arm-cci.h
header-test-$(CONFIG_ARM64) += linux/arm-cci.h
header-test-$(CONFIG_ARC) += soc/nps/mtm.hThe 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 -
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
15 Jun, 2019
1 commit
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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
22 May, 2019
1 commit
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In order to have $ref's to schema files within the kernel, we need to
pass the base path of bindings to the schema validation tools.Cc: Masahiro Yamada
Cc: Michal Marek
Cc: devicetree@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Rob Herring
18 May, 2019
1 commit
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The 'addtree' and 'flags' in scripts/Kbuild.include are so compilecated
and ugly.As I mentioned in [1], Kbuild should stop automatic prefixing of header
search path options.I fixed up (almost) all Makefiles in the kernel. Now 'addtree' and
'flags' have been removed.Kbuild still caters to add $(srctree)/$(src) and $(objtree)/$(obj)
to the header search path for O= building, but never touches extra
compiler options from ccflags-y etc.[1]: https://patchwork.kernel.org/patch/9632347/
Signed-off-by: Masahiro Yamada
02 Apr, 2019
1 commit
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KBUILD_SRC was conventionally used for some different purposes:
[1] To remember the source tree path
[2] As a flag to check if sub-make is already done
[3] As a flag to check if Kbuild runs out of treeFor [1], we do not need to remember it because the top Makefile
can compute it by $(realpath $(dir $(lastword $(MAKEFILE_LIST))))[2] has been replaced with self-commenting 'sub_make_done'.
For [3], we can distinguish in-tree/out-of-tree by comparing
$(srctree) and '.'This commit converts [3] to prepare for the KBUILD_SRC removal.
Signed-off-by: Masahiro Yamada
14 Mar, 2019
1 commit
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scripts/Makefile.build and arch/s390/boot/Makefile use the same
command (thin archiving with symbol table creation).Avoid the code duplication, and move it to scripts/Makefile.lib.
Signed-off-by: Masahiro Yamada
28 Jan, 2019
4 commits
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The commands surrounded by ( ) are executed in a subshell, but in
most cases, we do not need to spawn an extra subshell.Signed-off-by: Masahiro Yamada
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In Kbuild, if_changed and friends must have FORCE as a prerequisite.
Hence, $(filter-out FORCE,$^) or $(filter-out $(PHONY),$^) is a common
idiom to get the names of all the prerequisites except phony targets.Add real-prereqs as a shorthand.
Note:
We cannot replace $(filter %.o,$^) in cmd_link_multi-m because $^ may
include auto-generated dependencies from the .*.cmd file when a single
object module is changed into a multi object module. Refer to commit
69ea912fda74 ("kbuild: remove unneeded link_multi_deps"). I added some
comment to avoid accidental breakage.Signed-off-by: Masahiro Yamada
Acked-by: Rob Herring -
All the callers of size_append pass $(filter-out FORCE,$^).
Move $(filter-out FORCE,$^) to the definition of size_append.This makes the callers cleaner because $(call ...) is unneeded
for a macro with no argument.Signed-off-by: Masahiro Yamada
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When building an external module, $(obj) is the absolute path to it.
The header search paths from ccflags-y etc. should not be tweaked.
Signed-off-by: Masahiro Yamada
06 Jan, 2019
4 commits
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filechk_* rules often consist of multiple 'echo' lines. They must be
surrounded with { } or ( ) to work correctly. Otherwise, only the
string from the last 'echo' would be written into the target.Let's take care of that in the 'filechk' in scripts/Kbuild.include
to clean up filechk_* rules.Signed-off-by: Masahiro Yamada
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Since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special
target"), the target file is automatically deleted on failure.The boilerplate code
... || { rm -f $@; false; }
is unneeded.
Signed-off-by: Masahiro Yamada
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Commit 3a2429e1faf4 ("kbuild: change if_changed_rule for multi-line
recipe") and commit 4f0e3a57d6eb ("kbuild: Add support for DT binding
schema checks") came in via different sub-systems.This is a follow-up cleanup.
Signed-off-by: Masahiro Yamada
-
The only/last user of UIMAGE_IN/OUT was removed by commit 4722a3e6b716
("microblaze: fix multiple bugs in arch/microblaze/boot/Makefile").The input and output should always be $< and $@.
Signed-off-by: Masahiro Yamada
30 Dec, 2018
1 commit
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Pull Kbuild updates from Masahiro Yamada:
"Kbuild core:
- remove unneeded $(call cc-option,...) switches
- consolidate Clang compiler flags into CLANG_FLAGS
- announce the deprecation of SUBDIRS
- fix single target build for external module
- simplify the dependencies of 'prepare' stage targets
- allow fixdep to directly write to .*.cmd files
- simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
- change if_changed_rule to accept multi-line recipe
- move .SECONDARY special target to scripts/Kbuild.include
- remove redundant 'set -e'
- improve parallel execution for CONFIG_HEADERS_CHECK
- misc cleanupsTreewide fixes and cleanups
- set Clang flags correctly for PowerPC boot images
- fix UML build error with CONFIG_GCC_PLUGINS
- remove unneeded patterns from .gitignore files
- refactor firmware/Makefile
- remove unneeded rules for *offsets.s
- avoid unneeded regeneration of intermediate .s files
- clean up ./KbuildModpost:
- remove unused -M, -K options
- fix false positive warnings about section mismatch
- use simple devtable lookup instead of linker magic
- misc cleanupsCoccinelle:
- relax boolinit.cocci checks for overall consistency
- fix warning messages of boolinit.cocciOther tools:
- improve -dirty check of scripts/setlocalversion
- add a tool to generate compile_commands.json from .*.cmd files"* tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (51 commits)
kbuild: remove unused cmd_gentimeconst
kbuild: remove $(obj)/ prefixes in ./Kbuild
treewide: add intermediate .s files to targets
treewide: remove explicit rules for *offsets.s
firmware: refactor firmware/Makefile
firmware: remove unnecessary patterns from .gitignore
scripts: remove unnecessary ihex2fw and check-lc_ctypes from .gitignore
um: remove unused filechk_gen_header in Makefile
scripts: add a tool to produce a compile_commands.json file
kbuild: add -Werror=implicit-int flag unconditionally
kbuild: add -Werror=strict-prototypes flag unconditionally
kbuild: add -fno-PIE flag unconditionally
scripts: coccinelle: Correct warning message
scripts: coccinelle: only suggest true/false in files that already use them
kbuild: handle part-of-module correctly for *.ll and *.symtypes
kbuild: refactor part-of-module
kbuild: refactor quiet_modtag
kbuild: remove redundant quiet_modtag for $(obj-m)
kbuild: refactor Makefile.asm-generic
user/Makefile: Fix typo and capitalization in comment section
...
14 Dec, 2018
1 commit
13 Dec, 2018
1 commit
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This adds the build infrastructure for checking DT binding schema
documents and validating dts files using the binding schema.Check DT binding schema documents:
make dt_binding_checkBuild dts files and check using DT binding schema:
make dtbs_checkOptionally, DT_SCHEMA_FILES can be passed in with a schema file(s) to
use for validation. This makes it easier to find and fix errors
generated by a specific schema.Currently, the validation targets are separate from a normal build to
avoid a hard dependency on the external DT schema project and because
there are lots of warnings generated.Cc: Jonathan Corbet
Cc: Mark Rutland
Acked-by: Masahiro Yamada
Cc: Michal Marek
Cc: linux-doc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Rob Herring
01 Dec, 2018
1 commit
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The filechk macro in scripts/Kbuild.include already sets 'set -e'.
Signed-off-by: Masahiro Yamada
30 Nov, 2018
2 commits
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All the 'graph_port' warnings have been fixed or have pending fixes, so
we can enable it by default now.Signed-off-by: Rob Herring
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The updated version of dtc has a bug fix for simple_bus_reg warnings
and lots of warnings are generated now. So disable this warning by
default.Signed-off-by: Rob Herring