summaryrefslogtreecommitdiffstats
path: root/scripts/Kbuild.include (follow)
Commit message (Collapse)AuthorAgeFilesLines
* kbuild: replace $(dot-target).tmp in filechk with $(tmp-target)Masahiro Yamada2023-01-221-4/+4
| | | | | | | $(tmp-target) is a better fit for local use like this. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: add more comments for KBUILD_NOCMDDEP=1Masahiro Yamada2023-01-221-0/+6
| | | | | | | | | | | | | | The cmd-check for KBUILD_NOCMDDEP=1 may not be clear until you see commit c4d5ee13984f ("kbuild: make KBUILD_NOCMDDEP=1 handle empty built-in.o"). When a phony target (i.e. FORCE) is the only prerequisite, Kbuild uses a tricky way to detect that the target does not exist. Add more comments. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: rename cmd_$@ to savedcmd_$@ in *.cmd filesMasahiro Yamada2023-01-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | The cmd-check macro compares $(cmd_$@) and $(cmd_$1), but a pitfall is that you cannot use cmd_<target> as the variable name for the command. For example, the following code will not work in the top Makefile or ./Kbuild. quiet_cmd_foo = GEN $@ cmd_foo = touch $@ targets += foo foo: FORCE $(call if_changed,foo) In this case, both $@ and $1 are expanded to 'foo', so $(cmd_check) is always empty. We do not need to use the same prefix for cmd_$@ and cmd_$1. Rename the former to savedcmd_$@. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: allow to combine multiple V= levelsMasahiro Yamada2023-01-221-2/+2
| | | | | | | | | | | | | | | | | | Commit a6de553da01c ("kbuild: Allow to combine multiple W= levels") supported W=123 to enable all the extra warning groups. I think a similar idea is applicable to the V= option. V=1 echos the whole command V=2 prints the reason for rebuilding These are orthogonal, and can be enabled at the same time. This commit supports V=12 to enable both of them. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: print short log in addition to the whole command with V=1Masahiro Yamada2023-01-221-13/+13
| | | | | | | | | | | | | | | | | | | | | | "make V=1" prints the whole command instead of the short log, but I think it is nicer to print both so that you can easily spot the build rule of your interest. This commit changes V=1 to print the short log (the line starts with '#'), followed by the full log. In parallel builds, the short/full logs from the same build rule may be interspersed. If you want to avoid it, please add -Otarget option. Kbuild will never set it by default because Make would buffer the logs and lose the escape sequences. (Modern compilers print warnings and errors in color, but only when they write to a terminal.) This is also a preparation for supporting V=12 because V=2 appends the reason for rebuilding to the short log. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: use .NOTINTERMEDIATE for future GNU Make versionsMasahiro Yamada2022-12-131-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In Kbuild, some files are generated by chains of pattern/implicit rules. For example, *.dtb.o files in drivers/of/unittest-data/Makefile are generated by the chain of 3 pattern rules, like this: %.dts -> %.dtb -> %.dtb.S -> %.dtb.o Here, %.dts is the real source, %.dtb.o is the final target. %.dtb and %.dtb.S are called "intermediate files". As GNU Make manual [1] says, intermediate files are treated differently in two ways: (a) The first difference is what happens if the intermediate file does not exist. If an ordinary file 'b' does not exist, and make considers a target that depends on 'b', it invariably creates 'b' and then updates the target from 'b'. But if 'b' is an intermediate file, then make can leave well enough alone: it won't create 'b' unless one of its prerequisites is out of date. This means the target depending on 'b' won't be rebuilt either, unless there is some other reason to update that target: for example the target doesn't exist or a different prerequisite is newer than the target. (b) The second difference is that if make does create 'b' in order to update something else, it deletes 'b' later on after it is no longer needed. Therefore, an intermediate file which did not exist before make also does not exist after make. make reports the deletion to you by printing a 'rm' command showing which file it is deleting. The combination of these is problematic for Kbuild because most of the build rules depend on FORCE and the if_changed* macros really determine if the target should be updated. So, all missing files, whether they are intermediate or not, are always rebuilt. To see the problem, delete ".SECONDARY:" from scripts/Kbuild.include, and repeat this command: $ make allmodconfig drivers/of/unittest-data/ The intermediate files will be deleted, which results in rebuilding intermediate and final objects in the next run of make. In the old days, people suppressed (b) in inconsistent ways. As commit 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers") noted, you should not use .PRECIOUS because .PRECIOUS has the following behavior (c), which is not likely what you want. (c) If make is killed or interrupted during the execution of their recipes, the target is not deleted. Also, the target is not deleted on error even if .DELETE_ON_ERROR is specified. .SECONDARY is a much better way to disable (b), but a small problem is that .SECONDARY enables (a), which gives a side-effect to $?; prerequisites marked as .SECONDARY do not appear in $?. This is a drawback for Kbuild. I thought it was a bug and opened a bug report. As Paul, the GNU Make maintainer, concluded in [2], this is not a bug. A good news is that, GNU Make 4.4 added the perfect solution, .NOTINTERMEDIATE, which cancels both (a) and (b). For clarificaton, my understanding of .INTERMEDIATE, .SECONDARY, .PRECIOUS and .NOTINTERMEDIATE are as follows: (a) (b) (c) .INTERMEDIATE enable enable disable .SECONDARY enable disable disable .PRECIOUS disable disable enable .NOTINTERMEDIATE disable disable disable However, GNU Make 4.4 has a bug for the global .NOTINTERMEDIATE. [3] It was fixed by commit 6164608900ad ("[SV 63417] Ensure global .NOTINTERMEDIATE disables all intermediates"), and will be available in the next release of GNU Make. The following is the gain for .NOTINTERMEDIATE: [Current Make] $ make allnoconfig vmlinux [ full build ] $ rm include/linux/device.h $ make vmlinux CALL scripts/checksyscalls.sh Make does not notice the removal of <linux/device.h>. [Future Make] $ make-latest allnoconfig vmlinux [ full build ] $ rm include/linux/device.h $ make-latest vmlinux CC arch/x86/kernel/asm-offsets.s In file included from ./include/linux/writeback.h:13, from ./include/linux/memcontrol.h:22, from ./include/linux/swap.h:9, from ./include/linux/suspend.h:5, from arch/x86/kernel/asm-offsets.c:13: ./include/linux/blk_types.h:11:10: fatal error: linux/device.h: No such file or directory 11 | #include <linux/device.h> | ^~~~~~~~~~~~~~~~ compilation terminated. make-latest[1]: *** [scripts/Makefile.build:114: arch/x86/kernel/asm-offsets.s] Error 1 make-latest: *** [Makefile:1282: prepare0] Error 2 Make notices the removal of <linux/device.h>, and rebuilds objects that depended on <linux/device.h>. There exists a source file that includes <linux/device.h>, and it raises an error. To see detailed background information, refer to commit 2d3b1b8f0da7 ("kbuild: drop $(wildcard $^) check in if_changed* for faster rebuild"). [1]: https://www.gnu.org/software/make/manual/make.html#Chained-Rules [2]: https://savannah.gnu.org/bugs/?55532 [3]: https://savannah.gnu.org/bugs/?63417 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: add read-file macroMasahiro Yamada2022-12-131-0/+14
| | | | | | | | | | | | | Since GNU Make 4.2, $(file ...) supports the read operater '<', which is useful to read a file without forking a new process. No warning is shown even if the input file is missing. For older Make versions, it falls back to the cat command. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Tested-by: Alexander Lobakin <alexandr.lobakin@intel.com>
* kbuild: add test-{ge,gt,le,lt} macrosMasahiro Yamada2022-12-131-0/+16
| | | | | | | | | | | | | | | | | | | GNU Make 4.4 introduced $(intcmp ...), which is useful to compare two integers without forking a new process. Add test-{ge,gt,le,lt} macros, which work more efficiently with GNU Make >= 4.4. For older Make versions, they fall back to the 'test' shell command. The first two parameters to $(intcmp ...) must not be empty. To avoid the syntax error, I appended '0' to them. Fortunately, '00' is treated as '0'. This is needed because CONFIG options may expand to an empty string when the kernel configuration is not included. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: add kbuild-file macroMasahiro Yamada2022-11-221-0/+5
| | | | | | | | | | | | While building, installing, cleaning, Kbuild visits sub-directories and includes 'Kbuild' or 'Makefile' that exists there. Add 'kbuild-file' macro, and reuse it from scripts/Makefie.* Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Alexander Lobakin <alobakin@pm.me> Tested-by: Alexander Lobakin <alobakin@pm.me>
* kbuild: remove the target in signal traps when interruptedMasahiro Yamada2022-09-281-1/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When receiving some signal, GNU Make automatically deletes the target if it has already been changed by the interrupted recipe. If the target is possibly incomplete due to interruption, it must be deleted so that it will be remade from scratch on the next run of make. Otherwise, the target would remain corrupted permanently because its timestamp had already been updated. Thanks to this behavior of Make, you can stop the build any time by pressing Ctrl-C, and just run 'make' to resume it. Kbuild also relies on this feature, but it is equivalently important for any build systems that make decisions based on timestamps (if you want to support Ctrl-C reliably). However, this does not always work as claimed; Make immediately dies with Ctrl-C if its stderr goes into a pipe. [Test Makefile] foo: echo hello > $@ sleep 3 echo world >> $@ [Test Result] $ make # hit Ctrl-C echo hello > foo sleep 3 ^Cmake: *** Deleting file 'foo' make: *** [Makefile:3: foo] Interrupt $ make 2>&1 | cat # hit Ctrl-C echo hello > foo sleep 3 ^C$ # 'foo' is often left-over The reason is because SIGINT is sent to the entire process group. In this example, SIGINT kills 'cat', and 'make' writes the message to the closed pipe, then dies with SIGPIPE before cleaning the target. A typical bad scenario (as reported by [1], [2]) is to save build log by using the 'tee' command: $ make 2>&1 | tee log This can be problematic for any build systems based on Make, so I hope it will be fixed in GNU Make. The maintainer of GNU Make stated this is a long-standing issue and difficult to fix [3]. It has not been fixed yet as of writing. So, we cannot rely on Make cleaning the target. We can do it by ourselves, in signal traps. As far as I understand, Make takes care of SIGHUP, SIGINT, SIGQUIT, and SITERM for the target removal. I added the traps for them, and also for SIGPIPE just in case cmd_* rule prints something to stdout or stderr (but I did not observe an actual case where SIGPIPE was triggered). [Note 1] The trap handler might be worth explaining. rm -f $@; trap - $(sig); kill -s $(sig) $$ This lets the shell kill itself by the signal it caught, so the parent process can tell the child has exited on the signal. Generally, this is a proper manner for handling signals, in case the calling program (like Bash) may monitor WIFSIGNALED() and WTERMSIG() for WCE although this may not be a big deal here because GNU Make handles SIGHUP, SIGINT, SIGQUIT in WUE and SIGTERM in IUE. IUE - Immediate Unconditional Exit WUE - Wait and Unconditional Exit WCE - Wait and Cooperative Exit For details, see "Proper handling of SIGINT/SIGQUIT" [4]. [Note 2] Reverting 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") would directly address [1], but it only saves if_changed_dep. As reported in [2], all commands that use redirection can potentially leave an empty (i.e. broken) target. [Note 3] Another (even safer) approach might be to always write to a temporary file, and rename it to $@ at the end of the recipe. <command> > $(tmp-target) mv $(tmp-target) $@ It would require a lot of Makefile changes, and result in ugly code, so I did not take it. [Note 4] A little more thoughts about a pattern rule with multiple targets (or a grouped target). %.x %.y: %.z <recipe> When interrupted, GNU Make deletes both %.x and %.y, while this solution only deletes $@. Probably, this is not a big deal. The next run of make will execute the rule again to create $@ along with the other files. [1]: https://lore.kernel.org/all/YLeot94yAaM4xbMY@gmail.com/ [2]: https://lore.kernel.org/all/20220510221333.2770571-1-robh@kernel.org/ [3]: https://lists.gnu.org/archive/html/help-make/2021-06/msg00001.html [4]: https://www.cons.org/cracauer/sigint.html Fixes: 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
* kbuild: add cmd_and_savecmd macroMasahiro Yamada2022-06-011-2/+4
| | | | | | | | | | | | | | | | | | Separate out the command execution part of if_changed, as we did for if_changed_dep. This allows us to reuse it in if_changed_rule. define rule_foo $(call cmd_and_savecmd,foo) $(call cmd,bar) endef Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
* kbuild: do not create *.prelink.o for Clang LTO or IBTMasahiro Yamada2022-05-291-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_LTO_CLANG=y, additional intermediate *.prelink.o is created for each module. Also, objtool is postponed until LLVM IR is converted to ELF. CONFIG_X86_KERNEL_IBT works in a similar way to postpone objtool until objects are merged together. This commit stops generating *.prelink.o, so the build flow will look similar with/without LTO. The following figures show how the LTO build currently works, and how this commit is changing it. Current build flow ================== [1] single-object module $(LD) $(CC) +objtool $(LD) foo.c --------------------> foo.o -----> foo.prelink.o -----> foo.ko (LLVM IR) (ELF) | (ELF) | foo.mod.o --/ (LLVM IR) [2] multi-object module $(LD) $(CC) $(AR) +objtool $(LD) foo1.c -----> foo1.o -----> foo.o -----> foo.prelink.o -----> foo.ko | (archive) (ELF) | (ELF) foo2.c -----> foo2.o --/ | (LLVM IR) foo.mod.o --/ (LLVM IR) One confusion is that foo.o in multi-object module is an archive despite of its suffix. New build flow ============== [1] single-object module Since there is only one object, there is no need to keep the LLVM IR. Use $(CC)+$(LD) to generate an ELF object in one build rule. When LTO is disabled, $(LD) is unneeded because $(CC) produces an ELF object. $(CC)+$(LD)+objtool $(LD) foo.c ----------------------------> foo.o ---------> foo.ko (ELF) | (ELF) | foo.mod.o --/ (LLVM IR) [2] multi-object module Previously, $(AR) was used to combine LLVM IR files into an archive, but there was no technical reason to do so. Use $(LD) to merge them into a single ELF object. $(LD) $(CC) +objtool $(LD) foo1.c ---------> foo1.o ---------> foo.o ---------> foo.ko | (ELF) | (ELF) foo2.c ---------> foo2.o ----/ | (LLVM IR) foo.mod.o --/ (LLVM IR) Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64) Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
* certs: simplify $(srctree)/ handling and remove config_filename macroMasahiro Yamada2022-01-081-47/+0
| | | | | | | | | | | | | | | | | | | | | | | | The complex macro, config_filename, was introduced to do: [1] drop double-quotes from the string value [2] add $(srctree)/ prefix in case the file is not found in $(objtree) [3] escape spaces and more [1] will be more generally handled by Kconfig later. As for [2], Kbuild uses VPATH to search for files in $(objtree), $(srctree) in this order. GNU Make can natively handle it. As for [3], converting $(space) to $(space_escape) back and forth looks questionable to me. It is well-known that GNU Make cannot handle file paths with spaces in the first place. Instead of using the complex macro, use $< so it will be expanded to the file path of the key. Remove config_filename, finally. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: warn if FORCE is missing for if_changed(_dep,_rule) and filechkMasahiro Yamada2021-09-031-1/+6
| | | | | | | | | | | | | | | | | | | if_changed, if_changed_dep, and if_changed_rule must have FORCE as a prerequisite so the command line change is detected. Documentation/kbuild/makefiles.rst clearly explains it: Note: It is a typical mistake to forget the FORCE prerequisite. However, not all people follow the document. This mistake occurred again and again, so a compelling force is needed. Show a warning if FORCE is missing in the prerequisite of if_changed and friends. Same for filechk. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nicolas Schier <n.schier@avm.de>
* kbuild: macrofy the condition of if_changed and friendsMasahiro Yamada2021-09-031-3/+5
| | | | | | | | | Add a new macro that expands into $(newer-prereqs)$(cmd-check). It makes it easier to add common code for if_changed, if_changed_dep, and if_changed_rule. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: sink stdout from cmd for silent buildMasahiro Yamada2021-05-261-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with 'make -s', no output to stdout should be printed. As Arnd Bergmann reported [1], mkimage shows the detailed information of the generated images. I think this should be suppressed by the 'cmd' macro instead of by individual scripts. Insert 'exec >/dev/null;' in order to redirect stdout to /dev/null for silent builds. [Note about this implementation] 'exec >/dev/null;' may look somewhat tricky, but this has a reason. Appending '>/dev/null' at the end of command line is a common way for redirection, so I first tried this: cmd = @set -e; $(echo-cmd) $(cmd_$(1)) >/dev/null ... but it would not work if $(cmd_$(1)) itself contains a redirection. For example, cmd_wrap in scripts/Makefile.asm-generic redirects the output from the 'echo' command into the target file. It would be expanded into: echo "#include <asm-generic/$*.h>" > $@ >/dev/null Then, the target file gets empty because the string will go to /dev/null instead of $@. Next, I tried this: cmd = @set -e; $(echo-cmd) { $(cmd_$(1)); } >/dev/null The form above would be expanded into: { echo "#include <asm-generic/$*.h>" > $@; } >/dev/null This works as expected. However, it would be a syntax error if $(cmd_$(1)) is empty. When CONFIG_TRIM_UNUSED_KSYMS is disabled, $(call cmd,gen_ksymdeps) in scripts/Makefile.build would be expanded into: set -e; { ; } >/dev/null ..., which causes an syntax error. I also tried this: cmd = @set -e; $(echo-cmd) ( $(cmd_$(1)) ) >/dev/null ... but this causes a syntax error for the same reason. So, finally I adopted: cmd = @set -e; $(echo-cmd) exec >/dev/null; $(cmd_$(1)) [1]: https://lore.kernel.org/lkml/20210514135752.2910387-1-arnd@kernel.org/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: split cc-option and friends to scripts/Makefile.compilerMasahiro Yamada2021-04-241-80/+0
| | | | | | | | | | | | | scripts/Kbuild.include is included everywhere, but macros such as cc-option are needed by build targets only. For example, when 'make clean' traverses the tree, it does not need to evaluate $(call cc-option,). Split cc-option, ld-option, etc. to scripts/Makefile.compiler, which is only included from the top Makefile and scripts/Makefile.build. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: remove ld-version macroMasahiro Yamada2021-02-221-5/+1
| | | | | | | | There is no direct user of ld-version; you can use CONFIG_LD_VERSION if needed. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
* kbuild: remove leftover comment for filechk utilityRasmus Villemoes2020-10-201-2/+0
| | | | | | | | | | After commit 43fee2b23895 ("kbuild: do not redirect the first prerequisite for filechk"), the rule is no longer automatically passed $< as stdin, so remove the stale comment. Fixes: 43fee2b23895 ("kbuild: do not redirect the first prerequisite for filechk") Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option baseMasahiro Yamada2020-08-091-7/+3
| | | | | | | | | | Commit d26e94149276 ("kbuild: no gcc-plugins during cc-option tests") was neeeded because scripts/Makefile.gcc-plugins was too early. This is unneeded by including scripts/Makefile.gcc-plugins last, and being careful to not add cc-option tests after it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: improve cc-option to clean up all temporary filesMasahiro Yamada2020-06-171-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | When cc-option and friends evaluate compiler flags, the temporary file $$TMP is created as an output object, and automatically cleaned up. The actual file path of $$TMP is .<pid>.tmp, here <pid> is the process ID of $(shell ...) invoked from cc-option. (Please note $$$$ is the escape sequence of $$). Such garbage files are cleaned up in most cases, but some compiler flags create additional output files. For example, -gsplit-dwarf creates a .dwo file. When CONFIG_DEBUG_INFO_SPLIT=y, you will see a bunch of .<pid>.dwo files left in the top of build directories. You may not notice them unless you do 'ls -a', but the garbage files will increase every time you run 'make'. This commit changes the temporary object path to .tmp_<pid>/tmp, and removes .tmp_<pid> directory when exiting. Separate build artifacts such as *.dwo will be cleaned up all together because their file paths are usually determined based on the base name of the object. Another example is -ftest-coverage, which outputs the coverage data into <base-name-of-object>.gcno Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: use -MMD instead of -MD to exclude system headers from dependencyMasahiro Yamada2020-05-121-1/+1
| | | | | | | | | | | | | | | | | | | This omits system headers from the generated header dependency. System headers are not updated unless you upgrade the compiler. Nor do they contain CONFIG options, so fixdep does not need to parse them. Having said that, the effect of this optimization will be quite small because the kernel code generally does not include system headers except <stdarg.h>. Host programs include a lot of system headers, but there are not so many in the kernel tree. At first, keeping system headers in .*.cmd files might be useful to detect the compiler update, but there is no guarantee that <stdarg.h> is included from every file. So, I implemented a more reliable way in the previous commit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: remove *.tmp file when filechk failsMasahiro Yamada2020-01-151-8/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bartosz Golaszewski reports that when "make {menu,n,g,x}config" fails due to missing packages, a temporary file is left over, which is not ignored by git. For example, if GTK+ is not installed: $ make gconfig * * Unable to find the GTK+ installation. Please make sure that * the GTK+ 2.0 development package is correctly installed. * You need gtk+-2.0 gmodule-2.0 libglade-2.0 * scripts/kconfig/Makefile:208: recipe for target 'scripts/kconfig/gconf-cfg' failed make[1]: *** [scripts/kconfig/gconf-cfg] Error 1 Makefile:567: recipe for target 'gconfig' failed make: *** [gconfig] Error 2 $ git status HEAD detached at v5.4 Untracked files: (use "git add <file>..." to include in what will be committed) scripts/kconfig/gconf-cfg.tmp nothing added to commit but untracked files present (use "git add" to track) This is because the check scripts are run with filechk, which misses to clean up the temporary file on failure. When the line { $(filechk_$(1)); } > $@.tmp; ... fails, it exits immediately due to the 'set -e'. Use trap to make sure to delete the temporary file on exit. For extra safety, I replaced $@.tmp with $(dot-target).tmp to make it a hidden file. Reported-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: create modules.builtin without Makefile.modbuiltin or tristate.confMasahiro Yamada2020-01-061-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit bc081dd6e9f6 ("kbuild: generate modules.builtin") added infrastructure to generate modules.builtin, the list of all builtin modules. Basically, it works like this: - Kconfig generates include/config/tristate.conf, the list of tristate CONFIG options with a value in a capital letter. - scripts/Makefile.modbuiltin makes Kbuild descend into directories to collect the information of builtin modules. I am not a big fan of it because Kbuild ends up with traversing the source tree twice. I am not sure how perfectly it should work, but this approach cannot avoid false positives; even if the relevant CONFIG option is tristate, some Makefiles forces obj-m to obj-y. Some examples are: arch/powerpc/platforms/powermac/Makefile: obj-$(CONFIG_NVRAM:m=y) += nvram.o net/ipv6/Makefile: obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o net/netlabel/Makefile: obj-$(subst m,y,$(CONFIG_IPV6)) += netlabel_calipso.o Nobody has complained about (or noticed) it, so it is probably fine to have false positives in modules.builtin. This commit simplifies the implementation. Let's exploit the fact that every module has MODULE_LICENSE(). (modpost shows a warning if MODULE_LICENSE is missing. If so, 0-day bot would already have blocked such a module.) I added MODULE_FILE to <linux/module.h>. When the code is being compiled as builtin, it will be filled with the file path of the module, and collected into modules.builtin.info. Then, scripts/link-vmlinux.sh extracts the list of builtin modules out of it. This new approach fixes the false-positives above, but adds another type of false-positives; non-modular code may have MODULE_LICENSE() by mistake. This is not a big deal, it is just the code is always orphan. We can clean it up if we like. You can see cleanup examples by: $ git log --grep='make.* explicitly non-modular' To sum up, this commits deletes lots of code, but still produces almost equivalent results. Please note it does not increase the vmlinux size at all. As you can see in include/asm-generic/vmlinux.lds.h, the .modinfo section is discarded in the link stage. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: add stringify helper to quote a string passed to C filesMasahiro Yamada2020-01-061-0/+4
| | | | | | | Make $(squote)$(quote)...$(quote)$(squote) a helper macro. I will reuse it in the next commit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kbuild: rename any-prereq to newer-prereqsMasahiro Yamada2019-11-111-5/+5
| | | | | | | | | | | | | GNU Make manual says: $? The names of all the prerequisites that are newer than the target, with spaces between them. To reflect this, rename any-prereq to newer-prereqs, which is clearer and more intuitive. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: drop $(wildcard $^) check in if_changed* for faster rebuildMasahiro Yamada2019-11-111-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The incremental build of Linux kernel is pretty slow when lots of objects are compiled. The rebuild of allmodconfig may take a few minutes even when none of the objects needs to be rebuilt. The time-consuming part in the incremental build is the evaluation of if_changed* macros since they are used in the recipes to compile C and assembly source files into objects. I notice the following code in if_changed* is expensive: $(filter-out $(PHONY) $(wildcard $^),$^) In the incremental build, every object has its .*.cmd file, which contains the auto-generated list of included headers. So, $^ are expanded into the long list of the source file + included headers, and $(wildcard $^) checks whether they exist. It may not be clear why this check exists there. Here is the record of my research. [1] The first code addition into Kbuild This code dates back to 2002. It is the pre-git era. So, I copy-pasted it from the historical git tree. | commit 4a6db0791528c220655b063cf13fefc8470dbfee (HEAD) | Author: Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de> | Date: Mon Jun 17 00:22:37 2002 -0500 | | kbuild: Handle removed headers | | New and old way to handle dependencies would choke when a file | #include'd by other files was removed, since the dependency on it was | still recorded, but since it was gone, make has no idea what to do about | it (and would complain with "No rule to make <file> ...") | | We now add targets for all the previously included files, so make will | just ignore them if they disappear. | | diff --git a/Rules.make b/Rules.make | index 6ef827d3df39..7db5301ea7db 100644 | --- a/Rules.make | +++ b/Rules.make | @@ -446,7 +446,7 @@ if_changed = $(if $(strip $? \ | # execute the command and also postprocess generated .d dependencies | # file | | -if_changed_dep = $(if $(strip $? \ | +if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\ | $(filter-out $(cmd_$(1)),$(cmd_$@))\ | $(filter-out $(cmd_$@),$(cmd_$(1)))),\ | @set -e; \ | diff --git a/scripts/fixdep.c b/scripts/fixdep.c | index b5d7bee8efc7..db45bd1888c0 100644 | --- a/scripts/fixdep.c | +++ b/scripts/fixdep.c | @@ -292,7 +292,7 @@ void parse_dep_file(void *map, size_t len) | exit(1); | } | memcpy(s, m, p-m); s[p-m] = 0; | - printf("%s: \\\n", target); | + printf("deps_%s := \\\n", target); | m = p+1; | | clear_config(); | @@ -314,7 +314,8 @@ void parse_dep_file(void *map, size_t len) | } | m = p + 1; | } | - printf("\n"); | + printf("\n%s: $(deps_%s)\n\n", target, target); | + printf("$(deps_%s):\n", target); | } | | void print_deps(void) The "No rule to make <file> ..." error can be solved by passing -MP to the compiler, but I think the detection of header removal is a good feature. When a header is removed, all source files that previously included it should be re-compiled. This makes sure we has correctly got rid of #include directives of it. This is also related with the behavior of $?. The GNU Make manual says: $? The names of all the prerequisites that are newer than the target, with spaces between them. This does not explain whether a non-existent prerequisite is considered to be newer than the target. At this point of time, GNU Make 3.7x was used, where the $? did not include non-existent prerequisites. Therefore, $(filter-out FORCE $(wildcard $^),$^) was useful to detect the header removal, and to rebuild the related objects if it is the case. [2] Change of $? behavior Later, the behavior of $? was changed (fixed) to include prerequisites that did not exist. First, GNU Make commit 64e16d6c00a5 ("Various changes getting ready for the release of 3.81.") changed it, but in the release test of 3.81, it turned out to break the kernel build. See these: - http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html - https://savannah.gnu.org/bugs/?16002 - https://savannah.gnu.org/bugs/?16051 Then, GNU Make commit 6d8d9b74d9c5 ("Numerous updates to tests for issues found on Cygwin and Windows.") reverted it for the 3.81 release to give Linux kernel time to adjust to the new behavior. After the 3.81 release, GNU Make commit 7595f38f62af ("Fixed a number of documentation bugs, plus some build/install issues:") re-added it. [3] Adjustment to the new $? behavior on Kbuild side Meanwhile, the kernel build was changed by commit 4f1933620f57 ("kbuild: change kbuild to not rely on incorrect GNU make behavior") to adjust to the new $? behavior. [4] GNU Make 3.82 released in 2010 GNU Make 3.82 was the first release that integrated the correct $? behavior. At this point, Kbuild dealt with GNU Make versions with different $? behaviors. 3.81 or older: $? does not contain any non-existent prerequisite. $(filter-out $(PHONY) $(wildcard $^),$^) was useful to detect removed include headers. 3.82 or newer: $? contains non-existent prerequisites. When a header is removed, it appears in $?. $(filter-out $(PHONY) $(wildcard $^),$^) became a redundant check. With the correct $? behavior, we could have dropped the expensive check for 3.82 or later, but we did not. (Maybe nobody noticed this optimization.) [5] The .SECONDARY special target trips up $? Some time later, I noticed $? did not work as expected under some circumstances. As above, $? should contain non-existent prerequisites, but the ones specified as SECONDARY do not appear in $?. I asked this in GNU Make ML, and it seems a bug: https://lists.gnu.org/archive/html/bug-make/2019-01/msg00001.html Since commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"), all files, including headers listed in .*.cmd files, are treated as secondary. So, we are back into the incorrect $? behavior. If we Kbuild want to react to the header removal, we need to keep $(filter-out $(PHONY) $(wildcard $^),$^) but this makes the rebuild so slow. [Summary] - I believe noticing the header removal and recompiling related objects is a nice feature for the build system. - If $? worked correctly, $(filter-out $(PHONY),$?) would be enough to detect the header removal. - Currently, $? does not work correctly when used with .SECONDARY, and Kbuild is hit by this bug. - I filed a bug report for this, but not fixed yet as of writing. - Currently, the header removal is detected by the following expensive code: $(filter-out $(PHONY) $(wildcard $^),$^) - I do not want to revert commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"). Specifying .SECONDARY globally is clean, and it matches to the Kbuild policy. This commit proactively removes the expensive check since it makes the incremental build faster. A downside is Kbuild will no longer be able to notice the header removal. You can confirm it by the full-build followed by a header removal, and then re-build. $ make defconfig all [ full build ] $ rm include/linux/device.h $ make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CHK include/generated/compile.h Kernel: arch/x86/boot/bzImage is ready (#11) Building modules, stage 2. MODPOST 12 modules Previously, Kbuild noticed a missing header and emits a build error. Now, Kbuild is fine with it. This is an unusual corner-case, not a big deal. Once the $? bug is fixed in GNU Make, everything will work fine. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: remove ar-option and KBUILD_ARFLAGSMasahiro Yamada2019-10-011-5/+0
| | | | | | | | | | | | | | | | Commit 40df759e2b9e ("kbuild: Fix build with binutils <= 2.19") introduced ar-option and KBUILD_ARFLAGS to deal with old binutils. According to Documentation/process/changes.rst, the current minimal supported version of binutils is 2.21 so you can assume the 'D' option is always supported. Not only GNU ar but also llvm-ar supports it. With the 'D' option hard-coded, there is no more user of ar-option or KBUILD_ARFLAGS. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
* kbuild: remove unused objectify macroMasahiro Yamada2019-07-271-3/+0
| | | | | | | Commit 415008af3219 ("docs-rst: convert lsm from DocBook to ReST") removed the last users of this macro. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: remove unused hostcc-optionMasahiro Yamada2019-07-171-5/+0
| | | | | | We can re-add this whenever it is needed. At this moment, it is unused. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* Merge tag 'kbuild-v5.3' of ↵Linus Torvalds2019-07-131-17/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - remove headers_{install,check}_all targets - remove unreasonable 'depends on !UML' from CONFIG_SAMPLES - re-implement 'make headers_install' more cleanly - add new header-test-y syntax to compile-test headers - compile-test exported headers to ensure they are compilable in user-space - compile-test headers under include/ to ensure they are self-contained - remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value flags - add -Werror=unknown-warning-option for Clang - add 128-bit built-in types support to genksyms - fix missed rebuild of modules.builtin - propagate 'No space left on device' error in fixdep to Make - allow Clang to use its integrated assembler - improve some coccinelle scripts - add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute path for $(srctree). - do not ignore errors when compression utility is missing - misc cleanups * tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits) kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix kbuild: Inform user to pass ARCH= for make mrproper kbuild: fix compression errors getting ignored kbuild: add a flag to force absolute path for srctree kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree kbuild: remove src and obj from the top Makefile scripts/tags.sh: remove unused environment variables from comments scripts/tags.sh: drop SUBARCH support for ARM kbuild: compile-test kernel headers to ensure they are self-contained kheaders: include only headers into kheaders_data.tar.xz kheaders: remove meaningless -R option of 'ls' kbuild: support header-test-pattern-y kbuild: do not create wrappers for header-test-y kbuild: compile-test exported headers to ensure they are self-contained init/Kconfig: add CONFIG_CC_CAN_LINK kallsyms: exclude kasan local symbols on s390 kbuild: add more hints about SUBDIRS replacement coccinelle: api/stream_open: treat all wait_.*() calls as blocking coccinelle: put_device: Add a cast to an expression for an assignment coccinelle: put_device: Adjust a message construction ...
| * kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefixMasahiro Yamada2019-07-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch/mips/Makefile passes prefixes that start with '-' to cc-cross-prefix when $(tool-archpref) evaluates to the empty string. They are filtered-out before the $(shell ...) invocation. Otherwise, 'command -v' would be confused. $ command -v -linux-gcc bash: command: -l: invalid option command: usage: command [-pVv] command [arg ...] Since commit 913ab9780fc0 ("kbuild: use more portable 'command -v' for cc-cross-prefix"), cc-cross-prefix throws away the stderr output, so the console is not polluted in any way. This is not a big deal in practice, but I see a slightly better taste in adding '--' to teach it that '-linux-gcc' is an argument instead of a command option. This will cause extra forking of subshell, but it will not be noticeable performance regression. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: save $(strip ...) for calling if_changed and friendsMasahiro Yamada2019-07-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The string returned by $(filter-out ...) does not contain any leading or trailing spaces. With the previous commit, 'any-prereq' no longer contains any excessive spaces. Nor does 'cmd-check' since it expands to a $(filter-out ...) call. So, only the space that matters is the one between 'any-prereq' and 'cmd-check'. By removing it from the code, we can save $(strip ...) evaluation. This refactoring is possible because $(any-prereq)$(cmd-check) is only passed to the first argument of $(if ...), so we are only interested in whether or not it is empty. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: save $(strip ...) for calling any-prepreqMasahiro Yamada2019-07-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The string returned by $(filter-out ...) does not contain any leading or trailing spaces. So, only the space that matters is the one between $(filter-out $(PHONY),$?) and $(filter-out $(PHONY) $(wildcard $^),$^) By removing it from the code, we can save $(strip ...) evaluation. This refactoring is possible because $(any-prereq) is only passed to the first argument of $(if ...), so we are only interested in whether or not it is empty. This is also the prerequisite for the next commit. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: rename arg-check to cmd-checkMasahiro Yamada2019-07-011-7/+7
| | | | | | | | | | | | | | | | I prefer 'cmd-check' for consistency. We have 'echo-cmd', 'cmd', 'cmd_and_fixdep', etc. in this file. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: move hdr-inst shorthand to top MakefileMasahiro Yamada2019-06-151-6/+0
| | | | | | | | | | | | | | Now that hdr-inst is used only in the top Makefile, move it there from scripts/Kbuild.include. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | docs: kbuild: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-06-141-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | The kbuild documentation clearly shows that the documents there are written at different times: some use markdown, some use their own peculiar logic to split sections. Convert everything to ReST without affecting too much the author's style and avoiding adding uneeded markups. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* kbuild: use more portable 'command -v' for cc-cross-prefixMasahiro Yamada2019-06-071-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To print the pathname that will be used by shell in the current environment, 'command -v' is a standardized way. [1] 'which' is also often used in scripts, but it is less portable. When I worked on commit bd55f96fa9fc ("kbuild: refactor cc-cross-prefix implementation"), I was eager to use 'command -v' but it did not work. (The reason is explained below.) I kept 'which' as before but got rid of '> /dev/null 2>&1' as I thought it was no longer needed. Sorry, I was wrong. It works well on my Ubuntu machine, but Alexey Brodkin reports noisy warnings on CentOS7 when 'which' fails to find the given command in the PATH environment. $ which foo which: no foo in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin) Given that behavior of 'which' depends on system (and it may not be installed by default), I want to try 'command -v' once again. The specification [1] clearly describes the behavior of 'command -v' when the given command is not found: Otherwise, no output shall be written and the exit status shall reflect that the name was not found. However, we need a little magic to use 'command -v' from Make. $(shell ...) passes the argument to a subshell for execution, and returns the standard output of the command. Here is a trick. GNU Make may optimize this by executing the command directly instead of forking a subshell, if no shell special characters are found in the command and omitting the subshell will not change the behavior. In this case, no shell special character is used. So, Make will try to run it directly. However, 'command' is a shell-builtin command, then Make would fail to find it in the PATH environment: $ make ARCH=m68k defconfig make: command: Command not found make: command: Command not found make: command: Command not found In fact, Make has a table of shell-builtin commands because it must ask the shell to execute them. Until recently, 'command' was missing in the table. This issue was fixed by the following commit: | commit 1af314465e5dfe3e8baa839a32a72e83c04f26ef | Author: Paul Smith <psmith@gnu.org> | Date: Sun Nov 12 18:10:28 2017 -0500 | | * job.c: Add "command" as a known shell built-in. | | This is not a POSIX shell built-in but it's common in UNIX shells. | Reported by Nick Bowler <nbowler@draconx.ca>. Because the latest release is GNU Make 4.2.1 in 2016, this commit is not included in any released versions. (But some distributions may have back-ported it.) We need to trick Make to spawn a subshell. There are various ways to do so: 1) Use a shell special character '~' as dummy $(shell : ~; command -v $(c)gcc) 2) Use a variable reference that always expands to the empty string (suggested by David Laight) $(shell command$${x:+} -v $(c)gcc) 3) Use redirect $(shell command -v $(c)gcc 2>/dev/null) I chose 3) to not confuse people. The stderr would not be polluted anyway, but it will provide extra safety, and is easy to understand. Tested on Make 3.81, 3.82, 4.0, 4.1, 4.2, 4.2.1 [1] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html Fixes: bd55f96fa9fc ("kbuild: refactor cc-cross-prefix implementation") Cc: linux-stable <stable@vger.kernel.org> # 5.1 Reported-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Alexey Brodkin <abrodkin@synopsys.com>
* treewide: Add SPDX license identifier - KbuildGreg Kroah-Hartman2019-05-301-0/+1
| | | | | | | | | | | | | | | | Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0 Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: drop support for cc-ldoptionNick Desaulniers2019-05-201-5/+0
| | | | | | | | | | | | If you want to see if your linker supports a certain flag, then ask the linker directly with ld-option (not the compiler with cc-ldoption). Checking for linker flag support is an antipattern that complicates the usage of various linkers other than bfd via -fuse-ld={bfd|gold|lld}. Cc: clang-built-linux@googlegroups.com Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: remove 'addtree' and 'flags' magic for header search pathsMasahiro Yamada2019-05-181-8/+0
| | | | | | | | | | | | | | | | | | | 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 <yamada.masahiro@socionext.com>
* kbuild: remove cc-version macroMasahiro Yamada2019-03-041-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no more direct user of this macro; it is only used by cc-ifversion. Calling this macro is not efficient since it invokes the compiler to get the compiler version. CONFIG_GCC_VERSION is already calculated in the Kconfig stage, so Makefile can reuse it. Here is a note about the slight difference between cc-version and CONFIG_GCC_VERSION: When using Clang, cc-version is evaluated to '0402' because Clang defines __GNUC__ and __GNUC__MINOR__, and looks like GCC 4.2 in the version point of view. On the other hand, CONFIG_GCC_VERSION=0 when $(CC) is clang. There are currently two users of cc-ifversion: arch/mips/loongson64/Platform arch/powerpc/Makefile They are not affected by this change. The format of cc-version is <major><minor>, while CONFIG_GCC_VERSION <major><minor><patch>. I adjusted cc-ifversion for the difference of the number of digits. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: refactor cc-cross-prefix implementationMasahiro Yamada2019-02-271-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - $(word 1, <text>) is equivalent to $(firstword <text>) - hardcode "gcc" instead of $(CC) - minimize the shell script part A little more notes in case $(filter-out -%, ...) is not clear. arch/mips/Makefile passes prefixes depending on the configuration. CROSS_COMPILE := $(call cc-cross-prefix, $(tool-archpref)-linux- \ $(tool-archpref)-linux-gnu- $(tool-archpref)-unknown-linux-gnu-) In the Kconfig stage (e.g. when you run 'make defconfig'), neither CONFIG_32BIT nor CONFIG_64BIT is defined. So, $(tool-archpref) is empty. As a result, "-linux -linux-gnu- -unknown-linux-gnu" is passed into cc-cross-prefix. The command 'which' assumes arguments starting with a hyphen as command options, then emits the following messages: Illegal option -l Illegal option -l Illegal option -u I think it is strange to define CROSS_COMPILE depending on the CONFIG options since you need to feed $(CC) to Kconfig, but it is how MIPS Makefile currently works. Anyway, it would not hurt to filter-out invalid strings beforehand. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: add real-prereqs shorthand for $(filter-out FORCE,$^)Masahiro Yamada2019-01-281-0/+4
| | | | | | | | | | | | | | | | | | | 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 <yamada.masahiro@socionext.com> Acked-by: Rob Herring <robh@kernel.org>
* kbuild: remove unused baseprereqMasahiro Yamada2019-01-141-4/+0
| | | | | | | Commit eea199b445f6 ("kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX") removed the last users of this macro. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: use assignment instead of define ... endef for filechk_* rulesMasahiro Yamada2019-01-061-4/+4
| | | | | | | | | | | | You do not have to use define ... endef for filechk_* rules. For simple cases, the use of assignment looks cleaner, IMHO. I updated the usage for scripts/Kbuild.include in case somebody misunderstands the 'define ... endif' is the requirement. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* kbuild: change filechk to surround the given command with { }Masahiro Yamada2019-01-061-1/+1
| | | | | | | | | | | 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 <yamada.masahiro@socionext.com>
* Merge tag 'kbuild-v4.21' of ↵Linus Torvalds2018-12-291-42/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 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 cleanups Treewide 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 ./Kbuild Modpost: - remove unused -M, -K options - fix false positive warnings about section mismatch - use simple devtable lookup instead of linker magic - misc cleanups Coccinelle: - relax boolinit.cocci checks for overall consistency - fix warning messages of boolinit.cocci Other 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 ...
| * kbuild: move .SECONDARY special target to Kbuild.includeMasahiro Yamada2018-12-021-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers"), I missed one important feature of the .SECONDARY target: .SECONDARY with no prerequisites causes all targets to be treated as secondary. ... which agrees with the policy of Kbuild. Let's move it to scripts/Kbuild.include, with no prerequisites. Note: If an intermediate file is generated by $(call if_changed,...), you still need to add it to "targets" so its .*.cmd file is included. The arm/arm64 crypto files are generated by $(call cmd,shipped), so they do not need to be added to "targets", but need to be added to "clean-files" so "make clean" can properly clean them away. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| * kbuild: refactor if_changedMasahiro Yamada2018-12-011-2/+1
| | | | | | | | | | | | '@set -e; $(echo-cmd) $(cmd_$(1)' can be replaced with '$(cmd)'. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 20:55:31 +0100