- 26 Jan, 2023 14 commits
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Nathan Chancellor authored
This option masks all unused command line argument warnings, which can hide potential issues, such as an architecture Makefile adding an unsupported flag to KBUILD_AFLAGS or KBUILD_CFLAGS, which will cause all as-option and cc-options to silently fail due to -Werror with no indication as to why in the main kernel build. Remove this flag so that warnings of this nature can be caught early and obviously in a build. Signed-off-by:
Nathan Chancellor <nathan@kernel.org> Reviewed-by:
Nick Desaulniers <ndesaulniers@google.com> Tested-by:
Linux Kernel Functional Testing <lkft@linaro.org> Tested-by:
Anders Roxell <anders.roxell@linaro.org> Signed-off-by:
Masahiro Yamada <masahiroy@kernel.org>
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Nathan Chancellor authored
Currently, these warnings are hidden with -Qunused-arguments in KBUILD_CPPFLAGS. Once that option is removed, these warnings should be turned into hard errors to make unconditionally added but unsupported flags for the current compilation mode or target obvious due to a failed build; otherwise, the warnings might just be ignored if the build log is not checked. Link: https://github.com/ClangBuiltLinux/linux/issues/1587Signed-off-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it warns: clang-16: error: argument unused during compilation: '-mhard-float' [-Werror,-Wunused-command-line-argument] Similar to commit 84edc2ef ("selftest/fpu: avoid clang warning"), just add this flag to GCC builds. Commit 0f0727d9 ("drm/amd/display: readd -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines") added '-msse2' to prevent clang from emitting software floating point routines. Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Tested-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it warns while building objects in the purgatory folder: clang-16: error: argument unused during compilation: '-MD' [-Werror,-Wunused-command-line-argument] '-MMD' is always passed to the preprocessor via c_flags, even when KBUILD_CFLAGS is overridden in a folder, so clang complains the addition of '-MD' will be unused. Remove '-MD' to clear up this warning, as it is unnecessary with '-MMD'. Additionally, '-c' is also unnecessary, remove it while in the area. Signed-off-by:
Heiko Carstens <hca@linux.ibm.com> Reviewed-by:
Sven Schnelle <svens@linux.ibm.com> Tested-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it points out that there is a linking phase flag added to CFLAGS, which will only be used for compiling clang-16: error: argument unused during compilation: '-shared' [-Werror,-Wunused-command-line-argument] '-shared' is already present in ldflags-y so it can just be dropped. Fixes: 2b2a2584 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") Signed-off-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it warns: clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument] The compiler's '-s' flag is a linking option (it is passed along to the linker directly), which means it does nothing when the linker is not invoked by the compiler. The kernel builds all .o files with '-c', which stops the compilation pipeline before linking, so '-s' can be safely dropped from KBUILD_AFLAGS_64. Signed-off-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it warns: clang-16: error: argument unused during compilation: '-fno-stack-clash-protection' [-Werror,-Wunused-command-line-argument] This warning happens because vgettimeofday-32.c gets its base CFLAGS from the main kernel, which may contain flags that are only supported on a 64-bit target but not a 32-bit one, which is the case here. -fstack-clash-protection and its negation are only suppported by the 64-bit powerpc target but that flag is included in an invocation for a 32-bit powerpc target, so clang points out that while the flag is one that it recognizes, it is not actually used by this compiler job. To eliminate the warning, remove -fno-stack-clash-protection from vgettimeofday-32.c's CFLAGS when using clang, as has been done for other flags previously. Signed-off-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, there are several warnings in the PowerPC vDSO: clang-16: error: -Wl,-soname=linux-vdso32.so.1: 'linker' input unused [-Werror,-Wunused-command-line-argument] clang-16: error: -Wl,--hash-style=both: 'linker' input unused [-Werror,-Wunused-command-line-argument] clang-16: error: argument unused during compilation: '-shared' [-Werror,-Wunused-command-line-argument] clang-16: error: argument unused during compilation: '-nostdinc' [-Werror,-Wunused-command-line-argument] clang-16: error: argument unused during compilation: '-Wa,-maltivec' [-Werror,-Wunused-command-line-argument] The first group of warnings point out that linker flags were being added to all invocations of $(CC), even though they will only be used during the final vDSO link. Move those flags to ldflags-y. The second group of warnings are compiler or assembler flags that will be unused during linking. Filter them out from KBUILD_CFLAGS so that they are not used during linking. Additionally, '-z noexecstack' was added directly to the ld_and_check rule in commit 1d53c019 ("powerpc/vdso: link with -z noexecstack") but now that there is a common ldflags variable, it can be moved there. Signed-off-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it warns: clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument] The compiler's '-s' flag is a linking option (it is passed along to the linker directly), which means it does nothing when the linker is not invoked by the compiler. The kernel builds all .o files with '-c', which stops the compilation pipeline before linking, so '-s' can be safely dropped from ASFLAGS. Signed-off-by:
Segher Boessenkool <segher@kernel.crashing.org> Tested-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Nathan Chancellor authored
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it points out that KBUILD_AFLAGS contains a linker flag, which will be unused: clang: error: -Wl,-a32: 'linker' input unused [-Werror,-Wunused-command-line-argument] This was likely supposed to be '-Wa,-a$(BITS)'. However, this change is unnecessary, as all supported versions of clang and gcc will pass '-a64' or '-a32' to GNU as based on the value of '-m'; the behavior of the latest stable release of the oldest supported major version of each compiler is shown below and each compiler's latest release exhibits the same behavior (GCC 12.2.0 and Clang 15.0.6). $ powerpc64-linux-gcc --version | head -1 powerpc64-linux-gcc (GCC) 5.5.0 $ powerpc64-linux-gcc -m64 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as ' .../as -a64 -mppc64 -many -mbig -o /dev/null /tmp/cctwuBzZ.s $ powerpc64-linux-gcc -m32 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as ' .../as -a32 -mppc -many -mbig -o /dev/null /tmp/ccaZP4mF.sg $ clang --version | head -1 Ubuntu clang version 11.1.0-++20211011094159+1fdec59bffc1-1~exp1~20211011214622.5 $ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \ -x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as "/usr/bin/powerpc64-linux-gnu-as" "-a64" "-mppc64" "-many" "-o" "/dev/null" "/tmp/null-80267c.s" $ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \ -x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as "/usr/bin/powerpc64-linux-gnu-as" "-a32" "-mppc" "-many" "-o" "/dev/null" "/tmp/null-ab8f8d.s" Remove this flag altogether to avoid future issues. Fixes: 1421dc6d ("powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS") Signed-off-by: -
Nick Desaulniers authored
as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can cause as-option to fail unexpectedly when CONFIG_WERROR is set, because clang will emit -Werror,-Wunused-command-line-argument for various -m and -f flags in KBUILD_CFLAGS for assembler sources. Callers of as-option and as-instr should be adding flags to KBUILD_AFLAGS / aflags-y, not KBUILD_CFLAGS / cflags-y. Use KBUILD_AFLAGS in all macros to clear up the initial problem. Unfortunately, -Wunused-command-line-argument can still be triggered with clang by the presence of warning flags or macro definitions because '-x assembler' is used, instead of '-x assembler-with-cpp', which will consume these flags. Switch to '-x assembler-with-cpp' in places where '-x assembler' is used, as the compiler is always used as the driver for out of line assembler sources in the kernel. Finally, add -Werror to these macros so that they behave consistently whether or not CONFIG_WERROR is set. [nathan: Reworded and expanded on problems in commit message Use '-x assembler-with-cpp' in a couple more places] Link: https://github.com/ClangBuiltLinux/linux/issues/1699Suggested-by: -
Nathan Chancellor authored
A future change will switch as-option to use KBUILD_AFLAGS instead of KBUILD_CFLAGS to allow clang to drop -Qunused-arguments, which may cause issues if the flag being tested requires a flag previously added to KBUILD_CFLAGS but not KBUILD_AFLAGS. Use cc-option for cflags additions so that the flags are tested properly. Signed-off-by:
Thomas Bogendoerfer <tsbogend@alpha.franken.de> Reviewed-by:
Philippe Mathieu-Daudé <philmd@linaro.org> Tested-by:
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Nathan Chancellor authored
-Wa,-msoft-float is tested with as-option, which will be a problem for clang with an upcoming change to move as-option to use KBUILD_AFLAGS instead of KBUILD_CFLAGS due to a lack of '-mno-abicalls' in KBUILD_AFLAGS at the point that this check occurs; $(cflags-y) is added to KBUILD_AFLAGS towards the end of this file. clang: error: ignoring '-fno-PIE' option as it cannot be used with implicit usage of -mabicalls and the N64 ABI [-Werror,-Woption-ignored] This could be resolved by switching to a cc-option check but '$(cflags-y)' would need to be added so that '-mno-abicalls' is present for the test. However, this check is no longer necessary, as -msoft-float is supported by all supported assembler versions (GNU as 2.25+ and LLVM 11+). Eliminate GAS_HAS_SET_HARDFLOAT and all of its uses, inlining SET_HARDFLOAT where necessary. Link: https://lore.kernel.org/202209101939.bvk64Fok-lkp@intel.com/Reported-by:
kernel test robot <lkp@intel.com> Signed-off-by:
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Nick Desaulniers authored
as-option tests new options using KBUILD_CFLAGS, which causes problems when using as-option to update KBUILD_AFLAGS because many compiler options are not valid assembler options. This will be fixed in a follow up patch. Before doing so, move the assembler test for -Wa,-mrelax-relocations=no from using as-option to cc-option. Link: https://lore.kernel.org/llvm/CAK7LNATcHt7GcXZ=jMszyH=+M_LC9Qr6yeAGRCBbE6xriLxtUQ@mail.gmail.com/Suggested-by:
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- 22 Jan, 2023 26 commits
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Thomas Weißschuh authored
If the kheaders archive generation is interrupted then this directory may be left on disk and not ignored by git. By using the standard naming schema for temporary files and directories the default .gitignore and "make clean" rules will apply. Suggested-by:
Nicolas Schier <nicolas@fjasle.eu> Suggested-by:
Thomas Weißschuh <linux@weissschuh.net> Reviewed-by:
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Thomas Weißschuh authored
Reuse the standard naming schema for temporary files also for temporary directories. Such a directory will be used by the kheaders generation. Signed-off-by:
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Jani Nikula authored
Adding any rst quoting seems to be controversial, but at least try to unify the existing quoting a bit, without adding new ones. Signed-off-by:
Jani Nikula <jani.nikula@intel.com> Signed-off-by:
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Jani Nikula authored
Remove the leading whitespaces, and clean up indentation and whitespace in general. Although the diff looks massive, it's trivial with 'diff -w' or 'git show -w'. Signed-off-by:
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Jani Nikula authored
Drop the manually updated section numbering. It's hard to maintain, and indeed hasn't been updated when sections 3.4 and 7.8 were dropped. Update all the section references to rst references. Signed-off-by:
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Jani Nikula authored
This is not something that should be manually updated. Signed-off-by:
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Jani Nikula authored
The "Kbuild syntax for exported headers" section should not be under "Architecture Makefiles" in hierarchy. Bump the header underline from "-" to "=". Signed-off-by:
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Jani Nikula authored
The MAINTAINERS repository entry specifies "kconfig" as the branch, but the repository itself has "kbuild". Signed-off-by:
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Masahiro Yamada authored
$(tmp-target) is a better fit for local use like this. Signed-off-by:
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Masahiro Yamada authored
scripts/ is a better place to generate files used treewide. With target.json moved to scripts/, you do not need to add target.json to no-clean-files or MRPROPER_FILES. 'make clean' does not visit scripts/, but 'make mrproper' does. Signed-off-by:
Miguel Ojeda <ojeda@kernel.org> Tested-by:
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Masahiro Yamada authored
fixdep is designed only for parsing text files. read_file() appends a terminating null byte ('\0') and parse_config_file() calls strstr() to search for CONFIG options. rustc outputs *.rlib, *.rmeta, *.so to dep-info. fixdep needs them in the dependency, but there is no point in parsing such binary files. Signed-off-by: -
Masahiro Yamada authored
The dep files (*.d files) emitted by C compilers usually contain the deduplicated list of included files. One exceptional case is when a header is included by the -include command line option, and also by #include directive. For example, the top Makefile adds the command line option, "-include $(srctree)/include/linux/kconfig.h". You do not need to include <linux/kconfig.h> in every source file. In fact, include/linux/kconfig.h is listed twice in many .*.cmd files due to include/linux/xarray.h having "#include <linux/kconfig.h>". I did not fix that since it is a small redundancy. However, this is more annoying for rustc. rustc emits the dependency for each emission type. For example, cmd_rustc_library emits dep-info, obj, and metadata. So, the emitted *.d file contains the dependency for those 3 targets, which makes fixdep parse the same file 3 times. $ grep rust/alloc/raw_vec.rs rust/.alloc.o.cmd rust/alloc/raw_vec.rs \ rust/alloc/raw_vec.rs \ rust/alloc/raw_vec.rs \ To skip the second parsing, this commit adds a hash table for parsed files, just like we did for CONFIG options. Signed-off-by:Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
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Masahiro Yamada authored
Change the hash table code so it will be easier to add the second table. Signed-off-by:
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Masahiro Yamada authored
rustc may put comments in dep-info, so sed is used to drop them before passing it to fixdep. Now that fixdep can remove comments, Makefiles do not need to run sed. Signed-off-by:
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Masahiro Yamada authored
fixdep parses dependency files (*.d) emitted by the compiler. *.d files are Makefiles describing the dependencies of the main source file. fixdep understands minimal Makefile syntax. It works well enough for GCC and Clang, but not for rustc. This commit improves the parser a little more for better processing comments, escape sequences, etc. My main motivation is to drop comments. rustc may output comments (e.g. env-dep). Currentyly, rustc build rules invoke sed to remove comments, but it is more efficient to do it in fixdep. Signed-off-by:
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Masahiro Yamada authored
In Kbuild, two different rules must not write to the same file, but it happens when compiling rust source files. For example, set CONFIG_SAMPLE_RUST_MINIMAL=m and run the following: $ make -j$(nproc) samples/rust/rust_minimal.o samples/rust/rust_minimal.rsi \ samples/rust/rust_minimal.s samples/rust/rust_minimal.ll [snip] RUSTC [M] samples/rust/rust_minimal.o RUSTC [M] samples/rust/rust_minimal.rsi RUSTC [M] samples/rust/rust_minimal.s RUSTC [M] samples/rust/rust_minimal.ll mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:334: samples/rust/rust_minimal.ll] Error 1 make[3]: *** Waiting for unfinished jobs.... mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:309: samples/rust/rust_minimal.o] Error 1 mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:326: samples/rust/rust_minimal.s] Error 1 make[2]: *** [scripts/Makefile.build:504: samples/rust] Error 2 make[1]: *** [scripts/Makefile.build:504: samples] Error 2 make: *** [Makefile:2008: .] Error 2 The reason for the error is that 4 threads running in parallel renames the same file, samples/rust/rust_minimal.d. This does not happen when compiling C or assembly files because -Wp,-MMD,$(depfile) explicitly specifies the dependency filepath. $(depfile) is a unique path for each target. Currently, rustc is only given --out-dir and --emit=<list-of-types> So, all the rust build rules output the dep-info into the default <CRATE_NAME>.d, which causes the path conflict. Fortunately, the --emit option is able to specify the output path individually, with the form --emit=<type>=<path>. Add --emit=dep-info=$(depfile) to the common part. Also, remove the redundant --out-dir because the output path is specified for each type. The code gets much cleaner because we do not need to rename *.d files. Signed-off-by: -
Masahiro Yamada authored
Remove _host*_flags. No functional change is intended. Signed-off-by:
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Masahiro Yamada authored
cmd_dt_S_dtb and cmd_dt_S_dtbo are almost the same; the only difference is the prefix of the begin/end symbols. (__dtb vs __dtbo) Signed-off-by:
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Masahiro Yamada authored
The cmd-check for KBUILD_NOCMDDEP=1 may not be clear until you see commit c4d5ee13 ("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:
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Masahiro Yamada authored
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 authored
The top .gitignore comments about how to detect files breaking .gitignore rules, but people rarely care about it. Add a new W=1 warning to detect files that are tracked but ignored by git. If git is not installed or the source tree is not tracked by git at all, this script does not print anything. Running it on v6.2-rc1 detected the following: $ make W=1 misc-check Documentation/devicetree/bindings/.yamllint: warning: ignored by one of the .gitignore files drivers/clk/.kunitconfig: warning: ignored by one of the .gitignore files drivers/gpu/drm/tests/.kunitconfig: warning: ignored by one of the .gitignore files drivers/hid/.kunitconfig: warning: ignored by one of the .gitignore files fs/ext4/.kunitconfig: warning: ignored by one of the .gitignore files fs/fat/.kunitconfig: warning: ignored by one of the .gitignore files kernel/kcsan/.kunitconfig: warning: ignored by one of the .gitignore files lib/kunit/.kunitconfig: warning: ignored by one of the .gitignore files mm/kfence/.kunitconfig: warning: ignored by one of the .gitignore files tools/testing/selftests/arm64/tags/.gitignore: warning: ignored by one of the .gitignore files tools/testing/selftests/arm64/tags/Makefile: warning: ignored by one of the .gitignore files tools/testing/selftests/arm64/tags/run_tags_test.sh: warning: ignored by one of the .gitignore files tools/testing/selftests/arm64/tags/tags_test.c: warning: ignored by one of the .gitignore files These are ignored by the '.*' or 'tags' in the top .gitignore, but there is no rule to negate it. You might be tempted to do 'git add -f' but I want to have the real issue fixed (by fixing a .gitignore, or by renaming files, etc.). Signed-off-by:
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Masahiro Yamada authored
Recent git versions do not accept the noted command. $ git ls-files -i --exclude-standard fatal: ls-files -i must be used with either -o or -c The -c was implied before, but we need to make it explicit since git commit b338e9f66873 ("ls-files: error out on -i unless -o or -c are specified"). Also, replace --exclude-standard with --exclude-per-directory=.gitignore so that everyone will get consistent results. git-ls-files(1) says: --exclude-standard Add the standard Git exclusions: .git/info/exclude, .gitignore in each directory, and the user's global exclusion file. We cannot predict what is locally added to .git/info/exclude or the user's global exclusion file. We can only manage .gitignore files committed to the repository. Signed-off-by: -
Masahiro Yamada authored
More than one year has passed since the copied *.[cS] files were removed from arch/*/boot/compressed/. Signed-off-by: -
Masahiro Yamada authored
The top Makefile sets KBUILD_VERBOSE to 0 by default, it looks weird now because V=1 and V=2 can be OR'ed as V=12. The default should be empty. Signed-off-by:
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Masahiro Yamada authored
Commit a6de553d ("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:
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Masahiro Yamada authored
Some scripts increase the verbose level when V=1, but others when not V=0. I think the former is correct because V=2 is not a log level but a switch to print the reason for rebuilding. Signed-off-by:
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