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mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-14 14:34:28 +08:00
linux/tools/build
Arnaldo Carvalho de Melo 41caff459a tools build: Filter out options and warnings not supported by clang
These make the feature check fail when using clang, so remove them just
like is done in tools/perf/Makefile.config to build perf itself.

Adding -Wno-compound-token-split-by-macro to tools/perf/Makefile.config
when building with clang is also necessary to avoid these warnings
turned into errors (-Werror):

    CC      /tmp/build/perf/util/scripting-engines/trace-event-perl.o
  In file included from util/scripting-engines/trace-event-perl.c:35:
  In file included from /usr/lib64/perl5/CORE/perl.h:4085:
  In file included from /usr/lib64/perl5/CORE/hv.h:659:
  In file included from /usr/lib64/perl5/CORE/hv_func.h:34:
  In file included from /usr/lib64/perl5/CORE/sbox32_hash.h:4:
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: error: '(' and '{' tokens introducing statement expression appear in different macro expansion contexts [-Werror,-Wcompound-token-split-by-macro]
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:80:38: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
  #define ZAPHOD32_SCRAMBLE32(v,prime) STMT_START {  \
                                       ^~~~~~~~~~
  /usr/lib64/perl5/CORE/perl.h:737:29: note: expanded from macro 'STMT_START'
  #   define STMT_START   (void)( /* gcc supports "({ STATEMENTS; })" */
                                ^
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: note: '{' token is here
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:80:49: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
  #define ZAPHOD32_SCRAMBLE32(v,prime) STMT_START {  \
                                                  ^
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: error: '}' and ')' tokens terminating statement expression appear in different macro expansion contexts [-Werror,-Wcompound-token-split-by-macro]
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:87:41: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
      v ^= (v>>23);                       \
                                          ^
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: note: ')' token is here
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:88:3: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
  } STMT_END
    ^~~~~~~~
  /usr/lib64/perl5/CORE/perl.h:738:21: note: expanded from macro 'STMT_END'
  #   define STMT_END     )
                          ^

Please refer to the discussion on the Link: tag below, where Nathan
clarifies the situation:

<quote>
acme> And then get to the problems at the end of this message, which seem
acme> similar to the problem described here:
acme>
acme> From  Nathan Chancellor <>
acme> Subject	[PATCH] mwifiex: Remove unnecessary braces from HostCmd_SET_SEQ_NO_BSS_INFO
acme>
acme> https://lkml.org/lkml/2020/9/1/135
acme>
acme> So perhaps in this case its better to disable that
acme> -Werror,-Wcompound-token-split-by-macro when building with clang?

Yes, I think that is probably the best solution. As far as I can tell,
at least in this file and context, the warning appears harmless, as the
"create a GNU C statement expression from two different macros" is very
much intentional, based on the presence of PERL_USE_GCC_BRACE_GROUPS.
The warning is fixed in upstream Perl by just avoiding creating GNU C
statement expressions using STMT_START and STMT_END:

  https://github.com/Perl/perl5/issues/18780
  https://github.com/Perl/perl5/pull/18984

If I am reading the source code correctly, an alternative to disabling
the warning would be specifying -DPERL_GCC_BRACE_GROUPS_FORBIDDEN but it
seems like that might end up impacting more than just this site,
according to the issue discussion above.
</quote>

Based-on-a-patch-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # Debian/Selfmade LLVM-14 (x86-64)
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Keeping <john@metanate.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Link: http://lore.kernel.org/lkml/YkxWcYzph5pC1EK8@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-04-09 12:34:16 -03:00
..
Documentation tools build: Add CFLAGS_REMOVE_* support 2016-11-14 11:37:25 -03:00
feature tools build: Filter out options and warnings not supported by clang 2022-04-09 12:34:16 -03:00
tests License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Build tools build: Make fixdep a hostprog 2016-10-03 11:40:35 -03:00
Build.include tools build: Enable warnings through HOSTCFLAGS 2021-12-07 22:18:23 -03:00
fixdep.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile kbuild: replace $(if A,A,B) with $(or A,B) 2022-02-15 12:25:56 +09:00
Makefile.build tools build: Fix quiet cmd indentation 2021-05-17 12:10:03 +09:00
Makefile.feature tools build: Remove needless libpython-version feature check that breaks test-all fast path 2021-12-06 21:57:53 -03:00
Makefile.include treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00