linux/tools/perf/scripts/perl/Perf-Trace-Util
Leo Yan e7e86d7697 perf build: Disable thread safety analysis for perl header
When build with perl5, it reports error:

    In file included from /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7933:
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/inline.h:298:5: error:
          mutex 'PL_env_mutex.lock' is not held on every path through
          here [-Werror,-Wthread-safety-analysis]
      298 |     ENV_UNLOCK;
          |     ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7091:31: note:
          expanded from macro 'ENV_UNLOCK'
     7091 | #  define ENV_UNLOCK          PERL_REENTRANT_UNLOCK("env"...
          |                               ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:6465:7: note:
          expanded from macro 'PERL_REENTRANT_UNLOCK'
     6465 |     } STMT_END
          |       ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:865:28: note:
          expanded from macro 'STMT_END'
      865 | #   define STMT_END     while (0)
          |                                ^

The error is caused by perl header but not perf code, disable thread
safety analysis if including the header.

Though GCC does not support the thread safety analysis option, this
negative warning flag is silently ignored by it.

Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-4-4305590795b2@arm.com
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-10-06 16:49:25 -03:00
..
lib/Perf/Trace
Build perf build: Disable thread safety analysis for perl header 2025-10-06 16:49:25 -03:00
Context.c
Context.xs
Makefile.PL
README
typemap

README

Perf-Trace-Util version 0.01
============================

This module contains utility functions for use with perf script.

Core.pm and Util.pm are pure Perl modules; Core.pm contains routines
that the core perf support for Perl calls on and should always be
'used', while Util.pm contains useful but optional utility functions
that scripts may want to use.  Context.pm contains the Perl->C
interface that allows scripts to access data in the embedding perf
executable; scripts wishing to do that should 'use Context.pm'.

The Perl->C perf interface is completely driven by Context.xs.  If you
want to add new Perl functions that end up accessing C data in the
perf executable, you add desciptions of the new functions here.
scripting_context is a pointer to the perf data in the perf executable
that you want to access - it's passed as the second parameter,
$context, to all handler functions.

After you do that:

  perl Makefile.PL   # to create a Makefile for the next step
  make               # to create Context.c

  edit Context.c to add const to the char* file = __FILE__ line in
  XS(boot_Perf__Trace__Context) to silence a warning/error.

  You can delete the Makefile, object files and anything else that was
  generated e.g. blib and shared library, etc, except for of course
  Context.c

  You should then be able to run the normal perf make as usual.

INSTALLATION

Building perf with perf script Perl scripting should install this
module in the right place.

You should make sure libperl and ExtUtils/Embed.pm are installed first
e.g. apt-get install libperl-dev or yum install perl-ExtUtils-Embed.

DEPENDENCIES

This module requires these other modules and libraries:

  None

COPYRIGHT AND LICENCE

Copyright (C) 2009 by Tom Zanussi <tzanussi@gmail.com>

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.10.0 or,
at your option, any later version of Perl 5 you may have available.

Alternatively, this software may be distributed under the terms of the
GNU General Public License ("GPL") version 2 as published by the Free
Software Foundation.