• Ingo Molnar's avatar
    perf tools: Work around strict aliasing related warnings · 65014ab3
    Ingo Molnar authored
    Older versions of GCC are rather stupid about strict aliasing:
    
      util/trace-event-parse.c: In function 'parse_cmdlines':
      util/trace-event-parse.c:93: warning: dereferencing type-punned pointer will break strict-aliasing rules
      util/trace-event-parse.c: In function 'parse_proc_kallsyms':
      util/trace-event-parse.c:155: warning: dereferencing type-punned pointer will break strict-aliasing rules
      util/trace-event-parse.c:157: warning: dereferencing type-punned pointer will break strict-aliasing rules
      util/trace-event-parse.c:158: warning: dereferencing type-punned pointer will break strict-aliasing rules
      util/trace-event-parse.c: In function 'parse_ftrace_printk':
      util/trace-event-parse.c:294: warning: dereferencing type-punned pointer will break strict-aliasing rules
      util/trace-event-parse.c:295: warning: dereferencing type-punned pointer will break strict-aliasing rules
      make: *** [util/trace-event-parse.o] Error 1
    
    Make it clear to GCC that we intend with those pointers, by passing
    them through via an explicit (void *) cast.
    
    We might want to add -fno-strict-aliasing as well, like the kernel
    itself does.
    
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    LKML-Reference: <new-submission>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    65014ab3
trace-event-info.c 10.6 KB