Re: [PATCH] perf: perl: force to use stdbool.

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Jan 19, 2015 at 07:51:54PM +0800, Wang Nan wrote:
> On 2015/1/19 19:23, Jiri Olsa wrote:
> > On Mon, Jan 19, 2015 at 06:42:17PM +0800, Wang Nan wrote:
> >> Add Jiri Olsa jolsa@kernel.org to CC list. I think jolsa@kernel.org should be the main
> >> email address he uses.
> > 
> > ack ;-)
> > 
> > jirka
> > 
> >>
> >> On 2015/1/15 13:55, Wang Nan wrote:
> >>> When building perf for arm64 I hit a warning (and be treated as an
> >>> error) like below:
> >>>
> >>>  aarch64-oe-linux-gcc -o .../util/scripting-engines/trace-event-python.o -c -Wbad-function-cast \
> >>> 	 ... util/scripting-engines/trace-event-python.c
> >>>
> >>>  In file included from .../usr/lib64/perl/5.14.3/CORE/perl.h:2464:0,
> >>>                   from Context.xs:23:
> >>>  /.../usr/lib64/perl/5.14.3/CORE/handy.h:108:0: error: "bool" redefined [-Werror]
> >>>   #  define bool char
> >>>   ^
> >>>  In file included from /.../usr/src/kernel/tools/include/linux/types.h:4:0,
> >>>                   from /.../usr/src/kernel/arch/arm64/include/uapi/asm/sigcontext.h:19,
> >>> 		  from /.../usr/include/bits/sigcontext.h:27,
> >>> 		  from /.../usr/include/signal.h:340,
> >>> 		  from /.../usr/include/sys/param.h:28,
> >>> 		  from /.../usr/lib64/perl/5.14.3/CORE/perl.h:678,
> >>> 		  from Context.xs:23:
> >>>   /.../usr/lib/aarch64-oe-linux/gcc/aarch64-oe-linux/4.9.2/include/stdbool.h:33:0: note: this is the location of the previous definition
> >>>     #define bool _Bool
> >>>
> >>> Looks like the failure is caused by arm64 uapi/asm/sigcontext.h, which
> >>> includes linux/types.h while other archs not.
> >>>
> >>> This patch includes stdbool.h before Context.xs and define HAS_BOOL to
> >>> prevent perl'e headers define its own 'bool'.
> >>>
> >>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> >>> ---
> >>>  tools/perf/scripts/perl/Perf-Trace-Util/Context.c | 3 ++-
> >>>  1 file changed, 2 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/tools/perf/scripts/perl/Perf-Trace-Util/Context.c b/tools/perf/scripts/perl/Perf-Trace-Util/Context.c
> >>> index 790ceba..69c3572 100644
> >>> --- a/tools/perf/scripts/perl/Perf-Trace-Util/Context.c
> >>> +++ b/tools/perf/scripts/perl/Perf-Trace-Util/Context.c
> >>> @@ -5,7 +5,8 @@
> >>>   *	ANY CHANGES MADE HERE WILL BE LOST! 
> >>>   *
> >>>   */
> >>> -
> >>> +#include <stdbool.h>
> >>> +#define HAS_BOOL 1
> > 
> > I saw this patch before.. but I had no idea ;-)
> > 
> > seems hacky to me? Is there any doc saying 'this is how you handle this with perl' ? ;-)
> > 
> 
> It is hacky. I'm not very familiar with perl, I just try to build it.
> 
> I checked perl's repository and found that newest perl does consider this problem:
> 
> http://perl5.git.perl.org/perl.git/commit/bd31be4baa3ee68abdb92c0db3200efe0fad903b
> 
> So the root cause is in my perl version.
> 
> What's your policy then? Do you think we should provid a workaround or just force
> users update their perl?

I guess thats ok then.. maybe use it the way they did:

#include <stdbool.h>
#ifndef HAS_BOOL
#  define HAS_BOOL 1
#endif

not sure if the better fix would be regenerating Context.c somehow,
as it indicates it's been generated ;-)

but if nobody screams, I'm ok with this..

jirka