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

[Wang Nan <wangnan0@huawei.com>]

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?

Thank you.

> I couldn't find any.. or more detailed explanation why we should
> define HAS_BOOL and not perl headers..
> 
> thanks,
> jirka
>