Re: [PATCH] perf: fix building warning on ARM 32.

[Wang Nan <wangnan0@huawei.com>]

On 2014/12/16 12:49, Namhyung Kim wrote:
> Hi Wang,
> 
> On Tue, Dec 16, 2014 at 10:10:10AM +0800, Wang Nan wrote:
>> Commit 85c116a6c introduces asprintf() call and matches '%ld' to a u64
>> argument, which is incorrect on ARM.
>>
>>    CC       /home/wn/util/srcline.o
>>  util/srcline.c: In function 'get_srcline':
>>  util/srcline.c:297:6: error: format '%ld' expects argument of type 'long int', but argument 4 has type 'u64' [-Werror=format]
>>  cc1: all warnings being treated as errors
>>  make[1]: *** [/home/wn/util/srcline.o] Error 1
> 
> Hmm.. shouldn't it be %PRIu64 instead?
> 

It is a difference between two addresses, and I believe the value should not be very large.

Anyway, I'll follow your advise if you prefer to use %PRIu64.

In addition, addr is 'unsigned long addr', sym->start is 'u64', the type if
this expression is more or less obscure to readers. By investigating all caller
of get_srcline(), I find that the type of 'addr' should be 'u64', not 'unsigned long'.
So I'll post another patch which fixes param list of get_srcline() also.

Thanks.

> Thanks,
> Namhyung
> 
> 
>>
>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
>> ---
>>  tools/perf/util/srcline.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
>> index e73b6a5..42cb642 100644
>> --- a/tools/perf/util/srcline.c
>> +++ b/tools/perf/util/srcline.c
>> @@ -294,7 +294,7 @@ out:
>>  	}
>>  	if (sym) {
>>  		if (asprintf(&srcline, "%s+%ld", show_sym ? sym->name : "",
>> -					addr - sym->start) < 0)
>> +					(long int)(addr - sym->start)) < 0)
>>  			return SRCLINE_UNKNOWN;
>>  	} else if (asprintf(&srcline, "%s[%lx]", dso->short_name, addr) < 0)
>>  		return SRCLINE_UNKNOWN;
>> -- 
>> 1.8.4
>>
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