Re: [Valgrind-users] Error in callgrind ( ???:function )

[Josef W. <Jos...@gm...>]

Am 17.02.2015 um 21:22 schrieb Raul Garcia:
> I am a new user, I am doing a "hello world" test of Valgrind but i keep
> hitting this error:
> ...
> 2,709 *???*:getenv [/home/otro/arm_emulator/hello_x86]

The "???" are not really any errors, but a sign that for these functions,
valgrind could not locate debug information providing a source file name.

> This is the command that I used, as you can see I used -g and -O0
> options as suggested.
> 
> $ gcc -static -g -O0 hello.c -o hello_x86

getenv above is from glibc, and you seem not to have debug information
installed for the statically linkable glibc.
"-O0" or "-g" does not help here, because the issue is with an already
compiled library.
Does it work if you remove "-static"? I have no idea if Ubuntu provides
debug info for libc.a ...

> But when I try to see the analysis with callgrind I get:
> 
>     Ir
> --------------------------------------------------------------------------------
> 11,737  PROGRAM TOTALS
> 
> --------------------------------------------------------------------------------
>    Ir  file:function
> --------------------------------------------------------------------------------
> 2,709  ???:getenv [/home/otro/arm_emulator/hello_x86]
> 1,133  ???:_int_malloc [/home/otro/arm_emulator/hello_x86]
>   813  ???:intel_check_word [/home/otro/arm_emulator/hello_x86]
>   792  ???:malloc_consolidate [/home/otro/arm_emulator/hello_x86]
>   783  ???:_IO_file_overflow [/home/otro/arm_emulator/hello_x86]
>   555  ???:strncmp [/home/otro/arm_emulator/hello_x86]
>   435  ???:ptmalloc_init.part.7 [/home/otro/arm_emulator/hello_x86]
>   361  ???:(below main) [/home/otro/arm_emulator/hello_x86]
>   342  ???:_IO_default_xsputn [/home/otro/arm_emulator/hello_x86]
>   311  ???:_dl_init_paths [/home/otro/arm_emulator/hello_x86]
> 
> And I cant see the cost of the functions . What can be the problem? Some
> logs are attached, i hope they are helpful.

Self cost is there.
To see inclusive costs, you need to use "callgrind_annotate
--inclusive=yes ...".
And "--tree=both" shows a butterfly output of the call graph.

I would suggest do use kcachegrind/qcachegrind to visualize callgrind
results.

Josef