llvm dev - Jun 2010 - [LLVMdev] [patch] New feature: debug info for function memory ranges (-jit-emit-debug-function-range)

This new option will allow to output function information in the same 
format as addr2line from binutils emits:
...
0xABCDEF01 T function_name_is_here
...

This feature is useful to profile the code when it is run in JIT by 
external tools like valgrind and google-perftools.
For example, google-perftools runs addr2line on executable and uses the 
resulting file to resolve memory addresses to function names. In case of 
LLVM JIT the resulting from --jit-emit-debug-addr2line option 
addr2line-formatted file can be just appended to the original addr2line 
file to allow google-perftools to show created by JIT functions as well.

Thank you,
Yuri
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Please do not check this in yet.
I will post an updated patch.

Yuri

This new option (--jit-emit-debug-function-range) will allow to output 
function information for memory ranges that functions occupy in memory 
while they run in JIT. File format generated is like this:
...
0x5000000 0x5001000 function_name_is_here
...

This feature is useful for external tools like valgrind and 
google-perftools to profile the code when it is run in JIT. Particularly 
google-perftools will have a special option (--external_symbols) that 
will be able to import this file.

Note: to be useful this flag should be used with -disable-fp-elim to 
generate standard prologs.

Thank you,
Yuri

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Have you found http://llvm.org/docs/DebuggingJITedCode.html? The JIT
already has support for something like this for gdb's benefit.
Perftools and valgrind just don't know how to find it yet.

On Sat, Jun 19, 2010 at 2:03 PM, Yuri <yuri at rawbw.com>
wrote:
> This new option (--jit-emit-debug-function-range) will allow to output
> function information for memory ranges that functions occupy in memory
while
> they run in JIT. File format generated is like this:
> ...
> 0x5000000 0x5001000 function_name_is_here
> ...
>
> This feature is useful for external tools like valgrind and
google-perftools
> to profile the code when it is run in JIT. Particularly google-perftools
> will have a special option (--external_symbols) that will be able to import
> this file.
>
> Note: to be useful this flag should be used with -disable-fp-elim to
> generate standard prologs.
>
> Thank you,
> Yuri
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>

Here is the corresponding patch to google-perftools. Both patches create 
a nice perftools profile with all functions in JIT.

http://code.google.com/p/google-perftools/issues/detail?id=255

Yuri

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On 06/19/2010 14:03, Yuri wrote:
> This new option (--jit-emit-debug-function-range) will allow to output 
> function information for memory ranges that functions occupy in memory 
> while they run in JIT. File format generated is like this:
> ...
> 0x5000000 0x5001000 function_name_is_here
> ...
>
> This feature is useful for external tools like valgrind and 
> google-perftools to profile the code when it is run in JIT. 
> Particularly google-perftools will have a special option 
> (--external_symbols) that will be able to import this file.
>
> Note: to be useful this flag should be used with -disable-fp-elim to 
> generate standard prologs.
>
> Thank you,
> Yuri
Anybody can check this in?

Yuri