[llvm-commits] [llvm-gcc-4.2] r93387 - /llvm-gcc-4.2/trunk/gcc/omp-low.c

[Duncan Sands]

Hi Stuart,

>> why?  Where are you going with these patches?
> 
> I'm supposed to teach llvm-gcc how to emit lexical blocks into DWARF.  
> I've been testing with the GCC DejaGNU test suite, and my lexical-block 
> emitter has uncovered many latent bugs, all on the GCC side.

thanks for the explanation.

> I don't know much about your Dragon's Egg (did I spell that correctly?) 
> project, but I wonder if the lexical block emitter might pose a problem 
> for it.  GCC hasn't been perfectly disciplined about lexical blocks, 
> compensating with searching techniques in the tree/RTL interface.  (If a 
> tree is missing its lexical block decoration, GCC will use a binary 
> search to identify the most probable lexical block when generating 
> RTL.)  The existing (and reasonable!) LLVM ABI does not afford me that 
> luxury, thus I've been fixing GCC.   BTW, I think clang is already 
> generating correct lexical block info.

There have been big changes in how GCC represents debug info in gcc-4.5,
due to the need to be able to stream out effective debug info along with
the gimple when doing link-time-optimization.  So I wouldn't worry about
dragonegg (which uses gcc-4.5), because probably things will have to be
done differently there anyway.

Ciao,

Duncan.