[llvm-commits] [PATCH]: Fix for DW_at_stmt_list offset

[Tobias Grosser]

On 08/26/2010 10:08 AM, Krister Wombell wrote:
> In the compilation unit DIE, DW_at_stmt_list is supposed to be an offset
> into the debug_line information where the line program for this compile
> unit begins.
>
> It needs to be a label so that a relocation is emitted and during final
> linking the offset is adjusted.  Without this all CUs contain offset 0
> (and only 1 of them will be correct)
>
> Mostly been able to debug an ELF program under gdb now.
>
> Krister

Hey Krister,

I tried your patch and it solved the issue that I was not even able to 
set break points at a specific line. With your patch this works nicely 
in gdb.

One thing I realized is that this patch needs the patch in
"[PATCH] fix debug_ranges for ELF targets". Furthermore the following 
change is in both patches. I suppose it should be part of the "fix 
debug_ranges" patch?

Index: lib/CodeGen/AsmPrinter/DwarfDebug.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfDebug.cpp	(revision 112155)
+++ lib/CodeGen/AsmPrinter/DwarfDebug.cpp	(working copy)
@@ -3119,9 +3120,8 @@
      case dwarf::DW_AT_ranges: {
        // DW_AT_range Value encodes offset in debug_range section.
        DIEInteger *V = cast<DIEInteger>(Values[i]);
-      Asm->EmitLabelOffsetDifference(DwarfDebugRangeSectionSym,
+      Asm->EmitLabelPlusOffset(DwarfDebugRangeSectionSym,
                                       V->getValue(),
-                                     DwarfDebugRangeSectionSym,
                                       4);
        break;
      }


@everybody: Could someone knowing DWARF review these patches. It is 
really nice to have usable debugging in gdb with programs consisting of 
more than one CU.

Cheers
Tobi