[Valgrind-developers] Re: [Patch] Dwarf2 debug info...

[Julian S. <js...@ac...>]

Thanks Josef, that's very excellent.  I had heard many bug reports
saying that the DWARF2 reader does not work very well, and so it seems
like this fixes it.  I will try and get it in a release soon.  If you make
any more bug fixes to this reader, please let me know ASAP.

J


On Friday 11 October 2002 10:33 pm, Josef Weidendorfer wrote:
> Hi,
>
> I recently updated to Suse8.1 with GCC 3.2 and had a lot
> of problems with cachegrind regarding DWARF2 debug info.
>
> Attached patch is for the Dwarf2 source line info reader;
> For reading, a state machine is used reconstructing source line
> info while running and reading (see DWARF2 specification, ch. 6.2).
> The state machine was correct, but the calls to addLineInfo()
> were wrong: It reported most of the times too small ranges
> for source code statements, because it used only the diff of the last
> state machine command instead of the diff to the last statement
> boundary. Effect: Around 1/3 of all addresses with source line info got
> unknown location.
> The patch adds a "last_address" to the state machine to remember the last
> statement boundary. On reset, it#s initialised to the "invalid" address 0.
> I hope this is OK (or should we use "(Addr)-1" instead?).
> The patch now uses the "is_stmt" boolean correctly to only call
> addLineInfo() if there's a statement boundary (on x86, is_stmt most
> probably is
> always true...).
>
> Please apply both to 1.0.x branch and HEAD.
>
> Another problem:
> Symbols like "_GLOBAL__I__ZNK10DirTreeMap9classNameEv" aren't demangled.
> I need to look at this...
>
> Josef