[LLVMdev] More DIFactory questions - still stumped

[Talin]

On Tue, Sep 7, 2010 at 1:56 AM, Renato Golin <rengolin at systemcall.org>wrote:

> On 6 September 2010 01:05, Talin <viridia at gmail.com> wrote:
> > DISubprogram CodeGenerator::genDISubprogram(const FunctionDefn * fn,
> (...)
> >         false /* isDefinition */,
> (...)
>
> Hi Talin,
>
> The only difference from what I'm doing is that I only export debug
> symbols in definitions, not declarations. I may be doing wrong,
> though, for multi-file compilation (haven't tested thoroughly).
>
>
>
> > DICompositeType CodeGenerator::genDIFunctionType(const FunctionType *
> type)
> (...)
> >   for (ParameterList::const_iterator it = params.begin(); it !=
> > params.end(); ++it) {
> >     const ParameterDefn * param = *it;
> >     args.push_back(genDIParameterType(param->type()));
> >   }
>
> Don't do that. I know it looks right, but it's broken in DIFactory.
>
>
> >   DICompositeType fnType = dbgFactory_.CreateCompositeType(
> >       dwarf::DW_TAG_subroutine_type,
> >       dbgCompileUnit_,
>
> I use the file here, not the compile unit... But again, I could be wrong.
>
> Hope that puts you in the right direction.
>

OK I made 3 changes:
-- changed isDefinition to true. (I'm also only generating debug info for
definitions.)
-- commented out the code that pushes parameter types to the arg list.
(Still push the return type however.)
-- changed the call that creates the subroutine type to use DIFile rather
than DICompileUnit as the context param.

It still segfaults however. :(

I should mention that I don't actually know if the CreateSubprogram call is
even related to the problem. I know that when I comment out the call, the
segfault goes away - however, that just might mean that the problem is still
there but is not being triggered.

I have to admit I am rather confused about the proper usage of DIFile and
DICompileUnit. Both of these are DIScopes, but it's not clear to me whether
the symbols within a module should be the children of one or the other. Many
of the DIFactory parameters take an explicit DIFile, so those cases are
clear - but many of the other context params only have DIDescriptor as their
type, so there's not a lot of guidance as to which is the right type of
DIDescriptor to use.

>
> --
> cheers,
> --renato
>
> http://systemcall.org/
>
> Reclaim your digital rights, eliminate DRM, learn more at
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>



-- 
-- Talin
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