[PATCH] D36993: [llvm-dwarfdump] Print type names in DW_AT_type DIEs

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added a comment.

In https://reviews.llvm.org/D36993#859034, @dblaikie wrote:

> In https://reviews.llvm.org/D36993#858768, @JDevlieghere wrote:
>
> > In https://reviews.llvm.org/D36993#858121, @dblaikie wrote:
> >
> > > In https://reviews.llvm.org/D36993#858093, @JDevlieghere wrote:
> > >
> > > > David, apologies for missing your e-mail. I really hate that it doesn't automatically show up in Phabricator! 🙁
> > > >
> > > > If the tag doesn't have a name attribute, everything will go through this function except: `DW_TAG_pointer_type`, `DW_TAG_ptr_to_member_type`, `DW_TAG_reference_type`, `DW_TAG_rvalue_reference_type`. The first part explains why `class` and `struct` don't show up. I prefer this approach because it's guaranteed to be robust. Every `DW_TAG_*_type` encountered without a name will have something meaningful printed.
> > > >
> > > > IIRC, the original switch had between 20 and 25 cases.
> > >
> > >
> > > I'm curious what those 20-25 cases were - do you have a copy/roughly describe their contents? Because while 'const' does print nicely, (& volatile would be similar) I'm not sure what the other 10 or so cases might be and whether that's a reasonable way to print them.
> >
> >
> > Here's the list of cases I had originally:
> >
> >   case DW_TAG_array_type:
> >   case DW_TAG_base_type:
> >   case DW_TAG_class_type:
> >   case DW_TAG_const_type:
> >   case DW_TAG_enumeration_type:
> >   case DW_TAG_file_type:
> >   case DW_TAG_interface_type:
> >   case DW_TAG_packed_type:
> >   case DW_TAG_pointer_type:
> >   case DW_TAG_ptr_to_member_type:
> >   case DW_TAG_reference_type:
> >   case DW_TAG_restrict_type:
> >   case DW_TAG_set_type:
> >   case DW_TAG_shared_type:
> >   case DW_TAG_string_type
> >   case DW_TAG_structure_type:
> >   case DW_TAG_subrange_type:
> >   case DW_TAG_subroutine_type:
> >   case DW_TAG_thrown_type:
> >   case DW_TAG_union_type:
> >   case DW_TAG_unspecified_type:
> >   case DW_TAG_volatile_type:
> >
>
>
> Ah, thanks!
>
> I feel like maybe this should be examined more closely (an example of how each of these would be printed would be ideal, though that might be a bit much) - for example I don't think it makes sense to print out subroutine types like "int subroutine" (rather than "int(float, double)", say) which I /think/ is how they might look based on the current code)


Generally agreed, but I think it might make sense to improve this in separate follow-on patches on a case-by-case basis. Getting the pretty-printing entirely right would mean that we would have to implement different pretty-printers for each DW_LANG_foo, since e.g., a C function type would have to be rendered very differently from the same DWARF type-representation in an. e.g., Swift or Fortran context. And even if we choose to always render types as C types it is unclear what to do with types such as DW_TAG_set_type.


Repository:
  rL LLVM

https://reviews.llvm.org/D36993