[PATCH] D21489: [codeview] Added support for bitfield type

[David Majnemer via llvm-commits]

majnemer added a comment.

In http://reviews.llvm.org/D21489#463372, @aaboud wrote:

> In http://reviews.llvm.org/D21489#462178, @majnemer wrote:
>
> > This approach still seems a little problematic, consider:
> >
> >   #pragma pack(1)
> >   struct S {
> >     char  : 0;
> >     int y : 1;
> >   };
> >   S s;
> >
> >
> > Your code will produce:
> >
> >   BitField (0x1001) {
> >     TypeLeafKind: LF_BITFIELD (0x1205)
> >     Type: int (0x74)
> >     BitSize: 1
> >     BitOffset: 8
> >   }
> >   UnknownLeaf (0x1002) {
> >     TypeLeafKind: LF_FIELDLIST (0x1203)
> >     DataMember {
> >       AccessSpecifier: Public (0x3)
> >       Type: 0x1001
> >       FieldOffset: 0x0
> >       Name: y
> >     }
> >   }
> >   
> >
> > However, I think it should produce:
> >
> >   BitField (0x1001) {
> >     TypeLeafKind: LF_BITFIELD (0x1205)
> >     Type: int (0x74)
> >     BitSize: 1
> >     BitOffset: 0
> >   }
> >   UnknownLeaf (0x1002) {
> >     TypeLeafKind: LF_FIELDLIST (0x1203)
> >     DataMember {
> >       AccessSpecifier: Public (0x3)
> >       Type: 0x1001
> >       FieldOffset: 0x1
> >       Name: y
> >     }
> >   }
> >   
> >
> > I'm pretty sure that the only real way to get bitfields right is by encoding the storage offset in the DI metadata.
>
>
> I think my code will produce:
>
>   BitField (0x1001) {
>     TypeLeafKind: LF_BITFIELD (0x1205)
>     Type: int (0x74)
>     BitSize: 1
>     BitOffset: 0
>   }
>   UnknownLeaf (0x1002) {
>     TypeLeafKind: LF_FIELDLIST (0x1203)
>     DataMember {
>       AccessSpecifier: Public (0x3)
>       Type: 0x1001
>       FieldOffset: 0x0
>       Name: y
>     }
>   }
>
>
> Which is the same as MS cl.


Would you mind adding it as a test case? Also, can you please rebase your patch?  I cannot seem to apply it to trunk.


http://reviews.llvm.org/D21489