[cfe-dev] [PATCH] Another patch for unnamed structure/union fields
pdherbemont at free.fr
Sat Nov 15 16:31:35 CST 2008
On Nov 15, 2008, at 8:41 PM, Patrick Walton wrote:
> I see that Pierre d'Herbemont has created a patch for unnamed inner
> records. At the same time I've been working on one as well. I'd like
> to submit it here too, at the suggestion of Eli Friedman.
> This patch causes clang to add extra MemberExpr nodes to the AST
> when fields of inner unnamed records are accessed. I first tried to
> implement the necessary logic in CodeGen, but this proved to be
> overly complex: the code generator is really welded to the idea that
> each MemberExpr denotes a single GEP instruction in either a single
> struct or a single union. In my proposed patch, the Sema module
> expands access to an inner field into the correct number of
> MemberExpr nodes at AST construction time. This approach essentially
> treats unnamed structs and unions as syntactic sugar, which seems
> valid to me.
Well, seems like a way cleaner way to go that what I tried to achieve...
> The CodePrinter logic is modified to deal with this. I've tested
> code generation on x86_64 and through lli, and it seems to work.
> Pierre's patch selectively turns on the extension only when -
> std=gnu99 is specified. This is a good idea IMO, which I hadn't
> thought of. So I would suggest that our two patches be merged,
> because mine adds the code generation, while his has better parsing
Well, I'll try to rebase my work on yours. I think that I should port
the conflicts between unnamed members check, along with the changes
that allow the clang test suite to pass...
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