[LLVMdev] Clang's approach to anonymous struct pointer parameters

[Florian Brandner]

Hi Rick,

this is a bug in Clang's LLVM-IR code generator:
http://llvm.org/bugs/show_bug.cgi?id=14920

Best,
Florian

On Sunday, January 20, 2013 01:57:37 Rick Mann wrote:
> For the following code:
> 
>     struct XBeePacket;
>     
>     typedef void (*CompletionProc)(XBeePacket* inPacket, void* inParam2);
>     
>     struct
>     XBeePacket
>     {
>         bool            mField1;
>         CompletionProc  mCompletionProc;
>     };
> 
> Why does clang emit this IR?
> 
>     %struct.XBeePacket = type { i8, {}* }
>     
>     define void
>     @MyCompletionProc(%struct.XBeePacket* %inPacket, i8* %inParam2)
>         nounwind uwtable ssp
>     {
>     entry:
>       ...
>     }
> 
> It makes the struct field for the completion proc an an anonymous aggregate pointer. Is that better than making the first parameter to MyCompletionProc void* or something similar?
> 
> I guess there's no way in LLVM IR to forward-declare in a way that solves this, huh?
> 
> 
-- 
Florian Brandner
Embedded Systems Engineering Group
Department of Applied Mathematics and Computer Science
Technical University of Denmark
Richard Petersens Plads
Building 322, room 206
2800 Lyngby
Denmark

phone: +45 45255223
web: http://www.imm.dtu.dk/~flbr/
email: flbr at imm.dtu.dk