[LLVMdev] x86_stdcallcc and extra name mangling on Windows

[Duncan Sands]

Hi David,

> I'm currently working on getting our (LDC) compiler to run on
> Win32/MinGW, now that DW2-style EH is available for it. The D
> programming language has a feature equivalent to LLVM module level
> inline assembly, so we need to at least partly follow the x86 D
> calling convention (http://dlang.org/abi.html).
>
> Most notably, the ABI mandates that the callee cleans the stack. On
> the various Posixen, we use x86_stdcallcc as a basis and apply some
> rewrites at the IR level to make things work just well enough.
> However, on Windows targets this does not work because of the extra
> name mangling applied.
>
> My question: Is there an easy way of disabling the name-mangling part
> but keep the rest of the CC that I missed? Because I couldn't find
> anything to that regard, I threw together a quick patch to add a
> custom calling convention (see attachment). It seems to work for now,
> but is there a better solution?

if you use "\1" + "usual name", it will disable name mangling if you are
lucky.  A leading \1 is LLVM's way of saying: leave this name alone!

Ciao, Duncan.