[cfe-dev] Custom calling conventions in C code

[Holger Schurig]

> I think it would be a great thing for compiler hackers to have
> a mechanism to access an arbitrary calling convention, but I
> also think it would be a disaster to expose this to end user
> code.

Maybe via attributes and macros.

#define _CC_WEIRD_EMBEDDED_COMPILER \
  __attribute__(("cc-call-randomly")) \
  __attribute__(("cc-indirect-accumulator-access")) \
  __attribute__(("cc-halt-instruction-after-every-jump"))

And then I write

void weird_function(void) __CC_WEIRD_EMBEDDED_COMPILER
{
    // ...
}


> The problem is that not all constructs are valid with 
> every calling convention, and if there is ever a large install
> base of code using "calling convention 19" in their C code,
> we'd have to support that forever.

Not with a scheme similar to the like above.

However, you'd need to support the specific attribute forever. 
Not sure if that is a win :-)