Re: correct place for code.

[IainS <developer at sandoe-acoustics dot co dot uk>]

On 15 Jan 2009, at 01:44, Ian Lance Taylor wrote:
> > I need to make a test expanded from ASM_OUTPUT_LABEL_REF that is
> > language dependent (on objc/objcxx).
> It's pretty hard to think of any reason why something as low-level as
> ASM_OUTPUT_LABEL_REF would want to look at anything in the frontend.
> You are probably working at the wrong level.

I'm entirely prepared to believe that...

The problem is this (on darwin):
(currently) ASM_OUTPUT_LABELREF modifies the generated label in  
certain cases (where the symbols are internal to OBJC)
When these symbols are mangled in obj-c++ it makes it a much more  
difficult to detect them reliably.
"knowing" that the symbols have been mangled improves that.

Without the change to the label name we get wrong generated code  
which causes a ld fail (responsible for a fair number of the 'new  
rash' of obj-c++ testsuite fails on darwin9)

So options:

1/ Do something target-specific in the generation of the labels and  
their subsequent mangling...
   maybe this is the Right Way ...
  However, I don't know my way around well enough to know how hard  
that would be - and it does seem quite intrusive.

2/ assume that no sensible user will make an intention external  
symbol named ZLnnnn_OBJC_xxxxxx
   perhaps that's not too unreasonable... OBJC_xxxxx are effectively  
reserved identifiers - so perhaps mangled file scope variants of  
those could be too.

3/ tell the backend that the names have been mangled
   the idea here was to generalize the c_language enum to a  
"gcc_language" enum and export it from each gcc language.

4/ some other way ...  any input is most appreciated,
Iain