vg_leak issues

[Tim Northover]

>> +unsigned ARMFastISel::getLibcallReg(const Twine &Name) {
>> +  GlobalValue *GV = new GlobalVariable(Type::getInt32Ty(*Context), false,
>> +                                       GlobalValue::ExternalLinkage, 0, Name);
>> +  return ARMMaterializeGV(GV, TLI.getValueType(GV->getType()));
>>  }
>>
>> GV leaks.
>
> This is a particularly nasty one. During codegen the IR module is
> constant, so we cannot add to it. It looks like what is needed is for
> MI to have a way to represent a variable without creating an IR level
> one.

Isn't that what ExternalSymbol is for? Though dealing with both of
those cases is rather annoying, you frequently have to duplicate code
because a global is almost, but not quite, identical to an external.

Tim.