[cfe-dev] merging of FunctionDecl's

[Roman Divacky]

Hi,

example code:

int func(void);					(1)
extern int func (void) __asm__ ("FUNC");	(2)

int func(void) {
      return 42;
}


this piece of code has two declarators (1 and 2). When clang decides
what symbol name the code goes like this:

CodeGenModule::GetAddrOfFunction

	return GetOrCreateLLVMFunction(getMangledName(GD), Ty, GD);


the getMangledName() calls

	if (!mangleName(getMangleContext(), ND, Out)) {

which creates CXXNameMangler and tries to mangle the name via it:

    CXXNameMangler Mangler(Context, os);
    if (!Mangler.mangle(cast<NamedDecl>(D->getCanonicalDecl())))
      return false;

the CXXNameMangler::mangle() looks at __asm__(name) and uses it if available

  if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
    // If we have an asm name, then we use it as the mangling.
    Out << '\01';  // LLVM IR Marker for __asm("foo")
    Out << ALA->getLabel();
    return true;
  }

the problem is that when emitting function via CodeGenModule::EmitGlobalFunctionDefinition()
only the first FunctionDecl is used. ie. if  (1) is first it will ommit
the needed __asm__ name mangling because (1) does not have any AsmLabelAttr assigned.

What is the correct solution for this? What should be done so the (2) has precedence
over (1) ?


thnx! roman