lib/Target/X86/X86COFFMachineModuleInfo.cpp

//===-- llvm/CodeGen/X86COFFMachineModuleInfo.cpp -------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This is an MMI implementation for X86 COFF (windows) targets.
//
//===----------------------------------------------------------------------===//

#include "X86COFFMachineModuleInfo.h"
#include "X86MachineFunctionInfo.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetData.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;


X86COFFMachineModuleInfo::~X86COFFMachineModuleInfo() {
}

/// DecorateCygMingName - Query FunctionInfoMap and use this information for
/// various name decorations for Cygwin and MingW.
void X86COFFMachineModuleInfo::DecorateCygMingName(MCSymbol *&NameSym,
                                                   MCContext &Ctx,
                                                   const Function *F,
                                                   const TargetData &TD) {
  SmallString<128> Name(NameSym->getName().begin(), NameSym->getName().end());
  
  // We don't want to decorate non-stdcall or non-fastcall functions right now
  CallingConv::ID CC = F->getCallingConv();
  if (CC != CallingConv::X86_StdCall && CC != CallingConv::X86_FastCall)
    return;
  
  unsigned ArgWords = 0;
  
  // Calculate arguments sizes
  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
       AI != AE; ++AI) {
    const Type *Ty = AI->getType();
    
    // 'Dereference' type in case of byval parameter attribute
    if (AI->hasByValAttr())
      Ty = cast<PointerType>(Ty)->getElementType();
    
    // Size should be aligned to DWORD boundary
    ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4;
  }
  
  const FunctionType *FT = F->getFunctionType();
  // "Pure" variadic functions do not receive @0 suffix.
  if (!FT->isVarArg() || FT->getNumParams() == 0 ||
      (FT->getNumParams() == 1 && F->hasStructRetAttr()))
    raw_svector_ostream(Name) << '@' << ArgWords;
  
  if (CC == CallingConv::X86_FastCall) {
    if (Name[0] == '_')
      Name[0] = '@';
    else
      Name.insert(Name.begin(), '@');
  }
  
  NameSym = Ctx.GetOrCreateSymbol(Name.str());
}