path: root/lib/CodeGen/CGCall.cpp

//===----- CGCall.h - Encapsulate calling convention details ----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// These classes wrap the information about a call or function
// definition used to handle ABI compliancy.
//
//===----------------------------------------------------------------------===//

#include "CGCall.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Attributes.h"
#include "llvm/Support/CommandLine.h"
using namespace clang;
using namespace CodeGen;

static llvm::cl::opt<bool>
UseX86_64ABI("use-x86_64-abi",
           llvm::cl::desc("Enable use of experimental x86_64 ABI."),
           llvm::cl::init(false));

/***/

// FIXME: Use iterator and sidestep silly type array creation.

CGFunctionInfo::CGFunctionInfo(const FunctionTypeNoProto *FTNP)
  : IsVariadic(true)
{
  ArgTypes.push_back(FTNP->getResultType());
}

CGFunctionInfo::CGFunctionInfo(const FunctionTypeProto *FTP)
  : IsVariadic(FTP->isVariadic())
{
  ArgTypes.push_back(FTP->getResultType());
  for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
    ArgTypes.push_back(FTP->getArgType(i));
}

// FIXME: Is there really any reason to have this still?
CGFunctionInfo::CGFunctionInfo(const FunctionDecl *FD)
{
  const FunctionType *FTy = FD->getType()->getAsFunctionType();
  const FunctionTypeProto *FTP = dyn_cast<FunctionTypeProto>(FTy);

  ArgTypes.push_back(FTy->getResultType());
  if (FTP) {
    IsVariadic = FTP->isVariadic();
    for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
      ArgTypes.push_back(FTP->getArgType(i));
  } else {
    IsVariadic = true;
  }
}

CGFunctionInfo::CGFunctionInfo(const ObjCMethodDecl *MD,
                               const ASTContext &Context)
  : IsVariadic(MD->isVariadic())
{
  ArgTypes.push_back(MD->getResultType());
  ArgTypes.push_back(MD->getSelfDecl()->getType());
  ArgTypes.push_back(Context.getObjCSelType());
  for (ObjCMethodDecl::param_const_iterator i = MD->param_begin(),
         e = MD->param_end(); i != e; ++i)
    ArgTypes.push_back((*i)->getType());
}

ArgTypeIterator CGFunctionInfo::argtypes_begin() const {
  return ArgTypes.begin();
}

ArgTypeIterator CGFunctionInfo::argtypes_end() const {
  return ArgTypes.end();
}

/***/

CGCallInfo::CGCallInfo(QualType _ResultType, const CallArgList &_Args) {
  ArgTypes.push_back(_ResultType);
  for (CallArgList::const_iterator i = _Args.begin(), e = _Args.end(); i!=e; ++i)
    ArgTypes.push_back(i->second);
}

ArgTypeIterator CGCallInfo::argtypes_begin() const {
  return ArgTypes.begin();
}

ArgTypeIterator CGCallInfo::argtypes_end() const {
  return ArgTypes.end();
}

/***/

/// ABIArgInfo - Helper class to encapsulate information about how a
/// specific C type should be passed to or returned from a function.
class ABIArgInfo {
public:
  enum Kind {
    Default,
    StructRet, /// Only valid for return values. The return value
               /// should be passed through a pointer to a caller
               /// allocated location passed as an implicit first
               /// argument to the function.

    Ignore,    /// Ignore the argument (treat as void). Useful for
               /// void and empty structs.

    Coerce,    /// Only valid for aggregate return types, the argument
               /// should be accessed by coercion to a provided type.

    ByVal,     /// Only valid for aggregate argument types. The
               /// structure should be passed "byval" with the
               /// specified alignment (0 indicates default
               /// alignment).

    Expand,    /// Only valid for aggregate argument types. The
               /// structure should be expanded into consecutive
               /// arguments for its constituent fields. Currently
               /// expand is only allowed on structures whose fields
               /// are all scalar types or are themselves expandable
               /// types.

    KindFirst=Default, KindLast=Expand
  };

private