path: root/lib/CodeGen/CodeGenModule.cpp

//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This coordinates the per-module state used while generating code.
//
//===----------------------------------------------------------------------===//

#include "CGDebugInfo.h"
#include "CodeGenModule.h"
#include "CodeGenFunction.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Intrinsics.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Analysis/Verifier.h"
#include <algorithm>
using namespace clang;
using namespace CodeGen;


CodeGenModule::CodeGenModule(ASTContext &C, const LangOptions &LO,
                             llvm::Module &M, const llvm::TargetData &TD,
                             Diagnostic &diags, bool GenerateDebugInfo)
  : Context(C), Features(LO), TheModule(M), TheTargetData(TD), Diags(diags),
    Types(C, M, TD), MemCpyFn(0), MemMoveFn(0), MemSetFn(0),
    CFConstantStringClassRef(0) {
  //TODO: Make this selectable at runtime
  Runtime = CreateObjCRuntime(*this);

  // If debug info generation is enabled, create the CGDebugInfo object.
  if (GenerateDebugInfo)
    DebugInfo = new CGDebugInfo(this);
  else
    DebugInfo = NULL;
}

CodeGenModule::~CodeGenModule() {
  EmitStatics();
  llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction();
  if (ObjCInitFunction)
    AddGlobalCtor(ObjCInitFunction);
  EmitGlobalCtors();
  EmitAnnotations();
  delete Runtime;
  delete DebugInfo;
  // Run the verifier to check that the generated code is consistent.
  assert(!verifyModule(TheModule));
}

/// WarnUnsupported - Print out a warning that codegen doesn't support the
/// specified stmt yet.
void CodeGenModule::WarnUnsupported(const Stmt *S, const char *Type) {
  unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Warning, 
                                               "cannot codegen this %0 yet");
  SourceRange Range = S->getSourceRange();
  std::string Msg = Type;
  getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID,
                    &Msg, 1, &Range, 1);
}

/// WarnUnsupported - Print out a warning that codegen doesn't support the
/// specified decl yet.
void CodeGenModule::WarnUnsupported(const Decl *D, const char *Type) {
  unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Warning, 
                                               "cannot codegen this %0 yet");
  std::string Msg = Type;
  getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID,
                    &Msg, 1);
}

/// setVisibility - Set the visibility for the given LLVM GlobalValue
/// according to the given clang AST visibility value.
void CodeGenModule::setVisibility(llvm::GlobalValue *GV,
                                  VisibilityAttr::VisibilityTypes Vis) {
  switch (Vis) {
  default: assert(0 && "Unknown visibility!");
  case VisibilityAttr::DefaultVisibility:
    GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
    break;
  case VisibilityAttr::HiddenVisibility:
    GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
    break;
  case VisibilityAttr::ProtectedVisibility:
    GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
    break;
  }
}

/// AddGlobalCtor - Add a function to the list that will be called before
/// main() runs.
void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor) {
  // TODO: Type coercion of void()* types.
  GlobalCtors.push_back(Ctor);
}

/// EmitGlobalCtors - Generates the array of contsturctor functions to be
/// called on module load, if any have been registered with AddGlobalCtor.
void CodeGenModule::EmitGlobalCtors() {
  if (GlobalCtors.empty()) return;
  
  // Get the type of @llvm.global_ctors
  std::vector<const llvm::Type*> CtorFields;
  CtorFields.push_back(llvm::IntegerType::get(32));
  // Constructor function type
  std::vector<const llvm::Type*> VoidArgs;
  llvm::FunctionType* CtorFuncTy =
    llvm::FunctionType::get(llvm::Type::VoidTy, VoidArgs, false);
  
  // i32, function type pair
  const llvm::Type *FPType = llvm::PointerType::getUnqual(CtorFuncTy);
  llvm::StructType* CtorStructTy = 
  llvm::StructType::get(llvm::Type::Int32Ty, FPType, NULL);
  // Array of fields
  llvm::ArrayType* GlobalCtorsTy = 
    llvm::ArrayType::get(CtorStructTy, GlobalCtors.size());
  
  // Define the global variable
  llvm::GlobalVariable *GlobalCtorsVal =
    new llvm::GlobalVariable(GlobalCtorsTy, false,
                             llvm::GlobalValue::AppendingLinkage,
                             (llvm::Constant*)0, </