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|
//===--- 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 "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/TargetInfo.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Intrinsics.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)
: Context(C), Features(LO), TheModule(M), TheTargetData(TD), Diags(diags),
Types(C, M, TD), MemCpyFn(0), MemSetFn(0), CFConstantStringClassRef(0) {
//TODO: Make this selectable at runtime
Runtime = CreateObjCRuntime(M,
getTypes().ConvertType(getContext().IntTy),
getTypes().ConvertType(getContext().LongTy));
}
CodeGenModule::~CodeGenModule() {
llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction();
if (ObjCInitFunction) {
AddGlobalCtor(ObjCInitFunction);
}
EmitGlobalCtors();
delete Runtime;
}
/// 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);
}
/// 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, "llvm.global_ctors",
&TheModule);
// Populate the array
std::vector<llvm::Constant*> CtorValues;
llvm::Constant *MagicNumber =
llvm::ConstantInt::get(llvm::Type::Int32Ty, 65535, false);
std::vector<llvm::Constant*> StructValues;
for (std::vector<llvm::Constant*>::iterator I = GlobalCtors.begin(),
E = GlobalCtors.end(); I != E; ++I) {
StructValues.clear();
StructValues.push_back(MagicNumber);
StructValues.push_back(*I);
CtorValues.push_back(llvm::ConstantStruct::get(CtorStructTy, StructValues));
}
GlobalCtorsVal->setInitializer(llvm::ConstantArray::get(GlobalCtorsTy,
CtorValues));
}
/// ReplaceMapValuesWith - This is a really slow and bad function that
/// searches for any entries in GlobalDeclMap that point to OldVal, changing
/// them to point to NewVal. This is badbadbad, FIXME!
void CodeGenModule::ReplaceMapValuesWith(llvm::Constant *OldVal,
llvm::Constant *NewVal) {
for (llvm::DenseMap<const Decl*, llvm::Constant*>::iterator
I = GlobalDeclMap.begin(), E = GlobalDeclMap.end(); I != E; ++I)
if (I->second == OldVal) I->second = NewVal;
}
llvm::Constant *CodeGenModule::GetAddrOfFunctionDecl(const FunctionDecl *D,
bool isDefinition) {
// See if it is already in the map. If so, just return it.
llvm::Constant *&Entry = GlobalDeclMap[D];
if (Entry) return Entry;
const llvm::Type *Ty = getTypes().ConvertType(D->getType());
// Check to see if the function already exists.
llvm::Function *F = getModule().getFunction(D->getName());
const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
// If it doesn't already exist, just create and return an entry.
if (F == 0) {
// FIXME: param attributes for sext/zext etc.
F = new llvm::Function(FTy, llvm::Function::ExternalLinkage, D->getName(),
&getModule());
// Set the appropriate calling convention for the Function.
if (D->getAttr<FastCallAttr>())
F->setCallingConv(llvm::CallingConv::Fast);
return Entry = F;
}
// If the pointer type matches, just return it.
llvm::Type *PFTy = llvm::PointerType::getUnqual(Ty);
if (PFTy == F->getType()) return Entry = F;
// If this isn't a definition, just return it casted to the right type.
if (!isDefinition)
return Entry = llvm::ConstantExpr::getBitCast(F, PFTy);
// Otherwise, we have a definition after a prototype with the wrong type.
// F is the Function* for the one with the wrong type, we must make a new
// Function* and update everything that used F (a declaration) with the new
// Function* (which will be a definition).
//
// This happens if there is a prototype for a function (e.g. "int f()") and
// then a definition of a different type (e.g. "int f(int x)"). Start by
// making a new function of the correct type, RAUW, then steal the name.
llvm::Function *NewFn = new llvm::Function(FTy,
llvm::Function::ExternalLinkage,
"", &getModule());
NewFn->takeName(F);
// Replace uses of F with the Function we will endow with a body.
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(NewFn, F->getType());
F->replaceAllUsesWith(NewPtrForOldDecl);
// FIXME: Update the globaldeclmap for the previous decl of this name. We
// really want a way to walk all of these, but we don't have it yet. This
// is incredibly slow!
ReplaceMapValuesWith(F, NewPtrForOldDecl);
// Ok, delete the old function now, which is dead.
assert(F->isDeclaration() && "Shouldn't replace non-declaration");
F->eraseFromParent();
// Return the new function which has the right type.
return Entry = NewFn;
}
static bool IsZeroElementArray(const llvm::Type *Ty) {
if (const llvm::ArrayType *ATy =
|