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//===--- ModuleBuilder.cpp - Emit LLVM Code from ASTs ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This builds an AST and converts it to LLVM Code.
//
//===----------------------------------------------------------------------===//
#include "clang/CodeGen/ModuleBuilder.h"
#include "CGDebugInfo.h"
#include "CodeGenModule.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/Basic/CodeGenOptions.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include <memory>
using namespace clang;
using namespace CodeGen;
namespace {
class CodeGeneratorImpl : public CodeGenerator {
DiagnosticsEngine &Diags;
ASTContext *Ctx;
const HeaderSearchOptions &HeaderSearchOpts; // Only used for debug info.
const PreprocessorOptions &PreprocessorOpts; // Only used for debug info.
const CodeGenOptions CodeGenOpts; // Intentionally copied in.
unsigned HandlingTopLevelDecls;
/// Use this when emitting decls to block re-entrant decl emission. It will
/// emit all deferred decls on scope exit. Set EmitDeferred to false if decl
/// emission must be deferred longer, like at the end of a tag definition.
struct HandlingTopLevelDeclRAII {
CodeGeneratorImpl &Self;
bool EmitDeferred;
HandlingTopLevelDeclRAII(CodeGeneratorImpl &Self,
bool EmitDeferred = true)
: Self(Self), EmitDeferred(EmitDeferred) {
++Self.HandlingTopLevelDecls;
}
~HandlingTopLevelDeclRAII() {
unsigned Level = --Self.HandlingTopLevelDecls;
if (Level == 0 && EmitDeferred)
Self.EmitDeferredDecls();
}
};
CoverageSourceInfo *CoverageInfo;
protected:
std::unique_ptr<llvm::Module> M;
std::unique_ptr<CodeGen::CodeGenModule> Builder;
private:
SmallVector<FunctionDecl *, 8> DeferredInlineMemberFuncDefs;
static llvm::StringRef ExpandModuleName(llvm::StringRef ModuleName,
const CodeGenOptions &CGO) {
if (ModuleName == "-" && !CGO.MainFileName.empty())
return CGO.MainFileName;
return ModuleName;
}
public:
CodeGeneratorImpl(DiagnosticsEngine &diags, llvm::StringRef ModuleName,
const HeaderSearchOptions &HSO,
const PreprocessorOptions &PPO, const CodeGenOptions &CGO,
llvm::LLVMContext &C,
CoverageSourceInfo *CoverageInfo = nullptr)
: Diags(diags), Ctx(nullptr), HeaderSearchOpts(HSO),
PreprocessorOpts(PPO), CodeGenOpts(CGO), HandlingTopLevelDecls(0),
CoverageInfo(CoverageInfo),
M(new llvm::Module(ExpandModuleName(ModuleName, CGO), C)) {
C.setDiscardValueNames(CGO.DiscardValueNames);
}
~CodeGeneratorImpl() override {
// There should normally not be any leftover inline method definitions.
assert(DeferredInlineMemberFuncDefs.empty() ||
Diags.hasErrorOccurred());
}
CodeGenModule &CGM() {
return *Builder;
}
llvm::Module *GetModule() {
return M.get();
}
CGDebugInfo *getCGDebugInfo() {
return Builder->getModuleDebugInfo();
}
llvm::Module *ReleaseModule() {
return M.release();
}
const Decl *GetDeclForMangledName(StringRef MangledName) {
GlobalDecl Result;
if (!Builder->lookupRepresentativeDecl(MangledName, Result))
return nullptr;
const Decl *D = Result.getCanonicalDecl().getDecl();
if (auto FD = dyn_cast<FunctionDecl>(D)) {
if (FD->hasBody(FD))
return FD;
} else if (auto TD = dyn_cast<TagDecl>(D)) {
if (auto Def = TD->getDefinition())
return Def;
}
return D;
}
llvm::StringRef GetMangledName(GlobalDecl GD) {
return Builder->getMangledName(GD);
}
llvm::Constant *GetAddrOfGlobal(GlobalDecl global, bool isForDefinition) {
return Builder->GetAddrOfGlobal(global, ForDefinition_t(isForDefinition));
}
llvm::Module *StartModule(llvm::StringRef ModuleName,
llvm::LLVMContext &C) {
assert(!M && "Replacing existing Module?");
M.reset(new llvm::Module(ExpandModuleName(ModuleName, CodeGenOpts), C));
std::unique_ptr<CodeGenModule> OldBuilder = std::move(Builder);
Initialize(*Ctx);
if (OldBuilder)
OldBuilder->moveLazyEmissionStates(Builder.get());
return M.get();
}
void Initialize(ASTContext &Context) override {
Ctx = &Context;
M->setTargetTriple(Ctx->getTargetInfo().getTriple().getTriple());
M->setDataLayout(Ctx->getTargetInfo().getDataLayoutString());
const auto &SDKVersion = Ctx->getTargetInfo().getSDKVersion();
if (!SDKVersion.empty())
M->setSDKVersion(SDKVersion);
if (const auto *TVT = Ctx->getTargetInfo().getDarwinTargetVariantTriple())
M->setDarwinTargetVariantTriple(TVT->getTriple());
if (auto TVSDKVersion =
Ctx->getTargetInfo().getDarwinTargetVariantSDKVersion())
M->setDarwinTargetVariantSDKVersion(*TVSDKVersion);
Builder.reset(new CodeGen::CodeGenModule(Context, HeaderSearchOpts,
PreprocessorOpts, CodeGenOpts,
*M, Diags, CoverageInfo));
for (auto &&Lib : CodeGenOpts.DependentLibraries)
Builder->AddDependentLib(Lib);
for (auto &&Opt : CodeGenOpts.LinkerOptions)
Builder->AppendLinkerOptions(Opt);
}
void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
if (Diags.hasErrorOccurred())
return;
Builder->HandleCXXStaticMemberVarInstantiation(VD);
}
bool HandleTopLevelDecl(DeclGroupRef DG) override {
if (Diags.hasErrorOccurred())
return true;
HandlingTopLevelDeclRAII HandlingDecl(*this);
// Make sure to emit all elements of a Decl.
for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
Builder->EmitTopLevelDecl(*I);
return true;
}
void EmitDeferredDecls() {
if (DeferredInlineMemberFuncDefs.empty())
return;
// Emit any deferred inline method definitions. Note that more deferred
// methods may be added during this loop, since ASTConsumer callbacks
// can be invoked if AST inspection results in declarations being added.
HandlingTopLevelDeclRAII HandlingDecl(*this);
for (unsigned I = 0; I != DeferredInlineMemberFuncDefs.size(); ++I)
Builder->EmitTopLevelDecl(DeferredInlineMemberFuncDefs[I]);
DeferredInlineMemberFuncDefs.clear();
}
void HandleInlineFunctionDefinition(FunctionDecl *D) override {
if (Diags.hasErrorOccurred())
return;
assert(D->doesThisDeclarationHaveABody());
// We may want to emit this definition. However, that decision might be
// based on computing the linkage, and we have to defer that in case we
// are inside of something that will change the method's final linkage,
// e.g.
// typedef struct {
// void bar();
// void foo() { bar(); }
// } A;
DeferredInlineMemberFuncDefs.push_back(D);
// Provide some coverage mapping even for methods that aren't emitted.
// Don't do this for templated classes though, as they may not be
// instantiable.
if (!D->getLexicalDeclContext()->isDependentContext())
Builder->AddDeferredUnusedCoverageMapping(D);
}
/// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
/// to (e.g. struct, union, enum, class) is completed. This allows the
/// client hack on the type, which can occur at any point in the file
/// (because these can be defined in declspecs).
void HandleTagDeclDefinition(TagDecl *D) override {
if (Diags.hasErrorOccurred())
return;
// Don't allow re-entrant calls to CodeGen triggered by PCH
// deserialization to emit deferred decls.
HandlingTopLevelDeclRAII HandlingDecl(*this, /*EmitDeferred=*/false);
Builder->UpdateCompletedType(D);
// For MSVC compatibility, treat declarations of static data members with
// inline initializers as definitions.
if (Ctx->getTargetInfo().getCXXABI().isMicrosoft()) {
for (Decl *Member : D->decls()) {
if (VarDecl *VD = dyn_cast<VarDecl>(Member)) {
if (Ctx->isMSStaticDataMemberInlineDefinition(VD) &&
Ctx->DeclMustBeEmitted(VD)) {
Builder->EmitGlobal(VD);
}
}
}
}
// For OpenMP emit declare reduction functions, if required.
if (Ctx->getLangOpts().OpenMP) {
for (Decl *Member : D->decls()) {
if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Member)) {
if (Ctx->DeclMustBeEmitted(DRD))
Builder->EmitGlobal(DRD);
} else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Member)) {
if (Ctx->DeclMustBeEmitted(DMD))
Builder->EmitGlobal(DMD);
}
}
}
}
void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
if (Diags.hasErrorOccurred())
return;
// Don't allow re-entrant calls to CodeGen triggered by PCH
// deserialization to emit deferred decls.
HandlingTopLevelDeclRAII HandlingDecl(*this, /*EmitDeferred=*/false);
if (CodeGen::CGDebugInfo *DI = Builder->getModuleDebugInfo())
if (const RecordDecl *RD = dyn_cast<RecordDecl>(D))
DI->completeRequiredType(RD);
}
void HandleTranslationUnit(ASTContext &Ctx) override {
// Release the Builder when there is no error.
if (!Diags.hasErrorOccurred() && Builder)
Builder->Release();
// If there are errors before or when releasing the Builder, reset
// the module to stop here before invoking the backend.
if (Diags.hasErrorOccurred()) {
if (Builder)
Builder->clear();
M.reset();
return;
}
}
void AssignInheritanceModel(CXXRecordDecl *RD) override {
if (Diags.hasErrorOccurred())
return;
Builder->RefreshTypeCacheForClass(RD);
}
void CompleteTentativeDefinition(VarDecl *D) override {
if (Diags.hasErrorOccurred())
return;
Builder->EmitTentativeDefinition(D);
}
void CompleteExternalDeclaration(VarDecl *D) override {
Builder->EmitExternalDeclaration(D);
}
void HandleVTable(CXXRecordDecl *RD) override {
if (Diags.hasErrorOccurred())
return;
Builder->EmitVTable(RD);
}
};
}
void CodeGenerator::anchor() { }
CodeGenModule &CodeGenerator::CGM() {
return static_cast<CodeGeneratorImpl*>(this)->CGM();
}
llvm::Module *CodeGenerator::GetModule() {
return static_cast<CodeGeneratorImpl*>(this)->GetModule();
}
llvm::Module *CodeGenerator::ReleaseModule() {
return static_cast<CodeGeneratorImpl*>(this)->ReleaseModule();
}
CGDebugInfo *CodeGenerator::getCGDebugInfo() {
return static_cast<CodeGeneratorImpl*>(this)->getCGDebugInfo();
}
const Decl *CodeGenerator::GetDeclForMangledName(llvm::StringRef name) {
return static_cast<CodeGeneratorImpl*>(this)->GetDeclForMangledName(name);
}
llvm::StringRef CodeGenerator::GetMangledName(GlobalDecl GD) {
return static_cast<CodeGeneratorImpl *>(this)->GetMangledName(GD);
}
llvm::Constant *CodeGenerator::GetAddrOfGlobal(GlobalDecl global,
bool isForDefinition) {
return static_cast<CodeGeneratorImpl*>(this)
->GetAddrOfGlobal(global, isForDefinition);
}
llvm::Module *CodeGenerator::StartModule(llvm::StringRef ModuleName,
llvm::LLVMContext &C) {
return static_cast<CodeGeneratorImpl*>(this)->StartModule(ModuleName, C);
}
CodeGenerator *clang::CreateLLVMCodeGen(
DiagnosticsEngine &Diags, llvm::StringRef ModuleName,
const HeaderSearchOptions &HeaderSearchOpts,
const PreprocessorOptions &PreprocessorOpts, const CodeGenOptions &CGO,
llvm::LLVMContext &C, CoverageSourceInfo *CoverageInfo) {
return new CodeGeneratorImpl(Diags, ModuleName, HeaderSearchOpts,
PreprocessorOpts, CGO, C, CoverageInfo);
}