forked from OSchip/llvm-project
417 lines
14 KiB
C++
417 lines
14 KiB
C++
//===--- Backend.cpp - Interface to LLVM backend technologies -------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Frontend/ASTConsumers.h"
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#include "clang/AST/ASTConsumer.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/DeclGroup.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/Basic/TargetOptions.h"
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#include "clang/CodeGen/CodeGenOptions.h"
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#include "clang/CodeGen/ModuleBuilder.h"
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#include "llvm/Module.h"
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#include "llvm/ModuleProvider.h"
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#include "llvm/PassManager.h"
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#include "llvm/ADT/OwningPtr.h"
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#include "llvm/Assembly/PrintModulePass.h"
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#include "llvm/Analysis/CallGraph.h"
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#include "llvm/Analysis/Verifier.h"
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#include "llvm/Bitcode/ReaderWriter.h"
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#include "llvm/CodeGen/RegAllocRegistry.h"
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#include "llvm/CodeGen/SchedulerRegistry.h"
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#include "llvm/Support/FormattedStream.h"
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#include "llvm/Support/StandardPasses.h"
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#include "llvm/Support/Timer.h"
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#include "llvm/Target/SubtargetFeature.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetRegistry.h"
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using namespace clang;
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using namespace llvm;
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namespace {
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class BackendConsumer : public ASTConsumer {
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BackendAction Action;
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const CodeGenOptions &CodeGenOpts;
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const LangOptions &LangOpts;
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const TargetOptions &TargetOpts;
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llvm::raw_ostream *AsmOutStream;
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llvm::formatted_raw_ostream FormattedOutStream;
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ASTContext *Context;
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Timer LLVMIRGeneration;
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Timer CodeGenerationTime;
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llvm::OwningPtr<CodeGenerator> Gen;
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llvm::Module *TheModule;
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llvm::TargetData *TheTargetData;
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mutable llvm::ModuleProvider *ModuleProvider;
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mutable FunctionPassManager *CodeGenPasses;
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mutable PassManager *PerModulePasses;
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mutable FunctionPassManager *PerFunctionPasses;
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FunctionPassManager *getCodeGenPasses() const;
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PassManager *getPerModulePasses() const;
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FunctionPassManager *getPerFunctionPasses() const;
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void CreatePasses();
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/// AddEmitPasses - Add passes necessary to emit assembly or LLVM
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/// IR.
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///
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/// \return True on success. On failure \arg Error will be set to
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/// a user readable error message.
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bool AddEmitPasses(std::string &Error);
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void EmitAssembly();
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public:
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BackendConsumer(BackendAction action, Diagnostic &Diags,
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const LangOptions &langopts, const CodeGenOptions &compopts,
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const TargetOptions &targetopts, bool TimePasses,
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const std::string &infile, llvm::raw_ostream *OS,
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LLVMContext& C) :
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Action(action),
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CodeGenOpts(compopts),
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LangOpts(langopts),
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TargetOpts(targetopts),
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AsmOutStream(OS),
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LLVMIRGeneration("LLVM IR Generation Time"),
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CodeGenerationTime("Code Generation Time"),
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Gen(CreateLLVMCodeGen(Diags, infile, compopts, C)),
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TheModule(0), TheTargetData(0), ModuleProvider(0),
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CodeGenPasses(0), PerModulePasses(0), PerFunctionPasses(0) {
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if (AsmOutStream)
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FormattedOutStream.setStream(*AsmOutStream,
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formatted_raw_ostream::PRESERVE_STREAM);
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llvm::TimePassesIsEnabled = TimePasses;
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}
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~BackendConsumer() {
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delete TheTargetData;
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delete ModuleProvider;
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delete CodeGenPasses;
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delete PerModulePasses;
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delete PerFunctionPasses;
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}
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virtual void Initialize(ASTContext &Ctx) {
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Context = &Ctx;
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if (llvm::TimePassesIsEnabled)
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LLVMIRGeneration.startTimer();
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Gen->Initialize(Ctx);
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TheModule = Gen->GetModule();
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ModuleProvider = new ExistingModuleProvider(TheModule);
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TheTargetData = new llvm::TargetData(Ctx.Target.getTargetDescription());
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if (llvm::TimePassesIsEnabled)
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LLVMIRGeneration.stopTimer();
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}
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virtual void HandleTopLevelDecl(DeclGroupRef D) {
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PrettyStackTraceDecl CrashInfo(*D.begin(), SourceLocation(),
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Context->getSourceManager(),
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"LLVM IR generation of declaration");
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if (llvm::TimePassesIsEnabled)
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LLVMIRGeneration.startTimer();
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Gen->HandleTopLevelDecl(D);
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if (llvm::TimePassesIsEnabled)
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LLVMIRGeneration.stopTimer();
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}
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virtual void HandleTranslationUnit(ASTContext &C) {
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{
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PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
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if (llvm::TimePassesIsEnabled)
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LLVMIRGeneration.startTimer();
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Gen->HandleTranslationUnit(C);
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if (llvm::TimePassesIsEnabled)
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LLVMIRGeneration.stopTimer();
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}
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// EmitAssembly times and registers crash info itself.
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EmitAssembly();
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// Force a flush here in case we never get released.
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if (AsmOutStream)
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FormattedOutStream.flush();
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}
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virtual void HandleTagDeclDefinition(TagDecl *D) {
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PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
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Context->getSourceManager(),
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"LLVM IR generation of declaration");
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Gen->HandleTagDeclDefinition(D);
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}
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virtual void CompleteTentativeDefinition(VarDecl *D) {
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Gen->CompleteTentativeDefinition(D);
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}
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};
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}
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FunctionPassManager *BackendConsumer::getCodeGenPasses() const {
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if (!CodeGenPasses) {
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CodeGenPasses = new FunctionPassManager(ModuleProvider);
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CodeGenPasses->add(new TargetData(*TheTargetData));
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}
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return CodeGenPasses;
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}
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PassManager *BackendConsumer::getPerModulePasses() const {
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if (!PerModulePasses) {
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PerModulePasses = new PassManager();
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PerModulePasses->add(new TargetData(*TheTargetData));
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}
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return PerModulePasses;
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}
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FunctionPassManager *BackendConsumer::getPerFunctionPasses() const {
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if (!PerFunctionPasses) {
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PerFunctionPasses = new FunctionPassManager(ModuleProvider);
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PerFunctionPasses->add(new TargetData(*TheTargetData));
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}
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return PerFunctionPasses;
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}
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bool BackendConsumer::AddEmitPasses(std::string &Error) {
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if (Action == Backend_EmitNothing)
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return true;
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if (Action == Backend_EmitBC) {
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getPerModulePasses()->add(createBitcodeWriterPass(FormattedOutStream));
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} else if (Action == Backend_EmitLL) {
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getPerModulePasses()->add(createPrintModulePass(&FormattedOutStream));
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} else {
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bool Fast = CodeGenOpts.OptimizationLevel == 0;
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// Create the TargetMachine for generating code.
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std::string Triple = TheModule->getTargetTriple();
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const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
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if (!TheTarget) {
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Error = std::string("Unable to get target machine: ") + Error;
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return false;
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}
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// FIXME: Expose these capabilities via actual APIs!!!! Aside from just
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// being gross, this is also totally broken if we ever care about
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// concurrency.
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std::vector<const char *> BackendArgs;
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BackendArgs.push_back("clang"); // Fake program name.
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if (CodeGenOpts.AsmVerbose)
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BackendArgs.push_back("-asm-verbose");
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if (!CodeGenOpts.CodeModel.empty()) {
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BackendArgs.push_back("-code-model");
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BackendArgs.push_back(CodeGenOpts.CodeModel.c_str());
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}
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if (!CodeGenOpts.DebugPass.empty()) {
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BackendArgs.push_back("-debug-pass");
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BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
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}
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if (CodeGenOpts.DisableFPElim)
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BackendArgs.push_back("-disable-fp-elim");
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if (!CodeGenOpts.LimitFloatPrecision.empty()) {
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BackendArgs.push_back("-limit-float-precision");
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BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
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}
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if (CodeGenOpts.NoZeroInitializedInBSS)
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BackendArgs.push_back("-nozero-initialized-in-bss");
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BackendArgs.push_back("-relocation-model");
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BackendArgs.push_back(CodeGenOpts.RelocationModel.c_str());
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if (llvm::TimePassesIsEnabled)
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BackendArgs.push_back("-time-passes");
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if (CodeGenOpts.UnwindTables)
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BackendArgs.push_back("-unwind-tables");
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BackendArgs.push_back(0);
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llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
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(char**) &BackendArgs[0]);
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std::string FeaturesStr;
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if (TargetOpts.CPU.size() || TargetOpts.Features.size()) {
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SubtargetFeatures Features;
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Features.setCPU(TargetOpts.CPU);
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for (std::vector<std::string>::const_iterator
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it = TargetOpts.Features.begin(),
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ie = TargetOpts.Features.end(); it != ie; ++it)
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Features.AddFeature(*it);
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FeaturesStr = Features.getString();
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}
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TargetMachine *TM = TheTarget->createTargetMachine(Triple, FeaturesStr);
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// Set register scheduler & allocation policy.
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RegisterScheduler::setDefault(createDefaultScheduler);
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RegisterRegAlloc::setDefault(Fast ? createLocalRegisterAllocator :
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createLinearScanRegisterAllocator);
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// From llvm-gcc:
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// If there are passes we have to run on the entire module, we do codegen
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// as a separate "pass" after that happens.
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// FIXME: This is disabled right now until bugs can be worked out. Reenable
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// this for fast -O0 compiles!
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FunctionPassManager *PM = getCodeGenPasses();
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CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
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switch (CodeGenOpts.OptimizationLevel) {
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default: break;
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case 0: OptLevel = CodeGenOpt::None; break;
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case 3: OptLevel = CodeGenOpt::Aggressive; break;
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}
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// Normal mode, emit a .s file by running the code generator.
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// Note, this also adds codegenerator level optimization passes.
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switch (TM->addPassesToEmitFile(*PM, FormattedOutStream,
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TargetMachine::AssemblyFile, OptLevel)) {
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default:
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case FileModel::Error:
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Error = "Unable to interface with target machine!\n";
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return false;
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case FileModel::AsmFile:
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break;
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}
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if (TM->addPassesToEmitFileFinish(*CodeGenPasses, (MachineCodeEmitter *)0,
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OptLevel)) {
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Error = "Unable to interface with target machine!\n";
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return false;
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}
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}
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return true;
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}
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void BackendConsumer::CreatePasses() {
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unsigned OptLevel = CodeGenOpts.OptimizationLevel;
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CodeGenOptions::InliningMethod Inlining = CodeGenOpts.Inlining;
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// Handle disabling of LLVM optimization, where we want to preserve the
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// internal module before any optimization.
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if (CodeGenOpts.DisableLLVMOpts) {
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OptLevel = 0;
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Inlining = CodeGenOpts.NoInlining;
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}
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// In -O0 if checking is disabled, we don't even have per-function passes.
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if (CodeGenOpts.VerifyModule)
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getPerFunctionPasses()->add(createVerifierPass());
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// Assume that standard function passes aren't run for -O0.
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if (OptLevel > 0)
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llvm::createStandardFunctionPasses(getPerFunctionPasses(), OptLevel);
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llvm::Pass *InliningPass = 0;
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switch (Inlining) {
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case CodeGenOptions::NoInlining: break;
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case CodeGenOptions::NormalInlining: {
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// Inline small functions
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unsigned Threshold = (CodeGenOpts.OptimizeSize || OptLevel < 3) ? 50 : 200;
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InliningPass = createFunctionInliningPass(Threshold);
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break;
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}
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case CodeGenOptions::OnlyAlwaysInlining:
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InliningPass = createAlwaysInlinerPass(); // Respect always_inline
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break;
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}
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// For now we always create per module passes.
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PassManager *PM = getPerModulePasses();
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llvm::createStandardModulePasses(PM, OptLevel, CodeGenOpts.OptimizeSize,
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CodeGenOpts.UnitAtATime,
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CodeGenOpts.UnrollLoops,
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/*SimplifyLibCalls=*/!LangOpts.NoBuiltin,
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/*HaveExceptions=*/true,
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InliningPass);
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}
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/// EmitAssembly - Handle interaction with LLVM backend to generate
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/// actual machine code.
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void BackendConsumer::EmitAssembly() {
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// Silently ignore if we weren't initialized for some reason.
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if (!TheModule || !TheTargetData)
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return;
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TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : 0);
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// Make sure IR generation is happy with the module. This is
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// released by the module provider.
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Module *M = Gen->ReleaseModule();
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if (!M) {
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// The module has been released by IR gen on failures, do not
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// double free.
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ModuleProvider->releaseModule();
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TheModule = 0;
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return;
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}
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assert(TheModule == M && "Unexpected module change during IR generation");
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CreatePasses();
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std::string Error;
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if (!AddEmitPasses(Error)) {
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// FIXME: Don't fail this way.
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llvm::errs() << "ERROR: " << Error << "\n";
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::exit(1);
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}
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// Run passes. For now we do all passes at once, but eventually we
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// would like to have the option of streaming code generation.
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if (PerFunctionPasses) {
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PrettyStackTraceString CrashInfo("Per-function optimization");
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PerFunctionPasses->doInitialization();
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for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
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if (!I->isDeclaration())
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PerFunctionPasses->run(*I);
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PerFunctionPasses->doFinalization();
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}
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if (PerModulePasses) {
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PrettyStackTraceString CrashInfo("Per-module optimization passes");
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PerModulePasses->run(*M);
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}
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if (CodeGenPasses) {
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PrettyStackTraceString CrashInfo("Code generation");
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CodeGenPasses->doInitialization();
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for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
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if (!I->isDeclaration())
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CodeGenPasses->run(*I);
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CodeGenPasses->doFinalization();
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}
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}
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ASTConsumer *clang::CreateBackendConsumer(BackendAction Action,
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Diagnostic &Diags,
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const LangOptions &LangOpts,
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const CodeGenOptions &CodeGenOpts,
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const TargetOptions &TargetOpts,
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bool TimePasses,
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const std::string& InFile,
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llvm::raw_ostream* OS,
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LLVMContext& C) {
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return new BackendConsumer(Action, Diags, LangOpts, CodeGenOpts,
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TargetOpts, TimePasses, InFile, OS, C);
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}
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