Frontend: Factor clang::EmitBackendOutput out of CodeGenAction.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105575 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/BackendUtil.cpp b/lib/Frontend/BackendUtil.cpp
new file mode 100644
index 0000000..6b389a6
--- /dev/null
+++ b/lib/Frontend/BackendUtil.cpp
@@ -0,0 +1,328 @@
+//===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/BackendUtil.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/TargetOptions.h"
+#include "clang/CodeGen/CodeGenOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "llvm/Module.h"
+#include "llvm/PassManager.h"
+#include "llvm/Assembly/PrintModulePass.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/CodeGen/RegAllocRegistry.h"
+#include "llvm/CodeGen/SchedulerRegistry.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/StandardPasses.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/SubtargetFeature.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetRegistry.h"
+using namespace clang;
+using namespace llvm;
+
+namespace {
+
+class EmitAssemblyHelper {
+ Diagnostic &Diags;
+ const CodeGenOptions &CodeGenOpts;
+ const TargetOptions &TargetOpts;
+ Module *TheModule;
+ TargetData *TheTargetData;
+
+ Timer CodeGenerationTime;
+
+ mutable FunctionPassManager *CodeGenPasses;
+ mutable PassManager *PerModulePasses;
+ mutable FunctionPassManager *PerFunctionPasses;
+
+private:
+ FunctionPassManager *getCodeGenPasses() const {
+ if (!CodeGenPasses) {
+ CodeGenPasses = new FunctionPassManager(TheModule);
+ CodeGenPasses->add(new TargetData(*TheTargetData));
+ }
+ return CodeGenPasses;
+ }
+
+ PassManager *getPerModulePasses() const {
+ if (!PerModulePasses) {
+ PerModulePasses = new PassManager();
+ PerModulePasses->add(new TargetData(*TheTargetData));
+ }
+ return PerModulePasses;
+ }
+
+ FunctionPassManager *getPerFunctionPasses() const {
+ if (!PerFunctionPasses) {
+ PerFunctionPasses = new FunctionPassManager(TheModule);
+ PerFunctionPasses->add(new TargetData(*TheTargetData));
+ }
+ return PerFunctionPasses;
+ }
+
+ void CreatePasses();
+
+ /// AddEmitPasses - Add passes necessary to emit assembly or LLVM IR.
+ ///
+ /// \return True on success.
+ bool AddEmitPasses(BackendAction Action, formatted_raw_ostream &OS);
+
+public:
+ EmitAssemblyHelper(Diagnostic &_Diags,
+ const CodeGenOptions &CGOpts, const TargetOptions &TOpts,
+ Module *M, TargetData *TD)
+ : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts),
+ TheModule(M), TheTargetData(TD),
+ CodeGenerationTime("Code Generation Time"),
+ CodeGenPasses(0), PerModulePasses(0), PerFunctionPasses(0) {}
+
+ ~EmitAssemblyHelper() {
+ delete CodeGenPasses;
+ delete PerModulePasses;
+ delete PerFunctionPasses;
+ }
+
+ void EmitAssembly(BackendAction Action, raw_ostream *OS);
+};
+
+}
+
+void EmitAssemblyHelper::CreatePasses() {
+ unsigned OptLevel = CodeGenOpts.OptimizationLevel;
+ CodeGenOptions::InliningMethod Inlining = CodeGenOpts.Inlining;
+
+ // Handle disabling of LLVM optimization, where we want to preserve the
+ // internal module before any optimization.
+ if (CodeGenOpts.DisableLLVMOpts) {
+ OptLevel = 0;
+ Inlining = CodeGenOpts.NoInlining;
+ }
+
+ // In -O0 if checking is disabled, we don't even have per-function passes.
+ if (CodeGenOpts.VerifyModule)
+ getPerFunctionPasses()->add(createVerifierPass());
+
+ // Assume that standard function passes aren't run for -O0.
+ if (OptLevel > 0)
+ llvm::createStandardFunctionPasses(getPerFunctionPasses(), OptLevel);
+
+ llvm::Pass *InliningPass = 0;
+ switch (Inlining) {
+ case CodeGenOptions::NoInlining: break;
+ case CodeGenOptions::NormalInlining: {
+ // Set the inline threshold following llvm-gcc.
+ //
+ // FIXME: Derive these constants in a principled fashion.
+ unsigned Threshold = 225;
+ if (CodeGenOpts.OptimizeSize)
+ Threshold = 75;
+ else if (OptLevel > 2)
+ Threshold = 275;
+ InliningPass = createFunctionInliningPass(Threshold);
+ break;
+ }
+ case CodeGenOptions::OnlyAlwaysInlining:
+ InliningPass = createAlwaysInlinerPass(); // Respect always_inline
+ break;
+ }
+
+ // For now we always create per module passes.
+ llvm::createStandardModulePasses(getPerModulePasses(), OptLevel,
+ CodeGenOpts.OptimizeSize,
+ CodeGenOpts.UnitAtATime,
+ CodeGenOpts.UnrollLoops,
+ CodeGenOpts.SimplifyLibCalls,
+ /*HaveExceptions=*/true,
+ InliningPass);
+}
+
+bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
+ formatted_raw_ostream &OS) {
+ // Create the TargetMachine for generating code.
+ std::string Error;
+ std::string Triple = TheModule->getTargetTriple();
+ const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
+ if (!TheTarget) {
+ Diags.Report(diag::err_fe_unable_to_create_target) << Error;
+ return false;
+ }
+
+ // FIXME: Expose these capabilities via actual APIs!!!! Aside from just
+ // being gross, this is also totally broken if we ever care about
+ // concurrency.
+ llvm::NoFramePointerElim = CodeGenOpts.DisableFPElim;
+ if (CodeGenOpts.FloatABI == "soft")
+ llvm::FloatABIType = llvm::FloatABI::Soft;
+ else if (CodeGenOpts.FloatABI == "hard")
+ llvm::FloatABIType = llvm::FloatABI::Hard;
+ else {
+ assert(CodeGenOpts.FloatABI.empty() && "Invalid float abi!");
+ llvm::FloatABIType = llvm::FloatABI::Default;
+ }
+ NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
+ llvm::UseSoftFloat = CodeGenOpts.SoftFloat;
+ UnwindTablesMandatory = CodeGenOpts.UnwindTables;
+
+ TargetMachine::setAsmVerbosityDefault(CodeGenOpts.AsmVerbose);
+
+ TargetMachine::setFunctionSections(CodeGenOpts.FunctionSections);
+ TargetMachine::setDataSections (CodeGenOpts.DataSections);
+
+ // FIXME: Parse this earlier.
+ if (CodeGenOpts.RelocationModel == "static") {
+ TargetMachine::setRelocationModel(llvm::Reloc::Static);
+ } else if (CodeGenOpts.RelocationModel == "pic") {
+ TargetMachine::setRelocationModel(llvm::Reloc::PIC_);
+ } else {
+ assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" &&
+ "Invalid PIC model!");
+ TargetMachine::setRelocationModel(llvm::Reloc::DynamicNoPIC);
+ }
+ // FIXME: Parse this earlier.
+ if (CodeGenOpts.CodeModel == "small") {
+ TargetMachine::setCodeModel(llvm::CodeModel::Small);
+ } else if (CodeGenOpts.CodeModel == "kernel") {
+ TargetMachine::setCodeModel(llvm::CodeModel::Kernel);
+ } else if (CodeGenOpts.CodeModel == "medium") {
+ TargetMachine::setCodeModel(llvm::CodeModel::Medium);
+ } else if (CodeGenOpts.CodeModel == "large") {
+ TargetMachine::setCodeModel(llvm::CodeModel::Large);
+ } else {
+ assert(CodeGenOpts.CodeModel.empty() && "Invalid code model!");
+ TargetMachine::setCodeModel(llvm::CodeModel::Default);
+ }
+
+ std::vector<const char *> BackendArgs;
+ BackendArgs.push_back("clang"); // Fake program name.
+ if (!CodeGenOpts.DebugPass.empty()) {
+ BackendArgs.push_back("-debug-pass");
+ BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
+ }
+ if (!CodeGenOpts.LimitFloatPrecision.empty()) {
+ BackendArgs.push_back("-limit-float-precision");
+ BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
+ }
+ if (llvm::TimePassesIsEnabled)
+ BackendArgs.push_back("-time-passes");
+ BackendArgs.push_back(0);
+ llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
+ const_cast<char **>(&BackendArgs[0]));
+
+ std::string FeaturesStr;
+ if (TargetOpts.CPU.size() || TargetOpts.Features.size()) {
+ SubtargetFeatures Features;
+ Features.setCPU(TargetOpts.CPU);
+ for (std::vector<std::string>::const_iterator
+ it = TargetOpts.Features.begin(),
+ ie = TargetOpts.Features.end(); it != ie; ++it)
+ Features.AddFeature(*it);
+ FeaturesStr = Features.getString();
+ }
+ TargetMachine *TM = TheTarget->createTargetMachine(Triple, FeaturesStr);
+
+ if (CodeGenOpts.RelaxAll)
+ TM->setMCRelaxAll(true);
+
+ // Create the code generator passes.
+ FunctionPassManager *PM = getCodeGenPasses();
+ CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
+
+ switch (CodeGenOpts.OptimizationLevel) {
+ default: break;
+ case 0: OptLevel = CodeGenOpt::None; break;
+ case 3: OptLevel = CodeGenOpt::Aggressive; break;
+ }
+
+ // Normal mode, emit a .s or .o file by running the code generator. Note,
+ // this also adds codegenerator level optimization passes.
+ TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
+ if (Action == Backend_EmitObj)
+ CGFT = TargetMachine::CGFT_ObjectFile;
+ else if (Action == Backend_EmitMCNull)
+ CGFT = TargetMachine::CGFT_Null;
+ else
+ assert(Action == Backend_EmitAssembly && "Invalid action!");
+ if (TM->addPassesToEmitFile(*PM, OS, CGFT, OptLevel,
+ /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
+ Diags.Report(diag::err_fe_unable_to_interface_with_target);
+ return false;
+ }
+
+ return true;
+}
+
+void EmitAssemblyHelper::EmitAssembly(BackendAction Action, raw_ostream *OS) {
+ TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : 0);
+ llvm::formatted_raw_ostream FormattedOS;
+
+ CreatePasses();
+ switch (Action) {
+ case Backend_EmitNothing:
+ break;
+
+ case Backend_EmitBC:
+ getPerModulePasses()->add(createBitcodeWriterPass(*OS));
+ break;
+
+ case Backend_EmitLL:
+ FormattedOS.setStream(*OS, formatted_raw_ostream::PRESERVE_STREAM);
+ getPerModulePasses()->add(createPrintModulePass(&FormattedOS));
+ break;
+
+ default:
+ FormattedOS.setStream(*OS, formatted_raw_ostream::PRESERVE_STREAM);
+ if (!AddEmitPasses(Action, FormattedOS))
+ return;
+ }
+
+ // Run passes. For now we do all passes at once, but eventually we
+ // would like to have the option of streaming code generation.
+
+ if (PerFunctionPasses) {
+ PrettyStackTraceString CrashInfo("Per-function optimization");
+
+ PerFunctionPasses->doInitialization();
+ for (Module::iterator I = TheModule->begin(),
+ E = TheModule->end(); I != E; ++I)
+ if (!I->isDeclaration())
+ PerFunctionPasses->run(*I);
+ PerFunctionPasses->doFinalization();
+ }
+
+ if (PerModulePasses) {
+ PrettyStackTraceString CrashInfo("Per-module optimization passes");
+ PerModulePasses->run(*TheModule);
+ }
+
+ if (CodeGenPasses) {
+ PrettyStackTraceString CrashInfo("Code generation");
+
+ CodeGenPasses->doInitialization();
+ for (Module::iterator I = TheModule->begin(),
+ E = TheModule->end(); I != E; ++I)
+ if (!I->isDeclaration())
+ CodeGenPasses->run(*I);
+ CodeGenPasses->doFinalization();
+ }
+}
+
+void clang::EmitBackendOutput(Diagnostic &Diags, const CodeGenOptions &CGOpts,
+ const TargetOptions &TOpts, Module *M,
+ TargetData *TD, BackendAction Action,
+ raw_ostream *OS) {
+ EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, M, TD);
+
+ AsmHelper.EmitAssembly(Action, OS);
+}