vendor/clang/clang-trunk-r242221

1 files changed, 193 insertions, 0 deletions

diff --git a/lib/CodeGen/ObjectFilePCHContainerOperations.cpp b/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
new file mode 100644
index 000000000000..8f04e06988d8
--- /dev/null
+++ b/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
@@ -0,0 +1,193 @@
+//===--- ObjectFilePCHContainerOperations.cpp -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CodeGen/ObjectFilePCHContainerOperations.h"
+#include "CGDebugInfo.h"
+#include "CodeGenModule.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/CodeGen/BackendUtil.h"
+#include "clang/Frontend/CodeGenOptions.h"
+#include "clang/Serialization/ASTWriter.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Bitcode/BitstreamReader.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Object/COFF.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/TargetRegistry.h"
+#include <memory>
+using namespace clang;
+
+#define DEBUG_TYPE "pchcontainer"
+
+namespace {
+class PCHContainerGenerator : public ASTConsumer {
+  DiagnosticsEngine &Diags;
+  const std::string MainFileName;
+  ASTContext *Ctx;
+  const HeaderSearchOptions &HeaderSearchOpts;
+  const PreprocessorOptions &PreprocessorOpts;
+  CodeGenOptions CodeGenOpts;
+  const TargetOptions TargetOpts;
+  const LangOptions LangOpts;
+  std::unique_ptr<llvm::LLVMContext> VMContext;
+  std::unique_ptr<llvm::Module> M;
+  std::unique_ptr<CodeGen::CodeGenModule> Builder;
+  raw_pwrite_stream *OS;
+  std::shared_ptr<PCHBuffer> Buffer;
+
+public:
+  PCHContainerGenerator(DiagnosticsEngine &diags,
+                        const HeaderSearchOptions &HSO,
+                        const PreprocessorOptions &PPO, const TargetOptions &TO,
+                        const LangOptions &LO, const std::string &MainFileName,
+                        const std::string &OutputFileName,
+                        raw_pwrite_stream *OS,
+                        std::shared_ptr<PCHBuffer> Buffer)
+      : Diags(diags), HeaderSearchOpts(HSO), PreprocessorOpts(PPO),
+        TargetOpts(TO), LangOpts(LO), OS(OS), Buffer(Buffer) {
+    // The debug info output isn't affected by CodeModel and
+    // ThreadModel, but the backend expects them to be nonempty.
+    CodeGenOpts.CodeModel = "default";
+    CodeGenOpts.ThreadModel = "single";
+    CodeGenOpts.setDebugInfo(CodeGenOptions::FullDebugInfo);
+    CodeGenOpts.SplitDwarfFile = OutputFileName;
+  }
+
+  virtual ~PCHContainerGenerator() {}
+
+  void Initialize(ASTContext &Context) override {
+    Ctx = &Context;
+    VMContext.reset(new llvm::LLVMContext());
+    M.reset(new llvm::Module(MainFileName, *VMContext));
+    M->setDataLayout(Ctx->getTargetInfo().getTargetDescription());
+    Builder.reset(new CodeGen::CodeGenModule(*Ctx, HeaderSearchOpts,
+                                             PreprocessorOpts, CodeGenOpts, *M,
+                                             M->getDataLayout(), Diags));
+  }
+
+  /// Emit a container holding the serialized AST.
+  void HandleTranslationUnit(ASTContext &Ctx) override {
+    assert(M && VMContext && Builder);
+    // Delete these on function exit.
+    std::unique_ptr<llvm::LLVMContext> VMContext = std::move(this->VMContext);
+    std::unique_ptr<llvm::Module> M = std::move(this->M);
+    std::unique_ptr<CodeGen::CodeGenModule> Builder = std::move(this->Builder);
+
+    if (Diags.hasErrorOccurred())
+      return;
+
+    M->setTargetTriple(Ctx.getTargetInfo().getTriple().getTriple());
+    M->setDataLayout(Ctx.getTargetInfo().getTargetDescription());
+
+    // Finalize the Builder.
+    if (Builder)
+      Builder->Release();
+
+    // Ensure the target exists.
+    std::string Error;
+    auto Triple = Ctx.getTargetInfo().getTriple();
+    if (!llvm::TargetRegistry::lookupTarget(Triple.getTriple(), Error))
+      llvm::report_fatal_error(Error);
+
+    // Emit the serialized Clang AST into its own section.
+    assert(Buffer->IsComplete && "serialization did not complete");
+    auto &SerializedAST = Buffer->Data;
+    auto Size = SerializedAST.size();
+    auto Int8Ty = llvm::Type::getInt8Ty(*VMContext);
+    auto *Ty = llvm::ArrayType::get(Int8Ty, Size);
+    auto *Data = llvm::ConstantDataArray::getString(
+        *VMContext, StringRef(SerializedAST.data(), Size),
+        /*AddNull=*/false);
+    auto *ASTSym = new llvm::GlobalVariable(
+        *M, Ty, /*constant*/ true, llvm::GlobalVariable::InternalLinkage, Data,
+        "__clang_ast");
+    // The on-disk hashtable needs to be aligned.
+    ASTSym->setAlignment(8);
+
+    // Mach-O also needs a segment name.
+    if (Triple.isOSBinFormatMachO())
+      ASTSym->setSection("__CLANG,__clangast");
+    // COFF has an eight character length limit.
+    else if (Triple.isOSBinFormatCOFF())
+      ASTSym->setSection("clangast");
+    else
+      ASTSym->setSection("__clangast");
+
+    DEBUG({
+      // Print the IR for the PCH container to the debug output.
+      llvm::SmallString<0> Buffer;
+      llvm::raw_svector_ostream OS(Buffer);
+      clang::EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
+                               Ctx.getTargetInfo().getTargetDescription(),
+                               M.get(), BackendAction::Backend_EmitLL, &OS);
+      OS.flush();
+      llvm::dbgs() << Buffer;
+    });
+
+    // Use the LLVM backend to emit the pch container.
+    clang::EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
+                             Ctx.getTargetInfo().getTargetDescription(),
+                             M.get(), BackendAction::Backend_EmitObj, OS);
+
+    // Make sure the pch container hits disk.
+    OS->flush();
+
+    // Free the memory for the temporary buffer.
+    llvm::SmallVector<char, 0> Empty;
+    SerializedAST = std::move(Empty);
+  }
+};
+
+} // namespace
+
+std::unique_ptr<ASTConsumer>
+ObjectFilePCHContainerOperations::CreatePCHContainerGenerator(
+    DiagnosticsEngine &Diags, const HeaderSearchOptions &HSO,
+    const PreprocessorOptions &PPO, const TargetOptions &TO,
+    const LangOptions &LO, const std::string &MainFileName,
+    const std::string &OutputFileName, llvm::raw_pwrite_stream *OS,
+    std::shared_ptr<PCHBuffer> Buffer) const {
+  return llvm::make_unique<PCHContainerGenerator>(
+      Diags, HSO, PPO, TO, LO, MainFileName, OutputFileName, OS, Buffer);
+}
+
+void ObjectFilePCHContainerOperations::ExtractPCH(
+    llvm::MemoryBufferRef Buffer, llvm::BitstreamReader &StreamFile) const {
+  if (auto OF = llvm::object::ObjectFile::createObjectFile(Buffer)) {
+    auto *Obj = OF.get().get();
+    bool IsCOFF = isa<llvm::object::COFFObjectFile>(Obj);
+    // Find the clang AST section in the container.
+    for (auto &Section : OF->get()->sections()) {
+      StringRef Name;
+      Section.getName(Name);
+      if ((!IsCOFF && Name == "__clangast") ||
+          ( IsCOFF && Name ==   "clangast")) {
+        StringRef Buf;
+        Section.getContents(Buf);
+        StreamFile.init((const unsigned char *)Buf.begin(),
+                        (const unsigned char *)Buf.end());
+        return;
+      }
+    }
+  }
+
+  // As a fallback, treat the buffer as a raw AST.
+  StreamFile.init((const unsigned char *)Buffer.getBufferStart(),
+                  (const unsigned char *)Buffer.getBufferEnd());
+  return;
+}