//===--- CompilerInstance.cpp ---------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "clang/Frontend/CompilerInstance.h"
#include "clang/AST/ASTContext.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/PTHManager.h"
#include "clang/Frontend/ChainedDiagnosticClient.h"
#include "clang/Frontend/PCHReader.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/TextDiagnosticBuffer.h"
#include "clang/Frontend/TextDiagnosticPrinter.h"
#include "clang/Frontend/Utils.h"
#include "clang/Sema/CodeCompleteConsumer.h"
#include "llvm/LLVMContext.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;

CompilerInstance::CompilerInstance(llvm::LLVMContext *_LLVMContext,
                                   bool _OwnsLLVMContext)
  : LLVMContext(_LLVMContext),
    OwnsLLVMContext(_OwnsLLVMContext) {
    }

CompilerInstance::~CompilerInstance() {
  if (OwnsLLVMContext)
    delete LLVMContext;
}

// Diagnostics

static void SetUpBuildDumpLog(const DiagnosticOptions &DiagOpts,
                              unsigned argc, char **argv,
                              llvm::OwningPtr<DiagnosticClient> &DiagClient) {
  std::string ErrorInfo;
  llvm::raw_ostream *OS =
    new llvm::raw_fd_ostream(DiagOpts.DumpBuildInformation.c_str(), ErrorInfo);
  if (!ErrorInfo.empty()) {
    // FIXME: Do not fail like this.
    llvm::errs() << "error opening -dump-build-information file '"
                 << DiagOpts.DumpBuildInformation << "', option ignored!\n";
    delete OS;
    return;
  }

  (*OS) << "clang-cc command line arguments: ";
  for (unsigned i = 0; i != argc; ++i)
    (*OS) << argv[i] << ' ';
  (*OS) << '\n';

  // Chain in a diagnostic client which will log the diagnostics.
  DiagnosticClient *Logger =
    new TextDiagnosticPrinter(*OS, DiagOpts, /*OwnsOutputStream=*/true);
  DiagClient.reset(new ChainedDiagnosticClient(DiagClient.take(), Logger));
}

void CompilerInstance::createDiagnostics(int Argc, char **Argv) {
  Diagnostics.reset(createDiagnostics(getDiagnosticOpts(), Argc, Argv));

  if (Diagnostics)
    DiagClient.reset(Diagnostics->getClient());
}

Diagnostic *CompilerInstance::createDiagnostics(const DiagnosticOptions &Opts,
                                                int Argc, char **Argv) {
  // Create the diagnostic client for reporting errors or for
  // implementing -verify.
  llvm::OwningPtr<DiagnosticClient> DiagClient;
  if (Opts.VerifyDiagnostics) {
    // When checking diagnostics, just buffer them up.
    DiagClient.reset(new TextDiagnosticBuffer());
  } else {
    DiagClient.reset(new TextDiagnosticPrinter(llvm::errs(), Opts));
  }

  if (!Opts.DumpBuildInformation.empty())
    SetUpBuildDumpLog(Opts, Argc, Argv, DiagClient);

  // Configure our handling of diagnostics.
  Diagnostic *Diags = new Diagnostic(DiagClient.take());
  if (ProcessWarningOptions(*Diags, Opts))
    return 0;

  return Diags;
}

// File Manager

void CompilerInstance::createFileManager() {
  FileMgr.reset(new FileManager());
}

// Source Manager

void CompilerInstance::createSourceManager() {
  SourceMgr.reset(new SourceManager());
}

// Preprocessor

void CompilerInstance::createPreprocessor() {
  PP.reset(createPreprocessor(getDiagnostics(), getLangOpts(),
                              getPreprocessorOpts(), getHeaderSearchOpts(),
                              getDependencyOutputOpts(), getTarget(),
                              getSourceManager(), getFileManager()));
}

Preprocessor *
CompilerInstance::createPreprocessor(Diagnostic &Diags,
                                     const LangOptions &LangInfo,
                                     const PreprocessorOptions &PPOpts,
                                     const HeaderSearchOptions &HSOpts,
                                     const DependencyOutputOptions &DepOpts,
                                     const TargetInfo &Target,
                                     SourceManager &SourceMgr,
                                     FileManager &FileMgr) {
  // Create a PTH manager if we are using some form of a token cache.
  PTHManager *PTHMgr = 0;
  if (!PPOpts.getTokenCache().empty())
    PTHMgr = PTHManager::Create(PPOpts.getTokenCache(), Diags);

  // FIXME: Don't fail like this.
  if (Diags.hasErrorOccurred())
    exit(1);

  // Create the Preprocessor.
  HeaderSearch *HeaderInfo = new HeaderSearch(FileMgr);
  Preprocessor *PP = new Preprocessor(Diags, LangInfo, Target,
                                      SourceMgr, *HeaderInfo, PTHMgr,
                                      /*OwnsHeaderSearch=*/true);

  // Note that this is different then passing PTHMgr to Preprocessor's ctor.
  // That argument is used as the IdentifierInfoLookup argument to
  // IdentifierTable's ctor.
  if (PTHMgr) {
    PTHMgr->setPreprocessor(PP);
    PP->setPTHManager(PTHMgr);
  }

  InitializePreprocessor(*PP, PPOpts, HSOpts);

  // Handle generating dependencies, if requested.
  if (!DepOpts.OutputFile.empty())
    AttachDependencyFileGen(*PP, DepOpts);

  return PP;
}

// ASTContext

void CompilerInstance::createASTContext() {
  Preprocessor &PP = getPreprocessor();
  Context.reset(new ASTContext(getLangOpts(), PP.getSourceManager(),
                               getTarget(), PP.getIdentifierTable(),
                               PP.getSelectorTable(), PP.getBuiltinInfo(),
                               /*FreeMemory=*/ !getFrontendOpts().DisableFree,
                               /*size_reserve=*/ 0));
}

// ExternalASTSource

void CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path) {
  llvm::OwningPtr<ExternalASTSource> Source;
  Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
                                          getPreprocessor(), getASTContext()));
  getASTContext().setExternalSource(Source);
}

ExternalASTSource *
CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path,
                                             const std::string &Sysroot,
                                             Preprocessor &PP,
                                             ASTContext &Context) {
  llvm::OwningPtr<PCHReader> Reader;
  Reader.reset(new PCHReader(PP, &Context,
                             Sysroot.empty() ? 0 : Sysroot.c_str()));

  switch (Reader->ReadPCH(Path)) {
  case PCHReader::Success:
    // Set the predefines buffer as suggested by the PCH reader. Typically, the
    // predefines buffer will be empty.
    PP.setPredefines(Reader->getSuggestedPredefines());
    return Reader.take();

  case PCHReader::Failure:
    // Unrecoverable failure: don't even try to process the input file.
    break;

  case PCHReader::IgnorePCH:
    // No suitable PCH file could be found. Return an error.
    break;
  }

  return 0;
}

// Code Completion

void CompilerInstance::createCodeCompletionConsumer() {
  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
  CompletionConsumer.reset(
    createCodeCompletionConsumer(getPreprocessor(),
                                 Loc.FileName, Loc.Line, Loc.Column,
                                 getFrontendOpts().DebugCodeCompletionPrinter,
                                 getFrontendOpts().ShowMacrosInCodeCompletion,
                                 llvm::outs()));
}

CodeCompleteConsumer *
CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
                                               const std::string &Filename,
                                               unsigned Line,
                                               unsigned Column,
                                               bool UseDebugPrinter,
                                               bool ShowMacros,
                                               llvm::raw_ostream &OS) {
  // Tell the source manager to chop off the given file at a specific
  // line and column.
  const FileEntry *Entry = PP.getFileManager().getFile(Filename);
  if (!Entry) {
    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
      << Filename;
    return 0;
  }

  // Truncate the named file at the given line/column.
  PP.getSourceManager().truncateFileAt(Entry, Line, Column);

  // Set up the creation routine for code-completion.
  if (UseDebugPrinter)
    return new PrintingCodeCompleteConsumer(ShowMacros, OS);
  else
    return new CIndexCodeCompleteConsumer(ShowMacros, OS);
}