//===--- GeneratePCH.cpp - Sema Consumer for PCH Generation -----*- C++ -*-===//

//

// 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 file defines the PCHGenerator, which as a SemaConsumer that generates

//  a PCH file.

//

//===----------------------------------------------------------------------===//

#include "clang/AST/ASTContext.h"

#include "clang/Lex/HeaderSearch.h"

#include "clang/Lex/Preprocessor.h"

#include "clang/Sema/SemaConsumer.h"

#include "clang/Serialization/ASTWriter.h"

#include "llvm/Bitstream/BitstreamWriter.h"

using namespace clang;

PCHGenerator::PCHGenerator(

    const Preprocessor &PP, InMemoryModuleCache &ModuleCache,

    StringRef OutputFile, StringRef isysroot, std::shared_ptr<PCHBuffer> Buffer,

    ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,

    bool AllowASTWithErrors, bool IncludeTimestamps,

    bool BuildingImplicitModule, bool ShouldCacheASTInMemory)

    : PP(PP), OutputFile(OutputFile), isysroot(isysroot.str()),

      SemaPtr(nullptr), Buffer(std::move(Buffer)), Stream(this->Buffer->Data),

      Writer(Stream, this->Buffer->Data, ModuleCache, Extensions,

             IncludeTimestamps, BuildingImplicitModule),

      AllowASTWithErrors(AllowASTWithErrors),

      ShouldCacheASTInMemory(ShouldCacheASTInMemory) {

  this->Buffer->IsComplete = false;

}

PCHGenerator::~PCHGenerator() {

}

void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {

  // Don't create a PCH if there were fatal failures during module loading.

  if (PP.getModuleLoader().HadFatalFailure)

    return;

  bool hasErrors = PP.getDiagnostics().hasErrorOccurred();

  if (hasErrors && !AllowASTWithErrors)

    return;

  Module *Module = nullptr;

  if (PP.getLangOpts().isCompilingModule()) {

    Module = PP.getHeaderSearchInfo().lookupModule(

        PP.getLangOpts().CurrentModule, SourceLocation(),

        /*AllowSearch*/ false);

    if (!Module) {

      assert(hasErrors && "emitting module but current module doesn't exist");

      return;

    }

  }

  // Errors that do not prevent the PCH from being written should not cause the

  // overall compilation to fail either.

  if (AllowASTWithErrors)

    PP.getDiagnostics().getClient()->clear();

  // Emit the PCH file to the Buffer.

  assert(SemaPtr && "No Sema?");

  Buffer->Signature = Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot,

                                      ShouldCacheASTInMemory);

  Buffer->IsComplete = true;

}

ASTMutationListener *PCHGenerator::GetASTMutationListener() {

  return &Writer;

}

ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {

  return &Writer;

}