clang/lib/Serialization/GeneratePCH.cpp

   1 //===--- GeneratePCH.cpp - Sema Consumer for PCH Generation -----*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file defines the PCHGenerator, which as a SemaConsumer that generates
  10 //  a PCH file.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/AST/ASTContext.h"
  15 #include "clang/Lex/HeaderSearch.h"
  16 #include "clang/Lex/Preprocessor.h"
  17 #include "clang/Sema/SemaConsumer.h"
  18 #include "clang/Serialization/ASTWriter.h"
  19 #include "llvm/Bitstream/BitstreamWriter.h"
  20
  21 using namespace clang;
  22
  23 PCHGenerator::PCHGenerator(
  24     const Preprocessor &PP, InMemoryModuleCache &ModuleCache,
  25     StringRef OutputFile, StringRef isysroot, std::shared_ptr<PCHBuffer> Buffer,
  26     ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
  27     bool AllowASTWithErrors, bool IncludeTimestamps,
  28     bool ShouldCacheASTInMemory)
  29     : PP(PP), OutputFile(OutputFile), isysroot(isysroot.str()),
  30       SemaPtr(nullptr), Buffer(std::move(Buffer)), Stream(this->Buffer->Data),
  31       Writer(Stream, this->Buffer->Data, ModuleCache, Extensions,
  32              IncludeTimestamps),
  33       AllowASTWithErrors(AllowASTWithErrors),
  34       ShouldCacheASTInMemory(ShouldCacheASTInMemory) {
  35   this->Buffer->IsComplete = false;
  36 }
  37
  38 PCHGenerator::~PCHGenerator() {
  39 }
  40
  41 void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
  42   // Don't create a PCH if there were fatal failures during module loading.
  43   if (PP.getModuleLoader().HadFatalFailure)
  44     return;
  45
  46   bool hasErrors = PP.getDiagnostics().hasErrorOccurred();
  47   if (hasErrors && !AllowASTWithErrors)
  48     return;
  49
  50   Module *Module = nullptr;
  51   if (PP.getLangOpts().isCompilingModule()) {
  52     Module = PP.getHeaderSearchInfo().lookupModule(
  53         PP.getLangOpts().CurrentModule, SourceLocation(),
  54         /*AllowSearch*/ false);
  55     if (!Module) {
  56       assert(hasErrors && "emitting module but current module doesn't exist");
  57       return;
  58     }
  59   }
  60
  61   // Errors that do not prevent the PCH from being written should not cause the
  62   // overall compilation to fail either.
  63   if (AllowASTWithErrors)
  64     PP.getDiagnostics().getClient()->clear();
  65
  66   // Emit the PCH file to the Buffer.
  67   assert(SemaPtr && "No Sema?");
  68   Buffer->Signature =
  69       Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot,
  70                       // For serialization we are lenient if the errors were
  71                       // only warn-as-error kind.
  72                       PP.getDiagnostics().hasUncompilableErrorOccurred(),
  73                       ShouldCacheASTInMemory);
  74
  75   Buffer->IsComplete = true;
  76 }
  77
  78 ASTMutationListener *PCHGenerator::GetASTMutationListener() {
  79   return &Writer;
  80 }
  81
  82 ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
  83   return &Writer;
  84 }