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, /*AllowSearch*/ false);
54     if (!Module) {
55       assert(hasErrors && "emitting module but current module doesn't exist");
56       return;
57     }
58   }
59 
60   // Emit the PCH file to the Buffer.
61   assert(SemaPtr && "No Sema?");
62   Buffer->Signature =
63       Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot,
64                       // For serialization we are lenient if the errors were
65                       // only warn-as-error kind.
66                       PP.getDiagnostics().hasUncompilableErrorOccurred(),
67                       ShouldCacheASTInMemory);
68 
69   Buffer->IsComplete = true;
70 }
71 
72 ASTMutationListener *PCHGenerator::GetASTMutationListener() {
73   return &Writer;
74 }
75 
76 ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
77   return &Writer;
78 }
79