ChainedIncludesSource.cpp revision 355940 
1//===- ChainedIncludesSource.cpp - Chained PCHs in Memory -------*- 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 ChainedIncludesSource class, which converts headers
10//  to chained PCHs in memory, mainly used for testing.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Basic/TargetInfo.h"
15#include "clang/Frontend/ASTUnit.h"
16#include "clang/Frontend/CompilerInstance.h"
17#include "clang/Frontend/TextDiagnosticPrinter.h"
18#include "clang/Lex/Preprocessor.h"
19#include "clang/Lex/PreprocessorOptions.h"
20#include "clang/Parse/ParseAST.h"
21#include "clang/Sema/MultiplexExternalSemaSource.h"
22#include "clang/Serialization/ASTReader.h"
23#include "clang/Serialization/ASTWriter.h"
24#include "llvm/Support/MemoryBuffer.h"
25
26using namespace clang;
27
28namespace {
29class ChainedIncludesSourceImpl : public ExternalSemaSource {
30public:
31  ChainedIncludesSourceImpl(std::vector<std::unique_ptr<CompilerInstance>> CIs)
32      : CIs(std::move(CIs)) {}
33
34protected:
35  //===----------------------------------------------------------------------===//
36  // ExternalASTSource interface.
37  //===----------------------------------------------------------------------===//
38
39  /// Return the amount of memory used by memory buffers, breaking down
40  /// by heap-backed versus mmap'ed memory.
41  void getMemoryBufferSizes(MemoryBufferSizes &sizes) const override {
42    for (unsigned i = 0, e = CIs.size(); i != e; ++i) {
43      if (const ExternalASTSource *eSrc =
44          CIs[i]->getASTContext().getExternalSource()) {
45        eSrc->getMemoryBufferSizes(sizes);
46      }
47    }
48  }
49
50private:
51  std::vector<std::unique_ptr<CompilerInstance>> CIs;
52};
53
54/// Members of ChainedIncludesSource, factored out so we can initialize
55/// them before we initialize the ExternalSemaSource base class.
56struct ChainedIncludesSourceMembers {
57  ChainedIncludesSourceMembers(
58      std::vector<std::unique_ptr<CompilerInstance>> CIs,
59      IntrusiveRefCntPtr<ExternalSemaSource> FinalReader)
60      : Impl(std::move(CIs)), FinalReader(std::move(FinalReader)) {}
61  ChainedIncludesSourceImpl Impl;
62  IntrusiveRefCntPtr<ExternalSemaSource> FinalReader;
63};
64
65/// Use MultiplexExternalSemaSource to dispatch all ExternalSemaSource
66/// calls to the final reader.
67class ChainedIncludesSource
68    : private ChainedIncludesSourceMembers,
69      public MultiplexExternalSemaSource {
70public:
71  ChainedIncludesSource(std::vector<std::unique_ptr<CompilerInstance>> CIs,
72                        IntrusiveRefCntPtr<ExternalSemaSource> FinalReader)
73      : ChainedIncludesSourceMembers(std::move(CIs), std::move(FinalReader)),
74        MultiplexExternalSemaSource(Impl, *this->FinalReader) {}
75};
76}
77
78static ASTReader *
79createASTReader(CompilerInstance &CI, StringRef pchFile,
80                SmallVectorImpl<std::unique_ptr<llvm::MemoryBuffer>> &MemBufs,
81                SmallVectorImpl<std::string> &bufNames,
82                ASTDeserializationListener *deserialListener = nullptr) {
83  Preprocessor &PP = CI.getPreprocessor();
84  std::unique_ptr<ASTReader> Reader;
85  Reader.reset(new ASTReader(PP, CI.getModuleCache(), &CI.getASTContext(),
86                             CI.getPCHContainerReader(),
87                             /*Extensions=*/{},
88                             /*isysroot=*/"", /*DisableValidation=*/true));
89  for (unsigned ti = 0; ti < bufNames.size(); ++ti) {
90    StringRef sr(bufNames[ti]);
91    Reader->addInMemoryBuffer(sr, std::move(MemBufs[ti]));
92  }
93  Reader->setDeserializationListener(deserialListener);
94  switch (Reader->ReadAST(pchFile, serialization::MK_PCH, SourceLocation(),
95                          ASTReader::ARR_None)) {
96  case ASTReader::Success:
97    // Set the predefines buffer as suggested by the PCH reader.
98    PP.setPredefines(Reader->getSuggestedPredefines());
99    return Reader.release();
100
101  case ASTReader::Failure:
102  case ASTReader::Missing:
103  case ASTReader::OutOfDate:
104  case ASTReader::VersionMismatch:
105  case ASTReader::ConfigurationMismatch:
106  case ASTReader::HadErrors:
107    break;
108  }
109  return nullptr;
110}
111
112IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
113    CompilerInstance &CI, IntrusiveRefCntPtr<ExternalSemaSource> &Reader) {
114
115  std::vector<std::string> &includes = CI.getPreprocessorOpts().ChainedIncludes;
116  assert(!includes.empty() && "No '-chain-include' in options!");
117
118  std::vector<std::unique_ptr<CompilerInstance>> CIs;
119  InputKind IK = CI.getFrontendOpts().Inputs[0].getKind();
120
121  SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 4> SerialBufs;
122  SmallVector<std::string, 4> serialBufNames;
123
124  for (unsigned i = 0, e = includes.size(); i != e; ++i) {
125    bool firstInclude = (i == 0);
126    std::unique_ptr<CompilerInvocation> CInvok;
127    CInvok.reset(new CompilerInvocation(CI.getInvocation()));
128
129    CInvok->getPreprocessorOpts().ChainedIncludes.clear();
130    CInvok->getPreprocessorOpts().ImplicitPCHInclude.clear();
131    CInvok->getPreprocessorOpts().DisablePCHValidation = true;
132    CInvok->getPreprocessorOpts().Includes.clear();
133    CInvok->getPreprocessorOpts().MacroIncludes.clear();
134    CInvok->getPreprocessorOpts().Macros.clear();
135
136    CInvok->getFrontendOpts().Inputs.clear();
137    FrontendInputFile InputFile(includes[i], IK);
138    CInvok->getFrontendOpts().Inputs.push_back(InputFile);
139
140    TextDiagnosticPrinter *DiagClient =
141      new TextDiagnosticPrinter(llvm::errs(), new DiagnosticOptions());
142    IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
143    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
144        new DiagnosticsEngine(DiagID, &CI.getDiagnosticOpts(), DiagClient));
145
146    std::unique_ptr<CompilerInstance> Clang(
147        new CompilerInstance(CI.getPCHContainerOperations()));
148    Clang->setInvocation(std::move(CInvok));
149    Clang->setDiagnostics(Diags.get());
150    Clang->setTarget(TargetInfo::CreateTargetInfo(
151        Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
152    Clang->createFileManager();
153    Clang->createSourceManager(Clang->getFileManager());
154    Clang->createPreprocessor(TU_Prefix);
155    Clang->getDiagnosticClient().BeginSourceFile(Clang->getLangOpts(),
156                                                 &Clang->getPreprocessor());
157    Clang->createASTContext();
158
159    auto Buffer = std::make_shared<PCHBuffer>();
160    ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions;
161    auto consumer = llvm::make_unique<PCHGenerator>(
162        Clang->getPreprocessor(), Clang->getModuleCache(), "-", /*isysroot=*/"",
163        Buffer, Extensions, /*AllowASTWithErrors=*/true);
164    Clang->getASTContext().setASTMutationListener(
165                                            consumer->GetASTMutationListener());
166    Clang->setASTConsumer(std::move(consumer));
167    Clang->createSema(TU_Prefix, nullptr);
168
169    if (firstInclude) {
170      Preprocessor &PP = Clang->getPreprocessor();
171      PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
172                                             PP.getLangOpts());
173    } else {
174      assert(!SerialBufs.empty());
175      SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 4> Bufs;
176      // TODO: Pass through the existing MemoryBuffer instances instead of
177      // allocating new ones.
178      for (auto &SB : SerialBufs)
179        Bufs.push_back(llvm::MemoryBuffer::getMemBuffer(SB->getBuffer()));
180      std::string pchName = includes[i-1];
181      llvm::raw_string_ostream os(pchName);
182      os << ".pch" << i-1;
183      serialBufNames.push_back(os.str());
184
185      IntrusiveRefCntPtr<ASTReader> Reader;
186      Reader = createASTReader(
187          *Clang, pchName, Bufs, serialBufNames,
188          Clang->getASTConsumer().GetASTDeserializationListener());
189      if (!Reader)
190        return nullptr;
191      Clang->setModuleManager(Reader);
192      Clang->getASTContext().setExternalSource(Reader);
193    }
194
195    if (!Clang->InitializeSourceManager(InputFile))
196      return nullptr;
197
198    ParseAST(Clang->getSema());
199    Clang->getDiagnosticClient().EndSourceFile();
200    assert(Buffer->IsComplete && "serialization did not complete");
201    auto &serialAST = Buffer->Data;
202    SerialBufs.push_back(llvm::MemoryBuffer::getMemBufferCopy(
203        StringRef(serialAST.data(), serialAST.size())));
204    serialAST.clear();
205    CIs.push_back(std::move(Clang));
206  }
207
208  assert(!SerialBufs.empty());
209  std::string pchName = includes.back() + ".pch-final";
210  serialBufNames.push_back(pchName);
211  Reader = createASTReader(CI, pchName, SerialBufs, serialBufNames);
212  if (!Reader)
213    return nullptr;
214
215  return IntrusiveRefCntPtr<ChainedIncludesSource>(
216      new ChainedIncludesSource(std::move(CIs), Reader));
217}
218