xref: /llvm-project/clang/lib/Frontend/ChainedIncludesSource.cpp (revision 21b3a032af8bcacbe2b3712de96b033b7ff3f208)
1 //===- ChainedIncludesSource.cpp - Chained PCHs in Memory -------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file defines the ChainedIncludesSource class, which converts headers
11 //  to chained PCHs in memory, mainly used for testing.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Basic/TargetInfo.h"
16 #include "clang/Frontend/ASTUnit.h"
17 #include "clang/Frontend/CompilerInstance.h"
18 #include "clang/Frontend/TextDiagnosticPrinter.h"
19 #include "clang/Lex/Preprocessor.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 
26 using namespace clang;
27 
28 namespace {
29 class ChainedIncludesSourceImpl : public ExternalSemaSource {
30 public:
31   ChainedIncludesSourceImpl(std::vector<std::unique_ptr<CompilerInstance>> CIs)
32       : CIs(std::move(CIs)) {}
33 
34 protected:
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 
50 private:
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.
56 struct ChainedIncludesSourceMembers {
57   ChainedIncludesSourceImpl Impl;
58   IntrusiveRefCntPtr<ExternalSemaSource> FinalReader;
59 };
60 
61 /// Use MultiplexExternalSemaSource to dispatch all ExternalSemaSource
62 /// calls to the final reader.
63 class ChainedIncludesSource
64     : private ChainedIncludesSourceMembers,
65       public MultiplexExternalSemaSource {
66 public:
67   ChainedIncludesSource(std::vector<std::unique_ptr<CompilerInstance>> CIs,
68                         IntrusiveRefCntPtr<ExternalSemaSource> FinalReader)
69       : ChainedIncludesSourceMembers{{std::move(CIs)}, std::move(FinalReader)},
70         MultiplexExternalSemaSource(Impl, *this->FinalReader) {}
71 };
72 }
73 
74 static ASTReader *
75 createASTReader(CompilerInstance &CI, StringRef pchFile,
76                 SmallVectorImpl<std::unique_ptr<llvm::MemoryBuffer>> &MemBufs,
77                 SmallVectorImpl<std::string> &bufNames,
78                 ASTDeserializationListener *deserialListener = nullptr) {
79   Preprocessor &PP = CI.getPreprocessor();
80   std::unique_ptr<ASTReader> Reader;
81   Reader.reset(new ASTReader(PP, CI.getASTContext(),
82                              CI.getPCHContainerReader(),
83                              /*Extensions=*/{ },
84                              /*isysroot=*/"", /*DisableValidation=*/true));
85   for (unsigned ti = 0; ti < bufNames.size(); ++ti) {
86     StringRef sr(bufNames[ti]);
87     Reader->addInMemoryBuffer(sr, std::move(MemBufs[ti]));
88   }
89   Reader->setDeserializationListener(deserialListener);
90   switch (Reader->ReadAST(pchFile, serialization::MK_PCH, SourceLocation(),
91                           ASTReader::ARR_None)) {
92   case ASTReader::Success:
93     // Set the predefines buffer as suggested by the PCH reader.
94     PP.setPredefines(Reader->getSuggestedPredefines());
95     return Reader.release();
96 
97   case ASTReader::Failure:
98   case ASTReader::Missing:
99   case ASTReader::OutOfDate:
100   case ASTReader::VersionMismatch:
101   case ASTReader::ConfigurationMismatch:
102   case ASTReader::HadErrors:
103     break;
104   }
105   return nullptr;
106 }
107 
108 IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
109     CompilerInstance &CI, IntrusiveRefCntPtr<ExternalSemaSource> &Reader) {
110 
111   std::vector<std::string> &includes = CI.getPreprocessorOpts().ChainedIncludes;
112   assert(!includes.empty() && "No '-chain-include' in options!");
113 
114   std::vector<std::unique_ptr<CompilerInstance>> CIs;
115   InputKind IK = CI.getFrontendOpts().Inputs[0].getKind();
116 
117   SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 4> SerialBufs;
118   SmallVector<std::string, 4> serialBufNames;
119 
120   for (unsigned i = 0, e = includes.size(); i != e; ++i) {
121     bool firstInclude = (i == 0);
122     std::unique_ptr<CompilerInvocation> CInvok;
123     CInvok.reset(new CompilerInvocation(CI.getInvocation()));
124 
125     CInvok->getPreprocessorOpts().ChainedIncludes.clear();
126     CInvok->getPreprocessorOpts().ImplicitPCHInclude.clear();
127     CInvok->getPreprocessorOpts().ImplicitPTHInclude.clear();
128     CInvok->getPreprocessorOpts().DisablePCHValidation = true;
129     CInvok->getPreprocessorOpts().Includes.clear();
130     CInvok->getPreprocessorOpts().MacroIncludes.clear();
131     CInvok->getPreprocessorOpts().Macros.clear();
132 
133     CInvok->getFrontendOpts().Inputs.clear();
134     FrontendInputFile InputFile(includes[i], IK);
135     CInvok->getFrontendOpts().Inputs.push_back(InputFile);
136 
137     TextDiagnosticPrinter *DiagClient =
138       new TextDiagnosticPrinter(llvm::errs(), new DiagnosticOptions());
139     IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
140     IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
141         new DiagnosticsEngine(DiagID, &CI.getDiagnosticOpts(), DiagClient));
142 
143     std::unique_ptr<CompilerInstance> Clang(
144         new CompilerInstance(CI.getPCHContainerOperations()));
145     Clang->setInvocation(CInvok.release());
146     Clang->setDiagnostics(Diags.get());
147     Clang->setTarget(TargetInfo::CreateTargetInfo(
148         Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
149     Clang->createFileManager();
150     Clang->createSourceManager(Clang->getFileManager());
151     Clang->createPreprocessor(TU_Prefix);
152     Clang->getDiagnosticClient().BeginSourceFile(Clang->getLangOpts(),
153                                                  &Clang->getPreprocessor());
154     Clang->createASTContext();
155 
156     auto Buffer = std::make_shared<PCHBuffer>();
157     ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions;
158     auto consumer = llvm::make_unique<PCHGenerator>(
159         Clang->getPreprocessor(), "-", nullptr, /*isysroot=*/"", Buffer,
160         Extensions, /*AllowASTWithErrors=*/true);
161     Clang->getASTContext().setASTMutationListener(
162                                             consumer->GetASTMutationListener());
163     Clang->setASTConsumer(std::move(consumer));
164     Clang->createSema(TU_Prefix, nullptr);
165 
166     if (firstInclude) {
167       Preprocessor &PP = Clang->getPreprocessor();
168       PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
169                                              PP.getLangOpts());
170     } else {
171       assert(!SerialBufs.empty());
172       SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 4> Bufs;
173       // TODO: Pass through the existing MemoryBuffer instances instead of
174       // allocating new ones.
175       for (auto &SB : SerialBufs)
176         Bufs.push_back(llvm::MemoryBuffer::getMemBuffer(SB->getBuffer()));
177       std::string pchName = includes[i-1];
178       llvm::raw_string_ostream os(pchName);
179       os << ".pch" << i-1;
180       serialBufNames.push_back(os.str());
181 
182       IntrusiveRefCntPtr<ASTReader> Reader;
183       Reader = createASTReader(
184           *Clang, pchName, Bufs, serialBufNames,
185           Clang->getASTConsumer().GetASTDeserializationListener());
186       if (!Reader)
187         return nullptr;
188       Clang->setModuleManager(Reader);
189       Clang->getASTContext().setExternalSource(Reader);
190     }
191 
192     if (!Clang->InitializeSourceManager(InputFile))
193       return nullptr;
194 
195     ParseAST(Clang->getSema());
196     Clang->getDiagnosticClient().EndSourceFile();
197     assert(Buffer->IsComplete && "serialization did not complete");
198     auto &serialAST = Buffer->Data;
199     SerialBufs.push_back(llvm::MemoryBuffer::getMemBufferCopy(
200         StringRef(serialAST.data(), serialAST.size())));
201     serialAST.clear();
202     CIs.push_back(std::move(Clang));
203   }
204 
205   assert(!SerialBufs.empty());
206   std::string pchName = includes.back() + ".pch-final";
207   serialBufNames.push_back(pchName);
208   Reader = createASTReader(CI, pchName, SerialBufs, serialBufNames);
209   if (!Reader)
210     return nullptr;
211 
212   return IntrusiveRefCntPtr<ChainedIncludesSource>(
213       new ChainedIncludesSource(std::move(CIs), Reader));
214 }
215