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