llvm-project

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//===- Preprocessor.cpp - C Language Family Preprocessor Implementation ---===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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//  This file implements the Preprocessor interface.
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//
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//===----------------------------------------------------------------------===//
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//
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// Options to support:
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//   -H       - Print the name of each header file used.
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//   -d[DNI] - Dump various things.
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//   -fworking-directory - #line's with preprocessor's working dir.
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//   -fpreprocessed
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//   -dependency-file,-M,-MM,-MF,-MG,-MP,-MT,-MQ,-MD,-MMD
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//   -W*
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//   -w
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//
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// Messages to emit:
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//   "Multiple include guards may be useful for:\n"
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Lex/Preprocessor.h"
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#include "clang/Basic/Builtins.h"
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#include "clang/Basic/FileManager.h"
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#include "clang/Basic/FileSystemStatCache.h"
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#include "clang/Basic/IdentifierTable.h"
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#include "clang/Basic/LLVM.h"
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#include "clang/Basic/LangOptions.h"
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#include "clang/Basic/Module.h"
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#include "clang/Basic/SourceLocation.h"
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#include "clang/Basic/SourceManager.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/Lex/CodeCompletionHandler.h"
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#include "clang/Lex/ExternalPreprocessorSource.h"
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#include "clang/Lex/HeaderSearch.h"
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#include "clang/Lex/LexDiagnostic.h"
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#include "clang/Lex/Lexer.h"
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#include "clang/Lex/LiteralSupport.h"
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#include "clang/Lex/MacroArgs.h"
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#include "clang/Lex/MacroInfo.h"
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#include "clang/Lex/ModuleLoader.h"
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#include "clang/Lex/Pragma.h"
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#include "clang/Lex/PreprocessingRecord.h"
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#include "clang/Lex/PreprocessorLexer.h"
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#include "clang/Lex/PreprocessorOptions.h"
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#include "clang/Lex/ScratchBuffer.h"
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#include "clang/Lex/Token.h"
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#include "clang/Lex/TokenLexer.h"
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#include "llvm/ADT/APInt.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/ADT/iterator_range.h"
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#include "llvm/Support/Capacity.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/raw_ostream.h"
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#include <algorithm>
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#include <cassert>
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#include <memory>
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#include <optional>
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#include <string>
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#include <utility>
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#include <vector>
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using namespace clang;
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/// Minimum distance between two check points, in tokens.
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static constexpr unsigned CheckPointStepSize = 1024;
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LLVM_INSTANTIATE_REGISTRY(PragmaHandlerRegistry)
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ExternalPreprocessorSource::~ExternalPreprocessorSource() = default;
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Preprocessor::Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts,
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                           DiagnosticsEngine &diags, const LangOptions &opts,
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                           SourceManager &SM, HeaderSearch &Headers,
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                           ModuleLoader &TheModuleLoader,
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                           IdentifierInfoLookup *IILookup, bool OwnsHeaders,
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                           TranslationUnitKind TUKind)
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    : PPOpts(std::move(PPOpts)), Diags(&diags), LangOpts(opts),
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      FileMgr(Headers.getFileMgr()), SourceMgr(SM),
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      ScratchBuf(new ScratchBuffer(SourceMgr)), HeaderInfo(Headers),
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      TheModuleLoader(TheModuleLoader), ExternalSource(nullptr),
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      // As the language options may have not been loaded yet (when
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      // deserializing an ASTUnit), adding keywords to the identifier table is
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      // deferred to Preprocessor::Initialize().
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      Identifiers(IILookup), PragmaHandlers(new PragmaNamespace(StringRef())),
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      TUKind(TUKind), SkipMainFilePreamble(0, true),
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      CurSubmoduleState(&NullSubmoduleState) {
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  OwnsHeaderSearch = OwnsHeaders;
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  // Default to discarding comments.
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  KeepComments = false;
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  KeepMacroComments = false;
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  SuppressIncludeNotFoundError = false;
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  // Macro expansion is enabled.
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  DisableMacroExpansion = false;
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  MacroExpansionInDirectivesOverride = false;
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  InMacroArgs = false;
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  ArgMacro = nullptr;
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  InMacroArgPreExpansion = false;
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  NumCachedTokenLexers = 0;
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  PragmasEnabled = true;
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  ParsingIfOrElifDirective = false;
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  PreprocessedOutput = false;
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  // We haven't read anything from the external source.
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  ReadMacrosFromExternalSource = false;
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  BuiltinInfo = std::make_unique<Builtin::Context>();
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  // "Poison" __VA_ARGS__, __VA_OPT__ which can only appear in the expansion of
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  // a macro. They get unpoisoned where it is allowed.
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  (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
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  SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use);
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  (Ident__VA_OPT__ = getIdentifierInfo("__VA_OPT__"))->setIsPoisoned();
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  SetPoisonReason(Ident__VA_OPT__,diag::ext_pp_bad_vaopt_use);
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  // Initialize the pragma handlers.
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  RegisterBuiltinPragmas();
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  // Initialize builtin macros like __LINE__ and friends.
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  RegisterBuiltinMacros();
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  if(LangOpts.Borland) {
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    Ident__exception_info        = getIdentifierInfo("_exception_info");
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    Ident___exception_info       = getIdentifierInfo("__exception_info");
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    Ident_GetExceptionInfo       = getIdentifierInfo("GetExceptionInformation");
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    Ident__exception_code        = getIdentifierInfo("_exception_code");
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    Ident___exception_code       = getIdentifierInfo("__exception_code");
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    Ident_GetExceptionCode       = getIdentifierInfo("GetExceptionCode");
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    Ident__abnormal_termination  = getIdentifierInfo("_abnormal_termination");
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    Ident___abnormal_termination = getIdentifierInfo("__abnormal_termination");
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    Ident_AbnormalTermination    = getIdentifierInfo("AbnormalTermination");
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  } else {
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    Ident__exception_info = Ident__exception_code = nullptr;
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    Ident__abnormal_termination = Ident___exception_info = nullptr;
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    Ident___exception_code = Ident___abnormal_termination = nullptr;
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    Ident_GetExceptionInfo = Ident_GetExceptionCode = nullptr;
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    Ident_AbnormalTermination = nullptr;
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  }
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  // Default incremental processing to -fincremental-extensions, clients can
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  // override with `enableIncrementalProcessing` if desired.
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  IncrementalProcessing = LangOpts.IncrementalExtensions;
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  // If using a PCH where a #pragma hdrstop is expected, start skipping tokens.
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  if (usingPCHWithPragmaHdrStop())
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    SkippingUntilPragmaHdrStop = true;
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  // If using a PCH with a through header, start skipping tokens.
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  if (!this->PPOpts->PCHThroughHeader.empty() &&
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      !this->PPOpts->ImplicitPCHInclude.empty())
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    SkippingUntilPCHThroughHeader = true;
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  if (this->PPOpts->GeneratePreamble)
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    PreambleConditionalStack.startRecording();
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  MaxTokens = LangOpts.MaxTokens;
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}
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Preprocessor::~Preprocessor() {
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  assert(BacktrackPositions.empty() && "EnableBacktrack/Backtrack imbalance!");
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  IncludeMacroStack.clear();
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  // Free any cached macro expanders.
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  // This populates MacroArgCache, so all TokenLexers need to be destroyed
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  // before the code below that frees up the MacroArgCache list.
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  std::fill(TokenLexerCache, TokenLexerCache + NumCachedTokenLexers, nullptr);
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  CurTokenLexer.reset();
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  // Free any cached MacroArgs.
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  for (MacroArgs *ArgList = MacroArgCache; ArgList;)
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    ArgList = ArgList->deallocate();
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  // Delete the header search info, if we own it.
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  if (OwnsHeaderSearch)
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    delete &HeaderInfo;
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}
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void Preprocessor::Initialize(const TargetInfo &Target,
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                              const TargetInfo *AuxTarget) {
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  assert((!this->Target || this->Target == &Target) &&
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         "Invalid override of target information");
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  this->Target = &Target;
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  assert((!this->AuxTarget || this->AuxTarget == AuxTarget) &&
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         "Invalid override of aux target information.");
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  this->AuxTarget = AuxTarget;
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  // Initialize information about built-ins.
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  BuiltinInfo->InitializeTarget(Target, AuxTarget);
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  HeaderInfo.setTarget(Target);
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  // Populate the identifier table with info about keywords for the current language.
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  Identifiers.AddKeywords(LangOpts);
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  // Initialize the __FTL_EVAL_METHOD__ macro to the TargetInfo.
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  setTUFPEvalMethod(getTargetInfo().getFPEvalMethod());
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  if (getLangOpts().getFPEvalMethod() == LangOptions::FEM_UnsetOnCommandLine)
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    // Use setting from TargetInfo.
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    setCurrentFPEvalMethod(SourceLocation(), Target.getFPEvalMethod());
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  else
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    // Set initial value of __FLT_EVAL_METHOD__ from the command line.
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    setCurrentFPEvalMethod(SourceLocation(), getLangOpts().getFPEvalMethod());
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}
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void Preprocessor::InitializeForModelFile() {
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  NumEnteredSourceFiles = 0;
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  // Reset pragmas
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  PragmaHandlersBackup = std::move(PragmaHandlers);
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  PragmaHandlers = std::make_unique<PragmaNamespace>(StringRef());
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  RegisterBuiltinPragmas();
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  // Reset PredefinesFileID
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  PredefinesFileID = FileID();
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}
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void Preprocessor::FinalizeForModelFile() {
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  NumEnteredSourceFiles = 1;
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  PragmaHandlers = std::move(PragmaHandlersBackup);
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}
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void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
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  llvm::errs() << tok::getTokenName(Tok.getKind());
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  if (!Tok.isAnnotation())
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    llvm::errs() << " '" << getSpelling(Tok) << "'";
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  if (!DumpFlags) return;
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  llvm::errs() << "\t";
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  if (Tok.isAtStartOfLine())
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    llvm::errs() << " [StartOfLine]";
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  if (Tok.hasLeadingSpace())
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    llvm::errs() << " [LeadingSpace]";
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  if (Tok.isExpandDisabled())
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    llvm::errs() << " [ExpandDisabled]";
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  if (Tok.needsCleaning()) {
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    const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
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    llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength())
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                 << "']";
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  }
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  llvm::errs() << "\tLoc=<";
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  DumpLocation(Tok.getLocation());
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  llvm::errs() << ">";
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}
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void Preprocessor::DumpLocation(SourceLocation Loc) const {
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  Loc.print(llvm::errs(), SourceMgr);
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}
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void Preprocessor::DumpMacro(const MacroInfo &MI) const {
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  llvm::errs() << "MACRO: ";
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  for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
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    DumpToken(MI.getReplacementToken(i));
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    llvm::errs() << "  ";
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  }
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  llvm::errs() << "\n";
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}
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void Preprocessor::PrintStats() {
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  llvm::errs() << "\n*** Preprocessor Stats:\n";
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  llvm::errs() << NumDirectives << " directives found:\n";
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  llvm::errs() << "  " << NumDefined << " #define.\n";
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  llvm::errs() << "  " << NumUndefined << " #undef.\n";
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  llvm::errs() << "  #include/#include_next/#import:\n";
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  llvm::errs() << "    " << NumEnteredSourceFiles << " source files entered.\n";
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  llvm::errs() << "    " << MaxIncludeStackDepth << " max include stack depth\n";
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  llvm::errs() << "  " << NumIf << " #if/#ifndef/#ifdef.\n";
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  llvm::errs() << "  " << NumElse << " #else/#elif/#elifdef/#elifndef.\n";
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  llvm::errs() << "  " << NumEndif << " #endif.\n";
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  llvm::errs() << "  " << NumPragma << " #pragma.\n";
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  llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
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  llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
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             << NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
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             << NumFastMacroExpanded << " on the fast path.\n";
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  llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
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             << " token paste (##) operations performed, "
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             << NumFastTokenPaste << " on the fast path.\n";
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  llvm::errs() << "\nPreprocessor Memory: " << getTotalMemory() << "B total";
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  llvm::errs() << "\n  BumpPtr: " << BP.getTotalMemory();
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  llvm::errs() << "\n  Macro Expanded Tokens: "
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               << llvm::capacity_in_bytes(MacroExpandedTokens);
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  llvm::errs() << "\n  Predefines Buffer: " << Predefines.capacity();
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  // FIXME: List information for all submodules.
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  llvm::errs() << "\n  Macros: "
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               << llvm::capacity_in_bytes(CurSubmoduleState->Macros);
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  llvm::errs() << "\n  #pragma push_macro Info: "
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               << llvm::capacity_in_bytes(PragmaPushMacroInfo);
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  llvm::errs() << "\n  Poison Reasons: "
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               << llvm::capacity_in_bytes(PoisonReasons);
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  llvm::errs() << "\n  Comment Handlers: "
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               << llvm::capacity_in_bytes(CommentHandlers) << "\n";
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}
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Preprocessor::macro_iterator
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Preprocessor::macro_begin(bool IncludeExternalMacros) const {
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  if (IncludeExternalMacros && ExternalSource &&
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      !ReadMacrosFromExternalSource) {
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    ReadMacrosFromExternalSource = true;
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    ExternalSource->ReadDefinedMacros();
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  }
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  // Make sure we cover all macros in visible modules.
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  for (const ModuleMacro &Macro : ModuleMacros)
325
    CurSubmoduleState->Macros.insert(std::make_pair(Macro.II, MacroState()));
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327
  return CurSubmoduleState->Macros.begin();
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}
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size_t Preprocessor::getTotalMemory() const {
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  return BP.getTotalMemory()
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    + llvm::capacity_in_bytes(MacroExpandedTokens)
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    + Predefines.capacity() /* Predefines buffer. */
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    // FIXME: Include sizes from all submodules, and include MacroInfo sizes,
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    // and ModuleMacros.
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    + llvm::capacity_in_bytes(CurSubmoduleState->Macros)
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    + llvm::capacity_in_bytes(PragmaPushMacroInfo)
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    + llvm::capacity_in_bytes(PoisonReasons)
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    + llvm::capacity_in_bytes(CommentHandlers);
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}
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Preprocessor::macro_iterator
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Preprocessor::macro_end(bool IncludeExternalMacros) const {
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  if (IncludeExternalMacros && ExternalSource &&
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      !ReadMacrosFromExternalSource) {
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    ReadMacrosFromExternalSource = true;
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    ExternalSource->ReadDefinedMacros();
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  }
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350
  return CurSubmoduleState->Macros.end();
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}
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/// Compares macro tokens with a specified token value sequence.
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static bool MacroDefinitionEquals(const MacroInfo *MI,
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                                  ArrayRef<TokenValue> Tokens) {
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  return Tokens.size() == MI->getNumTokens() &&
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      std::equal(Tokens.begin(), Tokens.end(), MI->tokens_begin());
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}
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StringRef Preprocessor::getLastMacroWithSpelling(
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                                    SourceLocation Loc,
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                                    ArrayRef<TokenValue> Tokens) const {
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  SourceLocation BestLocation;
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  StringRef BestSpelling;
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  for (Preprocessor::macro_iterator I = macro_begin(), E = macro_end();
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       I != E; ++I) {
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    const MacroDirective::DefInfo
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      Def = I->second.findDirectiveAtLoc(Loc, SourceMgr);
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    if (!Def || !Def.getMacroInfo())
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      continue;
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    if (!Def.getMacroInfo()->isObjectLike())
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      continue;
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    if (!MacroDefinitionEquals(Def.getMacroInfo(), Tokens))
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      continue;
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    SourceLocation Location = Def.getLocation();
376
    // Choose the macro defined latest.
377
    if (BestLocation.isInvalid() ||
378
        (Location.isValid() &&
379
         SourceMgr.isBeforeInTranslationUnit(BestLocation, Location))) {
380
      BestLocation = Location;
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      BestSpelling = I->first->getName();
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    }
383
  }
384
  return BestSpelling;
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}
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void Preprocessor::recomputeCurLexerKind() {
388
  if (CurLexer)
389
    CurLexerCallback = CurLexer->isDependencyDirectivesLexer()
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                           ? CLK_DependencyDirectivesLexer
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                           : CLK_Lexer;
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  else if (CurTokenLexer)
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    CurLexerCallback = CLK_TokenLexer;
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  else
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    CurLexerCallback = CLK_CachingLexer;
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}
397

398
bool Preprocessor::SetCodeCompletionPoint(FileEntryRef File,
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                                          unsigned CompleteLine,
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                                          unsigned CompleteColumn) {
401
  assert(CompleteLine && CompleteColumn && "Starts from 1:1");
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  assert(!CodeCompletionFile && "Already set");
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404
  // Load the actual file's contents.
405
  std::optional<llvm::MemoryBufferRef> Buffer =
406
      SourceMgr.getMemoryBufferForFileOrNone(File);
407
  if (!Buffer)
408
    return true;
409

410
  // Find the byte position of the truncation point.
411
  const char *Position = Buffer->getBufferStart();
412
  for (unsigned Line = 1; Line < CompleteLine; ++Line) {
413
    for (; *Position; ++Position) {
414
      if (*Position != '\r' && *Position != '\n')
415
        continue;
416

417
      // Eat \r\n or \n\r as a single line.
418
      if ((Position[1] == '\r' || Position[1] == '\n') &&
419
          Position[0] != Position[1])
420
        ++Position;
421
      ++Position;
422
      break;
423
    }
424
  }
425

426
  Position += CompleteColumn - 1;
427

428
  // If pointing inside the preamble, adjust the position at the beginning of
429
  // the file after the preamble.
430
  if (SkipMainFilePreamble.first &&
431
      SourceMgr.getFileEntryForID(SourceMgr.getMainFileID()) == File) {
432
    if (Position - Buffer->getBufferStart() < SkipMainFilePreamble.first)
433
      Position = Buffer->getBufferStart() + SkipMainFilePreamble.first;
434
  }
435

436
  if (Position > Buffer->getBufferEnd())
437
    Position = Buffer->getBufferEnd();
438

439
  CodeCompletionFile = File;
440
  CodeCompletionOffset = Position - Buffer->getBufferStart();
441

442
  auto NewBuffer = llvm::WritableMemoryBuffer::getNewUninitMemBuffer(
443
      Buffer->getBufferSize() + 1, Buffer->getBufferIdentifier());
444
  char *NewBuf = NewBuffer->getBufferStart();
445
  char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
446
  *NewPos = '\0';
447
  std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
448
  SourceMgr.overrideFileContents(File, std::move(NewBuffer));
449

450
  return false;
451
}
452

453
void Preprocessor::CodeCompleteIncludedFile(llvm::StringRef Dir,
454
                                            bool IsAngled) {
455
  setCodeCompletionReached();
456
  if (CodeComplete)
457
    CodeComplete->CodeCompleteIncludedFile(Dir, IsAngled);
458
}
459

460
void Preprocessor::CodeCompleteNaturalLanguage() {
461
  setCodeCompletionReached();
462
  if (CodeComplete)
463
    CodeComplete->CodeCompleteNaturalLanguage();
464
}
465

466
/// getSpelling - This method is used to get the spelling of a token into a
467
/// SmallVector. Note that the returned StringRef may not point to the
468
/// supplied buffer if a copy can be avoided.
469
StringRef Preprocessor::getSpelling(const Token &Tok,
470
                                          SmallVectorImpl<char> &Buffer,
471
                                          bool *Invalid) const {
472
  // NOTE: this has to be checked *before* testing for an IdentifierInfo.
473
  if (Tok.isNot(tok::raw_identifier) && !Tok.hasUCN()) {
474
    // Try the fast path.
475
    if (const IdentifierInfo *II = Tok.getIdentifierInfo())
476
      return II->getName();
477
  }
478

479
  // Resize the buffer if we need to copy into it.
480
  if (Tok.needsCleaning())
481
    Buffer.resize(Tok.getLength());
482

483
  const char *Ptr = Buffer.data();
484
  unsigned Len = getSpelling(Tok, Ptr, Invalid);
485
  return StringRef(Ptr, Len);
486
}
487

488
/// CreateString - Plop the specified string into a scratch buffer and return a
489
/// location for it.  If specified, the source location provides a source
490
/// location for the token.
491
void Preprocessor::CreateString(StringRef Str, Token &Tok,
492
                                SourceLocation ExpansionLocStart,
493
                                SourceLocation ExpansionLocEnd) {
494
  Tok.setLength(Str.size());
495

496
  const char *DestPtr;
497
  SourceLocation Loc = ScratchBuf->getToken(Str.data(), Str.size(), DestPtr);
498

499
  if (ExpansionLocStart.isValid())
500
    Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
501
                                       ExpansionLocEnd, Str.size());
502
  Tok.setLocation(Loc);
503

504
  // If this is a raw identifier or a literal token, set the pointer data.
505
  if (Tok.is(tok::raw_identifier))
506
    Tok.setRawIdentifierData(DestPtr);
507
  else if (Tok.isLiteral())
508
    Tok.setLiteralData(DestPtr);
509
}
510

511
SourceLocation Preprocessor::SplitToken(SourceLocation Loc, unsigned Length) {
512
  auto &SM = getSourceManager();
513
  SourceLocation SpellingLoc = SM.getSpellingLoc(Loc);
514
  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(SpellingLoc);
515
  bool Invalid = false;
516
  StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
517
  if (Invalid)
518
    return SourceLocation();
519

520
  // FIXME: We could consider re-using spelling for tokens we see repeatedly.
521
  const char *DestPtr;
522
  SourceLocation Spelling =
523
      ScratchBuf->getToken(Buffer.data() + LocInfo.second, Length, DestPtr);
524
  return SM.createTokenSplitLoc(Spelling, Loc, Loc.getLocWithOffset(Length));
525
}
526

527
Module *Preprocessor::getCurrentModule() {
528
  if (!getLangOpts().isCompilingModule())
529
    return nullptr;
530

531
  return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
532
}
533

534
Module *Preprocessor::getCurrentModuleImplementation() {
535
  if (!getLangOpts().isCompilingModuleImplementation())
536
    return nullptr;
537

538
  return getHeaderSearchInfo().lookupModule(getLangOpts().ModuleName);
539
}
540

541
//===----------------------------------------------------------------------===//
542
// Preprocessor Initialization Methods
543
//===----------------------------------------------------------------------===//
544

545
/// EnterMainSourceFile - Enter the specified FileID as the main source file,
546
/// which implicitly adds the builtin defines etc.
547
void Preprocessor::EnterMainSourceFile() {
548
  // We do not allow the preprocessor to reenter the main file.  Doing so will
549
  // cause FileID's to accumulate information from both runs (e.g. #line
550
  // information) and predefined macros aren't guaranteed to be set properly.
551
  assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
552
  FileID MainFileID = SourceMgr.getMainFileID();
553

554
  // If MainFileID is loaded it means we loaded an AST file, no need to enter
555
  // a main file.
556
  if (!SourceMgr.isLoadedFileID(MainFileID)) {
557
    // Enter the main file source buffer.
558
    EnterSourceFile(MainFileID, nullptr, SourceLocation());
559

560
    // If we've been asked to skip bytes in the main file (e.g., as part of a
561
    // precompiled preamble), do so now.
562
    if (SkipMainFilePreamble.first > 0)
563
      CurLexer->SetByteOffset(SkipMainFilePreamble.first,
564
                              SkipMainFilePreamble.second);
565

566
    // Tell the header info that the main file was entered.  If the file is later
567
    // #imported, it won't be re-entered.
568
    if (OptionalFileEntryRef FE = SourceMgr.getFileEntryRefForID(MainFileID))
569
      markIncluded(*FE);
570
  }
571

572
  // Preprocess Predefines to populate the initial preprocessor state.
573
  std::unique_ptr<llvm::MemoryBuffer> SB =
574
    llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
575
  assert(SB && "Cannot create predefined source buffer");
576
  FileID FID = SourceMgr.createFileID(std::move(SB));
577
  assert(FID.isValid() && "Could not create FileID for predefines?");
578
  setPredefinesFileID(FID);
579

580
  // Start parsing the predefines.
581
  EnterSourceFile(FID, nullptr, SourceLocation());
582

583
  if (!PPOpts->PCHThroughHeader.empty()) {
584
    // Lookup and save the FileID for the through header. If it isn't found
585
    // in the search path, it's a fatal error.
586
    OptionalFileEntryRef File = LookupFile(
587
        SourceLocation(), PPOpts->PCHThroughHeader,
588
        /*isAngled=*/false, /*FromDir=*/nullptr, /*FromFile=*/nullptr,
589
        /*CurDir=*/nullptr, /*SearchPath=*/nullptr, /*RelativePath=*/nullptr,
590
        /*SuggestedModule=*/nullptr, /*IsMapped=*/nullptr,
591
        /*IsFrameworkFound=*/nullptr);
592
    if (!File) {
593
      Diag(SourceLocation(), diag::err_pp_through_header_not_found)
594
          << PPOpts->PCHThroughHeader;
595
      return;
596
    }
597
    setPCHThroughHeaderFileID(
598
        SourceMgr.createFileID(*File, SourceLocation(), SrcMgr::C_User));
599
  }
600

601
  // Skip tokens from the Predefines and if needed the main file.
602
  if ((usingPCHWithThroughHeader() && SkippingUntilPCHThroughHeader) ||
603
      (usingPCHWithPragmaHdrStop() && SkippingUntilPragmaHdrStop))
604
    SkipTokensWhileUsingPCH();
605
}
606

607
void Preprocessor::setPCHThroughHeaderFileID(FileID FID) {
608
  assert(PCHThroughHeaderFileID.isInvalid() &&
609
         "PCHThroughHeaderFileID already set!");
610
  PCHThroughHeaderFileID = FID;
611
}
612

613
bool Preprocessor::isPCHThroughHeader(const FileEntry *FE) {
614
  assert(PCHThroughHeaderFileID.isValid() &&
615
         "Invalid PCH through header FileID");
616
  return FE == SourceMgr.getFileEntryForID(PCHThroughHeaderFileID);
617
}
618

619
bool Preprocessor::creatingPCHWithThroughHeader() {
620
  return TUKind == TU_Prefix && !PPOpts->PCHThroughHeader.empty() &&
621
         PCHThroughHeaderFileID.isValid();
622
}
623

624
bool Preprocessor::usingPCHWithThroughHeader() {
625
  return TUKind != TU_Prefix && !PPOpts->PCHThroughHeader.empty() &&
626
         PCHThroughHeaderFileID.isValid();
627
}
628

629
bool Preprocessor::creatingPCHWithPragmaHdrStop() {
630
  return TUKind == TU_Prefix && PPOpts->PCHWithHdrStop;
631
}
632

633
bool Preprocessor::usingPCHWithPragmaHdrStop() {
634
  return TUKind != TU_Prefix && PPOpts->PCHWithHdrStop;
635
}
636

637
/// Skip tokens until after the #include of the through header or
638
/// until after a #pragma hdrstop is seen. Tokens in the predefines file
639
/// and the main file may be skipped. If the end of the predefines file
640
/// is reached, skipping continues into the main file. If the end of the
641
/// main file is reached, it's a fatal error.
642
void Preprocessor::SkipTokensWhileUsingPCH() {
643
  bool ReachedMainFileEOF = false;
644
  bool UsingPCHThroughHeader = SkippingUntilPCHThroughHeader;
645
  bool UsingPragmaHdrStop = SkippingUntilPragmaHdrStop;
646
  Token Tok;
647
  while (true) {
648
    bool InPredefines =
649
        (CurLexer && CurLexer->getFileID() == getPredefinesFileID());
650
    CurLexerCallback(*this, Tok);
651
    if (Tok.is(tok::eof) && !InPredefines) {
652
      ReachedMainFileEOF = true;
653
      break;
654
    }
655
    if (UsingPCHThroughHeader && !SkippingUntilPCHThroughHeader)
656
      break;
657
    if (UsingPragmaHdrStop && !SkippingUntilPragmaHdrStop)
658
      break;
659
  }
660
  if (ReachedMainFileEOF) {
661
    if (UsingPCHThroughHeader)
662
      Diag(SourceLocation(), diag::err_pp_through_header_not_seen)
663
          << PPOpts->PCHThroughHeader << 1;
664
    else if (!PPOpts->PCHWithHdrStopCreate)
665
      Diag(SourceLocation(), diag::err_pp_pragma_hdrstop_not_seen);
666
  }
667
}
668

669
void Preprocessor::replayPreambleConditionalStack() {
670
  // Restore the conditional stack from the preamble, if there is one.
671
  if (PreambleConditionalStack.isReplaying()) {
672
    assert(CurPPLexer &&
673
           "CurPPLexer is null when calling replayPreambleConditionalStack.");
674
    CurPPLexer->setConditionalLevels(PreambleConditionalStack.getStack());
675
    PreambleConditionalStack.doneReplaying();
676
    if (PreambleConditionalStack.reachedEOFWhileSkipping())
677
      SkipExcludedConditionalBlock(
678
          PreambleConditionalStack.SkipInfo->HashTokenLoc,
679
          PreambleConditionalStack.SkipInfo->IfTokenLoc,
680
          PreambleConditionalStack.SkipInfo->FoundNonSkipPortion,
681
          PreambleConditionalStack.SkipInfo->FoundElse,
682
          PreambleConditionalStack.SkipInfo->ElseLoc);
683
  }
684
}
685

686
void Preprocessor::EndSourceFile() {
687
  // Notify the client that we reached the end of the source file.
688
  if (Callbacks)
689
    Callbacks->EndOfMainFile();
690
}
691

692
//===----------------------------------------------------------------------===//
693
// Lexer Event Handling.
694
//===----------------------------------------------------------------------===//
695

696
/// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
697
/// identifier information for the token and install it into the token,
698
/// updating the token kind accordingly.
699
IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
700
  assert(!Identifier.getRawIdentifier().empty() && "No raw identifier data!");
701

702
  // Look up this token, see if it is a macro, or if it is a language keyword.
703
  IdentifierInfo *II;
704
  if (!Identifier.needsCleaning() && !Identifier.hasUCN()) {
705
    // No cleaning needed, just use the characters from the lexed buffer.
706
    II = getIdentifierInfo(Identifier.getRawIdentifier());
707
  } else {
708
    // Cleaning needed, alloca a buffer, clean into it, then use the buffer.
709
    SmallString<64> IdentifierBuffer;
710
    StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
711

712
    if (Identifier.hasUCN()) {
713
      SmallString<64> UCNIdentifierBuffer;
714
      expandUCNs(UCNIdentifierBuffer, CleanedStr);
715
      II = getIdentifierInfo(UCNIdentifierBuffer);
716
    } else {
717
      II = getIdentifierInfo(CleanedStr);
718
    }
719
  }
720

721
  // Update the token info (identifier info and appropriate token kind).
722
  // FIXME: the raw_identifier may contain leading whitespace which is removed
723
  // from the cleaned identifier token. The SourceLocation should be updated to
724
  // refer to the non-whitespace character. For instance, the text "\\\nB" (a
725
  // line continuation before 'B') is parsed as a single tok::raw_identifier and
726
  // is cleaned to tok::identifier "B". After cleaning the token's length is
727
  // still 3 and the SourceLocation refers to the location of the backslash.
728
  Identifier.setIdentifierInfo(II);
729
  Identifier.setKind(II->getTokenID());
730

731
  return II;
732
}
733

734
void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
735
  PoisonReasons[II] = DiagID;
736
}
737

738
void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
739
  assert(Ident__exception_code && Ident__exception_info);
740
  assert(Ident___exception_code && Ident___exception_info);
741
  Ident__exception_code->setIsPoisoned(Poison);
742
  Ident___exception_code->setIsPoisoned(Poison);
743
  Ident_GetExceptionCode->setIsPoisoned(Poison);
744
  Ident__exception_info->setIsPoisoned(Poison);
745
  Ident___exception_info->setIsPoisoned(Poison);
746
  Ident_GetExceptionInfo->setIsPoisoned(Poison);
747
  Ident__abnormal_termination->setIsPoisoned(Poison);
748
  Ident___abnormal_termination->setIsPoisoned(Poison);
749
  Ident_AbnormalTermination->setIsPoisoned(Poison);
750
}
751

752
void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
753
  assert(Identifier.getIdentifierInfo() &&
754
         "Can't handle identifiers without identifier info!");
755
  llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
756
    PoisonReasons.find(Identifier.getIdentifierInfo());
757
  if(it == PoisonReasons.end())
758
    Diag(Identifier, diag::err_pp_used_poisoned_id);
759
  else
760
    Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
761
}
762

763
void Preprocessor::updateOutOfDateIdentifier(const IdentifierInfo &II) const {
764
  assert(II.isOutOfDate() && "not out of date");
765
  getExternalSource()->updateOutOfDateIdentifier(II);
766
}
767

768
/// HandleIdentifier - This callback is invoked when the lexer reads an
769
/// identifier.  This callback looks up the identifier in the map and/or
770
/// potentially macro expands it or turns it into a named token (like 'for').
771
///
772
/// Note that callers of this method are guarded by checking the
773
/// IdentifierInfo's 'isHandleIdentifierCase' bit.  If this method changes, the
774
/// IdentifierInfo methods that compute these properties will need to change to
775
/// match.
776
bool Preprocessor::HandleIdentifier(Token &Identifier) {
777
  assert(Identifier.getIdentifierInfo() &&
778
         "Can't handle identifiers without identifier info!");
779

780
  IdentifierInfo &II = *Identifier.getIdentifierInfo();
781

782
  // If the information about this identifier is out of date, update it from
783
  // the external source.
784
  // We have to treat __VA_ARGS__ in a special way, since it gets
785
  // serialized with isPoisoned = true, but our preprocessor may have
786
  // unpoisoned it if we're defining a C99 macro.
787
  if (II.isOutOfDate()) {
788
    bool CurrentIsPoisoned = false;
789
    const bool IsSpecialVariadicMacro =
790
        &II == Ident__VA_ARGS__ || &II == Ident__VA_OPT__;
791
    if (IsSpecialVariadicMacro)
792
      CurrentIsPoisoned = II.isPoisoned();
793

794
    updateOutOfDateIdentifier(II);
795
    Identifier.setKind(II.getTokenID());
796

797
    if (IsSpecialVariadicMacro)
798
      II.setIsPoisoned(CurrentIsPoisoned);
799
  }
800

801
  // If this identifier was poisoned, and if it was not produced from a macro
802
  // expansion, emit an error.
803
  if (II.isPoisoned() && CurPPLexer) {
804
    HandlePoisonedIdentifier(Identifier);
805
  }
806

807
  // If this is a macro to be expanded, do it.
808
  if (const MacroDefinition MD = getMacroDefinition(&II)) {
809
    const auto *MI = MD.getMacroInfo();
810
    assert(MI && "macro definition with no macro info?");
811
    if (!DisableMacroExpansion) {
812
      if (!Identifier.isExpandDisabled() && MI->isEnabled()) {
813
        // C99 6.10.3p10: If the preprocessing token immediately after the
814
        // macro name isn't a '(', this macro should not be expanded.
815
        if (!MI->isFunctionLike() || isNextPPTokenLParen())
816
          return HandleMacroExpandedIdentifier(Identifier, MD);
817
      } else {
818
        // C99 6.10.3.4p2 says that a disabled macro may never again be
819
        // expanded, even if it's in a context where it could be expanded in the
820
        // future.
821
        Identifier.setFlag(Token::DisableExpand);
822
        if (MI->isObjectLike() || isNextPPTokenLParen())
823
          Diag(Identifier, diag::pp_disabled_macro_expansion);
824
      }
825
    }
826
  }
827

828
  // If this identifier is a keyword in a newer Standard or proposed Standard,
829
  // produce a warning. Don't warn if we're not considering macro expansion,
830
  // since this identifier might be the name of a macro.
831
  // FIXME: This warning is disabled in cases where it shouldn't be, like
832
  //   "#define constexpr constexpr", "int constexpr;"
833
  if (II.isFutureCompatKeyword() && !DisableMacroExpansion) {
834
    Diag(Identifier, getIdentifierTable().getFutureCompatDiagKind(II, getLangOpts()))
835
        << II.getName();
836
    // Don't diagnose this keyword again in this translation unit.
837
    II.setIsFutureCompatKeyword(false);
838
  }
839

840
  // If this is an extension token, diagnose its use.
841
  // We avoid diagnosing tokens that originate from macro definitions.
842
  // FIXME: This warning is disabled in cases where it shouldn't be,
843
  // like "#define TY typeof", "TY(1) x".
844
  if (II.isExtensionToken() && !DisableMacroExpansion)
845
    Diag(Identifier, diag::ext_token_used);
846

847
  // If this is the 'import' contextual keyword following an '@', note
848
  // that the next token indicates a module name.
849
  //
850
  // Note that we do not treat 'import' as a contextual
851
  // keyword when we're in a caching lexer, because caching lexers only get
852
  // used in contexts where import declarations are disallowed.
853
  //
854
  // Likewise if this is the standard C++ import keyword.
855
  if (((LastTokenWasAt && II.isModulesImport()) ||
856
       Identifier.is(tok::kw_import)) &&
857
      !InMacroArgs && !DisableMacroExpansion &&
858
      (getLangOpts().Modules || getLangOpts().DebuggerSupport) &&
859
      CurLexerCallback != CLK_CachingLexer) {
860
    ModuleImportLoc = Identifier.getLocation();
861
    NamedModuleImportPath.clear();
862
    IsAtImport = true;
863
    ModuleImportExpectsIdentifier = true;
864
    CurLexerCallback = CLK_LexAfterModuleImport;
865
  }
866
  return true;
867
}
868

869
void Preprocessor::Lex(Token &Result) {
870
  ++LexLevel;
871

872
  // We loop here until a lex function returns a token; this avoids recursion.
873
  while (!CurLexerCallback(*this, Result))
874
    ;
875

876
  if (Result.is(tok::unknown) && TheModuleLoader.HadFatalFailure)
877
    return;
878

879
  if (Result.is(tok::code_completion) && Result.getIdentifierInfo()) {
880
    // Remember the identifier before code completion token.
881
    setCodeCompletionIdentifierInfo(Result.getIdentifierInfo());
882
    setCodeCompletionTokenRange(Result.getLocation(), Result.getEndLoc());
883
    // Set IdenfitierInfo to null to avoid confusing code that handles both
884
    // identifiers and completion tokens.
885
    Result.setIdentifierInfo(nullptr);
886
  }
887

888
  // Update StdCXXImportSeqState to track our position within a C++20 import-seq
889
  // if this token is being produced as a result of phase 4 of translation.
890
  // Update TrackGMFState to decide if we are currently in a Global Module
891
  // Fragment. GMF state updates should precede StdCXXImportSeq ones, since GMF state
892
  // depends on the prevailing StdCXXImportSeq state in two cases.
893
  if (getLangOpts().CPlusPlusModules && LexLevel == 1 &&
894
      !Result.getFlag(Token::IsReinjected)) {
895
    switch (Result.getKind()) {
896
    case tok::l_paren: case tok::l_square: case tok::l_brace:
897
      StdCXXImportSeqState.handleOpenBracket();
898
      break;
899
    case tok::r_paren: case tok::r_square:
900
      StdCXXImportSeqState.handleCloseBracket();
901
      break;
902
    case tok::r_brace:
903
      StdCXXImportSeqState.handleCloseBrace();
904
      break;
905
    // This token is injected to represent the translation of '#include "a.h"'
906
    // into "import a.h;". Mimic the notional ';'.
907
    case tok::annot_module_include:
908
    case tok::semi:
909
      TrackGMFState.handleSemi();
910
      StdCXXImportSeqState.handleSemi();
911
      ModuleDeclState.handleSemi();
912
      break;
913
    case tok::header_name:
914
    case tok::annot_header_unit:
915
      StdCXXImportSeqState.handleHeaderName();
916
      break;
917
    case tok::kw_export:
918
      TrackGMFState.handleExport();
919
      StdCXXImportSeqState.handleExport();
920
      ModuleDeclState.handleExport();
921
      break;
922
    case tok::colon:
923
      ModuleDeclState.handleColon();
924
      break;
925
    case tok::period:
926
      ModuleDeclState.handlePeriod();
927
      break;
928
    case tok::identifier:
929
      // Check "import" and "module" when there is no open bracket. The two
930
      // identifiers are not meaningful with open brackets.
931
      if (StdCXXImportSeqState.atTopLevel()) {
932
        if (Result.getIdentifierInfo()->isModulesImport()) {
933
          TrackGMFState.handleImport(StdCXXImportSeqState.afterTopLevelSeq());
934
          StdCXXImportSeqState.handleImport();
935
          if (StdCXXImportSeqState.afterImportSeq()) {
936
            ModuleImportLoc = Result.getLocation();
937
            NamedModuleImportPath.clear();
938
            IsAtImport = false;
939
            ModuleImportExpectsIdentifier = true;
940
            CurLexerCallback = CLK_LexAfterModuleImport;
941
          }
942
          break;
943
        } else if (Result.getIdentifierInfo() == getIdentifierInfo("module")) {
944
          TrackGMFState.handleModule(StdCXXImportSeqState.afterTopLevelSeq());
945
          ModuleDeclState.handleModule();
946
          break;
947
        }
948
      }
949
      ModuleDeclState.handleIdentifier(Result.getIdentifierInfo());
950
      if (ModuleDeclState.isModuleCandidate())
951
        break;
952
      [[fallthrough]];
953
    default:
954
      TrackGMFState.handleMisc();
955
      StdCXXImportSeqState.handleMisc();
956
      ModuleDeclState.handleMisc();
957
      break;
958
    }
959
  }
960

961
  if (CurLexer && ++CheckPointCounter == CheckPointStepSize) {
962
    CheckPoints[CurLexer->getFileID()].push_back(CurLexer->BufferPtr);
963
    CheckPointCounter = 0;
964
  }
965

966
  LastTokenWasAt = Result.is(tok::at);
967
  --LexLevel;
968

969
  if ((LexLevel == 0 || PreprocessToken) &&
970
      !Result.getFlag(Token::IsReinjected)) {
971
    if (LexLevel == 0)
972
      ++TokenCount;
973
    if (OnToken)
974
      OnToken(Result);
975
  }
976
}
977

978
void Preprocessor::LexTokensUntilEOF(std::vector<Token> *Tokens) {
979
  while (1) {
980
    Token Tok;
981
    Lex(Tok);
982
    if (Tok.isOneOf(tok::unknown, tok::eof, tok::eod,
983
                    tok::annot_repl_input_end))
984
      break;
985
    if (Tokens != nullptr)
986
      Tokens->push_back(Tok);
987
  }
988
}
989

990
/// Lex a header-name token (including one formed from header-name-tokens if
991
/// \p AllowConcatenation is \c true).
992
///
993
/// \param FilenameTok Filled in with the next token. On success, this will
994
///        be either a header_name token. On failure, it will be whatever other
995
///        token was found instead.
996
/// \param AllowMacroExpansion If \c true, allow the header name to be formed
997
///        by macro expansion (concatenating tokens as necessary if the first
998
///        token is a '<').
999
/// \return \c true if we reached EOD or EOF while looking for a > token in
1000
///         a concatenated header name and diagnosed it. \c false otherwise.
1001
bool Preprocessor::LexHeaderName(Token &FilenameTok, bool AllowMacroExpansion) {
1002
  // Lex using header-name tokenization rules if tokens are being lexed from
1003
  // a file. Just grab a token normally if we're in a macro expansion.
1004
  if (CurPPLexer)
1005
    CurPPLexer->LexIncludeFilename(FilenameTok);
1006
  else
1007
    Lex(FilenameTok);
1008

1009
  // This could be a <foo/bar.h> file coming from a macro expansion.  In this
1010
  // case, glue the tokens together into an angle_string_literal token.
1011
  SmallString<128> FilenameBuffer;
1012
  if (FilenameTok.is(tok::less) && AllowMacroExpansion) {
1013
    bool StartOfLine = FilenameTok.isAtStartOfLine();
1014
    bool LeadingSpace = FilenameTok.hasLeadingSpace();
1015
    bool LeadingEmptyMacro = FilenameTok.hasLeadingEmptyMacro();
1016

1017
    SourceLocation Start = FilenameTok.getLocation();
1018
    SourceLocation End;
1019
    FilenameBuffer.push_back('<');
1020

1021
    // Consume tokens until we find a '>'.
1022
    // FIXME: A header-name could be formed starting or ending with an
1023
    // alternative token. It's not clear whether that's ill-formed in all
1024
    // cases.
1025
    while (FilenameTok.isNot(tok::greater)) {
1026
      Lex(FilenameTok);
1027
      if (FilenameTok.isOneOf(tok::eod, tok::eof)) {
1028
        Diag(FilenameTok.getLocation(), diag::err_expected) << tok::greater;
1029
        Diag(Start, diag::note_matching) << tok::less;
1030
        return true;
1031
      }
1032

1033
      End = FilenameTok.getLocation();
1034

1035
      // FIXME: Provide code completion for #includes.
1036
      if (FilenameTok.is(tok::code_completion)) {
1037
        setCodeCompletionReached();
1038
        Lex(FilenameTok);
1039
        continue;
1040
      }
1041

1042
      // Append the spelling of this token to the buffer. If there was a space
1043
      // before it, add it now.
1044
      if (FilenameTok.hasLeadingSpace())
1045
        FilenameBuffer.push_back(' ');
1046

1047
      // Get the spelling of the token, directly into FilenameBuffer if
1048
      // possible.
1049
      size_t PreAppendSize = FilenameBuffer.size();
1050
      FilenameBuffer.resize(PreAppendSize + FilenameTok.getLength());
1051

1052
      const char *BufPtr = &FilenameBuffer[PreAppendSize];
1053
      unsigned ActualLen = getSpelling(FilenameTok, BufPtr);
1054

1055
      // If the token was spelled somewhere else, copy it into FilenameBuffer.
1056
      if (BufPtr != &FilenameBuffer[PreAppendSize])
1057
        memcpy(&FilenameBuffer[PreAppendSize], BufPtr, ActualLen);
1058

1059
      // Resize FilenameBuffer to the correct size.
1060
      if (FilenameTok.getLength() != ActualLen)
1061
        FilenameBuffer.resize(PreAppendSize + ActualLen);
1062
    }
1063

1064
    FilenameTok.startToken();
1065
    FilenameTok.setKind(tok::header_name);
1066
    FilenameTok.setFlagValue(Token::StartOfLine, StartOfLine);
1067
    FilenameTok.setFlagValue(Token::LeadingSpace, LeadingSpace);
1068
    FilenameTok.setFlagValue(Token::LeadingEmptyMacro, LeadingEmptyMacro);
1069
    CreateString(FilenameBuffer, FilenameTok, Start, End);
1070
  } else if (FilenameTok.is(tok::string_literal) && AllowMacroExpansion) {
1071
    // Convert a string-literal token of the form " h-char-sequence "
1072
    // (produced by macro expansion) into a header-name token.
1073
    //
1074
    // The rules for header-names don't quite match the rules for
1075
    // string-literals, but all the places where they differ result in
1076
    // undefined behavior, so we can and do treat them the same.
1077
    //
1078
    // A string-literal with a prefix or suffix is not translated into a
1079
    // header-name. This could theoretically be observable via the C++20
1080
    // context-sensitive header-name formation rules.
1081
    StringRef Str = getSpelling(FilenameTok, FilenameBuffer);
1082
    if (Str.size() >= 2 && Str.front() == '"' && Str.back() == '"')
1083
      FilenameTok.setKind(tok::header_name);
1084
  }
1085

1086
  return false;
1087
}
1088

1089
/// Collect the tokens of a C++20 pp-import-suffix.
1090
void Preprocessor::CollectPpImportSuffix(SmallVectorImpl<Token> &Toks) {
1091
  // FIXME: For error recovery, consider recognizing attribute syntax here
1092
  // and terminating / diagnosing a missing semicolon if we find anything
1093
  // else? (Can we leave that to the parser?)
1094
  unsigned BracketDepth = 0;
1095
  while (true) {
1096
    Toks.emplace_back();
1097
    Lex(Toks.back());
1098

1099
    switch (Toks.back().getKind()) {
1100
    case tok::l_paren: case tok::l_square: case tok::l_brace:
1101
      ++BracketDepth;
1102
      break;
1103

1104
    case tok::r_paren: case tok::r_square: case tok::r_brace:
1105
      if (BracketDepth == 0)
1106
        return;
1107
      --BracketDepth;
1108
      break;
1109

1110
    case tok::semi:
1111
      if (BracketDepth == 0)
1112
        return;
1113
    break;
1114

1115
    case tok::eof:
1116
      return;
1117

1118
    default:
1119
      break;
1120
    }
1121
  }
1122
}
1123

1124

1125
/// Lex a token following the 'import' contextual keyword.
1126
///
1127
///     pp-import: [C++20]
1128
///           import header-name pp-import-suffix[opt] ;
1129
///           import header-name-tokens pp-import-suffix[opt] ;
1130
/// [ObjC]    @ import module-name ;
1131
/// [Clang]   import module-name ;
1132
///
1133
///     header-name-tokens:
1134
///           string-literal
1135
///           < [any sequence of preprocessing-tokens other than >] >
1136
///
1137
///     module-name:
1138
///           module-name-qualifier[opt] identifier
1139
///
1140
///     module-name-qualifier
1141
///           module-name-qualifier[opt] identifier .
1142
///
1143
/// We respond to a pp-import by importing macros from the named module.
1144
bool Preprocessor::LexAfterModuleImport(Token &Result) {
1145
  // Figure out what kind of lexer we actually have.
1146
  recomputeCurLexerKind();
1147

1148
  // Lex the next token. The header-name lexing rules are used at the start of
1149
  // a pp-import.
1150
  //
1151
  // For now, we only support header-name imports in C++20 mode.
1152
  // FIXME: Should we allow this in all language modes that support an import
1153
  // declaration as an extension?
1154
  if (NamedModuleImportPath.empty() && getLangOpts().CPlusPlusModules) {
1155
    if (LexHeaderName(Result))
1156
      return true;
1157

1158
    if (Result.is(tok::colon) && ModuleDeclState.isNamedModule()) {
1159
      std::string Name = ModuleDeclState.getPrimaryName().str();
1160
      Name += ":";
1161
      NamedModuleImportPath.push_back(
1162
          {getIdentifierInfo(Name), Result.getLocation()});
1163
      CurLexerCallback = CLK_LexAfterModuleImport;
1164
      return true;
1165
    }
1166
  } else {
1167
    Lex(Result);
1168
  }
1169

1170
  // Allocate a holding buffer for a sequence of tokens and introduce it into
1171
  // the token stream.
1172
  auto EnterTokens = [this](ArrayRef<Token> Toks) {
1173
    auto ToksCopy = std::make_unique<Token[]>(Toks.size());
1174
    std::copy(Toks.begin(), Toks.end(), ToksCopy.get());
1175
    EnterTokenStream(std::move(ToksCopy), Toks.size(),
1176
                     /*DisableMacroExpansion*/ true, /*IsReinject*/ false);
1177
  };
1178

1179
  bool ImportingHeader = Result.is(tok::header_name);
1180
  // Check for a header-name.
1181
  SmallVector<Token, 32> Suffix;
1182
  if (ImportingHeader) {
1183
    // Enter the header-name token into the token stream; a Lex action cannot
1184
    // both return a token and cache tokens (doing so would corrupt the token
1185
    // cache if the call to Lex comes from CachingLex / PeekAhead).
1186
    Suffix.push_back(Result);
1187

1188
    // Consume the pp-import-suffix and expand any macros in it now. We'll add
1189
    // it back into the token stream later.
1190
    CollectPpImportSuffix(Suffix);
1191
    if (Suffix.back().isNot(tok::semi)) {
1192
      // This is not a pp-import after all.
1193
      EnterTokens(Suffix);
1194
      return false;
1195
    }
1196

1197
    // C++2a [cpp.module]p1:
1198
    //   The ';' preprocessing-token terminating a pp-import shall not have
1199
    //   been produced by macro replacement.
1200
    SourceLocation SemiLoc = Suffix.back().getLocation();
1201
    if (SemiLoc.isMacroID())
1202
      Diag(SemiLoc, diag::err_header_import_semi_in_macro);
1203

1204
    // Reconstitute the import token.
1205
    Token ImportTok;
1206
    ImportTok.startToken();
1207
    ImportTok.setKind(tok::kw_import);
1208
    ImportTok.setLocation(ModuleImportLoc);
1209
    ImportTok.setIdentifierInfo(getIdentifierInfo("import"));
1210
    ImportTok.setLength(6);
1211

1212
    auto Action = HandleHeaderIncludeOrImport(
1213
        /*HashLoc*/ SourceLocation(), ImportTok, Suffix.front(), SemiLoc);
1214
    switch (Action.Kind) {
1215
    case ImportAction::None:
1216
      break;
1217

1218
    case ImportAction::ModuleBegin:
1219
      // Let the parser know we're textually entering the module.
1220
      Suffix.emplace_back();
1221
      Suffix.back().startToken();
1222
      Suffix.back().setKind(tok::annot_module_begin);
1223
      Suffix.back().setLocation(SemiLoc);
1224
      Suffix.back().setAnnotationEndLoc(SemiLoc);
1225
      Suffix.back().setAnnotationValue(Action.ModuleForHeader);
1226
      [[fallthrough]];
1227

1228
    case ImportAction::ModuleImport:
1229
    case ImportAction::HeaderUnitImport:
1230
    case ImportAction::SkippedModuleImport:
1231
      // We chose to import (or textually enter) the file. Convert the
1232
      // header-name token into a header unit annotation token.
1233
      Suffix[0].setKind(tok::annot_header_unit);
1234
      Suffix[0].setAnnotationEndLoc(Suffix[0].getLocation());
1235
      Suffix[0].setAnnotationValue(Action.ModuleForHeader);
1236
      // FIXME: Call the moduleImport callback?
1237
      break;
1238
    case ImportAction::Failure:
1239
      assert(TheModuleLoader.HadFatalFailure &&
1240
             "This should be an early exit only to a fatal error");
1241
      Result.setKind(tok::eof);
1242
      CurLexer->cutOffLexing();
1243
      EnterTokens(Suffix);
1244
      return true;
1245
    }
1246

1247
    EnterTokens(Suffix);
1248
    return false;
1249
  }
1250

1251
  // The token sequence
1252
  //
1253
  //   import identifier (. identifier)*
1254
  //
1255
  // indicates a module import directive. We already saw the 'import'
1256
  // contextual keyword, so now we're looking for the identifiers.
1257
  if (ModuleImportExpectsIdentifier && Result.getKind() == tok::identifier) {
1258
    // We expected to see an identifier here, and we did; continue handling
1259
    // identifiers.
1260
    NamedModuleImportPath.push_back(
1261
        std::make_pair(Result.getIdentifierInfo(), Result.getLocation()));
1262
    ModuleImportExpectsIdentifier = false;
1263
    CurLexerCallback = CLK_LexAfterModuleImport;
1264
    return true;
1265
  }
1266

1267
  // If we're expecting a '.' or a ';', and we got a '.', then wait until we
1268
  // see the next identifier. (We can also see a '[[' that begins an
1269
  // attribute-specifier-seq here under the Standard C++ Modules.)
1270
  if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
1271
    ModuleImportExpectsIdentifier = true;
1272
    CurLexerCallback = CLK_LexAfterModuleImport;
1273
    return true;
1274
  }
1275

1276
  // If we didn't recognize a module name at all, this is not a (valid) import.
1277
  if (NamedModuleImportPath.empty() || Result.is(tok::eof))
1278
    return true;
1279

1280
  // Consume the pp-import-suffix and expand any macros in it now, if we're not
1281
  // at the semicolon already.
1282
  SourceLocation SemiLoc = Result.getLocation();
1283
  if (Result.isNot(tok::semi)) {
1284
    Suffix.push_back(Result);
1285
    CollectPpImportSuffix(Suffix);
1286
    if (Suffix.back().isNot(tok::semi)) {
1287
      // This is not an import after all.
1288
      EnterTokens(Suffix);
1289
      return false;
1290
    }
1291
    SemiLoc = Suffix.back().getLocation();
1292
  }
1293

1294
  // Under the standard C++ Modules, the dot is just part of the module name,
1295
  // and not a real hierarchy separator. Flatten such module names now.
1296
  //
1297
  // FIXME: Is this the right level to be performing this transformation?
1298
  std::string FlatModuleName;
1299
  if (getLangOpts().CPlusPlusModules) {
1300
    for (auto &Piece : NamedModuleImportPath) {
1301
      // If the FlatModuleName ends with colon, it implies it is a partition.
1302
      if (!FlatModuleName.empty() && FlatModuleName.back() != ':')
1303
        FlatModuleName += ".";
1304
      FlatModuleName += Piece.first->getName();
1305
    }
1306
    SourceLocation FirstPathLoc = NamedModuleImportPath[0].second;
1307
    NamedModuleImportPath.clear();
1308
    NamedModuleImportPath.push_back(
1309
        std::make_pair(getIdentifierInfo(FlatModuleName), FirstPathLoc));
1310
  }
1311

1312
  Module *Imported = nullptr;
1313
  // We don't/shouldn't load the standard c++20 modules when preprocessing.
1314
  if (getLangOpts().Modules && !isInImportingCXXNamedModules()) {
1315
    Imported = TheModuleLoader.loadModule(ModuleImportLoc,
1316
                                          NamedModuleImportPath,
1317
                                          Module::Hidden,
1318
                                          /*IsInclusionDirective=*/false);
1319
    if (Imported)
1320
      makeModuleVisible(Imported, SemiLoc);
1321
  }
1322

1323
  if (Callbacks)
1324
    Callbacks->moduleImport(ModuleImportLoc, NamedModuleImportPath, Imported);
1325

1326
  if (!Suffix.empty()) {
1327
    EnterTokens(Suffix);
1328
    return false;
1329
  }
1330
  return true;
1331
}
1332

1333
void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc) {
1334
  CurSubmoduleState->VisibleModules.setVisible(
1335
      M, Loc, [](Module *) {},
1336
      [&](ArrayRef<Module *> Path, Module *Conflict, StringRef Message) {
1337
        // FIXME: Include the path in the diagnostic.
1338
        // FIXME: Include the import location for the conflicting module.
1339
        Diag(ModuleImportLoc, diag::warn_module_conflict)
1340
            << Path[0]->getFullModuleName()
1341
            << Conflict->getFullModuleName()
1342
            << Message;
1343
      });
1344

1345
  // Add this module to the imports list of the currently-built submodule.
1346
  if (!BuildingSubmoduleStack.empty() && M != BuildingSubmoduleStack.back().M)
1347
    BuildingSubmoduleStack.back().M->Imports.insert(M);
1348
}
1349

1350
bool Preprocessor::FinishLexStringLiteral(Token &Result, std::string &String,
1351
                                          const char *DiagnosticTag,
1352
                                          bool AllowMacroExpansion) {
1353
  // We need at least one string literal.
1354
  if (Result.isNot(tok::string_literal)) {
1355
    Diag(Result, diag::err_expected_string_literal)
1356
      << /*Source='in...'*/0 << DiagnosticTag;
1357
    return false;
1358
  }
1359

1360
  // Lex string literal tokens, optionally with macro expansion.
1361
  SmallVector<Token, 4> StrToks;
1362
  do {
1363
    StrToks.push_back(Result);
1364

1365
    if (Result.hasUDSuffix())
1366
      Diag(Result, diag::err_invalid_string_udl);
1367

1368
    if (AllowMacroExpansion)
1369
      Lex(Result);
1370
    else
1371
      LexUnexpandedToken(Result);
1372
  } while (Result.is(tok::string_literal));
1373

1374
  // Concatenate and parse the strings.
1375
  StringLiteralParser Literal(StrToks, *this);
1376
  assert(Literal.isOrdinary() && "Didn't allow wide strings in");
1377

1378
  if (Literal.hadError)
1379
    return false;
1380

1381
  if (Literal.Pascal) {
1382
    Diag(StrToks[0].getLocation(), diag::err_expected_string_literal)
1383
      << /*Source='in...'*/0 << DiagnosticTag;
1384
    return false;
1385
  }
1386

1387
  String = std::string(Literal.GetString());
1388
  return true;
1389
}
1390

1391
bool Preprocessor::parseSimpleIntegerLiteral(Token &Tok, uint64_t &Value) {
1392
  assert(Tok.is(tok::numeric_constant));
1393
  SmallString<8> IntegerBuffer;
1394
  bool NumberInvalid = false;
1395
  StringRef Spelling = getSpelling(Tok, IntegerBuffer, &NumberInvalid);
1396
  if (NumberInvalid)
1397
    return false;
1398
  NumericLiteralParser Literal(Spelling, Tok.getLocation(), getSourceManager(),
1399
                               getLangOpts(), getTargetInfo(),
1400
                               getDiagnostics());
1401
  if (Literal.hadError || !Literal.isIntegerLiteral() || Literal.hasUDSuffix())
1402
    return false;
1403
  llvm::APInt APVal(64, 0);
1404
  if (Literal.GetIntegerValue(APVal))
1405
    return false;
1406
  Lex(Tok);
1407
  Value = APVal.getLimitedValue();
1408
  return true;
1409
}
1410

1411
void Preprocessor::addCommentHandler(CommentHandler *Handler) {
1412
  assert(Handler && "NULL comment handler");
1413
  assert(!llvm::is_contained(CommentHandlers, Handler) &&
1414
         "Comment handler already registered");
1415
  CommentHandlers.push_back(Handler);
1416
}
1417

1418
void Preprocessor::removeCommentHandler(CommentHandler *Handler) {
1419
  std::vector<CommentHandler *>::iterator Pos =
1420
      llvm::find(CommentHandlers, Handler);
1421
  assert(Pos != CommentHandlers.end() && "Comment handler not registered");
1422
  CommentHandlers.erase(Pos);
1423
}
1424

1425
bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
1426
  bool AnyPendingTokens = false;
1427
  for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
1428
       HEnd = CommentHandlers.end();
1429
       H != HEnd; ++H) {
1430
    if ((*H)->HandleComment(*this, Comment))
1431
      AnyPendingTokens = true;
1432
  }
1433
  if (!AnyPendingTokens || getCommentRetentionState())
1434
    return false;
1435
  Lex(result);
1436
  return true;
1437
}
1438

1439
void Preprocessor::emitMacroDeprecationWarning(const Token &Identifier) const {
1440
  const MacroAnnotations &A =
1441
      getMacroAnnotations(Identifier.getIdentifierInfo());
1442
  assert(A.DeprecationInfo &&
1443
         "Macro deprecation warning without recorded annotation!");
1444
  const MacroAnnotationInfo &Info = *A.DeprecationInfo;
1445
  if (Info.Message.empty())
1446
    Diag(Identifier, diag::warn_pragma_deprecated_macro_use)
1447
        << Identifier.getIdentifierInfo() << 0;
1448
  else
1449
    Diag(Identifier, diag::warn_pragma_deprecated_macro_use)
1450
        << Identifier.getIdentifierInfo() << 1 << Info.Message;
1451
  Diag(Info.Location, diag::note_pp_macro_annotation) << 0;
1452
}
1453

1454
void Preprocessor::emitRestrictExpansionWarning(const Token &Identifier) const {
1455
  const MacroAnnotations &A =
1456
      getMacroAnnotations(Identifier.getIdentifierInfo());
1457
  assert(A.RestrictExpansionInfo &&
1458
         "Macro restricted expansion warning without recorded annotation!");
1459
  const MacroAnnotationInfo &Info = *A.RestrictExpansionInfo;
1460
  if (Info.Message.empty())
1461
    Diag(Identifier, diag::warn_pragma_restrict_expansion_macro_use)
1462
        << Identifier.getIdentifierInfo() << 0;
1463
  else
1464
    Diag(Identifier, diag::warn_pragma_restrict_expansion_macro_use)
1465
        << Identifier.getIdentifierInfo() << 1 << Info.Message;
1466
  Diag(Info.Location, diag::note_pp_macro_annotation) << 1;
1467
}
1468

1469
void Preprocessor::emitRestrictInfNaNWarning(const Token &Identifier,
1470
                                             unsigned DiagSelection) const {
1471
  Diag(Identifier, diag::warn_fp_nan_inf_when_disabled) << DiagSelection << 1;
1472
}
1473

1474
void Preprocessor::emitFinalMacroWarning(const Token &Identifier,
1475
                                         bool IsUndef) const {
1476
  const MacroAnnotations &A =
1477
      getMacroAnnotations(Identifier.getIdentifierInfo());
1478
  assert(A.FinalAnnotationLoc &&
1479
         "Final macro warning without recorded annotation!");
1480

1481
  Diag(Identifier, diag::warn_pragma_final_macro)
1482
      << Identifier.getIdentifierInfo() << (IsUndef ? 0 : 1);
1483
  Diag(*A.FinalAnnotationLoc, diag::note_pp_macro_annotation) << 2;
1484
}
1485

1486
bool Preprocessor::isSafeBufferOptOut(const SourceManager &SourceMgr,
1487
                                      const SourceLocation &Loc) const {
1488
  // The lambda that tests if a `Loc` is in an opt-out region given one opt-out
1489
  // region map:
1490
  auto TestInMap = [&SourceMgr](const SafeBufferOptOutRegionsTy &Map,
1491
                                const SourceLocation &Loc) -> bool {
1492
    // Try to find a region in `SafeBufferOptOutMap` where `Loc` is in:
1493
    auto FirstRegionEndingAfterLoc = llvm::partition_point(
1494
        Map, [&SourceMgr,
1495
              &Loc](const std::pair<SourceLocation, SourceLocation> &Region) {
1496
          return SourceMgr.isBeforeInTranslationUnit(Region.second, Loc);
1497
        });
1498

1499
    if (FirstRegionEndingAfterLoc != Map.end()) {
1500
      // To test if the start location of the found region precedes `Loc`:
1501
      return SourceMgr.isBeforeInTranslationUnit(
1502
          FirstRegionEndingAfterLoc->first, Loc);
1503
    }
1504
    // If we do not find a region whose end location passes `Loc`, we want to
1505
    // check if the current region is still open:
1506
    if (!Map.empty() && Map.back().first == Map.back().second)
1507
      return SourceMgr.isBeforeInTranslationUnit(Map.back().first, Loc);
1508
    return false;
1509
  };
1510

1511
  // What the following does:
1512
  //
1513
  // If `Loc` belongs to the local TU, we just look up `SafeBufferOptOutMap`.
1514
  // Otherwise, `Loc` is from a loaded AST.  We look up the
1515
  // `LoadedSafeBufferOptOutMap` first to get the opt-out region map of the
1516
  // loaded AST where `Loc` is at.  Then we find if `Loc` is in an opt-out
1517
  // region w.r.t. the region map.  If the region map is absent, it means there
1518
  // is no opt-out pragma in that loaded AST.
1519
  //
1520
  // Opt-out pragmas in the local TU or a loaded AST is not visible to another
1521
  // one of them.  That means if you put the pragmas around a `#include
1522
  // "module.h"`, where module.h is a module, it is not actually suppressing
1523
  // warnings in module.h.  This is fine because warnings in module.h will be
1524
  // reported when module.h is compiled in isolation and nothing in module.h
1525
  // will be analyzed ever again.  So you will not see warnings from the file
1526
  // that imports module.h anyway. And you can't even do the same thing for PCHs
1527
  //  because they can only be included from the command line.
1528

1529
  if (SourceMgr.isLocalSourceLocation(Loc))
1530
    return TestInMap(SafeBufferOptOutMap, Loc);
1531

1532
  const SafeBufferOptOutRegionsTy *LoadedRegions =
1533
      LoadedSafeBufferOptOutMap.lookupLoadedOptOutMap(Loc, SourceMgr);
1534

1535
  if (LoadedRegions)
1536
    return TestInMap(*LoadedRegions, Loc);
1537
  return false;
1538
}
1539

1540
bool Preprocessor::enterOrExitSafeBufferOptOutRegion(
1541
    bool isEnter, const SourceLocation &Loc) {
1542
  if (isEnter) {
1543
    if (isPPInSafeBufferOptOutRegion())
1544
      return true; // invalid enter action
1545
    InSafeBufferOptOutRegion = true;
1546
    CurrentSafeBufferOptOutStart = Loc;
1547

1548
    // To set the start location of a new region:
1549

1550
    if (!SafeBufferOptOutMap.empty()) {
1551
      [[maybe_unused]] auto *PrevRegion = &SafeBufferOptOutMap.back();
1552
      assert(PrevRegion->first != PrevRegion->second &&
1553
             "Shall not begin a safe buffer opt-out region before closing the "
1554
             "previous one.");
1555
    }
1556
    // If the start location equals to the end location, we call the region a
1557
    // open region or a unclosed region (i.e., end location has not been set
1558
    // yet).
1559
    SafeBufferOptOutMap.emplace_back(Loc, Loc);
1560
  } else {
1561
    if (!isPPInSafeBufferOptOutRegion())
1562
      return true; // invalid enter action
1563
    InSafeBufferOptOutRegion = false;
1564

1565
    // To set the end location of the current open region:
1566

1567
    assert(!SafeBufferOptOutMap.empty() &&
1568
           "Misordered safe buffer opt-out regions");
1569
    auto *CurrRegion = &SafeBufferOptOutMap.back();
1570
    assert(CurrRegion->first == CurrRegion->second &&
1571
           "Set end location to a closed safe buffer opt-out region");
1572
    CurrRegion->second = Loc;
1573
  }
1574
  return false;
1575
}
1576

1577
bool Preprocessor::isPPInSafeBufferOptOutRegion() {
1578
  return InSafeBufferOptOutRegion;
1579
}
1580
bool Preprocessor::isPPInSafeBufferOptOutRegion(SourceLocation &StartLoc) {
1581
  StartLoc = CurrentSafeBufferOptOutStart;
1582
  return InSafeBufferOptOutRegion;
1583
}
1584

1585
SmallVector<SourceLocation, 64>
1586
Preprocessor::serializeSafeBufferOptOutMap() const {
1587
  assert(!InSafeBufferOptOutRegion &&
1588
         "Attempt to serialize safe buffer opt-out regions before file being "
1589
         "completely preprocessed");
1590

1591
  SmallVector<SourceLocation, 64> SrcSeq;
1592

1593
  for (const auto &[begin, end] : SafeBufferOptOutMap) {
1594
    SrcSeq.push_back(begin);
1595
    SrcSeq.push_back(end);
1596
  }
1597
  // Only `SafeBufferOptOutMap` gets serialized. No need to serialize
1598
  // `LoadedSafeBufferOptOutMap` because if this TU loads a pch/module, every
1599
  // pch/module in the pch-chain/module-DAG will be loaded one by one in order.
1600
  // It means that for each loading pch/module m, it just needs to load m's own
1601
  // `SafeBufferOptOutMap`.
1602
  return SrcSeq;
1603
}
1604

1605
bool Preprocessor::setDeserializedSafeBufferOptOutMap(
1606
    const SmallVectorImpl<SourceLocation> &SourceLocations) {
1607
  if (SourceLocations.size() == 0)
1608
    return false;
1609

1610
  assert(SourceLocations.size() % 2 == 0 &&
1611
         "ill-formed SourceLocation sequence");
1612

1613
  auto It = SourceLocations.begin();
1614
  SafeBufferOptOutRegionsTy &Regions =
1615
      LoadedSafeBufferOptOutMap.findAndConsLoadedOptOutMap(*It, SourceMgr);
1616

1617
  do {
1618
    SourceLocation Begin = *It++;
1619
    SourceLocation End = *It++;
1620

1621
    Regions.emplace_back(Begin, End);
1622
  } while (It != SourceLocations.end());
1623
  return true;
1624
}
1625

1626
ModuleLoader::~ModuleLoader() = default;
1627

1628
CommentHandler::~CommentHandler() = default;
1629

1630
EmptylineHandler::~EmptylineHandler() = default;
1631

1632
CodeCompletionHandler::~CodeCompletionHandler() = default;
1633

1634
void Preprocessor::createPreprocessingRecord() {
1635
  if (Record)
1636
    return;
1637

1638
  Record = new PreprocessingRecord(getSourceManager());
1639
  addPPCallbacks(std::unique_ptr<PPCallbacks>(Record));
1640
}
1641

1642
const char *Preprocessor::getCheckPoint(FileID FID, const char *Start) const {
1643
  if (auto It = CheckPoints.find(FID); It != CheckPoints.end()) {
1644
    const SmallVector<const char *> &FileCheckPoints = It->second;
1645
    const char *Last = nullptr;
1646
    // FIXME: Do better than a linear search.
1647
    for (const char *P : FileCheckPoints) {
1648
      if (P > Start)
1649
        break;
1650
      Last = P;
1651
    }
1652
    return Last;
1653
  }
1654

1655
  return nullptr;
1656
}
1657