ParsedAST.cpp

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//===--- ParsedAST.cpp -------------------------------------------*- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "ParsedAST.h"
#include "AST.h"
#include "CollectMacros.h"
#include "Compiler.h"
#include "Config.h"
#include "Diagnostics.h"
#include "FeatureModule.h"
#include "Headers.h"
#include "IncludeCleaner.h"
#include "IncludeFixer.h"
#include "Preamble.h"
#include "SourceCode.h"
#include "clang-include-cleaner/Record.h"
#include "index/Symbol.h"
#include "support/Logger.h"
#include "support/Path.h"
#include "support/Trace.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclGroup.h"
#include "clang/AST/ExternalASTSource.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticIDs.h"
#include "clang/Basic/DiagnosticSema.h"
#include "clang/Basic/FileEntry.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/CompilerInvocation.h"
#include "clang/Frontend/FrontendActions.h"
#include "clang/Frontend/FrontendOptions.h"
#include "clang/Frontend/PrecompiledPreamble.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Lex/PreprocessingRecord.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/HeuristicResolver.h"
#include "clang/Serialization/ASTWriter.h"
#include "clang/Tooling/CompilationDatabase.h"
#include "clang/Tooling/Syntax/Tokens.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/STLFunctionalExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cassert>
#include <cstddef>
#include <iterator>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include <vector>
 
namespace clang {
namespace clangd {
namespace {
 
template <class T> std::size_t getUsedBytes(const std::vector<T> &Vec) {
  return Vec.capacity() * sizeof(T);
}
 
class DeclTrackingASTConsumer : public ASTConsumer {
public:
  DeclTrackingASTConsumer(std::vector<Decl *> &TopLevelDecls)
      : TopLevelDecls(TopLevelDecls) {}
 
  bool HandleTopLevelDecl(DeclGroupRef DG) override {
    for (Decl *D : DG) {
      auto &SM = D->getASTContext().getSourceManager();
      if (!isInsideMainFile(D->getLocation(), SM))
        continue;
      if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
        if (isImplicitTemplateInstantiation(ND))
          continue;
 
      // ObjCMethodDecl are not actually top-level decls.
      if (isa<ObjCMethodDecl>(D))
        continue;
 
      TopLevelDecls.push_back(D);
    }
    return true;
  }
 
private:
  std::vector<Decl *> &TopLevelDecls;
};
 
class ClangdFrontendAction : public SyntaxOnlyAction {
public:
  std::vector<Decl *> takeTopLevelDecls() { return std::move(TopLevelDecls); }
 
protected:
  std::unique_ptr<ASTConsumer>
  CreateASTConsumer(CompilerInstance &CI, llvm::StringRef InFile) override {
    return std::make_unique<DeclTrackingASTConsumer>(/*ref*/ TopLevelDecls);
  }
 
private:
  std::vector<Decl *> TopLevelDecls;
};
 
// When using a preamble, only preprocessor events outside its bounds are seen.
// This is almost what we want: replaying transitive preprocessing wastes time.
// However this confuses clang-tidy checks: they don't see any #includes!
// So we replay the *non-transitive* #includes that appear in the main-file.
// It would be nice to replay other events (macro definitions, ifdefs etc) but
// this addresses the most common cases fairly cheaply.
class ReplayPreamble : private PPCallbacks {
public:
  // Attach preprocessor hooks such that preamble events will be injected at
  // the appropriate time.
  // Events will be delivered to the *currently registered* PP callbacks.
  static void attach(std::vector<Inclusion> Includes,
                     const MainFileMacros Macros, CompilerInstance &Clang,
                     const PreambleBounds &PB) {
    auto &PP = Clang.getPreprocessor();
    auto *ExistingCallbacks = PP.getPPCallbacks();
    // No need to replay events if nobody is listening.
    if (!ExistingCallbacks)
      return;
    PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(new ReplayPreamble(
        std::move(Includes), std::move(Macros), ExistingCallbacks,
        Clang.getSourceManager(), PP, Clang.getLangOpts(), PB)));
    // We're relying on the fact that addPPCallbacks keeps the old PPCallbacks
    // around, creating a chaining wrapper. Guard against other implementations.
    assert(PP.getPPCallbacks() != ExistingCallbacks &&
           "Expected chaining implementation");
  }
 
private:
  ReplayPreamble(std::vector<Inclusion> Includes, MainFileMacros Macros,
                 PPCallbacks *Delegate, const SourceManager &SM,
                 Preprocessor &PP, const LangOptions &LangOpts,
                 const PreambleBounds &PB)
      : Includes(std::move(Includes)), Macros(std::move(Macros)),
        Delegate(Delegate), SM(SM), PP(PP) {
    // Only tokenize the preamble section of the main file, as we are not
    // interested in the rest of the tokens.
    MainFileTokens = syntax::tokenize(
        syntax::FileRange(SM.getMainFileID(), 0, PB.Size), SM, LangOpts);
  }
 
  // In a normal compile, the preamble traverses the following structure:
  //
  // mainfile.cpp
  //   <built-in>
  //     ... macro definitions like __cplusplus ...
  //     <command-line>
  //       ... macro definitions for args like -Dfoo=bar ...
  //   "header1.h"
  //     ... header file contents ...
  //   "header2.h"
  //     ... header file contents ...
  //   ... main file contents ...
  //
  // When using a preamble, the "header1" and "header2" subtrees get skipped.
  // We insert them right after the built-in header, which still appears.
  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
                   SrcMgr::CharacteristicKind Kind, FileID PrevFID) override {
    // It'd be nice if there was a better way to identify built-in headers...
    if (Reason == FileChangeReason::ExitFile &&
        SM.getBufferOrFake(PrevFID).getBufferIdentifier() == "<built-in>")
      replay();
  }
 
  void replay() {
    // Replay macro definitions from the preamble region of the main file,
    // so that clang-tidy checks can observe them.
    for (const auto &[SID, Refs] : Macros.MacroRefs) {
      for (const auto &Ref : Refs) {
        if (!Ref.IsDefinition)
          continue;
        auto Loc = SM.getComposedLoc(SM.getMainFileID(), Ref.StartOffset);
        Token Tok;
        if (Lexer::getRawToken(Loc, Tok, SM, PP.getLangOpts(), false))
          continue;
        if (auto *II = PP.getIdentifierInfo(Tok.getRawIdentifier())) {
          Tok.setIdentifierInfo(II);
          Tok.setKind(tok::identifier);
          if (auto *MD = PP.getLocalMacroDirective(II))
            Delegate->MacroDefined(Tok, MD);
        }
      }
    }
    for (const auto &Inc : Includes) {
      OptionalFileEntryRef File;
      if (Inc.Resolved != "")
        File = expectedToOptional(SM.getFileManager().getFileRef(Inc.Resolved));
 
      // Re-lex the #include directive to find its interesting parts.
      auto HashLoc = SM.getComposedLoc(SM.getMainFileID(), Inc.HashOffset);
      auto HashTok = llvm::partition_point(MainFileTokens,
                                           [&HashLoc](const syntax::Token &T) {
                                             return T.location() < HashLoc;
                                           });
      assert(HashTok != MainFileTokens.end() && HashTok->kind() == tok::hash);
 
      auto IncludeTok = std::next(HashTok);
      assert(IncludeTok != MainFileTokens.end());
 
      auto FileTok = std::next(IncludeTok);
      assert(FileTok != MainFileTokens.end());
 
      // Create a fake import/include token, none of the callers seem to care
      // about clang::Token::Flags.
      Token SynthesizedIncludeTok;
      SynthesizedIncludeTok.startToken();
      SynthesizedIncludeTok.setLocation(IncludeTok->location());
      SynthesizedIncludeTok.setLength(IncludeTok->length());
      SynthesizedIncludeTok.setKind(tok::raw_identifier);
      SynthesizedIncludeTok.setRawIdentifierData(IncludeTok->text(SM).data());
      PP.LookUpIdentifierInfo(SynthesizedIncludeTok);
 
      // Same here, create a fake one for Filename, including angles or quotes.
      Token SynthesizedFilenameTok;
      SynthesizedFilenameTok.startToken();
      SynthesizedFilenameTok.setLocation(FileTok->location());
      // Note that we can't make use of FileTok->length/text in here as in the
      // case of angled includes this will contain tok::less instead of
      // filename. Whereas Inc.Written contains the full header name including
      // quotes/angles.
      SynthesizedFilenameTok.setLength(Inc.Written.length());
      SynthesizedFilenameTok.setKind(tok::header_name);
      SynthesizedFilenameTok.setLiteralData(Inc.Written.data());
 
      llvm::StringRef WrittenFilename =
          llvm::StringRef(Inc.Written).drop_front().drop_back();
      Delegate->InclusionDirective(
          HashTok->location(), SynthesizedIncludeTok, WrittenFilename,
          Inc.Written.front() == '<',
          syntax::FileRange(SM, SynthesizedFilenameTok.getLocation(),
                            SynthesizedFilenameTok.getEndLoc())
              .toCharRange(SM),
          File, "SearchPath", "RelPath",
          /*SuggestedModule=*/nullptr, /*ModuleImported=*/false, Inc.FileKind);
      if (File)
        Delegate->FileSkipped(*File, SynthesizedFilenameTok, Inc.FileKind);
    }
  }
 
  const std::vector<Inclusion> Includes;
  const MainFileMacros Macros;
  PPCallbacks *Delegate;
  const SourceManager &SM;
  Preprocessor &PP;
  std::vector<syntax::Token> MainFileTokens;
};
 
std::vector<Diag> getIncludeCleanerDiags(ParsedAST &AST, llvm::StringRef Code,
                                         const ThreadsafeFS &TFS) {
  auto &Cfg = Config::current();
  if (Cfg.Diagnostics.SuppressAll)
    return {};
  bool SuppressMissing =
      Cfg.Diagnostics.Suppress.contains("missing-includes") ||
      Cfg.Diagnostics.MissingIncludes == Config::IncludesPolicy::None;
  bool SuppressUnused =
      Cfg.Diagnostics.Suppress.contains("unused-includes") ||
      Cfg.Diagnostics.UnusedIncludes == Config::IncludesPolicy::None;
  if (SuppressMissing && SuppressUnused)
    return {};
  auto Findings = computeIncludeCleanerFindings(
      AST, Cfg.Diagnostics.Includes.AnalyzeAngledIncludes);
  if (SuppressMissing)
    Findings.MissingIncludes.clear();
  if (SuppressUnused)
    Findings.UnusedIncludes.clear();
  return issueIncludeCleanerDiagnostics(
      AST, Code, Findings, TFS, Cfg.Diagnostics.Includes.IgnoreHeader,
      Cfg.Style.AngledHeaders, Cfg.Style.QuotedHeaders);
}
 
} // namespace
 
std::optional<ParsedAST>
ParsedAST::build(llvm::StringRef Filename, const ParseInputs &Inputs,
                 std::unique_ptr<clang::CompilerInvocation> CI,
                 llvm::ArrayRef<Diag> CompilerInvocationDiags,
                 std::shared_ptr<const PreambleData> Preamble) {
  trace::Span Tracer("BuildAST");
  SPAN_ATTACH(Tracer, "File", Filename);
  const Config &Cfg = Config::current();
 
  auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
  if (Preamble && Preamble->StatCache)
    VFS = Preamble->StatCache->getConsumingFS(std::move(VFS));
 
  assert(CI);
 
  if (CI->getFrontendOpts().Inputs.size() > 0) {
    auto Lang = CI->getFrontendOpts().Inputs[0].getKind().getLanguage();
    if (Lang == Language::Asm || Lang == Language::LLVM_IR) {
      elog("Clangd does not support assembly or IR source files");
      return std::nullopt;
    }
  }
 
  // Command-line parsing sets DisableFree to true by default, but we don't want
  // to leak memory in clangd.
  CI->getFrontendOpts().DisableFree = false;
  const PrecompiledPreamble *PreamblePCH =
      Preamble ? &Preamble->Preamble : nullptr;
 
  // This is on-by-default in windows to allow parsing SDK headers, but it
  // breaks many features. Disable it for the main-file (not preamble).
  CI->getLangOpts().DelayedTemplateParsing = false;
 
  std::vector<std::unique_ptr<FeatureModule::ASTListener>> ASTListeners;
  if (Inputs.FeatureModules) {
    for (auto &M : *Inputs.FeatureModules) {
      if (auto Listener = M.astListeners())
        ASTListeners.emplace_back(std::move(Listener));
    }
  }
  StoreDiags ASTDiags;
  ASTDiags.setDiagCallback(
      [&ASTListeners](const clang::Diagnostic &D, clangd::Diag &Diag) {
        for (const auto &L : ASTListeners)
          L->sawDiagnostic(D, Diag);
      });
  ASTDiags.setDiagFinalizer([&ASTListeners](clangd::Diag &Diag) {
    for (const auto &L : ASTListeners)
      L->finalizeDiagnostic(Diag);
  });
 
  // Adjust header search options to load the built module files recorded
  // in RequiredModules.
  if (Preamble && Preamble->RequiredModules)
    Preamble->RequiredModules->adjustHeaderSearchOptions(
        CI->getHeaderSearchOpts());
 
  std::optional<PreamblePatch> Patch;
  // We might use an ignoring diagnostic consumer if they are going to be
  // dropped later on to not pay for extra latency by processing them.
  DiagnosticConsumer *DiagConsumer = &ASTDiags;
  IgnoreDiagnostics DropDiags;
  if (Preamble) {
    Patch = PreamblePatch::createFullPatch(Filename, Inputs, *Preamble);
    Patch->apply(*CI);
  }
  auto Clang = prepareCompilerInstance(
      std::move(CI), Inputs.Opts.SkipPreambleBuild ? nullptr : PreamblePCH,
      llvm::MemoryBuffer::getMemBufferCopy(Inputs.Contents, Filename), VFS,
      *DiagConsumer);
 
  if (!Clang) {
    // The last diagnostic contains information about the reason of this
    // failure.
    std::vector<Diag> Diags(ASTDiags.take());
    elog("Failed to prepare a compiler instance: {0}",
         !Diags.empty() ? static_cast<DiagBase &>(Diags.back()).Message
                        : "unknown error");
    return std::nullopt;
  }
  auto Action = std::make_unique<ClangdFrontendAction>();
  for (const auto &L : ASTListeners)
    L->beforeBeginSourceFile(*Clang);
  const FrontendInputFile &MainInput = Clang->getFrontendOpts().Inputs[0];
  if (!Action->BeginSourceFile(*Clang, MainInput)) {
    elog("BeginSourceFile() failed when building AST for {0}",
         MainInput.getFile());
    return std::nullopt;
  }
  // If we saw an include guard in the preamble section of the main file,
  // mark the main-file as include-guarded.
  // This information is part of the HeaderFileInfo but is not loaded from the
  // preamble as the file's size is part of its identity and may have changed.
  // (The rest of HeaderFileInfo is not relevant for our purposes).
  if (Preamble && Preamble->MainIsIncludeGuarded) {
    const SourceManager &SM = Clang->getSourceManager();
    OptionalFileEntryRef MainFE = SM.getFileEntryRefForID(SM.getMainFileID());
    Clang->getPreprocessor().getHeaderSearchInfo().MarkFileIncludeOnce(*MainFE);
  }
 
  // Must outlive FixIncludes.
  auto BuildDir = VFS->getCurrentWorkingDirectory();
  std::optional<IncludeFixer> FixIncludes;
  llvm::DenseMap<diag::kind, DiagnosticsEngine::Level> OverriddenSeverity;
  // Clang only corrects typos for use of undeclared functions in C if that
  // use is an error. Include fixer relies on typo correction, so pretend
  // this is an error. (The actual typo correction is nice too).
  // We restore the original severity in the level adjuster.
  // FIXME: It would be better to have a real API for this, but what?
  for (auto ID : {diag::ext_implicit_function_decl_c99,
                  diag::ext_implicit_lib_function_decl,
                  diag::ext_implicit_lib_function_decl_c99,
                  diag::warn_implicit_function_decl}) {
    OverriddenSeverity.try_emplace(
        ID, Clang->getDiagnostics().getDiagnosticLevel(ID, SourceLocation()));
    Clang->getDiagnostics().setSeverity(ID, diag::Severity::Error,
                                        SourceLocation());
  }
  ASTDiags.setLevelAdjuster(
      [&](DiagnosticsEngine::Level Level, const clang::Diagnostic &Info) {
        auto It = OverriddenSeverity.find(Info.getID());
        return It == OverriddenSeverity.end() ? Level : It->second;
      });
 
  // Add IncludeFixer which can recover diagnostics caused by missing includes
  // (e.g. incomplete type) and attach include insertion fixes to diagnostics.
  if (Inputs.Index && !BuildDir.getError()) {
    auto Style =
        getFormatStyleForFile(Filename, Inputs.Contents, *Inputs.TFS, false);
    auto Inserter = std::make_shared<IncludeInserter>(
        Filename, Inputs.Contents, Style, BuildDir.get(),
        &Clang->getPreprocessor().getHeaderSearchInfo(),
        Cfg.Style.QuotedHeaders, Cfg.Style.AngledHeaders);
    ArrayRef<Inclusion> MainFileIncludes;
    if (Preamble) {
      MainFileIncludes = Preamble->Includes.MainFileIncludes;
      for (const auto &Inc : Preamble->Includes.MainFileIncludes)
        Inserter->addExisting(Inc);
    }
    // FIXME: Consider piping through ASTSignals to fetch this to handle the
    // case where a header file contains ObjC decls but no #imports.
    Symbol::IncludeDirective Directive =
        Inputs.Opts.ImportInsertions
            ? preferredIncludeDirective(Filename, Clang->getLangOpts(),
                                        MainFileIncludes, {})
            : Symbol::Include;
    FixIncludes.emplace(Filename, Inserter, *Inputs.Index,
                        /*IndexRequestLimit=*/5, Directive);
    ASTDiags.contributeFixes([&FixIncludes](DiagnosticsEngine::Level Level,
                                            const clang::Diagnostic &Info) {
      return FixIncludes->fix(Level, Info);
    });
    Clang->setExternalSemaSource(FixIncludes->unresolvedNameRecorder());
  }
 
  // ReplayPreamble must capture callbacks installed by feature modules.
  for (const auto &L : ASTListeners)
    L->beforePPCallbacks(*Clang);
 
  IncludeStructure Includes;
  include_cleaner::PragmaIncludes PI;
  // If we are using a preamble, copy existing includes.
  if (Preamble) {
    Includes = Preamble->Includes;
    Includes.MainFileIncludes = Patch->preambleIncludes();
    // Replay the preamble includes so that clang-tidy checks can see them.
    ReplayPreamble::attach(Patch->preambleIncludes(), Patch->mainFileMacros(),
                           *Clang, Patch->modifiedBounds());
    PI = *Preamble->Pragmas;
  }
  // Important: collectIncludeStructure is registered *after* ReplayPreamble!
  // Otherwise we would collect the replayed includes again...
  // (We can't *just* use the replayed includes, they don't have Resolved path).
  Includes.collect(*Clang);
  // Same for pragma-includes, we're already inheriting preamble includes, so we
  // should only receive callbacks for non-preamble mainfile includes.
  PI.record(*Clang);
  // Copy over the macros in the preamble region of the main file, and combine
  // with non-preamble macros below.
  MainFileMacros Macros;
  std::vector<PragmaMark> Marks;
  if (Preamble) {
    Macros = Patch->mainFileMacros();
    Marks = Patch->marks();
  }
  auto &PP = Clang->getPreprocessor();
  auto MacroCollector = std::make_unique<CollectMainFileMacros>(PP, Macros);
  auto *MacroCollectorPtr = MacroCollector.get(); // so we can call doneParse()
  PP.addPPCallbacks(std::move(MacroCollector));
 
  PP.addPPCallbacks(
      collectPragmaMarksCallback(Clang->getSourceManager(), Marks));
 
  // FIXME: Attach a comment handler to take care of
  // keep/export/no_include etc. IWYU pragmas.
 
  // Collect tokens of the main file.
  syntax::TokenCollector CollectTokens(PP);
 
  // To remain consistent with preamble builds, these callbacks must be called
  // exactly here, after preprocessor is initialized and BeginSourceFile() was
  // called already.
  for (const auto &L : ASTListeners)
    L->beforeExecute(*Clang);
 
  if (llvm::Error Err = Action->Execute())
    log("Execute() failed when building AST for {0}: {1}", MainInput.getFile(),
        toString(std::move(Err)));
 
  // Disable the macro collector for the remainder of this function, e.g.
  // clang-tidy checkers.
  MacroCollectorPtr->doneParse();
 
  // We have to consume the tokens before running clang-tidy to avoid collecting
  // tokens from running the preprocessor inside the checks (only
  // modernize-use-trailing-return-type does that today).
  syntax::TokenBuffer Tokens = std::move(CollectTokens).consume();
  // Makes SelectionTree build much faster.
  Tokens.indexExpandedTokens();
  std::vector<Decl *> ParsedDecls = Action->takeTopLevelDecls();
  // AST traversals should exclude the preamble, to avoid performance cliffs.
  Clang->getASTContext().setTraversalScope(ParsedDecls);
  for (const auto &L : ASTListeners)
    L->afterExecute(*Clang);
 
  // XXX: This is messy: clang-tidy checks flush some diagnostics at EOF.
  // However Action->EndSourceFile() would destroy the ASTContext!
  // So just inform the preprocessor of EOF, while keeping everything alive.
  PP.EndSourceFile();
  // UnitDiagsConsumer is local, we can not store it in CompilerInstance that
  // has a longer lifetime.
  Clang->getDiagnostics().setClient(new IgnoreDiagnostics);
  // CompilerInstance won't run this callback, do it directly.
  ASTDiags.EndSourceFile();
 
  std::vector<Diag> Diags = CompilerInvocationDiags;
  // FIXME: Also skip generation of diagnostics altogether to speed up ast
  // builds when we are patching a stale preamble.
  // Add diagnostics from the preamble, if any.
  if (Preamble)
    llvm::append_range(Diags, Patch->patchedDiags());
  // Finally, add diagnostics coming from the AST.
  {
    std::vector<Diag> D = ASTDiags.take();
    Diags.insert(Diags.end(), D.begin(), D.end());
  }
  ParsedAST Result(Filename, Inputs.Version, std::move(Preamble),
                   std::move(Clang), std::move(Action), std::move(Tokens),
                   std::move(Macros), std::move(Marks), std::move(ParsedDecls),
                   std::move(Diags), std::move(Includes), std::move(PI));
  llvm::move(getIncludeCleanerDiags(Result, Inputs.Contents, *Inputs.TFS),
             std::back_inserter(Result.Diags));
  return std::move(Result);
}
 
ParsedAST::ParsedAST(ParsedAST &&Other) = default;
 
ParsedAST &ParsedAST::operator=(ParsedAST &&Other) = default;
 
ParsedAST::~ParsedAST() {
  if (Action) {
    // We already notified the PP of end-of-file earlier, so detach it first.
    // We must keep it alive until after EndSourceFile(), Sema relies on this.
    auto PP = Clang->getPreprocessorPtr(); // Keep PP alive for now.
    Clang->setPreprocessor(nullptr);       // Detach so we don't send EOF again.
    Action->EndSourceFile();               // Destroy ASTContext and Sema.
    // Now Sema is gone, it's safe for PP to go out of scope.
  }
}
 
ASTContext &ParsedAST::getASTContext() { return Clang->getASTContext(); }
 
const ASTContext &ParsedAST::getASTContext() const {
  return Clang->getASTContext();
}
 
Sema &ParsedAST::getSema() { return Clang->getSema(); }
 
Preprocessor &ParsedAST::getPreprocessor() { return Clang->getPreprocessor(); }
 
std::shared_ptr<Preprocessor> ParsedAST::getPreprocessorPtr() {
  return Clang->getPreprocessorPtr();
}
 
const Preprocessor &ParsedAST::getPreprocessor() const {
  return Clang->getPreprocessor();
}
 
llvm::ArrayRef<Decl *> ParsedAST::getLocalTopLevelDecls() {
  return LocalTopLevelDecls;
}
 
llvm::ArrayRef<const Decl *> ParsedAST::getLocalTopLevelDecls() const {
  return LocalTopLevelDecls;
}
 
const MainFileMacros &ParsedAST::getMacros() const { return Macros; }
const std::vector<PragmaMark> &ParsedAST::getMarks() const { return Marks; }
 
std::size_t ParsedAST::getUsedBytes() const {
  auto &AST = getASTContext();
  // FIXME(ibiryukov): we do not account for the dynamically allocated part of
  // Message and Fixes inside each diagnostic.
  std::size_t Total =
      clangd::getUsedBytes(LocalTopLevelDecls) + clangd::getUsedBytes(Diags);
 
  // FIXME: the rest of the function is almost a direct copy-paste from
  // libclang's clang_getCXTUResourceUsage. We could share the implementation.
 
  // Sum up various allocators inside the ast context and the preprocessor.
  Total += AST.getASTAllocatedMemory();
  Total += AST.getSideTableAllocatedMemory();
  Total += AST.Idents.getAllocator().getTotalMemory();
  Total += AST.Selectors.getTotalMemory();
 
  Total += AST.getSourceManager().getContentCacheSize();
  Total += AST.getSourceManager().getDataStructureSizes();
  Total += AST.getSourceManager().getMemoryBufferSizes().malloc_bytes;
 
  if (ExternalASTSource *Ext = AST.getExternalSource())
    Total += Ext->getMemoryBufferSizes().malloc_bytes;
 
  const Preprocessor &PP = getPreprocessor();
  Total += PP.getTotalMemory();
  if (PreprocessingRecord *PRec = PP.getPreprocessingRecord())
    Total += PRec->getTotalMemory();
  Total += PP.getHeaderSearchInfo().getTotalMemory();
 
  return Total;
}
 
const IncludeStructure &ParsedAST::getIncludeStructure() const {
  return Includes;
}
 
ParsedAST::ParsedAST(PathRef TUPath, llvm::StringRef Version,
                     std::shared_ptr<const PreambleData> Preamble,
                     std::unique_ptr<CompilerInstance> Clang,
                     std::unique_ptr<FrontendAction> Action,
                     syntax::TokenBuffer Tokens, MainFileMacros Macros,
                     std::vector<PragmaMark> Marks,
                     std::vector<Decl *> LocalTopLevelDecls,
                     std::vector<Diag> Diags, IncludeStructure Includes,
                     include_cleaner::PragmaIncludes PI)
    : TUPath(TUPath), Version(Version), Preamble(std::move(Preamble)),
      Clang(std::move(Clang)), Action(std::move(Action)),
      Tokens(std::move(Tokens)), Macros(std::move(Macros)),
      Marks(std::move(Marks)), Diags(std::move(Diags)),
      LocalTopLevelDecls(std::move(LocalTopLevelDecls)),
      Includes(std::move(Includes)), PI(std::move(PI)),
      Resolver(std::make_unique<HeuristicResolver>(getASTContext())) {
  assert(this->Clang);
  assert(this->Action);
}
 
const include_cleaner::PragmaIncludes &ParsedAST::getPragmaIncludes() const {
  return PI;
}
 
std::optional<llvm::StringRef> ParsedAST::preambleVersion() const {
  if (!Preamble)
    return std::nullopt;
  return llvm::StringRef(Preamble->Version);
}
 
llvm::ArrayRef<Diag> ParsedAST::getDiagnostics() const { return Diags; }
} // namespace clangd
} // namespace clang