//===- VerifyDiagnosticConsumer.cpp - Verifying Diagnostic Client ---------===//

//

// 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

//

//===----------------------------------------------------------------------===//

//

// This is a concrete diagnostic client, which buffers the diagnostic messages.

//

//===----------------------------------------------------------------------===//

#include "clang/Frontend/VerifyDiagnosticConsumer.h"

#include "clang/Basic/CharInfo.h"

#include "clang/Basic/Diagnostic.h"

#include "clang/Basic/DiagnosticOptions.h"

#include "clang/Basic/FileManager.h"

#include "clang/Basic/LLVM.h"

#include "clang/Basic/SourceLocation.h"

#include "clang/Basic/SourceManager.h"

#include "clang/Basic/TokenKinds.h"

#include "clang/Frontend/FrontendDiagnostic.h"

#include "clang/Frontend/TextDiagnosticBuffer.h"

#include "clang/Lex/HeaderSearch.h"

#include "clang/Lex/Lexer.h"

#include "clang/Lex/PPCallbacks.h"

#include "clang/Lex/Preprocessor.h"

#include "clang/Lex/Token.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/ADT/SmallPtrSet.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/ADT/Twine.h"

#include "llvm/Support/ErrorHandling.h"

#include "llvm/Support/Regex.h"

#include "llvm/Support/raw_ostream.h"

#include <algorithm>

#include <cassert>

#include <cstddef>

#include <cstring>

#include <iterator>

#include <memory>

#include <string>

#include <utility>

#include <vector>

using namespace clang;

using Directive = VerifyDiagnosticConsumer::Directive;

using DirectiveList = VerifyDiagnosticConsumer::DirectiveList;

using ExpectedData = VerifyDiagnosticConsumer::ExpectedData;

#ifndef NDEBUG

namespace {

class VerifyFileTracker : public PPCallbacks {

  VerifyDiagnosticConsumer &Verify;

  SourceManager &SM;

public:

  VerifyFileTracker(VerifyDiagnosticConsumer &Verify, SourceManager &SM)

      : Verify(Verify), SM(SM) {}

  /// Hook into the preprocessor and update the list of parsed

  /// files when the preprocessor indicates a new file is entered.

  void FileChanged(SourceLocation Loc, FileChangeReason Reason,

                   SrcMgr::CharacteristicKind FileType,

                   FileID PrevFID) override {

    Verify.UpdateParsedFileStatus(SM, SM.getFileID(Loc),

                                  VerifyDiagnosticConsumer::IsParsed);

  }

};

} // namespace

#endif

//===----------------------------------------------------------------------===//

// Checking diagnostics implementation.

//===----------------------------------------------------------------------===//

using DiagList = TextDiagnosticBuffer::DiagList;

using const_diag_iterator = TextDiagnosticBuffer::const_iterator;

namespace {

/// StandardDirective - Directive with string matching.

class StandardDirective : public Directive {

public:

  StandardDirective(SourceLocation DirectiveLoc, SourceLocation DiagnosticLoc,

                    bool MatchAnyFileAndLine, bool MatchAnyLine, StringRef Text,

                    unsigned Min, unsigned Max)

      : Directive(DirectiveLoc, DiagnosticLoc, MatchAnyFileAndLine,

                  MatchAnyLine, Text, Min, Max) {}

  bool isValid(std::string &Error) override {

    // all strings are considered valid; even empty ones

    return true;

  }

  bool match(StringRef S) override { return S.contains(Text); }

};

/// RegexDirective - Directive with regular-expression matching.

class RegexDirective : public Directive {

public:

  RegexDirective(SourceLocation DirectiveLoc, SourceLocation DiagnosticLoc,

                 bool MatchAnyFileAndLine, bool MatchAnyLine, StringRef Text,

                 unsigned Min, unsigned Max, StringRef RegexStr)

      : Directive(DirectiveLoc, DiagnosticLoc, MatchAnyFileAndLine,

                  MatchAnyLine, Text, Min, Max),

        Regex(RegexStr) {}

  bool isValid(std::string &Error) override {

    return Regex.isValid(Error);

  }

  bool match(StringRef S) override {

    return Regex.match(S);

  }

private:

  llvm::Regex Regex;

};

class ParseHelper

{

public:

  ParseHelper(StringRef S)

      : Begin(S.begin()), End(S.end()), C(Begin), P(Begin) {}

  // Return true if string literal is next.

  bool Next(StringRef S) {

    P = C;

    PEnd = C + S.size();

    if (PEnd > End)

      return false;

    return memcmp(P, S.data(), S.size()) == 0;

  }

  // Return true if number is next.

  // Output N only if number is next.

  bool Next(unsigned &N) {

    unsigned TMP = 0;

    P = C;

    PEnd = P;

    for (; PEnd < End && *PEnd >= '0' && *PEnd <= '9'; ++PEnd) {

      TMP *= 10;

      TMP += *PEnd - '0';

    }

    if (PEnd == C)

      return false;

    N = TMP;

    return true;

  }

  // Return true if a marker is next.

  // A marker is the longest match for /#[A-Za-z0-9_-]+/.

  bool NextMarker() {

    P = C;

    if (P == End || *P != '#')

      return false;

    PEnd = P;

    ++PEnd;

    while ((isAlphanumeric(*PEnd) || *PEnd == '-' || *PEnd == '_') &&

           PEnd < End)

      ++PEnd;

    return PEnd > P + 1;

  }

  // Return true if string literal S is matched in content.

  // When true, P marks begin-position of the match, and calling Advance sets C

  // to end-position of the match.

  // If S is the empty string, then search for any letter instead (makes sense

  // with FinishDirectiveToken=true).

  // If EnsureStartOfWord, then skip matches that don't start a new word.

  // If FinishDirectiveToken, then assume the match is the start of a comment

  // directive for -verify, and extend the match to include the entire first

  // token of that directive.

  bool Search(StringRef S, bool EnsureStartOfWord = false,

              bool FinishDirectiveToken = false) {

    do {

      if (!S.empty()) {

        P = std::search(C, End, S.begin(), S.end());

        PEnd = P + S.size();

      }

      else {

        P = C;

        while (P != End && !isLetter(*P))

          ++P;

        PEnd = P + 1;

      }

      if (P == End)

        break;

      // If not start of word but required, skip and search again.

      if (EnsureStartOfWord

               // Check if string literal starts a new word.

          && !(P == Begin || isWhitespace(P[-1])

               // Or it could be preceded by the start of a comment.

               || (P > (Begin + 1) && (P[-1] == '/' || P[-1] == '*')

                                   &&  P[-2] == '/')))

        continue;

      if (FinishDirectiveToken) {

        while (PEnd != End && (isAlphanumeric(*PEnd)

                               || *PEnd == '-' || *PEnd == '_'))

          ++PEnd;

        // Put back trailing digits and hyphens to be parsed later as a count

        // or count range.  Because -verify prefixes must start with letters,

        // we know the actual directive we found starts with a letter, so

        // we won't put back the entire directive word and thus record an empty

        // string.

        assert(isLetter(*P) && "-verify prefix must start with a letter");

        while (isDigit(PEnd[-1]) || PEnd[-1] == '-')

          --PEnd;

      }

      return true;

    } while (Advance());

    return false;

  }

  // Return true if a CloseBrace that closes the OpenBrace at the current nest

  // level is found. When true, P marks begin-position of CloseBrace.

  bool SearchClosingBrace(StringRef OpenBrace, StringRef CloseBrace) {

    unsigned Depth = 1;

    P = C;

    while (P < End) {

      StringRef S(P, End - P);

      if (S.starts_with(OpenBrace)) {

        ++Depth;

        P += OpenBrace.size();

      } else if (S.starts_with(CloseBrace)) {

        --Depth;

        if (Depth == 0) {

          PEnd = P + CloseBrace.size();

          return true;

        }

        P += CloseBrace.size();

      } else {

        ++P;

      }

    }

    return false;

  }

  // Advance 1-past previous next/search.

  // Behavior is undefined if previous next/search failed.

  bool Advance() {

    C = PEnd;

    return C < End;

  }

  // Return the text matched by the previous next/search.

  // Behavior is undefined if previous next/search failed.

  StringRef Match() { return StringRef(P, PEnd - P); }

  // Skip zero or more whitespace.

  void SkipWhitespace() {

    for (; C < End && isWhitespace(*C); ++C)

      ;

  }

  // Return true if EOF reached.

  bool Done() {

    return !(C < End);

  }

  // Beginning of expected content.

  const char * const Begin;

  // End of expected content (1-past).

  const char * const End;

  // Position of next char in content.

  const char *C;

  // Previous next/search subject start.

  const char *P;

private:

  // Previous next/search subject end (1-past).

  const char *PEnd = nullptr;

};

// The information necessary to create a directive.

struct UnattachedDirective {

  DirectiveList *DL = nullptr;

  bool RegexKind = false;

  SourceLocation DirectivePos, ContentBegin;

  std::string Text;

  unsigned Min = 1, Max = 1;

};

// Attach the specified directive to the line of code indicated by

// \p ExpectedLoc.

void attachDirective(DiagnosticsEngine &Diags, const UnattachedDirective &UD,

                     SourceLocation ExpectedLoc,

                     bool MatchAnyFileAndLine = false,

                     bool MatchAnyLine = false) {

  // Construct new directive.

  std::unique_ptr<Directive> D = Directive::create(

      UD.RegexKind, UD.DirectivePos, ExpectedLoc, MatchAnyFileAndLine,

      MatchAnyLine, UD.Text, UD.Min, UD.Max);

  std::string Error;

  if (!D->isValid(Error)) {

    Diags.Report(UD.ContentBegin, diag::err_verify_invalid_content)

      << (UD.RegexKind ? "regex" : "string") << Error;

  }

  UD.DL->push_back(std::move(D));

}

} // anonymous

// Tracker for markers in the input files. A marker is a comment of the form

//

//   n = 123; // #123

//

// ... that can be referred to by a later expected-* directive:

//

//   // expected-error@#123 {{undeclared identifier 'n'}}

//

// Marker declarations must be at the start of a comment or preceded by

// whitespace to distinguish them from uses of markers in directives.

class VerifyDiagnosticConsumer::MarkerTracker {

  DiagnosticsEngine &Diags;

  struct Marker {

    SourceLocation DefLoc;

    SourceLocation RedefLoc;

    SourceLocation UseLoc;

  };

  llvm::StringMap<Marker> Markers;

  // Directives that couldn't be created yet because they name an unknown

  // marker.

  llvm::StringMap<llvm::SmallVector<UnattachedDirective, 2>> DeferredDirectives;

public:

  MarkerTracker(DiagnosticsEngine &Diags) : Diags(Diags) {}

  // Register a marker.

  void addMarker(StringRef MarkerName, SourceLocation Pos) {

    auto InsertResult = Markers.insert(

        {MarkerName, Marker{Pos, SourceLocation(), SourceLocation()}});

    Marker &M = InsertResult.first->second;

    if (!InsertResult.second) {

      // Marker was redefined.

      M.RedefLoc = Pos;

    } else {

      // First definition: build any deferred directives.

      auto Deferred = DeferredDirectives.find(MarkerName);

      if (Deferred != DeferredDirectives.end()) {

        for (auto &UD : Deferred->second) {

          if (M.UseLoc.isInvalid())

            M.UseLoc = UD.DirectivePos;

          attachDirective(Diags, UD, Pos);

        }

        DeferredDirectives.erase(Deferred);

      }

    }

  }

  // Register a directive at the specified marker.

  void addDirective(StringRef MarkerName, const UnattachedDirective &UD) {

    auto MarkerIt = Markers.find(MarkerName);

    if (MarkerIt != Markers.end()) {

      Marker &M = MarkerIt->second;

      if (M.UseLoc.isInvalid())

        M.UseLoc = UD.DirectivePos;

      return attachDirective(Diags, UD, M.DefLoc);

    }

    DeferredDirectives[MarkerName].push_back(UD);

  }

  // Ensure we have no remaining deferred directives, and no

  // multiply-defined-and-used markers.

  void finalize() {

    for (auto &MarkerInfo : Markers) {

      StringRef Name = MarkerInfo.first();

      Marker &M = MarkerInfo.second;

      if (M.RedefLoc.isValid() && M.UseLoc.isValid()) {

        Diags.Report(M.UseLoc, diag::err_verify_ambiguous_marker) << Name;

        Diags.Report(M.DefLoc, diag::note_verify_ambiguous_marker) << Name;

        Diags.Report(M.RedefLoc, diag::note_verify_ambiguous_marker) << Name;

      }

    }

    for (auto &DeferredPair : DeferredDirectives) {

      Diags.Report(DeferredPair.second.front().DirectivePos,

                   diag::err_verify_no_such_marker)

          << DeferredPair.first();

    }

  }

};

/// ParseDirective - Go through the comment and see if it indicates expected

/// diagnostics. If so, then put them in the appropriate directive list.

///

/// Returns true if any valid directives were found.

static bool ParseDirective(StringRef S, ExpectedData *ED, SourceManager &SM,

                           Preprocessor *PP, SourceLocation Pos,

                           VerifyDiagnosticConsumer::DirectiveStatus &Status,

                           VerifyDiagnosticConsumer::MarkerTracker &Markers) {

  DiagnosticsEngine &Diags = PP ? PP->getDiagnostics() : SM.getDiagnostics();

  // First, scan the comment looking for markers.

  for (ParseHelper PH(S); !PH.Done();) {

    if (!PH.Search("#", true))

      break;

    PH.C = PH.P;

    if (!PH.NextMarker()) {

      PH.Next("#");

      PH.Advance();

      continue;

    }

    PH.Advance();

    Markers.addMarker(PH.Match(), Pos);

  }

  // A single comment may contain multiple directives.

  bool FoundDirective = false;

  for (ParseHelper PH(S); !PH.Done();) {

    // Search for the initial directive token.

    // If one prefix, save time by searching only for its directives.

    // Otherwise, search for any potential directive token and check it later.

    const auto &Prefixes = Diags.getDiagnosticOptions().VerifyPrefixes;

    if (!(Prefixes.size() == 1 ? PH.Search(*Prefixes.begin(), true, true)

                               : PH.Search("", true, true)))

      break;

    StringRef DToken = PH.Match();

    PH.Advance();

    // Default directive kind.

    UnattachedDirective D;

    const char *KindStr = "string";

    // Parse the initial directive token in reverse so we can easily determine

    // its exact actual prefix.  If we were to parse it from the front instead,

    // it would be harder to determine where the prefix ends because there

    // might be multiple matching -verify prefixes because some might prefix

    // others.

    // Regex in initial directive token: -re

    if (DToken.ends_with("-re")) {

      D.RegexKind = true;

      KindStr = "regex";

      DToken = DToken.substr(0, DToken.size()-3);

    }

    // Type in initial directive token: -{error|warning|note|no-diagnostics}

    bool NoDiag = false;

    StringRef DType;

    if (DToken.ends_with(DType = "-error"))

      D.DL = ED ? &ED->Errors : nullptr;

    else if (DToken.ends_with(DType = "-warning"))

      D.DL = ED ? &ED->Warnings : nullptr;

    else if (DToken.ends_with(DType = "-remark"))

      D.DL = ED ? &ED->Remarks : nullptr;

    else if (DToken.ends_with(DType = "-note"))

      D.DL = ED ? &ED->Notes : nullptr;

    else if (DToken.ends_with(DType = "-no-diagnostics")) {

      NoDiag = true;

      if (D.RegexKind)

        continue;

    } else

      continue;

    DToken = DToken.substr(0, DToken.size()-DType.size());

    // What's left in DToken is the actual prefix.  That might not be a -verify

    // prefix even if there is only one -verify prefix (for example, the full

    // DToken is foo-bar-warning, but foo is the only -verify prefix).

    if (!std::binary_search(Prefixes.begin(), Prefixes.end(), DToken))

      continue;

    if (NoDiag) {

      if (Status == VerifyDiagnosticConsumer::HasOtherExpectedDirectives)

        Diags.Report(Pos, diag::err_verify_invalid_no_diags)

          << /*IsExpectedNoDiagnostics=*/true;

      else

        Status = VerifyDiagnosticConsumer::HasExpectedNoDiagnostics;

      continue;

    }

    if (Status == VerifyDiagnosticConsumer::HasExpectedNoDiagnostics) {

      Diags.Report(Pos, diag::err_verify_invalid_no_diags)

        << /*IsExpectedNoDiagnostics=*/false;

      continue;

    }

    Status = VerifyDiagnosticConsumer::HasOtherExpectedDirectives;

    // If a directive has been found but we're not interested

    // in storing the directive information, return now.

    if (!D.DL)

      return true;

    // Next optional token: @

    SourceLocation ExpectedLoc;

    StringRef Marker;

    bool MatchAnyFileAndLine = false;

    bool MatchAnyLine = false;

    if (!PH.Next("@")) {

      ExpectedLoc = Pos;

    } else {

      PH.Advance();

      unsigned Line = 0;

      bool FoundPlus = PH.Next("+");

      if (FoundPlus || PH.Next("-")) {

        // Relative to current line.

        PH.Advance();

        bool Invalid = false;

        unsigned ExpectedLine = SM.getSpellingLineNumber(Pos, &Invalid);

        if (!Invalid && PH.Next(Line) && (FoundPlus || Line < ExpectedLine)) {

          if (FoundPlus) ExpectedLine += Line;

          else ExpectedLine -= Line;

          ExpectedLoc = SM.translateLineCol(SM.getFileID(Pos), ExpectedLine, 1);

        }

      } else if (PH.Next(Line)) {

        // Absolute line number.

        if (Line > 0)

          ExpectedLoc = SM.translateLineCol(SM.getFileID(Pos), Line, 1);

      } else if (PH.NextMarker()) {

        Marker = PH.Match();

      } else if (PP && PH.Search(":")) {

        // Specific source file.

        StringRef Filename(PH.C, PH.P-PH.C);

        PH.Advance();

        if (Filename == "*") {

          MatchAnyFileAndLine = true;

          if (!PH.Next("*")) {

            Diags.Report(Pos.getLocWithOffset(PH.C - PH.Begin),

                         diag::err_verify_missing_line)

                << "'*'";

            continue;

          }

          MatchAnyLine = true;

          ExpectedLoc = SourceLocation();

        } else {

          // Lookup file via Preprocessor, like a #include.

          OptionalFileEntryRef File =

              PP->LookupFile(Pos, Filename, false, nullptr, nullptr, nullptr,

                             nullptr, nullptr, nullptr, nullptr, nullptr);

          if (!File) {

            Diags.Report(Pos.getLocWithOffset(PH.C - PH.Begin),

                         diag::err_verify_missing_file)

                << Filename << KindStr;

            continue;

          }

          FileID FID = SM.translateFile(*File);

          if (FID.isInvalid())

            FID = SM.createFileID(*File, Pos, SrcMgr::C_User);

          if (PH.Next(Line) && Line > 0)

            ExpectedLoc = SM.translateLineCol(FID, Line, 1);

          else if (PH.Next("*")) {

            MatchAnyLine = true;

            ExpectedLoc = SM.translateLineCol(FID, 1, 1);

          }

        }

      } else if (PH.Next("*")) {

        MatchAnyLine = true;

        ExpectedLoc = SourceLocation();

      }

      if (ExpectedLoc.isInvalid() && !MatchAnyLine && Marker.empty()) {

        Diags.Report(Pos.getLocWithOffset(PH.C-PH.Begin),

                     diag::err_verify_missing_line) << KindStr;

        continue;

      }

      PH.Advance();

    }

    // Skip optional whitespace.

    PH.SkipWhitespace();

    // Next optional token: positive integer or a '+'.

    if (PH.Next(D.Min)) {

      PH.Advance();

      // A positive integer can be followed by a '+' meaning min

      // or more, or by a '-' meaning a range from min to max.

      if (PH.Next("+")) {

        D.Max = Directive::MaxCount;

        PH.Advance();

      } else if (PH.Next("-")) {

        PH.Advance();

        if (!PH.Next(D.Max) || D.Max < D.Min) {

          Diags.Report(Pos.getLocWithOffset(PH.C-PH.Begin),

                       diag::err_verify_invalid_range) << KindStr;

          continue;

        }

        PH.Advance();

      } else {

        D.Max = D.Min;

      }

    } else if (PH.Next("+")) {

      // '+' on its own means "1 or more".

      D.Max = Directive::MaxCount;

      PH.Advance();

    }

    // Skip optional whitespace.

    PH.SkipWhitespace();

    // Next token: {{

    if (!PH.Next("{{")) {

      Diags.Report(Pos.getLocWithOffset(PH.C-PH.Begin),

                   diag::err_verify_missing_start) << KindStr;

      continue;

    }

    llvm::SmallString<8> CloseBrace("}}");

    const char *const DelimBegin = PH.C;

    PH.Advance();

    // Count the number of opening braces for `string` kinds

    for (; !D.RegexKind && PH.Next("{"); PH.Advance())

      CloseBrace += '}';

    const char* const ContentBegin = PH.C; // mark content begin

    // Search for closing brace

    StringRef OpenBrace(DelimBegin, ContentBegin - DelimBegin);

    if (!PH.SearchClosingBrace(OpenBrace, CloseBrace)) {

      Diags.Report(Pos.getLocWithOffset(PH.C - PH.Begin),

                   diag::err_verify_missing_end)

          << KindStr << CloseBrace;

      continue;

    }

    const char* const ContentEnd = PH.P; // mark content end

    PH.Advance();

    D.DirectivePos = Pos;

    D.ContentBegin = Pos.getLocWithOffset(ContentBegin - PH.Begin);

    // Build directive text; convert \n to newlines.

    StringRef NewlineStr = "\\n";

    StringRef Content(ContentBegin, ContentEnd-ContentBegin);

    size_t CPos = 0;

    size_t FPos;

    while ((FPos = Content.find(NewlineStr, CPos)) != StringRef::npos) {

      D.Text += Content.substr(CPos, FPos-CPos);

      D.Text += '\n';

      CPos = FPos + NewlineStr.size();

    }

    if (D.Text.empty())

      D.Text.assign(ContentBegin, ContentEnd);

    // Check that regex directives contain at least one regex.

    if (D.RegexKind && D.Text.find("{{") == StringRef::npos) {

      Diags.Report(D.ContentBegin, diag::err_verify_missing_regex) << D.Text;

      return false;

    }

    if (Marker.empty())

      attachDirective(Diags, D, ExpectedLoc, MatchAnyFileAndLine, MatchAnyLine);

    else

      Markers.addDirective(Marker, D);

    FoundDirective = true;

  }

  return FoundDirective;

}

VerifyDiagnosticConsumer::VerifyDiagnosticConsumer(DiagnosticsEngine &Diags_)

    : Diags(Diags_), PrimaryClient(Diags.getClient()),

      PrimaryClientOwner(Diags.takeClient()),

      Buffer(new TextDiagnosticBuffer()), Markers(new MarkerTracker(Diags)),

      Status(HasNoDirectives) {

  if (Diags.hasSourceManager())

    setSourceManager(Diags.getSourceManager());

}

VerifyDiagnosticConsumer::~VerifyDiagnosticConsumer() {

  assert(!ActiveSourceFiles && "Incomplete parsing of source files!");

  assert(!CurrentPreprocessor && "CurrentPreprocessor should be invalid!");

  SrcManager = nullptr;

  CheckDiagnostics();

  assert(!Diags.ownsClient() &&

         "The VerifyDiagnosticConsumer takes over ownership of the client!");

}

// DiagnosticConsumer interface.

void VerifyDiagnosticConsumer::BeginSourceFile(const LangOptions &LangOpts,

                                               const Preprocessor *PP) {

  // Attach comment handler on first invocation.

  if (++ActiveSourceFiles == 1) {

    if (PP) {

      CurrentPreprocessor = PP;

      this->LangOpts = &LangOpts;

      setSourceManager(PP->getSourceManager());

      const_cast<Preprocessor *>(PP)->addCommentHandler(this);

#ifndef NDEBUG

      // Debug build tracks parsed files.

      const_cast<Preprocessor *>(PP)->addPPCallbacks(

                      std::make_unique<VerifyFileTracker>(*this, *SrcManager));

#endif

    }

  }

  assert((!PP || CurrentPreprocessor == PP) && "Preprocessor changed!");

  PrimaryClient->BeginSourceFile(LangOpts, PP);

}

void VerifyDiagnosticConsumer::EndSourceFile() {

  assert(ActiveSourceFiles && "No active source files!");

  PrimaryClient->EndSourceFile();

  // Detach comment handler once last active source file completed.

  if (--ActiveSourceFiles == 0) {

    if (CurrentPreprocessor)

      const_cast<Preprocessor *>(CurrentPreprocessor)->

          removeCommentHandler(this);

    // Diagnose any used-but-not-defined markers.

    Markers->finalize();

    // Check diagnostics once last file completed.

    CheckDiagnostics();

    CurrentPreprocessor = nullptr;

    LangOpts = nullptr;

  }

}

void VerifyDiagnosticConsumer::HandleDiagnostic(

      DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info) {

  if (Info.hasSourceManager()) {

    // If this diagnostic is for a different source manager, ignore it.

    if (SrcManager && &Info.getSourceManager() != SrcManager)

      return;

    setSourceManager(Info.getSourceManager());

  }

#ifndef NDEBUG

  // Debug build tracks unparsed files for possible

  // unparsed expected-* directives.

  if (SrcManager) {

    SourceLocation Loc = Info.getLocation();

    if (Loc.isValid()) {

      ParsedStatus PS = IsUnparsed;

      Loc = SrcManager->getExpansionLoc(Loc);

      FileID FID = SrcManager->getFileID(Loc);

      auto FE = SrcManager->getFileEntryRefForID(FID);

      if (FE && CurrentPreprocessor && SrcManager->isLoadedFileID(FID)) {

        // If the file is a modules header file it shall not be parsed

        // for expected-* directives.

        HeaderSearch &HS = CurrentPreprocessor->getHeaderSearchInfo();

        if (HS.findModuleForHeader(*FE))

          PS = IsUnparsedNoDirectives;

      }

      UpdateParsedFileStatus(*SrcManager, FID, PS);

    }

  }

#endif

  // Send the diagnostic to the buffer, we will check it once we reach the end

  // of the source file (or are destructed).

  Buffer->HandleDiagnostic(DiagLevel, Info);

}

/// HandleComment - Hook into the preprocessor and extract comments containing

///  expected errors and warnings.

bool VerifyDiagnosticConsumer::HandleComment(Preprocessor &PP,

                                             SourceRange Comment) {

  SourceManager &SM = PP.getSourceManager();

  // If this comment is for a different source manager, ignore it.

  if (SrcManager && &SM != SrcManager)

    return false;

  SourceLocation CommentBegin = Comment.getBegin();

  const char *CommentRaw = SM.getCharacterData(CommentBegin);

  StringRef C(CommentRaw, SM.getCharacterData(Comment.getEnd()) - CommentRaw);

  if (C.empty())

    return false;

  // Fold any "\<EOL>" sequences

  size_t loc = C.find('\\');

  if (loc == StringRef::npos) {

    ParseDirective(C, &ED, SM, &PP, CommentBegin, Status, *Markers);

    return false;

  }

  std::string C2;

  C2.reserve(C.size());

  for (size_t last = 0;; loc = C.find('\\', last)) {

    if (loc == StringRef::npos || loc == C.size()) {

      C2 += C.substr(last);

      break;

    }

    C2 += C.substr(last, loc-last);

    last = loc + 1;

    if (C[last] == '\n' || C[last] == '\r') {

      ++last;

      // Escape \r\n  or \n\r, but not \n\n.

      if (last < C.size())

        if (C[last] == '\n' || C[last] == '\r')

          if (C[last] != C[last-1])

            ++last;

    } else {

      // This was just a normal backslash.

      C2 += '\\';

    }

  }

  if (!C2.empty())

    ParseDirective(C2, &ED, SM, &PP, CommentBegin, Status, *Markers);

  return false;

}

#ifndef NDEBUG

/// Lex the specified source file to determine whether it contains

/// any expected-* directives.  As a Lexer is used rather than a full-blown

/// Preprocessor, directives inside skipped #if blocks will still be found.

///

/// \return true if any directives were found.

static bool findDirectives(SourceManager &SM, FileID FID,

                           const LangOptions &LangOpts) {

  // Create a raw lexer to pull all the comments out of FID.

  if (FID.isInvalid())

    return false;

  // Create a lexer to lex all the tokens of the main file in raw mode.

  llvm::MemoryBufferRef FromFile = SM.getBufferOrFake(FID);

  Lexer RawLex(FID, FromFile, SM, LangOpts);

  // Return comments as tokens, this is how we find expected diagnostics.

  RawLex.SetCommentRetentionState(true);

  Token Tok;

  Tok.setKind(tok::comment);

  VerifyDiagnosticConsumer::DirectiveStatus Status =

    VerifyDiagnosticConsumer::HasNoDirectives;

  while (Tok.isNot(tok::eof)) {

    RawLex.LexFromRawLexer(Tok);

    if (!Tok.is(tok::comment)) continue;

    std::string Comment = RawLex.getSpelling(Tok, SM, LangOpts);

    if (Comment.empty()) continue;

    // We don't care about tracking markers for this phase.

    VerifyDiagnosticConsumer::MarkerTracker Markers(SM.getDiagnostics());

    // Find first directive.

    if (ParseDirective(Comment, nullptr, SM, nullptr, Tok.getLocation(),

                       Status, Markers))

      return true;

  }

  return false;

}

#endif // !NDEBUG

/// Takes a list of diagnostics that have been generated but not matched

/// by an expected-* directive and produces a diagnostic to the user from this.

static unsigned PrintUnexpected(DiagnosticsEngine &Diags, SourceManager *SourceMgr,

                                const_diag_iterator diag_begin,

                                const_diag_iterator diag_end,

                                const char *Kind) {

  if (diag_begin == diag_end) return 0;

  SmallString<256> Fmt;

  llvm::raw_svector_ostream OS(Fmt);

  for (const_diag_iterator I = diag_begin, E = diag_end; I != E; ++I) {

    if (I->first.isInvalid() || !SourceMgr)

      OS << "\n  (frontend)";

    else {

      OS << "\n ";

      if (OptionalFileEntryRef File =

              SourceMgr->getFileEntryRefForID(SourceMgr->getFileID(I->first)))

        OS << " File " << File->getName();

      OS << " Line " << SourceMgr->getPresumedLineNumber(I->first);

    }

    OS << ": " << I->second;

  }

  std::string Prefix = *Diags.getDiagnosticOptions().VerifyPrefixes.begin();

  std::string KindStr = Prefix + "-" + Kind;

  Diags.Report(diag::err_verify_inconsistent_diags).setForceEmit()

      << KindStr << /*Unexpected=*/true << OS.str();

  return std::distance(diag_begin, diag_end);

}

/// Takes a list of diagnostics that were expected to have been generated

/// but were not and produces a diagnostic to the user from this.

static unsigned PrintExpected(DiagnosticsEngine &Diags,

                              SourceManager &SourceMgr,

                              std::vector<Directive *> &DL, const char *Kind) {

  if (DL.empty())

    return 0;

  SmallString<256> Fmt;

  llvm::raw_svector_ostream OS(Fmt);

  for (const auto *D : DL) {

    if (D->DiagnosticLoc.isInvalid() || D->MatchAnyFileAndLine)