[clang-tidy] Fix treating non-space whitespaces in checks list.

[curdeius]

Summary

This furtherly improves r295303: [clang-tidy] Ignore spaces between globs in the Checks option.
Trims all whitespaces and not only spaces and correctly computes the offset of the checks list (taking the size before trimming).

[alexfh]

What's the practical use of newlines and tab characters in the glob list?

[curdeius]

Hi Alex and sorry for the late reply.

The main use case is a more readable .clang-tidy configuration checks.
Before this correction one can use something like this:

---
Checks: '
    ,*,
    ,-cert-dcl03-c,
'
...

It works, but is hardly comprehensible to a newbie (the strange use of addtional commas).
Since the spaces are ignored (since a recent commit of yours) we can add spaces after the leading comma and hope that no user uses a tab...

After applying this patch, we can just write (with tabs or spaces and as many newlines as we want - used for grouping for instance):

---
Checks: '
    *,
    -cert-dcl03-c,
'
...

Additionaly, you can sometimes accidentally issue a tabulator on the command line and that's just nice to ignore it.

[alexfh]

In D30567#696436, @curdeius wrote:

Hi Alex and sorry for the late reply.

The main use case is a more readable .clang-tidy configuration checks.
Before this correction one can use something like this:

---
Checks: '
    ,*,
    ,-cert-dcl03-c,
'
...

It works, but is hardly comprehensible to a newbie (the strange use of addtional commas).
Since the spaces are ignored (since a recent commit of yours) we can add spaces after the leading comma and hope that no user uses a tab...

After applying this patch, we can just write (with tabs or spaces and as many newlines as we want - used for grouping for instance):

---
Checks: '
    *,
    -cert-dcl03-c,
'
...

Additionaly, you can sometimes accidentally issue a tabulator on the command line and that's just nice to ignore it.

Currently, one can use YAML folded strings to split the list of checks to multiple lines:

Checks: >
  -*,
  cert-dcl03-c

So it's not necessary to trim newlines. And tabs are forbidden in YAML: http://www.yaml.org/faq.html. So I'd suggest to leave .trim(' '). The rest of the change looks good - thanks for catching the bug ;)

[curdeius]

Trim only spaces.

[curdeius]

Hi Alex, is it OK now?

[alexfh]

There's one more trim() you missed. And the test needs to be updated (s/\\n/ /).

clang-tidy/ClangTidyDiagnosticConsumer.cpp

133

s/trim()/trim(' ')/

[curdeius]

Trim spaces only everywhere. Fix test.

[alexfh]

LG. Thanks!

Do you have commit rights?

[curdeius]

In D30567#708797, @alexfh wrote:

Do you have commit rights?

Yes, I will commit this ASAP.

clang-tidy/ClangTidyDiagnosticConsumer.cpp

-//===--- tools/extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp ----------=== //
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-///  \file This file implements ClangTidyDiagnosticConsumer, ClangTidyContext
-///  and ClangTidyError classes.
-///
-///  This tool uses the Clang Tooling infrastructure, see
-///    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
-///  for details on setting it up with LLVM source tree.
-///
-//===----------------------------------------------------------------------===//
-
-#include "ClangTidyDiagnosticConsumer.h"
-#include "ClangTidyOptions.h"
-#include "clang/AST/ASTDiagnostic.h"
-#include "clang/Basic/DiagnosticOptions.h"
-#include "clang/Frontend/DiagnosticRenderer.h"
-#include "llvm/ADT/SmallString.h"
-#include <tuple>
-#include <vector>
-using namespace clang;
-using namespace tidy;
-
-namespace {
-class ClangTidyDiagnosticRenderer : public DiagnosticRenderer {
-public:
-  ClangTidyDiagnosticRenderer(const LangOptions &LangOpts,
-                              DiagnosticOptions *DiagOpts,
-                              ClangTidyError &Error)
-      : DiagnosticRenderer(LangOpts, DiagOpts), Error(Error) {}
-
-protected:
-  void emitDiagnosticMessage(SourceLocation Loc, PresumedLoc PLoc,
-                             DiagnosticsEngine::Level Level, StringRef Message,
-                             ArrayRef<CharSourceRange> Ranges,
-                             const SourceManager *SM,
-                             DiagOrStoredDiag Info) override {
-    // Remove check name from the message.
-    // FIXME: Remove this once there's a better way to pass check names than
-    // appending the check name to the message in ClangTidyContext::diag and
-    // using getCustomDiagID.
-    std::string CheckNameInMessage = " [" + Error.DiagnosticName + "]";
-    if (Message.endswith(CheckNameInMessage))
-      Message = Message.substr(0, Message.size() - CheckNameInMessage.size());
-
-    auto TidyMessage = Loc.isValid()
-                           ? tooling::DiagnosticMessage(Message, *SM, Loc)
-                           : tooling::DiagnosticMessage(Message);
-    if (Level == DiagnosticsEngine::Note) {
-      Error.Notes.push_back(TidyMessage);
-      return;
-    }
-    assert(Error.Message.Message.empty() && "Overwriting a diagnostic message");
-    Error.Message = TidyMessage;
-  }
-
-  void emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
-                         DiagnosticsEngine::Level Level,
-                         ArrayRef<CharSourceRange> Ranges,
-                         const SourceManager &SM) override {}
-
-  void emitCodeContext(SourceLocation Loc, DiagnosticsEngine::Level Level,
-                       SmallVectorImpl<CharSourceRange> &Ranges,
-                       ArrayRef<FixItHint> Hints,
-                       const SourceManager &SM) override {
-    assert(Loc.isValid());
-    for (const auto &FixIt : Hints) {
-      CharSourceRange Range = FixIt.RemoveRange;
-      assert(Range.getBegin().isValid() && Range.getEnd().isValid() &&
-             "Invalid range in the fix-it hint.");
-      assert(Range.getBegin().isFileID() && Range.getEnd().isFileID() &&
-             "Only file locations supported in fix-it hints.");
-
-      tooling::Replacement Replacement(SM, Range, FixIt.CodeToInsert);
-      llvm::Error Err = Error.Fix[Replacement.getFilePath()].add(Replacement);
-      // FIXME: better error handling (at least, don't let other replacements be
-      // applied).
-      if (Err) {
-        llvm::errs() << "Fix conflicts with existing fix! "
-                     << llvm::toString(std::move(Err)) << "\n";
-        assert(false && "Fix conflicts with existing fix!");
-      }
-    }
-  }
-
-  void emitIncludeLocation(SourceLocation Loc, PresumedLoc PLoc,
-                           const SourceManager &SM) override {}
-
-  void emitImportLocation(SourceLocation Loc, PresumedLoc PLoc,
-                          StringRef ModuleName,
-                          const SourceManager &SM) override {}
-
-  void emitBuildingModuleLocation(SourceLocation Loc, PresumedLoc PLoc,
-                                  StringRef ModuleName,
-                                  const SourceManager &SM) override {}
-
-  void endDiagnostic(DiagOrStoredDiag D,
-                     DiagnosticsEngine::Level Level) override {
-    assert(!Error.Message.Message.empty() && "Message has not been set");
-  }
-
-private:
-  ClangTidyError &Error;
-};
-} // end anonymous namespace
-
-ClangTidyError::ClangTidyError(StringRef CheckName,
-                               ClangTidyError::Level DiagLevel,
-                               StringRef BuildDirectory, bool IsWarningAsError)
-    : tooling::Diagnostic(CheckName, DiagLevel, BuildDirectory),
-      IsWarningAsError(IsWarningAsError) {}
-
-// Returns true if GlobList starts with the negative indicator ('-'), removes it
-// from the GlobList.
-static bool ConsumeNegativeIndicator(StringRef &GlobList) {
-  GlobList = GlobList.trim(' ');
-  if (GlobList.startswith("-")) {
-    GlobList = GlobList.substr(1);
-    return true;
-  }
-  return false;
-}
-// Converts first glob from the comma-separated list of globs to Regex and
-// removes it and the trailing comma from the GlobList.
-static llvm::Regex ConsumeGlob(StringRef &GlobList) {
-  StringRef Glob = GlobList.substr(0, GlobList.find(',')).trim();
-  GlobList = GlobList.substr(Glob.size() + 1);
-  SmallString<128> RegexText("^");
-  StringRef MetaChars("()^$|*+?.[]\\{}");
-  for (char C : Glob) {
-    if (C == '*')
-      RegexText.push_back('.');
-    else if (MetaChars.find(C) != StringRef::npos)
-      RegexText.push_back('\\');
-    RegexText.push_back(C);
-  }
-  RegexText.push_back('$');
-  return llvm::Regex(RegexText);
-}
-
-GlobList::GlobList(StringRef Globs)
-    : Positive(!ConsumeNegativeIndicator(Globs)), Regex(ConsumeGlob(Globs)),
-      NextGlob(Globs.empty() ? nullptr : new GlobList(Globs)) {}
-
-bool GlobList::contains(StringRef S, bool Contains) {
-  if (Regex.match(S))
-    Contains = Positive;
-
-  if (NextGlob)
-    Contains = NextGlob->contains(S, Contains);
-  return Contains;
-}
-
-ClangTidyContext::ClangTidyContext(
-    std::unique_ptr<ClangTidyOptionsProvider> OptionsProvider)
-    : DiagEngine(nullptr), OptionsProvider(std::move(OptionsProvider)),
-      Profile(nullptr) {
-  // Before the first translation unit we can get errors related to command-line
-  // parsing, use empty string for the file name in this case.
-  setCurrentFile("");
-}
-
-DiagnosticBuilder ClangTidyContext::diag(
-    StringRef CheckName, SourceLocation Loc, StringRef Description,
-    DiagnosticIDs::Level Level /* = DiagnosticIDs::Warning*/) {
-  assert(Loc.isValid());
-  unsigned ID = DiagEngine->getDiagnosticIDs()->getCustomDiagID(
-      Level, (Description + " [" + CheckName + "]").str());
-  CheckNamesByDiagnosticID.try_emplace(ID, CheckName);
-  return DiagEngine->Report(Loc, ID);
-}
-
-void ClangTidyContext::setDiagnosticsEngine(DiagnosticsEngine *Engine) {
-  DiagEngine = Engine;
-}
-
-void ClangTidyContext::setSourceManager(SourceManager *SourceMgr) {
-  DiagEngine->setSourceManager(SourceMgr);
-}
-
-void ClangTidyContext::setCurrentFile(StringRef File) {
-  CurrentFile = File;
-  CurrentOptions = getOptionsForFile(CurrentFile);
-  CheckFilter.reset(new GlobList(*getOptions().Checks));
-  WarningAsErrorFilter.reset(new GlobList(*getOptions().WarningsAsErrors));
-}
-
-void ClangTidyContext::setASTContext(ASTContext *Context) {
-  DiagEngine->SetArgToStringFn(&FormatASTNodeDiagnosticArgument, Context);
-  LangOpts = Context->getLangOpts();
-}
-
-const ClangTidyGlobalOptions &ClangTidyContext::getGlobalOptions() const {
-  return OptionsProvider->getGlobalOptions();
-}
-
-const ClangTidyOptions &ClangTidyContext::getOptions() const {
-  return CurrentOptions;
-}
-
-ClangTidyOptions ClangTidyContext::getOptionsForFile(StringRef File) const {
-  // Merge options on top of getDefaults() as a safeguard against options with
-  // unset values.
-  return ClangTidyOptions::getDefaults().mergeWith(
-      OptionsProvider->getOptions(File));
-}
-
-void ClangTidyContext::setCheckProfileData(ProfileData *P) { Profile = P; }
-
-GlobList &ClangTidyContext::getChecksFilter() {
-  assert(CheckFilter != nullptr);
-  return *CheckFilter;
-}
-
-GlobList &ClangTidyContext::getWarningAsErrorFilter() {
-  assert(WarningAsErrorFilter != nullptr);
-  return *WarningAsErrorFilter;
-}
-
-/// \brief Store a \c ClangTidyError.
-void ClangTidyContext::storeError(const ClangTidyError &Error) {
-  Errors.push_back(Error);
-}
-
-StringRef ClangTidyContext::getCheckName(unsigned DiagnosticID) const {
-  llvm::DenseMap<unsigned, std::string>::const_iterator I =
-      CheckNamesByDiagnosticID.find(DiagnosticID);
-  if (I != CheckNamesByDiagnosticID.end())
-    return I->second;
-  return "";
-}
-
-ClangTidyDiagnosticConsumer::ClangTidyDiagnosticConsumer(ClangTidyContext &Ctx)
-    : Context(Ctx), LastErrorRelatesToUserCode(false),
-      LastErrorPassesLineFilter(false), LastErrorWasIgnored(false) {
-  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
-  Diags.reset(new DiagnosticsEngine(
-      IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs), &*DiagOpts, this,
-      /*ShouldOwnClient=*/false));
-  Context.setDiagnosticsEngine(Diags.get());
-}
-
-void ClangTidyDiagnosticConsumer::finalizeLastError() {
-  if (!Errors.empty()) {
-    ClangTidyError &Error = Errors.back();
-    if (!Context.getChecksFilter().contains(Error.DiagnosticName) &&
-        Error.DiagLevel != ClangTidyError::Error) {
-      ++Context.Stats.ErrorsIgnoredCheckFilter;
-      Errors.pop_back();
-    } else if (!LastErrorRelatesToUserCode) {
-      ++Context.Stats.ErrorsIgnoredNonUserCode;
-      Errors.pop_back();
-    } else if (!LastErrorPassesLineFilter) {
-      ++Context.Stats.ErrorsIgnoredLineFilter;
-      Errors.pop_back();
-    } else {
-      ++Context.Stats.ErrorsDisplayed;
-    }
-  }
-  LastErrorRelatesToUserCode = false;
-  LastErrorPassesLineFilter = false;
-}
-
-static bool LineIsMarkedWithNOLINT(SourceManager &SM, SourceLocation Loc) {
-  bool Invalid;
-  const char *CharacterData = SM.getCharacterData(Loc, &Invalid);
-  if (Invalid)
-    return false;
-
-  // Check if there's a NOLINT on this line.
-  const char *P = CharacterData;
-  while (*P != '\0' && *P != '\r' && *P != '\n')
-    ++P;
-  StringRef RestOfLine(CharacterData, P - CharacterData + 1);
-  // FIXME: Handle /\bNOLINT\b(\([^)]*\))?/ as cpplint.py does.
-  if (RestOfLine.find("NOLINT") != StringRef::npos)
-    return true;
-
-  // Check if there's a NOLINTNEXTLINE on the previous line.
-  const char *BufBegin =
-      SM.getCharacterData(SM.getLocForStartOfFile(SM.getFileID(Loc)), &Invalid);
-  if (Invalid || P == BufBegin)
-    return false;
-
-  // Scan backwards over the current line.
-  P = CharacterData;
-  while (P != BufBegin && *P != '\n')
-    --P;
-
-  // If we reached the begin of the file there is no line before it.
-  if (P == BufBegin)
-    return false;
-
-  // Skip over the newline.
-  --P;
-  const char *LineEnd = P;
-
-  // Now we're on the previous line. Skip to the beginning of it.
-  while (P != BufBegin && *P != '\n')
-    --P;
-
-  RestOfLine = StringRef(P, LineEnd - P + 1);
-  if (RestOfLine.find("NOLINTNEXTLINE") != StringRef::npos)
-    return true;
-
-  return false;
-}
-
-static bool LineIsMarkedWithNOLINTinMacro(SourceManager &SM,
-                                          SourceLocation Loc) {
-  while (true) {
-    if (LineIsMarkedWithNOLINT(SM, Loc))
-      return true;
-    if (!Loc.isMacroID())
-      return false;
-    Loc = SM.getImmediateExpansionRange(Loc).first;
-  }
-  return false;
-}
-
-void ClangTidyDiagnosticConsumer::HandleDiagnostic(
-    DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info) {
-  if (LastErrorWasIgnored && DiagLevel == DiagnosticsEngine::Note)
-    return;
-
-  if (Info.getLocation().isValid() && DiagLevel != DiagnosticsEngine::Error &&
-      DiagLevel != DiagnosticsEngine::Fatal &&
-      LineIsMarkedWithNOLINTinMacro(Diags->getSourceManager(),
-                                    Info.getLocation())) {
-    ++Context.Stats.ErrorsIgnoredNOLINT;
-    // Ignored a warning, should ignore related notes as well
-    LastErrorWasIgnored = true;
-    return;
-  }
-
-  LastErrorWasIgnored = false;
-  // Count warnings/errors.
-  DiagnosticConsumer::HandleDiagnostic(DiagLevel, Info);
-
-  if (DiagLevel == DiagnosticsEngine::Note) {
-    assert(!Errors.empty() &&
-           "A diagnostic note can only be appended to a message.");
-  } else {
-    finalizeLastError();
-    StringRef WarningOption =
-        Context.DiagEngine->getDiagnosticIDs()->getWarningOptionForDiag(
-            Info.getID());
-    std::string CheckName = !WarningOption.empty()
-                                ? ("clang-diagnostic-" + WarningOption).str()
-                                : Context.getCheckName(Info.getID()).str();
-
-    if (CheckName.empty()) {
-      // This is a compiler diagnostic without a warning option. Assign check
-      // name based on its level.
-      switch (DiagLevel) {
-      case DiagnosticsEngine::Error:
-      case DiagnosticsEngine::Fatal:
-        CheckName = "clang-diagnostic-error";
-        break;
-      case DiagnosticsEngine::Warning:
-        CheckName = "clang-diagnostic-warning";
-        break;
-      default:
-        CheckName = "clang-diagnostic-unknown";
-        break;
-      }
-    }
-
-    ClangTidyError::Level Level = ClangTidyError::Warning;
-    if (DiagLevel == DiagnosticsEngine::Error ||
-        DiagLevel == DiagnosticsEngine::Fatal) {
-      // Force reporting of Clang errors regardless of filters and non-user
-      // code.
-      Level = ClangTidyError::Error;
-      LastErrorRelatesToUserCode = true;
-      LastErrorPassesLineFilter = true;
-    }
-    bool IsWarningAsError =
-        DiagLevel == DiagnosticsEngine::Warning &&
-        Context.getWarningAsErrorFilter().contains(CheckName);
-    Errors.emplace_back(CheckName, Level, Context.getCurrentBuildDirectory(),
-                        IsWarningAsError);
-  }
-
-  ClangTidyDiagnosticRenderer Converter(
-      Context.getLangOpts(), &Context.DiagEngine->getDiagnosticOptions(),
-      Errors.back());
-  SmallString<100> Message;
-  Info.FormatDiagnostic(Message);
-  SourceManager *Sources = nullptr;
-  if (Info.hasSourceManager())
-    Sources = &Info.getSourceManager();
-  Converter.emitDiagnostic(Info.getLocation(), DiagLevel, Message,
-                           Info.getRanges(), Info.getFixItHints(), Sources);
-
-  checkFilters(Info.getLocation());
-}
-
-bool ClangTidyDiagnosticConsumer::passesLineFilter(StringRef FileName,
-                                                   unsigned LineNumber) const {
-  if (Context.getGlobalOptions().LineFilter.empty())
-    return true;
-  for (const FileFilter &Filter : Context.getGlobalOptions().LineFilter) {
-    if (FileName.endswith(Filter.Name)) {
-      if (Filter.LineRanges.empty())
-        return true;
-      for (const FileFilter::LineRange &Range : Filter.LineRanges) {
-        if (Range.first <= LineNumber && LineNumber <= Range.second)
-          return true;
-      }
-      return false;
-    }
-  }
-  return false;
-}
-
-void ClangTidyDiagnosticConsumer::checkFilters(SourceLocation Location) {
-  // Invalid location may mean a diagnostic in a command line, don't skip these.
-  if (!Location.isValid()) {
-    LastErrorRelatesToUserCode = true;
-    LastErrorPassesLineFilter = true;
-    return;
-  }
-
-  const SourceManager &Sources = Diags->getSourceManager();
-  if (!*Context.getOptions().SystemHeaders &&
-      Sources.isInSystemHeader(Location))
-    return;
-
-  // FIXME: We start with a conservative approach here, but the actual type of
-  // location needed depends on the check (in particular, where this check wants
-  // to apply fixes).
-  FileID FID = Sources.getDecomposedExpansionLoc(Location).first;
-  const FileEntry *File = Sources.getFileEntryForID(FID);
-
-  // -DMACRO definitions on the command line have locations in a virtual buffer
-  // that doesn't have a FileEntry. Don't skip these as well.
-  if (!File) {
-    LastErrorRelatesToUserCode = true;
-    LastErrorPassesLineFilter = true;
-    return;
-  }
-
-  StringRef FileName(File->getName());
-  LastErrorRelatesToUserCode = LastErrorRelatesToUserCode ||
-                               Sources.isInMainFile(Location) ||
-                               getHeaderFilter()->match(FileName);
-
-  unsigned LineNumber = Sources.getExpansionLineNumber(Location);
-  LastErrorPassesLineFilter =
-      LastErrorPassesLineFilter || passesLineFilter(FileName, LineNumber);
-}
-
-llvm::Regex *ClangTidyDiagnosticConsumer::getHeaderFilter() {
-  if (!HeaderFilter)
-    HeaderFilter.reset(
-        new llvm::Regex(*Context.getOptions().HeaderFilterRegex));
-  return HeaderFilter.get();
-}
-
-void ClangTidyDiagnosticConsumer::removeIncompatibleErrors(
-    SmallVectorImpl<ClangTidyError> &Errors) const {
-  // Each error is modelled as the set of intervals in which it applies
-  // replacements. To detect overlapping replacements, we use a sweep line
-  // algorithm over these sets of intervals.
-  // An event here consists of the opening or closing of an interval. During the
-  // process, we maintain a counter with the amount of open intervals. If we
-  // find an endpoint of an interval and this counter is different from 0, it
-  // means that this interval overlaps with another one, so we set it as
-  // inapplicable.
-  struct Event {
-    // An event can be either the begin or the end of an interval.
-    enum EventType {
-      ET_Begin = 1,
-      ET_End = -1,
-    };
-
-    Event(unsigned Begin, unsigned End, EventType Type, unsigned ErrorId,
-          unsigned ErrorSize)
-        : Type(Type), ErrorId(ErrorId) {
-      // The events are going to be sorted by their position. In case of draw:
-      //
-      // * If an interval ends at the same position at which other interval
-      //   begins, this is not an overlapping, so we want to remove the ending
-      //   interval before adding the starting one: end events have higher
-      //   priority than begin events.
-      //
-      // * If we have several begin points at the same position, we will mark as
-      //   inapplicable the ones that we process later, so the first one has to
-      //   be the one with the latest end point, because this one will contain
-      //   all the other intervals. For the same reason, if we have several end
-      //   points in the same position, the last one has to be the one with the
-      //   earliest begin point. In both cases, we sort non-increasingly by the
-      //   position of the complementary.
-      //
-      // * In case of two equal intervals, the one whose error is bigger can
-      //   potentially contain the other one, so we want to process its begin
-      //   points before and its end points later.
-      //
-      // * Finally, if we have two equal intervals whose errors have the same
-      //   size, none of them will be strictly contained inside the other.
-      //   Sorting by ErrorId will guarantee that the begin point of the first
-      //   one will be processed before, disallowing the second one, and the
-      //   end point of the first one will also be processed before,
-      //   disallowing the first one.
-      if (Type == ET_Begin)
-        Priority = std::make_tuple(Begin, Type, -End, -ErrorSize, ErrorId);
-      else
-        Priority = std::make_tuple(End, Type, -Begin, ErrorSize, ErrorId);
-    }
-
-    bool operator<(const Event &Other) const {
-      return Priority < Other.Priority;
-    }
-
-    // Determines if this event is the begin or the end of an interval.
-    EventType Type;
-    // The index of the error to which the interval that generated this event
-    // belongs.
-    unsigned ErrorId;
-    // The events will be sorted based on this field.
-    std::tuple<unsigned, EventType, int, int, unsigned> Priority;
-  };
-
-  // Compute error sizes.
-  std::vector<int> Sizes;
-  for (const auto &Error : Errors) {
-    int Size = 0;
-    for (const auto &FileAndReplaces : Error.Fix) {
-      for (const auto &Replace : FileAndReplaces.second)
-        Size += Replace.getLength();
-    }
-    Sizes.push_back(Size);
-  }
-
-  // Build events from error intervals.
-  std::map<std::string, std::vector<Event>> FileEvents;
-  for (unsigned I = 0; I < Errors.size(); ++I) {
-    for (const auto &FileAndReplace : Errors[I].Fix) {
-      for (const auto &Replace : FileAndReplace.second) {
-        unsigned Begin = Replace.getOffset();
-        unsigned End = Begin + Replace.getLength();
-        const std::string &FilePath = Replace.getFilePath();
-        // FIXME: Handle empty intervals, such as those from insertions.
-        if (Begin == End)
-          continue;
-        auto &Events = FileEvents[FilePath];
-        Events.emplace_back(Begin, End, Event::ET_Begin, I, Sizes[I]);
-        Events.emplace_back(Begin, End, Event::ET_End, I, Sizes[I]);
-      }
-    }
-  }
-
-  std::vector<bool> Apply(Errors.size(), true);
-  for (auto &FileAndEvents : FileEvents) {
-    std::vector<Event> &Events = FileAndEvents.second;
-    // Sweep.
-    std::sort(Events.begin(), Events.end());
-    int OpenIntervals = 0;
-    for (const auto &Event : Events) {
-      if (Event.Type == Event::ET_End)
-        --OpenIntervals;
-      // This has to be checked after removing the interval from the count if it
-      // is an end event, or before adding it if it is a begin event.
-      if (OpenIntervals != 0)
-        Apply[Event.ErrorId] = false;
-      if (Event.Type == Event::ET_Begin)
-        ++OpenIntervals;
-    }
-    assert(OpenIntervals == 0 && "Amount of begin/end points doesn't match");
-  }
-
-  for (unsigned I = 0; I < Errors.size(); ++I) {
-    if (!Apply[I]) {
-      Errors[I].Fix.clear();
-      Errors[I].Notes.emplace_back(
-          "this fix will not be applied because it overlaps with another fix");
-    }
-  }
-}
-
-namespace {
-struct LessClangTidyError {
-  bool operator()(const ClangTidyError &LHS, const ClangTidyError &RHS) const {
-    const tooling::DiagnosticMessage &M1 = LHS.Message;
-    const tooling::DiagnosticMessage &M2 = RHS.Message;
-
-    return std::tie(M1.FilePath, M1.FileOffset, M1.Message) <
-           std::tie(M2.FilePath, M2.FileOffset, M2.Message);
-  }
-};
-struct EqualClangTidyError {
-  bool operator()(const ClangTidyError &LHS, const ClangTidyError &RHS) const {
-    LessClangTidyError Less;
-    return !Less(LHS, RHS) && !Less(RHS, LHS);
-  }
-};
-} // end anonymous namespace
-
-// Flushes the internal diagnostics buffer to the ClangTidyContext.
-void ClangTidyDiagnosticConsumer::finish() {
-  finalizeLastError();
-
-  std::sort(Errors.begin(), Errors.end(), LessClangTidyError());
-  Errors.erase(std::unique(Errors.begin(), Errors.end(), EqualClangTidyError()),
-               Errors.end());
-  removeIncompatibleErrors(Errors);
-
-  for (const ClangTidyError &Error : Errors)
-    Context.storeError(Error);
-  Errors.clear();
-}
+//===--- tools/extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp ----------=== //
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+///  \file This file implements ClangTidyDiagnosticConsumer, ClangTidyContext
+///  and ClangTidyError classes.
+///
+///  This tool uses the Clang Tooling infrastructure, see
+///    http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
+///  for details on setting it up with LLVM source tree.
+///
+//===----------------------------------------------------------------------===//
+
+#include "ClangTidyDiagnosticConsumer.h"
+#include "ClangTidyOptions.h"
+#include "clang/AST/ASTDiagnostic.h"
+#include "clang/Basic/DiagnosticOptions.h"
+#include "clang/Frontend/DiagnosticRenderer.h"
+#include "llvm/ADT/SmallString.h"
+#include <tuple>
+#include <vector>
+using namespace clang;
+using namespace tidy;
+
+namespace {
+class ClangTidyDiagnosticRenderer : public DiagnosticRenderer {
+public:
+  ClangTidyDiagnosticRenderer(const LangOptions &LangOpts,
+                              DiagnosticOptions *DiagOpts,
+                              ClangTidyError &Error)
+      : DiagnosticRenderer(LangOpts, DiagOpts), Error(Error) {}
+
+protected:
+  void emitDiagnosticMessage(SourceLocation Loc, PresumedLoc PLoc,
+                             DiagnosticsEngine::Level Level, StringRef Message,
+                             ArrayRef<CharSourceRange> Ranges,
+                             const SourceManager *SM,
+                             DiagOrStoredDiag Info) override {
+    // Remove check name from the message.
+    // FIXME: Remove this once there's a better way to pass check names than
+    // appending the check name to the message in ClangTidyContext::diag and
+    // using getCustomDiagID.
+    std::string CheckNameInMessage = " [" + Error.DiagnosticName + "]";
+    if (Message.endswith(CheckNameInMessage))
+      Message = Message.substr(0, Message.size() - CheckNameInMessage.size());
+
+    auto TidyMessage = Loc.isValid()
+                           ? tooling::DiagnosticMessage(Message, *SM, Loc)
+                           : tooling::DiagnosticMessage(Message);
+    if (Level == DiagnosticsEngine::Note) {
+      Error.Notes.push_back(TidyMessage);
+      return;
+    }
+    assert(Error.Message.Message.empty() && "Overwriting a diagnostic message");
+    Error.Message = TidyMessage;
+  }
+
+  void emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
+                         DiagnosticsEngine::Level Level,
+                         ArrayRef<CharSourceRange> Ranges,
+                         const SourceManager &SM) override {}
+
+  void emitCodeContext(SourceLocation Loc, DiagnosticsEngine::Level Level,
+                       SmallVectorImpl<CharSourceRange> &Ranges,
+                       ArrayRef<FixItHint> Hints,
+                       const SourceManager &SM) override {
+    assert(Loc.isValid());
+    for (const auto &FixIt : Hints) {
+      CharSourceRange Range = FixIt.RemoveRange;
+      assert(Range.getBegin().isValid() && Range.getEnd().isValid() &&
+             "Invalid range in the fix-it hint.");
+      assert(Range.getBegin().isFileID() && Range.getEnd().isFileID() &&
+             "Only file locations supported in fix-it hints.");
+
+      tooling::Replacement Replacement(SM, Range, FixIt.CodeToInsert);
+      llvm::Error Err = Error.Fix[Replacement.getFilePath()].add(Replacement);
+      // FIXME: better error handling (at least, don't let other replacements be
+      // applied).
+      if (Err) {
+        llvm::errs() << "Fix conflicts with existing fix! "
+                     << llvm::toString(std::move(Err)) << "\n";
+        assert(false && "Fix conflicts with existing fix!");
+      }
+    }
+  }
+
+  void emitIncludeLocation(SourceLocation Loc, PresumedLoc PLoc,
+                           const SourceManager &SM) override {}
+
+  void emitImportLocation(SourceLocation Loc, PresumedLoc PLoc,
+                          StringRef ModuleName,
+                          const SourceManager &SM) override {}
+
+  void emitBuildingModuleLocation(SourceLocation Loc, PresumedLoc PLoc,
+                                  StringRef ModuleName,
+                                  const SourceManager &SM) override {}
+
+  void endDiagnostic(DiagOrStoredDiag D,
+                     DiagnosticsEngine::Level Level) override {
+    assert(!Error.Message.Message.empty() && "Message has not been set");
+  }
+
+private:
+  ClangTidyError &Error;
+};
+} // end anonymous namespace
+
+ClangTidyError::ClangTidyError(StringRef CheckName,
+                               ClangTidyError::Level DiagLevel,
+                               StringRef BuildDirectory, bool IsWarningAsError)
+    : tooling::Diagnostic(CheckName, DiagLevel, BuildDirectory),
+      IsWarningAsError(IsWarningAsError) {}
+
+// Returns true if GlobList starts with the negative indicator ('-'), removes it
+// from the GlobList.
+static bool ConsumeNegativeIndicator(StringRef &GlobList) {
+  GlobList = GlobList.trim(' ');
+  if (GlobList.startswith("-")) {
+    GlobList = GlobList.substr(1);
+    return true;
+  }
+  return false;
+}
+// Converts first glob from the comma-separated list of globs to Regex and
+// removes it and the trailing comma from the GlobList.
+static llvm::Regex ConsumeGlob(StringRef &GlobList) {
+  StringRef UntrimmedGlob = GlobList.substr(0, GlobList.find(','));
+  StringRef Glob = UntrimmedGlob.trim(' ');
+  GlobList = GlobList.substr(UntrimmedGlob.size() + 1);
+  SmallString<128> RegexText("^");
+  StringRef MetaChars("()^$|*+?.[]\\{}");
+  for (char C : Glob) {
+    if (C == '*')
+      RegexText.push_back('.');
+    else if (MetaChars.find(C) != StringRef::npos)
+      RegexText.push_back('\\');
+    RegexText.push_back(C);
+  }
+  RegexText.push_back('$');
+  return llvm::Regex(RegexText);
+}
+
+GlobList::GlobList(StringRef Globs)
+    : Positive(!ConsumeNegativeIndicator(Globs)), Regex(ConsumeGlob(Globs)),
+      NextGlob(Globs.empty() ? nullptr : new GlobList(Globs)) {}
+
+bool GlobList::contains(StringRef S, bool Contains) {
+  if (Regex.match(S))
+    Contains = Positive;
+
+  if (NextGlob)
+    Contains = NextGlob->contains(S, Contains);
+  return Contains;
+}
+
+ClangTidyContext::ClangTidyContext(
+    std::unique_ptr<ClangTidyOptionsProvider> OptionsProvider)
+    : DiagEngine(nullptr), OptionsProvider(std::move(OptionsProvider)),
+      Profile(nullptr) {
+  // Before the first translation unit we can get errors related to command-line
+  // parsing, use empty string for the file name in this case.
+  setCurrentFile("");
+}
+
+DiagnosticBuilder ClangTidyContext::diag(
+    StringRef CheckName, SourceLocation Loc, StringRef Description,
+    DiagnosticIDs::Level Level /* = DiagnosticIDs::Warning*/) {
+  assert(Loc.isValid());
+  unsigned ID = DiagEngine->getDiagnosticIDs()->getCustomDiagID(
+      Level, (Description + " [" + CheckName + "]").str());
+  CheckNamesByDiagnosticID.try_emplace(ID, CheckName);
+  return DiagEngine->Report(Loc, ID);
+}
+
+void ClangTidyContext::setDiagnosticsEngine(DiagnosticsEngine *Engine) {
+  DiagEngine = Engine;
+}
+
+void ClangTidyContext::setSourceManager(SourceManager *SourceMgr) {
+  DiagEngine->setSourceManager(SourceMgr);
+}
+
+void ClangTidyContext::setCurrentFile(StringRef File) {
+  CurrentFile = File;
+  CurrentOptions = getOptionsForFile(CurrentFile);
+  CheckFilter.reset(new GlobList(*getOptions().Checks));
+  WarningAsErrorFilter.reset(new GlobList(*getOptions().WarningsAsErrors));
+}
+
+void ClangTidyContext::setASTContext(ASTContext *Context) {
+  DiagEngine->SetArgToStringFn(&FormatASTNodeDiagnosticArgument, Context);
+  LangOpts = Context->getLangOpts();
+}
+
+const ClangTidyGlobalOptions &ClangTidyContext::getGlobalOptions() const {
+  return OptionsProvider->getGlobalOptions();
+}
+
+const ClangTidyOptions &ClangTidyContext::getOptions() const {
+  return CurrentOptions;
+}
+
+ClangTidyOptions ClangTidyContext::getOptionsForFile(StringRef File) const {
+  // Merge options on top of getDefaults() as a safeguard against options with
+  // unset values.
+  return ClangTidyOptions::getDefaults().mergeWith(
+      OptionsProvider->getOptions(File));
+}
+
+void ClangTidyContext::setCheckProfileData(ProfileData *P) { Profile = P; }
+
+GlobList &ClangTidyContext::getChecksFilter() {
+  assert(CheckFilter != nullptr);
+  return *CheckFilter;
+}
+
+GlobList &ClangTidyContext::getWarningAsErrorFilter() {
+  assert(WarningAsErrorFilter != nullptr);
+  return *WarningAsErrorFilter;
+}
+
+/// \brief Store a \c ClangTidyError.
+void ClangTidyContext::storeError(const ClangTidyError &Error) {
+  Errors.push_back(Error);
+}
+
+StringRef ClangTidyContext::getCheckName(unsigned DiagnosticID) const {
+  llvm::DenseMap<unsigned, std::string>::const_iterator I =
+      CheckNamesByDiagnosticID.find(DiagnosticID);
+  if (I != CheckNamesByDiagnosticID.end())
+    return I->second;
+  return "";
+}
+
+ClangTidyDiagnosticConsumer::ClangTidyDiagnosticConsumer(ClangTidyContext &Ctx)
+    : Context(Ctx), LastErrorRelatesToUserCode(false),
+      LastErrorPassesLineFilter(false), LastErrorWasIgnored(false) {
+  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+  Diags.reset(new DiagnosticsEngine(
+      IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs), &*DiagOpts, this,
+      /*ShouldOwnClient=*/false));
+  Context.setDiagnosticsEngine(Diags.get());
+}
+
+void ClangTidyDiagnosticConsumer::finalizeLastError() {
+  if (!Errors.empty()) {
+    ClangTidyError &Error = Errors.back();
+    if (!Context.getChecksFilter().contains(Error.DiagnosticName) &&
+        Error.DiagLevel != ClangTidyError::Error) {
+      ++Context.Stats.ErrorsIgnoredCheckFilter;
+      Errors.pop_back();
+    } else if (!LastErrorRelatesToUserCode) {
+      ++Context.Stats.ErrorsIgnoredNonUserCode;
+      Errors.pop_back();
+    } else if (!LastErrorPassesLineFilter) {
+      ++Context.Stats.ErrorsIgnoredLineFilter;
+      Errors.pop_back();
+    } else {
+      ++Context.Stats.ErrorsDisplayed;
+    }
+  }
+  LastErrorRelatesToUserCode = false;
+  LastErrorPassesLineFilter = false;
+}
+
+static bool LineIsMarkedWithNOLINT(SourceManager &SM, SourceLocation Loc) {
+  bool Invalid;
+  const char *CharacterData = SM.getCharacterData(Loc, &Invalid);
+  if (Invalid)
+    return false;
+
+  // Check if there's a NOLINT on this line.
+  const char *P = CharacterData;
+  while (*P != '\0' && *P != '\r' && *P != '\n')
+    ++P;
+  StringRef RestOfLine(CharacterData, P - CharacterData + 1);
+  // FIXME: Handle /\bNOLINT\b(\([^)]*\))?/ as cpplint.py does.
+  if (RestOfLine.find("NOLINT") != StringRef::npos)
+    return true;
+
+  // Check if there's a NOLINTNEXTLINE on the previous line.
+  const char *BufBegin =
+      SM.getCharacterData(SM.getLocForStartOfFile(SM.getFileID(Loc)), &Invalid);
+  if (Invalid || P == BufBegin)
+    return false;
+
+  // Scan backwards over the current line.
+  P = CharacterData;
+  while (P != BufBegin && *P != '\n')
+    --P;
+
+  // If we reached the begin of the file there is no line before it.
+  if (P == BufBegin)
+    return false;
+
+  // Skip over the newline.
+  --P;
+  const char *LineEnd = P;
+
+  // Now we're on the previous line. Skip to the beginning of it.
+  while (P != BufBegin && *P != '\n')
+    --P;
+
+  RestOfLine = StringRef(P, LineEnd - P + 1);
+  if (RestOfLine.find("NOLINTNEXTLINE") != StringRef::npos)
+    return true;
+
+  return false;
+}
+
+static bool LineIsMarkedWithNOLINTinMacro(SourceManager &SM,
+                                          SourceLocation Loc) {
+  while (true) {
+    if (LineIsMarkedWithNOLINT(SM, Loc))
+      return true;
+    if (!Loc.isMacroID())
+      return false;
+    Loc = SM.getImmediateExpansionRange(Loc).first;
+  }
+  return false;
+}
+
+void ClangTidyDiagnosticConsumer::HandleDiagnostic(
+    DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info) {
+  if (LastErrorWasIgnored && DiagLevel == DiagnosticsEngine::Note)
+    return;
+
+  if (Info.getLocation().isValid() && DiagLevel != DiagnosticsEngine::Error &&
+      DiagLevel != DiagnosticsEngine::Fatal &&
+      LineIsMarkedWithNOLINTinMacro(Diags->getSourceManager(),
+                                    Info.getLocation())) {
+    ++Context.Stats.ErrorsIgnoredNOLINT;
+    // Ignored a warning, should ignore related notes as well
+    LastErrorWasIgnored = true;
+    return;
+  }
+
+  LastErrorWasIgnored = false;
+  // Count warnings/errors.
+  DiagnosticConsumer::HandleDiagnostic(DiagLevel, Info);
+
+  if (DiagLevel == DiagnosticsEngine::Note) {
+    assert(!Errors.empty() &&
+           "A diagnostic note can only be appended to a message.");
+  } else {
+    finalizeLastError();
+    StringRef WarningOption =
+        Context.DiagEngine->getDiagnosticIDs()->getWarningOptionForDiag(
+            Info.getID());
+    std::string CheckName = !WarningOption.empty()
+                                ? ("clang-diagnostic-" + WarningOption).str()
+                                : Context.getCheckName(Info.getID()).str();
+
+    if (CheckName.empty()) {
+      // This is a compiler diagnostic without a warning option. Assign check
+      // name based on its level.
+      switch (DiagLevel) {
+      case DiagnosticsEngine::Error:
+      case DiagnosticsEngine::Fatal:
+        CheckName = "clang-diagnostic-error";
+        break;
+      case DiagnosticsEngine::Warning:
+        CheckName = "clang-diagnostic-warning";
+        break;
+      default:
+        CheckName = "clang-diagnostic-unknown";
+        break;
+      }
+    }
+
+    ClangTidyError::Level Level = ClangTidyError::Warning;
+    if (DiagLevel == DiagnosticsEngine::Error ||
+        DiagLevel == DiagnosticsEngine::Fatal) {
+      // Force reporting of Clang errors regardless of filters and non-user
+      // code.
+      Level = ClangTidyError::Error;
+      LastErrorRelatesToUserCode = true;
+      LastErrorPassesLineFilter = true;
+    }
+    bool IsWarningAsError =
+        DiagLevel == DiagnosticsEngine::Warning &&
+        Context.getWarningAsErrorFilter().contains(CheckName);
+    Errors.emplace_back(CheckName, Level, Context.getCurrentBuildDirectory(),
+                        IsWarningAsError);
+  }
+
+  ClangTidyDiagnosticRenderer Converter(
+      Context.getLangOpts(), &Context.DiagEngine->getDiagnosticOptions(),
+      Errors.back());
+  SmallString<100> Message;
+  Info.FormatDiagnostic(Message);
+  SourceManager *Sources = nullptr;
+  if (Info.hasSourceManager())
+    Sources = &Info.getSourceManager();
+  Converter.emitDiagnostic(Info.getLocation(), DiagLevel, Message,
+                           Info.getRanges(), Info.getFixItHints(), Sources);
+
+  checkFilters(Info.getLocation());
+}
+
+bool ClangTidyDiagnosticConsumer::passesLineFilter(StringRef FileName,
+                                                   unsigned LineNumber) const {
+  if (Context.getGlobalOptions().LineFilter.empty())
+    return true;
+  for (const FileFilter &Filter : Context.getGlobalOptions().LineFilter) {
+    if (FileName.endswith(Filter.Name)) {
+      if (Filter.LineRanges.empty())
+        return true;
+      for (const FileFilter::LineRange &Range : Filter.LineRanges) {
+        if (Range.first <= LineNumber && LineNumber <= Range.second)
+          return true;
+      }
+      return false;
+    }
+  }
+  return false;
+}
+
+void ClangTidyDiagnosticConsumer::checkFilters(SourceLocation Location) {
+  // Invalid location may mean a diagnostic in a command line, don't skip these.
+  if (!Location.isValid()) {
+    LastErrorRelatesToUserCode = true;
+    LastErrorPassesLineFilter = true;
+    return;
+  }
+
+  const SourceManager &Sources = Diags->getSourceManager();
+  if (!*Context.getOptions().SystemHeaders &&
+      Sources.isInSystemHeader(Location))
+    return;
+
+  // FIXME: We start with a conservative approach here, but the actual type of
+  // location needed depends on the check (in particular, where this check wants
+  // to apply fixes).
+  FileID FID = Sources.getDecomposedExpansionLoc(Location).first;
+  const FileEntry *File = Sources.getFileEntryForID(FID);
+
+  // -DMACRO definitions on the command line have locations in a virtual buffer
+  // that doesn't have a FileEntry. Don't skip these as well.
+  if (!File) {
+    LastErrorRelatesToUserCode = true;
+    LastErrorPassesLineFilter = true;
+    return;
+  }
+
+  StringRef FileName(File->getName());
+  LastErrorRelatesToUserCode = LastErrorRelatesToUserCode ||
+                               Sources.isInMainFile(Location) ||
+                               getHeaderFilter()->match(FileName);
+
+  unsigned LineNumber = Sources.getExpansionLineNumber(Location);
+  LastErrorPassesLineFilter =
+      LastErrorPassesLineFilter || passesLineFilter(FileName, LineNumber);
+}
+
+llvm::Regex *ClangTidyDiagnosticConsumer::getHeaderFilter() {
+  if (!HeaderFilter)
+    HeaderFilter.reset(
+        new llvm::Regex(*Context.getOptions().HeaderFilterRegex));
+  return HeaderFilter.get();
+}
+
+void ClangTidyDiagnosticConsumer::removeIncompatibleErrors(
+    SmallVectorImpl<ClangTidyError> &Errors) const {
+  // Each error is modelled as the set of intervals in which it applies
+  // replacements. To detect overlapping replacements, we use a sweep line
+  // algorithm over these sets of intervals.
+  // An event here consists of the opening or closing of an interval. During the
+  // process, we maintain a counter with the amount of open intervals. If we
+  // find an endpoint of an interval and this counter is different from 0, it
+  // means that this interval overlaps with another one, so we set it as
+  // inapplicable.
+  struct Event {
+    // An event can be either the begin or the end of an interval.
+    enum EventType {
+      ET_Begin = 1,
+      ET_End = -1,
+    };
+
+    Event(unsigned Begin, unsigned End, EventType Type, unsigned ErrorId,
+          unsigned ErrorSize)
+        : Type(Type), ErrorId(ErrorId) {
+      // The events are going to be sorted by their position. In case of draw:
+      //
+      // * If an interval ends at the same position at which other interval
+      //   begins, this is not an overlapping, so we want to remove the ending
+      //   interval before adding the starting one: end events have higher
+      //   priority than begin events.
+      //
+      // * If we have several begin points at the same position, we will mark as
+      //   inapplicable the ones that we process later, so the first one has to
+      //   be the one with the latest end point, because this one will contain
+      //   all the other intervals. For the same reason, if we have several end
+      //   points in the same position, the last one has to be the one with the
+      //   earliest begin point. In both cases, we sort non-increasingly by the
+      //   position of the complementary.
+      //
+      // * In case of two equal intervals, the one whose error is bigger can
+      //   potentially contain the other one, so we want to process its begin
+      //   points before and its end points later.
+      //
+      // * Finally, if we have two equal intervals whose errors have the same
+      //   size, none of them will be strictly contained inside the other.
+      //   Sorting by ErrorId will guarantee that the begin point of the first
+      //   one will be processed before, disallowing the second one, and the
+      //   end point of the first one will also be processed before,
+      //   disallowing the first one.
+      if (Type == ET_Begin)
+        Priority = std::make_tuple(Begin, Type, -End, -ErrorSize, ErrorId);
+      else
+        Priority = std::make_tuple(End, Type, -Begin, ErrorSize, ErrorId);
+    }
+
+    bool operator<(const Event &Other) const {
+      return Priority < Other.Priority;
+    }
+
+    // Determines if this event is the begin or the end of an interval.
+    EventType Type;
+    // The index of the error to which the interval that generated this event
+    // belongs.
+    unsigned ErrorId;
+    // The events will be sorted based on this field.
+    std::tuple<unsigned, EventType, int, int, unsigned> Priority;
+  };
+
+  // Compute error sizes.
+  std::vector<int> Sizes;
+  for (const auto &Error : Errors) {
+    int Size = 0;
+    for (const auto &FileAndReplaces : Error.Fix) {
+      for (const auto &Replace : FileAndReplaces.second)
+        Size += Replace.getLength();
+    }
+    Sizes.push_back(Size);
+  }
+
+  // Build events from error intervals.
+  std::map<std::string, std::vector<Event>> FileEvents;
+  for (unsigned I = 0; I < Errors.size(); ++I) {
+    for (const auto &FileAndReplace : Errors[I].Fix) {
+      for (const auto &Replace : FileAndReplace.second) {
+        unsigned Begin = Replace.getOffset();
+        unsigned End = Begin + Replace.getLength();
+        const std::string &FilePath = Replace.getFilePath();
+        // FIXME: Handle empty intervals, such as those from insertions.
+        if (Begin == End)
+          continue;
+        auto &Events = FileEvents[FilePath];
+        Events.emplace_back(Begin, End, Event::ET_Begin, I, Sizes[I]);
+        Events.emplace_back(Begin, End, Event::ET_End, I, Sizes[I]);
+      }
+    }
+  }
+
+  std::vector<bool> Apply(Errors.size(), true);
+  for (auto &FileAndEvents : FileEvents) {
+    std::vector<Event> &Events = FileAndEvents.second;
+    // Sweep.
+    std::sort(Events.begin(), Events.end());
+    int OpenIntervals = 0;
+    for (const auto &Event : Events) {
+      if (Event.Type == Event::ET_End)
+        --OpenIntervals;
+      // This has to be checked after removing the interval from the count if it
+      // is an end event, or before adding it if it is a begin event.
+      if (OpenIntervals != 0)
+        Apply[Event.ErrorId] = false;
+      if (Event.Type == Event::ET_Begin)
+        ++OpenIntervals;
+    }
+    assert(OpenIntervals == 0 && "Amount of begin/end points doesn't match");
+  }
+
+  for (unsigned I = 0; I < Errors.size(); ++I) {
+    if (!Apply[I]) {
+      Errors[I].Fix.clear();
+      Errors[I].Notes.emplace_back(
+          "this fix will not be applied because it overlaps with another fix");
+    }
+  }
+}
+
+namespace {
+struct LessClangTidyError {
+  bool operator()(const ClangTidyError &LHS, const ClangTidyError &RHS) const {
+    const tooling::DiagnosticMessage &M1 = LHS.Message;
+    const tooling::DiagnosticMessage &M2 = RHS.Message;
+
+    return std::tie(M1.FilePath, M1.FileOffset, M1.Message) <
+           std::tie(M2.FilePath, M2.FileOffset, M2.Message);
+  }
+};
+struct EqualClangTidyError {
+  bool operator()(const ClangTidyError &LHS, const ClangTidyError &RHS) const {
+    LessClangTidyError Less;
+    return !Less(LHS, RHS) && !Less(RHS, LHS);
+  }
+};
+} // end anonymous namespace
+
+// Flushes the internal diagnostics buffer to the ClangTidyContext.
+void ClangTidyDiagnosticConsumer::finish() {
+  finalizeLastError();
+
+  std::sort(Errors.begin(), Errors.end(), LessClangTidyError());
+  Errors.erase(std::unique(Errors.begin(), Errors.end(), EqualClangTidyError()),
+               Errors.end());
+  removeIncompatibleErrors(Errors);
+
+  for (const ClangTidyError &Error : Errors)
+    Context.storeError(Error);
+  Errors.clear();
+}

unittests/clang-tidy/ClangTidyDiagnosticConsumerTest.cpp

-#include "ClangTidy.h"
-#include "ClangTidyTest.h"
-#include "gtest/gtest.h"
-
-namespace clang {
-namespace tidy {
-namespace test {
-
-class TestCheck : public ClangTidyCheck {
-public:
-  TestCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
-  void registerMatchers(ast_matchers::MatchFinder *Finder) override {
-    Finder->addMatcher(ast_matchers::varDecl().bind("var"), this);
-  }
-  void check(const ast_matchers::MatchFinder::MatchResult &Result) override {
-    const auto *Var = Result.Nodes.getNodeAs<VarDecl>("var");
-    // Add diagnostics in the wrong order.
-    diag(Var->getLocation(), "variable");
-    diag(Var->getTypeSpecStartLoc(), "type specifier");
-  }
-};
-
-TEST(ClangTidyDiagnosticConsumer, SortsErrors) {
-  std::vector<ClangTidyError> Errors;
-  runCheckOnCode<TestCheck>("int a;", &Errors);
-  EXPECT_EQ(2ul, Errors.size());
-  EXPECT_EQ("type specifier", Errors[0].Message.Message);
-  EXPECT_EQ("variable", Errors[1].Message.Message);
-}
-
-TEST(GlobList, Empty) {
-  GlobList Filter("");
-
-  EXPECT_TRUE(Filter.contains(""));
-  EXPECT_FALSE(Filter.contains("aaa"));
-}
-
-TEST(GlobList, Nothing) {
-  GlobList Filter("-*");
-
-  EXPECT_FALSE(Filter.contains(""));
-  EXPECT_FALSE(Filter.contains("a"));
-  EXPECT_FALSE(Filter.contains("-*"));
-  EXPECT_FALSE(Filter.contains("-"));
-  EXPECT_FALSE(Filter.contains("*"));
-}
-
-TEST(GlobList, Everything) {
-  GlobList Filter("*");
-
-  EXPECT_TRUE(Filter.contains(""));
-  EXPECT_TRUE(Filter.contains("aaaa"));
-  EXPECT_TRUE(Filter.contains("-*"));
-  EXPECT_TRUE(Filter.contains("-"));
-  EXPECT_TRUE(Filter.contains("*"));
-}
-
-TEST(GlobList, Simple) {
-  GlobList Filter("aaa");
-
-  EXPECT_TRUE(Filter.contains("aaa"));
-  EXPECT_FALSE(Filter.contains(""));
-  EXPECT_FALSE(Filter.contains("aa"));
-  EXPECT_FALSE(Filter.contains("aaaa"));
-  EXPECT_FALSE(Filter.contains("bbb"));
-}
-
-TEST(GlobList, Complex) {
-  GlobList Filter("*,-a.*, -b.*,   a.1.* ,-a.1.A.*,-..,-...,-..+,-*$, -*qwe* ");
-
-  EXPECT_TRUE(Filter.contains("aaa"));
-  EXPECT_TRUE(Filter.contains("qqq"));
-  EXPECT_FALSE(Filter.contains("a."));
-  EXPECT_FALSE(Filter.contains("a.b"));
-  EXPECT_FALSE(Filter.contains("b."));
-  EXPECT_FALSE(Filter.contains("b.b"));
-  EXPECT_TRUE(Filter.contains("a.1.b"));
-  EXPECT_FALSE(Filter.contains("a.1.A.a"));
-  EXPECT_FALSE(Filter.contains("qwe"));
-  EXPECT_FALSE(Filter.contains("asdfqweasdf"));
-  EXPECT_TRUE(Filter.contains("asdfqwEasdf"));
-}
-
-} // namespace test
-} // namespace tidy
-} // namespace clang
+#include "ClangTidy.h"
+#include "ClangTidyTest.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace tidy {
+namespace test {
+
+class TestCheck : public ClangTidyCheck {
+public:
+  TestCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override {
+    Finder->addMatcher(ast_matchers::varDecl().bind("var"), this);
+  }
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override {
+    const auto *Var = Result.Nodes.getNodeAs<VarDecl>("var");
+    // Add diagnostics in the wrong order.
+    diag(Var->getLocation(), "variable");
+    diag(Var->getTypeSpecStartLoc(), "type specifier");
+  }
+};
+
+TEST(ClangTidyDiagnosticConsumer, SortsErrors) {
+  std::vector<ClangTidyError> Errors;
+  runCheckOnCode<TestCheck>("int a;", &Errors);
+  EXPECT_EQ(2ul, Errors.size());
+  EXPECT_EQ("type specifier", Errors[0].Message.Message);
+  EXPECT_EQ("variable", Errors[1].Message.Message);
+}
+
+TEST(GlobList, Empty) {
+  GlobList Filter("");
+
+  EXPECT_TRUE(Filter.contains(""));
+  EXPECT_FALSE(Filter.contains("aaa"));
+}
+
+TEST(GlobList, Nothing) {
+  GlobList Filter("-*");
+
+  EXPECT_FALSE(Filter.contains(""));
+  EXPECT_FALSE(Filter.contains("a"));
+  EXPECT_FALSE(Filter.contains("-*"));
+  EXPECT_FALSE(Filter.contains("-"));
+  EXPECT_FALSE(Filter.contains("*"));
+}
+
+TEST(GlobList, Everything) {
+  GlobList Filter("*");
+
+  EXPECT_TRUE(Filter.contains(""));
+  EXPECT_TRUE(Filter.contains("aaaa"));
+  EXPECT_TRUE(Filter.contains("-*"));
+  EXPECT_TRUE(Filter.contains("-"));
+  EXPECT_TRUE(Filter.contains("*"));
+}
+
+TEST(GlobList, Simple) {
+  GlobList Filter("aaa");
+
+  EXPECT_TRUE(Filter.contains("aaa"));
+  EXPECT_FALSE(Filter.contains(""));
+  EXPECT_FALSE(Filter.contains("aa"));
+  EXPECT_FALSE(Filter.contains("aaaa"));
+  EXPECT_FALSE(Filter.contains("bbb"));
+}
+
+TEST(GlobList, WhitespacesAtBegin) {
+  GlobList Filter("-*,   a.b.*");
+
+  EXPECT_TRUE(Filter.contains("a.b.c"));
+  EXPECT_FALSE(Filter.contains("b.c"));
+}
+
+TEST(GlobList, Complex) {
+  GlobList Filter("*,-a.*, -b.*,   a.1.* ,-a.1.A.*,-..,-...,-..+,-*$, -*qwe* ");
+
+  EXPECT_TRUE(Filter.contains("aaa"));
+  EXPECT_TRUE(Filter.contains("qqq"));
+  EXPECT_FALSE(Filter.contains("a."));
+  EXPECT_FALSE(Filter.contains("a.b"));
+  EXPECT_FALSE(Filter.contains("b."));
+  EXPECT_FALSE(Filter.contains("b.b"));
+  EXPECT_TRUE(Filter.contains("a.1.b"));
+  EXPECT_FALSE(Filter.contains("a.1.A.a"));
+  EXPECT_FALSE(Filter.contains("qwe"));
+  EXPECT_FALSE(Filter.contains("asdfqweasdf"));
+  EXPECT_TRUE(Filter.contains("asdfqwEasdf"));
+}
+
+} // namespace test
+} // namespace tidy
+} // namespace clang