Re-land "Cache the locations of NOLINTBEGIN/END blocks" with fix for build bot

Author: salman-javed-nz

clang-tools-extra/clang-tidy/CMakeLists.txt

@@ -17,6 +17,7 @@ add_clang_library(clangTidy
   ClangTidyProfiling.cpp
   ExpandModularHeadersPPCallbacks.cpp
   GlobList.cpp
+  NoLintDirectiveHandler.cpp
 
   DEPENDS
   ClangSACheckers

clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp

@@ -18,6 +18,7 @@
 #include "ClangTidyDiagnosticConsumer.h"
 #include "ClangTidyOptions.h"
 #include "GlobList.h"
+#include "NoLintDirectiveHandler.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTDiagnostic.h"
 #include "clang/AST/Attr.h"
@@ -188,7 +189,7 @@ DiagnosticBuilder ClangTidyContext::diag(
   return DiagEngine->Report(ID);
 }
 
-DiagnosticBuilder ClangTidyContext::diag(const ClangTidyError &Error) {
+DiagnosticBuilder ClangTidyContext::diag(const tooling::Diagnostic &Error) {
   SourceManager &SM = DiagEngine->getSourceManager();
   llvm::ErrorOr<const FileEntry *> File =
       SM.getFileManager().getFile(Error.Message.FilePath);
@@ -206,6 +207,15 @@ DiagnosticBuilder ClangTidyContext::configurationDiag(
   return diag("clang-tidy-config", Message, Level);
 }
 
+bool ClangTidyContext::shouldSuppressDiagnostic(
+    DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info,
+    SmallVectorImpl<tooling::Diagnostic> &NoLintErrors, bool AllowIO,
+    bool EnableNoLintBlocks) {
+  std::string CheckName = getCheckName(Info.getID());
+  return NoLintHandler.shouldSuppress(DiagLevel, Info, CheckName, NoLintErrors,
+                                      AllowIO, EnableNoLintBlocks);
+}
+
 void ClangTidyContext::setSourceManager(SourceManager *SourceMgr) {
   DiagEngine->setSourceManager(SourceMgr);
 }
@@ -307,218 +317,9 @@ void ClangTidyDiagnosticConsumer::finalizeLastError() {
   LastErrorPassesLineFilter = false;
 }
 
-static bool isNOLINTFound(StringRef NolintDirectiveText, StringRef CheckName,
-                          StringRef Line, size_t *FoundNolintIndex = nullptr,
-                          StringRef *FoundNolintChecksStr = nullptr) {
-  if (FoundNolintIndex)
-    *FoundNolintIndex = StringRef::npos;
-  if (FoundNolintChecksStr)
-    *FoundNolintChecksStr = StringRef();
-
-  size_t NolintIndex = Line.find(NolintDirectiveText);
-  if (NolintIndex == StringRef::npos)
-    return false;
-
-  size_t BracketIndex = NolintIndex + NolintDirectiveText.size();
-  if (BracketIndex < Line.size() && isalnum(Line[BracketIndex])) {
-    // Reject this search result, otherwise it will cause false positives when
-    // NOLINT is found as a substring of NOLINT(NEXTLINE/BEGIN/END).
-    return false;
-  }
-
-  // Check if specific checks are specified in brackets.
-  if (BracketIndex < Line.size() && Line[BracketIndex] == '(') {
-    ++BracketIndex;
-    const size_t BracketEndIndex = Line.find(')', BracketIndex);
-    if (BracketEndIndex != StringRef::npos) {
-      StringRef ChecksStr =
-          Line.substr(BracketIndex, BracketEndIndex - BracketIndex);
-      if (FoundNolintChecksStr)
-        *FoundNolintChecksStr = ChecksStr;
-      // Allow specifying a few checks with a glob expression, ignoring
-      // negative globs (which would effectively disable the suppression).
-      GlobList Globs(ChecksStr, /*KeepNegativeGlobs=*/false);
-      if (!Globs.contains(CheckName))
-        return false;
-    }
-  }
-
-  if (FoundNolintIndex)
-    *FoundNolintIndex = NolintIndex;
-
-  return true;
-}
-
-static llvm::Optional<StringRef> getBuffer(const SourceManager &SM, FileID File,
-                                           bool AllowIO) {
-  return AllowIO ? SM.getBufferDataOrNone(File)
-                 : SM.getBufferDataIfLoaded(File);
-}
-
-static ClangTidyError createNolintError(const ClangTidyContext &Context,
-                                        const SourceManager &SM,
-                                        SourceLocation Loc,
-                                        bool IsNolintBegin) {
-  ClangTidyError Error("clang-tidy-nolint", ClangTidyError::Error,
-                       Context.getCurrentBuildDirectory(), false);
-  StringRef Message =
-      IsNolintBegin
-          ? ("unmatched 'NOLINTBEGIN' comment without a subsequent 'NOLINT"
-             "END' comment")
-          : ("unmatched 'NOLINTEND' comment without a previous 'NOLINT"
-             "BEGIN' comment");
-  Error.Message = tooling::DiagnosticMessage(Message, SM, Loc);
-  return Error;
-}
-
-static Optional<ClangTidyError> tallyNolintBegins(
-    const ClangTidyContext &Context, const SourceManager &SM,
-    StringRef CheckName, SmallVector<StringRef> Lines, SourceLocation LinesLoc,
-    SmallVector<std::pair<SourceLocation, StringRef>> &NolintBegins) {
-  // Keep a running total of how many NOLINT(BEGIN...END) blocks are active, as
-  // well as the bracket expression (if any) that was used in the NOLINT
-  // expression.
-  size_t NolintIndex;
-  StringRef NolintChecksStr;
-  for (const auto &Line : Lines) {
-    if (isNOLINTFound("NOLINTBEGIN", CheckName, Line, &NolintIndex,
-                      &NolintChecksStr)) {
-      // Check if a new block is being started.
-      NolintBegins.emplace_back(std::make_pair(
-          LinesLoc.getLocWithOffset(NolintIndex), NolintChecksStr));
-    } else if (isNOLINTFound("NOLINTEND", CheckName, Line, &NolintIndex,
-                             &NolintChecksStr)) {
-      // Check if the previous block is being closed.
-      if (!NolintBegins.empty() &&
-          NolintBegins.back().second == NolintChecksStr) {
-        NolintBegins.pop_back();
-      } else {
-        // Trying to close a nonexistent block. Return a diagnostic about this
-        // misuse that can be displayed along with the original clang-tidy check
-        // that the user was attempting to suppress.
-        return createNolintError(Context, SM,
-                                 LinesLoc.getLocWithOffset(NolintIndex), false);
-      }
-    }
-    // Advance source location to the next line.
-    LinesLoc = LinesLoc.getLocWithOffset(Line.size() + sizeof('\n'));
-  }
-  return None; // All NOLINT(BEGIN/END) use has been consistent so far.
-}
-
-static bool
-lineIsWithinNolintBegin(const ClangTidyContext &Context,
-                        SmallVectorImpl<ClangTidyError> &SuppressionErrors,
-                        const SourceManager &SM, SourceLocation Loc,
-                        StringRef CheckName, StringRef TextBeforeDiag,
-                        StringRef TextAfterDiag) {
-  Loc = SM.getExpansionRange(Loc).getBegin();
-  SourceLocation FileStartLoc = SM.getLocForStartOfFile(SM.getFileID(Loc));
-  SmallVector<std::pair<SourceLocation, StringRef>> NolintBegins;
-
-  // Check if there's an open NOLINT(BEGIN...END) block on the previous lines.
-  SmallVector<StringRef> PrevLines;
-  TextBeforeDiag.split(PrevLines, '\n');
-  auto Error = tallyNolintBegins(Context, SM, CheckName, PrevLines,
-                                 FileStartLoc, NolintBegins);
-  if (Error) {
-    SuppressionErrors.emplace_back(Error.getValue());
-  }
-  bool WithinNolintBegin = !NolintBegins.empty();
-
-  // Check that every block is terminated correctly on the following lines.
-  SmallVector<StringRef> FollowingLines;
-  TextAfterDiag.split(FollowingLines, '\n');
-  Error = tallyNolintBegins(Context, SM, CheckName, FollowingLines, Loc,
-                            NolintBegins);
-  if (Error) {
-    SuppressionErrors.emplace_back(Error.getValue());
-  }
-
-  // The following blocks were never closed. Return diagnostics for each
-  // instance that can be displayed along with the original clang-tidy check
-  // that the user was attempting to suppress.
-  for (const auto &NolintBegin : NolintBegins) {
-    SuppressionErrors.emplace_back(
-        createNolintError(Context, SM, NolintBegin.first, true));
-  }
-
-  return WithinNolintBegin && SuppressionErrors.empty();
-}
-
-static bool
-lineIsMarkedWithNOLINT(const ClangTidyContext &Context,
-                       SmallVectorImpl<ClangTidyError> &SuppressionErrors,
-                       bool AllowIO, const SourceManager &SM,
-                       SourceLocation Loc, StringRef CheckName,
-                       bool EnableNolintBlocks) {
-  // Get source code for this location.
-  FileID File;
-  unsigned Offset;
-  std::tie(File, Offset) = SM.getDecomposedSpellingLoc(Loc);
-  Optional<StringRef> Buffer = getBuffer(SM, File, AllowIO);
-  if (!Buffer)
-    return false;
-
-  // Check if there's a NOLINT on this line.
-  StringRef TextAfterDiag = Buffer->substr(Offset);
-  StringRef RestOfThisLine, FollowingLines;
-  std::tie(RestOfThisLine, FollowingLines) = TextAfterDiag.split('\n');
-  if (isNOLINTFound("NOLINT", CheckName, RestOfThisLine))
-    return true;
-
-  // Check if there's a NOLINTNEXTLINE on the previous line.
-  StringRef TextBeforeDiag = Buffer->substr(0, Offset);
-  size_t LastNewLinePos = TextBeforeDiag.rfind('\n');
-  StringRef PrevLines = (LastNewLinePos == StringRef::npos)
-                            ? StringRef()
-                            : TextBeforeDiag.slice(0, LastNewLinePos);
-  LastNewLinePos = PrevLines.rfind('\n');
-  StringRef PrevLine = (LastNewLinePos == StringRef::npos)
-                           ? PrevLines
-                           : PrevLines.substr(LastNewLinePos + 1);
-  if (isNOLINTFound("NOLINTNEXTLINE", CheckName, PrevLine))
-    return true;
-
-  // Check if this line is within a NOLINT(BEGIN...END) block.
-  return EnableNolintBlocks &&
-         lineIsWithinNolintBegin(Context, SuppressionErrors, SM, Loc, CheckName,
-                                 TextBeforeDiag, TextAfterDiag);
-}
-
-static bool lineIsMarkedWithNOLINTinMacro(
-    const Diagnostic &Info, const ClangTidyContext &Context,
-    SmallVectorImpl<ClangTidyError> &SuppressionErrors, bool AllowIO,
-    bool EnableNolintBlocks) {
-  const SourceManager &SM = Info.getSourceManager();
-  SourceLocation Loc = Info.getLocation();
-  std::string CheckName = Context.getCheckName(Info.getID());
-  while (true) {
-    if (lineIsMarkedWithNOLINT(Context, SuppressionErrors, AllowIO, SM, Loc,
-                               CheckName, EnableNolintBlocks))
-      return true;
-    if (!Loc.isMacroID())
-      return false;
-    Loc = SM.getImmediateExpansionRange(Loc).getBegin();
-  }
-  return false;
-}
-
 namespace clang {
 namespace tidy {
 
-bool shouldSuppressDiagnostic(
-    DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info,
-    ClangTidyContext &Context,
-    SmallVectorImpl<ClangTidyError> &SuppressionErrors, bool AllowIO,
-    bool EnableNolintBlocks) {
-  return Info.getLocation().isValid() &&
-         DiagLevel != DiagnosticsEngine::Error &&
-         DiagLevel != DiagnosticsEngine::Fatal &&
-         lineIsMarkedWithNOLINTinMacro(Info, Context, SuppressionErrors,
-                                       AllowIO, EnableNolintBlocks);
-}
-
 const llvm::StringMap<tooling::Replacements> *
 getFixIt(const tooling::Diagnostic &Diagnostic, bool GetFixFromNotes) {
   if (!Diagnostic.Message.Fix.empty())
@@ -545,12 +346,15 @@ void ClangTidyDiagnosticConsumer::HandleDiagnostic(
   if (LastErrorWasIgnored && DiagLevel == DiagnosticsEngine::Note)
     return;
 
-  SmallVector<ClangTidyError, 1> SuppressionErrors;
-  if (shouldSuppressDiagnostic(DiagLevel, Info, Context, SuppressionErrors,
-                               EnableNolintBlocks)) {
+  SmallVector<tooling::Diagnostic, 1> SuppressionErrors;
+  if (Context.shouldSuppressDiagnostic(DiagLevel, Info, SuppressionErrors,
+                                       EnableNolintBlocks)) {
     ++Context.Stats.ErrorsIgnoredNOLINT;
     // Ignored a warning, should ignore related notes as well
     LastErrorWasIgnored = true;
+    Context.DiagEngine->Clear();
+    for (const auto &Error : SuppressionErrors)
+      Context.diag(Error);
     return;
   }
 

clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.h

@@ -11,6 +11,7 @@
 
 #include "ClangTidyOptions.h"
 #include "ClangTidyProfiling.h"
+#include "NoLintDirectiveHandler.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Tooling/Core/Diagnostic.h"
 #include "llvm/ADT/DenseMap.h"
@@ -95,13 +96,33 @@ class ClangTidyContext {
   DiagnosticBuilder diag(StringRef CheckName, StringRef Message,
                          DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
 
-  DiagnosticBuilder diag(const ClangTidyError &Error);
+  DiagnosticBuilder diag(const tooling::Diagnostic &Error);
 
   /// Report any errors to do with reading the configuration using this method.
   DiagnosticBuilder
   configurationDiag(StringRef Message,
                     DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
 
+  /// Check whether a given diagnostic should be suppressed due to the presence
+  /// of a "NOLINT" suppression comment.
+  /// This is exposed so that other tools that present clang-tidy diagnostics
+  /// (such as clangd) can respect the same suppression rules as clang-tidy.
+  /// This does not handle suppression of notes following a suppressed
+  /// diagnostic; that is left to the caller as it requires maintaining state in
+  /// between calls to this function.
+  /// If any NOLINT is malformed, e.g. a BEGIN without a subsequent END, an
+  /// error about it will be returned in output \param NoLintErrors.
+  /// If \param AllowIO is false, the function does not attempt to read source
+  /// files from disk which are not already mapped into memory; such files are
+  /// treated as not containing a suppression comment.
+  /// \param EnableNoLintBlocks controls whether to honor NOLINTBEGIN/NOLINTEND
+  /// blocks; if false, only considers line-level disabling.
+  bool
+  shouldSuppressDiagnostic(DiagnosticsEngine::Level DiagLevel,
+                           const Diagnostic &Info,
+                           SmallVectorImpl<tooling::Diagnostic> &NoLintErrors,
+                           bool AllowIO = true, bool EnableNoLintBlocks = true);
+
   /// Sets the \c SourceManager of the used \c DiagnosticsEngine.
   ///
   /// This is called from the \c ClangTidyCheck base class.
@@ -208,29 +229,9 @@ class ClangTidyContext {
   std::string ProfilePrefix;
 
   bool AllowEnablingAnalyzerAlphaCheckers;
-};
 
-/// Check whether a given diagnostic should be suppressed due to the presence
-/// of a "NOLINT" suppression comment.
-/// This is exposed so that other tools that present clang-tidy diagnostics
-/// (such as clangd) can respect the same suppression rules as clang-tidy.
-/// This does not handle suppression of notes following a suppressed diagnostic;
-/// that is left to the caller as it requires maintaining state in between calls
-/// to this function.
-/// If `AllowIO` is false, the function does not attempt to read source files
-/// from disk which are not already mapped into memory; such files are treated
-/// as not containing a suppression comment.
-/// \param EnableNolintBlocks controls whether to honor NOLINTBEGIN/NOLINTEND
-/// blocks; if false, only considers line-level disabling.
-/// If suppression is not possible due to improper use of "NOLINT" comments -
-/// for example, the use of a "NOLINTBEGIN" comment that is not followed by a
-/// "NOLINTEND" comment - a diagnostic regarding the improper use is returned
-/// via the output argument `SuppressionErrors`.
-bool shouldSuppressDiagnostic(
-    DiagnosticsEngine::Level DiagLevel, const Diagnostic &Info,
-    ClangTidyContext &Context,
-    SmallVectorImpl<ClangTidyError> &SuppressionErrors, bool AllowIO = true,
-    bool EnableNolintBlocks = true);
+  NoLintDirectiveHandler NoLintHandler;
+};
 
 /// Gets the Fix attached to \p Diagnostic.
 /// If there isn't a Fix attached to the diagnostic and \p AnyFix is true, Check