[Lexer] Report more precise skipped regions (PR34166)

[vsk]

Summary

This patch teaches the preprocessor to report more precise source ranges for code that is skipped due to conditional directives.

The new behavior includes the '#' from the opening directive and the full text of the line containing the closing directive in the skipped area. This matches up clang's behavior (we don't IRGen the code between the closing "endif" and the end of a line).

This also affects the code coverage implementation. See llvm.org/PR34166 (this also happens to be rdar://problem/23224058).

[efriedma]

I'm not sure this produces the right locations in general. Consider the following slightly evil testcase:

#\
if 0
#elif \
11\

int a;
#endif

[vsk]

Thanks for the review. I've updated the patch so that we do better with "#\" directives.

[efriedma]

lib/Lex/PPDirectives.cpp

569

This doesn't really handle backslash-escaped newlines correctly. (Not likely to matter, I guess, but better to get it right while we're messing with it.)

Could we use CurPPLexer->getSourceLocation() or something like that, instead of trying to scan the line ourselves?

[vsk]

• Address Eli's comment.

lib/Lex/PPDirectives.cpp

569

Thanks again for the catch! CurPPLexer->getSourceLocation() does the job. I couldn't find an efficient solution which places the end of the skipped range at the end of the line containing the #endif. With getSourceLocation(), we always set the end location to the first column of the line after the #endif. I think this is OK (at least, it shouldn't affect coverage rendering).

[efriedma]

I'd like to see someone more familiar with indexing comment on the effect there; otherwise LGTM.

[arphaman]

lib/Lex/PPDirectives.cpp

564

You'd have to update the pp-tests in clang-tools-extra too

test/Index/skipped-ranges.c

23–25

Some editor clients might want to grey out the skipped PP ranges. The new end location is not ideal as we wouldn't want to grey out the trailing comments after the #endif.

[vsk]

test/Index/skipped-ranges.c

23–25

It seems like the end location we want should be different for the coverage client and the indexer. I'll modify the callback so we pass along both end locations.

[vsk]

• Add an 'EndifLoc' parameter to the SourceRangeSkipped callback so that indexing clients can preserve their existing behavior.
• I'll submit a follow-up patch which updates the pp-trace tests.

[arphaman]

Thanks, LGTM

include/clang/Lex/PPCallbacks.h

public:
   /// \param MD The MacroDirective if the name was a macro, null otherwise.
   virtual void Defined(const Token &MacroNameTok, const MacroDefinition &MD,
                        SourceRange Range) {
   }
   
   /// \brief Hook called when a source range is skipped.
   /// \param Range The SourceRange that was skipped. The range begins at the
   /// \#if/\#else directive and ends after the \#endif/\#else directive.
-  virtual void SourceRangeSkipped(SourceRange Range) {
+  /// \param EndifLoc The end location of the 'endif' token, which may precede
+  /// the range skipped by the directive (e.g excluding comments after an
+  /// 'endif').
+  virtual void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) {
   }
 
   enum ConditionValueKind {
     CVK_NotEvaluated, CVK_False, CVK_True
   };
 
   /// \brief Hook called whenever an \#if is seen.
   /// \param Loc the source location of the directive.
public:
   }
 
   void Defined(const Token &MacroNameTok, const MacroDefinition &MD,
                SourceRange Range) override {
     First->Defined(MacroNameTok, MD, Range);
     Second->Defined(MacroNameTok, MD, Range);
   }
 
-  void SourceRangeSkipped(SourceRange Range) override {
-    First->SourceRangeSkipped(Range);
-    Second->SourceRangeSkipped(Range);
+  void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override {
+    First->SourceRangeSkipped(Range, EndifLoc);
+    Second->SourceRangeSkipped(Range, EndifLoc);
   }
 
   /// \brief Hook called whenever an \#if is seen.
   void If(SourceLocation Loc, SourceRange ConditionRange,
           ConditionValueKind ConditionValue) override {
     First->If(Loc, ConditionRange, ConditionValue);
     Second->If(Loc, ConditionRange, ConditionValue);
   }

include/clang/Lex/PreprocessingRecord.h

private:
     void Ifdef(SourceLocation Loc, const Token &MacroNameTok,
                const MacroDefinition &MD) override;
     void Ifndef(SourceLocation Loc, const Token &MacroNameTok,
                 const MacroDefinition &MD) override;
     /// \brief Hook called whenever the 'defined' operator is seen.
     void Defined(const Token &MacroNameTok, const MacroDefinition &MD,
                  SourceRange Range) override;
 
-    void SourceRangeSkipped(SourceRange Range) override;
+    void SourceRangeSkipped(SourceRange Range,
+                            SourceLocation EndifLoc) override;
 
     void addMacroExpansion(const Token &Id, const MacroInfo *MI,
                            SourceRange Range);
 
     /// \brief Cached result of the last \see getPreprocessedEntitiesInRange
     /// query.
     struct {
       SourceRange Range;

include/clang/Lex/Preprocessor.h

   /// We just read a \#if or related directive and decided that the
   /// subsequent tokens are in the \#if'd out portion of the
   /// file.  Lex the rest of the file, until we see an \#endif.  If \p
   /// FoundNonSkipPortion is true, then we have already emitted code for part of
   /// this \#if directive, so \#else/\#elif blocks should never be entered. If
   /// \p FoundElse is false, then \#else directives are ok, if not, then we have
   /// already seen one so a \#else directive is a duplicate.  When this returns,
   /// the caller can lex the first valid token.
-  void SkipExcludedConditionalBlock(SourceLocation IfTokenLoc,
+  void SkipExcludedConditionalBlock(const Token &HashToken,
+                                    SourceLocation IfTokenLoc,
                                     bool FoundNonSkipPortion, bool FoundElse,
                                     SourceLocation ElseLoc = SourceLocation());
 
   /// \brief A fast PTH version of SkipExcludedConditionalBlock.
   void PTHSkipExcludedConditionalBlock();
 
   /// Information about the result for evaluating an expression for a
   /// preprocessor directive.

   /// the preamble.
   void replayPreambleConditionalStack();
 
   // Macro handling.
   void HandleDefineDirective(Token &Tok, bool ImmediatelyAfterTopLevelIfndef);
   void HandleUndefDirective();
 
   // Conditional Inclusion.
-  void HandleIfdefDirective(Token &Tok, bool isIfndef,
-                            bool ReadAnyTokensBeforeDirective);
-  void HandleIfDirective(Token &Tok, bool ReadAnyTokensBeforeDirective);
+  void HandleIfdefDirective(Token &Tok, const Token &HashToken,
+                            bool isIfndef, bool ReadAnyTokensBeforeDirective);
+  void HandleIfDirective(Token &Tok, const Token &HashToken,
+                         bool ReadAnyTokensBeforeDirective);
   void HandleEndifDirective(Token &Tok);
-  void HandleElseDirective(Token &Tok);
-  void HandleElifDirective(Token &Tok);
+  void HandleElseDirective(Token &Tok, const Token &HashToken);
+  void HandleElifDirective(Token &Tok, const Token &HashToken);
 
   // Pragmas.
   void HandlePragmaDirective(SourceLocation IntroducerLoc,
                              PragmaIntroducerKind Introducer);
 public:
   void HandlePragmaOnce(Token &OnceTok);
   void HandlePragmaMark();
   void HandlePragmaPoison();

lib/CodeGen/CoverageMappingGen.h

 /// \brief Stores additional source code information like skipped ranges which
 /// is required by the coverage mapping generator and is obtained from
 /// the preprocessor.
 class CoverageSourceInfo : public PPCallbacks {
   std::vector<SourceRange> SkippedRanges;
 public:
   ArrayRef<SourceRange> getSkippedRanges() const { return SkippedRanges; }
 
-  void SourceRangeSkipped(SourceRange Range) override;
+  void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override;
 };
 
 namespace CodeGen {
 
 class CodeGenModule;
 
 /// \brief Organizes the cross-function state that is used while generating
 /// code coverage mapping data.

lib/CodeGen/CoverageMappingGen.cpp

 #include "llvm/ProfileData/InstrProfReader.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 
 using namespace clang;
 using namespace CodeGen;
 using namespace llvm::coverage;
 
-void CoverageSourceInfo::SourceRangeSkipped(SourceRange Range) {
+void CoverageSourceInfo::SourceRangeSkipped(SourceRange Range, SourceLocation) {
   SkippedRanges.push_back(Range);
 }
 
 namespace {
 
 /// \brief A region of source code that can be mapped to a counter.
 class SourceMappingRegion {
   Counter Count;

lib/Lex/PPDirectives.cpp

 
 VisibilityMacroDirective *
 Preprocessor::AllocateVisibilityMacroDirective(SourceLocation Loc,
                                                bool isPublic) {
   return new (BP) VisibilityMacroDirective(Loc, isPublic);
 }
 
 /// \brief Read and discard all tokens remaining on the current line until
-/// the tok::eod token is found.
+/// the tok::eod token is found. If the discarded tokens are in a skipped range,
+/// complete the range and pass it to the \c SourceRangeSkipped callback.
 void Preprocessor::DiscardUntilEndOfDirective() {
   Token Tmp;
   do {
     LexUnexpandedToken(Tmp);
     assert(Tmp.isNot(tok::eof) && "EOF seen while discarding directive tokens");
   } while (Tmp.isNot(tok::eod));
 }
 

 /// SkipExcludedConditionalBlock - We just read a \#if or related directive and
 /// decided that the subsequent tokens are in the \#if'd out portion of the
 /// file.  Lex the rest of the file, until we see an \#endif.  If
 /// FoundNonSkipPortion is true, then we have already emitted code for part of
 /// this \#if directive, so \#else/\#elif blocks should never be entered.
 /// If ElseOk is true, then \#else directives are ok, if not, then we have
 /// already seen one so a \#else directive is a duplicate.  When this returns,
 /// the caller can lex the first valid token.
-void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc,
+void Preprocessor::SkipExcludedConditionalBlock(const Token &HashToken,
+                                                SourceLocation IfTokenLoc,
                                                 bool FoundNonSkipPortion,
                                                 bool FoundElse,
                                                 SourceLocation ElseLoc) {
   ++NumSkipped;
   assert(!CurTokenLexer && CurPPLexer && "Lexing a macro, not a file?");
 
   CurPPLexer->pushConditionalLevel(IfTokenLoc, /*isSkipping*/false,
                                  FoundNonSkipPortion, FoundElse);
while (true) {
     if (CurLexer) CurLexer->resetExtendedTokenMode();
   }
 
   // Finally, if we are out of the conditional (saw an #endif or ran off the end
   // of the file, just stop skipping and return to lexing whatever came after
   // the #if block.
   CurPPLexer->LexingRawMode = false;
 
-  if (Callbacks) {
-    SourceLocation BeginLoc = ElseLoc.isValid() ? ElseLoc : IfTokenLoc;
-    Callbacks->SourceRangeSkipped(SourceRange(BeginLoc, Tok.getLocation()));
-  }
+  if (Callbacks)
+    Callbacks->SourceRangeSkipped(
+        SourceRange(HashToken.getLocation(), CurPPLexer->getSourceLocation()),
+        Tok.getLocation());
 }
 
 void Preprocessor::PTHSkipExcludedConditionalBlock() {
   while (true) {
     assert(CurPTHLexer);
     assert(CurPTHLexer->LexingRawMode == false);
 
     // Skip to the next '#else', '#elif', or #endif.
     if (CurPTHLexer->SkipBlock()) {
       // We have reached an #endif.  Both the '#' and 'endif' tokens
       // have been consumed by the PTHLexer.  Just pop off the condition level.
default:
     IdentifierInfo *II = Result.getIdentifierInfo();
     if (!II) break; // Not an identifier.
 
     // Ask what the preprocessor keyword ID is.
     switch (II->getPPKeywordID()) {
     default: break;
     // C99 6.10.1 - Conditional Inclusion.
     case tok::pp_if:
-      return HandleIfDirective(Result, ReadAnyTokensBeforeDirective);
+      return HandleIfDirective(Result, SavedHash, ReadAnyTokensBeforeDirective);
     case tok::pp_ifdef:
-      return HandleIfdefDirective(Result, false, true/*not valid for miopt*/);
+      return HandleIfdefDirective(Result, SavedHash, false,
+                                  true /*not valid for miopt*/);
     case tok::pp_ifndef:
-      return HandleIfdefDirective(Result, true, ReadAnyTokensBeforeDirective);
+      return HandleIfdefDirective(Result, SavedHash, true,
+                                  ReadAnyTokensBeforeDirective);
     case tok::pp_elif:
-      return HandleElifDirective(Result);
+      return HandleElifDirective(Result, SavedHash);
     case tok::pp_else:
-      return HandleElseDirective(Result);
+      return HandleElseDirective(Result, SavedHash);
     case tok::pp_endif:
       return HandleEndifDirective(Result);
 
     // C99 6.10.2 - Source File Inclusion.
     case tok::pp_include:
       // Handle #include.
       return HandleIncludeDirective(SavedHash.getLocation(), Result);
     case tok::pp___include_macros:

 // Preprocessor Conditional Directive Handling.
 //===----------------------------------------------------------------------===//
 
 /// HandleIfdefDirective - Implements the \#ifdef/\#ifndef directive.  isIfndef
 /// is true when this is a \#ifndef directive.  ReadAnyTokensBeforeDirective is
 /// true if any tokens have been returned or pp-directives activated before this
 /// \#ifndef has been lexed.
 ///
-void Preprocessor::HandleIfdefDirective(Token &Result, bool isIfndef,
+void Preprocessor::HandleIfdefDirective(Token &Result,
+                                        const Token &HashToken,
+                                        bool isIfndef,
                                         bool ReadAnyTokensBeforeDirective) {
   ++NumIf;
   Token DirectiveTok = Result;
 
   Token MacroNameTok;
   ReadMacroName(MacroNameTok);
 
   // Error reading macro name?  If so, diagnostic already issued.
   if (MacroNameTok.is(tok::eod)) {
     // Skip code until we get to #endif.  This helps with recovery by not
     // emitting an error when the #endif is reached.
-    SkipExcludedConditionalBlock(DirectiveTok.getLocation(),
-                                 /*Foundnonskip*/false, /*FoundElse*/false);
+    SkipExcludedConditionalBlock(HashToken, DirectiveTok.getLocation(),
+                                 /*Foundnonskip*/ false, /*FoundElse*/ false);
     return;
   }
 
   // Check to see if this is the last token on the #if[n]def line.
   CheckEndOfDirective(isIfndef ? "ifndef" : "ifdef");
 
   IdentifierInfo *MII = MacroNameTok.getIdentifierInfo();
   auto MD = getMacroDefinition(MII);
CurPPLexer->pushConditionalLevel(DirectiveTok.getLocation(),
                                      /*foundelse*/false);
   } else if (!MI == isIfndef) {
     // Yes, remember that we are inside a conditional, then lex the next token.
     CurPPLexer->pushConditionalLevel(DirectiveTok.getLocation(),
                                      /*wasskip*/false, /*foundnonskip*/true,
                                      /*foundelse*/false);
   } else {
     // No, skip the contents of this block.
-    SkipExcludedConditionalBlock(DirectiveTok.getLocation(),
-                                 /*Foundnonskip*/false,
-                                 /*FoundElse*/false);
+    SkipExcludedConditionalBlock(HashToken, DirectiveTok.getLocation(),
+                                 /*Foundnonskip*/ false,
+                                 /*FoundElse*/ false);
   }
 }
 
 /// HandleIfDirective - Implements the \#if directive.
 ///
 void Preprocessor::HandleIfDirective(Token &IfToken,
+                                     const Token &HashToken,
                                      bool ReadAnyTokensBeforeDirective) {
   ++NumIf;
 
   // Parse and evaluate the conditional expression.
   IdentifierInfo *IfNDefMacro = nullptr;
   const SourceLocation ConditionalBegin = CurPPLexer->getSourceLocation();
   const DirectiveEvalResult DER = EvaluateDirectiveExpression(IfNDefMacro);
   const bool ConditionalTrue = DER.Conditional;
if (PPOpts->SingleFileParseMode && DER.IncludedUndefinedIds) {
     CurPPLexer->pushConditionalLevel(IfToken.getLocation(), /*wasskip*/false,
                                      /*foundnonskip*/false, /*foundelse*/false);
   } else if (ConditionalTrue) {
     // Yes, remember that we are inside a conditional, then lex the next token.
     CurPPLexer->pushConditionalLevel(IfToken.getLocation(), /*wasskip*/false,
                                    /*foundnonskip*/true, /*foundelse*/false);
   } else {
     // No, skip the contents of this block.
-    SkipExcludedConditionalBlock(IfToken.getLocation(), /*Foundnonskip*/false,
-                                 /*FoundElse*/false);
+    SkipExcludedConditionalBlock(HashToken, IfToken.getLocation(),
+                                 /*Foundnonskip*/ false,
+                                 /*FoundElse*/ false);
   }
 }
 
 /// HandleEndifDirective - Implements the \#endif directive.
 ///
 void Preprocessor::HandleEndifDirective(Token &EndifToken) {
   ++NumEndif;
 
assert(!CondInfo.WasSkipping && !CurPPLexer->LexingRawMode &&
          "This code should only be reachable in the non-skipping case!");
 
   if (Callbacks)
     Callbacks->Endif(EndifToken.getLocation(), CondInfo.IfLoc);
 }
 
 /// HandleElseDirective - Implements the \#else directive.
 ///
-void Preprocessor::HandleElseDirective(Token &Result) {
+void Preprocessor::HandleElseDirective(Token &Result, const Token &HashToken) {
   ++NumElse;
 
   // #else directive in a non-skipping conditional... start skipping.
   CheckEndOfDirective("else");
 
   PPConditionalInfo CI;
   if (CurPPLexer->popConditionalLevel(CI)) {
     Diag(Result, diag::pp_err_else_without_if);
if (PPOpts->SingleFileParseMode && !CI.FoundNonSkip) {
     // In 'single-file-parse mode' undefined identifiers trigger parsing of all
     // the directive blocks.
     CurPPLexer->pushConditionalLevel(CI.IfLoc, /*wasskip*/false,
                                      /*foundnonskip*/false, /*foundelse*/true);
     return;
   }
 
   // Finally, skip the rest of the contents of this block.
-  SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true,
-                               /*FoundElse*/true, Result.getLocation());
+  SkipExcludedConditionalBlock(HashToken, CI.IfLoc, /*Foundnonskip*/ true,
+                               /*FoundElse*/ true, Result.getLocation());
 }
 
 /// HandleElifDirective - Implements the \#elif directive.
 ///
-void Preprocessor::HandleElifDirective(Token &ElifToken) {
+void Preprocessor::HandleElifDirective(Token &ElifToken,
+                                       const Token &HashToken) {
   ++NumElse;
 
   // #elif directive in a non-skipping conditional... start skipping.
   // We don't care what the condition is, because we will always skip it (since
   // the block immediately before it was included).
   const SourceLocation ConditionalBegin = CurPPLexer->getSourceLocation();
   DiscardUntilEndOfDirective();
   const SourceLocation ConditionalEnd = CurPPLexer->getSourceLocation();
if (PPOpts->SingleFileParseMode && !CI.FoundNonSkip) {
     // In 'single-file-parse mode' undefined identifiers trigger parsing of all
     // the directive blocks.
     CurPPLexer->pushConditionalLevel(ElifToken.getLocation(), /*wasskip*/false,
                                      /*foundnonskip*/false, /*foundelse*/false);
     return;
   }
 
   // Finally, skip the rest of the contents of this block.
-  SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true,
-                               /*FoundElse*/CI.FoundElse,
+  SkipExcludedConditionalBlock(HashToken, CI.IfLoc, /*Foundnonskip*/ true,
+                               /*FoundElse*/ CI.FoundElse,
                                ElifToken.getLocation());
 }

lib/Lex/PreprocessingRecord.cpp

void PreprocessingRecord::Defined(const Token &MacroNameTok,
                                   const MacroDefinition &MD,
                                   SourceRange Range) {
   // This is not actually a macro expansion but record it as a macro reference.
   if (MD)
     addMacroExpansion(MacroNameTok, MD.getMacroInfo(),
                       MacroNameTok.getLocation());
 }
 
-void PreprocessingRecord::SourceRangeSkipped(SourceRange Range) {
-  SkippedRanges.push_back(Range);
+void PreprocessingRecord::SourceRangeSkipped(SourceRange Range,
+                                             SourceLocation EndifLoc) {
+  SkippedRanges.emplace_back(Range.getBegin(), EndifLoc);
 }
 
 void PreprocessingRecord::MacroExpands(const Token &Id,
                                        const MacroDefinition &MD,
                                        SourceRange Range,
                                        const MacroArgs *Args) {
   addMacroExpansion(Id, MD.getMacroInfo(), Range);
 }

test/CoverageMapping/preprocessor.c

 // RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -main-file-name preprocessor.c %s | FileCheck %s
 
                  // CHECK: func
 void func() {    // CHECK: File 0, [[@LINE]]:13 -> [[@LINE+5]]:2 = #0
   int i = 0;
-#ifdef MACRO     // CHECK-NEXT: Skipped,File 0, [[@LINE]]:2 -> [[@LINE+2]]:2 = 0
+#ifdef MACRO     // CHECK-NEXT: Skipped,File 0, [[@LINE]]:1 -> [[@LINE+3]]:1 = 0
   int x = i;
 #endif
 }
 
-#if 0
-  int g = 0;
-
-  void bar() { }
-#endif
-
                  // CHECK: main
 int main() {     // CHECK-NEXT: File 0, [[@LINE]]:12 -> {{[0-9]+}}:2 = #0
   int i = 0;
-#if 0            // CHECK-NEXT: Skipped,File 0, [[@LINE]]:2 -> [[@LINE+4]]:2 = 0
+#  if 0            // CHECK-NEXT: Skipped,File 0, [[@LINE]]:1 -> [[@LINE+5]]:1 = 0
   if(i == 0) {
     i = 1;
   }
-#endif
+#  endif // Mark me skipped!
 
 #if 1
                  // CHECK-NEXT: File 0, [[@LINE+1]]:6 -> [[@LINE+1]]:12 = #0
   if(i == 0) {   // CHECK-NEXT: File 0, [[@LINE]]:14 -> [[@LINE+2]]:4 = #1
     i = 1;
   }
-#else            // CHECK-NEXT: Skipped,File 0, [[@LINE]]:2 -> [[@LINE+5]]:2 = 0
+#else            // CHECK-NEXT: Skipped,File 0, [[@LINE]]:1 -> [[@LINE+6]]:1 = 0
   if(i == 1) {
     i = 0;
   }
 }
 #endif
+
+  // CHECK-NEXT: Skipped,File 0, [[@LINE+1]]:1 -> [[@LINE+5]]:1
+#\
+  if 0
+#\
+  endif // also skipped
+
+#if 1
+  // CHECK-NEXT: Skipped,File 0, [[@LINE+1]]:1 -> [[@LINE+4]]:1
+#\
+  elif 0
+#endif
+
+#if 1
+  // CHECK-NEXT: Skipped,File 0, [[@LINE+1]]:1 -> [[@LINE+4]]:1
+#\
+  else
+#endif
+
+  // CHECK-NEXT: Skipped,File 0, [[@LINE+1]]:1 -> [[@LINE+5]]:1
+#\
+  ifdef NOT_DEFINED
+#\
+  endif
+
+  // CHECK-NEXT: Skipped,File 0, [[@LINE+1]]:1 -> [[@LINE+5]]:1
+#\
+  ifndef __FILE__
+#\
+  endif
+
+  // CHECK-NEXT: Skipped,File 0, [[@LINE+1]]:1 -> [[@LINE+7]]:1
+#\
+  ifdef NOT_DEFINED
+#\
+  \
+   \
+    endif // also skipped
+
   return 0;
 }

test/Index/skipped-ranges.c

 #ifndef uncool
 
 int probably_hot = 1;
 
 #endif // uncool
 #endif // cool
 
 // RUN: env CINDEXTEST_SHOW_SKIPPED_RANGES=1 c-index-test -test-annotate-tokens=%s:1:1:16:1 %s | FileCheck %s
-// CHECK: Skipping: [5:2 - 6:7]
-// CHECK: Skipping: [8:2 - 12:7]
-// CHECK: Skipping: [14:2 - 20:7]
+// CHECK: Skipping: [5:1 - 6:7]
+// CHECK: Skipping: [8:1 - 12:7]
+// CHECK: Skipping: [14:1 - 20:7]

tools/libclang/Indexing.cpp

public:
 
   /// MacroExpands - This is called by when a macro invocation is found.
   void MacroExpands(const Token &MacroNameTok, const MacroDefinition &MD,
                     SourceRange Range, const MacroArgs *Args) override {}
 
   /// SourceRangeSkipped - This hook is called when a source range is skipped.
   /// \param Range The SourceRange that was skipped. The range begins at the
   /// #if/#else directive and ends after the #endif/#else directive.
-  void SourceRangeSkipped(SourceRange Range) override {}
+  void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override {
+  }
 };
 
 //===----------------------------------------------------------------------===//
 // IndexingConsumer
 //===----------------------------------------------------------------------===//
 
 class IndexingConsumer : public ASTConsumer {
   CXIndexDataConsumer &DataConsumer;