1 files changed, 33 insertions, 0 deletions
diff --git a/lib/Lex/Preprocessor.cpp b/lib/Lex/Preprocessor.cpp
index 872cda390a..a0fc265b6b 100644
--- a/lib/Lex/Preprocessor.cpp
+++ b/lib/Lex/Preprocessor.cpp
@@ -285,6 +285,39 @@ Preprocessor::macro_end(bool IncludeExternalMacros) const {
   return Macros.end();
 }
 
+/// \brief Compares macro tokens with a specified token value sequence.
+static bool MacroDefinitionEquals(const MacroInfo *MI,
+                                  llvm::ArrayRef<TokenValue> Tokens) {
+  return Tokens.size() == MI->getNumTokens() &&
+      std::equal(Tokens.begin(), Tokens.end(), MI->tokens_begin());
+}
+
+StringRef Preprocessor::getLastMacroWithSpelling(
+                                    SourceLocation Loc,
+                                    ArrayRef<TokenValue> Tokens) const {
+  SourceLocation BestLocation;
+  StringRef BestSpelling;
+  for (Preprocessor::macro_iterator I = macro_begin(), E = macro_end();
+       I != E; ++I) {
+    if (!I->second->isObjectLike())
+      continue;
+    const MacroInfo *MI = I->second->findDefinitionAtLoc(Loc, SourceMgr);
+    if (!MI)
+      continue;
+    if (!MacroDefinitionEquals(MI, Tokens))
+      continue;
+    SourceLocation Location = I->second->getDefinitionLoc();
+    // Choose the macro defined latest.
+    if (BestLocation.isInvalid() ||
+        (Location.isValid() &&
+         SourceMgr.isBeforeInTranslationUnit(BestLocation, Location))) {
+      BestLocation = Location;
+      BestSpelling = I->first->getName();
+    }
+  }
+  return BestSpelling;
+}
+
 void Preprocessor::recomputeCurLexerKind() {
   if (CurLexer)
     CurLexerKind = CLK_Lexer;