Index: clang-tidy/misc/RedundantExpressionCheck.cpp
===================================================================
--- clang-tidy/misc/RedundantExpressionCheck.cpp
+++ clang-tidy/misc/RedundantExpressionCheck.cpp
@@ -132,6 +132,18 @@
   case Stmt::BinaryOperatorClass:
     return cast<BinaryOperator>(Left)->getOpcode() ==
            cast<BinaryOperator>(Right)->getOpcode();
+  case Stmt::UnaryExprOrTypeTraitExprClass:
+    if (cast<UnaryExprOrTypeTraitExpr>(Left)->isArgumentType() &&
+        cast<UnaryExprOrTypeTraitExpr>(Right)->isArgumentType())
+      return cast<UnaryExprOrTypeTraitExpr>(Left)->getArgumentType() ==
+             cast<UnaryExprOrTypeTraitExpr>(Right)->getArgumentType();
+    else if (!cast<UnaryExprOrTypeTraitExpr>(Left)->isArgumentType() &&
+             !cast<UnaryExprOrTypeTraitExpr>(Right)->isArgumentType())
+      return areEquivalentExpr(
+          cast<UnaryExprOrTypeTraitExpr>(Left)->getArgumentExpr(),
+          cast<UnaryExprOrTypeTraitExpr>(Right)->getArgumentExpr());
+
+    return false;
   }
 }
 
@@ -598,23 +610,66 @@
   return true;
 }
 
+static bool isSameToken(Token &T1, Token &T2, const SourceManager &SM) {
+  if (T1.getKind()!=T2.getKind())
+    return false;
+  else if (T1.isNot(tok::raw_identifier))
+    return true;
+  if (T1.getLength() != T2.getLength())
+    return false;
+  return strncmp(SM.getCharacterData(T1.getLocation()),
+                 SM.getCharacterData(T2.getLocation()), T1.getLength()) == 0;
+}
+
+unsigned getCharCountUntilEndOfExpr(SourceRange ExprSR, Token T,
+                                    const SourceManager &SM) {
+  assert((T.getLocation() < ExprSR.getBegin()  ||
+          ExprSR.getEnd() < T.getLocation()) &&
+         "Token is not within the expression range!");
+
+  return SM.getCharacterData(SM.getExpansionLoc(ExprSR.getEnd())) -
+         SM.getCharacterData(T.getLocation());
+}
+
+/// Returns true if both LhsEpxr and RhsExpr are
+/// macro expressions and they are expanded
+/// from different macros.
 static bool areExprsFromDifferentMacros(const Expr *LhsExpr,
                                         const Expr *RhsExpr,
                                         const ASTContext *AstCtx) {
   if (!LhsExpr || !RhsExpr)
     return false;
-
-  SourceLocation LhsLoc = LhsExpr->getExprLoc();
-  SourceLocation RhsLoc = RhsExpr->getExprLoc();
-
-  if (!LhsLoc.isMacroID() || !RhsLoc.isMacroID())
+  SourceRange Lsr = LhsExpr->getSourceRange();
+  SourceRange Rsr = RhsExpr->getSourceRange();
+  if (!Lsr.getBegin().isMacroID() || !Rsr.getBegin().isMacroID())
     return false;
-
   const SourceManager &SM = AstCtx->getSourceManager();
   const LangOptions &LO = AstCtx->getLangOpts();
 
-  return !(Lexer::getImmediateMacroName(LhsLoc, SM, LO) ==
-          Lexer::getImmediateMacroName(RhsLoc, SM, LO));
+  std::pair<FileID, unsigned> LsrLocInfo =
+      SM.getDecomposedLoc(SM.getExpansionLoc(Lsr.getBegin()));
+  std::pair<FileID, unsigned> RsrLocInfo =
+      SM.getDecomposedLoc(SM.getExpansionLoc(Rsr.getBegin()));
+  const llvm::MemoryBuffer *MB = SM.getBuffer(LsrLocInfo.first);
+
+  const char *LTokenPos = MB->getBufferStart() + LsrLocInfo.second;
+  const char *RTokenPos = MB->getBufferStart() + RsrLocInfo.second;
+  Lexer LRawLex(SM.getLocForStartOfFile(LsrLocInfo.first), LO,
+                MB->getBufferStart(), LTokenPos, MB->getBufferEnd());
+  Lexer RRawLex(SM.getLocForStartOfFile(RsrLocInfo.first), LO,
+                MB->getBufferStart(), RTokenPos, MB->getBufferEnd());
+
+  Token LTok, RTok;
+  do { // Compare the expressions token-by-token.
+    LRawLex.LexFromRawLexer(LTok);
+    RRawLex.LexFromRawLexer(RTok);
+  } while (!LTok.is(tok::eof) && !RTok.is(tok::eof) &&
+           isSameToken(LTok, RTok, SM) &&
+           getCharCountUntilEndOfExpr(Lsr, LTok, SM) > 0 &&
+           getCharCountUntilEndOfExpr(Rsr, RTok, SM) > 0);
+  return !((getCharCountUntilEndOfExpr(Lsr, LTok, SM) == 0 &&
+            getCharCountUntilEndOfExpr(Rsr, RTok, SM) == 0) &&
+           isSameToken(LTok, RTok, SM));
 }
 
 static bool areExprsMacroAndNonMacro(const Expr *&LhsExpr,
@@ -993,7 +1048,6 @@
           Result.Nodes.getNodeAs<ConditionalOperator>("cond")) {
     const Expr *TrueExpr = CondOp->getTrueExpr();
     const Expr *FalseExpr = CondOp->getFalseExpr();
-
     if (areExprsFromDifferentMacros(TrueExpr, FalseExpr, Result.Context) ||
         areExprsMacroAndNonMacro(TrueExpr, FalseExpr))
       return;
Index: test/clang-tidy/misc-redundant-expression.cpp
===================================================================
--- test/clang-tidy/misc-redundant-expression.cpp
+++ test/clang-tidy/misc-redundant-expression.cpp
@@ -106,6 +106,7 @@
 
 #define COND_OP_MACRO 9
 #define COND_OP_OTHER_MACRO 9
+#define COND_OP_THIRD_MACRO COND_OP_MACRO
 int TestConditional(int x, int y) {
   int k = 0;
   k += (y < 0) ? x : x;
@@ -114,16 +115,33 @@
   // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: 'true' and 'false' expressions are equivalent
   k += (y < 0) ? COND_OP_MACRO : COND_OP_MACRO;
   // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: 'true' and 'false' expressions are equivalent
+  k += (y < 0) ? COND_OP_MACRO + COND_OP_OTHER_MACRO : COND_OP_MACRO + COND_OP_OTHER_MACRO;
+  // CHECK-MESSAGES: :[[@LINE-1]]:54: warning: 'true' and 'false' expressions are equivalent
 
   // Do not match for conditional operators with a macro and a const.
   k += (y < 0) ? COND_OP_MACRO : 9;
   // Do not match for conditional operators with expressions from different macros.
   k += (y < 0) ? COND_OP_MACRO : COND_OP_OTHER_MACRO;
+  // Do not match for conditional operators when a macro is defined to another macro
+  k += (y < 0) ? COND_OP_MACRO : COND_OP_THIRD_MACRO;
+#undef COND_OP_THIRD_MACRO
+#define   COND_OP_THIRD_MACRO 8
+  k += (y < 0) ? COND_OP_MACRO : COND_OP_THIRD_MACRO;
+#undef COND_OP_THIRD_MACRO
+
+  k += (y < 0) ? sizeof(I64) : sizeof(I64);
+  // CHECK-MESSAGES: :[[@LINE-1]]:30: warning: 'true' and 'false' expressions are equivalent
+  k += (y < 0) ? sizeof(TestConditional(k,y)) : sizeof(TestConditional(k,y));
+  // CHECK-MESSAGES: :[[@LINE-1]]:47: warning: 'true' and 'false' expressions are equivalent
+  // No warning if the expression arguments are different.
+  k += (y < 0) ? sizeof(TestConditional(k,y)) : sizeof(Valid(k,y));
+
   return k;
 }
 #undef COND_OP_MACRO
 #undef COND_OP_OTHER_MACRO
 
+
 // Overloaded operators that compare two instances of a struct.
 struct MyStruct {
   int x;