Don't warn for "if ((a == b))" if the parens came from a macro. Thanks to Fariborz for the hint!

llvm-svn: 124689

clang/lib/Sema/SemaExpr.cpp

@@ -9228,6 +9228,11 @@ void Sema::DiagnoseAssignmentAsCondition(Expr *E) {
 /// \brief Redundant parentheses over an equality comparison can indicate
 /// that the user intended an assignment used as condition.
 void Sema::DiagnoseEqualityWithExtraParens(ParenExpr *parenE) {
+  // Don't warn if the parens came from a macro.
+  SourceLocation parenLoc = parenE->getLocStart();
+  if (parenLoc.isInvalid() || parenLoc.isMacroID())
+    return;
+
   Expr *E = parenE->IgnoreParens();
 
   if (BinaryOperator *opE = dyn_cast<BinaryOperator>(E))

clang/test/SemaCXX/warn-assignment-condition.cpp

@@ -110,6 +110,10 @@ void test() {
                    // expected-note {{use '=' to turn this equality comparison into an assignment}} \
                    // expected-note {{remove extraneous parentheses around the comparison to silence this warning}}
   if ((5 == x)) {}
+
+#define EQ(x,y) ((x) == (y))
+  if (EQ(x, 5)) {}
+#undef EQ
 }
 
 void (*fn)();