From: Eli Friedman <eli.friedman@gmail.com>
Date: Mon, 25 May 2009 19:41:42 +0000 (+0000)
Subject: PR4122: Tweak the ambiguity handling to handle (S())() correctly.  I've
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b53f08ac87f1e1f4bc2fbfa4560c2183a82020ee;p=clang

PR4122: Tweak the ambiguity handling to handle (S())() correctly.  I've
left out handling for stuff like (S())++ for the moment.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72394 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 5e6ba68067..681c6adb2e 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -1088,12 +1088,17 @@ Parser::ParseCXXAmbiguousParenExpression(ParenParseOption &ExprType,
     ParseAs = CompoundLiteral;
   } else {
     bool NotCastExpr;
-    // Try parsing the cast-expression that may follow.
-    // If it is not a cast-expression, NotCastExpr will be true and no token
-    // will be consumed.
-    Result = ParseCastExpression(false/*isUnaryExpression*/,
-                                 false/*isAddressofOperand*/,
-                                 NotCastExpr);
+    // FIXME: Special-case ++ and --: "(S())++;" is not a cast-expression
+    if (Tok.is(tok::l_paren) && NextToken().is(tok::r_paren)) {
+      NotCastExpr = true;
+    } else {
+      // Try parsing the cast-expression that may follow.
+      // If it is not a cast-expression, NotCastExpr will be true and no token
+      // will be consumed.
+      Result = ParseCastExpression(false/*isUnaryExpression*/,
+                                   false/*isAddressofOperand*/,
+                                   NotCastExpr);
+    }
 
     // If we parsed a cast-expression, it's really a type-id, otherwise it's
     // an expression.
diff --git a/test/Parser/cxx-ambig-paren-expr.cpp b/test/Parser/cxx-ambig-paren-expr.cpp
index 0069561256..6f23b35d3e 100644
--- a/test/Parser/cxx-ambig-paren-expr.cpp
+++ b/test/Parser/cxx-ambig-paren-expr.cpp
@@ -16,4 +16,11 @@ void f() {
   typedef int *PT;
   // Make sure stuff inside the parens are parsed only once (only one warning).
   x = (PT()[(int){1}]); // expected-warning {{compound literals}}
+
+  // Special case: empty parens is a call, not an expression
+  struct S{int operator()();};
+  (S())();
+
+  // FIXME: Special case: "++" is postfix here, not prefix
+  // (S())++;
 }