[Patch/RFC] PR 51216

[Paolo Carlini]

Hi,

is this the right place to handle these TREE_CODEs and avoid the ICEs on 
invalid or should we do something else/earlier?

(tested x86_64-linux)

Thanks,
Paolo.

///////////////////
Index: testsuite/g++.dg/cpp0x/pr51216.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr51216.C    (revision 0)
+++ testsuite/g++.dg/cpp0x/pr51216.C    (revision 0)
@@ -0,0 +1,10 @@
+// PR c++/51216
+// { dg-options "-std=c++0x" }
+
+void foo()
+{
+  int i = ({ if (1) ; });           // { dg-error "ignored" }
+  int j = ({ for (;;) ; });         // { dg-error "ignored" }
+  int k = ({ while (1) ; });        // { dg-error "ignored" }
+  int l = ({ do { } while (1); });  // { dg-error "ignored" }
+}
Index: cp/semantics.c
===================================================================
--- cp/semantics.c      (revision 181494)
+++ cp/semantics.c      (working copy)
@@ -8178,6 +8178,10 @@ potential_constant_expression_1 (tree t, bool want
     case EXPR_STMT:
     case BIND_EXPR:
     case TRANSACTION_EXPR:
+    case IF_STMT:
+    case DO_STMT:
+    case FOR_STMT:
+    case WHILE_STMT:
       if (flags & tf_error)
         error ("expression %qE is not a constant-expression", t);
       return false;