[C++ Patch] PR 71440 ("ICE on invalid C++ code in instantiate_type, at cp/class.c...")

[Paolo Carlini]

Hi,

by and large this issue seems already fixed in mainline, ie, we don't 
ICE anymore during error recovery, but I noticed that we try to 
prettyprint constructor and destructor as expressions and we end up with 
ugliness like:

error: taking address of constructor ‘((C<int>*)this)->*A::__ct ’

thus the below, tested x86_64-linux. Ok?

Thanks,
Paolo.

////////////////////
/cp
2017-08-02  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/71440
        * typeck.c (build_x_unary_op): Avoid pretty-printing constructor /
        destructor as expressions.

/testsuite
2017-08-02  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/71440
        * g++.dg/template/crash127.C: New.
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 250787)
+++ cp/typeck.c (working copy)
@@ -5487,9 +5487,9 @@ build_x_unary_op (location_t loc, enum tree_code c
            {
              if (complain & tf_error)
                error (DECL_CONSTRUCTOR_P (fn)
-                      ? G_("taking address of constructor %qE")
-                      : G_("taking address of destructor %qE"),
-                      xarg.get_value ());
+                      ? G_("taking address of constructor %qD")
+                      : G_("taking address of destructor %qD"),
+                      fn);
              return error_mark_node;
            }
        }
Index: testsuite/g++.dg/template/crash127.C
===================================================================
--- testsuite/g++.dg/template/crash127.C        (revision 0)
+++ testsuite/g++.dg/template/crash127.C        (working copy)
@@ -0,0 +1,22 @@
+// PR c++/71440
+
+struct A 
+{
+  void f () {}
+};
+
+typedef void (A::*Ptr) ();
+
+template < Ptr > struct B {};
+
+template < class T > 
+struct C : public A
+{
+  void bar ()
+  {
+    B < &A::A > b;  // { dg-error "taking address of constructor 'A::A" "" { 
target c++98_only } }
+    // { dg-error "taking address of constructor 'constexpr A::A" "" { target 
c++11 } .-1 }
+  }
+};
+
+template class C < int >;