[C++ PATCH] [PR7841] Fix invalid name of constructor

["Giovanni Bajo" <giovannibajo at libero dot it>]

Hello,

the testcase presented in PR 7841 is invalid but accepted by GCC:

-----------------------------------------
template <int dim> class X { X(); };
template <int dim> X<dim>::X<dim> () {};
----------------------------^^^^^--------

In fact, the constructor is not a template, and the template argument list can
be specified only after template names (14.2/2). Notice also that X cannot be
the injected class name (in template form) because it is qualified (14.6.1/1).
The following patch detects and rejects this code in the parser. The error
message which the patch adds is:

pr7841.cc: At global scope:
pr7841.cc:2: error: invalid use of argument list for a constructor in a
qualified name
pr7841.cc:2: note: use `X<dim>::X' instead of `X<dim>::X<dim>' to name the
constructor in a qualified name

There was already a test in old-deja that was testing for this construct as
valid (it's probably pre-ISO), so I just added a dg-error mark to it.

Tested on i686-pc-linux-gnu, OK for mainline?

Giovanni Bajo


cp/
2004-04-19  Giovanni Bajo  <giovannibajo@gcc.gnu.org>

        PR c++/7841
        * parser.c (cp_parser_direct_declarator): Reject constructor named
        as qualified template-id.

testsuite/
2004-04-19  Giovanni Bajo  <giovannibajo@gcc.gnu.org>

        PR c++/7841
        * g++.old-deja/g++.pt/ctor2.C: Add error mark.


Index: cp/parser.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/parser.c,v
retrieving revision 1.188
diff -c -3 -p -r1.188 parser.c
*** cp/parser.c 30 Mar 2004 19:19:01 -0000 1.188
--- cp/parser.c 19 Apr 2004 20:55:26 -0000
*************** cp_parser_direct_declarator (cp_parser*
*** 10633,10638 ****
--- 10633,10649 ----
          && same_type_p (TREE_TYPE (unqualified_name),
            class_type)))
    *ctor_dtor_or_conv_p = -1;
+   if (TREE_CODE (declarator) == SCOPE_REF
+       && TREE_CODE (unqualified_name) == TYPE_DECL
+       && CLASSTYPE_USE_TEMPLATE (TREE_TYPE (unqualified_name)))
+     {
+       error ("invalid use of argument list for a constructor "
+              "in a qualified name");
+       inform ("use `%T::%D' instead of `%T::%T' to name the "
+        "constructor in a qualified name", class_type,
+        DECL_NAME (TYPE_TI_TEMPLATE (class_type)),
+        class_type, class_type);
+     }
       }

   handle_declarator:;
Index: testsuite/g++.old-deja/g++.pt/ctor2.C
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C,v
retrieving revision 1.3
diff -c -3 -p -r1.3 ctor2.C
*** testsuite/g++.old-deja/g++.pt/ctor2.C 1 May 2003 02:02:53 -0000 1.3
--- testsuite/g++.old-deja/g++.pt/ctor2.C 19 Apr 2004 20:55:26 -0000
*************** struct A {
*** 8,13 ****
  };

  template <class T>
! A<T>::A<T>()
  {
  }
--- 8,13 ----
  };

  template <class T>
! A<T>::A<T>()   // { dg-error "invalid use of argument list|qualified name" }
  {
  }