[Bug c++/14008] New: Confusing diagnostic when ommitting a template parameter

[Bug c++/14008] New: Confusing diagnostic when ommitting a template parameter

[reichelt at gcc dot gnu dot org]

Here are two invalid code snippets where gcc gives misleading diagnostic:

=================================================
namespace N
{ 
    template<int> struct A {};
}

struct B
{
    N::A a;
};
=================================================

With mainline I get

bug1.cc:8: error: using-declaration for non-member at class scope
bug1.cc:8: error: expected `;' before "a"

but I fail to see a using declaration in the code.


If I write "typename N::A a;" instead and make "struct B" a template
like so

=================================================
namespace N
{ 
    template<int> struct A {};
}

template<int> struct B
{
    typename N::A a;
};
=================================================

I get

bug2.cc:8: error: no class template named `A' in `N'
bug2.cc:8: error: ISO C++ forbids declaration of `a' with no type

which is equally confusing, since 'A' *is* a class template in 'N'.

-- 
           Summary: Confusing diagnostic when ommitting a template parameter
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: reichelt at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-03 20:33 -------
3.3.3 gives better diagnostic for the first case:
pr14008.cc:8: error: invalid use of template-name 'N::A' in a declarator
pr14008.cc:8: error: syntax error before `;' token

The second case is not a regression, it is accepted by 3.3.3.

Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-02-03 20:33:51
               date|                            |
            Summary|Confusing diagnostic when   |[3.4/3.5 Regression]
                   |ommitting a template        |Confusing diagnostic when
                   |parameter                   |ommitting a template
                   |                            |parameter
   Target Milestone|---                         |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-04 03:25 -------
Mine, I have a patch almost ready for this.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |giovannibajo at libero dot
                   |dot org                     |it
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-05 01:17 -------
Patch here:
http://gcc.gnu.org/ml/gcc-patches/2004-02/msg00361.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-02-05 07:07 -------
Too risky for 3.4 according to Mark, see 
http://gcc.gnu.org/ml/gcc-patches/2004-02/msg00381.html 
Perhaps it can be backported from mainline in the future. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4.0                       |3.4.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-02-05 16:49 -------
Subject: Bug 14008

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	giovannibajo@gcc.gnu.org	2004-02-05 16:48:55

Modified files:
	gcc/cp         : ChangeLog parser.c 

Log message:
	PR c++/14008
	* parser.c (cp_parser_diagnose_invalid_typename): Removed parsing
	code, only emits the diagnostic now. Added lookup of the identifier
	and support for qualified ids.
	(cp_parser_parse_and_diagnose_invalid_type_name): New function.
	Parse an (invalid) type name as id-expression within a declarator.
	(cp_parser_simple_declaration): Use it.
	(cp_parser_member_declaration): Likewise.
	(cp_parser_make_typename_type): New function. Handle errors through
	cp_parser_diagnose_invalid_typename.
	(cp_parser_elaborated_type_specifier): Use it.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.3937&r2=1.3938
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/parser.c.diff?cvsroot=gcc&r1=1.168&r2=1.169



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-02-05 16:51 -------
Subject: Bug 14008

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	giovannibajo@gcc.gnu.org	2004-02-05 16:50:57

Modified files:
	gcc/testsuite  : ChangeLog 
	gcc/testsuite/g++.dg/parse: crash11.C 
Added files:
	gcc/testsuite/g++.dg/parse: error15.C 

Log message:
	PR c++/14008
	* g++.dg/parse/error15.C: New test.
	* g++.dg/parse/crash11.C: Update dg-error mark.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.3472&r2=1.3473
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/parse/error15.C.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/parse/crash11.C.diff?cvsroot=gcc&r1=1.2&r2=1.3



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4/3.5 Regression] Confusing diagnostic when ommitting a template parameter

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-05 16:55 -------
Fixed in 3.5.0.

It looks like the only 3.4 regression is the wrong message about the using 
declaration. The point is that the parser thinks that N::A is an access-
declaration and in fact then expectes a ";" before "a". Now, if I changed the 
wording to something like:

error: access-declaration for non-member "N::A" at class scope. 

would it be still a regression? Of course it's much inferior than what we get 
in 3.5.0, but it would be a non-intrusive patch.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008

[Bug c++/14008] [3.4 Regression] Confusing diagnostic when omitting a template parameter

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-06-12 21:49 -------
Let's not bother with this for 3.4.x.

Fixed in 3.5.0.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|3.4.1                       |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14008