[Bug c++/47488] New: [C++0x] decltype + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[Bug c++/47488] New: [C++0x] decltype + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[flast at flast dot jp]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

           Summary: [C++0x] decltype + template + string literals: ICE in
                    write_template_arg_literal, at cp/mangle.c
           Product: gcc
           Version: 4.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: flast@flast.jp


Created attachment 23139
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23139
test code

compiler output:
$ g++-4.5 -std=c++0x testcase.cpp
testcase.cpp: In instantiation of 'decltype (int f(T(), "")) g(const T&) [with
T = int, decltype (f(T(), "")) = int]':
testcase.cpp:9:11:   instantiated from here
testcase.cpp:5:26: internal compiler error: in write_template_arg_literal, at
cp/mangle.c:2687
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

tested version:
4.4.4-14ubuntu5 - Crash
4.5.1 - Crash
4.5.2 - Crash
4.5.6 20110127 - Crash

[Bug c++/47488] [4.4,4.5,4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.01.27 10:56:51
            Summary|[C++0x] decltype + template |[4.4,4.5,4.6 Regression]
                   |+ string literals: ICE in   |(sizeof|decltype) +
                   |write_template_arg_literal, |template + string literals:
                   |at cp/mangle.c              |ICE in
                   |                            |write_template_arg_literal,
                   |                            |at cp/mangle.c
     Ever Confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-01-27 10:56:52 UTC ---
This c++98 variation using sizeof instead of decltype gives an ICE in the same
place:

template < typename T >
int f( const T &, const char * );

template<int> struct N { };

template < typename T >
N<sizeof( f( T(), "" ) )> g( const T &t );

void h()
{
    g( 0 );
}


This is a regression since 4.1 which doesn't ICE:

testcase.cpp: In function 'void h()':
testcase.cpp:11: sorry, unimplemented: call_expr cannot be mangled due to a
defect in the C++ ABI

[Bug c++/47488] [4.4,4.5,4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-01-27 11:09:50 UTC ---
For this variation where f<T> is not deduced, 4.4 says "sorry, unimplemented"
but doesn't ICE, 4.5 and 4.6 ICE in the same place:

template < typename T >
int f( const char * );

template<int> struct N { };

template < typename T >
N<sizeof( f<T>( "" ) )> g( const T &t );

void h()
{
    g( 0 );
}

[Bug c++/47488] [4.4,4.5,4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at redhat dot com

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> 2011-01-27 20:17:06 UTC ---
(In reply to comment #2)
> For this variation where f<T> is not deduced, 4.4 says "sorry, unimplemented"
> but doesn't ICE, 4.5 and 4.6 ICE in the same place:
> 
> template < typename T >
> int f( const char * );
> 
> template<int> struct N { };
> 
> template < typename T >
> N<sizeof( f<T>( "" ) )> g( const T &t );
> 
> void h()
> {
>     g( 0 );
> }

It is caused by revision 140120:

http://gcc.gnu.org/ml/gcc-cvs/2008-09/msg00279.html

[Bug c++/47488] [4.4,4.5,4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> 2011-01-27 20:19:23 UTC ---
(In reply to comment #1)
> This c++98 variation using sizeof instead of decltype gives an ICE in the same
> place:
> 
> template < typename T >
> int f( const T &, const char * );
> 
> template<int> struct N { };
> 
> template < typename T >
> N<sizeof( f( T(), "" ) )> g( const T &t );
> 
> void h()
> {
>     g( 0 );
> }
> 
> 

It is also caused by revision 140120:

http://gcc.gnu.org/ml/gcc-cvs/2008-09/msg00279.html

[Bug c++/47488] [4.4/4.5/4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.4.6

[Bug c++/47488] [4.4/4.5/4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug c++/47488] [4.4/4.5/4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |jason at gcc dot gnu.org
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |

[Bug c++/47488] [4.4/4.5/4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> 2011-03-08 17:06:20 UTC ---
So, the basic problem is that we still don't know how to mangle string
constants, it just changed from a sorry to an ICE.  There was a mangling
proposed on the ABI list, but while looking at it I realized that it isn't
sufficient--it produces a multiply defined symbol for

template <typename T> constexpr T f(const T* p) { return p[0]; }
template<int> struct N { };
template <typename T> void g(T, N<f((const T*)"1")>) { }
template <typename T> void g(T, N<f((const T*)"2")>) { }

int main()
{
  g('1', N<'1'>());
  g('2', N<'2'>());
}

[Bug c++/47488] sorry, unimplemented: string literal in function template signature

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-valid-code           |ABI, rejects-valid
           Priority|P2                          |P3
            Version|4.4.4                       |4.6.0
   Target Milestone|4.4.6                       |4.6.0
            Summary|[4.4/4.5/4.6 Regression]    |sorry, unimplemented:
                   |(sizeof|decltype) +         |string literal in function
                   |template + string literals: |template signature
                   |ICE in                      |
                   |write_template_arg_literal, |
                   |at cp/mangle.c              |

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> 2011-03-08 17:31:11 UTC ---
I've checked in a patch to restore the sorry, but we still need to implement a
mangling.

[Bug c++/47488] [4.4/4.5/4.6 Regression] (sizeof|decltype) + template + string literals: ICE in write_template_arg_literal, at cp/mangle.c

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> 2011-03-08 17:30:54 UTC ---
Author: jason
Date: Tue Mar  8 17:30:46 2011
New Revision: 170783

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170783
Log:
    PR c++/47488
    * mangle.c (write_template_arg_literal) [STRING_CST]: Sorry.

Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/mangle.c

[Bug c++/47488] sorry, unimplemented: string literal in function template signature

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

--- Comment #8 from Jason Merrill <jason at gcc dot gnu.org> 2011-03-08 17:39:16 UTC ---
Author: jason
Date: Tue Mar  8 17:39:10 2011
New Revision: 170785

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170785
Log:
    PR c++/47488
    * mangle.c (write_template_arg_literal) [STRING_CST]: Sorry.

Modified:
    branches/gcc-4_4-branch/gcc/cp/ChangeLog
    branches/gcc-4_4-branch/gcc/cp/mangle.c

[Bug c++/47488] sorry, unimplemented: string literal in function template signature

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

--- Comment #9 from Jason Merrill <jason at gcc dot gnu.org> 2011-03-08 17:40:33 UTC ---
Author: jason
Date: Tue Mar  8 17:40:27 2011
New Revision: 170786

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170786
Log:
    PR c++/47488
    * mangle.c (write_template_arg_literal) [STRING_CST]: Sorry.

Modified:
    branches/gcc-4_5-branch/gcc/cp/ChangeLog
    branches/gcc-4_5-branch/gcc/cp/mangle.c

[Bug c++/47488] sorry, unimplemented: string literal in function template signature

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.0                       |4.6.1

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-03-25 19:52:12 UTC ---
GCC 4.6.0 is being released, adjusting target milestone.

[Bug c++/47488] sorry, unimplemented: string literal in function template signature

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.1                       |---

[Bug c++/47488] sorry, unimplemented: string literal in function template signature

[jewillco at osl dot iu.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47488

Jeremiah Willcock <jewillco at osl dot iu.edu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jewillco at osl dot iu.edu

--- Comment #11 from Jeremiah Willcock <jewillco at osl dot iu.edu> ---
This problem still exists as of GCC 4.9.0 snapshot 20131013, with the same test
case failing.