[Bug c++/50800] New: Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[Bug c++/50800] New: Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[mathias at gaunard dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

             Bug #: 50800
           Summary: Internal compiler error in finish_member_declarations,
                    possibly related to may_alias attribute
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mathias@gaunard.com


The attached preprocessed testcase results in an internal compiler error:

/home/gaunard/dev/boost/trunk/boost/type_traits/detail/cv_traits_impl.hpp:36:1:
internal compiler error: in finish_member_declaration, at cp/semantics.c:2559

This seems to be tied to the use of the may_alias attribute.

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[mathias at gaunard dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #1 from Mathias Gaunard <mathias at gaunard dot com> 2011-10-19 18:20:06 UTC ---
Testcase is here (couldn't attach it due to bugzilla size restrictions):
http://mathias.gaunard.com/data/ice_finish_member_declaration.cpp

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2011-10-19
     Ever Confirmed|0                           |1

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-10-19 23:56:54 UTC ---
That you couldn't attach it should tell you something... Please do your best to
reduce its size: http://gcc.gnu.org/wiki/A_guide_to_testcase_reduction

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[mathias at gaunard dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #3 from Mathias Gaunard <mathias at gaunard dot com> 2011-10-20 20:07:24 UTC ---
Created attachment 25562
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25562
Reduced testcase

Original testcase reduced using automated delta tools

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[regehr at cs dot utah.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #4 from John Regehr <regehr at cs dot utah.edu> 2011-12-03 07:01:50 UTC ---
Created attachment 25977
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25977
smaller test case

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[regehr at cs dot utah.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #5 from John Regehr <regehr at cs dot utah.edu> 2011-12-05 22:07:16 UTC ---
Created attachment 25997
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25997
smaller again

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[mathias at gaunard dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #6 from Mathias Gaunard <mathias at gaunard dot com> 2012-08-14 10:53:07 UTC ---
I've had this happen with 4.7.1 without any may_alias involved.

Why is this bug still marked 'waiting'? Are more testcases necessary?

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

--- Comment #7 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-08-14 10:58:40 UTC ---
Became "Waiting" with Comment #2 and then nobody updated the status, it's as
simple as that.

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[glisse at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #8 from Marc Glisse <glisse at gcc dot gnu.org> 2012-08-14 11:03:31 UTC ---
Although if you have a testcase without may_alias, you should attach it.

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[kretz at kde dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

Matthias Kretz <kretz at kde dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kretz at kde dot org

--- Comment #9 from Matthias Kretz <kretz at kde dot org> ---
I assume I hit the same issue. I got the testcase down to a few lines:

#include <type_traits>
template <typename L> typename std::remove_reference<L>::type foo(L &&lhs, int
rhs);
template <typename T> T d(T i)
{
  enum { Size = sizeof(int) };
  return foo(i, Size);
}
template <typename T> struct A {
  typedef int TA __attribute__((__may_alias__));
};
int main()
{
  typedef A<int> V;
  typedef typename std::remove_reference<typename V::TA &>::type T;
  return d(1);
}

It only needs the -std=c++11 flag. Tested to fail: 4.8.0/1/2/3 and 4.9.0/1/2
(4.9.2 is 20140924).

Backtrace from 4.9.2 snapshot:
/opt/gcc-4.9-snapshot/include/c++/4.9.2/type_traits:1488:5: internal compiler
error: in finish_member_declaration, at cp/semantics.c:2827
     { typedef _Tp   type; };
     ^
0x6395c0 finish_member_declaration(tree_node*)
        ../.././gcc/cp/semantics.c:2827
0x5b975d instantiate_class_template_1
        ../.././gcc/cp/pt.c:9244
0x5b975d instantiate_class_template(tree_node*)
        ../.././gcc/cp/pt.c:9445
0x61039d complete_type(tree_node*)
        ../.././gcc/cp/typeck.c:134
0x5a8531 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../.././gcc/cp/pt.c:12163
0x5acac7 tsubst_function_type
        ../.././gcc/cp/pt.c:11344
0x5a7e7f tsubst(tree_node*, tree_node*, int, tree_node*)
        ../.././gcc/cp/pt.c:12081
0x5ae8fe tsubst_decl
        ../.././gcc/cp/pt.c:10596
0x5a822f tsubst(tree_node*, tree_node*, int, tree_node*)
        ../.././gcc/cp/pt.c:11543
0x5b09fb instantiate_template_1
        ../.././gcc/cp/pt.c:15580
0x5b09fb instantiate_template(tree_node*, tree_node*, int)
        ../.././gcc/cp/pt.c:15630
0x5b6c2e fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node*
const*, unsigned int, tree_node*, unification_kind_t, int, bool, bool)
        ../.././gcc/cp/pt.c:15979
0x574031 add_template_candidate_real
        ../.././gcc/cp/call.c:2998
0x571984 add_template_candidate
        ../.././gcc/cp/call.c:3095
0x571984 add_candidates
        ../.././gcc/cp/call.c:5169
0x5755d9 perform_overload_resolution
        ../.././gcc/cp/call.c:3904
0x5770ea build_new_function_call(tree_node*, vec<tree_node*, va_gc,
vl_embed>**, bool, int)
        ../.././gcc/cp/call.c:3981
0x639891 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
        ../.././gcc/cp/semantics.c:2358
0x5a1b34 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../.././gcc/cp/pt.c:14861
0x5a519c tsubst_expr
        ../.././gcc/cp/pt.c:14048

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |trippels at gcc dot gnu.org

--- Comment #10 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
markus@x4 tmp % cat finish.ii
template <typename>
struct B;
template <typename _Tp>
struct B<_Tp &> {
  typedef _Tp type;
};
template <typename L>
typename B<L>::type foo(L &&);
int a;
struct A {
  typedef int TA __attribute__((__may_alias__));
};
void d() { foo(a); }
int main() { B<A::TA &> b; }

markus@x4 tmp % g++ -std=c++11 finish.ii
finish.ii: In instantiation of ‘struct B<int&>’:
finish.ii:15:25:   required from here
finish.ii:4:17: internal compiler error: in finish_member_declaration, at
cp/semantics.c:2844
>From gcc-bugs-return-462638-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Fri Sep 26 13:06:43 2014
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Subject: [Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idP800

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.4
      Known to fail|                            |4.8.3, 4.9.1, 5.0

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         Depends on|                            |18174
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org

--- Comment #12 from Jason Merrill <jason at gcc dot gnu.org> ---
This is related to the fix for bug 18174, which made int& a different type from
A::TA&.  But this difference is not reflected in the mangling, so B<int&> and
B<A::TA&> have the same mangling, which we can't allow.

The compiler tries to handle this by stripping attributes from template
arguments, so that B<A::TA&> is treated as B<int&>.  This was failing in this
case because the middle end was giving the two types different TYPE_CANONICAL. 
I guess we need to work harder at stripping the attributes.

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #13 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Thu Apr 23 15:55:21 2015
New Revision: 222377

URL: https://gcc.gnu.org/viewcvs?rev=222377&root=gcc&view=rev
Log:
    PR c++/50800
    * tree.c (strip_typedefs): Add remove_attributes parm.
    (strip_typedefs_expr): Likewise.
    (apply_identity_attributes): New subroutine of strip_typedefs.
    * pt.c (canonicalize_type_argument): Let strip_typedefs handle attrs.
    (convert_nontype_argument, unify): Likewise.
    * cp-tree.h: Adjust.

Added:
    trunk/gcc/testsuite/g++.dg/ext/attrib50.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/pt.c
    trunk/gcc/cp/tree.c
    trunk/gcc/testsuite/g++.dg/abi/mangle40.C
    trunk/gcc/testsuite/g++.dg/ext/alias-canon2.C
    trunk/gcc/testsuite/g++.dg/ext/alias-mangle.C

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #15 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Fri Apr 24 20:53:28 2015
New Revision: 222426

URL: https://gcc.gnu.org/viewcvs?rev=222426&root=gcc&view=rev
Log:
    PR c++/50800
    * g++.dg/ext/alias-canon2.C: Remove clashing fn definitions.

Modified:
    trunk/gcc/testsuite/g++.dg/ext/alias-canon2.C

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #16 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Tue Apr 28 14:43:54 2015
New Revision: 222530

URL: https://gcc.gnu.org/viewcvs?rev=222530&root=gcc&view=rev
Log:
        PR c++/50800
        * tree.c (strip_typedefs): Add remove_attributes parm.
        (strip_typedefs_expr): Likewise.
        (apply_identity_attributes): New subroutine of strip_typedefs.
        * pt.c (canonicalize_type_argument): Let strip_typedefs handle attrs.
        (convert_nontype_argument, unify): Likewise.
        * cp-tree.h: Adjust.

Added:
    trunk/gcc/testsuite/g++.dg/ext/attrib50.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/pt.c
    trunk/gcc/cp/tree.c
    trunk/gcc/testsuite/g++.dg/abi/mangle40.C
    trunk/gcc/testsuite/g++.dg/ext/alias-mangle.C

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

--- Comment #17 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Apr 29 20:51:05 2015
New Revision: 222591

URL: https://gcc.gnu.org/viewcvs?rev=222591&root=gcc&view=rev
Log:
        PR c++/50800
        * tree.c (apply_identity_attributes): Fix handling of classes.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/alignas3.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/tree.c

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tim at klingt dot org

--- Comment #18 from Paolo Carlini <paolo.carlini at oracle dot com> ---
*** Bug 57472 has been marked as a duplicate of this bug. ***

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.5                       |---

[Bug c++/50800] Internal compiler error in finish_member_declarations, possibly related to may_alias attribute

[edanor1 at wp dot pl]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50800

edanor1 at wp dot pl <edanor1 at wp dot pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |edanor1 at wp dot pl

--- Comment #19 from edanor1 at wp dot pl <edanor1 at wp dot pl> ---
Hi everyone,

I just got a similar output on GCC 5.1.0. I think it might be related, however
this appears to be for different syntax.

Flags are: "-mavx -std=c++11 -Wfatal-errors -O0"

Please let me know if you still need a test case.

.../BOOST/boost_1_57_0/boost/type_traits/remove_reference.hpp:42:1: note: in
expansion of macro ‘BOOST_TT_AUX_TYPE_TRAIT_PARTIAL_SPEC1_1’
 BOOST_TT_AUX_TYPE_TRAIT_PARTIAL_SPEC1_1(typename T,remove_reference,T&,T)
 ^
0x6ef1fc finish_member_declaration(tree_node*)
        ../../gcc/cp/semantics.c:2872
0x66af2d instantiate_class_template_1
        ../../gcc/cp/pt.c:9487
0x66af2d instantiate_class_template(tree_node*)
        ../../gcc/cp/pt.c:9688
0x6c5bed complete_type(tree_node*)
        ../../gcc/cp/typeck.c:146
0x653e5f tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:12441
0x65e759 tsubst_template_args
        ../../gcc/cp/pt.c:10257
0x65ec84 tsubst_aggr_type
        ../../gcc/cp/pt.c:10454
0x653891 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:11909
0x66b909 instantiate_class_template_1
        ../../gcc/cp/pt.c:9275
0x66b909 instantiate_class_template(tree_node*)
        ../../gcc/cp/pt.c:9688
0x6c5bed complete_type(tree_node*)
        ../../gcc/cp/typeck.c:146
0x653e5f tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:12441
0x6519e1 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/cp/pt.c:14654
0x6514e5 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/cp/pt.c:15066
0x653320 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:12530
0x660c02 tsubst_decl
        ../../gcc/cp/pt.c:11339
0x653c54 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc/cp/pt.c:11830
0x66aed2 instantiate_class_template_1
        ../../gcc/cp/pt.c:9424
0x66aed2 instantiate_class_template(tree_node*)
        ../../gcc/cp/pt.c:9688
0x6c5bed complete_type(tree_node*)
        ../../gcc/cp/typeck.c:146
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idf771

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Oops sorry, I mean:

   if (!m_input.getline(buf, sizeof(buf)))
     return false;

The version comparing to 0 only works in C++03 (or non-conforming versions of
libstdc++ pre-gcc-5) because testing a stream's state is done via implicit
conversion to void*.

In C++11 it is done via explicit conversion to bool, which is triggered by an
explicit cast to bool, or a use in a conditional statement, or by negating it
with !