[Bug c++/50473] New: [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[Bug c++/50473] New: [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[y121516 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

             Bug #: 50473
           Summary: [C++0x] ICE in type_has_nontrivial_copy_init, at
                    cp/tree.c:2574
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: y121516@gmail.com


ICE occured.

Codes (a.cpp):

template<unsigned N>
struct s
{};

template<class... Ts>
constexpr s<sizeof...(Ts)> f()
{
 return {};
}

template<class T>
struct test
{
 static constexpr auto&& value = f();
};

int main(){}


Compile error messages:

$ g++4.7 -std=c++0x -Wall -Wextra -pedantic a.cpp
a.cpp:14:36: internal compiler error: in type_has_nontrivial_copy_init, at
cp/tree.c:2574
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


Vesion info:

$ g++4.7 -v
Built by Equation Solution <http://www.Equation.com>.
Using built-in specs.
COLLECT_GCC=C:\cygwin\home\RiSK\misc\gcc4.7\bin\g++.exe
COLLECT_LTO_WRAPPER=c:/cygwin/home/risk/misc/gcc4.7/bin/../libexec/gcc/i686-pc-mingw32/4.7.0/lto-wrapper.exe
Target: i686-pc-mingw32
Configured with: ../gcc-4.7-20110917-mingw/configure --host=i686-pc-mingw32
--build=x86_64-unknown-linux-gnu --target
=i686-pc-mingw32
--prefix=/home/gfortran/gcc-home/binary/mingw32/native/x86_32/gcc/4.7-20110917
--with-gcc --with-gnu
-as --with-gnu-ld --with-host-libstdcxx='-lstdc++ -lsupc++ -lm'
--with-ppl=/home/gfortran/gcc-home/binary/mingw32/nat
ive/x86_32/ppl
--with-cloog=/home/gfortran/gcc-home/binary/mingw32/native/x86_32/cloog
--with-gmp=/home/gfortran/gcc-
home/binary/mingw32/native/x86_32/gmp
--with-mpfr=/home/gfortran/gcc-home/binary/mingw32/native/x86_32/mpfr --with-mp
c=/home/gfortran/gcc-home/binary/mingw32/native/x86_32/mpc
--with-sysroot=/home/gfortran/gcc-home/binary/mingw32/cros
s/x86_32/gcc/4.7-20110917 --disable-shared --disable-nls --disable-tls
--disable-win32-registry --enable-libquadmath-
support --enable-libquadmath --enable-languages=c,c++,fortran --enable-libgomp
--enable-threads=win32 --enable-lto --
enable-static --enable-shared=lto-plugin --enable-plugins --enable-ld=yes
--enable-cloog-backend=ppl
Thread model: win32
gcc version 4.7.0 20110917 (experimental) (GCC)

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-09-22
     Ever Confirmed|0                           |1

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |paolo.carlini at oracle dot
                   |                            |com

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-10-17 10:53:44 UTC ---
Jason, the call chain here is set_up_extended_ref_temp -> get_target_expr ->
get_target_expr_sfinae -> build_target_expr_with_type ->
type_has_nontrivial_copy_init, which hits gcc_assert (COMPLETE_TYPE_P (t)).

Looks like tweaking, eg, build_target_expr_with_type, to check for the
offending situation and return error_mark_node avoids the ICE, but I don't know
at the moment if something deeper is actually going on...

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-11-11 01:38:40 UTC ---
Apparently r181278 doesn't ICE anymore:

50473.C:14:36: error: taking address of temporary [-fpermissive]
50473.C:14:36: error: ‘* & s<0u>()’ is not a constant expression

but the error message seems anyway pretty obscure and actually I don't see why
the test is invalid. Jason, can you help triaging this?

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-11-11 10:13:16 UTC ---
The rvalue reference is essential. With this we still ICE:

constexpr int f() { return 1; }

template<class T>
struct test
{
  static constexpr auto&& value = f();
};

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-11 21:27:08 UTC ---
Yep, the problem seems to be that we built up trees in the template that we
don't then want to tsubst.

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

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

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

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Mon Nov 17 20:17:56 2014
New Revision: 217672

URL: https://gcc.gnu.org/viewcvs?rev=217672&root=gcc&view=rev
Log:
    PR c++/50473
    * decl.c (cp_finish_decl): Don't try to process a non-dependent
    constant initializer for a reference.
    * pt.c (value_dependent_expression_p): A reference is always
    dependent.
    * call.c (extend_ref_init_temps_1): Also clear TREE_SIDE_EFFECTS
    on any NOP_EXPRs.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/constexpr-ref5.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/call.c
    trunk/gcc/cp/decl.c
    trunk/gcc/cp/pt.c
    trunk/gcc/testsuite/g++.dg/cpp0x/constexpr-ice12.C

[Bug c++/50473] [C++0x] ICE in type_has_nontrivial_copy_init, at cp/tree.c:2574

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50473

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |5.0

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for GCC 5.