[Bug c++/50233] New: Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[Bug c++/50233] New: Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[naddiseo at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50233

             Bug #: 50233
           Summary: Internal compiler error: in build_value_init_noctor,
                    at cp/init.c:336
    Classification: Unclassified
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: naddiseo@gmail.com


Created attachment 25135
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25135
Testcase

I think shared pointers inside a union break when initialized in a constructor
list. See attached test case.

$ /usr/lib/gcc-snapshot/bin/g++ -std=c++0x  -o test.bin test.cpp
test.cpp: In constructor 'Test::Test()':
test.cpp:15:16: internal compiler error: in build_value_init_noctor, at
cp/init.c:336


$ /usr/lib/gcc-snapshot/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/usr/lib/gcc-snapshot/bin/g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc-snapshot/libexec/gcc/x86_64-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
20110308-1' --with-bugurl=file:///usr/share/doc/gcc-snapshot/README.Bugs
--enable-languages=c,ada,c++,fortran,objc,obj-c++,go
--prefix=/usr/lib/gcc-snapshot --enable-shared --enable-multiarch
--enable-linker-build-id --with-system-zlib --disable-nls --with-sysroot=/
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--enable-plugin --enable-gold --enable-ld=default --with-plugin-ld=ld.gold
--enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic
--enable-checking=yes --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.0 20110308 (experimental) [trunk revision 170786]
(Ubuntu/Linaro 20110308-1)

[Bug c++/50233] Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50233

Daniel Krügler <daniel.kruegler at googlemail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |daniel.kruegler at
                   |                            |googlemail dot com

--- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-08-30 06:33:44 UTC ---
Seems to be fixed in 4.7.0 (Tested with 4.7.0 20110820 (experimental))

[Bug c++/50233] Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50233

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-08-30 09:14:25 UTC ---
Good. 4_6-branch behaves the same. Do we agree that GCC is correct in rejecting
this (without ICE-ing of course)?

[Bug c++/50233] Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50233

--- Comment #3 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-08-30 09:30:48 UTC ---
(In reply to comment #2)
> Good. 4_6-branch behaves the same. Do we agree that GCC is correct in rejecting
> this (without ICE-ing of course)?

I think that gcc is right rejecting it. The case is similar to the following
one:

int main()
{
  constexpr int i{};
  constexpr const int* p = &i;
}

This program is ill-formed, because i is a variable without static storage
duration, and thus does not allow for forming an address-constant expression.

[Bug c++/50233] Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50233

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
      Known to work|                            |4.6.2
         Resolution|                            |FIXED

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-08-30 09:37:29 UTC ---
Excellent.

[Bug c++/50233] Internal compiler error: in build_value_init_noctor, at cp/init.c:336

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50233

--- Comment #5 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-08-30 09:52:19 UTC ---
I just notice that the current exclusion of reinterpret_cast in constant
expressions would make it impossible to define addressof as a constexpr
function. C++11 currently invalidates the special portable language rule of
reinterpret_cast, addressof is based on, see also the recent example given in
bug 49171, comment 2.