[Bug c++/55879] New: [C++11][constexpr] nested constexpr Initialisation raises internal compiler error

[npl at chello dot at]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55879



             Bug #: 55879

           Summary: [C++11][constexpr] nested constexpr Initialisation

                    raises internal compiler error

    Classification: Unclassified

           Product: gcc

           Version: 4.7.2

            Status: UNCONFIRMED

          Severity: critical

          Priority: P3

         Component: c++

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: n...@chello.at





Created attachment 29084

  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29084

code to raise the error



Compiling the added code results in an internal compiler error, I tested this

with GCC 4.6.3 and 4.7.2, both fail at different lines though. Some notes:

for 4.7.2:

*) I tested using a defaulted copy-constructor, this fixes the issue

*) removing the constexpr fixes the issue

for 4.6.3:

*) I havent tested the provided code itself (have no access to 4.6.3 right

now), I used slightly bigger version of the code. Im hopefull it still causes

trouble.

*) the important part is to use an external variable but have an additional

entry in the array with an constant



I dint provide a preprocessed source because I hope this is a sufficiently

small piece to reproduce the error easily. Since this seems a rather fragile

issue right now I guess it would be a good idea to create some bigger tests and

check other gcc versions aswell - thats the reason I have code to break both

versions in one file instead of simplifying it further.



---------------Command used (4.7.2/4.6.3 respectively):

g++ -std=c++11 nestedconstexpr.cpp

g++ -std=c++09 nestedconstexpr.cpp

---------------Compiler version:

Using built-in specs.

COLLECT_GCC=g++

COLLECT_LTO_WRAPPER=/usr/lib/gcc/i486-linux-gnu/4.7/lto-wrapper

Target: i486-linux-gnu

Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.2-4'

--with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs

--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr

--program-suffix=-4.7 --enable-shared --enable-linker-build-id

--with-system-zlib --libexecdir=/usr/lib --without-included-gettext

--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7

--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu

--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object

--enable-plugin --enable-objc-gc --enable-targets=all --with-arch-32=i586

--with-tune=generic --enable-checking=release --build=i486-linux-gnu

--host=i486-linux-gnu --target=i486-linux-gnu

Thread model: posix

gcc version 4.7.2 (Debian 4.7.2-4)