http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55670
Bug #: 55670
Summary: This isn't a pure virtual method.
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: qufa...@gmail.com
Target: x86_64-linux-gnu
Build: gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-11precise2)
Created attachment 28944
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28944
Preprocessed contents of fptest2.cpp
I've been enjoying the new C++11 features in 4.7. But the combination of
template aliases and non-static data member initialization seems to have caught
a corner-case of pure virtual method parsing.
==== CONTENTS OF fptest.cpp ====
template <class T> using F = T;
struct X {
F<void ()>* fp = nullptr;
};
int main () { return 0; }
================================
I expected this to compile without error, but instead I got:
==== OUTPUT OF g++-4.7 -std=c++11 fptest.cpp ====
fptest.cpp:3:29: error: invalid pure specifier (only ‘= 0’ is allowed) before
‘;’ token
=================================================
It compiles if I set fp to nullptr in a constructor, and it compiles if I
declare fp with traditional function pointer syntax, " void (* fp ) ()". It
gives the same error if I initialize fp to the address of a function instead of
nullptr.
Just for kicks, I decided to see what would happen if I tried to initialize fp
to 0.
==== OUTPUT OF g++-4.7 -std=c++11 fptest2.cpp ====
fptest2.cpp:4:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccjdsX7p.out file, please attach this to
your bugreport.
==================================================
Oh. Well then.
==== OUTPUT OF g++-4.7 -v ====
Using built-in specs.
COLLECT_GCC=g++-4.7
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.2-11precise2' --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 --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-11precise2)
==============================
