[cfe-dev] Typeid and forward declaration - Clarification needed

[Karen Shaeffer]

On Wed, Oct 30, 2013 at 11:51:13PM +0000, Karen Shaeffer wrote:
> On Wed, Oct 30, 2013 at 10:24:50PM +0000, Karen Shaeffer wrote:
> > On Tue, Oct 29, 2013 at 10:00:41PM +0000, Karen Shaeffer wrote:
> > > > 
> > > > The wording was added by DR206 in response to the ambiguity in the original
> > > > (C++98) spec. Since this was a DR, it retroactively applies to C++98 too,
> > > > so this code has (in some sense) always been ill-formed, with no diagnostic
> > > > required:
> > > > 
> > > > http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#206
> > > > 
> > > > I'm not sure what you're talking about when you mention ambiguity.
> > > 
> > > Hi Richard,
> > > I simply meant the standard is clear and concise as you point out. And this
> > > issue has nothing to do with the discretion of the implementation. It is an
> > > ill-formed program. Thank you very much for clarifying the details. Very helpful.
> > > 
> > 
> > I work with Ubuntu 13.10 these days and am quite pleased to learn clang-3.3 is supported
> > by Ubuntu Saucy universe repositories.
> > 
> > root at ip-212-12-37-96:/etc/apt# dpkg --get-selections | grep llvm
> > libllvm3.3:amd64				install
> > llvm-3.3					install
> > llvm-3.3-dev					install
> > llvm-3.3-doc					install
> > llvm-3.3-runtime				install
> > root at ip-212-12-37-96:/etc/apt# dpkg --get-selections | grep clang
> > clang-3.3					install
> > libclang-common-3.3-dev				install
> > libclang1-3.3					install
> > 
> > My understanding is clang-3.3 provides full support for c++11 standard. That is one of my
> > requirements. Next step is to do comparison testing on performance of compiled binaries.
> > That is a critically important metric I am looking at.
> 
> $ ldd /usr/bin/clang
> 	linux-vdso.so.1 =>  (0x00007fffc99fe000)
> 	libLLVM-3.3.so.1 => /usr/lib/x86_64-linux-gnu/libLLVM-3.3.so.1 (0x00007f41cfe0d000)
> 	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f41cfbf0000)
> 	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f41cf8eb000)
> 	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f41cf6d5000)
> 	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f41cf30d000)
> 	libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f41cf104000)
> 	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f41cef00000)
> 	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f41cebfc000)
> 	/lib64/ld-linux-x86-64.so.2 (0x00007f41d148b000)
> 
> I guess you need to roll your own to use libc++. Even so, it is a great jumping off point
> to have all this available on Ubuntu Saucy without needing to be a pioneer. Maybe I'll use
> this compiler to start a bootstrap of the 3.4 release in January.

This tool chain doesn't actually work out of the box on Ubuntu. I see clang needs
binutils-gold. I am OK with that. But after looking into it, I apparently need to break
my default GNU tool chain to use it. I am not willing to do that.

enjoy,
Karen