Re: [Openexr-devel] "Half" support in C?

[Bob Friesenhahn]

On Wed, 2 Mar 2005, Drew Hess wrote:

> Bob Friesenhahn <address@hidden> writes:
>
> > The typical situation is that it is easy for GCC code to link with
> > OS/vendor libraries (the normal case).  It is problematic for vendor
> > compilers to link with libraries build with GCC (even C libraries)
> > because code built with GCC expects certain support functions
> > (e.g. _eprintf) to exist.  Adding libgcc to the mix may cause other
> > problems (e.g. duplicate symbols).
>
> "May," or "has" ?  I find it hard to believe that in practice you'd
> encounter code and/or a vendor compiler that has symbol conflicts with
> libgcc, given how popular that compiler is.

Has.  The libgcc library provides support for important things like 
static initialization and low-level error reporting which are needed 
when GCC is used to do the linking.  The vendor compiler has its own 
way of doing things.

> What I'm proposing is not that you link a C++ library into your C
> code, but that you wrap the C++ library (libHalf, in this case) with a
> C library, and then link that C library into your application.  If the
> C++ library is statically linked into the C wrapper, I don't think
> you'd need a C++-aware linker.

Due to static initialization (including C++ exception related 
handling) it is risky to not use a C++-aware linker.  If there were 
any statically allocated C++ objects there may also be problems.

Bob
======================================
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/