[LLVMdev] converting C++ to C question

[Luke Dalessandro]

Michael Reichenbach wrote:
> Please bare with me. :) Just to ensure I got nothing wrong.
> 
> I can write in C++ + use C++ std lib + use other C++ libs and see if it
> compiles with a C++ compiler.
> 
> After it's working I use llvm to do some magic and I get C code that I
> can compile with a standard C compiler on any platform? That's what I
> planed to do.

It's not the compiler that's causing the problem. All of the C++-isms 
are getting converted into C, which you can then compile with a C 
compiler. This includes things like new/delete, operator overloading, etc.

The problem is that you are using code found in the standard C++ library 
which the linker can't find at link time. When you use the g++ driver to 
do linking, it knows about the standard library and "does the right 
thing" during linking. If you use the system linker you need to tell it 
where to find the standard C++ library. You do this in LLVM by passing 
-lstdc++ to llvm-ld during linking.

So the answer to your question is "yes" you can generate C code that 
will compile on any platform, but in order to link it correctly you need 
to link in the C++ library on that platform.

Hope this helps.

Luke

> 
> Regards,
> -mr
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