Re: [Tinycc-devel] Crosscompiling

[Michael Matz]

On Fri, 27 Jun 2014, Markus Bergholz wrote:

>       Make it clear where “mexPrintf” is defined and why it is not
>       effective.
>
>
> "mexPrintf" is defined in /usr/include/octave-3.8.1/octave/mexproto.h afaiu.

That's a declaration, not a definition.  The definition comes from some 
Octave internal library.  On linux you can build shared libraries that 
contain references to undefined symbols (like 'mexPrintf') that will then 
be resolved when loading the library (Octave itself or some library it 
depends on will define that symbol).  That's what happens for your working 
example (your helloworld.mex will actually be an ELF shared library 
containing unresolved references to mexPrintf).

When you try the same for Windows you'll actually build a DLL.  When it's 
supposed to contain references to external symbols then you at least need 
a .def file that describes which library will provide that symbol later. 
You'll also need to generate a .lib file describing the symbols exported 
by your helloworld.mex (so that octave can load it).

Generally for Octave the right way to create .mex files seems to be to use 
the helper program/script mkoctfile (with --mex), which presumably 
contains all the right libraries and other link parameters for each 
platform.  If Octave supports external commands on Windows at all.

This all is not TCC specific, it's a problem in how you use Octaves system 
for C bindings.  You'll probably get better answers asking their 
developers.


Ciao,
Michael.