[cairo] _cairo_win32_tmpfile()

[Augusto Radtke]

> That's indeed very untested.  You mean, if CAIRO_WIN32_STATIC_BUILD is defined
> we should define cairo_public to nothing?  That makes sense, does this work
> better:
>
> #ifndef cairo_public
> # if _MSC_VER && ! CAIRO_WIN32_STATIC_BUILD
> #  define cairo_public __declspec(dllimport)
> # else
> #  define cairo_public
> # endif
> #endif

It's getting better, but there is another issue, we should use
__declspec(dllexport) when building a DLL. I can't found yet a way to
make that work without some define at some point of the process, like
CAIRO_WIN32_STATIC_BUILD, this is how I solved the problem internally
on my software:

#if defined(_WIN32)
	#if defined(SCULLY_API_EXPORT)
			#define SCULLY_API __declspec(dllexport)
	#elif defined(SCULLY_API_IMPORT)
			#define SCULLY_API __declspec(dllimport)
	#else
			#define SCULLY_API
	#endif
#else
	#if defined(SCULLY_API_IMPORT)
		#define SCULLY_API extern
	#else
		#define SCULLY_API
	#endif
#endif

The default here it's to build statically, so if I'm building
statically I don't have to define nothing on either points (library
compilation and library usage by third party). If I'm not compiling
statically I define SCULLY_API_EXPORT when compiling the library and
SCULLY_API_IMPORT on using the library headers. I believe cairo as
open-source it's mostly used as an external library instead of being
building statically, so it should stand for a different default:

#ifndef cairo_public
    #if _MSC_VER && CAIRO_WIN32_BUILD_DLL
        #define cairo_public __declspec(dllexport)
    #elif _MSC_VER && !CAIRO_WIN32_BUILD_DLL
        #define cairo_public __declspec(dllimport)
    #elif CAIRO_WIN32_BUILD_DLL
        #define cairo_public extern
    #else
        #define cairo_public
    #endif
#endif

That means that we should always build cairo with
CAIRO_WIN32_BUILD_DLL set if we are building a DLL, but the person
using that DLL can go direct to #include <cairo.h> without caring
about any magic define. Also if the person want a static build of
cairo it can build directly and use directly without magic define. The
responsibility of setting correct defines goes to the DLL builder. The
extern defined on the second #elif is to people building a DLL on GCC,
does it use extern as somekind of __declspec(dllexport)? This is
something I need some light from someone else.

Augusto