[CMake] Proper way to export a library

[Matthew Woehlke]

On 2013-11-02 13:38, Cyrille Faucheux wrote:
> [...] from what I understood from Matthew first answer ("implicit compile
> flags [...] for imported tagets"), I was under the impression that I could
> get MYPROJECT_STATIC automatically defined when linking another program
> against a static version of my library (through its imported target).

Yes and no. *You* have to set the flag as part of your library's 
interface compile definitions. But once you do that, cmake should export 
that, and anyone linking to your library (via imported target) should 
automatically pick up the flag.

> I've looked the documentation of target_compile_definitions, but it seems
> to be about compiling the library, not linking against its imported target.
> Am I right?

No; at least not entirely in the case of 't_c_d({PUBLIC|INTERFACE})'. A 
PUBLIC definition is used both to compile your library and by anyone 
linking to it. An INTERFACE definition is used *only* by other targets 
linking to it.

See also the INTERFACE_COMPILE_DEFINITIONS property and note in the 
t_c_d documentation how t_c_d affects that property.

-- 
Matthew