[CMake] Function for visibility definitions

[Hilton Medeiros]

Wow, now you got me.
That is why I love discussions.
Thanks for your insight, now I (my hard-as-rock head) can understand
why this is not feasible.

As a side note I think this should be in a list, maybe in the wiki, to
advise others no to do this. A list of 'do not even think about this'.

I'm sorry for the incovenient.

Kind regards,
Hilton

On Thu, 11 Feb 2010 02:26:27 -0500
Mike Jackson <mike.jackson at bluequartz.net> wrote:

> And what happens when a project wants to use my library? That
> project must now use Cmake and your macro. What if a project
> downstream can not use Cmake to define those macros? What then?
> 
> Mike Jackson
> 
> On Feb 11, 2010, at 2:04, Hilton Medeiros
> <medeiros.hilton at gmail.com> wrote:
> 
> > Hello Christian,
> >
> > thanks for the interest, let me explain:
> >
> > ## In your CMake file you could to do this:
> > ...
> > include (VisibilityDefinitions)
> > add_visibility_definitions(PREFIX PROJECT)
> > ...
> > ##
> >
> > // In your project source, this:
> > ...
> > class PROJECT_EXPORTS ExampleClass {...};
> > ...
> > //
> >
> > It is really simple, the function will just add these
> > definitions, through CMake of course, in compile time like this:
> >
> > g++ -DPROJECT_EXPORTS=__attribute__((visibility("default")))
> >    -DPROJECT_PRIVATE=__attribute__((visibility("hidden")))
> >    src/ExampleClass.cpp
> >
> > But of course you won't see anything like this while compiling
> > because CMake shows only:
> > "Building CXX object CMakeFiles/example.dir/src/ExampleClass.cpp.o"
> >
> > Also, by the signature of the function you could custom these
> > definitions just like you want them, like this:
> >
> > add_visibility_definitions(PREFIX _MyLib
> >                           EXPORT_SUFFIX Export
> >                           PRIVATE_SUFFIX Private)
> >
> > And in your source code:
> >
> > class _MyLibExports ExampleClass {...};
> > class _MyLibPrivate ExampleClass {...};
> >
> > Kind regards,
> > Hilton
> >
> > On Thu, 11 Feb 2010 07:41:32 +0100
> > Christian Ehrlicher <Ch.Ehrlicher at gmx.de> wrote:
> >> Hilton Medeiros schrieb:
> >>> Thanks for pointing that mistake, I fixed it.
> >>>
> >>> About g++: g++ is gcc with -lstdc++
> >>>
> >>> What is wrong with a simple CMake file?
> >>> I know what is good about it, if CMake had it built in
> >>> neither me nor any CMake user would need to write neither a simple
> >>> header file nor a simple CMake file.
> >>>
> >> I don't see how this should work without a header file. How should
> >> i use those defines in my source at all?
> >> The better have a simple header-file...
> >>
> >>
> >> Christian
> >>
> >
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