[CMake] Toggling a Preprocessor macro for targets within a single project

[Michael Jackson]

On Feb 20, 2009, at 8:51 AM, Christian Ehrlicher wrote:

> Michael Jackson schrieb:
>>
>> On Feb 20, 2009, at 4:59 AM, Eric Noulard wrote:
>>
>>> 2009/2/20 Christian Ehrlicher <Ch.Ehrlicher at gmx.de>:
>>>>> Von: Andreas Pokorny
>>>>> Hello,
>>>>> Wow that was fast. Thanks a lot.
>>>
>>> Obviously I was too fast reading the doc :-)
>>>
>>>>>> [...]
>>>>>>
>>>>>> SET_TARGET_PROPERTIES(PlatformLib PROPERTIES
>>>>>>                                           DEFINE_SYMBOL  
>>>>>> USE_TRACER)
>>>>>>
>>>>>> Then you shouldn't have to ADD_DEFINITIONS and  
>>>>>> REMOVE_DEFINITIONS?
>>>>>
>>>>>
>>>>> I do not understand why.. but DEFINE_SYMBOL did not work, but
>>>>> COMPILE_FLAGS -DUSE_TRACER
>>>>> did. So SET_TARGET_PROPERTIES is the sledgehammer for getting it
>>>>> done :)
>>>>>
>>>> DEFINE_SYMBOL only works for shared libraries. see cmake
>>>> documentation: "DEFINE_SYMBOL sets the name of the preprocessor
>>>> symbol defined when compiling sources in a shared library."
>>>
>>> Thank you  Christian
>>> ...for reading the doc more carefully  than I do :-)
>>>
>>>
>>> -- 
>>> Erk
>>>
>>
>> and I _think_ that DEFINE_SYMBOL only will work on windows as it is
>> there to facilitate the dllImport/dllexport functionality used by
>> windows for exporting/importing symbols from shared libraries.
>>
>> I may be wrong on that as I am going on memory at this point.
>>
> This is wrong - you've a similar option with gcc - the visibility  
> attribute.
>
>
> Christian

Yep. you are correct. I was away from my machine and so was obviously  
remembering things in-correctly.

Mike