[CMake] Fwd: how do I test if a library target is static or shared?

[Aleksander Demko]

I guess I'm looking for a way to automatically "relay" information
between the main project B and one or more library projects A, etc. My
projects tend to involve lots of sub libraries, so I need a way for
this to work in a scalable manner.

If I try to simply INCLUDE A in B, then all the relative source paths
in the add_library call do not work. Is there a nice work around for
this?

My current solution involves that I, in executable B, do an
ADD_SUBDIRECTORY on A. I then have a few (gross) macros that help me
propagate the include dirs and defines in A up to B. The macros
inspect and manipulate the COMPILE_FLAGS properties of the targets.
Here is a short example (my macros are named I_*):

...
ADD_SUBDIRECTORY(${DBA_SRC_PATH} dba)
...
ADD_LIBRARY(wxdba wxdba/colour_fi...
I_ADD_RELATIVE_INCLUDE(wxdba .)
I_TARGET_LINK_LIBRARY(wxdba dba)
I_ADD_COMPILE_FLAGS(wxdba /DwxUSE_UNICODE)

Then sub executables can use wxdba and include all the cflags, include
directories needed for both wxdba and its dependent project dba. The
wxdba project also inherited any cflags/include directories that dba
had via the I_TARGET... call.

I was hoping for a more mainstream approach that requires less
specialized macros.

On Mon, Sep 22, 2008 at 7:41 PM, Mike Jackson
<mike.jackson at bluequartz.net> wrote:
> Not totally sure what you are after BUT one possible implementation is
> something like the following.
>
> If you have a Library A that you want to include in Executable B and Both
> are there own projects based on CMake then there is "some" integration that
> can happen.
>
> So for library A you have a normal CMakeLists.txt file for that project.
> Then for the executable project you simply "include" the CMakeLists.txt file
> from library A.
>
> If the "Library A" project you have:
> add_library (A SHARED ${sources})
>
> Then in the executable project you have something like:
>
> add_executable (myexec ${sources} )
> target_link_libraries(myexec A)
>
> When you build the executable project CMake will automatically build the "A"
> library first. This is one way to achieve this. ( I do this in a few of my
> projects ).
>
>
>
> Some helper code that might be handy:
> # This code goes in the Executable projects CMakeLists.txt file
> # --- Get the LibA Project by looking for a folder called "src" in the
> LibraryA folder
> GET_FILENAME_COMPONENT(CURRENT_SOURCE_PARENT ${CMAKE_CURRENT_SOURCE_DIR}
> PATH)
> FIND_PATH(A_SOURCE_DIR src
>  "${CURRENT_SOURCE_PARENT}/LibraryA"
> )
> IF (NOT A_SOURCE_DIR)
>    MESSAGE(FATAL_ERROR "Could not find LibraryA Directory. Please set the
> directory")
> ENDIF(NOT MXA_SOURCE_DIR)
>
> Now. if you can not do something like the above or you don't want to tie the
> projects together like that then you can "configure" a header file from
> LibraryA that can be used in the executable project to "relay" information
> about the library, like if it was built as a shared or static library.
> Again, this is also done in lots of projects.
>
> The last way to "relay" information would be to have CMake write the
> information into a simple text file that the executable project can then
> parse.
>
> Keep asking.. we'll help as much as we can.
> ---
> Mike Jackson - Principal Software Engineer
> www.bluequartz.net
>
>
>
>
> On Sep 22, 2008, at 5:46 PM, Aleksander Demko wrote:
>
>> Dang, that won't work for me. I'm in effect trying to make my own
>> EXPORT like command (export doesn't maintain C flags or other stuff I
>> need) so I need to be able to gleam a bunch of info from the library
>> targets dynamically.
>>
>> Basically I want to quickly build one library in one cmake session,
>> than import it in another (without have to write custom Find-.cmake
>> files etc). Maybe this exists already in cmake, but I can't seem to
>> find it.
>>
>>
>> On Mon, Sep 22, 2008 at 4:32 PM, Mike Jackson
>> <mike.jackson at bluequartz.net> wrote:
>>>
>>> You will probably have to set your own variable into the cache and then
>>> check that variable later on in your scripts
>>>
>>>
>>>
>>> On Sep 22, 2008, at 5:23 PM, Aleksander Demko wrote:
>>>
>>>> On Mon, Sep 22, 2008 at 4:15 PM, Mike Jackson
>>>> <mike.jackson at bluequartz.net> wrote:
>>>>>
>>>>> Assuming you mean a library that you are creating the default is
>>>>> static.
>>>>> If
>>>>> you want a dynamic library then use the "SHARED" keyword:
>>>>>
>>>>> add_library (mylib SHARED libsource.cpp)
>>>>>
>>>>
>>>> I understand that. But later in my script I want to check if mylib is
>>>> shared or static with an IF command. I want the command to know if the
>>>> add_library was the default static, shared or shared because
>>>> BUILD_SHARE_LIBS is true.
>>
>> _______________________________________________
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>
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