[CMake] build directories, subdirs and lib dependencies

[Nick Arini]

Brad,

thanks for this.
I have done what you suggested and it actually makes the whole project 
folder much neater.

Cheers,

Nick

Brad King wrote:

> Nick Arini wrote:
>
>> I have a source directory structure with a root directory containing 
>> a top level CMakeLists.txt file and some code to build a front end 
>> executable. I also have a couple of sub directories which contain 
>> libraries which are required to link to the executable in the top 
>> level directory for the program to function correctly. I would like 
>> to step into each of these subdirs in turn (the libraries themselves 
>> have interdependencies) and build each library then build the front 
>> end executable and link the libraries.
>>
>> In my top level CMakeLists.txt file I first step into the subdirs for 
>> each library in turn:
>
> [snip]
>
>> How do I get CMake to build the libraries first then link to the 
>> executable (in actual fact if you ignor the error and build anyway it 
>> does the right thing!)?
>
>
> The make system generated by CMake does a pre-order traversal, so 
> directories can depend on their parents and earlier siblings, but not 
> on their children.  This was chosen so that test executables could be 
> in subdirectories below the libraries they test.  It is a known 
> limitation and will eventually be fixed.  For now you can put the 
> executable in a subdirectory:
>
> SUBDIRS(LibDir1 LibDir2 ExeDir)
>
> -Brad
>