[Cmake] variables set in SUBDIRS() available to top-level CMakeList?

[Zachary Pincus]

Bill, thanks for your reply.

I'm trying to collect a list of values (generated by CMakeLists in each 
subdirectory) into a single cache variable that then gets processed by 
the top-level CMakeList.

I've run into one difficulty here:

First, CACHE variables are retained between cmake configuration runs. 
So if I have each CMakeLists in each subdirectory append a value to a 
single cache variable, then each time I re-configure, that variable 
grows longer and longer.

This is of course totally reasonable. However, it isn't the behavior I 
want, so I tried something like this:

SET(Accumulator "")
SUBDIRS(foo bar baz)

where the CMakeLists in foo, bar, and baz all add information to the 
end of Accumulator.

This breaks everything: now "Accumulator" gets cleared after EACH 
subdir is processed.
Why does CMAKE appear to be running the SET(Accumulator "") after each 
subdir is processed?
Is there any way to circumvent this behavior, and only clear the 
variable ONCE each configuration run?

Thanks,

Zach Pincus

Department of Biochemistry and Program in Biomedical Informatics
Stanford University School of Medicine

On Apr 13, 2004, at 5:40 AM, William A. Hoffman wrote:

> Subdir variables and commands do not affect the parent directories.
> In the hello example, it sets the directories for the whole project at
> the top.   You could and should only set the include directories where
> they are needed.  The only way to pass information up to a parent 
> directory
> is via CACHE variables which once set are available to the entire 
> project.
>
> -Bill
>
>
> At 03:29 PM 4/9/2004, Zachary Pincus wrote:
>> Hello,
>>
>> If a CMakeLists file called via SUBDIRS(...) sets some variables, are 
>> these available to commands in the top-level file?
>>
>> For example, I have a simple project which builds a library and an 
>> executable.
>>
>> Top Level CMakeLists:
>> PROJECT(foo)
>> SUBDIRS(./lib)
>> ...
>>
>> Lib CMakeLists:
>> INCLUDE_DIRECTORIES(./headers)
>>
>> So, will commands in the top level cmakelists subsequent to the 
>> subdirs() call be able to see the INCLUDE_DIRECTORIES set in the 
>> lower-level cmakelist? If so, will the relative path be properly 
>> translated, or would I have to be more careful in setting the address 
>> as relative to the upper-level project root? (Is there a way to get 
>> the path to the current directory, relative to the project root, from 
>> cmake?)
>>
>> I ask this because doing things this way seems more robust than the 
>> method here:
>> http://cmake.org/HTML/Examples.html
>> where one sets the INCLUDE_DIRECTORIES for the headers in the "hello" 
>> directory NOT in the "hello" CMakeLists file, but in a CMakeLists 
>> outside of the "hello" directory. It seems like it would be nicer to 
>> set every variable relevant to a given directory in that directory's 
>> CMakeLists file, so that changes to a directory structure necessitate 
>> editing only one CMakeLists file.
>>
>> Thanks,
>>
>> Zach Pincus
>>
>> Department of Biochemistry and Program in Biomedical Informatics
>> Stanford University School of Medicine
>>
>> _______________________________________________
>> Cmake mailing list
>> Cmake at www.cmake.org
>> http://www.cmake.org/mailman/listinfo/cmake
>
> _______________________________________________
> Cmake mailing list
> Cmake at www.cmake.org
> http://www.cmake.org/mailman/listinfo/cmake
>