[CMake] Re: How to update a variable inside a subfolder?

[Alan W. Irwin]

On 2007-01-29 22:26+0530 kitts wrote:

> # Here I would like SRC_LST to be updated inside the subdir, however,
> # SRC_LST has the complete list in the subdir not changes made are
> # lost as it returns to this parent directory
> ADD_SUBDIRECTORY(${ARCH})
>
> ADD_LIBRARY(MyLib ${SRC_LST})
>
> The file Source/x86/CMakeLists.txt only contains:
>
> SET(SRC_LIST ${SRC_LIST} arch.c init.S startup.S)
>
> I don't want to include these files directly in Source/CMakeLists.txt as
> file names and the number of them varies from one arch to another. Depending
> on the complexity, they may further contain subfolders for easier code
> organization. Maintainers of the arch specific are different for each arch
> and id like to let them take responsibility with their folders.
>
> The only solution I see is a mechanism in the arch subfolders to create a
> file that will contain names of all the source files for that arch and
> then include that file in the parent folder's CMakeLists.txt. But is
> there a cleaner solution?

Somebody else mentioned using the cache, but if that doesn't work or you
prefer a different approach, then you could simply use cmake modules to set
SRC_LST for each of your possible architectures and then INCLUDE the
appropriate architecture module when needed. That's the approach PLplot
takes when configuring source lists (for various device drivers in our case
rather than various architectures as in your case).  We have a fixed module
directory for our modules (cmake/modules), but you could configure
CMAKE_MODULE_PATH to point to the appropriate architecture dependent module
directory as needed if you prefer to keep your architectures in totally
separate directories.

BTW, my understanding of why variables set in subdirectories do not
propagate to parent directories is the CMake developers are using this rule
to (rightly) limit variable scope to make it more difficult to have
cross-directory bugs.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the Yorick front-end to PLplot (yplot.sf.net); the
Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
__________________________

Linux-powered Science
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