[CMake] Compiling all .o files in one directory

[Brantner Matthias]

Hello,

the source files of our C++ project are distributed among many  
directories being on different levels.
Each directory contains a CMakeLists.txt file that defines a variable  
which contains all .cpp files
from this directory. In order to collect all .cpp files from all  
directories, we include each
CMakeLists.txt file in its parent directory and prefix the path of  
each file with its directory name.
On the top-level (i.e. our src directory), we create a library  
consisting of all compiled .cpp files.

The approach mentioned above is described in "Mastering CMake" (see  
Sec. 5.1 on Page 61).
Most of the time, our programmers work on a single file or on multiple  
files in one directory and use
the CMake Makefile generator.
I already found out that when changing into the build/src directory, I  
can compile/preprocess/ar single
files using "make path/file.o/.i/.s".

My question is, whether there is a way or you have an idea how to  
build all object files in one directory
(instead of the complete library) with one command, for example using  
"make path". This would be a really
helpful shortcut.

Thank you very much in advance.

Best regards,

Matthias Brantner