Invoking make install on a subdirectory before make all - cmake

Question

I am working on migrating a C++ project whose configuration currently is a combination of cmake (CMakeLists.txt) and Make (GNUmakefile), to using only cmake. The way it's currently set is:
myproject
| CMakeLists.txt (add_subdirectory(src))
| src/
| apps/
| myapp/
| [myapp source files]
| GNUmakefile
| ...
| libs/
| mylib/
| [mylib source files]
| GNUmakefile
| ...
| common/
| CMakeLists.txt (add_subdirectory(dir1, dir2, dir3...))
| ...
| include/
There are more apps and libs outside of myapp and mylib, but they all build and link in similar ways, so if I have one, I can get all.
The way the project builds right now, there is a script that essentially has 4 lines:
cmake path/to/myproject // with the necessary flags and variables passed
make all DESTDIR=$INSTALL_DIR install
cd src/libs ; make all
cd src/apps ; make all
This works because common, which has no dependencies, builds and installs first (include also gets installed here), then libs - which depends on common - builds, and then apps - which depends on both libs and common - builds.
My problem is, if I replace the GNUmakefiles in libs and apps, I don't know how to change the commands I run in the build script so that cmake and make are interwoven like so:
cmake configures common
make compiles & installs all the cmake targets from common (let's say those are libcommon.so and libcommonutils.so)
cmake configures libs
make compiles & installs all the cmake targets from libs (which uses the libraries from common to produce mylib.a)
cmake configures apps
make compiles & installs all the cmake targets from apps (which uses mylib.a and the common shared libraries)
Installing include will also have to happen at some point, early on, since common depends on the header files inside it.
An alternative solution might also work, of course, but this (interweaving cmake and make calls) is the only one I could think of.

Answer 1

You can use ExternalProject_add for common, libs and apps.
src/CMakeLists.txt:
ExternalProject_add(common
SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/common
BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/common
# Forward CMAKE_INSTALL_PREFIX to external project.
CMAKE_CACHE_ARGS -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_INSTALL_PREFIX}
)
ExternalProject_add(libs
SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/libs
BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/libs
# Disable *install* step
INSTALL_COMMAND ""
)
ExternalProject_add(apps
SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/apps
BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/apps
# Disable *install* step
INSTALL_COMMAND ""
)
# Adjust dependencies between components
add_dependencies(libs common)
add_dependencies(apps libs common)
Usage of this script(out-of-source build; in-source build is also supported)
cmake -DCMAKE_INSTALL_PREFIX=<install-dir> <source-dir>
make
is equvalent to the following sequence of commands:
mkdir src/common && cd src/common \
&& cmake -DCMAKE_INSTALL_PREFIX=<install-dir> <source-dir>/src/common && make install
mkdir src/libs && cd src/libs && cmake <source-dir>/src/libs && make all
mkdir src/apps && cd src/apps && cmake <source-dir>/src/apps && make all
Processing of include is not implemented, but you may do that in similar way.