CMake FAQ
Contents
- 1 General
- 2 Using CMake
- 2.1 Can I build GEOS-Chem Classic and GCHP in the same environment?
- 2.2 How do I build specific targets?
- 2.3 How do I continue a build that was terminated before it finished?
- 2.4 How do I recompile after I make modifications to the source code?
- 2.5 How do I make clean?
- 2.6 How do I change GEOS-Chem's build options?
- 2.7 How do I clean my build's configuration (i.e. CMake's files)?
- 3 Advanced topics
General
What is CMake?
When will CMake support be available?
What are the benefits of CMake?
- You environment is verified before you compile.
- Incremental compiling and a simpler build procedure.
- Fewer wasted HPC jobs due to failed builds.
What is incremental compiling?
What is an "out of source" build?
Using CMake
Can I build GEOS-Chem Classic and GCHP in the same environment?
Yes. Because GEOS-Chem Classic's requirements are a subset of GCHP's.
How do I build specific targets?
Pass the target's name as an argument to make
. You can build multiple specific targets by passing multiple names.
make <name ...>
How do I continue a build that was terminated before it finished?
Run your make
command again. The build system will automatically pick up where it left off.
How do I recompile after I make modifications to the source code?
The build system will automatically figure out what needs to be recompiled when you run make
. There is no need to run "cleaning" commands.
How do I make clean
?
You don't need to do this anymore. When you run a make
command, the build system automatically figures out what needs to be recompiled. A "clean
" target still exists, but it cleans everything.
If you want to restart the build from scratch, you can do
make clean
How do I change GEOS-Chem's build options?
Build options set through CMake variables. You can set CMake variables with -D<name>="<value>"
arguments. Note that "ON", "OFF", "TRUE", "FALSE", etc., are valid booleans in CMake.
cmake . -DFOO="BAR" # set's the variable FOO equal to "BAR"
How do I disable multithreading (i.e. OpenMP)?
cmake . -DOMP=OFF
How do I disable colorized output?
cmake . -DCMAKE_COLOR_MAKEFILE=FALSE
How do I increase the build's verbosity?
cmake . -DCMAKE_VERBOSE_MAKEFILE=TRUE
How do I build for debugging?
cmake . -DCMAKE_BUILD_TYPE=Debug
How do I clean my build's configuration (i.e. CMake's files)?
rm -rf build mkdir build cd build
Advanced topics
Can I use Ninja rather than GNU Make?
Yes. You'll need CMake version 3.7 or greater and Kitware's Ninja distribution (for Fortran futures). To use the Ninja generator rather than the Makefile generator, initialize your build directory with cmake -GNinja <path to source code>
.
Are the environment variables like FC
and ESMF_ROOT
necessary?
No, these are just for convenience. You can configure the build with the standard CMAKE_C_COMPILER
, CMAKE_CXX_COMPILER
, CMAKE_Fortran_COMPILER
, and CMAKE_PREFIX_PATH
variables, rather than environment variables, if you'd prefer. This means GEOS-Chem doesn't impose environment variable requirements on superprojects.