This a really short and compact introduction to CMake mechanisum and common variables used. Showed in a simple groupe meeting of the REVES team of the INRIA Sophia Antipolis (France) to sudents/PhD.

1. CMake introduction

2. 1- PRINCIPLES AND POTENTIALS
1.1- INTRO
1.2- WORKFLOW
2- CROSSPLATEFORM USAGES
2.1- USEFUL VARIABLES AND USE
2.2- GUI AND CACHE
3- FIND PACKAGE
4- ADVANCED AND MORE
5- INSTALLATION, EXPORT, PACKAGE
(NOT PRESENTED HERE)
jerome.esnault@inria.fr 02 July 2014 - 2

3. 1- Principles and potentials
1.1- Intro
• Objectif :
Crossplateform toolbox (linux/windows/mac) to help to the build / creation /
compilation of C/C++ projects.
• Usage :
Hight level of script language
• Generation :
Files which are used for the chosen developement environnement in the current
platform
• Developped by KitWare in open source version and started in 1999 for ITK
projects then used by VTK project.
• At this moment at 3.0 version and used by many big projects like OGRE,
OpenSceneGraph…
http://www.ohloh.net/p/cmake?ref=sample
jerome.esnault@inria.fr 02 July 2014 - 3

4. 1- Principles and potentials
CMake / Ctest / CPack
Compiler
jerome.esnault@inria.fr 02 July 2014 - 4
Modules
CMake
[*.cmake]
[*.in]
Sources C/C++/Java CMakeLists.txt / Ctest scripts
CMakeCache.txt
Native build system files [MakeFiles, sln…]
Targets [executables, libraries, plugins]
1.2- Workflow

5. 2- CROSSPLATEFORM USAGES
Cmake [options] <path-to-source>
$ cd projectName
$ mkdir build && cd build
$ cmake ..
$ make install
$ cd projectName
$ mkdir build && cd build
$ cmake-gui ..
$ make install
Generators / IDE compatibilities :
• Borland
• MinGW
• Nmake
• Unix
• Visual Studio 6/7/8/9/10/11
• Xcode
• codeBlocks
• Eclipse
• QtCreator
3 tree structures :
• CMAKE_SOURCE_DIR
• CMAKE_BINARY_DIR
• CMAKE_INSTALL_PREFIX
OR
jerome.esnault@inria.fr 02 July 2014 - 5

6. 2- CROSSPLATEFORM USAGES
2.1- Useful variables and use CMake_presentation
CMAKE_SOURCE_DIR CMAKE_BINARY_DIR CMAKE_INSTALL_PREFIX
rootFolder
CMakeLists.txt
Cmake_minimum_required(VERSION 2.8)
Project(foo)
…
Add_subdirectory(subFolder1)
…
subFolder1
CMakeLists.txt
build
Same structure
but with generated
or temp files
Project(bar)
…
Add_executable(myApp mySources)
subFolder2
CMakeLists.txt
CMAKE_CURRENT_SOURCE_DIR CMAKE_CURRENT_BINARY_DIR
(=subFolder2)
CMakeFiles
Structure defined by
‘install()’ cmake
instruction
jerome.esnault@inria.fr 02 July 2014 - 6

7. 2- CROSSPLATEFORM USAGES
2.1- Useful variables and use CMake_Useful_Variables
CMAKE_SOURCE_DIR
(=path to rootFolder)
CMAKE_BINARY_DIR
(=path to build)
CMAKE_PROJECT_NAME (=foo) CMAKE_LIBRARY_OUTPUT_DIRECTORY
CMAKE_ARCHIVE_OUTPUT_DIRECTORY
CMAKE_RUNTIME_OUTPUT_DIRECTORY
PROJECT_NAME (=bar)
UNIX WIN32 APPLE
MSVC
jerome.esnault@inria.fr 02 July 2014 - 7
bool
Place where target name will be generated, see:
Add_executable(name sources)
Add_library(name srouces [STATIC|SHARED])

8. 2- CROSSPLATEFORM USAGES
2.1- Useful variables and use
CMake instructions act on :
• new project / sub-project creations
CMake_Wiki
• cmake variables and list (cached or not)
(content of a cmake variableis ${myCmakeVar})
• system file manipulation
• building out of source, installation and packaging an installer
• the « automatique » research of dependencies package
and files
• the cmake function and macros creation (for reusable code)
• the customization of target properties
or systeme file properties
Project(…)
Add_subdirectory(…)
Add_dependencies(…)
Include_directories(…)
Target_link_libraries(…)
Set(…) – unset(…)
List(…)
Option(…)
Foreach() … endforeach()
If() … else() … endif()
File(…) - String(…)
Configure_file(…)
Install(…)
Find_package(…)
Find_library(…)
Find_file(…) – Find_path(…)
Include(…)
Function()…endfunction()
Macro()…endmacro()
Add_definition(…)
Define_property(…)
jerome.esnault@inria.fr 02 July 2014 - 8

9. 2- CROSSPLATEFORM USAGES
2.2- GUI and CACHE
CMAKE_BINARY_DIR
(=path to build)
CMakeCache.txt
Foo.sln
Cmake generated
or temp files
jerome.esnault@inria.fr 02 July 2014 - 9

10. 2- CROSSPLATEFORM USAGES
QUESTION ?
EXAMPLES with current IBR projects,
Showing differences between
spixel_warp
Ulrvr
Ibr_common
jerome.esnault@inria.fr 02 July 2014 - 10

11. 3- Find Package
3.1- How to use
CMake_find
find_package(<package> [version] [EXACT] [QUIET]
[REQUIRED] [[COMPONENTS] [components...]]
[CONFIG|NO_MODULE]
[NO_POLICY_SCOPE]
[NAMES name1 [name2 ...]]
[CONFIGS config1 [config2 ...]]
[HINTS path1 [path2 ... ]]
[PATHS path1 [path2 ... ]]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[NO_DEFAULT_PATH]
[NO_CMAKE_ENVIRONMENT_PATH]
[NO_CMAKE_PATH]
[NO_SYSTEM_ENVIRONMENT_PATH]
[NO_CMAKE_PACKAGE_REGISTRY]
[NO_CMAKE_BUILDS_PATH]
[NO_CMAKE_SYSTEM_PATH]
[NO_CMAKE_SYSTEM_PACKAGE_REGISTRY]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH])
2 ways :
1. With a Find<package>.cmake module file
2. With a cmake config file provided by the dependency
jerome.esnault@inria.fr 02 July 2014 - 11

12. 3- Find Package
3.1- How to use
CMake_find
2 ways :
1. With a Find<package>.cmake module file
find_package (foo) Will look for Findfoo.cmake into : 1- CMAKE_MODULE_PATH list of dirs if not empty
2- ${CMAKE_ROOT}/Modules
The objective of a Findfoo.cmake try to locate libraries and includes files (and executables) to
let user then use cmake variable to abstract paths and names whatever is the platform.
Findfoo.cmake may use :
find_library (<VAR> name1 [path1 path2 ...])
find_path (<VAR> name1 [path1 path2 ...])
find_file (<VAR> name1 [path1 path2 ...])
find_program (<VAR> name1 [path1 path2 ...])
FIND_PACKAGE_HANDLE_STANDARD_ARGS(<name>
Paths may be set using :
* foo_DIR cmake variable
* $ENV{name} cmake variable
* [HKEY_LOCAL_MACHINE …]
(DEFAULT_MSG|"Custom failure message") <var1>...<varN> )
For find_* cmake instructions, some additional global list of dirs may be set with :
CMAKE_INCLUDE_PATH
CMAKE_LIBRARY_PATH
CMAKE_PREFIX_PATH
jerome.esnault@inria.fr 02 July 2014 - 12

13. 3- Find Package
3.1- How to use
CMake_find
2 ways :
1. With a Find<package>.cmake module file
Inside Findfoo.cmake, we have some ‘ready to use’ cmake variable according to the
arguments passed to the find_package(…), for example :
foo_FIND_REQUIRED if REQUIRED was given
foo_FIND_COMPONENTS list if COMPONENTS was given with list of modules to find
EXAMPLES OR QUESTION ?
See standard FindOpenAL.cmake or FindGDAL.cmake
for simple examples.
See standard FindBoost.cmake or FindQt4.cmake for
complexe examples.
jerome.esnault@inria.fr 02 July 2014 - 13

14. 3- Find Package
3.1- How to use
CMake_find
2 ways :
2. With a cmake config file provided by the dependency
The 3rdParty project may provide a cmake config file which was generated by
cmake on installation time (using the EXPORT command)
On your side, if no Findfoo.cmake was found, cmake try to locate instead :
fooConfig.cmake or foo-config.cmake file (as you need at least to provide foo_DIR
which point to this file).
For advanced cmake user,
Should be discussed latter.
jerome.esnault@inria.fr 02 July 2014 - 14

15. 4- ADVANCED AND MORE
For compiler command line:
CMAKE_CXX_FLAGS cmake var
For preprocessors :
add_definitions(-DFOO -DBAR ...)
configure_file(<input> <output>
For more examples:
suitesparse-metis-for-windows
[COPYONLY] [ESCAPE_QUOTES] [@ONLY]
[NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF] ])
For custom targets :
add_custom_target(Name [ALL] [command1 [args1...]]
[COMMAND command2 [args2...] ...]
[DEPENDS depend depend depend ... ]
[WORKING_DIRECTORY dir]
[COMMENT comment] [VERBATIM]
[SOURCES src1 [src2...]])
For installation (see doxygen example) :
Install(…) (multiples signatures)
jerome.esnault@inria.fr 02 July 2014 - 15

16. 5-INSTALLATION, EXPORT, PACKAGE
TIPS here
And here
jerome.esnault@inria.fr 02 July 2014 - 16

17. ANDROID && iOS toolchain
• ANDROID : https://github.com/taka-no-me/android-cmake
• iOS : https://code.google.com/p/ios-cmake/
• Global integration with Qt and QtCreator topic :
(http://qt-project.org/forums/viewthread/36359)
jerome.esnault@inria.fr 02 July 2014 - 17