Key Concepts (Mastering CMake)

1 Key Concepts (Mastering CMake)

1.1 Main Structures

Keyword

targets, generators and commands, etc.

Source files -> Targets [EXE|LIB]

Directory, Local Generator, Global Generator

Main Structure

1) cmake

1. controls the cmake process
2. can be created and used in various GUIs

2) cmake has one cmGlobalGenerator

1. abstract base class
2. child classes responsible for platform-specific build process

3) cmGlobalGenerator has many cmLocalGenerator

1. abstract base class
2. child classes responsible for platform-specific build file generation

4) cmLocalGenerator has one cmMakefile

Parse CMakeLists.txt and store information from CMakeLists.txt file

1. List of targets and variables
2. Optional flags
3. List of libaries
4. List of include pathes

5) cmCommand

1. abstract base class
2. child classes responsible for implementing all commands in CMake

1.2 Targets

add_library, add_executable and add_custom_target

EX#1

add_library (foo STATIC foo1.c foo2.c)

EX#2

add_library (foo foo.cxx)target_link_libraries (foo bar)add_executable (foobar foobar.cxx)target_link_libraries (foobar foo)

1.3 Source Files [TODO]

1.4 Directories, Generators, Tests, and Properties [TODO]

1.5 Variables and Cache Entries [TODO]

EX#1 Control Flow

set (FOO 1)if (${FOO} LESS 2)    set (FOO 2)else (${FOO} LESS 2)    set (FOO 3)endif (${FOO} LESS 2)

EX#2 Var Scope

function (foo)  message (${test}) # test is 1 here  set (test 2)  message (${test})endfunction()set (test 1)foo()message (${test})

EX#3 Parent Scrope

function (foo)  message (${test})  set (test 2 PARENT_SCOPE)  message (${test)}endfunction()set (test 1)foo()message (${test}) # test will now be 2 here

EX#4 List

set (items_to_buy apple orange pear bear)foreach (item ${items_to_buy})  message ("Don't forget to buy one ${item}")endforeach()

EX#5 Option

option (USE_JPEG "Do you want to use the JPEG library")

or

set (USE_JPEG ON CACHE BOOL "include jpge support?")

TYPES: BOOL, PATH, FILEPATH, STRING

1.6 CheatSheet

1.6.1 Useful command:

include_directoriesadd_subdirectoryadd_libraryadd_executabletarget_link_librariesfind_package

1.6.1.1 Generate && Build

Case#1 Visual Studio Win64

>> cd build>> cmake -G "Visual Studio 14 2015 Win64" ..>> cmake --build .

Case#2 Visual Studio Win32

>> cd build>> cmake -G "Visual Studio 14 2015" ..>> cmake --build .

Case#3 Build Specific Target

>> cmake --build . --target HelloWorld

1.7 Reference

[1] CMake 3.0.2 Documetation