This document describes the recommended coding style for CMake files in KDE, i.e. CMakeLists.txt files and *.cmake files.
To put in in one sentence: be as careful when writing the CMake files as when you are writing C++ code.
Indent all code correctly, i.e. the body of
Use spaces for indenting, 2, 3 or 4 spaces preferably. Use the same amount of spaces for indenting as is used in the rest of the file. Do not use tabs.
Most important: use consistent upper- or lowercasing within one file !
In general, in KDE the all-lowercase style is preferred.
So, this is recommended:
This is also acceptable:
Mixed casing as shown below works too, but should not be done within KDE:
Add_Executable(hello hello.c) aDd_ExEcUtAbLe(blub blub.c)
To make the code easier to read, use empty commands for endforeach(), endif(), endfunction(), endmacro() and endwhile(). Also, use empty else() commands.
For example, do this:
if(FOOVAR) some_command(...) else() another_command(...) endif()
and not this:
if(BARVAR) some_other_command(...) endif(BARVAR)
You are free to use pkg-config in FindXXX.cmake modules, as long as the following conditions are met:
Follow the style guide from CMake when writing some FindFoo.cmake module: readme.txt
For checking the results inside the Find-module, the macro find_package_handle_standard_args() (coming with CMake) should be used, using the new extended syntax, which supports also version checking.
if(FOO_LIBRARY AND FOO_INCLUDE_DIR) set(FOO_FOUND TRUE) else() ... execute the whole find-logic endif()
should be removed, the find-logic should be executed always. These shortcuts can cause problems e.g. when the same file is used from multiple directories but e.g. with different required versions or components etc.