deps/libchdr/deps/zstd-1.5.5/build/cmake/README.md

   1 # Cmake contributions
   2
   3 Contributions to the cmake build configurations are welcome. Please
   4 use case sensitivity that matches modern (i.e. cmake version 2.6 and above)
   5 conventions of using lower-case for commands, and upper-case for
   6 variables.
   7
   8 ## How to build
   9
  10 As cmake doesn't support command like `cmake clean`, it's recommended to perform an "out of source build".
  11 To do this, you can create a new directory and build in it:
  12 ```sh
  13 cd build/cmake
  14 mkdir builddir
  15 cd builddir
  16 cmake ..
  17 make
  18 ```
  19 Then you can clean all cmake caches by simply delete the new directory:
  20 ```sh
  21 rm -rf build/cmake/builddir
  22 ```
  23
  24 And of course, you can directly build in build/cmake:
  25 ```sh
  26 cd build/cmake
  27 cmake
  28 make
  29 ```
  30
  31 To show cmake build options, you can:
  32 ```sh
  33 cd build/cmake/builddir
  34 cmake -LH ..
  35 ```
  36
  37 Bool options can be set to `ON/OFF` with `-D[option]=[ON/OFF]`. You can configure cmake options like this:
  38 ```sh
  39 cd build/cmake/builddir
  40 cmake -DZSTD_BUILD_TESTS=ON -DZSTD_LEGACY_SUPPORT=OFF ..
  41 make
  42 ```
  43
  44 ### referring
  45 [Looking for a 'cmake clean' command to clear up CMake output](https://stackoverflow.com/questions/9680420/looking-for-a-cmake-clean-command-to-clear-up-cmake-output)
  46
  47 ## CMake Style Recommendations
  48
  49 ### Indent all code correctly, i.e. the body of
  50
  51  * if/else/endif
  52  * foreach/endforeach
  53  * while/endwhile
  54  * macro/endmacro
  55  * function/endfunction
  56
  57 Use spaces for indenting, 2, 3 or 4 spaces preferably. Use the same amount of
  58 spaces for indenting as is used in the rest of the file. Do not use tabs.
  59
  60 ### Upper/lower casing
  61
  62 Most important: use consistent upper- or lowercasing within one file !
  63
  64 In general, the all-lowercase style is preferred.
  65
  66 So, this is recommended:
  67
  68 ```
  69 add_executable(foo foo.c)
  70 ```
  71
  72 These forms are discouraged
  73
  74 ```
  75 ADD_EXECUTABLE(bar bar.c)
  76 Add_Executable(hello hello.c)
  77 aDd_ExEcUtAbLe(blub blub.c)
  78 ```
  79
  80 ### End commands
  81 To make the code easier to read, use empty commands for endforeach(), endif(),
  82 endfunction(), endmacro() and endwhile(). Also, use empty else() commands.
  83
  84 For example, do this:
  85
  86 ```
  87 if(FOOVAR)
  88    some_command(...)
  89 else()
  90    another_command(...)
  91 endif()
  92 ```
  93
  94 and not this:
  95
  96 ```
  97 if(BARVAR)
  98    some_other_command(...)
  99 endif(BARVAR)
 100 ```
 101
 102 ### Other resources for best practices
 103
 104 https://cmake.org/cmake/help/latest/manual/cmake-developer.7.html#modules