How to make colorized message() with CMake?

I want to have message function in CMakeLists.txt which output colorized text. Maybe an escape sequence.

For example:

message("\x1b[31m;This text must be in red")

It don't work. I got:

Syntax error in cmake code at

/home/taurus/cmakecolor/CMakeLists.txt:1

when parsing string

\x1b[31m;This text must be in red

Invalid escape sequence \x

Solution

To extend @grim's correct answer, you can make things a bit more convenient by setting up variables to handle the various colours:

if(NOT WIN32)
  string(ASCII 27 Esc)
  set(ColourReset "${Esc}[m")
  set(ColourBold  "${Esc}[1m")
  set(Red         "${Esc}[31m")
  set(Green       "${Esc}[32m")
  set(Yellow      "${Esc}[33m")
  set(Blue        "${Esc}[34m")
  set(Magenta     "${Esc}[35m")
  set(Cyan        "${Esc}[36m")
  set(White       "${Esc}[37m")
  set(BoldRed     "${Esc}[1;31m")
  set(BoldGreen   "${Esc}[1;32m")
  set(BoldYellow  "${Esc}[1;33m")
  set(BoldBlue    "${Esc}[1;34m")
  set(BoldMagenta "${Esc}[1;35m")
  set(BoldCyan    "${Esc}[1;36m")
  set(BoldWhite   "${Esc}[1;37m")
endif()

message("This is normal")
message("${Red}This is Red${ColourReset}")
message("${Green}This is Green${ColourReset}")
message("${Yellow}This is Yellow${ColourReset}")
message("${Blue}This is Blue${ColourReset}")
message("${Magenta}This is Magenta${ColourReset}")
message("${Cyan}This is Cyan${ColourReset}")
message("${White}This is White${ColourReset}")
message("${BoldRed}This is BoldRed${ColourReset}")
message("${BoldGreen}This is BoldGreen${ColourReset}")
message("${BoldYellow}This is BoldYellow${ColourReset}")
message("${BoldBlue}This is BoldBlue${ColourReset}")
message("${BoldMagenta}This is BoldMagenta${ColourReset}")
message("${BoldCyan}This is BoldCyan${ColourReset}")
message("${BoldWhite}This is BoldWhite\n\n${ColourReset}")

If you really fancy pushing the boat out, you can replace the built-in message function with your own which colourises the output depending on the message type:

function(message)
  list(GET ARGV 0 MessageType)
  if(MessageType STREQUAL FATAL_ERROR OR MessageType STREQUAL SEND_ERROR)
    list(REMOVE_AT ARGV 0)
    _message(${MessageType} "${BoldRed}${ARGV}${ColourReset}")
  elseif(MessageType STREQUAL WARNING)
    list(REMOVE_AT ARGV 0)
    _message(${MessageType} "${BoldYellow}${ARGV}${ColourReset}")
  elseif(MessageType STREQUAL AUTHOR_WARNING)
    list(REMOVE_AT ARGV 0)
    _message(${MessageType} "${BoldCyan}${ARGV}${ColourReset}")
  elseif(MessageType STREQUAL STATUS)
    list(REMOVE_AT ARGV 0)
    _message(${MessageType} "${Green}${ARGV}${ColourReset}")
  else()
    _message("${ARGV}")
  endif()
endfunction()

message("No colour at all.")
message(STATUS "\"Colour\" is spelled correctly.")
message(AUTHOR_WARNING "\"Color\" is misspelled.")
message(WARNING "Final warning: spell \"color\" correctly.")
message(SEND_ERROR "Game over.  It's \"colour\", not \"color\".")
message(FATAL_ERROR "And there's no \"z\" in \"colourise\" either.")

I can't say that I recommend overriding the built-in message function in this way, but having said that, I've not found any major problems with doing this either.