CMake tutorial, explain build configurations

[cppuser1234]

hello community,

I am following the CMake book to learn about CMake. I have trouble to follow chapter 3: build configurations (https://riptutorial.com/cmake/example/26702/setting-a-release-debug-configuration)

In this part it is not very clear why these configurations are used, and how they work.

here is the script in cmake:

CMAKE_MINIMUM_REQUIRED(VERSION 2.8.11)
SET(PROJ_NAME "myproject")
PROJECT(${PROJ_NAME})

# Configuration types
SET(CMAKE_CONFIGURATION_TYPES "Debug;Release" CACHE STRING "Configs" FORCE)
IF(DEFINED CMAKE_BUILD_TYPE AND CMAKE_VERSION VERSION_GREATER "2.8")
  SET_PROPERTY(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS  ${CMAKE_CONFIGURATION_TYPES})
ENDIF()

SET(${PROJ_NAME}_PATH_INSTALL     "/opt/project"                     CACHE PATH "This directory contains installation Path")
SET(CMAKE_DEBUG_POSTFIX "d")

# Install
#---------------------------------------------------#
INSTALL(TARGETS ${PROJ_NAME}
    DESTINATION  "${${PROJ_NAME}_PATH_INSTALL}/lib/${CMAKE_BUILD_TYPE}/"
    )

So, instead of building the project relative to my project folder, it installs into "/opt/" directory in linux. Why would I want to do that? And what if I am working with Windows, instead?

Since the application is build in "/opt/" isn't this similar to an installer for my software? When should I prefer to do that?

Should I use this concept also if I want relative path for debug/release directories like in Eclipse?


thank you!

[helios]

It's not "wrong" to ask this question here, but you may get better answers in one of the CMake mailing lists: https://cmake.org/mailing-lists/