This page will explain how to manually create a CMakeLists.txt file to link a custom program with CGAL. A base can be created using the script cgal_create_CMakeLists. Its usage is detailed in Section Creating a CMake Script for a Program Using CGAL. 
Linking with CGAL
To link with the CGAL library, use the following: 
add_executable(my_executable my_source_file.cpp)
target_link_libraries(my_executable CGAL::CGAL)
 Other CGAL libraries are linked similarly. For example, with CGAL_Core:
find_package(
CGAL REQUIRED COMPONENTS Core)
 
target_link_libraries(my_executable CGAL::CGAL CGAL::CGAL_Core)
There are also imported targets to link with CGAL dependencies that can be found in the section Essential and Optional Third Party Dependencies.
- Note
 - The CGAL targets define the following compiler flags:
-frounding-math with gcc 
/fp:strict /fp:except- with MSVC 
 
Minimal Example Using Qt5
This section describes a minimal example of a program that uses CGAL and Qt5 for some GUI features.
CMakeLists.txt
 # Created by the script cgal_create_cmake_script
# This is the CMake script for compiling a CGAL application.
 
 
cmake_minimum_required(VERSION 3.1...3.15)
project( Surface_mesh_Examples )
 
if(POLICY CMP0053)
  # Only set CMP0053 to OLD with CMake<3.10, otherwise there is a warning.
  if(NOT POLICY CMP0070)
    cmake_policy(SET CMP0053 OLD)
  else()
    cmake_policy(SET CMP0053 NEW)
  endif()
endif()
 
if(POLICY CMP0071)
    cmake_policy(SET CMP0071 NEW)
endif()
 
#CGAL_Qt5 is needed for the drawing.
find_package(
CGAL REQUIRED OPTIONAL_COMPONENTS Qt5)
 
 
if(CGAL_Qt5_FOUND)
  #required to use basic_viewer
  add_definitions(-DCGAL_USE_BASIC_VIEWER -DQT_NO_KEYWORDS)
endif()
 
if ( CGAL_FOUND )
  #create the executable of the application
 
  create_single_source_cgal_program("draw_surface_mesh.cpp")
  if(CGAL_Qt5_FOUND )
 
    #link it with the required CGAL libraries
 
    target_link_libraries(draw_surface_mesh PUBLIC CGAL::CGAL_Qt5)
  endif()
 
else()
 
    message(STATUS "This program requires the 
CGAL library, and will not be compiled.")
 
 
endif()
#end of the file
draw_surface_mesh.cpp
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/draw_surface_mesh.h>
#include <fstream>
 
 
int main(int argc, char* argv[])
{
  Mesh sm1;
  std::ifstream in1((argc>1)?argv[1]:"data/elephant.off");
  in1 >> sm1;
 
 
  return EXIT_SUCCESS;
}