From 7bbff520a047170bd9fadae0304ce3e8c07f984b Mon Sep 17 00:00:00 2001
From: Chris Hennes <chennes@pioneerlibrarysystem.org>
Date: Thu, 4 Mar 2021 14:44:44 -0600
Subject: [PATCH] Modify Python checks when cMake >= 3.12

---
 cMake/FreeCAD_Helpers/SetupPython.cmake       | 32 +++++++++++--------
 .../SetupShibokenAndPyside.cmake              |  2 +-
 src/Mod/Measure/App/CMakeLists.txt            |  2 +-
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/cMake/FreeCAD_Helpers/SetupPython.cmake b/cMake/FreeCAD_Helpers/SetupPython.cmake
index fdf9952490..59882b1ef3 100644
--- a/cMake/FreeCAD_Helpers/SetupPython.cmake
+++ b/cMake/FreeCAD_Helpers/SetupPython.cmake
@@ -123,21 +123,27 @@ macro(SetupPython)
         else (NOT DEFINED PYTHON_VERSION_STRING)
             find_package(PythonLibs ${PYTHON_VERSION_STRING} EXACT)
         endif(NOT DEFINED PYTHON_VERSION_STRING)
+        if(NOT PYTHONLIBS_FOUND)
+            message(FATAL_ERROR "=================================\n"
+                                "Python not found, install Python!\n"
+                                "=================================\n")
+        endif()
     else()
-        find_package(Python3 COMPONENTS Interpreter Development)
+        find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
+
+        # For compatibility with old CMake scripts
+        set(PYTHON_LIBRARIES ${Python3_LIBRARIES})
+        set(PYTHON_INCLUDE_DIRS ${Python3_INCLUDE_DIRS})
+        set(PYTHON_LIBRARY_DIRS ${Python3_LIBRARY_DIRS})
+        set(PYTHON_VERSION_STRING ${Python3_VERSION})
+        set(PYTHON_VERSION_MAJOR ${Python3_VERSION_MAJOR})
+        set(PYTHON_VERSION_MINOR ${Python3_VERSION_MINOR})
+        set(PYTHON_VERSION_PATCH ${Python3_VERSION_PATCH})
     endif()
     
-    if(NOT PYTHONLIBS_FOUND)
-        message(FATAL_ERROR "=================================\n"
-                            "Python not found, install Python!\n"
-                            "=================================\n")
-    else(NOT PYTHONLIBS_FOUND)
-        # prevent python3 lower than 3.6 (not enough utf8<->unicode tools)
-        if(PYTHON_VERSION_MAJOR EQUAL 3)
-            if(PYTHON_VERSION_MINOR LESS 6)
-                message(FATAL_ERROR "To build FreeCAD you need at least Python 3.6\n")
-            endif(PYTHON_VERSION_MINOR LESS 6)
-        endif(PYTHON_VERSION_MAJOR EQUAL 3)
-    endif(NOT PYTHONLIBS_FOUND)
+    # prevent python3 lower than 3.6
+    if (${PYTHON_VERSION_STRING} VERSION_LESS "3.6")
+         message(FATAL_ERROR "To build FreeCAD you need at least Python 3.6\n")
+    endif()
 
 endmacro(SetupPython)
diff --git a/cMake/FreeCAD_Helpers/SetupShibokenAndPyside.cmake b/cMake/FreeCAD_Helpers/SetupShibokenAndPyside.cmake
index 00890e14f7..2824af9c81 100644
--- a/cMake/FreeCAD_Helpers/SetupShibokenAndPyside.cmake
+++ b/cMake/FreeCAD_Helpers/SetupShibokenAndPyside.cmake
@@ -15,7 +15,7 @@ macro(SetupShibokenAndPyside)
     if (Shiboken2_FOUND)
         # Shiboken2 config file was found but it may use the wrong Python version
         # Try to get the matching config suffix and repeat finding the package
-        set(SHIBOKEN_PATTERN .cpython-${PYTHON_VERSION_MAJOR}${PYTHON_VERSION_MINOR})
+        set(SHIBOKEN_PATTERN .cpython-${Python3_VERSION_MAJOR}${Python3_VERSION_MINOR})
 
         file(GLOB SHIBOKEN_CONFIG "${Shiboken2_DIR}/Shiboken2Config${SHIBOKEN_PATTERN}*.cmake")
         if (SHIBOKEN_CONFIG)
diff --git a/src/Mod/Measure/App/CMakeLists.txt b/src/Mod/Measure/App/CMakeLists.txt
index 43ba5f8fa3..1640f52682 100644
--- a/src/Mod/Measure/App/CMakeLists.txt
+++ b/src/Mod/Measure/App/CMakeLists.txt
@@ -12,7 +12,7 @@ include_directories(
     ${Boost_INCLUDE_DIRS}
     ${OCC_INCLUDE_DIR}
     ${ZLIB_INCLUDE_DIR}
-    ${PYTHON_INCLUDE_PATH}
+    ${Python3_INCLUDE_DIRS}
     ${XERCESC_INCLUDE_DIR}
 )
 link_directories(${OCC_LIBRARY_DIR})