From baf26a6ea792f032c27a6853fb375d281e35ffc8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Camilla=20L=C3=B6wy?= <elmindreda@glfw.org>
Date: Sun, 18 Oct 2020 19:34:23 +0200
Subject: [PATCH] Cocoa: Fix ObjC being built as C with CMake 3.19

CMake 3.19 adds -xc when the LANGUAGE file property is C, breaking our
workaround for CMake 3.15 and earlier not understanding the .m suffix.

Fixes #1787.

(cherry picked from commit 3327050ca66ad34426a82c217c2d60ced61526b7)
---
 README.md          | 2 ++
 src/CMakeLists.txt | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index ce29513e..deb2c609 100644
--- a/README.md
+++ b/README.md
@@ -132,6 +132,7 @@ information on what to include when reporting a bug.
    (#1635)
  - [Cocoa] Bugfix: Failing to retrieve the refresh rate of built-in displays
    could leak memory
+ - [Cocoa] Bugfix: Objective-C files were compiled as C with CMake 3.19 (#1787)
  - [X11] Bugfix: IME input of CJK was broken for "C" locale (#1587,#1636)
  - [X11] Bugfix: Xlib errors caused by other parts of the application could be
    reported as GLFW errors
@@ -250,6 +251,7 @@ skills.
  - Konstantin Käfer
  - Eric Larson
  - Francis Lecavalier
+ - Jong Won Lee
  - Robin Leffmann
  - Glenn Lewis
  - Shane Liesegang
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 402f8f6f..e18b14aa 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -72,8 +72,8 @@ if (_GLFW_X11 OR _GLFW_WAYLAND)
     endif()
 endif()
 
-if (APPLE)
-    # For some reason CMake didn't know about .m until version 3.16
+# Workaround for CMake not knowing about .m files before version 3.16
+if ("${CMAKE_VERSION}" VERSION_LESS "3.16" AND APPLE)
     set_source_files_properties(cocoa_init.m cocoa_joystick.m cocoa_monitor.m
                                 cocoa_window.m nsgl_context.m PROPERTIES
                                 LANGUAGE C)