SDL: Add QNX as a platform to the cmake build files

From b47eeb84886add3e181918b221bb6dae2593edc1 Mon Sep 17 00:00:00 2001
From: Elad Lahav <[EMAIL REDACTED]>
Date: Fri, 6 Jan 2023 08:24:18 -0500
Subject: [PATCH] Add QNX as a platform to the cmake build files

---
 cmake/sdlchecks.cmake   | 2 ++
 cmake/sdlplatform.cmake | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/cmake/sdlchecks.cmake b/cmake/sdlchecks.cmake
index b7061ec23897..784eb8e6e208 100644
--- a/cmake/sdlchecks.cmake
+++ b/cmake/sdlchecks.cmake
@@ -807,6 +807,8 @@ macro(CheckPTHREAD)
     elseif(EMSCRIPTEN)
       set(PTHREAD_CFLAGS "-D_REENTRANT -pthread")
       set(PTHREAD_LDFLAGS "-pthread")
+    elseif(QNX)
+      # pthread support is baked in
     else()
       set(PTHREAD_CFLAGS "-D_REENTRANT")
       set(PTHREAD_LDFLAGS "-lpthread")
diff --git a/cmake/sdlplatform.cmake b/cmake/sdlplatform.cmake
index 5cf31457cd4f..4524867ded47 100644
--- a/cmake/sdlplatform.cmake
+++ b/cmake/sdlplatform.cmake
@@ -54,6 +54,8 @@ macro(SDL_DetectCMakePlatform)
     set(SDL_CMAKE_PLATFORM Android)
   elseif(CMAKE_SYSTEM_NAME MATCHES "Emscripten.*")
     set(SDL_CMAKE_PLATFORM Emscripten)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "QNX.*")
+    set(SDL_CMAKE_PLATFORM QNX)
   elseif(CMAKE_SYSTEM_NAME MATCHES "BeOS.*")
     message_error("BeOS support has been removed as of SDL 2.0.2.")
   endif()