Provided by: libsdl3-doc_3.2.20+ds-2_all 

NAME
SDL_PLATFORM_OS2 - A preprocessor macro that is only defined if compiling for OS/2.
SYNOPSIS
#include <SDL3/SDL_platform_defines.h>
#define SDL_PLATFORM_OS2 1
AVAILABILITY
This macro is available since SDL 3.2.0.
Simple Directmedia Layer SDL 3.2.20 SDL_PLATFORM_OS2(3)