From 02c874717648f1dd919eca9c39a8b2b0ebc73657 Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <anonymous.maarten@gmail.com>
Date: Wed, 27 Jul 2022 15:05:41 +0200
Subject: [PATCH] math.h does not always provide M_PI

This fixes the following error when building with SDL_LIBC:
SDL\test\testautomation_math.c(1965): error C2065: 'M_PI': undeclared identifier
---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f2eec85cd..8fc50afcd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -929,7 +929,7 @@ if(SDL_LIBC)
       set(HAVE_${_UPPER} 1)
     endforeach()
     set(HAVE_ALLOCA 1)
-    set(HAVE_M_PI 1)
+    check_symbol_exists(M_PI math.h HAVE_M_PI)
     target_compile_definitions(sdl-build-options INTERFACE "-D_USE_MATH_DEFINES") # needed for M_PI
     set(STDC_HEADERS 1)
   else()