From a575e2cf5eeb8775cdf30ee85a4eda70d2fa4f24 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <sezeroz@gmail.com>
Date: Mon, 17 Jan 2022 20:56:24 +0300
Subject: [PATCH] Enable alloca on mingw/cygwin builds:

This effectively reverts commit 391d73e37b26614e2e343ca8e9d4334e07380896
Fixes https://github.com/libsdl-org/SDL/issues/5234
---
 CMakeLists.txt | 4 +---
 configure.ac   | 8 +-------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index efaa9e34d..a6a8a0029 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -855,9 +855,7 @@ if(SDL_LIBC)
       string(TOUPPER ${_FN} _UPPER)
       set(HAVE_${_UPPER} 1)
     endforeach()
-    if(NOT CYGWIN AND NOT MINGW)
-      set(HAVE_ALLOCA 1)
-    endif()
+    set(HAVE_ALLOCA 1)
     set(HAVE_M_PI 1)
     target_compile_definitions(sdl-build-options INTERFACE "-D_USE_MATH_DEFINES") # needed for M_PI
     set(STDC_HEADERS 1)
diff --git a/configure.ac b/configure.ac
index b60a1638c..5728ed34d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -318,13 +318,7 @@ dnl Check for typedefs, structures, etc.
 dnl Check for defines
     AC_CHECK_DEFINE(M_PI, math.h)
 
-    case "$host" in
-    *-*-cygwin* | *-*-mingw*)
-        ;;
-    *)
-        AC_FUNC_ALLOCA
-        ;;
-    esac
+    AC_FUNC_ALLOCA
 
 dnl Checks for library functions.
     AC_FUNC_MEMCMP