there is no 'dealloca' in stb_vorbis: we need alloca().

also, if HAVE_LIBC is defined, alloca -> SDL_stack_alloc definition used to become a chicken-egg problem...
icculus · Mar 15, 2021 · cd752f6 · cd752f6
1 parent 37223b0
commit cd752f6
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Showing 2 changed files with 18 additions and 14 deletions.
diff --git a/src/SDL_sound_vorbis.c b/src/SDL_sound_vorbis.c
@@ -43,9 +43,6 @@
 #ifdef memcpy
 #undef memcpy
 #endif
-#ifdef alloca
-#undef alloca
-#endif
 #define assert SDL_assert
 #define memset SDL_memset
 #define memcmp SDL_memcmp
@@ -56,8 +53,12 @@
 #define malloc SDL_malloc
 #define realloc SDL_realloc
 #define free SDL_free
+/* there is no 'dealloca' in stb_vorbis: we need alloca()
+#ifdef alloca
+#undef alloca
+#endif
 #define alloca(x) ((void *) SDL_stack_alloc(Uint8, (x)))
-#define dealloca(x) SDL_stack_free((x))
+*/
 #define ldexp(v, e) SDL_scalbn((v), (e))
 #define abs(x) SDL_abs(x)
 #define cos(x) SDL_cos(x)

diff --git a/src/stb_vorbis.h b/src/stb_vorbis.h
@@ -559,14 +559,6 @@ enum STBVorbisError
    #include <string.h>
    #include <assert.h>
    #include <math.h>
-
-   // find definition of alloca if it's not in stdlib.h:
-   #if defined(_MSC_VER) || defined(__MINGW32__)
-      #include <malloc.h>
-   #endif
-   #if defined(__linux__) || defined(__linux) || defined(__EMSCRIPTEN__)
-      #include <alloca.h>
-   #endif
 #else // STB_VORBIS_NO_CRT
    #ifndef NULL
    #define NULL 0
@@ -584,8 +576,19 @@ enum STBVorbisError
 
 #include <limits.h>
 
-#if defined(__MINGW32__) && !defined(alloca)
-   #define alloca __builtin_alloca
+/* we need alloca() regardless of STB_VORBIS_NO_CRT,
+ * because there is not a corresponding 'dealloca' */
+#if !defined(alloca)
+# if defined(HAVE_ALLOCA_H)
+#  include <alloca.h>
+# elif defined(__GNUC__)
+#  define alloca __builtin_alloca
+# elif defined(_MSC_VER)
+#  include <malloc.h>
+#  define alloca _alloca
+# elif defined(__WATCOMC__)
+#  include <malloc.h>
+# endif
 #endif
 
 #ifndef STB_FORCEINLINE