[ox/std] Add alloca and malloca

deps/ox/src/ox/std/new.hpp

@@ -5,8 +5,42 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
+
 #pragma once
 
 #include "types.hpp"
 
+#if defined(_MSC_VER)
+#include <malloc.h>
+#define ox_alloca(size) _alloca(size)
+#elif !defined(OX_USE_STDLIB)
+#define ox_alloca(size) __builtin_alloca(size)
+#else
+#include <cstdlib>
+#include <alloca.h>
+#define ox_alloca(size) alloca(size)
+#endif
+
+
+namespace ox {
+
+constexpr auto MaxAllocaSize = 10 * 1024;
+
+}
+
+#if defined(OX_USE_STDLIB)
+#define ox_malloca(size) size > MaxAllocaSize ? malloc(MaxAllocaSize) : ox_alloca(size)
+#else
+#define ox_malloca(size) ox_alloca(size)
+#endif
+
+inline void ox_freea(std::size_t size, void *ptr) {
+	if constexpr(ox::defines::UseStdLib) {
+		if (size > ox::MaxAllocaSize) {
+			free(ptr);
+		}
+	}
+}
+
+
 void* operator new(std::size_t, void*) noexcept;