Complete memory allocation and deallocation function definitions

src/mem/util/mem_utils.c

@@ -1,8 +1,43 @@
 #include "mem_utils.h"
 #include "aliases.h"
+#include "platform.h"
 #include <assert.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <string.h>
+
+#if defined(WAPP_PLATFORM_WINDOWS)
+#include <Windows.h>
+#include <memoryapi.h>
+
+internal const i32 access_types[] = {
+    [WAPP_MEM_ACCESS_NONE] = PAGE_NOACCESS,
+    [WAPP_MEM_ACCESS_READ_ONLY] = PAGE_READONLY,
+    [WAPP_MEM_ACCESS_EXEC_ONLY] = PAGE_EXECUTE,
+    [WAPP_MEM_ACCESS_READ_WRITE] = PAGE_READWRITE,
+    [WAPP_MEM_ACCESS_READ_EXEC] = PAGE_EXECUTE_READ,
+    [WAPP_MEM_ACCESS_READ_WRITE_EXEC] = PAGE_EXECUTE_READWRITE,
+};
+
+internal inline void *alloc_windows(u64 size, MemAccess access,
+                                    MemAllocFlags flags);
+#elif defined(WAPP_PLATFORM_POSIX)
+#include <sys/mman.h>
+
+internal const i32 access_types[] = {
+    [WAPP_MEM_ACCESS_NONE] = PROT_NONE,
+    [WAPP_MEM_ACCESS_READ_ONLY] = PROT_READ,
+    [WAPP_MEM_ACCESS_EXEC_ONLY] = PROT_EXEC,
+    [WAPP_MEM_ACCESS_READ_WRITE] = PROT_READ | PROT_WRITE,
+    [WAPP_MEM_ACCESS_READ_EXEC] = PROT_READ | PROT_EXEC,
+    [WAPP_MEM_ACCESS_READ_WRITE_EXEC] = PROT_READ | PROT_WRITE | PROT_EXEC,
+};
+
+internal inline void *alloc_posix(u64 size, MemAccess access,
+                                  MemAllocFlags flags);
+#else
+#error "Unrecognised platform"
+#endif
 
 internal bool is_power_of_two(u64 num) { return (num & (num - 1)) == 0; }
 
@@ -26,3 +61,48 @@ void *wapp_mem_util_align_forward(void *ptr, u64 alignment) {
 
   return (void *)p;
 }
+
+void *wapp_mem_util_alloc(u64 size, MemAccess access, MemAllocFlags flags,
+                          MemInitType type) {
+#if defined(WAPP_PLATFORM_WINDOWS)
+  void *output = alloc_windows(size, access, flags);
+#elif defined(WAPP_PLATFORM_POSIX)
+  void *output = alloc_posix(size, access, flags);
+#else
+  return NULL;
+#endif
+
+  if (type == WAPP_MEM_INIT_INITIALISED) {
+    memset(output, 0, size);
+  }
+
+  return output;
+}
+
+void wapp_mem_util_free(void *ptr, u64 size) {
+#if defined(WAPP_PLATFORM_WINDOWS)
+  VirtualFree(ptr, size, MEM_RELEASE);
+#elif defined(WAPP_PLATFORM_POSIX)
+  munmap(ptr, size);
+#endif
+}
+
+#ifdef WAPP_PLATFORM_WINDOWS
+internal inline void *alloc_windows(u64 size, MemAccess access,
+                                    MemAllocFlags flags) {
+  return VirtualAlloc2(NULL, NULL, (SIZE_T)size, flags, access_types[access]);
+}
+#endif
+
+#if defined(WAPP_PLATFORM_POSIX)
+internal inline void *alloc_posix(u64 size, MemAccess access,
+                                  MemAllocFlags flags) {
+  i32 alloc_flags = flags | MAP_ANON | MAP_PRIVATE;
+
+#ifdef WAPP_PLATFORM_LINUX
+  alloc_flags |= MAP_NORESERVE;
+#endif
+
+  return mmap(NULL, size, access_types[access], alloc_flags, -1, 0);
+}
+#endif