feat(allocator): implemented basic free function to free allocated memory

Include/Hallocy/Allocator.h

@@ -24,7 +24,11 @@
 #define HALLOCY_ALLOCATOR
 
 #include <stddef.h>
+#include <stdbool.h>
+
+#include "Error.h"
 
 void *hallocy_malloc(size_t size);
+HallocyError hallocy_free(void *pointer);
 
 #endif

Include/Hallocy/Error.h

@@ -0,0 +1,34 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * -----------------------------------------------------------------------------
+ * File: Error.h
+ * Description:
+ *  This file contains the ErrorCode enum that defines the error codes for the 
+ *  library.
+ * 
+ * Author: Mineplay
+ * -----------------------------------------------------------------------------
+ */
+#ifndef HALLOCY_ERROR
+#define HALLOCY_ERROR
+
+typedef enum {
+    HALLOCY_ERROR_NONE = 0,
+    HALLOCY_ERROR_INVALID_POINTER = 1,
+    HALLOCY_ERROR_OUT_OF_MEMORY = 2,
+    HALLOCY_ERROR_UNKNOWN = 3,
+    HALLOCY_ERROR_INVALID_PARAM = 4
+} HallocyError;
+
+#endif

Src/Hallocy/Allocator.c

@@ -27,6 +27,7 @@
 #elif defined(__linux__)
 #include <unistd.h>
 #include <sys/mman.h>
+#include <errno.h>
 #endif
 
 typedef struct HallocyMemoryHeader {
@@ -64,4 +65,53 @@ void *hallocy_malloc(size_t size) {
     memory_pointer->next = NULL;
 
     return (void*)(memory_pointer + 1);
+}
+
+HallocyError hallocy_free(void *pointer) {
+    if (pointer == NULL) {
+        return HALLOCY_ERROR_INVALID_POINTER;
+    }
+
+    HallocyMemoryHeader *memory_header = ((HallocyMemoryHeader*)pointer) - 1;
+    #if defined(_WIN32)
+    bool result = VirtualFree(memory_header, 0, MEM_RELEASE);
+    if (result == false) {
+        DWORD error = GetLastError();
+        switch (error) {
+            case ERROR_INVALID_PARAMETER:
+                return HALLOCY_ERROR_INVALID_PARAM;
+
+            case ERROR_NOT_ENOUGH_MEMORY:
+                return HALLOCY_ERROR_OUT_OF_MEMORY;
+
+            case ERROR_INVALID_HANDLE:
+                return HALLOCY_ERROR_INVALID_POINTER;
+
+            case ERROR_INVALID_ADDRESS:
+                return HALLOCY_ERROR_INVALID_POINTER;
+
+            default:
+                return HALLOCY_ERROR_UNKNOWN;
+        }
+    }
+    #elif defined(__linux__)
+    int result = munmap(memory_header, memory_header->size);
+    if (result == -1) {
+        switch (errno) {
+            case EINVAL:
+                return HALLOCY_ERROR_INVALID_PARAM;
+
+            case ENOMEM:
+                return HALLOCY_ERROR_OUT_OF_MEMORY;
+
+            case EFAULT:
+                return HALLOCY_ERROR_INVALID_POINTER;
+
+            default:
+                return HALLOCY_ERROR_UNKNOWN;
+        }
+    }
+    #endif
+
+    return HALLOCY_ERROR_NONE;
 }

Src/Main.c

@@ -3,10 +3,21 @@
 
 int main() {
     char *memory = (char *)hallocy_malloc(3);
+    if (memory == NULL) {
+        printf("Failed it allocate memory!");
+        return -1;
+    }
+
     memory[0] = 'H';
     memory[1] = 'i';
     memory[2] = '\0';
-    
+
     printf("%s\n", memory);
+    int code = hallocy_free(memory);
+    if (code != HALLOCY_ERROR_NONE) {
+        printf("Failed to free memory error code (%d)!", code);
+        return -1;
+    }
+
     return 0;
 }