Added ralloc function.

.idea/vcs.xml

@@ -1,5 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GitSharedSettings">
+    <option name="FORCE_PUSH_PROHIBITED_PATTERNS">
+      <list />
+    </option>
+  </component>
   <component name="VcsDirectoryMappings">
     <mapping directory="" vcs="Git" />
   </component>

main.c

@@ -23,27 +23,26 @@ struct block* last = NULL;
 /// @returns The new memory block.
 struct block* extend_heap(size_t s)
 {
-    struct block* b = sbrk(0);
+	// Ensure the allocated size is at least the minimum block size
+	if (s < MINIMUM_BLOCK_SIZE)
+		s = MINIMUM_BLOCK_SIZE;
 
-    // Ensure the allocated size is at least the minimum block size
-    if (s < MINIMUM_BLOCK_SIZE) {
-        s = MINIMUM_BLOCK_SIZE;
-    }
+	struct block* b = sbrk(0);
 
-    if (sbrk(BLOCK_SIZE + s) == (void*)-1)
-        return NULL;
+	if (sbrk(BLOCK_SIZE + s) == (void*)-1)
+		return NULL;
 
-    b->size = s;
-    b->prev = last;
-    b->next = NULL;
-    b->free =  0;
+	b->size = s;
+	b->prev = last;
+	b->next = NULL;
+	b->free = 0;
 
-    if (last)
-        last->next = b;
+	if (last)
+		last->next = b;
 
-    last = b;
+	last = b;
 
-    return b;
+	return b;
 }
 
 /// Finds the first block that will fit the given size.
@@ -58,6 +57,10 @@ struct block* find_first(size_t s)
 	return current;
 }
 
+/// Fragments an existing free memory block into the given size.
+/// @param [in] in The memory block to fragment.
+/// @param [in] s The size of the new memory block.
+/// @returns The new memory block.
 struct block* fragment_block(struct block* in, size_t s)
 {
 	size_t totalSize = BLOCK_SIZE + s;
@@ -79,35 +82,49 @@ struct block* fragment_block(struct block* in, size_t s)
 /// @todo Fragmenting functionality.
 void* malloc(size_t size)
 {
-    struct block* b;
+	struct block* b;
 
-    size_t alignedSize = ALIGN4(size);
+	size = ALIGN4(size);
 
-    // Enforce the minimum block size
-    if (alignedSize < MINIMUM_BLOCK_SIZE) {
-        alignedSize = MINIMUM_BLOCK_SIZE;
-    }
+	if (first)
+	{
+		b = find_first(size);
+		if (!b)
+			b = extend_heap(size);
+		else if (b->size > BLOCK_SIZE + size)
+			b = fragment_block(b, size);
+	}
+	else
+	{
+		b = extend_heap(size);
+		if (!b)
+			return NULL;
 
-    if (first)
-    {
-        b = find_first(alignedSize);
-        if (!b)
-            b = extend_heap(alignedSize);
-        else if (b->size > BLOCK_SIZE + alignedSize)
-            b = fragment_block(b, alignedSize);
-    }
-    else
-    {
-        b = extend_heap(alignedSize);
-        if (!b)
-            return NULL;
+		first = b;
+	}
 
-        first = b;
-    }
-
-    return b +  1;
+	return b + 1;
 }
 
+void* realloc(void* ptr, size_t new_size)
+{
+	if (!ptr)
+		return malloc(new_size);
+
+	if (!new_size)
+		return NULL;
+
+	struct block* b = (struct block*)ptr - 1;
+	if (b->free)
+		return NULL;
+
+	if (b->size == new_size)
+		return ptr;
+	else if (b->size > BLOCK_SIZE + new_size)
+		return fragment_block(b, new_size) + 1;
+
+	return NULL;
+}
 
 /// Will flag the provided memory as free and will defragment other blocks adjacent to it.
 /// @param [in] ptr The memory to flag as free.