Some minor tweaks that will help down the line

Makefile

@@ -1,21 +1,22 @@
 objs = main.o
 
 CC = clang
+COMMON_FLAGS = -std=c11
 OUT_NAME = the_alloc
 
-dev: FLAGS= -g -D UNIT_TESTS
+dev: CFLAGS= $(COMMON_FLAGS) -g -D UNIT_TESTS
 dev: $(OUT_NAME)
 	valgrind ./$(OUT_NAME)
 
-release: FLAGS= -O2
+release: CFLAGS= $(COMMON_FLAGS) -O2
 release: clean $(OUT_NAME)
 	rm *.o
 
 $(OUT_NAME): $(objs)
-	$(CC) $(FLAGS) -o $(OUT_NAME) $(objs)
+	$(CC) $(CFLAGS) -o $(OUT_NAME) $(objs)
 
 clean:
 	rm -f *.o $(OUT_NAME)
 
 main.o: main.c
-	$(CC) $(FLAGS) -c main.c -o main.o
+	$(CC) $(CFLAGS) -c main.c -o main.o

allocator_internal.h

@@ -16,23 +16,23 @@ struct TopLevel {
 
 // All three of these types should be memory-compatible with each other
 
-struct TreeAlloc {
+typedef struct TreeAlloc {
   char type;  // Should be RT_TREE_NODE
   struct TreeAlloc *parent;
   struct TreeAlloc *left;
   struct TreeAlloc *right;
   size_t size;
-}
+} TreeAlloc
 
-struct FreeSpace {
+typedef struct FreeSpace {
   char type;  // Should be RT_FREESPACE
   struct FreeSpace *parent;
   struct FreeSpace *left;
   struct FreeSpace *right;
   size_t size;
-}
+} FreeSpace
 
-struct WatermarkAlloc {
+typedef struct WatermarkAlloc {
   char type;  // Should be RT_WATERMARK
   struct TreeAlloc *parent;
   struct TreeAlloc *left;
@@ -40,10 +40,10 @@ struct WatermarkAlloc {
   size_t size;
   int num_allocs;
   void *next_alloc;
-}
+} WatermarkAlloc
 
-struct TreeAlloc *insert_node_at(void *address, int padding, int align, int size);
-struct TreeAlloc *search_by_address(TreeAlloc *root, void *address);
-struct TreeAlloc *search_by_size(TreeAlloc *root, int padding, int align, int size);
+TreeAlloc *insert_node_at(void *address, int padding, int align, int size);
+TreeAlloc *search_by_address(TreeAlloc *root, void *address);
+TreeAlloc *search_by_size(TreeAlloc *root, int padding, int align, int size);
 
 #endif