Update vm.c

Author: AzliRynz

vm.c

@@ -1,6 +1,12 @@
+#include "vm.h"
 #include "bloat.h"
+#include "chunk.h"
 #include "value.h"
-#include "vm.h"
+#include "object.h"
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
 
 static InterpretResult run(VM* vm) {
     #define READ_BYTE() (*vm->ip++)
@@ -115,18 +121,88 @@ bool values_equal(Value a, Value b) {
     switch (a.type) {
         case VAL_NIL: return true;
         case VAL_BOOL: return AS_BOOL(a) == AS_BOOL(b);
-        case VAL_INT: return AS_INT(a) == AS_INT(b);
-        case VAL_FLOAT: return AS_FLOAT(a) == AS_FLOAT(b);
-        case VAL_STRING: return strcmp(AS_STRING(a), AS_STRING(b)) == 0;
+        case VAL_NUMBER: return AS_NUMBER(a) == AS_NUMBER(b);
         case VAL_OBJ: return AS_OBJ(a) == AS_OBJ(b);
         default: return false;
     }
 }
 
 Value peek(int offset) {
     VM* vm;
-    if ((intptr_t) (vm->stack_top - offset - 1) < 0) {
-        printf("Stack underflow!");
+    if ((intptr_t)(vm->stack_top - offset - 1) < 0) {
+        runtime_error("Stack underflow!");
+        return NIL_VAL;
+    }
+    return vm->stack[(int)(vm->stack_top - offset - 1)];
+}
+
+void* reallocate(void* pointer, size_t oldSize, size_t newSize) {
+    vm->bytes_allocated += newSize - oldSize;
+    
+    if (newSize > oldSize) {
+        if (vm->bytes_allocated > vm->next_gc) {
+            collect_garbage(vm);
+        }
+    }
+
+    if (newSize == 0) {
+        free(pointer);
+        return NULL;
+    }
+
+    void* result = realloc(pointer, newSize);
+    if (result == NULL) exit(1);
+    return result;
+}
+
+void collect_garbage(VM* vm) {
+    for (Value* slot = vm->stack; slot < vm->stack_top; slot++) {
+        mark_value(vm, *slot);
+    }
+
+    Object** object = &vm->objects;
+    while (*object != NULL) {
+        if (!(*object)->is_marked) {
+            Object* unreached = *object;
+            *object = unreached->next;
+            free_object(unreached);
+        } else {
+            (*object)->is_marked = false;
+            object = &(*object)->next;
+        }
+    }
+
+    vm->next_gc = vm->bytes_allocated * 2;
+}
+
+void mark_object(VM* vm, Object* object) {
+    if (object == NULL) return;
+    if (object->is_marked) return;
+    
+    object->is_marked = true;
+    // If the object contains references to other objects,
+    // they should be marked here
+}
+
+void mark_value(VM* vm, Value value) {
+    if (IS_OBJ(value)) {
+        mark_object(vm, AS_OBJ(value));
+    }
+}
+
+void runtime_error(const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    vfprintf(stderr, format, args);
+    va_end(args);
+    fputs("\n", stderr);
+}
+
+void free_objects(VM* vm) {
+    Object* object = vm->objects;
+    while (object != NULL) {
+        Object* next = object->next;
+        free_object(object);
+        object = next;
     }
-    return vm->stack[(int) (vm->stack_top - offset - 1)];
 }