ps6: task 2

ps6/src/generator.c

@@ -483,11 +483,41 @@ static void generate_if_statement(node_t* statement)
   LABEL("%s", endif_label);
 }
 
+int while_counter = 0;
+int root_while = 0, nesting_level = 0;
+
 static void generate_while_statement(node_t* statement)
 {
   // TODO (Task 2):
   // Implement while loops, similarily to the way if statements were generated.
   // Remember to make label names unique, and to handle nested while loops.
+
+  char while_label[8];
+  snprintf(while_label, 8, "WHILE%d", while_counter);
+  char endwhile_label[8];
+  snprintf(endwhile_label, 8, "ENDWH%d", while_counter);
+
+  if (nesting_level == 0)
+    root_while = while_counter;
+  while_counter++;
+  nesting_level++;
+
+  LABEL("%s", while_label);
+
+  node_t *condition = statement->children[0];
+  generate_expression(condition);
+
+  CMPQ("$0", RAX);
+  JE(endwhile_label);
+
+  node_t *body = statement->children[1];
+  generate_statement(body);
+
+  JMP(while_label);
+
+  LABEL("%s", endwhile_label);
+
+  nesting_level--;
 }
 
 // Leaves the currently innermost while loop using its end-label