(defmodule Debug

  (defdynamic sanitize-addresses []
    (add-cflag "-fsanitize=address"))

  (register memory-balance (Fn [] Long))
  (register reset-memory-balance! (Fn [] ()))
  (register log-memory-balance! (Fn [Bool] ()))

  ;; The calls inside the form will be logged to stdout. Requires compiling with --log-memory.
  (defmacro memory-logged [form]
    (list 'do
          '(Debug.log-memory-balance! true)
          form
          '(Debug.log-memory-balance! false)))

  ;; Raises an error if the memory balance (nr of alloc:s minus nr of free:s) isn't 0. Requires compiling with --log-memory.
  (defmacro assert-balanced [form]
    (list 'let '[balance (Debug.memory-balance)]
          (list 'do
                (list 'let []
                      form)
                '(if (= balance (Debug.memory-balance))
                   ()
                   (do (IO.println &(fmt "Invalid memory balance: %d" (Debug.memory-balance)))
                       (System.exit 1)))
                ())))

  ;; Print the value of an expression to stdout, then return its value.
  (defn trace [x]
    (do
      (IO.println &(str &x))
      x))

  )

;; Crash the program with an error message unless the expression evaluates to 'true'.
(defmacro assert [expr]
  (list 'if (list '= true expr)
        ()
        (list 'do
              (list 'IO.println (list 'ref
                                      (list 'String.append (list 'String.copy "Assertion failed ")
                                            (list 'String.copy (source-location)))))
              '(System.exit 1))))