Options codegen error: ‘tyObject_Option__xxxx’ has no member named ‘has’

konradmb commented 1 year ago

Description

Minimal reproduction:

import options

type
  Node[T] = ref object
    value: T
    previous: Option[Node[T]]
    next: Option[Node[T]]
  LinkedList*[T] = object ## A doubly linked list.
    first: Option[Node[T]]
    last: Option[Node[T]]

var list = LinkedList[int]()
# let qwerqwer = list.first.get.next 
# This ^ line errors on stable (1.6.12), but not on current devel 1.9.1 (f7e3af0c2d68035a649cf9449cc4e02a7ea59e84)
let newNode = Node[int](value: 0,
                      next: list.first.get.next,
                      previous: Node[int].none).some

Nim Version

git hash: f7e3af0c2d68035a649cf9449cc4e02a7ea59e84 active boot switches: -d:release

Current Output

nim r -f -r "/home/konrad/.config/VSCodium/User/globalStorage/buenon.scratchpads/scratchpads/56b8016bc5c16deae167b5cfb0a76e9f/scratch8.nim"
Hint: used config file '/home/konrad/.choosenim/toolchains/nim-#devel/config/nim.cfg' [Conf]
Hint: used config file '/home/konrad/.choosenim/toolchains/nim-#devel/config/config.nims' [Conf]
..........................................................................
/home/konrad/.config/VSCodium/User/globalStorage/buenon.scratchpads/scratchpads/56b8016bc5c16deae167b5cfb0a76e9f/scratch8.nim(14, 5) Hint: 'newNode' is declared but not used [XDeclaredButNotUsed]
CC: ../../../../../../../.choosenim/toolchains/nim-#devel/lib/system/exceptions.nim
CC: ../../../../../../../.choosenim/toolchains/nim-#devel/lib/std/private/digitsutils.nim
CC: ../../../../../../../.choosenim/toolchains/nim-#devel/lib/std/assertions.nim
CC: ../../../../../../../.choosenim/toolchains/nim-#devel/lib/system/dollars.nim
CC: ../../../../../../../.choosenim/toolchains/nim-#devel/lib/system.nim
CC: ../../../../../../../.choosenim/toolchains/nim-#devel/lib/pure/options.nim
CC: scratch8.nim
/home/konrad/.cache/nim/scratch8_d/@mscratch8.nim.c: In function ‘NimMainModule’:
/home/konrad/.cache/nim/scratch8_d/@mscratch8.nim.c:574:20: error: ‘tyObject_Option__iPwdvoo5DamSoOdiAagILA’ has no member named ‘has’
  574 |         (*T1_).next.has = colontmpD_.has;
      |                    ^
/home/konrad/.cache/nim/scratch8_d/@mscratch8.nim.c:574:37: error: ‘tyObject_Option__iPwdvoo5DamSoOdiAagILA’ has no member named ‘has’
  574 |         (*T1_).next.has = colontmpD_.has;
      |                                     ^
Error: execution of an external compiler program 'gcc -c  -w -fmax-errors=3 -pthread   -I'/home/konrad/.choosenim/toolchains/nim-#devel/lib' -I/home/konrad/.config/VSCodium/User/globalStorage/buenon.scratchpads/scratchpads/56b8016bc5c16deae167b5cfb0a76e9f -o /home/konrad/.cache/nim/scratch8_d/@mscratch8.nim.c.o /home/konrad/.cache/nim/scratch8_d/@mscratch8.nim.c' failed with exit code: 1

Expected Output

No error

Possible Solution

Elegantbeef from Matrix says it is a "cgen bug For some reason it's calling .has for a Option[ref] even though it shouldnt"

Additional Information

This is a part of Exercism "Linked list" exercise, but I'm trying to solve it with options instead of nils.
There's also something wrong going on when I change the Node[T] = ref object to just Node[T] = object: compiler exits on "......" dots phase without any errors and leaves terminal without newline.

ghost commented 1 year ago

Might be a duplicate of https://github.com/nim-lang/Nim/issues/16754

konradmb commented 1 year ago

@Yardanico I can reproduce this one on --gc:none, --gc:arc, --gc:orc, --gc:refc. Although error messages are slightly different, it still generally boils down to "...has no member named ‘has’" Also, compiler probably crashes with normal object (not ref).

metagn commented 1 year ago

This:

import options

type
  NodeObj[T] = object
    value: T
    previous: Option[ref NodeObj[T]]
    next: Option[ref NodeObj[T]]
  Node[T] = ref NodeObj[T]
  LinkedList*[T] = object ## A doubly linked list.
    first: Option[Node[T]]
    last: Option[Node[T]]

var list = LinkedList[int]()
let newNode = Node[int](value: 0,
                      next: list.first.get.next,
                      previous: Node[int].none).some

gives:

prog.nim(17Error: unhandled exception: Can't obtain a value from a `none` [UnpackDefect]

While a similar workaround works for #16754

Edit: Actually this is probably the expected behavior of this code, so this workaround seems to work here as well

nim-lang / Nim