Invalid C code generated when creating an Option out of deref'd value, which contains a reference to its own type, gotten from an Option which is None at compile time.

[kayabaNerve]

As the title says, a very specific case involving Options causes Nim to generate invalid C.

Example

import options

type Nested = ref object
  child: Option[Nested]

let x = none(Nested)
discard some(Nested()[])

Current Output

~/.cache/nim/test_codegen_d/stdlib_options.nim.c: In function ‘some__9ahAc9c9c9bfjwxun9c9c2ibgAFg’:
~/.cache/nim/test_codegen_d/stdlib_options.nim.c:324:21: error: ‘tyObject_Option__LdGjTDNxAxkpdsbs9c9aMtGQ {aka struct tyObject_Option__LdGjTDNxAxkpdsbs9c9aMtGQ}’ has no member named ‘has’
  (*Result).val.child.has = val.child.has;
                     ^
~/.cache/nim/test_codegen_d/stdlib_options.nim.c:324:37: error: ‘tyObject_Option__LdGjTDNxAxkpdsbs9c9aMtGQ {aka struct tyObject_Option__LdGjTDNxAxkpdsbs9c9aMtGQ}’ has no member named ‘has’
  (*Result).val.child.has = val.child.has;
                                     ^
Error: execution of an external compiler program 'gcc -c  -w -pthread   -I'~/.choosenim/toolchains/nim-#devel/lib' -o ~/.cache/nim/test_codegen_d/stdlib_options.nim.c.o ~/.cache/nim/test_codegen_d/stdlib_options.nim.c' failed with exit code: 1

Expected Output

A runtime error that you can't get a value from None.

Additional Information

• Inlining any of this causes valid code to be generated.
• Using a non-circular type also causes valid code to be generated.
• Using some instead of none also causes valid code to be generated.

Tested on 1.2.0 and the latest devel.

[kayabaNerve]

Initially uploaded the wrong code; fixed.

[ghost]

Still an issue

[shirleyquirk]

related to #12695
when reducing that bug, which also involves a nested type:

type
  Foo[T] = object
    when T is ptr:
      value:T
    else:
      notvalue:T
proc access[A](self:A) = discard
proc store[T](self: var Foo[ptr T]) = access(self.value)

type
  MyType = ptr object
    next: Foo[MyType]

var f:Foo[MyType]

f.store()

i get

CC: bug1.nim
/home/bwsq/.cache/nim/bug1_d/@mbug1.nim.c: In function ‘store__bug49_29’:
/home/bwsq/.cache/nim/bug1_d/@mbug1.nim.c:82:34: error: ‘tyObject_Foo__D9a9
crXqyX59c9a5NYkXwC5XKw’ has no member named ‘value’; did you mean ‘notvalue
’?
   82 |         access__bug49_35((*self).value);
      |                                  ^~~~~
      |                                  notvalue