Nim 2.0.2 regression: macros.getType(…).kind of object type is nnkBracketExpr (was nnkObjectTy in Nim 2.0.0)

[flyx]

Description

getType from macros returns an nnkBracketExpr for an object type with Nim 2.0.2 where Nim 2.0.0 returned an nnkObjectTy:

import macros

type
  Container = object
    foo: string

proc canBeImplicit(t: typedesc): string {.compileTime.} =
  ## returns empty string if type can be implicit, else the reason why it can't
  let tDesc = getType(t)
  if tDesc.kind != nnkObjectTy: return "type is not an object, but a " & $tDesc.kind
  return ""

const res = canBeImplicit(Container)
assert len(res) == 0, "unexpected error for canBeImplicit: " & res

Nim Version

Nim 2.0.2 on macOS, Linux and Window, see CI run of the test above

Current Output

/home/runner/work/NimYAML/NimYAML/test/tnimregress.nim(14) tnimregress
/home/runner/.choosenim/toolchains/nim-2.0.2/lib/std/assertions.nim(41) failedAssertImpl
/home/runner/.choosenim/toolchains/nim-2.0.2/lib/std/assertions.nim(36) raiseAssert
/home/runner/.choosenim/toolchains/nim-2.0.2/lib/system/fatal.nim(53) sysFatal
Error: unhandled exception: /home/runner/work/NimYAML/NimYAML/test/tnimregress.nim(14, 1) `len(res) == 0` unexpected error for canBeImplicit: type is not an object, but a nnkBracketExpr [AssertionDefect]
Error: execution of an external program failed: '/home/runner/work/NimYAML/NimYAML/test/tnimregress'
Error: Process completed with exit code 1.

Expected Output

(nothing)

Possible Solution

No response

Additional Information

This breaks NimYAML, specifically its implicit pragma. NimYAML callers that do not use this feature are not affected.

[flyx]

Let's try this bisecting feature.

!nim c

import macros

type
  Container = object
    foo: string

proc canBeImplicit(t: typedesc): string {.compileTime.} =
  ## returns empty string if type can be implicit, else the reason why it can't
  let tDesc = getType(t)
  if tDesc.kind != nnkObjectTy: return "type is not an object, but a " & $tDesc.kind
  return ""

const res = canBeImplicit(Container)
assert len(res) == 0, "unexpected error for canBeImplicit: " & res

[ringabout]

!nim c

import macros

type
  Container = object
    foo: string

proc canBeImplicit(t: typedesc): string {.compileTime.} =
  ## returns empty string if type can be implicit, else the reason why it can't
  let tDesc = getType(t)
  if tDesc.kind != nnkObjectTy: return "type is not an object, but a " & $tDesc.kind
  return ""

const res = canBeImplicit(Container)
assert len(res) == 0, "unexpected error for canBeImplicit: " & res

[metagn]

import macros

type
  Container = object
    foo: string

proc canBeImplicit(t: typedesc): string {.compileTime.} =
  let tDesc = getType(t)
  echo tDesc.treeRepr

const res = canBeImplicit(Container)

BracketExpr
  Sym "typeDesc"
  Sym "Container"

An easy workaround is:

var tDesc = getType(t)
while tDesc.kind == nnkBracketExpr and tDesc[0].eqIdent"typeDesc":
  tDesc = getType(tDesc[1])

Caused by #22581, hence this test change.