`const` proc in `let` array causes invalid codegen

[Anuken]

Code

type ProcType = proc()
const something: ProcType = proc() = discard
let arr: array[1, ProcType] = [something]

Current Output

/home/anuke/.cache/nim/bug_d/@mbug.nim.c: In function ‘NimMainModule’:
/home/anuke/.cache/nim/bug_d/@mbug.nim.c:413:99: error: request for member ‘ClE_0’ in something not a structure or union
  413 | lzADdspe4KtMwjNjbL8g[0].ClE_0), colonanonymous___DxAxlW4RjxKP1O7MGX2PnQ.ClE_0);
      |                                                                        ^

/home/anuke/.cache/nim/bug_d/@mbug.nim.c:414:80: error: request for member ‘ClP_0’ in something not a structure or union
  414 | tMwjNjbL8g[0].ClP_0 = colonanonymous___DxAxlW4RjxKP1O7MGX2PnQ.ClP_0;
      |                                                              ^

Error: execution of an external compiler program 'gcc -c  -w -fmax-errors=3   -I'/home/anuke/.choosenim/toolchains/nim-#devel/lib' -I/home/anuke -o /home/anuke/.cache/nim/bug_d/@mbug.nim.c.o /home/anuke/.cache/nim/bug_d/@mbug.nim.c' failed with exit code: 1

Expected Output

successful compilation, or at least a nim compilation error

Workarounds

• Declaring both the proc and the array as const fixes the problem.

Additional Information

• Occurs in 1.4.2 as well as latest HEAD
• Occurs with and without --gc:arc

$ nim -v
Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2021-01-16
Copyright (c) 2006-2021 by Andreas Rumpf

44ceefa9fefca58ba32e9638f754d7f4ca8a2b82 (current git head)

[cooldome]

I believe this line should not compile:

const something: ProcType = proc() = discard

[bung87]

after debugging the problem is

something: ProcType
           ^^^^^^

the sym is checked passed as closure, the value is nimcall

[Araq]

Yes but you can pass a nimcall to a closure, there is an implicit conversion for this case.

[bung87]

Yes but you can pass a nimcall to a closure, there is an implicit conversion for this case.

I know that, but am not sure if it make sense "a const closure proc" , I discussed with @beef331 in discord, then I decide make it a CT error.