untyped argument used inside generic body gives undeclared identifier due to generic symbol resolution prepass

[martincohen]

I've encountered a strange problem with template and untyped argument. I'm not sure what exactly is going on. It feels like compiler bug really, as the two examples bellow are only different on wheteher I pass batch: var BatchArg to the function. Once I do, the template's untyped argument is being checked and results in undeclared identifier.

Any hints appreciated.

type Quad* = object
    a*: int

type Batch* = object
    a*: int

type BatchArg = Batch or ref Batch

# Works
proc testB*() =
    var quad = Quad()
    template attrib(member: untyped) =
        echo quad.member
    
    attrib(a)

testB()

# Doesn't work
proc testA*(batch: var BatchArg) =
    var quad = Quad()
    template attrib(member: untyped) =
        echo quad.member
    
    attrib(a) # << Error: undeclared identifier: 'a'

var batch = Batch()
testA(batch)

[timotheecour]

reduced:

  proc fun[T]() =
    template bar(member: untyped) = discard # works if that template is declared outside fun
    bar(a) # << Error: undeclared identifier: 'a'

it's caused by generic symbol resolution prepass (aka early symbol resolution) IIUC
=> refs: #8677

we need to check whether this bug is a dup