macro generated objects with field name containing '`' cannot be accessed

[alaviss]

Example

import macros

macro emit(): untyped =
  result = newStmtList()

  let field = ident("x`")
  let obj = nnkObjectTy.newTree(newEmptyNode(), newEmptyNode()):
    nnkRecList.newTree:
      newIdentDefs(field, ident"int")

  let env = ident"env"
  result.add:
    nnkTypeSection.newTree:
      nnkTypeDef.newTree(env, newEmptyNode(), obj)

  result.add(
    newLetStmt(ident"e", newCall(env)),
    nnkDiscardStmt.newTree(nnkDotExpr.newTree(ident"e", field))
  )

emit()

Actual Output

test.nim(6, 20) Error: undeclared field: 'x`' for type test.env [type declared in test.nim(11, 18)]

Expected Output

This should compile normally

Additional Information

• This breaks CPS when dealing with AST originating from a template, as they contains `gensym in their repr.
• It seems that the ` character is key to triggering this bug. Other special characters does not seem to cause any problems.
• Bisect found fix(sem): issues with method-call syntax in templates #1298 to be the culprit.

Generated code:

type
  env = object
    x`: int

let e = env()
discard e.x`

AST form:

StmtList
  TypeSection
    TypeDef
      Ident "env"
      Empty
      ObjectTy
        Empty
        Empty
        RecList
          IdentDefs
            Ident "x`"
            Ident "int"
            Empty
  LetSection
    IdentDefs
      Ident "e"
      Empty
      Call
        Ident "env"
  DiscardStmt
    DotExpr
      Ident "e"
      Ident "x`"

[zerbina]

Fixed by #1389.