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 #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.