wrong error msg when macro called with wrong number of args

[timotheecour]

reduced from a more complex example:

in case1, I would expect error message to be something like: bar expected 2 arguments (lambda: untyped, arg:typed) ; got 3

instead, currently the compiler tries to evaluate fun, which fails because it's not meant to be evaluated in this context.

in summary: we should evaluate number of arguments first before any other mismatch logic.
Is there anything blocking this logic? (eg: varargs[untyped] ?)

import macros

macro bar*(lambda: untyped, arg:typed):untyped=
  dumpTree(lambda)
  result = newStmtList()

block:
  template foo[T](fun: untyped, a:T, b:T): auto =
    when defined(case1):
      discard bar(fun, a, b)
    when defined(case2):
      discard bar(fun, a)
    0

  discard foo(u1 => u1, 2, 3)

rnim -d:case2 bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim
nim c --nimcache:/tmp/nim//nimcache/ -o:/tmp/nim//app -r -d:case2 bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim
Hint: used config file '/Users/timothee/git_clone/nim/Nim/config/nim.cfg' [Conf]
Hint: used config file '/Users/timothee/.config/nim/nim.cfg' [Conf]
Hint: used config file '/Users/timothee/git_clone/nim/timn/nim.cfg' [Conf]
Ident "lambda"
/Users/timothee/git_clone/nim/timn/bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim(7, 1) template/generic instantiation from here
/Users/timothee/git_clone/nim/timn/bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim(15, 14) template/generic instantiation from here
/Users/timothee/git_clone/nim/timn/bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim(12, 18) Error: expression '' has no type (or is ambiguous)
        discard bar(fun, a)
                   ^

rnim -d:case1 bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim
nim c --nimcache:/tmp/nim//nimcache/ -o:/tmp/nim//app -r -d:case1 bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim
Hint: used config file '/Users/timothee/git_clone/nim/Nim/config/nim.cfg' [Conf]
Hint: used config file '/Users/timothee/.config/nim/nim.cfg' [Conf]
Hint: used config file '/Users/timothee/git_clone/nim/timn/nim.cfg' [Conf]
Ident "lambda"
/Users/timothee/git_clone/nim/timn/bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim(7, 1) template/generic instantiation from here
/Users/timothee/git_clone/nim/timn/bugs/compiler/t23_errmsg_confusing_with_macro_num_arg_mismatch.nim(15, 18) Error: undeclared identifier: '=>'
    discard foo(u1 => u1, 2, 3)
                   ^

[Araq]

in summary: we should evaluate number of arguments first before any other mismatch logic.

Why? Which section of the spec covers that "should"?

[jangko]

simpler working example:

type
  Fruit = enum
    apple
    banana
    orange
    
macro hello(x, y: untyped) =
  echo "OK"
  
hello(apple, banana, orange)

got a less confusing error message:

abc.nim(12, 6) Error: type mismatch: got <Fruit, Fruit, Fruit>
but expected one of:
macro hello(x, y: untyped)

expression: hello(apple, banana, orange)

this one produces a really confusing error message(using undeclared identifier)

macro hello(x, y: untyped) =
  echo "OK"
  
hello(apple, banana, orange)

apc.nim(12, 7) Error: undeclared identifier: 'apple'

expect something like:

abc.nim(12, 6) Error: type mismatch: got <void, void, void> # `void` can be replaced with something else
but expected one of:
macro hello(x, y: untyped)

expression: hello(apple, banana, orange)

or a more meaningful error message like @timotheecour wants