Improve error message when trying to call non-@tool function from @tool script

[Calinou]

• This closes Improve error message for calling non-tool scripts from tool scripts #36592.

Testing project: test_tool_script_function_error.zip

Preview

Before

  res://Node2D.gd:6 - Invalid call. Nonexistent function 'say_hello' in base 'Node (ChildNode.gd)'.

After

 res://Node2D.gd:6 - Invalid call. Nonexistent function 'say_hello' in base 'Node (ChildNode.gd)' ('say_hello' is from a non-@tool script, but is called from @tool script; make the script containing 'say_hello' @tool).

[npip99]

The comments in the code say "is likely", but the actual message to the user speaks as a matter of fact.

Is it guaranteed to be that case? The comment shouldn't say "is likely" then. Is it not guaranteed to be that case? The user to the message should say "it may be" or maybe the message should just be "$STANDARD_MESSAGE (function is not in @tool script?)", mimic'ing question-mark "?" bugs for other compilers that theorize what the issue is to the user ("Missing semi-colon?").

[AThousandShips]

I think this is too broad, maybe:

Suggested change

	if (base->has_method(methodstr)) {
	if (err.error == Callable::CallError::CALL_ERROR_INVALID_METHOD && base->has_method(methodstr)) {

Same below

This part can be reached with other errors, not just not found, like invalid arguments, see for example this output from CI:

Invalid type in function 'expect_typed' in base 'RefCounted (typed_array_pass_basic_to_typed.gd)' ('expect_typed' is from a non-@tool script, but is called from @tool script; make the script containing 'expect_typed' @tool). The array of argument 1 (Array) does not have the same element type as the expected typed array argument.

Also same about the methodstr:

methodstr = String(*argptrs[0]) + " (via TreeItem.call_recursive)";

methodstr = base->operator String() + " (Callable)";

methodstr = String(*argptrs[0]) + " (via call)";

So some more sensitive checking needs to be done IMO

[AThousandShips]

This won't work if it's via call, see above:

methodstr = String(*argptrs[0]) + " (via call)";

[dalexeev]

• See also GDScript: Fix message when calling non-tool function in tool mode #94511.

[dalexeev]

#36592 was fixed by #94511. Thanks for the contribution nonetheless!