Syntax context output in --pretty expanded,hygiene doesn't represent linked syntax contexts

[huonw]

E.g.

#![feature(macro_rules)]
// minimal junk
#![no_std]

macro_rules! foo {
    ($x: ident) => { y + $x }
}

fn bar() {
    let x = 1;
    foo!(x)
}

becomes

#![feature(macro_rules)]
// minimal junk
#![no_std]


fn bar /* 61#0 */() { let x /* 58#2 */ = 1; y /* 60#4 */ + x /* 58#5 */ }

Specifically, the syntax contexts of x /* 58#2 */ and x /* 58#5 */ are linked (the xs refer to the same identifier, even with hygiene) but this is not represented in the output at all, so one might interpret them as being distinct identifiers.

[steveklabnik]

There is no more pretty=hygene, was it replaced with something?

[Mark-Simulacrum]

Closing. pretty=hygiene is apparently no longer a thing, and the output looks sufficiently different with pretty=expanded,identified that I don't think it's the same.

[Eh2406]

There is a FIXME related to this issue,
https://github.com/rust-lang/rust/blob/master/src/librustc_driver/pretty.rs#L459
Now that the issue is closed can the FIXME be fix, or made more specific?

[Mark-Simulacrum]

Looks like pretty=expanded,hygiene is a thing though so reopening... output today is below. I'm not completely sure whether this is fixed or not --- the output looks the same for the two xs, I guess? Not sure which are being referred to either...

error[E0425]: cannot find value `y` in this scope
  --> test.rs:5:22
   |
5  |     ($x: ident) => { y + $x }
   |                      ^ did you mean `x`?
...
10 |     foo!(x)
   |     ------- in this macro invocation

#![feature(prelude_import)]
#![no_std]
// minimal junk
#![no_std]
#[prelude_import]
use core /* 94#0 */::prelude /* 98#0 */::v1 /* 99#0 */::*;
#[macro_use]
extern crate core /* 94 */ as core /* 94#0 */;

macro_rules! foo /* 87#0 */(( $ x : ident ) => { y + $ x });

fn bar /* 91#0 */() { let x /* 88#0 */ = 1; y /* 90#2 */ + x /* 88#0 */ }
error: aborting due to previous error