rust-lang / rust-lang/rust

Incorrect diagnostic "pattern requires `..` due to inaccessible fields" when matching in a macro

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#130,588 1 comment 0 reactions 1 assignee View on GitHub

@fmease is already working on this.

Since Sep 19, 2024.

A-diagnostics A-hygiene A-macros D-confusing T-compiler
Dominant language
Rust
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Description

Code
struct A {
    field1: String,
    field2: String,
}

fn test(x: A) {
    macro_rules! weird {
        () => { let A { field1 } = x; }
    }
    weird!();
}
Current output
error: pattern requires `..` due to inaccessible fields
  --> a.rs:8:21
   |
8  |         () => { let A { field1 } = x; }
   |                     ^^^^^^^^^^^^
9  |     }
10 |     weird!();
   |     -------- in this macro invocation
   |
   = note: this error originates in the macro `weird` (in Nightly builds, run with -Z macro-backtrace for more info)
help: ignore the inaccessible and unused fields
   |
8  |         () => { let A { field1, .. } = x; }
   |                               ++++
Desired output
error[E0027]: pattern does not mention field `field2`
 --> a.rs:8:21
  |
8 |         () => { let A { field1 } = x; }
  |                     ^^^^^^^^^^^^ missing field `field2`
  |
Rationale and extra context

It seems this error message gets generated whenever an incomplete pattern shows up within a macro invocation, whether or not the fields are actually inaccessible.

Other cases

No response

Rust Version

rustc 1.83.0-nightly (f79a912d9 2024-09-18)
binary: rustc
commit-hash: f79a912d9edc3ad4db910c0e93672ed5c65133fa
commit-date: 2024-09-18
host: x86_64-unknown-linux-gnu
release: 1.83.0-nightly
LLVM version: 19.1.0

Anything else?

No response

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