Fix a format_args span to be expansion

[camsteffen]

I found this while exploring solutions for rust-lang/rust-clippy#7843.

r? @m-ou-se

[camsteffen]

Hmm the change to diagnostics is probably not acceptable.

It would be nice to detect the scenario when the rvalue behind the & is a macro input, and then use the span of the rvalue. But it looks like that span is not available in the MIR during borrowck. We have RValue::Ref with a Place that points the the binding, not the binding reference.

[camsteffen]

Using Span::with_ctxt as a compromise.

[camelid]

This new output seems non-ideal, but there's probably not a good way to hide it. I guess it could potentially be useful if/when -Z macro-backtrace is stabilized?

[camsteffen]

Not great but there are other instances like this.

[camsteffen]

@m-ou-se can I bother you for a review? The wrong span context is causing surprising behavior in Clippy.

[m-ou-se]

Oh, sorry for the delay.

I don't think I'm the right person to review this though.

Maybe someone from the compiler team?

r? rust-lang/compiler

[cjgillot]

Since the AddrOf node is created by the macro, the macro context indeed seems like the right one.
@bors r+

[bors]

📌 Commit 4cfb7ad has been approved by cjgillot

[bors]

⌛ Testing commit 4cfb7ad with merge 8d6f1889b234af193a3700ec9b8f2064bcd81f63...

[rust-log-analyzer]

The job i686-msvc-1 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

* highest error code: E0786
Found 502 error codes
Found 0 error codes with no tests
Done!
thread '<unnamed>' panicked at 'cmd.exec() failed with Error during execution of `cargo metadata`:     Updating git repository `https://github.com/bjorn3/rust-ar.git`
warning: spurious network error (2 tries remaining): request failed with status code: 504; class=Http (34)
warning: spurious network error (1 tries remaining): request failed with status code: 504; class=Http (34)
error: failed to get `ar` as a dependency of package `rustc_codegen_cranelift v0.1.0 (D:\a\rust\rust\compiler\rustc_codegen_cranelift)`
Caused by:
  failed to load source for dependency `ar`

Caused by:
Caused by:
  Unable to update https://github.com/bjorn3/rust-ar.git?branch=do_not_remove_cg_clif_ranlib#de9ab0e5

Caused by:
  failed to clone into: C:\Users\runneradmin\.cargo\git\db\rust-ar-9b35aff8ad678e06
Caused by:
  network failure seems to have happened
  network failure seems to have happened
  if a proxy or similar is necessary `net.git-fetch-with-cli` may help here
  https://doc.rust-lang.org/cargo/reference/config.html#netgit-fetch-with-cli
Caused by:
Caused by:
  request failed with status code: 504; class=Http (34)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Any { .. }', src\tools\tidy\src/main.rs:77:9


command did not execute successfully: "D:\\a\\rust\\rust\\build\\i686-pc-windows-msvc\\stage0-tools-bin\\rust-tidy.exe" "D:\\a\\rust\\rust" "\\\\?\\D:\\a\\rust\\rust\\build\\i686-pc-windows-msvc\\stage0\\bin\\cargo.exe" "D:\\a\\rust\\rust\\build" "8"


Build completed unsuccessfully in 0:03:55
Build completed unsuccessfully in 0:03:55
make: *** [Makefile:72: ci-subset-1] Error 1

[bors]

💔 Test failed - checks-actions

[camelid]

@bors retry

[bors]

⌛ Testing commit 4cfb7ad with merge c8b3a2be048338a8aff2389252c33c9e01493415...

[bors]

💔 Test failed - checks-actions

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[cjgillot]

@bors retry