Rustdoc omits source line numbers in diagnostics if they originate in a macro

[jyn514]

I tried this code:

rust/compiler/rustc_session/src/options.rs

Lines 97 to 104 in 9d170be

	top_level_options!(
	/// The top-level command-line options struct.
	///
	/// For each option, one has to specify how it behaves with regard to the
	/// dependency tracking system of incremental compilation. This is done via the
	/// square-bracketed directive after the field type. The options are:
	///
	/// [TRACKED]

I expected to see this happen: Rustdoc shows the line number of the broken link, like it does normally:

warning: unresolved link to `x`
 --> src/lib.rs:1:6
  |
1 | //! [x]
  |      ^ no item named `x` in scope
  |
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

Instead, this happened:

 Documenting rustc_session v0.0.0 (/checkout/compiler/rustc_session)
error: unresolved link to `TRACKED`
   --> compiler/rustc_session/src/options.rs:61:12
    |
61  |           $( #[$top_level_attr] )*
...
...
97  | / top_level_options!(
99  | |     ///
99  | |     ///
100 | |     /// For each option, one has to specify how it behaves with regard to the
201 | |     }
202 | | );
    | |__- in this macro invocation
    |
    |
    = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
    = note: the link appears in this line:
            
            [TRACKED]
             ^^^^^^^
    = note: no item named `TRACKED` in scope
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

Meta

rustc --version --verbose:

Originally posted by @rust-log-analyzer in #84233 (comment)

[jyn514]

I think the fix is to extend source_span_for_markdown_range to work with macros:

rust/src/librustdoc/passes/collect_intra_doc_links.rs

Line 1702 in 78c9639

let span = super::source_span_for_markdown_range(tcx, dox, link_range, &item.attrs);