Use spans pointing at the inside of a rustdoc attribute

[estebank]

Follow up to #51111.

Point to the link in a rustdoc attribute where intralink resolution failed, instead of the full rustdoc attribute's span.

r? @GuillaumeGomez cc @kennytm

[GuillaumeGomez]

Awesome! Once ci fixed, r=me

[kennytm]

@estebank Could you verify how this works for all kinds of doc comments:

#![feature(external_doc)]

/// Foo
/// bar [BarA] bar
/// baz
pub fn a() {}

/**
 * Foo
 * bar [BarB] bar
 * baz
 */
pub fn b() {}

/** Foo

bar [BarC] bar
baz

    let bar_c_1 = 0;
    let bar_c_2 = 0;
    let g = [bar_c_1];
    let h = g[bar_c_2];

*/
pub fn c() {}

#[doc = "Foo\nbar [BarD] bar\nbaz"]
pub fn d() {}

#[doc(include = "file.md")]
pub fn e() {}

macro_rules! f {
    ($f:expr) => {
        #[doc = $f]
        pub fn f() {}
    }
}
f!("Foo\nbar [BarF] bar\nbaz");

Here the content of file.md is

Foo
bar [BarE] bar
baz

For reference, the existing output post-51111

warning: [BarA] cannot be resolved, ignoring it...
 --> 1.rs:3:1
  |
3 | / /// Foo
4 | | /// bar [BarA] bar
5 | | /// baz
  | |_______^
  |
  = note: the link appears in this line:
          
           bar [BarA] bar
                ^^^^

warning: [BarB] cannot be resolved, ignoring it...
  --> 1.rs:8:1
   |
8  | / /**
9  | |  * Foo
10 | |  * bar [BarB] bar
11 | |  * baz
12 | |  */
   | |___^
   |
   = note: the link appears in this line:
           
            bar [BarB] bar
                 ^^^^

warning: [BarC] cannot be resolved, ignoring it...
  --> 1.rs:15:1
   |
15 | / /** Foo
16 | |
17 | | bar [BarC] bar
18 | | baz
...  |
24 | |
25 | | */
   | |__^
   |
   = note: the link appears in this line:
           
           bar [BarC] bar
                ^^^^

warning: [BarD] cannot be resolved, ignoring it...
  --> 1.rs:28:1
   |
28 | #[doc = "Foo\nbar [BarD] bar\nbaz"]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: the link appears in this line:
           
           bar [BarD] bar
                ^^^^

warning: [BarE] cannot be resolved, ignoring it...
  --> 1.rs:31:1
   |
31 | #[doc(include = "file.md")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: the link appears in this line:
           
           bar [BarE] bar
                ^^^^

warning: [BarF] cannot be resolved, ignoring it...
  --> 1.rs:36:9
   |
36 |         #[doc = $f]
   |         ^^^^^^^^^^^
...
40 | f!("Foo\nbar [BarF] bar\nbaz");
   | ------------------------------- in this macro invocation
   |
   = note: the link appears in this line:
           
           bar [BarF] bar
                ^^^^

[estebank]

@kennytm modified the code to fallback to the current behavior if the line count of the docs don't match the line count of the code. This uses the new spans for the /// doc comments but keeps the current behavior for all others. I also fixed the problem of different leading whitespace on different lines messing up the spans.

[kennytm]

You could use

let sp = sp.from_inner_byte_pos(
    link_range.start + code_dox_len, 
    link_range.end + code_dox_len,
);

here 😃

https://doc.rust-lang.org/nightly/nightly-rustc/syntax_pos/struct.Span.html#method.from_inner_byte_pos

[estebank]

@bors r=GuillaumeGomez

[bors]

📌 Commit 31bb50b has been approved by GuillaumeGomez

[bors]

🌲 The tree is currently closed for pull requests below priority 10, this pull request will be tested once the tree is reopened

[bors]

⌛ Testing commit 31bb50b with merge bdc515addf0bed215a5581c6d2d5fe90aca612fd...

[bors]

💔 Test failed - status-appveyor

[kennytm]

@bors retry

Why closing the tree would cancel the existing PR? 😕