Rollup merge of #101731 - notriddle:notriddle/more-improved-html-check, r=GuillaumeGomez

rustdoc: improve rustdoc HTML suggestions handling of nested generics

Based on some poor suggestions produced when stablizing this lint and running it on `manformed-generics.rs` in #101720

5 files changed, 250 insertions, 10 deletions

diff --git a/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.rs b/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.rs
index 744b3071f1b..476e3b2d43e 100644
--- a/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.rs
+++ b/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.rs
@@ -8,6 +8,48 @@ pub struct ConstGeneric;
 // HTML tags cannot contain commas, so no error.
 pub struct MultipleGenerics;
 
+/// This <[u32] as Iterator<Item>> thing!
+//~^ERROR unclosed HTML tag `Item`
+// Some forms of fully-qualified path are simultaneously valid HTML tags
+// with attributes. They produce an error, but no suggestion, because figuring
+// out if this is valid would require parsing the entire path grammar.
+//
+// The important part is that we don't produce any *wrong* suggestions.
+// While several other examples below are added to make sure we don't
+// produce suggestions when given complex paths, this example is the actual
+// reason behind not just using the real path parser. It's ambiguous: there's
+// no way to locally reason out whether that `[u32]` is intended to be a slice
+// or an intra-doc link.
+pub struct FullyQualifiedPathsDoNotCount;
+
+/// This <Vec as IntoIter>::Iter thing!
+//~^ERROR unclosed HTML tag `Vec`
+// Some forms of fully-qualified path are simultaneously valid HTML tags
+// with attributes. They produce an error, but no suggestion, because figuring
+// out if this is valid would require parsing the entire path grammar.
+pub struct FullyQualifiedPathsDoNotCount1;
+
+/// This Vec<Vec as IntoIter>::Iter thing!
+//~^ERROR unclosed HTML tag `Vec`
+// Some forms of fully-qualified path are simultaneously valid HTML tags
+// with attributes. They produce an error, but no suggestion, because figuring
+// out if this is valid would require parsing the entire path grammar.
+pub struct FullyQualifiedPathsDoNotCount2;
+
+/// This Vec<Vec as IntoIter> thing!
+//~^ERROR unclosed HTML tag `Vec`
+// Some forms of fully-qualified path are simultaneously valid HTML tags
+// with attributes. They produce an error, but no suggestion, because figuring
+// out if this is valid would require parsing the entire path grammar.
+pub struct FullyQualifiedPathsDoNotCount3;
+
+/// This Vec<Vec<i32> as IntoIter> thing!
+//~^ERROR unclosed HTML tag `i32`
+// Some forms of fully-qualified path are simultaneously valid HTML tags
+// with attributes. They produce an error, but no suggestion, because figuring
+// out if this is valid would require parsing the entire path grammar.
+pub struct FullyQualifiedPathsDoNotCount4;
+
 /// This Vec<i32 class="test"> thing!
 //~^ERROR unclosed HTML tag `i32`
 // HTML attributes shouldn't be treated as Rust syntax, so no suggestions.
diff --git a/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.stderr b/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.stderr
index 832b8b2cac7..3856a251321 100644
--- a/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.stderr
+++ b/src/test/rustdoc-ui/suggestions/html-as-generics-no-suggestions.stderr
@@ -1,8 +1,8 @@
-error: unclosed HTML tag `i32`
-  --> $DIR/html-as-generics-no-suggestions.rs:11:13
+error: unclosed HTML tag `Item`
+  --> $DIR/html-as-generics-no-suggestions.rs:11:28
    |
-LL | /// This Vec<i32 class="test"> thing!
-   |             ^^^^
+LL | /// This <[u32] as Iterator<Item>> thing!
+   |                            ^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/html-as-generics-no-suggestions.rs:1:9
@@ -10,29 +10,59 @@ note: the lint level is defined here
 LL | #![deny(rustdoc::invalid_html_tags)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+error: unclosed HTML tag `Vec`
+  --> $DIR/html-as-generics-no-suggestions.rs:25:10
+   |
+LL | /// This <Vec as IntoIter>::Iter thing!
+   |          ^^^^
+
+error: unclosed HTML tag `Vec`
+  --> $DIR/html-as-generics-no-suggestions.rs:32:13
+   |
+LL | /// This Vec<Vec as IntoIter>::Iter thing!
+   |             ^^^^
+
+error: unclosed HTML tag `Vec`
+  --> $DIR/html-as-generics-no-suggestions.rs:39:13
+   |
+LL | /// This Vec<Vec as IntoIter> thing!
+   |             ^^^^
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics-no-suggestions.rs:46:17
+   |
+LL | /// This Vec<Vec<i32> as IntoIter> thing!
+   |                 ^^^^^
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics-no-suggestions.rs:53:13
+   |
+LL | /// This Vec<i32 class="test"> thing!
+   |             ^^^^
+
 error: unopened HTML tag `i32`
-  --> $DIR/html-as-generics-no-suggestions.rs:20:13
+  --> $DIR/html-as-generics-no-suggestions.rs:62:13
    |
 LL | /// This Vec</i32> thing!
    |             ^^^^^^
 
 error: unclosed HTML tag `i32`
-  --> $DIR/html-as-generics-no-suggestions.rs:25:13
+  --> $DIR/html-as-generics-no-suggestions.rs:67:13
    |
 LL | /// This 123<i32> thing!
    |             ^^^^^
 
 error: unclosed HTML tag `i32`
-  --> $DIR/html-as-generics-no-suggestions.rs:30:14
+  --> $DIR/html-as-generics-no-suggestions.rs:72:14
    |
 LL | /// This Vec:<i32> thing!
    |              ^^^^^
 
 error: unclosed HTML tag `i32`
-  --> $DIR/html-as-generics-no-suggestions.rs:35:39
+  --> $DIR/html-as-generics-no-suggestions.rs:77:39
    |
 LL | /// This [link](https://rust-lang.org)<i32> thing!
    |                                       ^^^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 10 previous errors
 
diff --git a/src/test/rustdoc-ui/suggestions/html-as-generics.fixed b/src/test/rustdoc-ui/suggestions/html-as-generics.fixed
index c0a0de24c52..07c8c9ff254 100644
--- a/src/test/rustdoc-ui/suggestions/html-as-generics.fixed
+++ b/src/test/rustdoc-ui/suggestions/html-as-generics.fixed
@@ -30,3 +30,43 @@ pub struct BareTurbofish;
 //~^ERROR unclosed HTML tag `i32`
 //~|HELP try marking as source
 pub struct Nested;
+
+/// Nested generics `Vec<Vec<u32>>`
+//~^ ERROR unclosed HTML tag `u32`
+//~|HELP try marking as source
+pub struct NestedGenerics;
+
+/// Generics with path `Vec<i32>::Iter`
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct GenericsWithPath;
+
+/// Generics with path `<Vec<i32>>::Iter`
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPath;
+
+/// Generics with path `Vec<Vec<i32>>::Iter`
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPath2;
+
+/// Generics with bump `<Vec<i32>>`s
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithBump;
+
+/// Generics with bump `Vec<Vec<i32>>`s
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithBump2;
+
+/// Generics with punct `<Vec<i32>>`!
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPunct;
+
+/// Generics with punct `Vec<Vec<i32>>`!
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPunct2;
diff --git a/src/test/rustdoc-ui/suggestions/html-as-generics.rs b/src/test/rustdoc-ui/suggestions/html-as-generics.rs
index 0b6009b0e59..cdd652f397e 100644
--- a/src/test/rustdoc-ui/suggestions/html-as-generics.rs
+++ b/src/test/rustdoc-ui/suggestions/html-as-generics.rs
@@ -30,3 +30,43 @@ pub struct BareTurbofish;
 //~^ERROR unclosed HTML tag `i32`
 //~|HELP try marking as source
 pub struct Nested;
+
+/// Nested generics Vec<Vec<u32>>
+//~^ ERROR unclosed HTML tag `u32`
+//~|HELP try marking as source
+pub struct NestedGenerics;
+
+/// Generics with path Vec<i32>::Iter
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct GenericsWithPath;
+
+/// Generics with path <Vec<i32>>::Iter
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPath;
+
+/// Generics with path Vec<Vec<i32>>::Iter
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPath2;
+
+/// Generics with bump <Vec<i32>>s
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithBump;
+
+/// Generics with bump Vec<Vec<i32>>s
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithBump2;
+
+/// Generics with punct <Vec<i32>>!
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPunct;
+
+/// Generics with punct Vec<Vec<i32>>!
+//~^ ERROR unclosed HTML tag `i32`
+//~|HELP try marking as source
+pub struct NestedGenericsWithPunct2;
diff --git a/src/test/rustdoc-ui/suggestions/html-as-generics.stderr b/src/test/rustdoc-ui/suggestions/html-as-generics.stderr
index df54b71264e..211dd4210d5 100644
--- a/src/test/rustdoc-ui/suggestions/html-as-generics.stderr
+++ b/src/test/rustdoc-ui/suggestions/html-as-generics.stderr
@@ -69,5 +69,93 @@ help: try marking as source code
 LL | /// This <span>`Vec::<i32>`</span> thing!
    |                +          +
 
-error: aborting due to 6 previous errors
+error: unclosed HTML tag `u32`
+  --> $DIR/html-as-generics.rs:34:28
+   |
+LL | /// Nested generics Vec<Vec<u32>>
+   |                            ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Nested generics `Vec<Vec<u32>>`
+   |                     +             +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:39:27
+   |
+LL | /// Generics with path Vec<i32>::Iter
+   |                           ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with path `Vec<i32>::Iter`
+   |                        +              +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:44:28
+   |
+LL | /// Generics with path <Vec<i32>>::Iter
+   |                            ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with path `<Vec<i32>>::Iter`
+   |                        +                +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:49:31
+   |
+LL | /// Generics with path Vec<Vec<i32>>::Iter
+   |                               ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with path `Vec<Vec<i32>>::Iter`
+   |                        +                   +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:54:28
+   |
+LL | /// Generics with bump <Vec<i32>>s
+   |                            ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with bump `<Vec<i32>>`s
+   |                        +          +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:59:31
+   |
+LL | /// Generics with bump Vec<Vec<i32>>s
+   |                               ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with bump `Vec<Vec<i32>>`s
+   |                        +             +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:64:29
+   |
+LL | /// Generics with punct <Vec<i32>>!
+   |                             ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with punct `<Vec<i32>>`!
+   |                         +          +
+
+error: unclosed HTML tag `i32`
+  --> $DIR/html-as-generics.rs:69:32
+   |
+LL | /// Generics with punct Vec<Vec<i32>>!
+   |                                ^^^^^
+   |
+help: try marking as source code
+   |
+LL | /// Generics with punct `Vec<Vec<i32>>`!
+   |                         +             +
+
+error: aborting due to 14 previous errors