Rollup merge of #117891 - compiler-errors:recover-for-dyn, r=davidtwco

Recover `dyn` and `impl` after `for<...>`

Recover `dyn` and `impl` after `for<...>` in types. Reuses the logic for parsing bare trait objects, so it doesn't fix cases like `for<'a> dyn Trait + dyn Trait` or anything, but that seems somewhat of a different issue.

Parsing recovery logic is a bit involved, but I couldn't find a way to simplify it.

Fixes #117882

2 files changed, 35 insertions, 0 deletions

diff --git a/tests/ui/parser/recover-hrtb-before-dyn-impl-kw.rs b/tests/ui/parser/recover-hrtb-before-dyn-impl-kw.rs
new file mode 100644
index 00000000000..fe363a6887f
--- /dev/null
+++ b/tests/ui/parser/recover-hrtb-before-dyn-impl-kw.rs
@@ -0,0 +1,9 @@
+trait Trait {}
+
+fn test(_: &for<'a> dyn Trait) {}
+//~^ ERROR `for<...>` expected after `dyn`, not before
+
+fn test2(_: for<'a> impl Trait) {}
+//~^ ERROR `for<...>` expected after `impl`, not before
+
+fn main() {}
diff --git a/tests/ui/parser/recover-hrtb-before-dyn-impl-kw.stderr b/tests/ui/parser/recover-hrtb-before-dyn-impl-kw.stderr
new file mode 100644
index 00000000000..6fc1259b910
--- /dev/null
+++ b/tests/ui/parser/recover-hrtb-before-dyn-impl-kw.stderr
@@ -0,0 +1,26 @@
+error: `for<...>` expected after `dyn`, not before
+  --> $DIR/recover-hrtb-before-dyn-impl-kw.rs:3:21
+   |
+LL | fn test(_: &for<'a> dyn Trait) {}
+   |                     ^^^
+   |
+help: move `dyn` before the `for<...>`
+   |
+LL - fn test(_: &for<'a> dyn Trait) {}
+LL + fn test(_: &dyn for<'a> Trait) {}
+   |
+
+error: `for<...>` expected after `impl`, not before
+  --> $DIR/recover-hrtb-before-dyn-impl-kw.rs:6:21
+   |
+LL | fn test2(_: for<'a> impl Trait) {}
+   |                     ^^^^
+   |
+help: move `impl` before the `for<...>`
+   |
+LL - fn test2(_: for<'a> impl Trait) {}
+LL + fn test2(_: impl for<'a> Trait) {}
+   |
+
+error: aborting due to 2 previous errors
+