Do not suggest introducing new binding when other suggestions are present

Author: estebank

compiler/rustc_errors/src/lib.rs

@@ -138,6 +138,14 @@ impl Suggestions {
             Suggestions::Disabled => Vec::new(),
         }
     }
+
+    pub fn len(&self) -> usize {
+        match self {
+            Suggestions::Enabled(suggestions) => suggestions.len(),
+            Suggestions::Sealed(suggestions) => suggestions.len(),
+            Suggestions::Disabled => 0,
+        }
+    }
 }
 
 impl Default for Suggestions {

compiler/rustc_hir_typeck/src/pat.rs

@@ -1644,7 +1644,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 return;
             }
         };
-        if let [hir::PathSegment { ident, args: None, .. }] = segments {
+        if let [hir::PathSegment { ident, args: None, .. }] = segments
+            && e.suggestions.len() == 0
+        {
             e.span_label(span, format!("{} defined here", res.descr()));
             e.span_label(
                 pat_span,

tests/ui/did_you_mean/compatible-variants-in-pat.rs

@@ -21,7 +21,6 @@ fn b(s: Option<S>) {
         S => {
             //~^ ERROR mismatched types
             //~| HELP try wrapping
-            //~| HELP introduce a new binding instead
         }
         _ => {}
     }
@@ -32,7 +31,6 @@ fn c(s: Result<S, S>) {
         S => {
             //~^ ERROR mismatched types
             //~| HELP try wrapping
-            //~| HELP introduce a new binding instead
         }
         _ => {}
     }

tests/ui/did_you_mean/compatible-variants-in-pat.stderr

@@ -14,42 +14,25 @@ LL |         Foo::Bar(Bar { x }) => {
 error[E0308]: mismatched types
   --> $DIR/compatible-variants-in-pat.rs:21:9
    |
-LL | struct S;
-   | -------- unit struct defined here
-...
 LL |     match s {
    |           - this expression has type `Option<S>`
 LL |         S => {
-   |         ^
-   |         |
-   |         expected `Option<S>`, found `S`
-   |         `S` is interpreted as a unit struct, not a new binding
+   |         ^ expected `Option<S>`, found `S`
    |
    = note: expected enum `Option<S>`
             found struct `S`
 help: try wrapping the pattern in `Some`
    |
 LL |         Some(S) => {
    |         +++++ +
-help: introduce a new binding instead
-   |
-LL -         S => {
-LL +         other_s => {
-   |
 
 error[E0308]: mismatched types
-  --> $DIR/compatible-variants-in-pat.rs:32:9
+  --> $DIR/compatible-variants-in-pat.rs:31:9
    |
-LL | struct S;
-   | -------- unit struct defined here
-...
 LL |     match s {
    |           - this expression has type `Result<S, S>`
 LL |         S => {
-   |         ^
-   |         |
-   |         expected `Result<S, S>`, found `S`
-   |         `S` is interpreted as a unit struct, not a new binding
+   |         ^ expected `Result<S, S>`, found `S`
    |
    = note: expected enum `Result<S, S>`
             found struct `S`
@@ -59,11 +42,6 @@ LL |         Ok(S) => {
    |         +++ +
 LL |         Err(S) => {
    |         ++++ +
-help: introduce a new binding instead
-   |
-LL -         S => {
-LL +         other_s => {
-   |
 
 error: aborting due to 3 previous errors
 

tests/ui/match/issue-12552.stderr

@@ -20,26 +20,14 @@ LL |   match t {
    |         - this expression has type `Result<_, {integer}>`
 ...
 LL |     None => ()
-   |     ^^^^
-   |     |
-   |     expected `Result<_, {integer}>`, found `Option<_>`
-   |     `None` is interpreted as a unit variant, not a new binding
-   |
-  --> $SRC_DIR/core/src/option.rs:LL:COL
-   |
-   = note: unit variant defined here
+   |     ^^^^ expected `Result<_, {integer}>`, found `Option<_>`
    |
    = note: expected enum `Result<_, {integer}>`
               found enum `Option<_>`
 help: try wrapping the pattern in `Ok`
    |
 LL |     Ok(None) => ()
    |     +++    +
-help: introduce a new binding instead
-   |
-LL -     None => ()
-LL +     other_none => ()
-   |
 
 error: aborting due to 2 previous errors
 

tests/ui/suggestions/suggest-deref-in-match-issue-132784.rs

@@ -8,7 +8,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     match &x {
@@ -18,7 +17,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     let mut y = Box::new(Some(1));
@@ -29,7 +27,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     let mut z = Arc::new(Some(1));
@@ -40,7 +37,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     let z_const: &Arc<Option<i32>> = &z;
@@ -51,7 +47,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     // Normal reference because Arc doesn't implement DerefMut.
@@ -63,7 +58,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     // Mutable reference because Box does implement DerefMut.
@@ -75,7 +69,6 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 
     // Difficult expression.
@@ -87,6 +80,5 @@ fn main() {
         //~^ ERROR mismatched types
         None => {}
         //~^ ERROR mismatched types
-        //~| HELP introduce a new binding instead
     }
 }