On generic and lifetime removal suggestion, do not leave behind stray ,

Author: estebank

compiler/rustc_hir_analysis/src/structured_errors/wrong_number_of_generic_args.rs

@@ -942,17 +942,20 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
                 }
             }
 
-            let span_lo_redundant_lt_args = lt_arg_spans[self.num_expected_lifetime_args()];
+            let span_lo_redundant_lt_args = if self.num_expected_lifetime_args() == 0 {
+                lt_arg_spans[0]
+            } else {
+                lt_arg_spans[self.num_expected_lifetime_args() - 1]
+            };
             let span_hi_redundant_lt_args = lt_arg_spans[lt_arg_spans.len() - 1];
 
-            let span_redundant_lt_args = span_lo_redundant_lt_args.to(span_hi_redundant_lt_args);
+            let span_redundant_lt_args =
+                span_lo_redundant_lt_args.shrink_to_hi().to(span_hi_redundant_lt_args);
             debug!("span_redundant_lt_args: {:?}", span_redundant_lt_args);
 
             let num_redundant_lt_args = lt_arg_spans.len() - self.num_expected_lifetime_args();
-            let msg_lifetimes = format!(
-                "remove the lifetime argument{s}",
-                s = pluralize!(num_redundant_lt_args),
-            );
+            let msg_lifetimes =
+                format!("remove the lifetime argument{s}", s = pluralize!(num_redundant_lt_args));
 
             err.span_suggestion_verbose(
                 span_redundant_lt_args,
@@ -981,11 +984,16 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
             }
 
             let span_lo_redundant_type_or_const_args =
-                gen_arg_spans[self.num_expected_type_or_const_args()];
+                if self.num_expected_type_or_const_args() == 0 {
+                    gen_arg_spans[0]
+                } else {
+                    gen_arg_spans[self.num_expected_type_or_const_args() - 1]
+                };
             let span_hi_redundant_type_or_const_args = gen_arg_spans[gen_arg_spans.len() - 1];
+            let span_redundant_type_or_const_args = span_lo_redundant_type_or_const_args
+                .shrink_to_hi()
+                .to(span_hi_redundant_type_or_const_args);
 
-            let span_redundant_type_or_const_args =
-                span_lo_redundant_type_or_const_args.to(span_hi_redundant_type_or_const_args);
             debug!("span_redundant_type_or_const_args: {:?}", span_redundant_type_or_const_args);
 
             let num_redundant_gen_args =

tests/rustdoc-ui/mismatched_arg_count.stderr

@@ -12,7 +12,7 @@ LL | type Alias<'a, T> = <T as Trait<'a>>::Assoc;
 help: remove the lifetime argument
    |
 LL - fn bar<'a, T: Trait<'a>>(_: Alias<'a, 'a, T>) {}
-LL + fn bar<'a, T: Trait<'a>>(_: Alias<'a, , T>) {}
+LL + fn bar<'a, T: Trait<'a>>(_: Alias<'a, T>) {}
    |
 
 error: aborting due to 1 previous error

tests/ui/const-generics/adt_const_params/transmutable-ice-110969.stderr

@@ -7,7 +7,7 @@ LL |         Dst: BikeshedIntrinsicFrom<Src, Context, ASSUME>,
 help: remove the unnecessary generic argument
    |
 LL -         Dst: BikeshedIntrinsicFrom<Src, Context, ASSUME>,
-LL +         Dst: BikeshedIntrinsicFrom<Src, Context, >,
+LL +         Dst: BikeshedIntrinsicFrom<Src, Context>,
    |
 
 error[E0308]: mismatched types

tests/ui/const-generics/generic_arg_infer/infer-arg-test.stderr

@@ -33,7 +33,7 @@ LL | struct All<'a, T, const N: usize> {
 help: remove the unnecessary generic argument
    |
 LL -   let a: All<_, _, _>;
-LL +   let a: All<_, _, >;
+LL +   let a: All<_, _>;
    |
 
 error: aborting due to 4 previous errors

tests/ui/const-generics/generic_const_exprs/const_kind_expr/issue_114151.stderr

@@ -12,7 +12,7 @@ LL | fn foo<const N: usize>(
 help: remove the unnecessary generic argument
    |
 LL -     foo::<_, L>([(); L + 1 + L]);
-LL +     foo::<_, >([(); L + 1 + L]);
+LL +     foo::<_>([(); L + 1 + L]);
    |
 
 error[E0308]: mismatched types

tests/ui/const-generics/incorrect-number-of-const-args.stderr

@@ -30,7 +30,7 @@ LL | fn foo<const X: usize, const Y: usize>() -> usize {
 help: remove the unnecessary generic argument
    |
 LL -     foo::<0, 0, 0>();
-LL +     foo::<0, 0, >();
+LL +     foo::<0, 0>();
    |
 
 error: aborting due to 2 previous errors

tests/ui/const-generics/invalid-constant-in-args.stderr

@@ -7,7 +7,7 @@ LL |     let _: Cell<&str, "a"> = Cell::new("");
 help: remove the unnecessary generic argument
    |
 LL -     let _: Cell<&str, "a"> = Cell::new("");
-LL +     let _: Cell<&str, > = Cell::new("");
+LL +     let _: Cell<&str> = Cell::new("");
    |
 
 error: aborting due to 1 previous error

tests/ui/constructor-lifetime-args.stderr

@@ -30,7 +30,7 @@ LL | struct S<'a, 'b>(&'a u8, &'b u8);
 help: remove the lifetime argument
    |
 LL -     S::<'static, 'static, 'static>(&0, &0);
-LL +     S::<'static, 'static, >(&0, &0);
+LL +     S::<'static, 'static>(&0, &0);
    |
 
 error[E0107]: enum takes 2 lifetime arguments but 1 lifetime argument was supplied
@@ -65,7 +65,7 @@ LL | enum E<'a, 'b> {
 help: remove the lifetime argument
    |
 LL -     E::V::<'static, 'static, 'static>(&0);
-LL +     E::V::<'static, 'static, >(&0);
+LL +     E::V::<'static, 'static>(&0);
    |
 
 error: aborting due to 4 previous errors

tests/ui/error-codes/E0107.stderr

@@ -47,7 +47,7 @@ LL | struct Foo<'a>(&'a str);
 help: remove the lifetime arguments
    |
 LL -     foo2: Foo<'a, 'b, 'c>,
-LL +     foo2: Foo<'a, >,
+LL +     foo2: Foo<'a>,
    |
 
 error[E0107]: struct takes 1 lifetime argument but 2 lifetime arguments were supplied
@@ -64,7 +64,7 @@ LL | struct Qux<'a, T>(&'a T);
 help: remove the lifetime argument
    |
 LL -     qux1: Qux<'a, 'b, i32>,
-LL +     qux1: Qux<'a, , i32>,
+LL +     qux1: Qux<'a, i32>,
    |
 
 error[E0107]: struct takes 1 lifetime argument but 2 lifetime arguments were supplied
@@ -81,7 +81,7 @@ LL | struct Qux<'a, T>(&'a T);
 help: remove the lifetime argument
    |
 LL -     qux2: Qux<'a, i32, 'b>,
-LL +     qux2: Qux<'a, i32, >,
+LL +     qux2: Qux<'a>,
    |
 
 error[E0107]: struct takes 1 lifetime argument but 3 lifetime arguments were supplied
@@ -98,7 +98,7 @@ LL | struct Qux<'a, T>(&'a T);
 help: remove the lifetime arguments
    |
 LL -     qux3: Qux<'a, 'b, 'c, i32>,
-LL +     qux3: Qux<'a, , i32>,
+LL +     qux3: Qux<'a, i32>,
    |
 
 error[E0107]: struct takes 1 lifetime argument but 3 lifetime arguments were supplied
@@ -115,7 +115,7 @@ LL | struct Qux<'a, T>(&'a T);
 help: remove the lifetime arguments
    |
 LL -     qux4: Qux<'a, i32, 'b, 'c>,
-LL +     qux4: Qux<'a, i32, >,
+LL +     qux4: Qux<'a>,
    |
 
 error[E0107]: struct takes 1 lifetime argument but 3 lifetime arguments were supplied
@@ -132,7 +132,7 @@ LL | struct Qux<'a, T>(&'a T);
 help: remove the lifetime argument
    |
 LL -     qux5: Qux<'a, 'b, i32, 'c>,
-LL +     qux5: Qux<'a, , i32, 'c>,
+LL +     qux5: Qux<'a, i32, 'c>,
    |
 
 error[E0107]: struct takes 0 lifetime arguments but 2 lifetime arguments were supplied

tests/ui/generic-associated-types/parameter_number_and_kind.stderr

@@ -12,7 +12,7 @@ LL |     type E<'a, T>;
 help: remove the lifetime argument
    |
 LL -     type FErr1 = Self::E<'static, 'static>;
-LL +     type FErr1 = Self::E<'static, >;
+LL +     type FErr1 = Self::E<'static>;
    |
 
 error[E0107]: associated type takes 1 generic argument but 0 generic arguments were supplied
@@ -45,7 +45,7 @@ LL |     type E<'a, T>;
 help: remove the unnecessary generic argument
    |
 LL -     type FErr2<T> = Self::E<'static, T, u32>;
-LL +     type FErr2<T> = Self::E<'static, T, >;
+LL +     type FErr2<T> = Self::E<'static, T>;
    |
 
 error: aborting due to 3 previous errors

tests/ui/generics/bad-mid-path-type-params.stderr

@@ -12,7 +12,7 @@ LL |     fn new<U>(x: T, _: U) -> S<T> {
 help: remove the unnecessary generic argument
    |
 LL -     let _ = S::new::<isize,f64>(1, 1.0);
-LL +     let _ = S::new::<isize,>(1, 1.0);
+LL +     let _ = S::new::<isize>(1, 1.0);
    |
 
 error[E0107]: struct takes 0 lifetime arguments but 1 lifetime argument was supplied
@@ -46,7 +46,7 @@ LL |     fn new<U>(x: T, y: U) -> Self;
 help: remove the unnecessary generic argument
    |
 LL -     let _: S2 = Trait::new::<isize,f64>(1, 1.0);
-LL +     let _: S2 = Trait::new::<isize,>(1, 1.0);
+LL +     let _: S2 = Trait::new::<isize>(1, 1.0);
    |
 
 error[E0107]: trait takes 0 lifetime arguments but 1 lifetime argument was supplied
@@ -80,7 +80,7 @@ LL |     fn new<U>(x: T, y: U) -> Self;
 help: remove the unnecessary generic argument
    |
 LL -     let _: S2 = Trait::<'a,isize>::new::<f64,f64>(1, 1.0);
-LL +     let _: S2 = Trait::<'a,isize>::new::<f64,>(1, 1.0);
+LL +     let _: S2 = Trait::<'a,isize>::new::<f64>(1, 1.0);
    |
 
 error: aborting due to 5 previous errors

tests/ui/generics/foreign-generic-mismatch.stderr

@@ -30,7 +30,7 @@ LL | pub fn lt_arg<'a: 'a>() {}
 help: remove the lifetime argument
    |
 LL -     foreign_generic_mismatch::lt_arg::<'static, 'static>();
-LL +     foreign_generic_mismatch::lt_arg::<'static, >();
+LL +     foreign_generic_mismatch::lt_arg::<'static>();
    |
 
 error: aborting due to 2 previous errors

tests/ui/generics/generic-arg-mismatch-recover.stderr

@@ -12,7 +12,7 @@ LL | struct Foo<'a, T: 'a>(&'a T);
 help: remove the lifetime argument
    |
 LL -     Foo::<'static, 'static, ()>(&0);
-LL +     Foo::<'static, , ()>(&0);
+LL +     Foo::<'static, ()>(&0);
    |
 
 error[E0107]: struct takes 1 lifetime argument but 2 lifetime arguments were supplied
@@ -29,7 +29,7 @@ LL | struct Bar<'a>(&'a ());
 help: remove the lifetime argument
    |
 LL -     Bar::<'static, 'static, ()>(&());
-LL +     Bar::<'static, , ()>(&());
+LL +     Bar::<'static, ()>(&());
    |
 
 error[E0107]: struct takes 0 generic arguments but 1 generic argument was supplied

tests/ui/generics/generic-impl-more-params-with-defaults.stderr

@@ -12,7 +12,7 @@ LL | struct Vec<T, A = Heap>(
 help: remove the unnecessary generic argument
    |
 LL -     Vec::<isize, Heap, bool>::new();
-LL +     Vec::<isize, Heap, >::new();
+LL +     Vec::<isize, Heap>::new();
    |
 
 error: aborting due to 1 previous error

tests/ui/generics/generic-type-more-params-with-defaults.stderr

@@ -12,7 +12,7 @@ LL | struct Vec<T, A = Heap>(
 help: remove the unnecessary generic argument
    |
 LL -     let _: Vec<isize, Heap, bool>;
-LL +     let _: Vec<isize, Heap, >;
+LL +     let _: Vec<isize, Heap>;
    |
 
 error: aborting due to 1 previous error