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Suggest correct order for args and constraints
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3 files changed

+68
-0
lines changed

3 files changed

+68
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lines changed

‎src/librustc_ast_passes/ast_validation.rs

Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -663,6 +663,20 @@ impl<'a> AstValidator<'a> {
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_ => None,
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})
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.collect::<Vec<_>>();
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let snippet_span = match &constraint_spans[..] {
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[single] => *single,
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[first, .., last] => first.to(*last),
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[] => unreachable!(),
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};
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let removal_span = match &arg_spans[..] {
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[first, ..] => snippet_span.until(*first),
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[] => unreachable!(),
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};
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let sugg_span = match &arg_spans[..] {
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[.., last] => last.shrink_to_hi(),
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[] => unreachable!(),
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};
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let snippet = self.session.source_map().span_to_snippet(snippet_span).unwrap();
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let constraint_len = constraint_spans.len();
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// ...and then error:
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self.err_handler()
@@ -679,6 +693,15 @@ impl<'a> AstValidator<'a> {
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),
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)
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.span_labels(arg_spans, "generic argument")
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.multipart_suggestion(
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"move the constraints after the generic arguments",
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vec![
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(removal_span, String::new()),
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(sugg_span.shrink_to_lo(), ", ".to_string()),
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(sugg_span, snippet),
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],
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Applicability::MachineApplicable,
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)
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.emit();
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}
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}

‎src/test/ui/parser/issue-32214.stderr

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Original file line numberDiff line numberDiff line change
@@ -5,6 +5,11 @@ LL | pub fn test<W, I: Trait<Item=(), W> >() {}
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| ------- ^ generic argument
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| |
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| the constraint is provided here
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|
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help: move the constraints after the generic arguments
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|
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LL | pub fn test<W, I: Trait<W, Item=()> >() {}
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| --^^^^^^^
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error: aborting due to previous error
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‎src/test/ui/suggestions/suggest-move-types.stderr

Lines changed: 40 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -5,6 +5,11 @@ LL | struct A<T, M: One<A=(), T>> {
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| ---- ^ generic argument
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| |
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| the constraint is provided here
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|
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help: move the constraints after the generic arguments
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|
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LL | struct A<T, M: One<T, A=()>> {
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| --^^^^
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914
error: generic arguments must come before the first constraint
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--> $DIR/suggest-move-types.rs:33:43
@@ -14,6 +19,11 @@ LL | struct Al<'a, T, M: OneWithLifetime<A=(), T, 'a>> {
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| | |
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| | generic argument
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| the constraint is provided here
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|
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help: move the constraints after the generic arguments
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|
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LL | struct Al<'a, T, M: OneWithLifetime<T, 'a, A=()>> {
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| -- ^^^^
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1828
error: generic arguments must come before the first constraint
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--> $DIR/suggest-move-types.rs:40:46
@@ -26,6 +36,11 @@ LL | struct B<T, U, V, M: Three<A=(), B=(), C=(), T, U, V>> {
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| | | the constraints are provided here
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| | the constraints are provided here
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| the constraints are provided here
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|
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help: move the constraints after the generic arguments
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|
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LL | struct B<T, U, V, M: Three<T, U, V, A=(), B=(), C=()>> {
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| -- ^^^^^^^^^^^^^^^^
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error: generic arguments must come before the first constraint
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--> $DIR/suggest-move-types.rs:48:71
@@ -41,6 +56,11 @@ LL | struct Bl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<A=(), B=(), C=(), T, U,
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| | | the constraints are provided here
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| | the constraints are provided here
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| the constraints are provided here
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|
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help: move the constraints after the generic arguments
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|
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LL | struct Bl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, U, V, 'a, 'b, 'c, A=(), B=(), C=()>> {
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| -- ^^^^^^^^^^^^^^^^
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4565
error: generic arguments must come before the first constraint
4666
--> $DIR/suggest-move-types.rs:57:28
@@ -53,6 +73,11 @@ LL | struct C<T, U, V, M: Three<T, A=(), B=(), C=(), U, V>> {
5373
| | | the constraints are provided here
5474
| | the constraints are provided here
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| generic argument
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|
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help: move the constraints after the generic arguments
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|
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LL | struct C<T, U, V, M: Three<A=(), B=(), C=(), U, V, A=(), B=(), C=()>> {
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| -- ^^^^^^^^^^^^^^^^
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5782
error: generic arguments must come before the first constraint
5883
--> $DIR/suggest-move-types.rs:65:53
@@ -68,6 +93,11 @@ LL | struct Cl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), C=()
6893
| | | the constraints are provided here
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| | generic argument
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| generic argument
96+
|
97+
help: move the constraints after the generic arguments
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|
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LL | struct Cl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<A=(), B=(), C=(), U, 'b, V, 'c, A=(), B=(), C=()>> {
100+
| -- ^^^^^^^^^^^^^^^^
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72102
error: generic arguments must come before the first constraint
73103
--> $DIR/suggest-move-types.rs:74:28
@@ -80,6 +110,11 @@ LL | struct D<T, U, V, M: Three<T, A=(), B=(), U, C=(), V>> {
80110
| | | the constraints are provided here
81111
| | the constraints are provided here
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| generic argument
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|
114+
help: move the constraints after the generic arguments
115+
|
116+
LL | struct D<T, U, V, M: Three<A=(), B=(), U, C=(), V, A=(), B=(), U, C=()>> {
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| -- ^^^^^^^^^^^^^^^^^^^
83118

84119
error: generic arguments must come before the first constraint
85120
--> $DIR/suggest-move-types.rs:82:53
@@ -95,6 +130,11 @@ LL | struct Dl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), U, '
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| | | the constraints are provided here
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| | generic argument
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| generic argument
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|
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help: move the constraints after the generic arguments
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|
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LL | struct Dl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<A=(), B=(), U, 'b, C=(), V, 'c, A=(), B=(), U, 'b, C=()>> {
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| -- ^^^^^^^^^^^^^^^^^^^^^^^
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99139
error[E0747]: type provided when a lifetime was expected
100140
--> $DIR/suggest-move-types.rs:33:43

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