diff --git a/compiler/rustc_typeck/src/check/pat.rs b/compiler/rustc_typeck/src/check/pat.rs index 5fc573a57ad0bac366b511e2242e4f22aec0080a..ecc6e8599ad01d2ccd7e8084fe69b9477f658441 100644 --- a/compiler/rustc_typeck/src/check/pat.rs +++ b/compiler/rustc_typeck/src/check/pat.rs @@ -15,6 +15,7 @@ use rustc_span::lev_distance::find_best_match_for_name; use rustc_span::source_map::{Span, Spanned}; use rustc_span::symbol::Ident; +use rustc_span::{BytePos, DUMMY_SP}; use rustc_trait_selection::traits::{ObligationCause, Pattern}; use std::cmp; @@ -1001,7 +1002,7 @@ fn e0023( // More generally, the expected type wants a tuple variant with one field of an // N-arity-tuple, e.g., `V_i((p_0, .., p_N))`. Meanwhile, the user supplied a pattern // with the subpatterns directly in the tuple variant pattern, e.g., `V_i(p_0, .., p_N)`. - let missing_parenthesis = match (&expected.kind(), fields, had_err) { + let missing_parentheses = match (&expected.kind(), fields, had_err) { // #67037: only do this if we could successfully type-check the expected type against // the tuple struct pattern. Otherwise the substs could get out of range on e.g., // `let P() = U;` where `P != U` with `struct P(T);`. @@ -1014,13 +1015,13 @@ fn e0023( } _ => false, }; - if missing_parenthesis { + if missing_parentheses { let (left, right) = match subpats { // This is the zero case; we aim to get the "hi" part of the `QPath`'s // span as the "lo" and then the "hi" part of the pattern's span as the "hi". // This looks like: // - // help: missing parenthesis + // help: missing parentheses // | // L | let A(()) = A(()); // | ^ ^ @@ -1029,17 +1030,63 @@ fn e0023( // last sub-pattern. In the case of `A(x)` the first and last may coincide. // This looks like: // - // help: missing parenthesis + // help: missing parentheses // | // L | let A((x, y)) = A((1, 2)); // | ^ ^ [first, ..] => (first.span.shrink_to_lo(), subpats.last().unwrap().span), }; err.multipart_suggestion( - "missing parenthesis", + "missing parentheses", vec![(left, "(".to_string()), (right.shrink_to_hi(), ")".to_string())], Applicability::MachineApplicable, ); + } else if fields.len() > subpats.len() { + let after_fields_span = if pat_span == DUMMY_SP { + pat_span + } else { + pat_span.with_hi(pat_span.hi() - BytePos(1)).shrink_to_hi() + }; + let all_fields_span = match subpats { + [] => after_fields_span, + [field] => field.span, + [first, .., last] => first.span.to(last.span), + }; + + // Check if all the fields in the pattern are wildcards. + let all_wildcards = subpats.iter().all(|pat| matches!(pat.kind, PatKind::Wild)); + + let mut wildcard_sugg = vec!["_"; fields.len() - subpats.len()].join(", "); + if !subpats.is_empty() { + wildcard_sugg = String::from(", ") + &wildcard_sugg; + } + + err.span_suggestion_verbose( + after_fields_span, + "use `_` to explicitly ignore each field", + wildcard_sugg, + Applicability::MaybeIncorrect, + ); + + // Only suggest `..` if more than one field is missing + // or the pattern consists of all wildcards. + if fields.len() - subpats.len() > 1 || all_wildcards { + if subpats.is_empty() || all_wildcards { + err.span_suggestion_verbose( + all_fields_span, + "use `..` to ignore all fields", + String::from(".."), + Applicability::MaybeIncorrect, + ); + } else { + err.span_suggestion_verbose( + after_fields_span, + "use `..` to ignore the rest of the fields", + String::from(", .."), + Applicability::MaybeIncorrect, + ); + } + } } err.emit(); diff --git a/src/test/ui/destructuring-assignment/tuple_struct_destructure_fail.stderr b/src/test/ui/destructuring-assignment/tuple_struct_destructure_fail.stderr index 0e7174e5b19d6d4224ef4723f9765e833b8736cc..c270593cac741883fcc242d2961983adb4849b88 100644 --- a/src/test/ui/destructuring-assignment/tuple_struct_destructure_fail.stderr +++ b/src/test/ui/destructuring-assignment/tuple_struct_destructure_fail.stderr @@ -31,6 +31,15 @@ LL | struct TupleStruct(S, T); ... LL | TupleStruct(_) = TupleStruct(1, 2); | ^^^^^^^^^^^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | TupleStruct(_, _) = TupleStruct(1, 2); + | ^^^ +help: use `..` to ignore all fields + | +LL | TupleStruct(..) = TupleStruct(1, 2); + | ^^ error[E0023]: this pattern has 3 fields, but the corresponding tuple variant has 2 fields --> $DIR/tuple_struct_destructure_fail.rs:34:5 @@ -49,6 +58,15 @@ LL | SingleVariant(S, T) ... LL | Enum::SingleVariant(_) = Enum::SingleVariant(1, 2); | ^^^^^^^^^^^^^^^^^^^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | Enum::SingleVariant(_, _) = Enum::SingleVariant(1, 2); + | ^^^ +help: use `..` to ignore all fields + | +LL | Enum::SingleVariant(..) = Enum::SingleVariant(1, 2); + | ^^ error[E0070]: invalid left-hand side of assignment --> $DIR/tuple_struct_destructure_fail.rs:40:12 diff --git a/src/test/ui/error-codes/E0023.stderr b/src/test/ui/error-codes/E0023.stderr index a3610099294dad30d86403c91138084416386a98..832eba69722134f762552a8ab1073de8660d9a29 100644 --- a/src/test/ui/error-codes/E0023.stderr +++ b/src/test/ui/error-codes/E0023.stderr @@ -6,6 +6,11 @@ LL | Apple(String, String), ... LL | Fruit::Apple(a) => {}, | ^^^^^^^^^^^^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | Fruit::Apple(a, _) => {}, + | ^^^ error[E0023]: this pattern has 3 fields, but the corresponding tuple variant has 2 fields --> $DIR/E0023.rs:12:9 @@ -34,7 +39,7 @@ LL | Orange((String, String)), LL | Fruit::Orange(a, b) => {}, | ^^^^^^^^^^^^^^^^^^^ expected 1 field, found 2 | -help: missing parenthesis +help: missing parentheses | LL | Fruit::Orange((a, b)) => {}, | ^ ^ @@ -48,7 +53,7 @@ LL | Banana(()), LL | Fruit::Banana() => {}, | ^^^^^^^^^^^^^^^ expected 1 field, found 0 | -help: missing parenthesis +help: missing parentheses | LL | Fruit::Banana(()) => {}, | ^ ^ diff --git a/src/test/ui/issues/issue-67037-pat-tup-scrut-ty-diff-less-fields.stderr b/src/test/ui/issues/issue-67037-pat-tup-scrut-ty-diff-less-fields.stderr index 6e8ea6bf618f2fdb1a86ba90a83c755a3135326f..9bdbf0bf9f40dfced6ed3e35aea1a6591fb913c0 100644 --- a/src/test/ui/issues/issue-67037-pat-tup-scrut-ty-diff-less-fields.stderr +++ b/src/test/ui/issues/issue-67037-pat-tup-scrut-ty-diff-less-fields.stderr @@ -17,6 +17,15 @@ LL | struct P(T); // 1 type parameter wanted ... LL | let P() = U {}; | ^^^ expected 1 field, found 0 + | +help: use `_` to explicitly ignore each field + | +LL | let P(_) = U {}; + | ^ +help: use `..` to ignore all fields + | +LL | let P(..) = U {}; + | ^^ error: aborting due to 2 previous errors diff --git a/src/test/ui/issues/issue-72574-2.stderr b/src/test/ui/issues/issue-72574-2.stderr index 0a9c868af7af8cdc63e553c2e4520b4ba023ce46..a1e8ec1677db5feac9cc831ef18a2bf3809030af 100644 --- a/src/test/ui/issues/issue-72574-2.stderr +++ b/src/test/ui/issues/issue-72574-2.stderr @@ -26,6 +26,11 @@ LL | struct Binder(i32, i32, i32); ... LL | Binder(_a, _x @ ..) => {} | ^^^^^^^^^^^^^^^^^^^ expected 3 fields, found 2 + | +help: use `_` to explicitly ignore each field + | +LL | Binder(_a, _x @ .., _) => {} + | ^^^ error: aborting due to 3 previous errors diff --git a/src/test/ui/match/match-pattern-field-mismatch.stderr b/src/test/ui/match/match-pattern-field-mismatch.stderr index c2298d6fbbf02a34dc50bc17df8b46781a5f3669..37839482b31a2ef3aabae9fb356661db531c0241 100644 --- a/src/test/ui/match/match-pattern-field-mismatch.stderr +++ b/src/test/ui/match/match-pattern-field-mismatch.stderr @@ -6,6 +6,15 @@ LL | Rgb(usize, usize, usize), ... LL | Color::Rgb(_, _) => { } | ^^^^^^^^^^^^^^^^ expected 3 fields, found 2 + | +help: use `_` to explicitly ignore each field + | +LL | Color::Rgb(_, _, _) => { } + | ^^^ +help: use `..` to ignore all fields + | +LL | Color::Rgb(..) => { } + | ^^ error: aborting due to previous error diff --git a/src/test/ui/pattern/issue-74539.stderr b/src/test/ui/pattern/issue-74539.stderr index cbc90b5397d8b058f3fdc4abcf9a25fcd663f84f..f7644c19ea0d9cbc3435ef5a65f2beccb0bb2038 100644 --- a/src/test/ui/pattern/issue-74539.stderr +++ b/src/test/ui/pattern/issue-74539.stderr @@ -26,6 +26,11 @@ LL | A(u8, u8), ... LL | E::A(x @ ..) => { | ^^^^^^^^^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | E::A(x @ .., _) => { + | ^^^ error: aborting due to 3 previous errors diff --git a/src/test/ui/pattern/pat-tuple-underfield.rs b/src/test/ui/pattern/pat-tuple-underfield.rs new file mode 100644 index 0000000000000000000000000000000000000000..ed852a47bb4ee1752ea520fe2c24be41c796b7a8 --- /dev/null +++ b/src/test/ui/pattern/pat-tuple-underfield.rs @@ -0,0 +1,55 @@ +struct S(i32, f32); +enum E { + S(i32, f32), +} +struct Point4(i32, i32, i32, i32); + +fn main() { + match S(0, 1.0) { + S(x) => {} + //~^ ERROR this pattern has 1 field, but the corresponding tuple struct has 2 fields + //~| HELP use `_` to explicitly ignore each field + } + match S(0, 1.0) { + S(_) => {} + //~^ ERROR this pattern has 1 field, but the corresponding tuple struct has 2 fields + //~| HELP use `_` to explicitly ignore each field + //~| HELP use `..` to ignore all fields + } + match S(0, 1.0) { + S() => {} + //~^ ERROR this pattern has 0 fields, but the corresponding tuple struct has 2 fields + //~| HELP use `_` to explicitly ignore each field + //~| HELP use `..` to ignore all fields + } + + match E::S(0, 1.0) { + E::S(x) => {} + //~^ ERROR this pattern has 1 field, but the corresponding tuple variant has 2 fields + //~| HELP use `_` to explicitly ignore each field + } + match E::S(0, 1.0) { + E::S(_) => {} + //~^ ERROR this pattern has 1 field, but the corresponding tuple variant has 2 fields + //~| HELP use `_` to explicitly ignore each field + //~| HELP use `..` to ignore all fields + } + match E::S(0, 1.0) { + E::S() => {} + //~^ ERROR this pattern has 0 fields, but the corresponding tuple variant has 2 fields + //~| HELP use `_` to explicitly ignore each field + //~| HELP use `..` to ignore all fields + } + match E::S(0, 1.0) { + E::S => {} + //~^ ERROR expected unit struct, unit variant or constant, found tuple variant `E::S` + //~| HELP use the tuple variant pattern syntax instead + } + + match Point4(0, 1, 2, 3) { + Point4( a , _ ) => {} + //~^ ERROR this pattern has 2 fields, but the corresponding tuple struct has 4 fields + //~| HELP use `_` to explicitly ignore each field + //~| HELP use `..` to ignore the rest of the fields + } +} diff --git a/src/test/ui/pattern/pat-tuple-underfield.stderr b/src/test/ui/pattern/pat-tuple-underfield.stderr new file mode 100644 index 0000000000000000000000000000000000000000..76323d9a7bf56cba5ce792cbb2929dec11830858 --- /dev/null +++ b/src/test/ui/pattern/pat-tuple-underfield.stderr @@ -0,0 +1,131 @@ +error[E0532]: expected unit struct, unit variant or constant, found tuple variant `E::S` + --> $DIR/pat-tuple-underfield.rs:44:9 + | +LL | S(i32, f32), + | ----------- `E::S` defined here +... +LL | E::S => {} + | ^^^^ help: use the tuple variant pattern syntax instead: `E::S(_, _)` + +error[E0023]: this pattern has 1 field, but the corresponding tuple struct has 2 fields + --> $DIR/pat-tuple-underfield.rs:9:9 + | +LL | struct S(i32, f32); + | ------------------- tuple struct defined here +... +LL | S(x) => {} + | ^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | S(x, _) => {} + | ^^^ + +error[E0023]: this pattern has 1 field, but the corresponding tuple struct has 2 fields + --> $DIR/pat-tuple-underfield.rs:14:9 + | +LL | struct S(i32, f32); + | ------------------- tuple struct defined here +... +LL | S(_) => {} + | ^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | S(_, _) => {} + | ^^^ +help: use `..` to ignore all fields + | +LL | S(..) => {} + | ^^ + +error[E0023]: this pattern has 0 fields, but the corresponding tuple struct has 2 fields + --> $DIR/pat-tuple-underfield.rs:20:9 + | +LL | struct S(i32, f32); + | ------------------- tuple struct defined here +... +LL | S() => {} + | ^^^ expected 2 fields, found 0 + | +help: use `_` to explicitly ignore each field + | +LL | S(_, _) => {} + | ^^^^ +help: use `..` to ignore all fields + | +LL | S(..) => {} + | ^^ + +error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields + --> $DIR/pat-tuple-underfield.rs:27:9 + | +LL | S(i32, f32), + | ----------- tuple variant defined here +... +LL | E::S(x) => {} + | ^^^^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | E::S(x, _) => {} + | ^^^ + +error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields + --> $DIR/pat-tuple-underfield.rs:32:9 + | +LL | S(i32, f32), + | ----------- tuple variant defined here +... +LL | E::S(_) => {} + | ^^^^^^^ expected 2 fields, found 1 + | +help: use `_` to explicitly ignore each field + | +LL | E::S(_, _) => {} + | ^^^ +help: use `..` to ignore all fields + | +LL | E::S(..) => {} + | ^^ + +error[E0023]: this pattern has 0 fields, but the corresponding tuple variant has 2 fields + --> $DIR/pat-tuple-underfield.rs:38:9 + | +LL | S(i32, f32), + | ----------- tuple variant defined here +... +LL | E::S() => {} + | ^^^^^^ expected 2 fields, found 0 + | +help: use `_` to explicitly ignore each field + | +LL | E::S(_, _) => {} + | ^^^^ +help: use `..` to ignore all fields + | +LL | E::S(..) => {} + | ^^ + +error[E0023]: this pattern has 2 fields, but the corresponding tuple struct has 4 fields + --> $DIR/pat-tuple-underfield.rs:50:9 + | +LL | struct Point4(i32, i32, i32, i32); + | ---------------------------------- tuple struct defined here +... +LL | Point4( a , _ ) => {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 4 fields, found 2 + | +help: use `_` to explicitly ignore each field + | +LL | Point4( a , _ , _, _) => {} + | ^^^^^^ +help: use `..` to ignore the rest of the fields + | +LL | Point4( a , _ , ..) => {} + | ^^^^ + +error: aborting due to 8 previous errors + +Some errors have detailed explanations: E0023, E0532. +For more information about an error, try `rustc --explain E0023`.