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Make empty match lint more consistent under exhaustive_patterns

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This commit is contained in:
Nadrieril 2019-12-02 17:10:20 +00:00
parent 1c77a049b9
commit 5628d4a7c3
7 changed files with 74 additions and 39 deletions
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16
src/librustc_mir/hair/pattern/check_match.rs
View file

@ -169,20 +169,14 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
// Then, if the match has no arms, check whether the scrutinee
// is uninhabited.
let pat_ty = self.tables.node_type(scrut.hir_id);
let module = self.tcx.hir().get_module_parent(scrut.hir_id);
let mut def_span = None;
let mut missing_variants = vec![];
if inlined_arms.is_empty() {
let scrutinee_is_visibly_uninhabited = if self.tcx.features().exhaustive_patterns {
let module = self.tcx.hir().get_module_parent(scrut.hir_id);
self.tcx.is_ty_uninhabited_from(module, pat_ty)
} else {
match pat_ty.kind {
ty::Never => true,
ty::Adt(def, _) => {
def_span = self.tcx.hir().span_if_local(def.did);
missing_variants =
def.variants.iter().map(|variant| variant.ident).collect();
def.variants.is_empty() && !cx.is_foreign_non_exhaustive_enum(pat_ty)
}
_ => false,
@ -190,6 +184,14 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
};
if !scrutinee_is_visibly_uninhabited {
// We know the type is inhabited, so this must be wrong
let (def_span, missing_variants) = match pat_ty.kind {
ty::Adt(def, _) => (
self.tcx.hir().span_if_local(def.did),
def.variants.iter().map(|variant| variant.ident).collect(),
),
_ => (None, vec![]),
};
let mut err = create_e0004(
self.tcx.sess,
scrut.span,

2
src/test/ui/pattern/usefulness/always-inhabited-union-ref.rs
View file

@ -25,7 +25,7 @@ fn match_on_uninhab() {
}
match uninhab_union() {
//~^ ERROR non-exhaustive patterns: type `Foo` is non-empty
//~^ ERROR non-exhaustive patterns: pattern `Foo` of type `Foo` is not handled
}
}

14
src/test/ui/pattern/usefulness/always-inhabited-union-ref.stderr
View file

@ -6,11 +6,19 @@ LL | match uninhab_ref() {
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `Foo` is non-empty
error[E0004]: non-exhaustive patterns: pattern `Foo` of type `Foo` is not handled
--> $DIR/always-inhabited-union-ref.rs:27:11
|
LL | match uninhab_union() {
| ^^^^^^^^^^^^^^^
LL | pub union Foo {
| - --- variant not covered
| _|
| |
LL | | foo: !,
LL | | }
| |_- `Foo` defined here
...
LL | match uninhab_union() {
| ^^^^^^^^^^^^^^^
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms

22
src/test/ui/pattern/usefulness/match-empty-exhaustive_patterns.rs
View file

@ -3,15 +3,15 @@
#![deny(unreachable_patterns)]
enum Foo {}
struct NonEmptyStruct(bool);
enum NonEmptyEnum1 {
Foo(bool),
struct NonEmptyStruct(bool); //~ `NonEmptyStruct` defined here
enum NonEmptyEnum1 { //~ `NonEmptyEnum1` defined here
Foo(bool), //~ variant not covered
}
enum NonEmptyEnum2 {
Foo(bool),
Bar,
enum NonEmptyEnum2 { //~ `NonEmptyEnum2` defined here
Foo(bool), //~ variant not covered
Bar, //~ variant not covered
}
enum NonEmptyEnum5 {
enum NonEmptyEnum5 { //~ `NonEmptyEnum5` defined here
V1, V2, V3, V4, V5,
}
@ -35,11 +35,11 @@ fn main() {
match 0u8 {}
//~^ ERROR type `u8` is non-empty
match NonEmptyStruct(true) {}
//~^ ERROR type `NonEmptyStruct` is non-empty
//~^ ERROR pattern `NonEmptyStruct` of type `NonEmptyStruct` is not handled
match NonEmptyEnum1::Foo(true) {}
//~^ ERROR type `NonEmptyEnum1` is non-empty
//~^ ERROR pattern `Foo` of type `NonEmptyEnum1` is not handled
match NonEmptyEnum2::Foo(true) {}
//~^ ERROR type `NonEmptyEnum2` is non-empty
//~^ ERROR multiple patterns of type `NonEmptyEnum2` are not handled
match NonEmptyEnum5::V1 {}
//~^ ERROR type `NonEmptyEnum5` is non-empty
//~^ ERROR multiple patterns of type `NonEmptyEnum5` are not handled
}

45
src/test/ui/pattern/usefulness/match-empty-exhaustive_patterns.stderr
View file

@ -30,35 +30,60 @@ LL | match 0u8 {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `NonEmptyStruct` is non-empty
error[E0004]: non-exhaustive patterns: pattern `NonEmptyStruct` of type `NonEmptyStruct` is not handled
--> $DIR/match-empty-exhaustive_patterns.rs:37:11
|
LL | struct NonEmptyStruct(bool);
| ----------------------------
| | |
| | variant not covered
| `NonEmptyStruct` defined here
...
LL | match NonEmptyStruct(true) {}
| ^^^^^^^^^^^^^^^^^^^^
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `NonEmptyEnum1` is non-empty
error[E0004]: non-exhaustive patterns: pattern `Foo` of type `NonEmptyEnum1` is not handled
--> $DIR/match-empty-exhaustive_patterns.rs:39:11
|
LL | match NonEmptyEnum1::Foo(true) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^
LL | / enum NonEmptyEnum1 {
LL | | Foo(bool),
| | --- variant not covered
LL | | }
| |_- `NonEmptyEnum1` defined here
...
LL | match NonEmptyEnum1::Foo(true) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `NonEmptyEnum2` is non-empty
error[E0004]: non-exhaustive patterns: multiple patterns of type `NonEmptyEnum2` are not handled
--> $DIR/match-empty-exhaustive_patterns.rs:41:11
|
LL | match NonEmptyEnum2::Foo(true) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^
LL | / enum NonEmptyEnum2 {
LL | | Foo(bool),
| | --- variant not covered
LL | | Bar,
| | --- variant not covered
LL | | }
| |_- `NonEmptyEnum2` defined here
...
LL | match NonEmptyEnum2::Foo(true) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `NonEmptyEnum5` is non-empty
error[E0004]: non-exhaustive patterns: multiple patterns of type `NonEmptyEnum5` are not handled
--> $DIR/match-empty-exhaustive_patterns.rs:43:11
|
LL | match NonEmptyEnum5::V1 {}
| ^^^^^^^^^^^^^^^^^
LL | / enum NonEmptyEnum5 {
LL | | V1, V2, V3, V4, V5,
LL | | }
| |_- `NonEmptyEnum5` defined here
...
LL | match NonEmptyEnum5::V1 {}
| ^^^^^^^^^^^^^^^^^
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms

8
src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.stderr
View file

@ -1,4 +1,4 @@
error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedEnum` is non-empty
error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedEnum` of type `uninhabited::IndirectUninhabitedEnum` is not handled
--> $DIR/indirect_match_with_exhaustive_patterns.rs:22:11
|
LL | match x {}
@ -6,7 +6,7 @@ LL | match x {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedStruct` is non-empty
error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedStruct` of type `uninhabited::IndirectUninhabitedStruct` is not handled
--> $DIR/indirect_match_with_exhaustive_patterns.rs:26:11
|
LL | match x {}
@ -14,7 +14,7 @@ LL | match x {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedTupleStruct` is non-empty
error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedTupleStruct` of type `uninhabited::IndirectUninhabitedTupleStruct` is not handled
--> $DIR/indirect_match_with_exhaustive_patterns.rs:30:11
|
LL | match x {}
@ -22,7 +22,7 @@ LL | match x {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedVariants` is non-empty
error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedVariants` of type `uninhabited::IndirectUninhabitedVariants` is not handled
--> $DIR/indirect_match_with_exhaustive_patterns.rs:36:11
|
LL | match x {}

6
src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
View file

@ -6,7 +6,7 @@ LL | match x {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedStruct` is non-empty
error[E0004]: non-exhaustive patterns: pattern `UninhabitedStruct` of type `uninhabited::UninhabitedStruct` is not handled
--> $DIR/match_with_exhaustive_patterns.rs:25:11
|
LL | match x {}
@ -14,7 +14,7 @@ LL | match x {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedTupleStruct` is non-empty
error[E0004]: non-exhaustive patterns: pattern `UninhabitedTupleStruct` of type `uninhabited::UninhabitedTupleStruct` is not handled
--> $DIR/match_with_exhaustive_patterns.rs:29:11
|
LL | match x {}
@ -22,7 +22,7 @@ LL | match x {}
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedVariants` is non-empty
error[E0004]: non-exhaustive patterns: multiple patterns of type `uninhabited::UninhabitedVariants` are not handled
--> $DIR/match_with_exhaustive_patterns.rs:33:11
|
LL | match x {}