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authorJosh Mcguigan <[email protected]>2020-04-06 23:38:20 +0100
committerJosh Mcguigan <[email protected]>2020-04-07 13:12:08 +0100
commita208de15b7846911856e6c069f7df03676c18a03 (patch)
tree9622890aebe6e35ad2e813b44dc8d6fdeff0559b /crates/ra_hir_ty/src
parentda6752d5f9a18ba58adb6a2e72d30a83532ec8a6 (diff)
PR feedback implementation
Diffstat (limited to 'crates/ra_hir_ty/src')
-rw-r--r--crates/ra_hir_ty/src/_match.rs425
1 files changed, 331 insertions, 94 deletions
diff --git a/crates/ra_hir_ty/src/_match.rs b/crates/ra_hir_ty/src/_match.rs
index 02472e0c0..f29a25505 100644
--- a/crates/ra_hir_ty/src/_match.rs
+++ b/crates/ra_hir_ty/src/_match.rs
@@ -2,7 +2,191 @@
2//! for match arms. 2//! for match arms.
3//! 3//!
4//! It is modeled on the rustc module `librustc_mir_build::hair::pattern::_match`, which 4//! It is modeled on the rustc module `librustc_mir_build::hair::pattern::_match`, which
5//! contains very detailed documentation about the algorithms used here. 5//! contains very detailed documentation about the algorithms used here. I've duplicated
6//! most of that documentation below.
7//!
8//! This file includes the logic for exhaustiveness and usefulness checking for
9//! pattern-matching. Specifically, given a list of patterns for a type, we can
10//! tell whether:
11//! (a) the patterns cover every possible constructor for the type [exhaustiveness]
12//! (b) each pattern is necessary [usefulness]
13//!
14//! The algorithm implemented here is a modified version of the one described in:
15//! http://moscova.inria.fr/~maranget/papers/warn/index.html
16//! However, to save future implementors from reading the original paper, we
17//! summarise the algorithm here to hopefully save time and be a little clearer
18//! (without being so rigorous).
19//!
20//! The core of the algorithm revolves about a "usefulness" check. In particular, we
21//! are trying to compute a predicate `U(P, p)` where `P` is a list of patterns (we refer to this as
22//! a matrix). `U(P, p)` represents whether, given an existing list of patterns
23//! `P_1 ..= P_m`, adding a new pattern `p` will be "useful" (that is, cover previously-
24//! uncovered values of the type).
25//!
26//! If we have this predicate, then we can easily compute both exhaustiveness of an
27//! entire set of patterns and the individual usefulness of each one.
28//! (a) the set of patterns is exhaustive iff `U(P, _)` is false (i.e., adding a wildcard
29//! match doesn't increase the number of values we're matching)
30//! (b) a pattern `P_i` is not useful if `U(P[0..=(i-1), P_i)` is false (i.e., adding a
31//! pattern to those that have come before it doesn't increase the number of values
32//! we're matching).
33//!
34//! During the course of the algorithm, the rows of the matrix won't just be individual patterns,
35//! but rather partially-deconstructed patterns in the form of a list of patterns. The paper
36//! calls those pattern-vectors, and we will call them pattern-stacks. The same holds for the
37//! new pattern `p`.
38//!
39//! For example, say we have the following:
40//! ```
41//! // x: (Option<bool>, Result<()>)
42//! match x {
43//! (Some(true), _) => {}
44//! (None, Err(())) => {}
45//! (None, Err(_)) => {}
46//! }
47//! ```
48//! Here, the matrix `P` starts as:
49//! [
50//! [(Some(true), _)],
51//! [(None, Err(()))],
52//! [(None, Err(_))],
53//! ]
54//! We can tell it's not exhaustive, because `U(P, _)` is true (we're not covering
55//! `[(Some(false), _)]`, for instance). In addition, row 3 is not useful, because
56//! all the values it covers are already covered by row 2.
57//!
58//! A list of patterns can be thought of as a stack, because we are mainly interested in the top of
59//! the stack at any given point, and we can pop or apply constructors to get new pattern-stacks.
60//! To match the paper, the top of the stack is at the beginning / on the left.
61//!
62//! There are two important operations on pattern-stacks necessary to understand the algorithm:
63//! 1. We can pop a given constructor off the top of a stack. This operation is called
64//! `specialize`, and is denoted `S(c, p)` where `c` is a constructor (like `Some` or
65//! `None`) and `p` a pattern-stack.
66//! If the pattern on top of the stack can cover `c`, this removes the constructor and
67//! pushes its arguments onto the stack. It also expands OR-patterns into distinct patterns.
68//! Otherwise the pattern-stack is discarded.
69//! This essentially filters those pattern-stacks whose top covers the constructor `c` and
70//! discards the others.
71//!
72//! For example, the first pattern above initially gives a stack `[(Some(true), _)]`. If we
73//! pop the tuple constructor, we are left with `[Some(true), _]`, and if we then pop the
74//! `Some` constructor we get `[true, _]`. If we had popped `None` instead, we would get
75//! nothing back.
76//!
77//! This returns zero or more new pattern-stacks, as follows. We look at the pattern `p_1`
78//! on top of the stack, and we have four cases:
79//! 1.1. `p_1 = c(r_1, .., r_a)`, i.e. the top of the stack has constructor `c`. We
80//! push onto the stack the arguments of this constructor, and return the result:
81//! r_1, .., r_a, p_2, .., p_n
82//! 1.2. `p_1 = c'(r_1, .., r_a')` where `c ≠ c'`. We discard the current stack and
83//! return nothing.
84//! 1.3. `p_1 = _`. We push onto the stack as many wildcards as the constructor `c` has
85//! arguments (its arity), and return the resulting stack:
86//! _, .., _, p_2, .., p_n
87//! 1.4. `p_1 = r_1 | r_2`. We expand the OR-pattern and then recurse on each resulting
88//! stack:
89//! S(c, (r_1, p_2, .., p_n))
90//! S(c, (r_2, p_2, .., p_n))
91//!
92//! 2. We can pop a wildcard off the top of the stack. This is called `D(p)`, where `p` is
93//! a pattern-stack.
94//! This is used when we know there are missing constructor cases, but there might be
95//! existing wildcard patterns, so to check the usefulness of the matrix, we have to check
96//! all its *other* components.
97//!
98//! It is computed as follows. We look at the pattern `p_1` on top of the stack,
99//! and we have three cases:
100//! 1.1. `p_1 = c(r_1, .., r_a)`. We discard the current stack and return nothing.
101//! 1.2. `p_1 = _`. We return the rest of the stack:
102//! p_2, .., p_n
103//! 1.3. `p_1 = r_1 | r_2`. We expand the OR-pattern and then recurse on each resulting
104//! stack.
105//! D((r_1, p_2, .., p_n))
106//! D((r_2, p_2, .., p_n))
107//!
108//! Note that the OR-patterns are not always used directly in Rust, but are used to derive the
109//! exhaustive integer matching rules, so they're written here for posterity.
110//!
111//! Both those operations extend straightforwardly to a list or pattern-stacks, i.e. a matrix, by
112//! working row-by-row. Popping a constructor ends up keeping only the matrix rows that start with
113//! the given constructor, and popping a wildcard keeps those rows that start with a wildcard.
114//!
115//!
116//! The algorithm for computing `U`
117//! -------------------------------
118//! The algorithm is inductive (on the number of columns: i.e., components of tuple patterns).
119//! That means we're going to check the components from left-to-right, so the algorithm
120//! operates principally on the first component of the matrix and new pattern-stack `p`.
121//! This algorithm is realised in the `is_useful` function.
122//!
123//! Base case. (`n = 0`, i.e., an empty tuple pattern)
124//! - If `P` already contains an empty pattern (i.e., if the number of patterns `m > 0`),
125//! then `U(P, p)` is false.
126//! - Otherwise, `P` must be empty, so `U(P, p)` is true.
127//!
128//! Inductive step. (`n > 0`, i.e., whether there's at least one column
129//! [which may then be expanded into further columns later])
130//! We're going to match on the top of the new pattern-stack, `p_1`.
131//! - If `p_1 == c(r_1, .., r_a)`, i.e. we have a constructor pattern.
132//! Then, the usefulness of `p_1` can be reduced to whether it is useful when
133//! we ignore all the patterns in the first column of `P` that involve other constructors.
134//! This is where `S(c, P)` comes in:
135//! `U(P, p) := U(S(c, P), S(c, p))`
136//! This special case is handled in `is_useful_specialized`.
137//!
138//! For example, if `P` is:
139//! [
140//! [Some(true), _],
141//! [None, 0],
142//! ]
143//! and `p` is [Some(false), 0], then we don't care about row 2 since we know `p` only
144//! matches values that row 2 doesn't. For row 1 however, we need to dig into the
145//! arguments of `Some` to know whether some new value is covered. So we compute
146//! `U([[true, _]], [false, 0])`.
147//!
148//! - If `p_1 == _`, then we look at the list of constructors that appear in the first
149//! component of the rows of `P`:
150//! + If there are some constructors that aren't present, then we might think that the
151//! wildcard `_` is useful, since it covers those constructors that weren't covered
152//! before.
153//! That's almost correct, but only works if there were no wildcards in those first
154//! components. So we need to check that `p` is useful with respect to the rows that
155//! start with a wildcard, if there are any. This is where `D` comes in:
156//! `U(P, p) := U(D(P), D(p))`
157//!
158//! For example, if `P` is:
159//! [
160//! [_, true, _],
161//! [None, false, 1],
162//! ]
163//! and `p` is [_, false, _], the `Some` constructor doesn't appear in `P`. So if we
164//! only had row 2, we'd know that `p` is useful. However row 1 starts with a
165//! wildcard, so we need to check whether `U([[true, _]], [false, 1])`.
166//!
167//! + Otherwise, all possible constructors (for the relevant type) are present. In this
168//! case we must check whether the wildcard pattern covers any unmatched value. For
169//! that, we can think of the `_` pattern as a big OR-pattern that covers all
170//! possible constructors. For `Option`, that would mean `_ = None | Some(_)` for
171//! example. The wildcard pattern is useful in this case if it is useful when
172//! specialized to one of the possible constructors. So we compute:
173//! `U(P, p) := ∃(k ϵ constructors) U(S(k, P), S(k, p))`
174//!
175//! For example, if `P` is:
176//! [
177//! [Some(true), _],
178//! [None, false],
179//! ]
180//! and `p` is [_, false], both `None` and `Some` constructors appear in the first
181//! components of `P`. We will therefore try popping both constructors in turn: we
182//! compute U([[true, _]], [_, false]) for the `Some` constructor, and U([[false]],
183//! [false]) for the `None` constructor. The first case returns true, so we know that
184//! `p` is useful for `P`. Indeed, it matches `[Some(false), _]` that wasn't matched
185//! before.
186//!
187//! - If `p_1 == r_1 | r_2`, then the usefulness depends on each `r_i` separately:
188//! `U(P, p) := U(P, (r_1, p_2, .., p_n))
189//! || U(P, (r_2, p_2, .., p_n))`
6use std::sync::Arc; 190use std::sync::Arc;
7 191
8use smallvec::{smallvec, SmallVec}; 192use smallvec::{smallvec, SmallVec};
@@ -134,16 +318,26 @@ impl PatStack {
134 ) -> MatchCheckResult<Option<PatStack>> { 318 ) -> MatchCheckResult<Option<PatStack>> {
135 let result = match (self.head().as_pat(cx), constructor) { 319 let result = match (self.head().as_pat(cx), constructor) {
136 (Pat::Tuple(ref pat_ids), Constructor::Tuple { arity }) => { 320 (Pat::Tuple(ref pat_ids), Constructor::Tuple { arity }) => {
137 if pat_ids.len() != *arity { 321 debug_assert_eq!(
138 None 322 pat_ids.len(),
139 } else { 323 *arity,
140 Some(self.replace_head_with(pat_ids)) 324 "we type check before calling this code, so we should never hit this case",
325 );
326
327 Some(self.replace_head_with(pat_ids))
328 }
329 (Pat::Lit(lit_expr), Constructor::Bool(constructor_val)) => {
330 match cx.body.exprs[lit_expr] {
331 Expr::Literal(Literal::Bool(pat_val)) if *constructor_val == pat_val => {
332 Some(self.to_tail())
333 }
334 // it was a bool but the value doesn't match
335 Expr::Literal(Literal::Bool(_)) => None,
336 // perhaps this is actually unreachable given we have
337 // already checked that these match arms have the appropriate type?
338 _ => return Err(MatchCheckNotImplemented),
141 } 339 }
142 } 340 }
143 (Pat::Lit(_), Constructor::Bool(_)) => {
144 // for now we only support bool literals
145 Some(self.to_tail())
146 }
147 (Pat::Wild, constructor) => Some(self.expand_wildcard(cx, constructor)?), 341 (Pat::Wild, constructor) => Some(self.expand_wildcard(cx, constructor)?),
148 (Pat::Path(_), Constructor::Enum(constructor)) => { 342 (Pat::Path(_), Constructor::Enum(constructor)) => {
149 // enums with no associated data become `Pat::Path` 343 // enums with no associated data become `Pat::Path`
@@ -162,7 +356,7 @@ impl PatStack {
162 Some(self.replace_head_with(pat_ids)) 356 Some(self.replace_head_with(pat_ids))
163 } 357 }
164 } 358 }
165 (Pat::Or(_), _) => unreachable!("we desugar or patterns so this should never happen"), 359 (Pat::Or(_), _) => return Err(MatchCheckNotImplemented),
166 (_, _) => return Err(MatchCheckNotImplemented), 360 (_, _) => return Err(MatchCheckNotImplemented),
167 }; 361 };
168 362
@@ -186,19 +380,8 @@ impl PatStack {
186 ); 380 );
187 381
188 let mut patterns: PatStackInner = smallvec![]; 382 let mut patterns: PatStackInner = smallvec![];
189 let arity = match constructor {
190 Constructor::Bool(_) => 0,
191 Constructor::Tuple { arity } => *arity,
192 Constructor::Enum(e) => {
193 match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
194 VariantData::Tuple(struct_field_data) => struct_field_data.len(),
195 VariantData::Unit => 0,
196 _ => return Err(MatchCheckNotImplemented),
197 }
198 }
199 };
200 383
201 for _ in 0..arity { 384 for _ in 0..constructor.arity(cx)? {
202 patterns.push(PatIdOrWild::Wild); 385 patterns.push(PatIdOrWild::Wild);
203 } 386 }
204 387
@@ -368,46 +551,23 @@ pub(crate) fn is_useful(
368 // constructors are covered (`Some`/`None`), so we need 551 // constructors are covered (`Some`/`None`), so we need
369 // to perform specialization to see that our wildcard will cover 552 // to perform specialization to see that our wildcard will cover
370 // the `Some(false)` case. 553 // the `Some(false)` case.
371 let mut constructor = None; 554 //
372 for pat in matrix.heads() { 555 // Here we create a constructor for each variant and then check
373 if let Some(c) = pat_constructor(cx, pat)? { 556 // usefulness after specializing for that constructor.
374 constructor = Some(c); 557 let mut found_unimplemented = false;
375 break; 558 for constructor in constructor.all_constructors(cx) {
376 } 559 let matrix = matrix.specialize_constructor(&cx, &constructor)?;
560 let v = v.expand_wildcard(&cx, &constructor)?;
561
562 match is_useful(&cx, &matrix, &v) {
563 Ok(Usefulness::Useful) => return Ok(Usefulness::Useful),
564 Ok(Usefulness::NotUseful) => continue,
565 _ => found_unimplemented = true,
566 };
377 } 567 }
378 568
379 if let Some(constructor) = constructor { 569 if found_unimplemented {
380 if let Constructor::Enum(e) = constructor { 570 Err(MatchCheckNotImplemented)
381 // For enums we handle each variant as a distinct constructor, so
382 // here we create a constructor for each variant and then check
383 // usefulness after specializing for that constructor.
384 let mut found_unimplemented = false;
385 for constructor in
386 cx.db.enum_data(e.parent).variants.iter().map(|(local_id, _)| {
387 Constructor::Enum(EnumVariantId { parent: e.parent, local_id })
388 })
389 {
390 let matrix = matrix.specialize_constructor(&cx, &constructor)?;
391 let v = v.expand_wildcard(&cx, &constructor)?;
392
393 match is_useful(&cx, &matrix, &v) {
394 Ok(Usefulness::Useful) => return Ok(Usefulness::Useful),
395 Ok(Usefulness::NotUseful) => continue,
396 _ => found_unimplemented = true,
397 };
398 }
399
400 if found_unimplemented {
401 Err(MatchCheckNotImplemented)
402 } else {
403 Ok(Usefulness::NotUseful)
404 }
405 } else {
406 let matrix = matrix.specialize_constructor(&cx, &constructor)?;
407 let v = v.expand_wildcard(&cx, &constructor)?;
408
409 is_useful(&cx, &matrix, &v)
410 }
411 } else { 571 } else {
412 Ok(Usefulness::NotUseful) 572 Ok(Usefulness::NotUseful)
413 } 573 }
@@ -425,7 +585,7 @@ pub(crate) fn is_useful(
425 } 585 }
426} 586}
427 587
428#[derive(Debug)] 588#[derive(Debug, Clone, Copy)]
429/// Similar to TypeCtor, but includes additional information about the specific 589/// Similar to TypeCtor, but includes additional information about the specific
430/// value being instantiated. For example, TypeCtor::Bool doesn't contain the 590/// value being instantiated. For example, TypeCtor::Bool doesn't contain the
431/// boolean value. 591/// boolean value.
@@ -435,6 +595,40 @@ enum Constructor {
435 Enum(EnumVariantId), 595 Enum(EnumVariantId),
436} 596}
437 597
598impl Constructor {
599 fn arity(&self, cx: &MatchCheckCtx) -> MatchCheckResult<usize> {
600 let arity = match self {
601 Constructor::Bool(_) => 0,
602 Constructor::Tuple { arity } => *arity,
603 Constructor::Enum(e) => {
604 match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
605 VariantData::Tuple(struct_field_data) => struct_field_data.len(),
606 VariantData::Unit => 0,
607 _ => return Err(MatchCheckNotImplemented),
608 }
609 }
610 };
611
612 Ok(arity)
613 }
614
615 fn all_constructors(&self, cx: &MatchCheckCtx) -> Vec<Constructor> {
616 match self {
617 Constructor::Bool(_) => vec![Constructor::Bool(true), Constructor::Bool(false)],
618 Constructor::Tuple { .. } => vec![*self],
619 Constructor::Enum(e) => cx
620 .db
621 .enum_data(e.parent)
622 .variants
623 .iter()
624 .map(|(local_id, _)| {
625 Constructor::Enum(EnumVariantId { parent: e.parent, local_id })
626 })
627 .collect(),
628 }
629 }
630}
631
438/// Returns the constructor for the given pattern. Should only return None 632/// Returns the constructor for the given pattern. Should only return None
439/// in the case of a Wild pattern. 633/// in the case of a Wild pattern.
440fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Option<Constructor>> { 634fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Option<Constructor>> {
@@ -501,14 +695,7 @@ fn all_constructors_covered(
501} 695}
502 696
503fn enum_variant_matches(cx: &MatchCheckCtx, pat_id: PatId, enum_variant_id: EnumVariantId) -> bool { 697fn enum_variant_matches(cx: &MatchCheckCtx, pat_id: PatId, enum_variant_id: EnumVariantId) -> bool {
504 if let Some(VariantId::EnumVariantId(pat_variant_id)) = 698 Some(enum_variant_id.into()) == cx.infer.variant_resolution_for_pat(pat_id)
505 cx.infer.variant_resolution_for_pat(pat_id)
506 {
507 if pat_variant_id.local_id == enum_variant_id.local_id {
508 return true;
509 }
510 }
511 false
512} 699}
513 700
514#[cfg(test)] 701#[cfg(test)]
@@ -522,10 +709,10 @@ mod tests {
522 TestDB::with_single_file(content).0.diagnostics().0 709 TestDB::with_single_file(content).0.diagnostics().0
523 } 710 }
524 711
525 pub(super) fn check_diagnostic_with_no_fix(content: &str) { 712 pub(super) fn check_diagnostic(content: &str) {
526 let diagnostic_count = TestDB::with_single_file(content).0.diagnostics().1; 713 let diagnostic_count = TestDB::with_single_file(content).0.diagnostics().1;
527 714
528 assert_eq!(1, diagnostic_count, "no diagnotic reported"); 715 assert_eq!(1, diagnostic_count, "no diagnostic reported");
529 } 716 }
530 717
531 pub(super) fn check_no_diagnostic(content: &str) { 718 pub(super) fn check_no_diagnostic(content: &str) {
@@ -558,7 +745,7 @@ mod tests {
558 } 745 }
559 "; 746 ";
560 747
561 check_diagnostic_with_no_fix(content); 748 check_diagnostic(content);
562 } 749 }
563 750
564 #[test] 751 #[test]
@@ -596,7 +783,7 @@ mod tests {
596 } 783 }
597 "; 784 ";
598 785
599 check_diagnostic_with_no_fix(content); 786 check_diagnostic(content);
600 } 787 }
601 788
602 #[test] 789 #[test]
@@ -621,7 +808,7 @@ mod tests {
621 } 808 }
622 "; 809 ";
623 810
624 check_diagnostic_with_no_fix(content); 811 check_diagnostic(content);
625 } 812 }
626 813
627 #[test] 814 #[test]
@@ -646,7 +833,7 @@ mod tests {
646 } 833 }
647 "; 834 ";
648 835
649 check_diagnostic_with_no_fix(content); 836 check_diagnostic(content);
650 } 837 }
651 838
652 #[test] 839 #[test]
@@ -659,7 +846,7 @@ mod tests {
659 } 846 }
660 "; 847 ";
661 848
662 check_diagnostic_with_no_fix(content); 849 check_diagnostic(content);
663 } 850 }
664 851
665 #[test] 852 #[test]
@@ -685,7 +872,7 @@ mod tests {
685 } 872 }
686 "; 873 ";
687 874
688 check_diagnostic_with_no_fix(content); 875 check_diagnostic(content);
689 } 876 }
690 877
691 #[test] 878 #[test]
@@ -698,7 +885,37 @@ mod tests {
698 } 885 }
699 "; 886 ";
700 887
701 check_diagnostic_with_no_fix(content); 888 check_diagnostic(content);
889 }
890
891 #[test]
892 fn tuple_of_bools_missing_arm() {
893 let content = r"
894 fn test_fn() {
895 match (false, true) {
896 (false, true) => {},
897 (false, false) => {},
898 (true, false) => {},
899 }
900 }
901 ";
902
903 check_diagnostic(content);
904 }
905
906 #[test]
907 fn tuple_of_bools_with_wilds() {
908 let content = r"
909 fn test_fn() {
910 match (false, true) {
911 (false, _) => {},
912 (true, false) => {},
913 (_, true) => {},
914 }
915 }
916 ";
917
918 check_no_diagnostic(content);
702 } 919 }
703 920
704 #[test] 921 #[test]
@@ -727,7 +944,7 @@ mod tests {
727 } 944 }
728 "; 945 ";
729 946
730 check_diagnostic_with_no_fix(content); 947 check_diagnostic(content);
731 } 948 }
732 949
733 #[test] 950 #[test]
@@ -754,7 +971,7 @@ mod tests {
754 } 971 }
755 "; 972 ";
756 973
757 check_diagnostic_with_no_fix(content); 974 check_diagnostic(content);
758 } 975 }
759 976
760 #[test] 977 #[test]
@@ -767,7 +984,7 @@ mod tests {
767 } 984 }
768 "; 985 ";
769 986
770 check_diagnostic_with_no_fix(content); 987 check_diagnostic(content);
771 } 988 }
772 989
773 #[test] 990 #[test]
@@ -796,7 +1013,7 @@ mod tests {
796 } 1013 }
797 "; 1014 ";
798 1015
799 check_diagnostic_with_no_fix(content); 1016 check_diagnostic(content);
800 } 1017 }
801 1018
802 #[test] 1019 #[test]
@@ -827,7 +1044,7 @@ mod tests {
827 } 1044 }
828 "; 1045 ";
829 1046
830 check_diagnostic_with_no_fix(content); 1047 check_diagnostic(content);
831 } 1048 }
832 1049
833 #[test] 1050 #[test]
@@ -844,7 +1061,7 @@ mod tests {
844 } 1061 }
845 "; 1062 ";
846 1063
847 check_diagnostic_with_no_fix(content); 1064 check_diagnostic(content);
848 } 1065 }
849 1066
850 #[test] 1067 #[test]
@@ -879,7 +1096,7 @@ mod tests {
879 } 1096 }
880 "; 1097 ";
881 1098
882 check_diagnostic_with_no_fix(content); 1099 check_diagnostic(content);
883 } 1100 }
884 1101
885 #[test] 1102 #[test]
@@ -913,7 +1130,7 @@ mod tests {
913 } 1130 }
914 "; 1131 ";
915 1132
916 check_diagnostic_with_no_fix(content); 1133 check_diagnostic(content);
917 } 1134 }
918 1135
919 #[test] 1136 #[test]
@@ -931,7 +1148,7 @@ mod tests {
931 } 1148 }
932 "; 1149 ";
933 1150
934 check_diagnostic_with_no_fix(content); 1151 check_diagnostic(content);
935 } 1152 }
936 1153
937 #[test] 1154 #[test]
@@ -1004,7 +1221,7 @@ mod tests {
1004 } 1221 }
1005 "; 1222 ";
1006 1223
1007 check_diagnostic_with_no_fix(content); 1224 check_diagnostic(content);
1008 } 1225 }
1009 1226
1010 #[test] 1227 #[test]
@@ -1089,7 +1306,7 @@ mod tests {
1089 "; 1306 ";
1090 1307
1091 // Match arms with the incorrect type are filtered out. 1308 // Match arms with the incorrect type are filtered out.
1092 check_diagnostic_with_no_fix(content); 1309 check_diagnostic(content);
1093 } 1310 }
1094 1311
1095 #[test] 1312 #[test]
@@ -1104,7 +1321,23 @@ mod tests {
1104 "; 1321 ";
1105 1322
1106 // Match arms with the incorrect type are filtered out. 1323 // Match arms with the incorrect type are filtered out.
1107 check_diagnostic_with_no_fix(content); 1324 check_diagnostic(content);
1325 }
1326
1327 #[test]
1328 fn enum_not_in_scope() {
1329 let content = r"
1330 fn test_fn() {
1331 match Foo::Bar {
1332 Foo::Baz => (),
1333 }
1334 }
1335 ";
1336
1337 // The enum is not in scope so we don't perform exhaustiveness
1338 // checking, but we want to be sure we don't panic here (and
1339 // we don't create a diagnostic).
1340 check_no_diagnostic(content);
1108 } 1341 }
1109} 1342}
1110 1343
@@ -1158,17 +1391,21 @@ mod false_negatives {
1158 } 1391 }
1159 1392
1160 #[test] 1393 #[test]
1161 fn enum_not_in_scope() { 1394 fn internal_or() {
1162 let content = r" 1395 let content = r"
1163 fn test_fn() { 1396 fn test_fn() {
1164 match Foo::Bar { 1397 enum Either {
1165 Foo::Baz => (), 1398 A(bool),
1399 B,
1400 }
1401 match Either::B {
1402 Either::A(true | false) => (),
1166 } 1403 }
1167 } 1404 }
1168 "; 1405 ";
1169 1406
1170 // This is a false negative. 1407 // This is a false negative.
1171 // The enum is not in scope so we don't perform exhaustiveness checking. 1408 // We do not currently handle patterns with internal `or`s.
1172 check_no_diagnostic(content); 1409 check_no_diagnostic(content);
1173 } 1410 }
1174} 1411}