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authorFlorian Diebold <[email protected]>2021-06-03 22:12:35 +0100
committerFlorian Diebold <[email protected]>2021-06-12 22:04:43 +0100
commit20487a1b4a7c2fdffdb1de61c7837ee6f673f21a (patch)
treeda558f908e41a890ed99f0166d23d1c2078e0053 /crates
parent124123a53bfbd32be5d63315885d2d5c9e3a1ee6 (diff)
Fix coercion in match with expected type
Plus add infrastructure to test type mismatches without expect.
Diffstat (limited to 'crates')
-rw-r--r--crates/base_db/src/lib.rs2
-rw-r--r--crates/hir_ty/src/infer.rs32
-rw-r--r--crates/hir_ty/src/infer/expr.rs7
-rw-r--r--crates/hir_ty/src/tests.rs98
-rw-r--r--crates/hir_ty/src/tests/coercion.rs43
-rw-r--r--crates/hir_ty/src/tests/patterns.rs57
6 files changed, 184 insertions, 55 deletions
diff --git a/crates/base_db/src/lib.rs b/crates/base_db/src/lib.rs
index 54baa3a63..d26f8f180 100644
--- a/crates/base_db/src/lib.rs
+++ b/crates/base_db/src/lib.rs
@@ -42,7 +42,7 @@ pub struct FilePosition {
42 pub offset: TextSize, 42 pub offset: TextSize,
43} 43}
44 44
45#[derive(Clone, Copy, Debug, Eq, PartialEq)] 45#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
46pub struct FileRange { 46pub struct FileRange {
47 pub file_id: FileId, 47 pub file_id: FileId,
48 pub range: TextRange, 48 pub range: TextRange,
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index 2c667da25..f023c1fb7 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -761,6 +761,38 @@ impl Expectation {
761 Expectation::RValueLikeUnsized(_) | Expectation::None => None, 761 Expectation::RValueLikeUnsized(_) | Expectation::None => None,
762 } 762 }
763 } 763 }
764
765 /// Comment copied from rustc:
766 /// Disregard "castable to" expectations because they
767 /// can lead us astray. Consider for example `if cond
768 /// {22} else {c} as u8` -- if we propagate the
769 /// "castable to u8" constraint to 22, it will pick the
770 /// type 22u8, which is overly constrained (c might not
771 /// be a u8). In effect, the problem is that the
772 /// "castable to" expectation is not the tightest thing
773 /// we can say, so we want to drop it in this case.
774 /// The tightest thing we can say is "must unify with
775 /// else branch". Note that in the case of a "has type"
776 /// constraint, this limitation does not hold.
777 ///
778 /// If the expected type is just a type variable, then don't use
779 /// an expected type. Otherwise, we might write parts of the type
780 /// when checking the 'then' block which are incompatible with the
781 /// 'else' branch.
782 fn adjust_for_branches(&self, table: &mut unify::InferenceTable) -> Expectation {
783 match self {
784 Expectation::HasType(ety) => {
785 let ety = table.resolve_ty_shallow(&ety);
786 if !ety.is_ty_var() {
787 Expectation::HasType(ety)
788 } else {
789 Expectation::None
790 }
791 }
792 Expectation::RValueLikeUnsized(ety) => Expectation::RValueLikeUnsized(ety.clone()),
793 _ => Expectation::None,
794 }
795 }
764} 796}
765 797
766#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)] 798#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index f73bf43b2..e34f194ff 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -337,10 +337,15 @@ impl<'a> InferenceContext<'a> {
337 Expr::Match { expr, arms } => { 337 Expr::Match { expr, arms } => {
338 let input_ty = self.infer_expr(*expr, &Expectation::none()); 338 let input_ty = self.infer_expr(*expr, &Expectation::none());
339 339
340 let expected = expected.adjust_for_branches(&mut self.table);
341
340 let mut result_ty = if arms.is_empty() { 342 let mut result_ty = if arms.is_empty() {
341 TyKind::Never.intern(&Interner) 343 TyKind::Never.intern(&Interner)
342 } else { 344 } else {
343 self.table.new_type_var() 345 match &expected {
346 Expectation::HasType(ty) => ty.clone(),
347 _ => self.table.new_type_var(),
348 }
344 }; 349 };
345 350
346 let matchee_diverges = self.diverges; 351 let matchee_diverges = self.diverges;
diff --git a/crates/hir_ty/src/tests.rs b/crates/hir_ty/src/tests.rs
index 9d726b024..b873585c4 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -9,7 +9,7 @@ mod macros;
9mod display_source_code; 9mod display_source_code;
10mod incremental; 10mod incremental;
11 11
12use std::{env, sync::Arc}; 12use std::{collections::HashMap, env, sync::Arc};
13 13
14use base_db::{fixture::WithFixture, FileRange, SourceDatabase, SourceDatabaseExt}; 14use base_db::{fixture::WithFixture, FileRange, SourceDatabase, SourceDatabaseExt};
15use expect_test::Expect; 15use expect_test::Expect;
@@ -83,9 +83,105 @@ fn check_types_impl(ra_fixture: &str, display_source: bool) {
83 checked_one = true; 83 checked_one = true;
84 } 84 }
85 } 85 }
86
86 assert!(checked_one, "no `//^` annotations found"); 87 assert!(checked_one, "no `//^` annotations found");
87} 88}
88 89
90fn check_no_mismatches(ra_fixture: &str) {
91 check_mismatches_impl(ra_fixture, true)
92}
93
94#[allow(unused)]
95fn check_mismatches(ra_fixture: &str) {
96 check_mismatches_impl(ra_fixture, false)
97}
98
99fn check_mismatches_impl(ra_fixture: &str, allow_none: bool) {
100 let _tracing = setup_tracing();
101 let (db, file_id) = TestDB::with_single_file(ra_fixture);
102 let module = db.module_for_file(file_id);
103 let def_map = module.def_map(&db);
104
105 let mut defs: Vec<DefWithBodyId> = Vec::new();
106 visit_module(&db, &def_map, module.local_id, &mut |it| defs.push(it));
107 defs.sort_by_key(|def| match def {
108 DefWithBodyId::FunctionId(it) => {
109 let loc = it.lookup(&db);
110 loc.source(&db).value.syntax().text_range().start()
111 }
112 DefWithBodyId::ConstId(it) => {
113 let loc = it.lookup(&db);
114 loc.source(&db).value.syntax().text_range().start()
115 }
116 DefWithBodyId::StaticId(it) => {
117 let loc = it.lookup(&db);
118 loc.source(&db).value.syntax().text_range().start()
119 }
120 });
121 let mut mismatches = HashMap::new();
122 let mut push_mismatch = |src_ptr: InFile<SyntaxNode>, mismatch: TypeMismatch| {
123 let range = src_ptr.value.text_range();
124 if src_ptr.file_id.call_node(&db).is_some() {
125 panic!("type mismatch in macro expansion");
126 }
127 let file_range = FileRange { file_id: src_ptr.file_id.original_file(&db), range };
128 let actual = format!(
129 "expected {}, got {}",
130 mismatch.expected.display_test(&db),
131 mismatch.actual.display_test(&db)
132 );
133 mismatches.insert(file_range, actual);
134 };
135 for def in defs {
136 let (_body, body_source_map) = db.body_with_source_map(def);
137 let inference_result = db.infer(def);
138 for (pat, mismatch) in inference_result.pat_type_mismatches() {
139 let syntax_ptr = match body_source_map.pat_syntax(pat) {
140 Ok(sp) => {
141 let root = db.parse_or_expand(sp.file_id).unwrap();
142 sp.map(|ptr| {
143 ptr.either(
144 |it| it.to_node(&root).syntax().clone(),
145 |it| it.to_node(&root).syntax().clone(),
146 )
147 })
148 }
149 Err(SyntheticSyntax) => continue,
150 };
151 push_mismatch(syntax_ptr, mismatch.clone());
152 }
153 for (expr, mismatch) in inference_result.expr_type_mismatches() {
154 let node = match body_source_map.expr_syntax(expr) {
155 Ok(sp) => {
156 let root = db.parse_or_expand(sp.file_id).unwrap();
157 sp.map(|ptr| ptr.to_node(&root).syntax().clone())
158 }
159 Err(SyntheticSyntax) => continue,
160 };
161 push_mismatch(node, mismatch.clone());
162 }
163 }
164 let mut checked_one = false;
165 for (file_id, annotations) in db.extract_annotations() {
166 for (range, expected) in annotations {
167 let file_range = FileRange { file_id, range };
168 if let Some(mismatch) = mismatches.remove(&file_range) {
169 assert_eq!(mismatch, expected);
170 } else {
171 assert!(false, "Expected mismatch not encountered: {}\n", expected);
172 }
173 checked_one = true;
174 }
175 }
176 let mut buf = String::new();
177 for (range, mismatch) in mismatches {
178 format_to!(buf, "{:?}: {}\n", range.range, mismatch,);
179 }
180 assert!(buf.is_empty(), "Unexpected type mismatches:\n{}", buf);
181
182 assert!(checked_one || allow_none, "no `//^` annotations found");
183}
184
89fn type_at_range(db: &TestDB, pos: FileRange) -> Ty { 185fn type_at_range(db: &TestDB, pos: FileRange) -> Ty {
90 let file = db.parse(pos.file_id).ok().unwrap(); 186 let file = db.parse(pos.file_id).ok().unwrap();
91 let expr = algo::find_node_at_range::<ast::Expr>(file.syntax(), pos.range).unwrap(); 187 let expr = algo::find_node_at_range::<ast::Expr>(file.syntax(), pos.range).unwrap();
diff --git a/crates/hir_ty/src/tests/coercion.rs b/crates/hir_ty/src/tests/coercion.rs
index 6dac7e103..71047703d 100644
--- a/crates/hir_ty/src/tests/coercion.rs
+++ b/crates/hir_ty/src/tests/coercion.rs
@@ -1,6 +1,6 @@
1use expect_test::expect; 1use expect_test::expect;
2 2
3use super::{check_infer, check_infer_with_mismatches, check_types}; 3use super::{check_infer, check_infer_with_mismatches, check_no_mismatches, check_types};
4 4
5#[test] 5#[test]
6fn infer_block_expr_type_mismatch() { 6fn infer_block_expr_type_mismatch() {
@@ -963,7 +963,7 @@ fn test() -> i32 {
963 963
964#[test] 964#[test]
965fn panic_macro() { 965fn panic_macro() {
966 check_infer_with_mismatches( 966 check_no_mismatches(
967 r#" 967 r#"
968mod panic { 968mod panic {
969 #[macro_export] 969 #[macro_export]
@@ -991,15 +991,34 @@ fn main() {
991 panic!() 991 panic!()
992} 992}
993 "#, 993 "#,
994 expect![[r#" 994 );
995 174..185 '{ loop {} }': ! 995}
996 176..183 'loop {}': ! 996
997 181..183 '{}': () 997#[test]
998 !0..24 '$crate...:panic': fn panic() -> ! 998fn coerce_unsize_expected_type() {
999 !0..26 '$crate...anic()': ! 999 check_no_mismatches(
1000 !0..26 '$crate...anic()': ! 1000 r#"
1001 !0..28 '$crate...015!()': ! 1001#[lang = "sized"]
1002 454..470 '{ ...c!() }': () 1002pub trait Sized {}
1003 "#]], 1003#[lang = "unsize"]
1004pub trait Unsize<T> {}
1005#[lang = "coerce_unsized"]
1006pub trait CoerceUnsized<T> {}
1007
1008impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
1009
1010fn main() {
1011 let foo: &[u32] = &[1, 2];
1012 let foo: &[u32] = match true {
1013 true => &[1, 2],
1014 false => &[1, 2, 3],
1015 };
1016 let foo: &[u32] = if true {
1017 &[1, 2]
1018 } else {
1019 &[1, 2, 3]
1020 };
1021}
1022 "#,
1004 ); 1023 );
1005} 1024}
diff --git a/crates/hir_ty/src/tests/patterns.rs b/crates/hir_ty/src/tests/patterns.rs
index 7d00cee9b..aa513c56d 100644
--- a/crates/hir_ty/src/tests/patterns.rs
+++ b/crates/hir_ty/src/tests/patterns.rs
@@ -1,6 +1,6 @@
1use expect_test::expect; 1use expect_test::expect;
2 2
3use super::{check_infer, check_infer_with_mismatches, check_types}; 3use super::{check_infer, check_infer_with_mismatches, check_mismatches, check_types};
4 4
5#[test] 5#[test]
6fn infer_pattern() { 6fn infer_pattern() {
@@ -518,47 +518,24 @@ fn infer_generics_in_patterns() {
518 518
519#[test] 519#[test]
520fn infer_const_pattern() { 520fn infer_const_pattern() {
521 check_infer_with_mismatches( 521 check_mismatches(
522 r#" 522 r#"
523 enum Option<T> { None } 523enum Option<T> { None }
524 use Option::None; 524use Option::None;
525 struct Foo; 525struct Foo;
526 const Bar: usize = 1; 526const Bar: usize = 1;
527 527
528 fn test() { 528fn test() {
529 let a: Option<u32> = None; 529 let a: Option<u32> = None;
530 let b: Option<i64> = match a { 530 let b: Option<i64> = match a {
531 None => None, 531 None => None,
532 }; 532 };
533 let _: () = match () { Foo => Foo }; // Expected mismatch 533 let _: () = match () { Foo => () };
534 let _: () = match () { Bar => Bar }; // Expected mismatch 534 // ^^^ expected (), got Foo
535 } 535 let _: () = match () { Bar => () };
536 // ^^^ expected (), got usize
537}
536 "#, 538 "#,
537 expect![[r#"
538 73..74 '1': usize
539 87..309 '{ ...atch }': ()
540 97..98 'a': Option<u32>
541 114..118 'None': Option<u32>
542 128..129 'b': Option<i64>
543 145..182 'match ... }': Option<i64>
544 151..152 'a': Option<u32>
545 163..167 'None': Option<u32>
546 171..175 'None': Option<i64>
547 192..193 '_': ()
548 200..223 'match ... Foo }': Foo
549 206..208 '()': ()
550 211..214 'Foo': Foo
551 218..221 'Foo': Foo
552 254..255 '_': ()
553 262..285 'match ... Bar }': usize
554 268..270 '()': ()
555 273..276 'Bar': usize
556 280..283 'Bar': usize
557 200..223: expected (), got Foo
558 211..214: expected (), got Foo
559 262..285: expected (), got usize
560 273..276: expected (), got usize
561 "#]],
562 ); 539 );
563} 540}
564 541