aboutsummaryrefslogtreecommitdiff
path: root/crates/hir_ty/src/infer/coerce.rs
diff options
context:
space:
mode:
Diffstat (limited to 'crates/hir_ty/src/infer/coerce.rs')
-rw-r--r--crates/hir_ty/src/infer/coerce.rs79
1 files changed, 36 insertions, 43 deletions
diff --git a/crates/hir_ty/src/infer/coerce.rs b/crates/hir_ty/src/infer/coerce.rs
index 32c7c57cd..4cca35904 100644
--- a/crates/hir_ty/src/infer/coerce.rs
+++ b/crates/hir_ty/src/infer/coerce.rs
@@ -7,7 +7,7 @@
7use hir_def::{lang_item::LangItemTarget, type_ref::Mutability}; 7use hir_def::{lang_item::LangItemTarget, type_ref::Mutability};
8use test_utils::mark; 8use test_utils::mark;
9 9
10use crate::{autoderef, traits::Solution, Obligation, Substs, TraitRef, Ty, TypeCtor}; 10use crate::{autoderef, traits::Solution, Obligation, Substs, TraitRef, Ty};
11 11
12use super::{unify::TypeVarValue, InEnvironment, InferTy, InferenceContext}; 12use super::{unify::TypeVarValue, InEnvironment, InferTy, InferenceContext};
13 13
@@ -33,7 +33,7 @@ impl<'a> InferenceContext<'a> {
33 } else if self.coerce(ty2, ty1) { 33 } else if self.coerce(ty2, ty1) {
34 ty1.clone() 34 ty1.clone()
35 } else { 35 } else {
36 if let (ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnDef(_))) = (ty1, ty2) { 36 if let (Ty::FnDef(..), Ty::FnDef(..)) = (ty1, ty2) {
37 mark::hit!(coerce_fn_reification); 37 mark::hit!(coerce_fn_reification);
38 // Special case: two function types. Try to coerce both to 38 // Special case: two function types. Try to coerce both to
39 // pointers to have a chance at getting a match. See 39 // pointers to have a chance at getting a match. See
@@ -53,12 +53,12 @@ impl<'a> InferenceContext<'a> {
53 fn coerce_inner(&mut self, mut from_ty: Ty, to_ty: &Ty) -> bool { 53 fn coerce_inner(&mut self, mut from_ty: Ty, to_ty: &Ty) -> bool {
54 match (&from_ty, to_ty) { 54 match (&from_ty, to_ty) {
55 // Never type will make type variable to fallback to Never Type instead of Unknown. 55 // Never type will make type variable to fallback to Never Type instead of Unknown.
56 (ty_app!(TypeCtor::Never), Ty::Infer(InferTy::TypeVar(tv))) => { 56 (Ty::Never, Ty::Infer(InferTy::TypeVar(tv))) => {
57 let var = self.table.new_maybe_never_type_var(); 57 let var = self.table.new_maybe_never_type_var();
58 self.table.var_unification_table.union_value(*tv, TypeVarValue::Known(var)); 58 self.table.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
59 return true; 59 return true;
60 } 60 }
61 (ty_app!(TypeCtor::Never), _) => return true, 61 (Ty::Never, _) => return true,
62 62
63 // Trivial cases, this should go after `never` check to 63 // Trivial cases, this should go after `never` check to
64 // avoid infer result type to be never 64 // avoid infer result type to be never
@@ -71,38 +71,33 @@ impl<'a> InferenceContext<'a> {
71 71
72 // Pointer weakening and function to pointer 72 // Pointer weakening and function to pointer
73 match (&mut from_ty, to_ty) { 73 match (&mut from_ty, to_ty) {
74 // `*mut T`, `&mut T, `&T`` -> `*const T` 74 // `*mut T` -> `*const T`
75 // `&mut T` -> `&T` 75 // `&mut T` -> `&T`
76 // `&mut T` -> `*mut T` 76 (Ty::RawPtr(m1, ..), Ty::RawPtr(m2 @ Mutability::Shared, ..))
77 (ty_app!(c1@TypeCtor::RawPtr(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared))) 77 | (Ty::Ref(m1, ..), Ty::Ref(m2 @ Mutability::Shared, ..)) => {
78 | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared))) 78 *m1 = *m2;
79 | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::Ref(Mutability::Shared))) 79 }
80 | (ty_app!(c1@TypeCtor::Ref(Mutability::Mut)), ty_app!(c2@TypeCtor::RawPtr(_))) => { 80 // `&T` -> `*const T`
81 *c1 = *c2; 81 // `&mut T` -> `*mut T`/`*const T`
82 (Ty::Ref(.., substs), &Ty::RawPtr(m2 @ Mutability::Shared, ..))
83 | (Ty::Ref(Mutability::Mut, substs), &Ty::RawPtr(m2, ..)) => {
84 from_ty = Ty::RawPtr(m2, substs.clone());
82 } 85 }
83 86
84 // Illegal mutablity conversion 87 // Illegal mutability conversion
85 ( 88 (Ty::RawPtr(Mutability::Shared, ..), Ty::RawPtr(Mutability::Mut, ..))
86 ty_app!(TypeCtor::RawPtr(Mutability::Shared)), 89 | (Ty::Ref(Mutability::Shared, ..), Ty::Ref(Mutability::Mut, ..)) => return false,
87 ty_app!(TypeCtor::RawPtr(Mutability::Mut)),
88 )
89 | (
90 ty_app!(TypeCtor::Ref(Mutability::Shared)),
91 ty_app!(TypeCtor::Ref(Mutability::Mut)),
92 ) => return false,
93 90
94 // `{function_type}` -> `fn()` 91 // `{function_type}` -> `fn()`
95 (ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnPtr { .. })) => { 92 (Ty::FnDef(..), Ty::Function { .. }) => match from_ty.callable_sig(self.db) {
96 match from_ty.callable_sig(self.db) { 93 None => return false,
97 None => return false, 94 Some(sig) => {
98 Some(sig) => { 95 from_ty = Ty::fn_ptr(sig);
99 from_ty = Ty::fn_ptr(sig);
100 }
101 } 96 }
102 } 97 },
103 98
104 (ty_app!(TypeCtor::Closure { .. }, params), ty_app!(TypeCtor::FnPtr { .. })) => { 99 (Ty::Closure(.., substs), Ty::Function { .. }) => {
105 from_ty = params[0].clone(); 100 from_ty = substs[0].clone();
106 } 101 }
107 102
108 _ => {} 103 _ => {}
@@ -115,9 +110,7 @@ impl<'a> InferenceContext<'a> {
115 // Auto Deref if cannot coerce 110 // Auto Deref if cannot coerce
116 match (&from_ty, to_ty) { 111 match (&from_ty, to_ty) {
117 // FIXME: DerefMut 112 // FIXME: DerefMut
118 (ty_app!(TypeCtor::Ref(_), st1), ty_app!(TypeCtor::Ref(_), st2)) => { 113 (Ty::Ref(_, st1), Ty::Ref(_, st2)) => self.unify_autoderef_behind_ref(&st1[0], &st2[0]),
119 self.unify_autoderef_behind_ref(&st1[0], &st2[0])
120 }
121 114
122 // Otherwise, normal unify 115 // Otherwise, normal unify
123 _ => self.unify(&from_ty, to_ty), 116 _ => self.unify(&from_ty, to_ty),
@@ -178,17 +171,17 @@ impl<'a> InferenceContext<'a> {
178 }, 171 },
179 ) { 172 ) {
180 let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value); 173 let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
181 match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) { 174 let from_ty = self.resolve_ty_shallow(&derefed_ty);
182 // Stop when constructor matches. 175 // Stop when constructor matches.
183 (ty_app!(from_ctor, st1), ty_app!(to_ctor, st2)) if from_ctor == to_ctor => { 176 if from_ty.equals_ctor(&to_ty) {
184 // It will not recurse to `coerce`. 177 // It will not recurse to `coerce`.
185 return self.table.unify_substs(st1, st2, 0); 178 return match (from_ty.substs(), to_ty.substs()) {
186 } 179 (Some(st1), Some(st2)) => self.table.unify_substs(st1, st2, 0),
187 _ => { 180 (None, None) => true,
188 if self.table.unify_inner_trivial(&derefed_ty, &to_ty, 0) { 181 _ => false,
189 return true; 182 };
190 } 183 } else if self.table.unify_inner_trivial(&derefed_ty, &to_ty, 0) {
191 } 184 return true;
192 } 185 }
193 } 186 }
194 187