Dan Willemsen | bc60c3c | 2021-12-15 01:09:00 -0800 | [diff] [blame] | 1 | // Copyright 2021 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package types_test |
| 6 | |
| 7 | import ( |
| 8 | "go/token" |
| 9 | . "go/types" |
| 10 | "strings" |
| 11 | "testing" |
| 12 | ) |
| 13 | |
| 14 | func TestInstantiateEquality(t *testing.T) { |
| 15 | emptySignature := NewSignatureType(nil, nil, nil, nil, nil, false) |
| 16 | tests := []struct { |
| 17 | src string |
| 18 | name1 string |
| 19 | targs1 []Type |
| 20 | name2 string |
| 21 | targs2 []Type |
| 22 | wantEqual bool |
| 23 | }{ |
| 24 | { |
| 25 | "package basictype; type T[P any] int", |
| 26 | "T", []Type{Typ[Int]}, |
| 27 | "T", []Type{Typ[Int]}, |
| 28 | true, |
| 29 | }, |
| 30 | { |
| 31 | "package differenttypeargs; type T[P any] int", |
| 32 | "T", []Type{Typ[Int]}, |
| 33 | "T", []Type{Typ[String]}, |
| 34 | false, |
| 35 | }, |
| 36 | { |
| 37 | "package typeslice; type T[P any] int", |
| 38 | "T", []Type{NewSlice(Typ[Int])}, |
| 39 | "T", []Type{NewSlice(Typ[Int])}, |
| 40 | true, |
| 41 | }, |
| 42 | { |
| 43 | // interface{interface{...}} is equivalent to interface{...} |
| 44 | "package equivalentinterfaces; type T[P any] int", |
| 45 | "T", []Type{ |
| 46 | NewInterfaceType([]*Func{NewFunc(token.NoPos, nil, "M", emptySignature)}, nil), |
| 47 | }, |
| 48 | "T", []Type{ |
| 49 | NewInterfaceType( |
| 50 | nil, |
| 51 | []Type{ |
| 52 | NewInterfaceType([]*Func{NewFunc(token.NoPos, nil, "M", emptySignature)}, nil), |
| 53 | }, |
| 54 | ), |
| 55 | }, |
| 56 | true, |
| 57 | }, |
| 58 | { |
| 59 | // int|string is equivalent to string|int |
| 60 | "package equivalenttypesets; type T[P any] int", |
| 61 | "T", []Type{ |
| 62 | NewInterfaceType(nil, []Type{ |
| 63 | NewUnion([]*Term{NewTerm(false, Typ[Int]), NewTerm(false, Typ[String])}), |
| 64 | }), |
| 65 | }, |
| 66 | "T", []Type{ |
| 67 | NewInterfaceType(nil, []Type{ |
| 68 | NewUnion([]*Term{NewTerm(false, Typ[String]), NewTerm(false, Typ[Int])}), |
| 69 | }), |
| 70 | }, |
| 71 | true, |
| 72 | }, |
| 73 | { |
| 74 | "package basicfunc; func F[P any]() {}", |
| 75 | "F", []Type{Typ[Int]}, |
| 76 | "F", []Type{Typ[Int]}, |
| 77 | true, |
| 78 | }, |
| 79 | { |
| 80 | "package funcslice; func F[P any]() {}", |
| 81 | "F", []Type{NewSlice(Typ[Int])}, |
| 82 | "F", []Type{NewSlice(Typ[Int])}, |
| 83 | true, |
| 84 | }, |
| 85 | { |
| 86 | "package funcwithparams; func F[P any](x string) float64 { return 0 }", |
| 87 | "F", []Type{Typ[Int]}, |
| 88 | "F", []Type{Typ[Int]}, |
| 89 | true, |
| 90 | }, |
| 91 | { |
| 92 | "package differentfuncargs; func F[P any](x string) float64 { return 0 }", |
| 93 | "F", []Type{Typ[Int]}, |
| 94 | "F", []Type{Typ[String]}, |
| 95 | false, |
| 96 | }, |
| 97 | { |
| 98 | "package funcequality; func F1[P any](x int) {}; func F2[Q any](x int) {}", |
| 99 | "F1", []Type{Typ[Int]}, |
| 100 | "F2", []Type{Typ[Int]}, |
| 101 | false, |
| 102 | }, |
| 103 | { |
| 104 | "package funcsymmetry; func F1[P any](x P) {}; func F2[Q any](x Q) {}", |
| 105 | "F1", []Type{Typ[Int]}, |
| 106 | "F2", []Type{Typ[Int]}, |
| 107 | false, |
| 108 | }, |
| 109 | } |
| 110 | |
| 111 | for _, test := range tests { |
| 112 | pkg, err := pkgForMode(".", test.src, nil, 0) |
| 113 | if err != nil { |
| 114 | t.Fatal(err) |
| 115 | } |
| 116 | |
| 117 | t.Run(pkg.Name(), func(t *testing.T) { |
| 118 | ctxt := NewContext() |
| 119 | |
| 120 | T1 := pkg.Scope().Lookup(test.name1).Type() |
| 121 | res1, err := Instantiate(ctxt, T1, test.targs1, false) |
| 122 | if err != nil { |
| 123 | t.Fatal(err) |
| 124 | } |
| 125 | |
| 126 | T2 := pkg.Scope().Lookup(test.name2).Type() |
| 127 | res2, err := Instantiate(ctxt, T2, test.targs2, false) |
| 128 | if err != nil { |
| 129 | t.Fatal(err) |
| 130 | } |
| 131 | |
| 132 | if gotEqual := res1 == res2; gotEqual != test.wantEqual { |
| 133 | t.Errorf("%s == %s: %t, want %t", res1, res2, gotEqual, test.wantEqual) |
| 134 | } |
| 135 | }) |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | func TestInstantiateNonEquality(t *testing.T) { |
| 140 | const src = "package p; type T[P any] int" |
| 141 | |
| 142 | pkg1, err := pkgForMode(".", src, nil, 0) |
| 143 | if err != nil { |
| 144 | t.Fatal(err) |
| 145 | } |
| 146 | pkg2, err := pkgForMode(".", src, nil, 0) |
| 147 | if err != nil { |
| 148 | t.Fatal(err) |
| 149 | } |
| 150 | |
| 151 | // We consider T1 and T2 to be distinct types, so their instances should not |
| 152 | // be deduplicated by the context. |
| 153 | T1 := pkg1.Scope().Lookup("T").Type().(*Named) |
| 154 | T2 := pkg2.Scope().Lookup("T").Type().(*Named) |
| 155 | |
| 156 | ctxt := NewContext() |
| 157 | res1, err := Instantiate(ctxt, T1, []Type{Typ[Int]}, false) |
| 158 | if err != nil { |
| 159 | t.Fatal(err) |
| 160 | } |
| 161 | res2, err := Instantiate(ctxt, T2, []Type{Typ[Int]}, false) |
| 162 | if err != nil { |
| 163 | t.Fatal(err) |
| 164 | } |
| 165 | |
| 166 | if res1 == res2 { |
| 167 | t.Errorf("instance from pkg1 (%s) is pointer-equivalent to instance from pkg2 (%s)", res1, res2) |
| 168 | } |
| 169 | if Identical(res1, res2) { |
| 170 | t.Errorf("instance from pkg1 (%s) is identical to instance from pkg2 (%s)", res1, res2) |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | func TestMethodInstantiation(t *testing.T) { |
| 175 | const prefix = `package p |
| 176 | |
| 177 | type T[P any] struct{} |
| 178 | |
| 179 | var X T[int] |
| 180 | |
| 181 | ` |
| 182 | tests := []struct { |
| 183 | decl string |
| 184 | want string |
| 185 | }{ |
| 186 | {"func (r T[P]) m() P", "func (T[int]).m() int"}, |
| 187 | {"func (r T[P]) m(P)", "func (T[int]).m(int)"}, |
| 188 | {"func (r *T[P]) m(P)", "func (*T[int]).m(int)"}, |
| 189 | {"func (r T[P]) m() T[P]", "func (T[int]).m() T[int]"}, |
| 190 | {"func (r T[P]) m(T[P])", "func (T[int]).m(T[int])"}, |
| 191 | {"func (r T[P]) m(T[P], P, string)", "func (T[int]).m(T[int], int, string)"}, |
| 192 | {"func (r T[P]) m(T[P], T[string], T[int])", "func (T[int]).m(T[int], T[string], T[int])"}, |
| 193 | } |
| 194 | |
| 195 | for _, test := range tests { |
| 196 | src := prefix + test.decl |
| 197 | pkg, err := pkgForMode(".", src, nil, 0) |
| 198 | if err != nil { |
| 199 | t.Fatal(err) |
| 200 | } |
| 201 | typ := NewPointer(pkg.Scope().Lookup("X").Type()) |
| 202 | obj, _, _ := LookupFieldOrMethod(typ, false, pkg, "m") |
| 203 | m, _ := obj.(*Func) |
| 204 | if m == nil { |
| 205 | t.Fatalf(`LookupFieldOrMethod(%s, "m") = %v, want func m`, typ, obj) |
| 206 | } |
| 207 | if got := ObjectString(m, RelativeTo(pkg)); got != test.want { |
| 208 | t.Errorf("instantiated %q, want %q", got, test.want) |
| 209 | } |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | func TestImmutableSignatures(t *testing.T) { |
| 214 | const src = `package p |
| 215 | |
| 216 | type T[P any] struct{} |
| 217 | |
| 218 | func (T[P]) m() {} |
| 219 | |
| 220 | var _ T[int] |
| 221 | ` |
| 222 | pkg, err := pkgForMode(".", src, nil, 0) |
| 223 | if err != nil { |
| 224 | t.Fatal(err) |
| 225 | } |
| 226 | typ := pkg.Scope().Lookup("T").Type().(*Named) |
| 227 | obj, _, _ := LookupFieldOrMethod(typ, false, pkg, "m") |
| 228 | if obj == nil { |
| 229 | t.Fatalf(`LookupFieldOrMethod(%s, "m") = %v, want func m`, typ, obj) |
| 230 | } |
| 231 | |
| 232 | // Verify that the original method is not mutated by instantiating T (this |
| 233 | // bug manifested when subst did not return a new signature). |
| 234 | want := "func (T[P]).m()" |
| 235 | if got := stripAnnotations(ObjectString(obj, RelativeTo(pkg))); got != want { |
| 236 | t.Errorf("instantiated %q, want %q", got, want) |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | // Copied from errors.go. |
| 241 | func stripAnnotations(s string) string { |
| 242 | var b strings.Builder |
| 243 | for _, r := range s { |
| 244 | // strip #'s and subscript digits |
| 245 | if r < '₀' || '₀'+10 <= r { // '₀' == U+2080 |
| 246 | b.WriteRune(r) |
| 247 | } |
| 248 | } |
| 249 | if b.Len() < len(s) { |
| 250 | return b.String() |
| 251 | } |
| 252 | return s |
| 253 | } |