| 1 | // Copyright 2022 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 ssa |
| 6 | |
| 7 | import ( |
| 8 | "go/ast" |
| 9 | "go/parser" |
| 10 | "go/token" |
| 11 | "go/types" |
| 12 | "testing" |
| 13 | |
| 14 | "golang.org/x/tools/internal/typeparams" |
| 15 | ) |
| 16 | |
| 17 | func TestSubst(t *testing.T) { |
| 18 | if !typeparams.Enabled { |
| 19 | return |
| 20 | } |
| 21 | |
| 22 | const source = ` |
| 23 | package P |
| 24 | |
| 25 | type t0 int |
| 26 | func (t0) f() |
| 27 | type t1 interface{ f() } |
| 28 | type t2 interface{ g() } |
| 29 | type t3 interface{ ~int } |
| 30 | |
| 31 | func Fn0[T t1](x T) T { |
| 32 | x.f() |
| 33 | return x |
| 34 | } |
| 35 | |
| 36 | type A[T any] [4]T |
| 37 | type B[T any] []T |
| 38 | type C[T, S any] []struct{s S; t T} |
| 39 | type D[T, S any] *struct{s S; t *T} |
| 40 | type E[T, S any] interface{ F() (T, S) } |
| 41 | type F[K comparable, V any] map[K]V |
| 42 | type G[T any] chan *T |
| 43 | type H[T any] func() T |
| 44 | type I[T any] struct{x, y, z int; t T} |
| 45 | type J[T any] interface{ t1 } |
| 46 | type K[T any] interface{ t1; F() T } |
| 47 | type L[T any] interface{ F() T; J[T] } |
| 48 | |
| 49 | var _ L[int] = Fn0[L[int]](nil) |
| 50 | ` |
| 51 | |
| 52 | fset := token.NewFileSet() |
| 53 | f, err := parser.ParseFile(fset, "hello.go", source, 0) |
| 54 | if err != nil { |
| 55 | t.Fatal(err) |
| 56 | } |
| 57 | |
| 58 | var conf types.Config |
| 59 | pkg, err := conf.Check("P", fset, []*ast.File{f}, nil) |
| 60 | if err != nil { |
| 61 | t.Fatal(err) |
| 62 | } |
| 63 | |
| 64 | for _, test := range []struct { |
| 65 | expr string // type expression of Named parameterized type |
| 66 | args []string // type expressions of args for named |
| 67 | want string // expected underlying value after substitution |
| 68 | }{ |
| 69 | {"A", []string{"string"}, "[4]string"}, |
| 70 | {"A", []string{"int"}, "[4]int"}, |
| 71 | {"B", []string{"int"}, "[]int"}, |
| 72 | {"B", []string{"int8"}, "[]int8"}, |
| 73 | {"C", []string{"int8", "string"}, "[]struct{s string; t int8}"}, |
| 74 | {"C", []string{"string", "int8"}, "[]struct{s int8; t string}"}, |
| 75 | {"D", []string{"int16", "string"}, "*struct{s string; t *int16}"}, |
| 76 | {"E", []string{"int32", "string"}, "interface{F() (int32, string)}"}, |
| 77 | {"F", []string{"int64", "string"}, "map[int64]string"}, |
| 78 | {"G", []string{"uint64"}, "chan *uint64"}, |
| 79 | {"H", []string{"uintptr"}, "func() uintptr"}, |
| 80 | {"I", []string{"t0"}, "struct{x int; y int; z int; t P.t0}"}, |
| 81 | {"J", []string{"t0"}, "interface{P.t1}"}, |
| 82 | {"K", []string{"t0"}, "interface{F() P.t0; P.t1}"}, |
| 83 | {"L", []string{"t0"}, "interface{F() P.t0; P.J[P.t0]}"}, |
| 84 | {"L", []string{"L[t0]"}, "interface{F() P.L[P.t0]; P.J[P.L[P.t0]]}"}, |
| 85 | } { |
| 86 | // Eval() expr for its type. |
| 87 | tv, err := types.Eval(fset, pkg, 0, test.expr) |
| 88 | if err != nil { |
| 89 | t.Fatalf("Eval(%s) failed: %v", test.expr, err) |
| 90 | } |
| 91 | // Eval() test.args[i] to get the i'th type arg. |
| 92 | var targs []types.Type |
| 93 | for _, astr := range test.args { |
| 94 | tv, err := types.Eval(fset, pkg, 0, astr) |
| 95 | if err != nil { |
| 96 | t.Fatalf("Eval(%s) failed: %v", astr, err) |
| 97 | } |
| 98 | targs = append(targs, tv.Type) |
| 99 | } |
| 100 | |
| 101 | T := tv.Type.(*types.Named) |
| 102 | |
| 103 | subst := makeSubster(typeparams.NewContext(), typeparams.ForNamed(T), targs, true) |
| 104 | sub := subst.typ(T.Underlying()) |
| 105 | if got := sub.String(); got != test.want { |
| 106 | t.Errorf("subst{%v->%v}.typ(%s) = %v, want %v", test.expr, test.args, T.Underlying(), got, test.want) |
| 107 | } |
| 108 | } |
| 109 | } |
| 110 |
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