api_test.go raw
1 // Copyright 2013 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 "errors"
9 "fmt"
10 "go/ast"
11 "go/importer"
12 "go/parser"
13 "go/token"
14 "internal/goversion"
15 "internal/testenv"
16 "slices"
17 "sort"
18 "strings"
19 "sync"
20 "testing"
21
22 . "go/types"
23 "runtime"
24 )
25
26 // nopos indicates an unknown position
27 var nopos token.Pos
28
29 func defaultImporter(fset *token.FileSet) Importer {
30 return importer.ForCompiler(fset, runtime.Compiler, nil)
31 }
32
33 func mustParse(fset *token.FileSet, src string) *ast.File {
34 f, err := parser.ParseFile(fset, pkgName(src), src, parser.ParseComments)
35 if err != nil {
36 panic(err) // so we don't need to pass *testing.T
37 }
38 return f
39 }
40
41 func typecheck(src string, conf *Config, info *Info) (*Package, error) {
42 // TODO(adonovan): plumb this from caller.
43 fset := token.NewFileSet()
44 f := mustParse(fset, src)
45 if conf == nil {
46 conf = &Config{
47 Error: func(err error) {}, // collect all errors
48 Importer: defaultImporter(fset),
49 }
50 }
51 return conf.Check(f.Name.Name, fset, []*ast.File{f}, info)
52 }
53
54 func mustTypecheck(src string, conf *Config, info *Info) *Package {
55 pkg, err := typecheck(src, conf, info)
56 if err != nil {
57 panic(err) // so we don't need to pass *testing.T
58 }
59 return pkg
60 }
61
62 // pkgName extracts the package name from src, which must contain a package header.
63 func pkgName(src string) string {
64 const kw = "package "
65 if i := strings.Index(src, kw); i >= 0 {
66 after := src[i+len(kw):]
67 n := len(after)
68 if i := strings.IndexAny(after, "\n\t ;/"); i >= 0 {
69 n = i
70 }
71 return after[:n]
72 }
73 panic("missing package header: " + src)
74 }
75
76 func TestValuesInfo(t *testing.T) {
77 var tests = []struct {
78 src string
79 expr string // constant expression
80 typ string // constant type
81 val string // constant value
82 }{
83 {`package a0; const _ = false`, `false`, `untyped bool`, `false`},
84 {`package a1; const _ = 0`, `0`, `untyped int`, `0`},
85 {`package a2; const _ = 'A'`, `'A'`, `untyped rune`, `65`},
86 {`package a3; const _ = 0.`, `0.`, `untyped float`, `0`},
87 {`package a4; const _ = 0i`, `0i`, `untyped complex`, `(0 + 0i)`},
88 {`package a5; const _ = "foo"`, `"foo"`, `untyped string`, `"foo"`},
89
90 {`package b0; var _ = false`, `false`, `bool`, `false`},
91 {`package b1; var _ = 0`, `0`, `int`, `0`},
92 {`package b2; var _ = 'A'`, `'A'`, `rune`, `65`},
93 {`package b3; var _ = 0.`, `0.`, `float64`, `0`},
94 {`package b4; var _ = 0i`, `0i`, `complex128`, `(0 + 0i)`},
95 {`package b5; var _ = "foo"`, `"foo"`, `string`, `"foo"`},
96
97 {`package c0a; var _ = bool(false)`, `false`, `bool`, `false`},
98 {`package c0b; var _ = bool(false)`, `bool(false)`, `bool`, `false`},
99 {`package c0c; type T bool; var _ = T(false)`, `T(false)`, `c0c.T`, `false`},
100
101 {`package c1a; var _ = int(0)`, `0`, `int`, `0`},
102 {`package c1b; var _ = int(0)`, `int(0)`, `int`, `0`},
103 {`package c1c; type T int; var _ = T(0)`, `T(0)`, `c1c.T`, `0`},
104
105 {`package c2a; var _ = rune('A')`, `'A'`, `rune`, `65`},
106 {`package c2b; var _ = rune('A')`, `rune('A')`, `rune`, `65`},
107 {`package c2c; type T rune; var _ = T('A')`, `T('A')`, `c2c.T`, `65`},
108
109 {`package c3a; var _ = float32(0.)`, `0.`, `float32`, `0`},
110 {`package c3b; var _ = float32(0.)`, `float32(0.)`, `float32`, `0`},
111 {`package c3c; type T float32; var _ = T(0.)`, `T(0.)`, `c3c.T`, `0`},
112
113 {`package c4a; var _ = complex64(0i)`, `0i`, `complex64`, `(0 + 0i)`},
114 {`package c4b; var _ = complex64(0i)`, `complex64(0i)`, `complex64`, `(0 + 0i)`},
115 {`package c4c; type T complex64; var _ = T(0i)`, `T(0i)`, `c4c.T`, `(0 + 0i)`},
116
117 {`package c5a; var _ = string("foo")`, `"foo"`, `string`, `"foo"`},
118 {`package c5b; var _ = string("foo")`, `string("foo")`, `string`, `"foo"`},
119 {`package c5c; type T string; var _ = T("foo")`, `T("foo")`, `c5c.T`, `"foo"`},
120 {`package c5d; var _ = string(65)`, `65`, `untyped int`, `65`},
121 {`package c5e; var _ = string('A')`, `'A'`, `untyped rune`, `65`},
122 {`package c5f; type T string; var _ = T('A')`, `'A'`, `untyped rune`, `65`},
123
124 {`package d0; var _ = []byte("foo")`, `"foo"`, `string`, `"foo"`},
125 {`package d1; var _ = []byte(string("foo"))`, `"foo"`, `string`, `"foo"`},
126 {`package d2; var _ = []byte(string("foo"))`, `string("foo")`, `string`, `"foo"`},
127 {`package d3; type T []byte; var _ = T("foo")`, `"foo"`, `string`, `"foo"`},
128
129 {`package e0; const _ = float32( 1e-200)`, `float32(1e-200)`, `float32`, `0`},
130 {`package e1; const _ = float32(-1e-200)`, `float32(-1e-200)`, `float32`, `0`},
131 {`package e2; const _ = float64( 1e-2000)`, `float64(1e-2000)`, `float64`, `0`},
132 {`package e3; const _ = float64(-1e-2000)`, `float64(-1e-2000)`, `float64`, `0`},
133 {`package e4; const _ = complex64( 1e-200)`, `complex64(1e-200)`, `complex64`, `(0 + 0i)`},
134 {`package e5; const _ = complex64(-1e-200)`, `complex64(-1e-200)`, `complex64`, `(0 + 0i)`},
135 {`package e6; const _ = complex128( 1e-2000)`, `complex128(1e-2000)`, `complex128`, `(0 + 0i)`},
136 {`package e7; const _ = complex128(-1e-2000)`, `complex128(-1e-2000)`, `complex128`, `(0 + 0i)`},
137
138 {`package f0 ; var _ float32 = 1e-200`, `1e-200`, `float32`, `0`},
139 {`package f1 ; var _ float32 = -1e-200`, `-1e-200`, `float32`, `0`},
140 {`package f2a; var _ float64 = 1e-2000`, `1e-2000`, `float64`, `0`},
141 {`package f3a; var _ float64 = -1e-2000`, `-1e-2000`, `float64`, `0`},
142 {`package f2b; var _ = 1e-2000`, `1e-2000`, `float64`, `0`},
143 {`package f3b; var _ = -1e-2000`, `-1e-2000`, `float64`, `0`},
144 {`package f4 ; var _ complex64 = 1e-200 `, `1e-200`, `complex64`, `(0 + 0i)`},
145 {`package f5 ; var _ complex64 = -1e-200 `, `-1e-200`, `complex64`, `(0 + 0i)`},
146 {`package f6a; var _ complex128 = 1e-2000i`, `1e-2000i`, `complex128`, `(0 + 0i)`},
147 {`package f7a; var _ complex128 = -1e-2000i`, `-1e-2000i`, `complex128`, `(0 + 0i)`},
148 {`package f6b; var _ = 1e-2000i`, `1e-2000i`, `complex128`, `(0 + 0i)`},
149 {`package f7b; var _ = -1e-2000i`, `-1e-2000i`, `complex128`, `(0 + 0i)`},
150
151 {`package g0; const (a = len([iota]int{}); b; c); const _ = c`, `c`, `int`, `2`}, // go.dev/issue/22341
152 {`package g1; var(j int32; s int; n = 1.0<<s == j)`, `1.0`, `int32`, `1`}, // go.dev/issue/48422
153 }
154
155 for _, test := range tests {
156 info := Info{
157 Types: make(map[ast.Expr]TypeAndValue),
158 }
159 name := mustTypecheck(test.src, nil, &info).Name()
160
161 // look for expression
162 var expr ast.Expr
163 for e := range info.Types {
164 if ExprString(e) == test.expr {
165 expr = e
166 break
167 }
168 }
169 if expr == nil {
170 t.Errorf("package %s: no expression found for %s", name, test.expr)
171 continue
172 }
173 tv := info.Types[expr]
174
175 // check that type is correct
176 if got := tv.Type.String(); got != test.typ {
177 t.Errorf("package %s: got type %s; want %s", name, got, test.typ)
178 continue
179 }
180
181 // if we have a constant, check that value is correct
182 if tv.Value != nil {
183 if got := tv.Value.ExactString(); got != test.val {
184 t.Errorf("package %s: got value %s; want %s", name, got, test.val)
185 }
186 } else {
187 if test.val != "" {
188 t.Errorf("package %s: no constant found; want %s", name, test.val)
189 }
190 }
191 }
192 }
193
194 func TestTypesInfo(t *testing.T) {
195 // Test sources that are not expected to typecheck must start with the broken prefix.
196 const broken = "package broken_"
197
198 var tests = []struct {
199 src string
200 expr string // expression
201 typ string // value type
202 }{
203 // single-valued expressions of untyped constants
204 {`package b0; var x interface{} = false`, `false`, `bool`},
205 {`package b1; var x interface{} = 0`, `0`, `int`},
206 {`package b2; var x interface{} = 0.`, `0.`, `float64`},
207 {`package b3; var x interface{} = 0i`, `0i`, `complex128`},
208 {`package b4; var x interface{} = "foo"`, `"foo"`, `string`},
209
210 // uses of nil
211 {`package n0; var _ *int = nil`, `nil`, `untyped nil`},
212 {`package n1; var _ func() = nil`, `nil`, `untyped nil`},
213 {`package n2; var _ []byte = nil`, `nil`, `untyped nil`},
214 {`package n3; var _ map[int]int = nil`, `nil`, `untyped nil`},
215 {`package n4; var _ chan int = nil`, `nil`, `untyped nil`},
216 {`package n5; var _ interface{} = nil`, `nil`, `untyped nil`},
217 {`package n6; import "unsafe"; var _ unsafe.Pointer = nil`, `nil`, `untyped nil`},
218
219 {`package n10; var (x *int; _ = x == nil)`, `nil`, `untyped nil`},
220 {`package n11; var (x func(); _ = x == nil)`, `nil`, `untyped nil`},
221 {`package n12; var (x []byte; _ = x == nil)`, `nil`, `untyped nil`},
222 {`package n13; var (x map[int]int; _ = x == nil)`, `nil`, `untyped nil`},
223 {`package n14; var (x chan int; _ = x == nil)`, `nil`, `untyped nil`},
224 {`package n15; var (x interface{}; _ = x == nil)`, `nil`, `untyped nil`},
225 {`package n15; import "unsafe"; var (x unsafe.Pointer; _ = x == nil)`, `nil`, `untyped nil`},
226
227 {`package n20; var _ = (*int)(nil)`, `nil`, `untyped nil`},
228 {`package n21; var _ = (func())(nil)`, `nil`, `untyped nil`},
229 {`package n22; var _ = ([]byte)(nil)`, `nil`, `untyped nil`},
230 {`package n23; var _ = (map[int]int)(nil)`, `nil`, `untyped nil`},
231 {`package n24; var _ = (chan int)(nil)`, `nil`, `untyped nil`},
232 {`package n25; var _ = (interface{})(nil)`, `nil`, `untyped nil`},
233 {`package n26; import "unsafe"; var _ = unsafe.Pointer(nil)`, `nil`, `untyped nil`},
234
235 {`package n30; func f(*int) { f(nil) }`, `nil`, `untyped nil`},
236 {`package n31; func f(func()) { f(nil) }`, `nil`, `untyped nil`},
237 {`package n32; func f([]byte) { f(nil) }`, `nil`, `untyped nil`},
238 {`package n33; func f(map[int]int) { f(nil) }`, `nil`, `untyped nil`},
239 {`package n34; func f(chan int) { f(nil) }`, `nil`, `untyped nil`},
240 {`package n35; func f(interface{}) { f(nil) }`, `nil`, `untyped nil`},
241 {`package n35; import "unsafe"; func f(unsafe.Pointer) { f(nil) }`, `nil`, `untyped nil`},
242
243 // comma-ok expressions
244 {`package p0; var x interface{}; var _, _ = x.(int)`,
245 `x.(int)`,
246 `(int, bool)`,
247 },
248 {`package p1; var x interface{}; func _() { _, _ = x.(int) }`,
249 `x.(int)`,
250 `(int, bool)`,
251 },
252 {`package p2a; type mybool bool; var m map[string]complex128; var b mybool; func _() { _, b = m["foo"] }`,
253 `m["foo"]`,
254 `(complex128, p2a.mybool)`,
255 },
256 {`package p2b; var m map[string]complex128; var b bool; func _() { _, b = m["foo"] }`,
257 `m["foo"]`,
258 `(complex128, bool)`,
259 },
260 {`package p3; var c chan string; var _, _ = <-c`,
261 `<-c`,
262 `(string, bool)`,
263 },
264
265 // go.dev/issue/6796
266 {`package issue6796_a; var x interface{}; var _, _ = (x.(int))`,
267 `x.(int)`,
268 `(int, bool)`,
269 },
270 {`package issue6796_b; var c chan string; var _, _ = (<-c)`,
271 `(<-c)`,
272 `(string, bool)`,
273 },
274 {`package issue6796_c; var c chan string; var _, _ = (<-c)`,
275 `<-c`,
276 `(string, bool)`,
277 },
278 {`package issue6796_d; var c chan string; var _, _ = ((<-c))`,
279 `(<-c)`,
280 `(string, bool)`,
281 },
282 {`package issue6796_e; func f(c chan string) { _, _ = ((<-c)) }`,
283 `(<-c)`,
284 `(string, bool)`,
285 },
286
287 // go.dev/issue/7060
288 {`package issue7060_a; var ( m map[int]string; x, ok = m[0] )`,
289 `m[0]`,
290 `(string, bool)`,
291 },
292 {`package issue7060_b; var ( m map[int]string; x, ok interface{} = m[0] )`,
293 `m[0]`,
294 `(string, bool)`,
295 },
296 {`package issue7060_c; func f(x interface{}, ok bool, m map[int]string) { x, ok = m[0] }`,
297 `m[0]`,
298 `(string, bool)`,
299 },
300 {`package issue7060_d; var ( ch chan string; x, ok = <-ch )`,
301 `<-ch`,
302 `(string, bool)`,
303 },
304 {`package issue7060_e; var ( ch chan string; x, ok interface{} = <-ch )`,
305 `<-ch`,
306 `(string, bool)`,
307 },
308 {`package issue7060_f; func f(x interface{}, ok bool, ch chan string) { x, ok = <-ch }`,
309 `<-ch`,
310 `(string, bool)`,
311 },
312
313 // go.dev/issue/28277
314 {`package issue28277_a; func f(...int)`,
315 `...int`,
316 `[]int`,
317 },
318 {`package issue28277_b; func f(a, b int, c ...[]struct{})`,
319 `...[]struct{}`,
320 `[][]struct{}`,
321 },
322
323 // go.dev/issue/47243
324 {`package issue47243_a; var x int32; var _ = x << 3`, `3`, `untyped int`},
325 {`package issue47243_b; var x int32; var _ = x << 3.`, `3.`, `untyped float`},
326 {`package issue47243_c; var x int32; var _ = 1 << x`, `1 << x`, `int`},
327 {`package issue47243_d; var x int32; var _ = 1 << x`, `1`, `int`},
328 {`package issue47243_e; var x int32; var _ = 1 << 2`, `1`, `untyped int`},
329 {`package issue47243_f; var x int32; var _ = 1 << 2`, `2`, `untyped int`},
330 {`package issue47243_g; var x int32; var _ = int(1) << 2`, `2`, `untyped int`},
331 {`package issue47243_h; var x int32; var _ = 1 << (2 << x)`, `1`, `int`},
332 {`package issue47243_i; var x int32; var _ = 1 << (2 << x)`, `(2 << x)`, `untyped int`},
333 {`package issue47243_j; var x int32; var _ = 1 << (2 << x)`, `2`, `untyped int`},
334
335 // tests for broken code that doesn't type-check
336 {broken + `x0; func _() { var x struct {f string}; x.f := 0 }`, `x.f`, `string`},
337 {broken + `x1; func _() { var z string; type x struct {f string}; y := &x{q: z}}`, `z`, `string`},
338 {broken + `x2; func _() { var a, b string; type x struct {f string}; z := &x{f: a, f: b,}}`, `b`, `string`},
339 {broken + `x3; var x = panic("");`, `panic`, `func(interface{})`},
340 {`package x4; func _() { panic("") }`, `panic`, `func(interface{})`},
341 {broken + `x5; func _() { var x map[string][...]int; x = map[string][...]int{"": {1,2,3}} }`, `x`, `map[string]invalid type`},
342
343 // parameterized functions
344 {`package p0; func f[T any](T) {}; var _ = f[int]`, `f`, `func[T any](T)`},
345 {`package p1; func f[T any](T) {}; var _ = f[int]`, `f[int]`, `func(int)`},
346 {`package p2; func f[T any](T) {}; func _() { f(42) }`, `f`, `func(int)`},
347 {`package p3; func f[T any](T) {}; func _() { f[int](42) }`, `f[int]`, `func(int)`},
348 {`package p4; func f[T any](T) {}; func _() { f[int](42) }`, `f`, `func[T any](T)`},
349 {`package p5; func f[T any](T) {}; func _() { f(42) }`, `f(42)`, `()`},
350
351 // type parameters
352 {`package t0; type t[] int; var _ t`, `t`, `t0.t`}, // t[] is a syntax error that is ignored in this test in favor of t
353 {`package t1; type t[P any] int; var _ t[int]`, `t`, `t1.t[P any]`},
354 {`package t2; type t[P interface{}] int; var _ t[int]`, `t`, `t2.t[P interface{}]`},
355 {`package t3; type t[P, Q interface{}] int; var _ t[int, int]`, `t`, `t3.t[P, Q interface{}]`},
356 {broken + `t4; type t[P, Q interface{ m() }] int; var _ t[int, int]`, `t`, `broken_t4.t[P, Q interface{m()}]`},
357
358 // instantiated types must be sanitized
359 {`package g0; type t[P any] int; var x struct{ f t[int] }; var _ = x.f`, `x.f`, `g0.t[int]`},
360
361 // go.dev/issue/45096
362 {`package issue45096; func _[T interface{ ~int8 | ~int16 | ~int32 }](x T) { _ = x < 0 }`, `0`, `T`},
363
364 // go.dev/issue/47895
365 {`package p; import "unsafe"; type S struct { f int }; var s S; var _ = unsafe.Offsetof(s.f)`, `s.f`, `int`},
366
367 // go.dev/issue/74303. Note that interface field types are synthetic, so
368 // even though `func()` doesn't appear in the source, it appears in the
369 // syntax tree.
370 {`package p; type T interface { M(int) }`, `func(int)`, `func(int)`},
371
372 // go.dev/issue/50093
373 {`package u0a; func _[_ interface{int}]() {}`, `int`, `int`},
374 {`package u1a; func _[_ interface{~int}]() {}`, `~int`, `~int`},
375 {`package u2a; func _[_ interface{int | string}]() {}`, `int | string`, `int | string`},
376 {`package u3a; func _[_ interface{int | string | ~bool}]() {}`, `int | string | ~bool`, `int | string | ~bool`},
377 {`package u3a; func _[_ interface{int | string | ~bool}]() {}`, `int | string`, `int | string`},
378 {`package u3a; func _[_ interface{int | string | ~bool}]() {}`, `~bool`, `~bool`},
379 {`package u3a; func _[_ interface{int | string | ~float64|~bool}]() {}`, `int | string | ~float64`, `int | string | ~float64`},
380
381 {`package u0b; func _[_ int]() {}`, `int`, `int`},
382 {`package u1b; func _[_ ~int]() {}`, `~int`, `~int`},
383 {`package u2b; func _[_ int | string]() {}`, `int | string`, `int | string`},
384 {`package u3b; func _[_ int | string | ~bool]() {}`, `int | string | ~bool`, `int | string | ~bool`},
385 {`package u3b; func _[_ int | string | ~bool]() {}`, `int | string`, `int | string`},
386 {`package u3b; func _[_ int | string | ~bool]() {}`, `~bool`, `~bool`},
387 {`package u3b; func _[_ int | string | ~float64|~bool]() {}`, `int | string | ~float64`, `int | string | ~float64`},
388
389 {`package u0c; type _ interface{int}`, `int`, `int`},
390 {`package u1c; type _ interface{~int}`, `~int`, `~int`},
391 {`package u2c; type _ interface{int | string}`, `int | string`, `int | string`},
392 {`package u3c; type _ interface{int | string | ~bool}`, `int | string | ~bool`, `int | string | ~bool`},
393 {`package u3c; type _ interface{int | string | ~bool}`, `int | string`, `int | string`},
394 {`package u3c; type _ interface{int | string | ~bool}`, `~bool`, `~bool`},
395 {`package u3c; type _ interface{int | string | ~float64|~bool}`, `int | string | ~float64`, `int | string | ~float64`},
396
397 // reverse type inference
398 {`package r1; var _ func(int) = g; func g[P any](P) {}`, `g`, `func(int)`},
399 {`package r2; var _ func(int) = g[int]; func g[P any](P) {}`, `g`, `func[P any](P)`}, // go.dev/issues/60212
400 {`package r3; var _ func(int) = g[int]; func g[P any](P) {}`, `g[int]`, `func(int)`},
401 {`package r4; var _ func(int, string) = g; func g[P, Q any](P, Q) {}`, `g`, `func(int, string)`},
402 {`package r5; var _ func(int, string) = g[int]; func g[P, Q any](P, Q) {}`, `g`, `func[P, Q any](P, Q)`}, // go.dev/issues/60212
403 {`package r6; var _ func(int, string) = g[int]; func g[P, Q any](P, Q) {}`, `g[int]`, `func(int, string)`},
404
405 {`package s1; func _() { f(g) }; func f(func(int)) {}; func g[P any](P) {}`, `g`, `func(int)`},
406 {`package s2; func _() { f(g[int]) }; func f(func(int)) {}; func g[P any](P) {}`, `g`, `func[P any](P)`}, // go.dev/issues/60212
407 {`package s3; func _() { f(g[int]) }; func f(func(int)) {}; func g[P any](P) {}`, `g[int]`, `func(int)`},
408 {`package s4; func _() { f(g) }; func f(func(int, string)) {}; func g[P, Q any](P, Q) {}`, `g`, `func(int, string)`},
409 {`package s5; func _() { f(g[int]) }; func f(func(int, string)) {}; func g[P, Q any](P, Q) {}`, `g`, `func[P, Q any](P, Q)`}, // go.dev/issues/60212
410 {`package s6; func _() { f(g[int]) }; func f(func(int, string)) {}; func g[P, Q any](P, Q) {}`, `g[int]`, `func(int, string)`},
411
412 {`package s7; func _() { f(g, h) }; func f[P any](func(int, P), func(P, string)) {}; func g[P any](P, P) {}; func h[P, Q any](P, Q) {}`, `g`, `func(int, int)`},
413 {`package s8; func _() { f(g, h) }; func f[P any](func(int, P), func(P, string)) {}; func g[P any](P, P) {}; func h[P, Q any](P, Q) {}`, `h`, `func(int, string)`},
414 {`package s9; func _() { f(g, h[int]) }; func f[P any](func(int, P), func(P, string)) {}; func g[P any](P, P) {}; func h[P, Q any](P, Q) {}`, `h`, `func[P, Q any](P, Q)`}, // go.dev/issues/60212
415 {`package s10; func _() { f(g, h[int]) }; func f[P any](func(int, P), func(P, string)) {}; func g[P any](P, P) {}; func h[P, Q any](P, Q) {}`, `h[int]`, `func(int, string)`},
416
417 // go.dev/issue/68639
418 // parenthesized and pointer type expressions in various positions
419 // - as variable type, not generic
420 {`package qa1; type T int; var x T`, `T`, `qa1.T`},
421 {`package qa2; type T int; var x (T)`, `T`, `qa2.T`},
422 {`package qa3; type T int; var x (T)`, `(T)`, `qa3.T`},
423 {`package qa4; type T int; var x ((T))`, `T`, `qa4.T`},
424 {`package qa5; type T int; var x ((T))`, `(T)`, `qa5.T`},
425 {`package qa6; type T int; var x ((T))`, `((T))`, `qa6.T`},
426 {`package qa7; type T int; var x *T`, `T`, `qa7.T`},
427 {`package qa8; type T int; var x *T`, `*T`, `*qa8.T`},
428 {`package qa9; type T int; var x (*T)`, `T`, `qa9.T`},
429 {`package qa10; type T int; var x (*T)`, `*T`, `*qa10.T`},
430 {`package qa11; type T int; var x *(T)`, `T`, `qa11.T`},
431 {`package qa12; type T int; var x *(T)`, `(T)`, `qa12.T`},
432 {`package qa13; type T int; var x *(T)`, `*(T)`, `*qa13.T`},
433 {`package qa14; type T int; var x (*(T))`, `(T)`, `qa14.T`},
434 {`package qa15; type T int; var x (*(T))`, `*(T)`, `*qa15.T`},
435 {`package qa16; type T int; var x (*(T))`, `(*(T))`, `*qa16.T`},
436
437 // - as ordinary function parameter, not generic
438 {`package qb1; type T int; func _(T)`, `T`, `qb1.T`},
439 {`package qb2; type T int; func _((T))`, `T`, `qb2.T`},
440 {`package qb3; type T int; func _((T))`, `(T)`, `qb3.T`},
441 {`package qb4; type T int; func _(((T)))`, `T`, `qb4.T`},
442 {`package qb5; type T int; func _(((T)))`, `(T)`, `qb5.T`},
443 {`package qb6; type T int; func _(((T)))`, `((T))`, `qb6.T`},
444 {`package qb7; type T int; func _(*T)`, `T`, `qb7.T`},
445 {`package qb8; type T int; func _(*T)`, `*T`, `*qb8.T`},
446 {`package qb9; type T int; func _((*T))`, `T`, `qb9.T`},
447 {`package qb10; type T int; func _((*T))`, `*T`, `*qb10.T`},
448 {`package qb11; type T int; func _(*(T))`, `T`, `qb11.T`},
449 {`package qb12; type T int; func _(*(T))`, `(T)`, `qb12.T`},
450 {`package qb13; type T int; func _(*(T))`, `*(T)`, `*qb13.T`},
451 {`package qb14; type T int; func _((*(T)))`, `(T)`, `qb14.T`},
452 {`package qb15; type T int; func _((*(T)))`, `*(T)`, `*qb15.T`},
453 {`package qb16; type T int; func _((*(T)))`, `(*(T))`, `*qb16.T`},
454
455 // - as method receiver, not generic
456 {`package qc1; type T int; func (T) _() {}`, `T`, `qc1.T`},
457 {`package qc2; type T int; func ((T)) _() {}`, `T`, `qc2.T`},
458 {`package qc3; type T int; func ((T)) _() {}`, `(T)`, `qc3.T`},
459 {`package qc4; type T int; func (((T))) _() {}`, `T`, `qc4.T`},
460 {`package qc5; type T int; func (((T))) _() {}`, `(T)`, `qc5.T`},
461 {`package qc6; type T int; func (((T))) _() {}`, `((T))`, `qc6.T`},
462 {`package qc7; type T int; func (*T) _() {}`, `T`, `qc7.T`},
463 {`package qc8; type T int; func (*T) _() {}`, `*T`, `*qc8.T`},
464 {`package qc9; type T int; func ((*T)) _() {}`, `T`, `qc9.T`},
465 {`package qc10; type T int; func ((*T)) _() {}`, `*T`, `*qc10.T`},
466 {`package qc11; type T int; func (*(T)) _() {}`, `T`, `qc11.T`},
467 {`package qc12; type T int; func (*(T)) _() {}`, `(T)`, `qc12.T`},
468 {`package qc13; type T int; func (*(T)) _() {}`, `*(T)`, `*qc13.T`},
469 {`package qc14; type T int; func ((*(T))) _() {}`, `(T)`, `qc14.T`},
470 {`package qc15; type T int; func ((*(T))) _() {}`, `*(T)`, `*qc15.T`},
471 {`package qc16; type T int; func ((*(T))) _() {}`, `(*(T))`, `*qc16.T`},
472
473 // - as variable type, generic
474 {`package qd1; type T[_ any] int; var x T[int]`, `T`, `qd1.T[_ any]`},
475 {`package qd2; type T[_ any] int; var x (T[int])`, `T[int]`, `qd2.T[int]`},
476 {`package qd3; type T[_ any] int; var x (T[int])`, `(T[int])`, `qd3.T[int]`},
477 {`package qd4; type T[_ any] int; var x ((T[int]))`, `T`, `qd4.T[_ any]`},
478 {`package qd5; type T[_ any] int; var x ((T[int]))`, `(T[int])`, `qd5.T[int]`},
479 {`package qd6; type T[_ any] int; var x ((T[int]))`, `((T[int]))`, `qd6.T[int]`},
480 {`package qd7; type T[_ any] int; var x *T[int]`, `T`, `qd7.T[_ any]`},
481 {`package qd8; type T[_ any] int; var x *T[int]`, `*T[int]`, `*qd8.T[int]`},
482 {`package qd9; type T[_ any] int; var x (*T[int])`, `T`, `qd9.T[_ any]`},
483 {`package qd10; type T[_ any] int; var x (*T[int])`, `*T[int]`, `*qd10.T[int]`},
484 {`package qd11; type T[_ any] int; var x *(T[int])`, `T[int]`, `qd11.T[int]`},
485 {`package qd12; type T[_ any] int; var x *(T[int])`, `(T[int])`, `qd12.T[int]`},
486 {`package qd13; type T[_ any] int; var x *(T[int])`, `*(T[int])`, `*qd13.T[int]`},
487 {`package qd14; type T[_ any] int; var x (*(T[int]))`, `(T[int])`, `qd14.T[int]`},
488 {`package qd15; type T[_ any] int; var x (*(T[int]))`, `*(T[int])`, `*qd15.T[int]`},
489 {`package qd16; type T[_ any] int; var x (*(T[int]))`, `(*(T[int]))`, `*qd16.T[int]`},
490
491 // - as ordinary function parameter, generic
492 {`package qe1; type T[_ any] int; func _(T[int])`, `T`, `qe1.T[_ any]`},
493 {`package qe2; type T[_ any] int; func _((T[int]))`, `T[int]`, `qe2.T[int]`},
494 {`package qe3; type T[_ any] int; func _((T[int]))`, `(T[int])`, `qe3.T[int]`},
495 {`package qe4; type T[_ any] int; func _(((T[int])))`, `T`, `qe4.T[_ any]`},
496 {`package qe5; type T[_ any] int; func _(((T[int])))`, `(T[int])`, `qe5.T[int]`},
497 {`package qe6; type T[_ any] int; func _(((T[int])))`, `((T[int]))`, `qe6.T[int]`},
498 {`package qe7; type T[_ any] int; func _(*T[int])`, `T`, `qe7.T[_ any]`},
499 {`package qe8; type T[_ any] int; func _(*T[int])`, `*T[int]`, `*qe8.T[int]`},
500 {`package qe9; type T[_ any] int; func _((*T[int]))`, `T`, `qe9.T[_ any]`},
501 {`package qe10; type T[_ any] int; func _((*T[int]))`, `*T[int]`, `*qe10.T[int]`},
502 {`package qe11; type T[_ any] int; func _(*(T[int]))`, `T[int]`, `qe11.T[int]`},
503 {`package qe12; type T[_ any] int; func _(*(T[int]))`, `(T[int])`, `qe12.T[int]`},
504 {`package qe13; type T[_ any] int; func _(*(T[int]))`, `*(T[int])`, `*qe13.T[int]`},
505 {`package qe14; type T[_ any] int; func _((*(T[int])))`, `(T[int])`, `qe14.T[int]`},
506 {`package qe15; type T[_ any] int; func _((*(T[int])))`, `*(T[int])`, `*qe15.T[int]`},
507 {`package qe16; type T[_ any] int; func _((*(T[int])))`, `(*(T[int]))`, `*qe16.T[int]`},
508
509 // - as method receiver, generic
510 {`package qf1; type T[_ any] int; func (T[_]) _() {}`, `T`, `qf1.T[_ any]`},
511 {`package qf2; type T[_ any] int; func ((T[_])) _() {}`, `T[_]`, `qf2.T[_]`},
512 {`package qf3; type T[_ any] int; func ((T[_])) _() {}`, `(T[_])`, `qf3.T[_]`},
513 {`package qf4; type T[_ any] int; func (((T[_]))) _() {}`, `T`, `qf4.T[_ any]`},
514 {`package qf5; type T[_ any] int; func (((T[_]))) _() {}`, `(T[_])`, `qf5.T[_]`},
515 {`package qf6; type T[_ any] int; func (((T[_]))) _() {}`, `((T[_]))`, `qf6.T[_]`},
516 {`package qf7; type T[_ any] int; func (*T[_]) _() {}`, `T`, `qf7.T[_ any]`},
517 {`package qf8; type T[_ any] int; func (*T[_]) _() {}`, `*T[_]`, `*qf8.T[_]`},
518 {`package qf9; type T[_ any] int; func ((*T[_])) _() {}`, `T`, `qf9.T[_ any]`},
519 {`package qf10; type T[_ any] int; func ((*T[_])) _() {}`, `*T[_]`, `*qf10.T[_]`},
520 {`package qf11; type T[_ any] int; func (*(T[_])) _() {}`, `T[_]`, `qf11.T[_]`},
521 {`package qf12; type T[_ any] int; func (*(T[_])) _() {}`, `(T[_])`, `qf12.T[_]`},
522 {`package qf13; type T[_ any] int; func (*(T[_])) _() {}`, `*(T[_])`, `*qf13.T[_]`},
523 {`package qf14; type T[_ any] int; func ((*(T[_]))) _() {}`, `(T[_])`, `qf14.T[_]`},
524 {`package qf15; type T[_ any] int; func ((*(T[_]))) _() {}`, `*(T[_])`, `*qf15.T[_]`},
525 {`package qf16; type T[_ any] int; func ((*(T[_]))) _() {}`, `(*(T[_]))`, `*qf16.T[_]`},
526
527 // For historic reasons, type parameters in receiver type expressions
528 // are considered both definitions and uses and thus also show up in
529 // the Info.Types map (see go.dev/issue/68670).
530 {`package t1; type T[_ any] int; func (T[P]) _() {}`, `P`, `P`},
531 {`package t2; type T[_, _ any] int; func (T[P, Q]) _() {}`, `P`, `P`},
532 {`package t3; type T[_, _ any] int; func (T[P, Q]) _() {}`, `Q`, `Q`},
533 }
534
535 for _, test := range tests {
536 info := Info{Types: make(map[ast.Expr]TypeAndValue)}
537 var name string
538 if strings.HasPrefix(test.src, broken) {
539 pkg, err := typecheck(test.src, nil, &info)
540 if err == nil {
541 t.Errorf("package %s: expected to fail but passed", pkg.Name())
542 continue
543 }
544 if pkg != nil {
545 name = pkg.Name()
546 }
547 } else {
548 name = mustTypecheck(test.src, nil, &info).Name()
549 }
550
551 // look for expression type
552 var typ Type
553 for e, tv := range info.Types {
554 if ExprString(e) == test.expr {
555 typ = tv.Type
556 break
557 }
558 }
559 if typ == nil {
560 t.Errorf("package %s: no type found for %s", name, test.expr)
561 continue
562 }
563
564 // check that type is correct
565 if got := typ.String(); got != test.typ {
566 t.Errorf("package %s: expr = %s: got %s; want %s", name, test.expr, got, test.typ)
567 }
568 }
569 }
570
571 func TestInstanceInfo(t *testing.T) {
572 const lib = `package lib
573
574 func F[P any](P) {}
575
576 type T[P any] []P
577 `
578
579 type testInst struct {
580 name string
581 targs []string
582 typ string
583 }
584
585 var tests = []struct {
586 src string
587 instances []testInst // recorded instances in source order
588 }{
589 {`package p0; func f[T any](T) {}; func _() { f(42) }`,
590 []testInst{{`f`, []string{`int`}, `func(int)`}},
591 },
592 {`package p1; func f[T any](T) T { panic(0) }; func _() { f('@') }`,
593 []testInst{{`f`, []string{`rune`}, `func(rune) rune`}},
594 },
595 {`package p2; func f[T any](...T) T { panic(0) }; func _() { f(0i) }`,
596 []testInst{{`f`, []string{`complex128`}, `func(...complex128) complex128`}},
597 },
598 {`package p3; func f[A, B, C any](A, *B, []C) {}; func _() { f(1.2, new(string), []byte{}) }`,
599 []testInst{{`f`, []string{`float64`, `string`, `byte`}, `func(float64, *string, []byte)`}},
600 },
601 {`package p4; func f[A, B any](A, *B, ...[]B) {}; func _() { f(1.2, new(byte)) }`,
602 []testInst{{`f`, []string{`float64`, `byte`}, `func(float64, *byte, ...[]byte)`}},
603 },
604
605 {`package s1; func f[T any, P interface{*T}](x T) {}; func _(x string) { f(x) }`,
606 []testInst{{`f`, []string{`string`, `*string`}, `func(x string)`}},
607 },
608 {`package s2; func f[T any, P interface{*T}](x []T) {}; func _(x []int) { f(x) }`,
609 []testInst{{`f`, []string{`int`, `*int`}, `func(x []int)`}},
610 },
611 {`package s3; type C[T any] interface{chan<- T}; func f[T any, P C[T]](x []T) {}; func _(x []int) { f(x) }`,
612 []testInst{
613 {`C`, []string{`T`}, `interface{chan<- T}`},
614 {`f`, []string{`int`, `chan<- int`}, `func(x []int)`},
615 },
616 },
617 {`package s4; type C[T any] interface{chan<- T}; func f[T any, P C[T], Q C[[]*P]](x []T) {}; func _(x []int) { f(x) }`,
618 []testInst{
619 {`C`, []string{`T`}, `interface{chan<- T}`},
620 {`C`, []string{`[]*P`}, `interface{chan<- []*P}`},
621 {`f`, []string{`int`, `chan<- int`, `chan<- []*chan<- int`}, `func(x []int)`},
622 },
623 },
624
625 {`package t1; func f[T any, P interface{*T}]() T { panic(0) }; func _() { _ = f[string] }`,
626 []testInst{{`f`, []string{`string`, `*string`}, `func() string`}},
627 },
628 {`package t2; func f[T any, P interface{*T}]() T { panic(0) }; func _() { _ = (f[string]) }`,
629 []testInst{{`f`, []string{`string`, `*string`}, `func() string`}},
630 },
631 {`package t3; type C[T any] interface{chan<- T}; func f[T any, P C[T], Q C[[]*P]]() []T { return nil }; func _() { _ = f[int] }`,
632 []testInst{
633 {`C`, []string{`T`}, `interface{chan<- T}`},
634 {`C`, []string{`[]*P`}, `interface{chan<- []*P}`},
635 {`f`, []string{`int`, `chan<- int`, `chan<- []*chan<- int`}, `func() []int`},
636 },
637 },
638 {`package t4; type C[T any] interface{chan<- T}; func f[T any, P C[T], Q C[[]*P]]() []T { return nil }; func _() { _ = (f[int]) }`,
639 []testInst{
640 {`C`, []string{`T`}, `interface{chan<- T}`},
641 {`C`, []string{`[]*P`}, `interface{chan<- []*P}`},
642 {`f`, []string{`int`, `chan<- int`, `chan<- []*chan<- int`}, `func() []int`},
643 },
644 },
645 {`package i0; import "lib"; func _() { lib.F(42) }`,
646 []testInst{{`F`, []string{`int`}, `func(int)`}},
647 },
648
649 {`package duplfunc0; func f[T any](T) {}; func _() { f(42); f("foo"); f[int](3) }`,
650 []testInst{
651 {`f`, []string{`int`}, `func(int)`},
652 {`f`, []string{`string`}, `func(string)`},
653 {`f`, []string{`int`}, `func(int)`},
654 },
655 },
656 {`package duplfunc1; import "lib"; func _() { lib.F(42); lib.F("foo"); lib.F(3) }`,
657 []testInst{
658 {`F`, []string{`int`}, `func(int)`},
659 {`F`, []string{`string`}, `func(string)`},
660 {`F`, []string{`int`}, `func(int)`},
661 },
662 },
663
664 {`package type0; type T[P interface{~int}] struct{ x P }; var _ T[int]`,
665 []testInst{{`T`, []string{`int`}, `struct{x int}`}},
666 },
667 {`package type1; type T[P interface{~int}] struct{ x P }; var _ (T[int])`,
668 []testInst{{`T`, []string{`int`}, `struct{x int}`}},
669 },
670 {`package type2; type T[P interface{~int}] struct{ x P }; var _ T[(int)]`,
671 []testInst{{`T`, []string{`int`}, `struct{x int}`}},
672 },
673 {`package type3; type T[P1 interface{~[]P2}, P2 any] struct{ x P1; y P2 }; var _ T[[]int, int]`,
674 []testInst{{`T`, []string{`[]int`, `int`}, `struct{x []int; y int}`}},
675 },
676 {`package type4; import "lib"; var _ lib.T[int]`,
677 []testInst{{`T`, []string{`int`}, `[]int`}},
678 },
679
680 {`package dupltype0; type T[P interface{~int}] struct{ x P }; var x T[int]; var y T[int]`,
681 []testInst{
682 {`T`, []string{`int`}, `struct{x int}`},
683 {`T`, []string{`int`}, `struct{x int}`},
684 },
685 },
686 {`package dupltype1; type T[P ~int] struct{ x P }; func (r *T[Q]) add(z T[Q]) { r.x += z.x }`,
687 []testInst{
688 {`T`, []string{`Q`}, `struct{x Q}`},
689 {`T`, []string{`Q`}, `struct{x Q}`},
690 },
691 },
692 {`package dupltype1; import "lib"; var x lib.T[int]; var y lib.T[int]; var z lib.T[string]`,
693 []testInst{
694 {`T`, []string{`int`}, `[]int`},
695 {`T`, []string{`int`}, `[]int`},
696 {`T`, []string{`string`}, `[]string`},
697 },
698 },
699 {`package issue51803; func foo[T any](T) {}; func _() { foo[int]( /* leave arg away on purpose */ ) }`,
700 []testInst{{`foo`, []string{`int`}, `func(int)`}},
701 },
702
703 // reverse type inference
704 {`package reverse1a; var f func(int) = g; func g[P any](P) {}`,
705 []testInst{{`g`, []string{`int`}, `func(int)`}},
706 },
707 {`package reverse1b; func f(func(int)) {}; func g[P any](P) {}; func _() { f(g) }`,
708 []testInst{{`g`, []string{`int`}, `func(int)`}},
709 },
710 {`package reverse2a; var f func(int, string) = g; func g[P, Q any](P, Q) {}`,
711 []testInst{{`g`, []string{`int`, `string`}, `func(int, string)`}},
712 },
713 {`package reverse2b; func f(func(int, string)) {}; func g[P, Q any](P, Q) {}; func _() { f(g) }`,
714 []testInst{{`g`, []string{`int`, `string`}, `func(int, string)`}},
715 },
716 {`package reverse2c; func f(func(int, string)) {}; func g[P, Q any](P, Q) {}; func _() { f(g[int]) }`,
717 []testInst{{`g`, []string{`int`, `string`}, `func(int, string)`}},
718 },
719 // reverse3a not possible (cannot assign to generic function outside of argument passing)
720 {`package reverse3b; func f[R any](func(int) R) {}; func g[P any](P) string { return "" }; func _() { f(g) }`,
721 []testInst{
722 {`f`, []string{`string`}, `func(func(int) string)`},
723 {`g`, []string{`int`}, `func(int) string`},
724 },
725 },
726 {`package reverse4a; var _, _ func([]int, *float32) = g, h; func g[P, Q any]([]P, *Q) {}; func h[R any]([]R, *float32) {}`,
727 []testInst{
728 {`g`, []string{`int`, `float32`}, `func([]int, *float32)`},
729 {`h`, []string{`int`}, `func([]int, *float32)`},
730 },
731 },
732 {`package reverse4b; func f(_, _ func([]int, *float32)) {}; func g[P, Q any]([]P, *Q) {}; func h[R any]([]R, *float32) {}; func _() { f(g, h) }`,
733 []testInst{
734 {`g`, []string{`int`, `float32`}, `func([]int, *float32)`},
735 {`h`, []string{`int`}, `func([]int, *float32)`},
736 },
737 },
738 {`package issue59956; func f(func(int), func(string), func(bool)) {}; func g[P any](P) {}; func _() { f(g, g, g) }`,
739 []testInst{
740 {`g`, []string{`int`}, `func(int)`},
741 {`g`, []string{`string`}, `func(string)`},
742 {`g`, []string{`bool`}, `func(bool)`},
743 },
744 },
745 }
746
747 for _, test := range tests {
748 imports := make(testImporter)
749 conf := Config{Importer: imports}
750 instMap := make(map[*ast.Ident]Instance)
751 useMap := make(map[*ast.Ident]Object)
752 makePkg := func(src string) *Package {
753 pkg, err := typecheck(src, &conf, &Info{Instances: instMap, Uses: useMap})
754 // allow error for issue51803
755 if err != nil && (pkg == nil || pkg.Name() != "issue51803") {
756 t.Fatal(err)
757 }
758 imports[pkg.Name()] = pkg
759 return pkg
760 }
761 makePkg(lib)
762 pkg := makePkg(test.src)
763
764 t.Run(pkg.Name(), func(t *testing.T) {
765 // Sort instances in source order for stability.
766 instances := sortedInstances(instMap)
767 if got, want := len(instances), len(test.instances); got != want {
768 t.Fatalf("got %d instances, want %d", got, want)
769 }
770
771 // Pairwise compare with the expected instances.
772 for ii, inst := range instances {
773 var targs []Type
774 for i := 0; i < inst.Inst.TypeArgs.Len(); i++ {
775 targs = append(targs, inst.Inst.TypeArgs.At(i))
776 }
777 typ := inst.Inst.Type
778
779 testInst := test.instances[ii]
780 if got := inst.Ident.Name; got != testInst.name {
781 t.Fatalf("got name %s, want %s", got, testInst.name)
782 }
783 if len(targs) != len(testInst.targs) {
784 t.Fatalf("got %d type arguments; want %d", len(targs), len(testInst.targs))
785 }
786 for i, targ := range targs {
787 if got := targ.String(); got != testInst.targs[i] {
788 t.Errorf("type argument %d: got %s; want %s", i, got, testInst.targs[i])
789 }
790 }
791 if got := typ.Underlying().String(); got != testInst.typ {
792 t.Errorf("package %s: got %s; want %s", pkg.Name(), got, testInst.typ)
793 }
794
795 // Verify the invariant that re-instantiating the corresponding generic
796 // type with TypeArgs results in an identical instance.
797 ptype := useMap[inst.Ident].Type()
798 lister, _ := ptype.(interface{ TypeParams() *TypeParamList })
799 if lister == nil || lister.TypeParams().Len() == 0 {
800 t.Fatalf("info.Types[%v] = %v, want parameterized type", inst.Ident, ptype)
801 }
802 inst2, err := Instantiate(nil, ptype, targs, true)
803 if err != nil {
804 t.Errorf("Instantiate(%v, %v) failed: %v", ptype, targs, err)
805 }
806 if !Identical(inst.Inst.Type, inst2) {
807 t.Errorf("%v and %v are not identical", inst.Inst.Type, inst2)
808 }
809 }
810 })
811 }
812 }
813
814 type recordedInstance struct {
815 Ident *ast.Ident
816 Inst Instance
817 }
818
819 func sortedInstances(m map[*ast.Ident]Instance) (instances []recordedInstance) {
820 for id, inst := range m {
821 instances = append(instances, recordedInstance{id, inst})
822 }
823 slices.SortFunc(instances, func(a, b recordedInstance) int {
824 return CmpPos(a.Ident.Pos(), b.Ident.Pos())
825 })
826 return instances
827 }
828
829 func TestDefsInfo(t *testing.T) {
830 var tests = []struct {
831 src string
832 obj string
833 want string
834 }{
835 {`package p0; const x = 42`, `x`, `const p0.x untyped int`},
836 {`package p1; const x int = 42`, `x`, `const p1.x int`},
837 {`package p2; var x int`, `x`, `var p2.x int`},
838 {`package p3; type x int`, `x`, `type p3.x int`},
839 {`package p4; func f()`, `f`, `func p4.f()`},
840 {`package p5; func f() int { x, _ := 1, 2; return x }`, `_`, `var _ int`},
841
842 // Tests using generics.
843 {`package g0; type x[T any] int`, `x`, `type g0.x[T any] int`},
844 {`package g1; func f[T any]() {}`, `f`, `func g1.f[T any]()`},
845 {`package g2; type x[T any] int; func (*x[_]) m() {}`, `m`, `func (*g2.x[_]).m()`},
846
847 // Type parameters in receiver type expressions are definitions.
848 {`package r0; type T[_ any] int; func (T[P]) _() {}`, `P`, `type parameter P any`},
849 {`package r1; type T[_, _ any] int; func (T[P, Q]) _() {}`, `P`, `type parameter P any`},
850 {`package r2; type T[_, _ any] int; func (T[P, Q]) _() {}`, `Q`, `type parameter Q any`},
851 }
852
853 for _, test := range tests {
854 info := Info{
855 Defs: make(map[*ast.Ident]Object),
856 }
857 name := mustTypecheck(test.src, nil, &info).Name()
858
859 // find object
860 var def Object
861 for id, obj := range info.Defs {
862 if id.Name == test.obj {
863 def = obj
864 break
865 }
866 }
867 if def == nil {
868 t.Errorf("package %s: %s not found", name, test.obj)
869 continue
870 }
871
872 if got := def.String(); got != test.want {
873 t.Errorf("package %s: got %s; want %s", name, got, test.want)
874 }
875 }
876 }
877
878 func TestUsesInfo(t *testing.T) {
879 var tests = []struct {
880 src string
881 obj string
882 want string
883 }{
884 {`package p0; func _() { _ = x }; const x = 42`, `x`, `const p0.x untyped int`},
885 {`package p1; func _() { _ = x }; const x int = 42`, `x`, `const p1.x int`},
886 {`package p2; func _() { _ = x }; var x int`, `x`, `var p2.x int`},
887 {`package p3; func _() { type _ x }; type x int`, `x`, `type p3.x int`},
888 {`package p4; func _() { _ = f }; func f()`, `f`, `func p4.f()`},
889
890 // Tests using generics.
891 {`package g0; func _[T any]() { _ = x }; const x = 42`, `x`, `const g0.x untyped int`},
892 {`package g1; func _[T any](x T) { }`, `T`, `type parameter T any`},
893 {`package g2; type N[A any] int; var _ N[int]`, `N`, `type g2.N[A any] int`},
894 {`package g3; type N[A any] int; func (N[_]) m() {}`, `N`, `type g3.N[A any] int`},
895
896 // Uses of fields are instantiated.
897 {`package s1; type N[A any] struct{ a A }; var f = N[int]{}.a`, `a`, `field a int`},
898 {`package s2; type N[A any] struct{ a A }; func (r N[B]) m(b B) { r.a = b }`, `a`, `field a B`},
899
900 // Uses of methods are uses of the instantiated method.
901 {`package m0; type N[A any] int; func (r N[B]) m() { r.n() }; func (N[C]) n() {}`, `n`, `func (m0.N[B]).n()`},
902 {`package m1; type N[A any] int; func (r N[B]) m() { }; var f = N[int].m`, `m`, `func (m1.N[int]).m()`},
903 {`package m2; func _[A any](v interface{ m() A }) { v.m() }`, `m`, `func (interface).m() A`},
904 {`package m3; func f[A any]() interface{ m() A } { return nil }; var _ = f[int]().m()`, `m`, `func (interface).m() int`},
905 {`package m4; type T[A any] func() interface{ m() A }; var x T[int]; var y = x().m`, `m`, `func (interface).m() int`},
906 {`package m5; type T[A any] interface{ m() A }; func _[B any](t T[B]) { t.m() }`, `m`, `func (m5.T[B]).m() B`},
907 {`package m6; type T[A any] interface{ m() }; func _[B any](t T[B]) { t.m() }`, `m`, `func (m6.T[B]).m()`},
908 {`package m7; type T[A any] interface{ m() A }; func _(t T[int]) { t.m() }`, `m`, `func (m7.T[int]).m() int`},
909 {`package m8; type T[A any] interface{ m() }; func _(t T[int]) { t.m() }`, `m`, `func (m8.T[int]).m()`},
910 {`package m9; type T[A any] interface{ m() }; func _(t T[int]) { _ = t.m }`, `m`, `func (m9.T[int]).m()`},
911 {
912 `package m10; type E[A any] interface{ m() }; type T[B any] interface{ E[B]; n() }; func _(t T[int]) { t.m() }`,
913 `m`,
914 `func (m10.E[int]).m()`,
915 },
916 {`package m11; type T[A any] interface{ m(); n() }; func _(t1 T[int], t2 T[string]) { t1.m(); t2.n() }`, `m`, `func (m11.T[int]).m()`},
917 {`package m12; type T[A any] interface{ m(); n() }; func _(t1 T[int], t2 T[string]) { t1.m(); t2.n() }`, `n`, `func (m12.T[string]).n()`},
918
919 // For historic reasons, type parameters in receiver type expressions
920 // are considered both definitions and uses (see go.dev/issue/68670).
921 {`package r0; type T[_ any] int; func (T[P]) _() {}`, `P`, `type parameter P any`},
922 {`package r1; type T[_, _ any] int; func (T[P, Q]) _() {}`, `P`, `type parameter P any`},
923 {`package r2; type T[_, _ any] int; func (T[P, Q]) _() {}`, `Q`, `type parameter Q any`},
924 }
925
926 for _, test := range tests {
927 info := Info{
928 Uses: make(map[*ast.Ident]Object),
929 }
930 name := mustTypecheck(test.src, nil, &info).Name()
931
932 // find object
933 var use Object
934 for id, obj := range info.Uses {
935 if id.Name == test.obj {
936 if use != nil {
937 panic(fmt.Sprintf("multiple uses of %q", id.Name))
938 }
939 use = obj
940 }
941 }
942 if use == nil {
943 t.Errorf("package %s: %s not found", name, test.obj)
944 continue
945 }
946
947 if got := use.String(); got != test.want {
948 t.Errorf("package %s: got %s; want %s", name, got, test.want)
949 }
950 }
951 }
952
953 func TestGenericMethodInfo(t *testing.T) {
954 src := `package p
955
956 type N[A any] int
957
958 func (r N[B]) m() { r.m(); r.n() }
959
960 func (r *N[C]) n() { }
961 `
962 fset := token.NewFileSet()
963 f := mustParse(fset, src)
964 info := Info{
965 Defs: make(map[*ast.Ident]Object),
966 Uses: make(map[*ast.Ident]Object),
967 Selections: make(map[*ast.SelectorExpr]*Selection),
968 }
969 var conf Config
970 pkg, err := conf.Check("p", fset, []*ast.File{f}, &info)
971 if err != nil {
972 t.Fatal(err)
973 }
974
975 N := pkg.Scope().Lookup("N").Type().(*Named)
976
977 // Find the generic methods stored on N.
978 gm, gn := N.Method(0), N.Method(1)
979 if gm.Name() == "n" {
980 gm, gn = gn, gm
981 }
982
983 // Collect objects from info.
984 var dm, dn *Func // the declared methods
985 var dmm, dmn *Func // the methods used in the body of m
986 for _, decl := range f.Decls {
987 fdecl, ok := decl.(*ast.FuncDecl)
988 if !ok {
989 continue
990 }
991 def := info.Defs[fdecl.Name].(*Func)
992 switch fdecl.Name.Name {
993 case "m":
994 dm = def
995 ast.Inspect(fdecl.Body, func(n ast.Node) bool {
996 if call, ok := n.(*ast.CallExpr); ok {
997 sel := call.Fun.(*ast.SelectorExpr)
998 use := info.Uses[sel.Sel].(*Func)
999 selection := info.Selections[sel]
1000 if selection.Kind() != MethodVal {
1001 t.Errorf("Selection kind = %v, want %v", selection.Kind(), MethodVal)
1002 }
1003 if selection.Obj() != use {
1004 t.Errorf("info.Selections contains %v, want %v", selection.Obj(), use)
1005 }
1006 switch sel.Sel.Name {
1007 case "m":
1008 dmm = use
1009 case "n":
1010 dmn = use
1011 }
1012 }
1013 return true
1014 })
1015 case "n":
1016 dn = def
1017 }
1018 }
1019
1020 if gm != dm {
1021 t.Errorf(`N.Method(...) returns %v for "m", but Info.Defs has %v`, gm, dm)
1022 }
1023 if gn != dn {
1024 t.Errorf(`N.Method(...) returns %v for "m", but Info.Defs has %v`, gm, dm)
1025 }
1026 if dmm != dm {
1027 t.Errorf(`Inside "m", r.m uses %v, want the defined func %v`, dmm, dm)
1028 }
1029 if dmn == dn {
1030 t.Errorf(`Inside "m", r.n uses %v, want a func distinct from %v`, dmm, dm)
1031 }
1032 }
1033
1034 func TestImplicitsInfo(t *testing.T) {
1035 testenv.MustHaveGoBuild(t)
1036
1037 var tests = []struct {
1038 src string
1039 want string
1040 }{
1041 {`package p2; import . "fmt"; var _ = Println`, ""}, // no Implicits entry
1042 {`package p0; import local "fmt"; var _ = local.Println`, ""}, // no Implicits entry
1043 {`package p1; import "fmt"; var _ = fmt.Println`, "importSpec: package fmt"},
1044
1045 {`package p3; func f(x interface{}) { switch x.(type) { case int: } }`, ""}, // no Implicits entry
1046 {`package p4; func f(x interface{}) { switch t := x.(type) { case int: _ = t } }`, "caseClause: var t int"},
1047 {`package p5; func f(x interface{}) { switch t := x.(type) { case int, uint: _ = t } }`, "caseClause: var t interface{}"},
1048 {`package p6; func f(x interface{}) { switch t := x.(type) { default: _ = t } }`, "caseClause: var t interface{}"},
1049
1050 {`package p7; func f(x int) {}`, ""}, // no Implicits entry
1051 {`package p8; func f(int) {}`, "field: var int"},
1052 {`package p9; func f() (complex64) { return 0 }`, "field: var complex64"},
1053 {`package p10; type T struct{}; func (*T) f() {}`, "field: var *p10.T"},
1054
1055 // Tests using generics.
1056 {`package f0; func f[T any](x int) {}`, ""}, // no Implicits entry
1057 {`package f1; func f[T any](int) {}`, "field: var int"},
1058 {`package f2; func f[T any](T) {}`, "field: var T"},
1059 {`package f3; func f[T any]() (complex64) { return 0 }`, "field: var complex64"},
1060 {`package f4; func f[T any](t T) (T) { return t }`, "field: var T"},
1061 {`package t0; type T[A any] struct{}; func (*T[_]) f() {}`, "field: var *t0.T[_]"},
1062 {`package t1; type T[A any] struct{}; func _(x interface{}) { switch t := x.(type) { case T[int]: _ = t } }`, "caseClause: var t t1.T[int]"},
1063 {`package t2; type T[A any] struct{}; func _[P any](x interface{}) { switch t := x.(type) { case T[P]: _ = t } }`, "caseClause: var t t2.T[P]"},
1064 {`package t3; func _[P any](x interface{}) { switch t := x.(type) { case P: _ = t } }`, "caseClause: var t P"},
1065 }
1066
1067 for _, test := range tests {
1068 info := Info{
1069 Implicits: make(map[ast.Node]Object),
1070 }
1071 name := mustTypecheck(test.src, nil, &info).Name()
1072
1073 // the test cases expect at most one Implicits entry
1074 if len(info.Implicits) > 1 {
1075 t.Errorf("package %s: %d Implicits entries found", name, len(info.Implicits))
1076 continue
1077 }
1078
1079 // extract Implicits entry, if any
1080 var got string
1081 for n, obj := range info.Implicits {
1082 switch x := n.(type) {
1083 case *ast.ImportSpec:
1084 got = "importSpec"
1085 case *ast.CaseClause:
1086 got = "caseClause"
1087 case *ast.Field:
1088 got = "field"
1089 default:
1090 t.Fatalf("package %s: unexpected %T", name, x)
1091 }
1092 got += ": " + obj.String()
1093 }
1094
1095 // verify entry
1096 if got != test.want {
1097 t.Errorf("package %s: got %q; want %q", name, got, test.want)
1098 }
1099 }
1100 }
1101
1102 func TestPkgNameOf(t *testing.T) {
1103 testenv.MustHaveGoBuild(t)
1104
1105 const src = `
1106 package p
1107
1108 import (
1109 . "os"
1110 _ "io"
1111 "math"
1112 "path/filepath"
1113 snort "sort"
1114 )
1115
1116 // avoid imported and not used errors
1117 var (
1118 _ = Open // os.Open
1119 _ = math.Sin
1120 _ = filepath.Abs
1121 _ = snort.Ints
1122 )
1123 `
1124
1125 var tests = []struct {
1126 path string // path string enclosed in "'s
1127 want string
1128 }{
1129 {`"os"`, "."},
1130 {`"io"`, "_"},
1131 {`"math"`, "math"},
1132 {`"path/filepath"`, "filepath"},
1133 {`"sort"`, "snort"},
1134 }
1135
1136 fset := token.NewFileSet()
1137 f := mustParse(fset, src)
1138 info := Info{
1139 Defs: make(map[*ast.Ident]Object),
1140 Implicits: make(map[ast.Node]Object),
1141 }
1142 var conf Config
1143 conf.Importer = defaultImporter(fset)
1144 _, err := conf.Check("p", fset, []*ast.File{f}, &info)
1145 if err != nil {
1146 t.Fatal(err)
1147 }
1148
1149 // map import paths to importDecl
1150 imports := make(map[string]*ast.ImportSpec)
1151 for _, s := range f.Decls[0].(*ast.GenDecl).Specs {
1152 if imp, _ := s.(*ast.ImportSpec); imp != nil {
1153 imports[imp.Path.Value] = imp
1154 }
1155 }
1156
1157 for _, test := range tests {
1158 imp := imports[test.path]
1159 if imp == nil {
1160 t.Fatalf("invalid test case: import path %s not found", test.path)
1161 }
1162 got := info.PkgNameOf(imp)
1163 if got == nil {
1164 t.Fatalf("import %s: package name not found", test.path)
1165 }
1166 if got.Name() != test.want {
1167 t.Errorf("import %s: got %s; want %s", test.path, got.Name(), test.want)
1168 }
1169 }
1170
1171 // test non-existing importDecl
1172 if got := info.PkgNameOf(new(ast.ImportSpec)); got != nil {
1173 t.Errorf("got %s for non-existing import declaration", got.Name())
1174 }
1175 }
1176
1177 func predString(tv TypeAndValue) string {
1178 var buf strings.Builder
1179 pred := func(b bool, s string) {
1180 if b {
1181 if buf.Len() > 0 {
1182 buf.WriteString(", ")
1183 }
1184 buf.WriteString(s)
1185 }
1186 }
1187
1188 pred(tv.IsVoid(), "void")
1189 pred(tv.IsType(), "type")
1190 pred(tv.IsBuiltin(), "builtin")
1191 pred(tv.IsValue() && tv.Value != nil, "const")
1192 pred(tv.IsValue() && tv.Value == nil, "value")
1193 pred(tv.IsNil(), "nil")
1194 pred(tv.Addressable(), "addressable")
1195 pred(tv.Assignable(), "assignable")
1196 pred(tv.HasOk(), "hasOk")
1197
1198 if buf.Len() == 0 {
1199 return "invalid"
1200 }
1201 return buf.String()
1202 }
1203
1204 func TestPredicatesInfo(t *testing.T) {
1205 testenv.MustHaveGoBuild(t)
1206
1207 var tests = []struct {
1208 src string
1209 expr string
1210 pred string
1211 }{
1212 // void
1213 {`package n0; func f() { f() }`, `f()`, `void`},
1214
1215 // types
1216 {`package t0; type _ int`, `int`, `type`},
1217 {`package t1; type _ []int`, `[]int`, `type`},
1218 {`package t2; type _ func()`, `func()`, `type`},
1219 {`package t3; type _ func(int)`, `int`, `type`},
1220 {`package t3; type _ func(...int)`, `...int`, `type`},
1221
1222 // built-ins
1223 {`package b0; var _ = len("")`, `len`, `builtin`},
1224 {`package b1; var _ = (len)("")`, `(len)`, `builtin`},
1225
1226 // constants
1227 {`package c0; var _ = 42`, `42`, `const`},
1228 {`package c1; var _ = "foo" + "bar"`, `"foo" + "bar"`, `const`},
1229 {`package c2; const (i = 1i; _ = i)`, `i`, `const`},
1230
1231 // values
1232 {`package v0; var (a, b int; _ = a + b)`, `a + b`, `value`},
1233 {`package v1; var _ = &[]int{1}`, `[]int{…}`, `value`},
1234 {`package v2; var _ = func(){}`, `(func() literal)`, `value`},
1235 {`package v4; func f() { _ = f }`, `f`, `value`},
1236 {`package v3; var _ *int = nil`, `nil`, `value, nil`},
1237 {`package v3; var _ *int = (nil)`, `(nil)`, `value, nil`},
1238
1239 // addressable (and thus assignable) operands
1240 {`package a0; var (x int; _ = x)`, `x`, `value, addressable, assignable`},
1241 {`package a1; var (p *int; _ = *p)`, `*p`, `value, addressable, assignable`},
1242 {`package a2; var (s []int; _ = s[0])`, `s[0]`, `value, addressable, assignable`},
1243 {`package a3; var (s struct{f int}; _ = s.f)`, `s.f`, `value, addressable, assignable`},
1244 {`package a4; var (a [10]int; _ = a[0])`, `a[0]`, `value, addressable, assignable`},
1245 {`package a5; func _(x int) { _ = x }`, `x`, `value, addressable, assignable`},
1246 {`package a6; func _()(x int) { _ = x; return }`, `x`, `value, addressable, assignable`},
1247 {`package a7; type T int; func (x T) _() { _ = x }`, `x`, `value, addressable, assignable`},
1248 // composite literals are not addressable
1249
1250 // assignable but not addressable values
1251 {`package s0; var (m map[int]int; _ = m[0])`, `m[0]`, `value, assignable, hasOk`},
1252 {`package s1; var (m map[int]int; _, _ = m[0])`, `m[0]`, `value, assignable, hasOk`},
1253
1254 // hasOk expressions
1255 {`package k0; var (ch chan int; _ = <-ch)`, `<-ch`, `value, hasOk`},
1256 {`package k1; var (ch chan int; _, _ = <-ch)`, `<-ch`, `value, hasOk`},
1257
1258 // missing entries
1259 // - package names are collected in the Uses map
1260 // - identifiers being declared are collected in the Defs map
1261 {`package m0; import "os"; func _() { _ = os.Stdout }`, `os`, `<missing>`},
1262 {`package m1; import p "os"; func _() { _ = p.Stdout }`, `p`, `<missing>`},
1263 {`package m2; const c = 0`, `c`, `<missing>`},
1264 {`package m3; type T int`, `T`, `<missing>`},
1265 {`package m4; var v int`, `v`, `<missing>`},
1266 {`package m5; func f() {}`, `f`, `<missing>`},
1267 {`package m6; func _(x int) {}`, `x`, `<missing>`},
1268 {`package m6; func _()(x int) { return }`, `x`, `<missing>`},
1269 {`package m6; type T int; func (x T) _() {}`, `x`, `<missing>`},
1270 }
1271
1272 for _, test := range tests {
1273 info := Info{Types: make(map[ast.Expr]TypeAndValue)}
1274 name := mustTypecheck(test.src, nil, &info).Name()
1275
1276 // look for expression predicates
1277 got := "<missing>"
1278 for e, tv := range info.Types {
1279 //println(name, ExprString(e))
1280 if ExprString(e) == test.expr {
1281 got = predString(tv)
1282 break
1283 }
1284 }
1285
1286 if got != test.pred {
1287 t.Errorf("package %s: got %s; want %s", name, got, test.pred)
1288 }
1289 }
1290 }
1291
1292 func TestScopesInfo(t *testing.T) {
1293 testenv.MustHaveGoBuild(t)
1294
1295 var tests = []struct {
1296 src string
1297 scopes []string // list of scope descriptors of the form kind:varlist
1298 }{
1299 {`package p0`, []string{
1300 "file:",
1301 }},
1302 {`package p1; import ( "fmt"; m "math"; _ "os" ); var ( _ = fmt.Println; _ = m.Pi )`, []string{
1303 "file:fmt m",
1304 }},
1305 {`package p2; func _() {}`, []string{
1306 "file:", "func:",
1307 }},
1308 {`package p3; func _(x, y int) {}`, []string{
1309 "file:", "func:x y",
1310 }},
1311 {`package p4; func _(x, y int) { x, z := 1, 2; _ = z }`, []string{
1312 "file:", "func:x y z", // redeclaration of x
1313 }},
1314 {`package p5; func _(x, y int) (u, _ int) { return }`, []string{
1315 "file:", "func:u x y",
1316 }},
1317 {`package p6; func _() { { var x int; _ = x } }`, []string{
1318 "file:", "func:", "block:x",
1319 }},
1320 {`package p7; func _() { if true {} }`, []string{
1321 "file:", "func:", "if:", "block:",
1322 }},
1323 {`package p8; func _() { if x := 0; x < 0 { y := x; _ = y } }`, []string{
1324 "file:", "func:", "if:x", "block:y",
1325 }},
1326 {`package p9; func _() { switch x := 0; x {} }`, []string{
1327 "file:", "func:", "switch:x",
1328 }},
1329 {`package p10; func _() { switch x := 0; x { case 1: y := x; _ = y; default: }}`, []string{
1330 "file:", "func:", "switch:x", "case:y", "case:",
1331 }},
1332 {`package p11; func _(t interface{}) { switch t.(type) {} }`, []string{
1333 "file:", "func:t", "type switch:",
1334 }},
1335 {`package p12; func _(t interface{}) { switch t := t; t.(type) {} }`, []string{
1336 "file:", "func:t", "type switch:t",
1337 }},
1338 {`package p13; func _(t interface{}) { switch x := t.(type) { case int: _ = x } }`, []string{
1339 "file:", "func:t", "type switch:", "case:x", // x implicitly declared
1340 }},
1341 {`package p14; func _() { select{} }`, []string{
1342 "file:", "func:",
1343 }},
1344 {`package p15; func _(c chan int) { select{ case <-c: } }`, []string{
1345 "file:", "func:c", "comm:",
1346 }},
1347 {`package p16; func _(c chan int) { select{ case i := <-c: x := i; _ = x} }`, []string{
1348 "file:", "func:c", "comm:i x",
1349 }},
1350 {`package p17; func _() { for{} }`, []string{
1351 "file:", "func:", "for:", "block:",
1352 }},
1353 {`package p18; func _(n int) { for i := 0; i < n; i++ { _ = i } }`, []string{
1354 "file:", "func:n", "for:i", "block:",
1355 }},
1356 {`package p19; func _(a []int) { for i := range a { _ = i} }`, []string{
1357 "file:", "func:a", "range:i", "block:",
1358 }},
1359 {`package p20; var s int; func _(a []int) { for i, x := range a { s += x; _ = i } }`, []string{
1360 "file:", "func:a", "range:i x", "block:",
1361 }},
1362 }
1363
1364 for _, test := range tests {
1365 info := Info{Scopes: make(map[ast.Node]*Scope)}
1366 name := mustTypecheck(test.src, nil, &info).Name()
1367
1368 // number of scopes must match
1369 if len(info.Scopes) != len(test.scopes) {
1370 t.Errorf("package %s: got %d scopes; want %d", name, len(info.Scopes), len(test.scopes))
1371 }
1372
1373 // scope descriptions must match
1374 for node, scope := range info.Scopes {
1375 kind := "<unknown node kind>"
1376 switch node.(type) {
1377 case *ast.File:
1378 kind = "file"
1379 case *ast.FuncType:
1380 kind = "func"
1381 case *ast.BlockStmt:
1382 kind = "block"
1383 case *ast.IfStmt:
1384 kind = "if"
1385 case *ast.SwitchStmt:
1386 kind = "switch"
1387 case *ast.TypeSwitchStmt:
1388 kind = "type switch"
1389 case *ast.CaseClause:
1390 kind = "case"
1391 case *ast.CommClause:
1392 kind = "comm"
1393 case *ast.ForStmt:
1394 kind = "for"
1395 case *ast.RangeStmt:
1396 kind = "range"
1397 }
1398
1399 // look for matching scope description
1400 desc := kind + ":" + strings.Join(scope.Names(), " ")
1401 if !slices.Contains(test.scopes, desc) {
1402 t.Errorf("package %s: no matching scope found for %s", name, desc)
1403 }
1404 }
1405 }
1406 }
1407
1408 func TestInitOrderInfo(t *testing.T) {
1409 var tests = []struct {
1410 src string
1411 inits []string
1412 }{
1413 {`package p0; var (x = 1; y = x)`, []string{
1414 "x = 1", "y = x",
1415 }},
1416 {`package p1; var (a = 1; b = 2; c = 3)`, []string{
1417 "a = 1", "b = 2", "c = 3",
1418 }},
1419 {`package p2; var (a, b, c = 1, 2, 3)`, []string{
1420 "a = 1", "b = 2", "c = 3",
1421 }},
1422 {`package p3; var _ = f(); func f() int { return 1 }`, []string{
1423 "_ = f()", // blank var
1424 }},
1425 {`package p4; var (a = 0; x = y; y = z; z = 0)`, []string{
1426 "a = 0", "z = 0", "y = z", "x = y",
1427 }},
1428 {`package p5; var (a, _ = m[0]; m map[int]string)`, []string{
1429 "a, _ = m[0]", // blank var
1430 }},
1431 {`package p6; var a, b = f(); func f() (_, _ int) { return z, z }; var z = 0`, []string{
1432 "z = 0", "a, b = f()",
1433 }},
1434 {`package p7; var (a = func() int { return b }(); b = 1)`, []string{
1435 "b = 1", "a = (func() int literal)()",
1436 }},
1437 {`package p8; var (a, b = func() (_, _ int) { return c, c }(); c = 1)`, []string{
1438 "c = 1", "a, b = (func() (_, _ int) literal)()",
1439 }},
1440 {`package p9; type T struct{}; func (T) m() int { _ = y; return 0 }; var x, y = T.m, 1`, []string{
1441 "y = 1", "x = T.m",
1442 }},
1443 {`package p10; var (d = c + b; a = 0; b = 0; c = 0)`, []string{
1444 "a = 0", "b = 0", "c = 0", "d = c + b",
1445 }},
1446 {`package p11; var (a = e + c; b = d + c; c = 0; d = 0; e = 0)`, []string{
1447 "c = 0", "d = 0", "b = d + c", "e = 0", "a = e + c",
1448 }},
1449 // emit an initializer for n:1 initializations only once (not for each node
1450 // on the lhs which may appear in different order in the dependency graph)
1451 {`package p12; var (a = x; b = 0; x, y = m[0]; m map[int]int)`, []string{
1452 "b = 0", "x, y = m[0]", "a = x",
1453 }},
1454 // test case from spec section on package initialization
1455 {`package p12
1456
1457 var (
1458 a = c + b
1459 b = f()
1460 c = f()
1461 d = 3
1462 )
1463
1464 func f() int {
1465 d++
1466 return d
1467 }`, []string{
1468 "d = 3", "b = f()", "c = f()", "a = c + b",
1469 }},
1470 // test case for go.dev/issue/7131
1471 {`package main
1472
1473 var counter int
1474 func next() int { counter++; return counter }
1475
1476 var _ = makeOrder()
1477 func makeOrder() []int { return []int{f, b, d, e, c, a} }
1478
1479 var a = next()
1480 var b, c = next(), next()
1481 var d, e, f = next(), next(), next()
1482 `, []string{
1483 "a = next()", "b = next()", "c = next()", "d = next()", "e = next()", "f = next()", "_ = makeOrder()",
1484 }},
1485 // test case for go.dev/issue/10709
1486 {`package p13
1487
1488 var (
1489 v = t.m()
1490 t = makeT(0)
1491 )
1492
1493 type T struct{}
1494
1495 func (T) m() int { return 0 }
1496
1497 func makeT(n int) T {
1498 if n > 0 {
1499 return makeT(n-1)
1500 }
1501 return T{}
1502 }`, []string{
1503 "t = makeT(0)", "v = t.m()",
1504 }},
1505 // test case for go.dev/issue/10709: same as test before, but variable decls swapped
1506 {`package p14
1507
1508 var (
1509 t = makeT(0)
1510 v = t.m()
1511 )
1512
1513 type T struct{}
1514
1515 func (T) m() int { return 0 }
1516
1517 func makeT(n int) T {
1518 if n > 0 {
1519 return makeT(n-1)
1520 }
1521 return T{}
1522 }`, []string{
1523 "t = makeT(0)", "v = t.m()",
1524 }},
1525 // another candidate possibly causing problems with go.dev/issue/10709
1526 {`package p15
1527
1528 var y1 = f1()
1529
1530 func f1() int { return g1() }
1531 func g1() int { f1(); return x1 }
1532
1533 var x1 = 0
1534
1535 var y2 = f2()
1536
1537 func f2() int { return g2() }
1538 func g2() int { return x2 }
1539
1540 var x2 = 0`, []string{
1541 "x1 = 0", "y1 = f1()", "x2 = 0", "y2 = f2()",
1542 }},
1543 }
1544
1545 for _, test := range tests {
1546 info := Info{}
1547 name := mustTypecheck(test.src, nil, &info).Name()
1548
1549 // number of initializers must match
1550 if len(info.InitOrder) != len(test.inits) {
1551 t.Errorf("package %s: got %d initializers; want %d", name, len(info.InitOrder), len(test.inits))
1552 continue
1553 }
1554
1555 // initializers must match
1556 for i, want := range test.inits {
1557 got := info.InitOrder[i].String()
1558 if got != want {
1559 t.Errorf("package %s, init %d: got %s; want %s", name, i, got, want)
1560 continue
1561 }
1562 }
1563 }
1564 }
1565
1566 func TestMultiFileInitOrder(t *testing.T) {
1567 fset := token.NewFileSet()
1568 fileA := mustParse(fset, `package main; var a = 1`)
1569 fileB := mustParse(fset, `package main; var b = 2`)
1570
1571 // The initialization order must not depend on the parse
1572 // order of the files, only on the presentation order to
1573 // the type-checker.
1574 for _, test := range []struct {
1575 files []*ast.File
1576 want string
1577 }{
1578 {[]*ast.File{fileA, fileB}, "[a = 1 b = 2]"},
1579 {[]*ast.File{fileB, fileA}, "[b = 2 a = 1]"},
1580 } {
1581 var info Info
1582 if _, err := new(Config).Check("main", fset, test.files, &info); err != nil {
1583 t.Fatal(err)
1584 }
1585 if got := fmt.Sprint(info.InitOrder); got != test.want {
1586 t.Fatalf("got %s; want %s", got, test.want)
1587 }
1588 }
1589 }
1590
1591 func TestFiles(t *testing.T) {
1592 var sources = []string{
1593 "package p; type T struct{}; func (T) m1() {}",
1594 "package p; func (T) m2() {}; var x interface{ m1(); m2() } = T{}",
1595 "package p; func (T) m3() {}; var y interface{ m1(); m2(); m3() } = T{}",
1596 "package p",
1597 }
1598
1599 var conf Config
1600 fset := token.NewFileSet()
1601 pkg := NewPackage("p", "p")
1602 var info Info
1603 check := NewChecker(&conf, fset, pkg, &info)
1604
1605 for _, src := range sources {
1606 if err := check.Files([]*ast.File{mustParse(fset, src)}); err != nil {
1607 t.Error(err)
1608 }
1609 }
1610
1611 // check InitOrder is [x y]
1612 var vars []string
1613 for _, init := range info.InitOrder {
1614 for _, v := range init.Lhs {
1615 vars = append(vars, v.Name())
1616 }
1617 }
1618 if got, want := fmt.Sprint(vars), "[x y]"; got != want {
1619 t.Errorf("InitOrder == %s, want %s", got, want)
1620 }
1621 }
1622
1623 type testImporter map[string]*Package
1624
1625 func (m testImporter) Import(path string) (*Package, error) {
1626 if pkg := m[path]; pkg != nil {
1627 return pkg, nil
1628 }
1629 return nil, fmt.Errorf("package %q not found", path)
1630 }
1631
1632 func TestSelection(t *testing.T) {
1633 selections := make(map[*ast.SelectorExpr]*Selection)
1634
1635 // We need a specific fileset in this test below for positions.
1636 // Cannot use typecheck helper.
1637 fset := token.NewFileSet()
1638 imports := make(testImporter)
1639 conf := Config{Importer: imports}
1640 makePkg := func(path, src string) {
1641 pkg, err := conf.Check(path, fset, []*ast.File{mustParse(fset, src)}, &Info{Selections: selections})
1642 if err != nil {
1643 t.Fatal(err)
1644 }
1645 imports[path] = pkg
1646 }
1647
1648 const libSrc = `
1649 package lib
1650 type T float64
1651 const C T = 3
1652 var V T
1653 func F() {}
1654 func (T) M() {}
1655 `
1656 const mainSrc = `
1657 package main
1658 import "lib"
1659
1660 type A struct {
1661 *B
1662 C
1663 }
1664
1665 type B struct {
1666 b int
1667 }
1668
1669 func (B) f(int)
1670
1671 type C struct {
1672 c int
1673 }
1674
1675 type G[P any] struct {
1676 p P
1677 }
1678
1679 func (G[P]) m(P) {}
1680
1681 var Inst G[int]
1682
1683 func (C) g()
1684 func (*C) h()
1685
1686 func main() {
1687 // qualified identifiers
1688 var _ lib.T
1689 _ = lib.C
1690 _ = lib.F
1691 _ = lib.V
1692 _ = lib.T.M
1693
1694 // fields
1695 _ = A{}.B
1696 _ = new(A).B
1697
1698 _ = A{}.C
1699 _ = new(A).C
1700
1701 _ = A{}.b
1702 _ = new(A).b
1703
1704 _ = A{}.c
1705 _ = new(A).c
1706
1707 _ = Inst.p
1708 _ = G[string]{}.p
1709
1710 // methods
1711 _ = A{}.f
1712 _ = new(A).f
1713 _ = A{}.g
1714 _ = new(A).g
1715 _ = new(A).h
1716
1717 _ = B{}.f
1718 _ = new(B).f
1719
1720 _ = C{}.g
1721 _ = new(C).g
1722 _ = new(C).h
1723 _ = Inst.m
1724
1725 // method expressions
1726 _ = A.f
1727 _ = (*A).f
1728 _ = B.f
1729 _ = (*B).f
1730 _ = G[string].m
1731 }`
1732
1733 wantOut := map[string][2]string{
1734 "lib.T.M": {"method expr (lib.T) M(lib.T)", ".[0]"},
1735
1736 "A{}.B": {"field (main.A) B *main.B", ".[0]"},
1737 "new(A).B": {"field (*main.A) B *main.B", "->[0]"},
1738 "A{}.C": {"field (main.A) C main.C", ".[1]"},
1739 "new(A).C": {"field (*main.A) C main.C", "->[1]"},
1740 "A{}.b": {"field (main.A) b int", "->[0 0]"},
1741 "new(A).b": {"field (*main.A) b int", "->[0 0]"},
1742 "A{}.c": {"field (main.A) c int", ".[1 0]"},
1743 "new(A).c": {"field (*main.A) c int", "->[1 0]"},
1744 "Inst.p": {"field (main.G[int]) p int", ".[0]"},
1745
1746 "A{}.f": {"method (main.A) f(int)", "->[0 0]"},
1747 "new(A).f": {"method (*main.A) f(int)", "->[0 0]"},
1748 "A{}.g": {"method (main.A) g()", ".[1 0]"},
1749 "new(A).g": {"method (*main.A) g()", "->[1 0]"},
1750 "new(A).h": {"method (*main.A) h()", "->[1 1]"}, // TODO(gri) should this report .[1 1] ?
1751 "B{}.f": {"method (main.B) f(int)", ".[0]"},
1752 "new(B).f": {"method (*main.B) f(int)", "->[0]"},
1753 "C{}.g": {"method (main.C) g()", ".[0]"},
1754 "new(C).g": {"method (*main.C) g()", "->[0]"},
1755 "new(C).h": {"method (*main.C) h()", "->[1]"}, // TODO(gri) should this report .[1] ?
1756 "Inst.m": {"method (main.G[int]) m(int)", ".[0]"},
1757
1758 "A.f": {"method expr (main.A) f(main.A, int)", "->[0 0]"},
1759 "(*A).f": {"method expr (*main.A) f(*main.A, int)", "->[0 0]"},
1760 "B.f": {"method expr (main.B) f(main.B, int)", ".[0]"},
1761 "(*B).f": {"method expr (*main.B) f(*main.B, int)", "->[0]"},
1762 "G[string].m": {"method expr (main.G[string]) m(main.G[string], string)", ".[0]"},
1763 "G[string]{}.p": {"field (main.G[string]) p string", ".[0]"},
1764 }
1765
1766 makePkg("lib", libSrc)
1767 makePkg("main", mainSrc)
1768
1769 for e, sel := range selections {
1770 _ = sel.String() // assertion: must not panic
1771
1772 start := fset.Position(e.Pos()).Offset
1773 end := fset.Position(e.End()).Offset
1774 syntax := mainSrc[start:end] // (all SelectorExprs are in main, not lib)
1775
1776 direct := "."
1777 if sel.Indirect() {
1778 direct = "->"
1779 }
1780 got := [2]string{
1781 sel.String(),
1782 fmt.Sprintf("%s%v", direct, sel.Index()),
1783 }
1784 want := wantOut[syntax]
1785 if want != got {
1786 t.Errorf("%s: got %q; want %q", syntax, got, want)
1787 }
1788 delete(wantOut, syntax)
1789
1790 // We must explicitly assert properties of the
1791 // Signature's receiver since it doesn't participate
1792 // in Identical() or String().
1793 sig, _ := sel.Type().(*Signature)
1794 if sel.Kind() == MethodVal {
1795 got := sig.Recv().Type()
1796 want := sel.Recv()
1797 if !Identical(got, want) {
1798 t.Errorf("%s: Recv() = %s, want %s", syntax, got, want)
1799 }
1800 } else if sig != nil && sig.Recv() != nil {
1801 t.Errorf("%s: signature has receiver %s", sig, sig.Recv().Type())
1802 }
1803 }
1804 // Assert that all wantOut entries were used exactly once.
1805 for syntax := range wantOut {
1806 t.Errorf("no ast.Selection found with syntax %q", syntax)
1807 }
1808 }
1809
1810 func TestIssue8518(t *testing.T) {
1811 fset := token.NewFileSet()
1812 imports := make(testImporter)
1813 conf := Config{
1814 Error: func(err error) { t.Log(err) }, // don't exit after first error
1815 Importer: imports,
1816 }
1817 makePkg := func(path, src string) {
1818 imports[path], _ = conf.Check(path, fset, []*ast.File{mustParse(fset, src)}, nil) // errors logged via conf.Error
1819 }
1820
1821 const libSrc = `
1822 package a
1823 import "missing"
1824 const C1 = foo
1825 const C2 = missing.C
1826 `
1827
1828 const mainSrc = `
1829 package main
1830 import "a"
1831 var _ = a.C1
1832 var _ = a.C2
1833 `
1834
1835 makePkg("a", libSrc)
1836 makePkg("main", mainSrc) // don't crash when type-checking this package
1837 }
1838
1839 func TestIssue59603(t *testing.T) {
1840 fset := token.NewFileSet()
1841 imports := make(testImporter)
1842 conf := Config{
1843 Error: func(err error) { t.Log(err) }, // don't exit after first error
1844 Importer: imports,
1845 }
1846 makePkg := func(path, src string) {
1847 imports[path], _ = conf.Check(path, fset, []*ast.File{mustParse(fset, src)}, nil) // errors logged via conf.Error
1848 }
1849
1850 const libSrc = `
1851 package a
1852 const C = foo
1853 `
1854
1855 const mainSrc = `
1856 package main
1857 import "a"
1858 const _ = a.C
1859 `
1860
1861 makePkg("a", libSrc)
1862 makePkg("main", mainSrc) // don't crash when type-checking this package
1863 }
1864
1865 func TestLookupFieldOrMethodOnNil(t *testing.T) {
1866 // LookupFieldOrMethod on a nil type is expected to produce a run-time panic.
1867 defer func() {
1868 const want = "LookupFieldOrMethod on nil type"
1869 p := recover()
1870 if s, ok := p.(string); !ok || s != want {
1871 t.Fatalf("got %v, want %s", p, want)
1872 }
1873 }()
1874 LookupFieldOrMethod(nil, false, nil, "")
1875 }
1876
1877 func TestLookupFieldOrMethod(t *testing.T) {
1878 // Test cases assume a lookup of the form a.f or x.f, where a stands for an
1879 // addressable value, and x for a non-addressable value (even though a variable
1880 // for ease of test case writing).
1881 //
1882 // Should be kept in sync with TestMethodSet.
1883 var tests = []struct {
1884 src string
1885 found bool
1886 index []int
1887 indirect bool
1888 }{
1889 // field lookups
1890 {"var x T; type T struct{}", false, nil, false},
1891 {"var x T; type T struct{ f int }", true, []int{0}, false},
1892 {"var x T; type T struct{ a, b, f, c int }", true, []int{2}, false},
1893
1894 // field lookups on a generic type
1895 {"var x T[int]; type T[P any] struct{}", false, nil, false},
1896 {"var x T[int]; type T[P any] struct{ f P }", true, []int{0}, false},
1897 {"var x T[int]; type T[P any] struct{ a, b, f, c P }", true, []int{2}, false},
1898
1899 // method lookups
1900 {"var a T; type T struct{}; func (T) f() {}", true, []int{0}, false},
1901 {"var a *T; type T struct{}; func (T) f() {}", true, []int{0}, true},
1902 {"var a T; type T struct{}; func (*T) f() {}", true, []int{0}, false},
1903 {"var a *T; type T struct{}; func (*T) f() {}", true, []int{0}, true}, // TODO(gri) should this report indirect = false?
1904
1905 // method lookups on a generic type
1906 {"var a T[int]; type T[P any] struct{}; func (T[P]) f() {}", true, []int{0}, false},
1907 {"var a *T[int]; type T[P any] struct{}; func (T[P]) f() {}", true, []int{0}, true},
1908 {"var a T[int]; type T[P any] struct{}; func (*T[P]) f() {}", true, []int{0}, false},
1909 {"var a *T[int]; type T[P any] struct{}; func (*T[P]) f() {}", true, []int{0}, true}, // TODO(gri) should this report indirect = false?
1910
1911 // collisions
1912 {"type ( E1 struct{ f int }; E2 struct{ f int }; x struct{ E1; *E2 })", false, []int{1, 0}, false},
1913 {"type ( E1 struct{ f int }; E2 struct{}; x struct{ E1; *E2 }); func (E2) f() {}", false, []int{1, 0}, false},
1914
1915 // collisions on a generic type
1916 {"type ( E1[P any] struct{ f P }; E2[P any] struct{ f P }; x struct{ E1[int]; *E2[int] })", false, []int{1, 0}, false},
1917 {"type ( E1[P any] struct{ f P }; E2[P any] struct{}; x struct{ E1[int]; *E2[int] }); func (E2[P]) f() {}", false, []int{1, 0}, false},
1918
1919 // outside methodset
1920 // (*T).f method exists, but value of type T is not addressable
1921 {"var x T; type T struct{}; func (*T) f() {}", false, nil, true},
1922
1923 // outside method set of a generic type
1924 {"var x T[int]; type T[P any] struct{}; func (*T[P]) f() {}", false, nil, true},
1925
1926 // recursive generic types; see go.dev/issue/52715
1927 {"var a T[int]; type ( T[P any] struct { *N[P] }; N[P any] struct { *T[P] } ); func (N[P]) f() {}", true, []int{0, 0}, true},
1928 {"var a T[int]; type ( T[P any] struct { *N[P] }; N[P any] struct { *T[P] } ); func (T[P]) f() {}", true, []int{0}, false},
1929 }
1930
1931 for _, test := range tests {
1932 pkg := mustTypecheck("package p;"+test.src, nil, nil)
1933
1934 obj := pkg.Scope().Lookup("a")
1935 if obj == nil {
1936 if obj = pkg.Scope().Lookup("x"); obj == nil {
1937 t.Errorf("%s: incorrect test case - no object a or x", test.src)
1938 continue
1939 }
1940 }
1941
1942 f, index, indirect := LookupFieldOrMethod(obj.Type(), obj.Name() == "a", pkg, "f")
1943 if (f != nil) != test.found {
1944 if f == nil {
1945 t.Errorf("%s: got no object; want one", test.src)
1946 } else {
1947 t.Errorf("%s: got object = %v; want none", test.src, f)
1948 }
1949 }
1950 if !slices.Equal(index, test.index) {
1951 t.Errorf("%s: got index = %v; want %v", test.src, index, test.index)
1952 }
1953 if indirect != test.indirect {
1954 t.Errorf("%s: got indirect = %v; want %v", test.src, indirect, test.indirect)
1955 }
1956 }
1957 }
1958
1959 // Test for go.dev/issue/52715
1960 func TestLookupFieldOrMethod_RecursiveGeneric(t *testing.T) {
1961 const src = `
1962 package pkg
1963
1964 type Tree[T any] struct {
1965 *Node[T]
1966 }
1967
1968 func (*Tree[R]) N(r R) R { return r }
1969
1970 type Node[T any] struct {
1971 *Tree[T]
1972 }
1973
1974 type Instance = *Tree[int]
1975 `
1976
1977 fset := token.NewFileSet()
1978 f := mustParse(fset, src)
1979 pkg := NewPackage("pkg", f.Name.Name)
1980 if err := NewChecker(nil, fset, pkg, nil).Files([]*ast.File{f}); err != nil {
1981 panic(err)
1982 }
1983
1984 T := pkg.Scope().Lookup("Instance").Type()
1985 _, _, _ = LookupFieldOrMethod(T, false, pkg, "M") // verify that LookupFieldOrMethod terminates
1986 }
1987
1988 // newDefined creates a new defined type named T with the given underlying type.
1989 // Helper function for use with TestIncompleteInterfaces only.
1990 func newDefined(underlying Type) *Named {
1991 tname := NewTypeName(nopos, nil, "T", nil)
1992 return NewNamed(tname, underlying, nil)
1993 }
1994
1995 func TestConvertibleTo(t *testing.T) {
1996 for _, test := range []struct {
1997 v, t Type
1998 want bool
1999 }{
2000 {Typ[Int], Typ[Int], true},
2001 {Typ[Int], Typ[Float32], true},
2002 {Typ[Int], Typ[String], true},
2003 {newDefined(Typ[Int]), Typ[Int], true},
2004 {newDefined(new(Struct)), new(Struct), true},
2005 {newDefined(Typ[Int]), new(Struct), false},
2006 {Typ[UntypedInt], Typ[Int], true},
2007 {NewSlice(Typ[Int]), NewArray(Typ[Int], 10), true},
2008 {NewSlice(Typ[Int]), NewArray(Typ[Uint], 10), false},
2009 {NewSlice(Typ[Int]), NewPointer(NewArray(Typ[Int], 10)), true},
2010 {NewSlice(Typ[Int]), NewPointer(NewArray(Typ[Uint], 10)), false},
2011 // Untyped string values are not permitted by the spec, so the behavior below is undefined.
2012 {Typ[UntypedString], Typ[String], true},
2013 } {
2014 if got := ConvertibleTo(test.v, test.t); got != test.want {
2015 t.Errorf("ConvertibleTo(%v, %v) = %t, want %t", test.v, test.t, got, test.want)
2016 }
2017 }
2018 }
2019
2020 func TestAssignableTo(t *testing.T) {
2021 for _, test := range []struct {
2022 v, t Type
2023 want bool
2024 }{
2025 {Typ[Int], Typ[Int], true},
2026 {Typ[Int], Typ[Float32], false},
2027 {newDefined(Typ[Int]), Typ[Int], false},
2028 {newDefined(new(Struct)), new(Struct), true},
2029 {Typ[UntypedBool], Typ[Bool], true},
2030 {Typ[UntypedString], Typ[Bool], false},
2031 // Neither untyped string nor untyped numeric assignments arise during
2032 // normal type checking, so the below behavior is technically undefined by
2033 // the spec.
2034 {Typ[UntypedString], Typ[String], true},
2035 {Typ[UntypedInt], Typ[Int], true},
2036 } {
2037 if got := AssignableTo(test.v, test.t); got != test.want {
2038 t.Errorf("AssignableTo(%v, %v) = %t, want %t", test.v, test.t, got, test.want)
2039 }
2040 }
2041 }
2042
2043 func TestIdentical(t *testing.T) {
2044 // For each test, we compare the types of objects X and Y in the source.
2045 tests := []struct {
2046 src string
2047 want bool
2048 }{
2049 // Basic types.
2050 {"var X int; var Y int", true},
2051 {"var X int; var Y string", false},
2052
2053 // TODO: add more tests for complex types.
2054
2055 // Named types.
2056 {"type X int; type Y int", false},
2057
2058 // Aliases.
2059 {"type X = int; type Y = int", true},
2060
2061 // Functions.
2062 {`func X(int) string { return "" }; func Y(int) string { return "" }`, true},
2063 {`func X() string { return "" }; func Y(int) string { return "" }`, false},
2064 {`func X(int) string { return "" }; func Y(int) {}`, false},
2065
2066 // Generic functions. Type parameters should be considered identical modulo
2067 // renaming. See also go.dev/issue/49722.
2068 {`func X[P ~int](){}; func Y[Q ~int]() {}`, true},
2069 {`func X[P1 any, P2 ~*P1](){}; func Y[Q1 any, Q2 ~*Q1]() {}`, true},
2070 {`func X[P1 any, P2 ~[]P1](){}; func Y[Q1 any, Q2 ~*Q1]() {}`, false},
2071 {`func X[P ~int](P){}; func Y[Q ~int](Q) {}`, true},
2072 {`func X[P ~string](P){}; func Y[Q ~int](Q) {}`, false},
2073 {`func X[P ~int]([]P){}; func Y[Q ~int]([]Q) {}`, true},
2074 }
2075
2076 for _, test := range tests {
2077 pkg := mustTypecheck("package p;"+test.src, nil, nil)
2078 X := pkg.Scope().Lookup("X")
2079 Y := pkg.Scope().Lookup("Y")
2080 if X == nil || Y == nil {
2081 t.Fatal("test must declare both X and Y")
2082 }
2083 if got := Identical(X.Type(), Y.Type()); got != test.want {
2084 t.Errorf("Identical(%s, %s) = %t, want %t", X.Type(), Y.Type(), got, test.want)
2085 }
2086 }
2087 }
2088
2089 func TestIdentical_issue15173(t *testing.T) {
2090 // Identical should allow nil arguments and be symmetric.
2091 for _, test := range []struct {
2092 x, y Type
2093 want bool
2094 }{
2095 {Typ[Int], Typ[Int], true},
2096 {Typ[Int], nil, false},
2097 {nil, Typ[Int], false},
2098 {nil, nil, true},
2099 } {
2100 if got := Identical(test.x, test.y); got != test.want {
2101 t.Errorf("Identical(%v, %v) = %t", test.x, test.y, got)
2102 }
2103 }
2104 }
2105
2106 func TestIdenticalUnions(t *testing.T) {
2107 tname := NewTypeName(nopos, nil, "myInt", nil)
2108 myInt := NewNamed(tname, Typ[Int], nil)
2109 tmap := map[string]*Term{
2110 "int": NewTerm(false, Typ[Int]),
2111 "~int": NewTerm(true, Typ[Int]),
2112 "string": NewTerm(false, Typ[String]),
2113 "~string": NewTerm(true, Typ[String]),
2114 "myInt": NewTerm(false, myInt),
2115 }
2116 makeUnion := func(s string) *Union {
2117 parts := strings.Split(s, "|")
2118 var terms []*Term
2119 for _, p := range parts {
2120 term := tmap[p]
2121 if term == nil {
2122 t.Fatalf("missing term %q", p)
2123 }
2124 terms = append(terms, term)
2125 }
2126 return NewUnion(terms)
2127 }
2128 for _, test := range []struct {
2129 x, y string
2130 want bool
2131 }{
2132 // These tests are just sanity checks. The tests for type sets and
2133 // interfaces provide much more test coverage.
2134 {"int|~int", "~int", true},
2135 {"myInt|~int", "~int", true},
2136 {"int|string", "string|int", true},
2137 {"int|int|string", "string|int", true},
2138 {"myInt|string", "int|string", false},
2139 } {
2140 x := makeUnion(test.x)
2141 y := makeUnion(test.y)
2142 if got := Identical(x, y); got != test.want {
2143 t.Errorf("Identical(%v, %v) = %t", test.x, test.y, got)
2144 }
2145 }
2146 }
2147
2148 func TestIssue61737(t *testing.T) {
2149 // This test verifies that it is possible to construct invalid interfaces
2150 // containing duplicate methods using the go/types API.
2151 //
2152 // It must be possible for importers to construct such invalid interfaces.
2153 // Previously, this panicked.
2154
2155 sig1 := NewSignatureType(nil, nil, nil, NewTuple(NewParam(nopos, nil, "", Typ[Int])), nil, false)
2156 sig2 := NewSignatureType(nil, nil, nil, NewTuple(NewParam(nopos, nil, "", Typ[String])), nil, false)
2157
2158 methods := []*Func{
2159 NewFunc(nopos, nil, "M", sig1),
2160 NewFunc(nopos, nil, "M", sig2),
2161 }
2162
2163 embeddedMethods := []*Func{
2164 NewFunc(nopos, nil, "M", sig2),
2165 }
2166 embedded := NewInterfaceType(embeddedMethods, nil)
2167 iface := NewInterfaceType(methods, []Type{embedded})
2168 iface.Complete()
2169 }
2170
2171 func TestNewAlias_Issue65455(t *testing.T) {
2172 obj := NewTypeName(nopos, nil, "A", nil)
2173 alias := NewAlias(obj, Typ[Int])
2174 alias.Underlying() // must not panic
2175 }
2176
2177 func TestIssue15305(t *testing.T) {
2178 const src = "package p; func f() int16; var _ = f(undef)"
2179 fset := token.NewFileSet()
2180 f := mustParse(fset, src)
2181 conf := Config{
2182 Error: func(err error) {}, // allow errors
2183 }
2184 info := &Info{
2185 Types: make(map[ast.Expr]TypeAndValue),
2186 }
2187 conf.Check("p", fset, []*ast.File{f}, info) // ignore result
2188 for e, tv := range info.Types {
2189 if _, ok := e.(*ast.CallExpr); ok {
2190 if tv.Type != Typ[Int16] {
2191 t.Errorf("CallExpr has type %v, want int16", tv.Type)
2192 }
2193 return
2194 }
2195 }
2196 t.Errorf("CallExpr has no type")
2197 }
2198
2199 // TestCompositeLitTypes verifies that Info.Types registers the correct
2200 // types for composite literal expressions and composite literal type
2201 // expressions.
2202 func TestCompositeLitTypes(t *testing.T) {
2203 for i, test := range []struct {
2204 lit, typ string
2205 }{
2206 {`[16]byte{}`, `[16]byte`},
2207 {`[...]byte{}`, `[0]byte`}, // test for go.dev/issue/14092
2208 {`[...]int{1, 2, 3}`, `[3]int`}, // test for go.dev/issue/14092
2209 {`[...]int{90: 0, 98: 1, 2}`, `[100]int`}, // test for go.dev/issue/14092
2210 {`[]int{}`, `[]int`},
2211 {`map[string]bool{"foo": true}`, `map[string]bool`},
2212 {`struct{}{}`, `struct{}`},
2213 {`struct{x, y int; z complex128}{}`, `struct{x int; y int; z complex128}`},
2214 } {
2215 fset := token.NewFileSet()
2216 f := mustParse(fset, fmt.Sprintf("package p%d; var _ = %s", i, test.lit))
2217 types := make(map[ast.Expr]TypeAndValue)
2218 if _, err := new(Config).Check("p", fset, []*ast.File{f}, &Info{Types: types}); err != nil {
2219 t.Fatalf("%s: %v", test.lit, err)
2220 }
2221
2222 cmptype := func(x ast.Expr, want string) {
2223 tv, ok := types[x]
2224 if !ok {
2225 t.Errorf("%s: no Types entry found", test.lit)
2226 return
2227 }
2228 if tv.Type == nil {
2229 t.Errorf("%s: type is nil", test.lit)
2230 return
2231 }
2232 if got := tv.Type.String(); got != want {
2233 t.Errorf("%s: got %v, want %s", test.lit, got, want)
2234 }
2235 }
2236
2237 // test type of composite literal expression
2238 rhs := f.Decls[0].(*ast.GenDecl).Specs[0].(*ast.ValueSpec).Values[0]
2239 cmptype(rhs, test.typ)
2240
2241 // test type of composite literal type expression
2242 cmptype(rhs.(*ast.CompositeLit).Type, test.typ)
2243 }
2244 }
2245
2246 // TestObjectParents verifies that objects have parent scopes or not
2247 // as specified by the Object interface.
2248 func TestObjectParents(t *testing.T) {
2249 const src = `
2250 package p
2251
2252 const C = 0
2253
2254 type T1 struct {
2255 a, b int
2256 T2
2257 }
2258
2259 type T2 interface {
2260 im1()
2261 im2()
2262 }
2263
2264 func (T1) m1() {}
2265 func (*T1) m2() {}
2266
2267 func f(x int) { y := x; print(y) }
2268 `
2269
2270 fset := token.NewFileSet()
2271 f := mustParse(fset, src)
2272
2273 info := &Info{
2274 Defs: make(map[*ast.Ident]Object),
2275 }
2276 if _, err := new(Config).Check("p", fset, []*ast.File{f}, info); err != nil {
2277 t.Fatal(err)
2278 }
2279
2280 for ident, obj := range info.Defs {
2281 if obj == nil {
2282 // only package names and implicit vars have a nil object
2283 // (in this test we only need to handle the package name)
2284 if ident.Name != "p" {
2285 t.Errorf("%v has nil object", ident)
2286 }
2287 continue
2288 }
2289
2290 // struct fields, type-associated and interface methods
2291 // have no parent scope
2292 wantParent := true
2293 switch obj := obj.(type) {
2294 case *Var:
2295 if obj.IsField() {
2296 wantParent = false
2297 }
2298 case *Func:
2299 if obj.Signature().Recv() != nil { // method
2300 wantParent = false
2301 }
2302 }
2303
2304 gotParent := obj.Parent() != nil
2305 switch {
2306 case gotParent && !wantParent:
2307 t.Errorf("%v: want no parent, got %s", ident, obj.Parent())
2308 case !gotParent && wantParent:
2309 t.Errorf("%v: no parent found", ident)
2310 }
2311 }
2312 }
2313
2314 // TestFailedImport tests that we don't get follow-on errors
2315 // elsewhere in a package due to failing to import a package.
2316 func TestFailedImport(t *testing.T) {
2317 testenv.MustHaveGoBuild(t)
2318
2319 const src = `
2320 package p
2321
2322 import foo "go/types/thisdirectorymustnotexistotherwisethistestmayfail/foo" // should only see an error here
2323
2324 const c = foo.C
2325 type T = foo.T
2326 var v T = c
2327 func f(x T) T { return foo.F(x) }
2328 `
2329 fset := token.NewFileSet()
2330 f := mustParse(fset, src)
2331 files := []*ast.File{f}
2332
2333 // type-check using all possible importers
2334 for _, compiler := range []string{"gc", "gccgo", "source"} {
2335 errcount := 0
2336 conf := Config{
2337 Error: func(err error) {
2338 // we should only see the import error
2339 if errcount > 0 || !strings.Contains(err.Error(), "could not import") {
2340 t.Errorf("for %s importer, got unexpected error: %v", compiler, err)
2341 }
2342 errcount++
2343 },
2344 Importer: importer.For(compiler, nil),
2345 }
2346
2347 info := &Info{
2348 Uses: make(map[*ast.Ident]Object),
2349 }
2350 pkg, _ := conf.Check("p", fset, files, info)
2351 if pkg == nil {
2352 t.Errorf("for %s importer, type-checking failed to return a package", compiler)
2353 continue
2354 }
2355
2356 imports := pkg.Imports()
2357 if len(imports) != 1 {
2358 t.Errorf("for %s importer, got %d imports, want 1", compiler, len(imports))
2359 continue
2360 }
2361 imp := imports[0]
2362 if imp.Name() != "foo" {
2363 t.Errorf(`for %s importer, got %q, want "foo"`, compiler, imp.Name())
2364 continue
2365 }
2366
2367 // verify that all uses of foo refer to the imported package foo (imp)
2368 for ident, obj := range info.Uses {
2369 if ident.Name == "foo" {
2370 if obj, ok := obj.(*PkgName); ok {
2371 if obj.Imported() != imp {
2372 t.Errorf("%s resolved to %v; want %v", ident, obj.Imported(), imp)
2373 }
2374 } else {
2375 t.Errorf("%s resolved to %v; want package name", ident, obj)
2376 }
2377 }
2378 }
2379 }
2380 }
2381
2382 func TestInstantiate(t *testing.T) {
2383 // eventually we like more tests but this is a start
2384 const src = "package p; type T[P any] *T[P]"
2385 pkg := mustTypecheck(src, nil, nil)
2386
2387 // type T should have one type parameter
2388 T := pkg.Scope().Lookup("T").Type().(*Named)
2389 if n := T.TypeParams().Len(); n != 1 {
2390 t.Fatalf("expected 1 type parameter; found %d", n)
2391 }
2392
2393 // instantiation should succeed (no endless recursion)
2394 // even with a nil *Checker
2395 res, err := Instantiate(nil, T, []Type{Typ[Int]}, false)
2396 if err != nil {
2397 t.Fatal(err)
2398 }
2399
2400 // instantiated type should point to itself
2401 if p := res.Underlying().(*Pointer).Elem(); p != res {
2402 t.Fatalf("unexpected result type: %s points to %s", res, p)
2403 }
2404 }
2405
2406 func TestInstantiateConcurrent(t *testing.T) {
2407 const src = `package p
2408
2409 type I[P any] interface {
2410 m(P)
2411 n() P
2412 }
2413
2414 type J = I[int]
2415
2416 type Nested[P any] *interface{b(P)}
2417
2418 type K = Nested[string]
2419 `
2420 pkg := mustTypecheck(src, nil, nil)
2421
2422 insts := []*Interface{
2423 pkg.Scope().Lookup("J").Type().Underlying().(*Interface),
2424 pkg.Scope().Lookup("K").Type().Underlying().(*Pointer).Elem().(*Interface),
2425 }
2426
2427 // Use the interface instances concurrently.
2428 for _, inst := range insts {
2429 var (
2430 counts [2]int // method counts
2431 methods [2][]string // method strings
2432 )
2433 var wg sync.WaitGroup
2434 for i := 0; i < 2; i++ {
2435 i := i
2436 wg.Add(1)
2437 go func() {
2438 defer wg.Done()
2439
2440 counts[i] = inst.NumMethods()
2441 for mi := 0; mi < counts[i]; mi++ {
2442 methods[i] = append(methods[i], inst.Method(mi).String())
2443 }
2444 }()
2445 }
2446 wg.Wait()
2447
2448 if counts[0] != counts[1] {
2449 t.Errorf("mismatching method counts for %s: %d vs %d", inst, counts[0], counts[1])
2450 continue
2451 }
2452 for i := 0; i < counts[0]; i++ {
2453 if m0, m1 := methods[0][i], methods[1][i]; m0 != m1 {
2454 t.Errorf("mismatching methods for %s: %s vs %s", inst, m0, m1)
2455 }
2456 }
2457 }
2458 }
2459
2460 func TestInstantiateErrors(t *testing.T) {
2461 tests := []struct {
2462 src string // by convention, T must be the type being instantiated
2463 targs []Type
2464 wantAt int // -1 indicates no error
2465 }{
2466 {"type T[P interface{~string}] int", []Type{Typ[Int]}, 0},
2467 {"type T[P1 interface{int}, P2 interface{~string}] int", []Type{Typ[Int], Typ[Int]}, 1},
2468 {"type T[P1 any, P2 interface{~[]P1}] int", []Type{Typ[Int], NewSlice(Typ[String])}, 1},
2469 {"type T[P1 interface{~[]P2}, P2 any] int", []Type{NewSlice(Typ[String]), Typ[Int]}, 0},
2470 }
2471
2472 for _, test := range tests {
2473 src := "package p; " + test.src
2474 pkg := mustTypecheck(src, nil, nil)
2475
2476 T := pkg.Scope().Lookup("T").Type().(*Named)
2477
2478 _, err := Instantiate(nil, T, test.targs, true)
2479 if err == nil {
2480 t.Fatalf("Instantiate(%v, %v) returned nil error, want non-nil", T, test.targs)
2481 }
2482
2483 var argErr *ArgumentError
2484 if !errors.As(err, &argErr) {
2485 t.Fatalf("Instantiate(%v, %v): error is not an *ArgumentError", T, test.targs)
2486 }
2487
2488 if argErr.Index != test.wantAt {
2489 t.Errorf("Instantiate(%v, %v): error at index %d, want index %d", T, test.targs, argErr.Index, test.wantAt)
2490 }
2491 }
2492 }
2493
2494 func TestArgumentErrorUnwrapping(t *testing.T) {
2495 var err error = &ArgumentError{
2496 Index: 1,
2497 Err: Error{Msg: "test"},
2498 }
2499 var e Error
2500 if !errors.As(err, &e) {
2501 t.Fatalf("error %v does not wrap types.Error", err)
2502 }
2503 if e.Msg != "test" {
2504 t.Errorf("e.Msg = %q, want %q", e.Msg, "test")
2505 }
2506 }
2507
2508 func TestInstanceIdentity(t *testing.T) {
2509 imports := make(testImporter)
2510 conf := Config{Importer: imports}
2511 makePkg := func(src string) {
2512 fset := token.NewFileSet()
2513 f := mustParse(fset, src)
2514 name := f.Name.Name
2515 pkg, err := conf.Check(name, fset, []*ast.File{f}, nil)
2516 if err != nil {
2517 t.Fatal(err)
2518 }
2519 imports[name] = pkg
2520 }
2521 makePkg(`package lib; type T[P any] struct{}`)
2522 makePkg(`package a; import "lib"; var A lib.T[int]`)
2523 makePkg(`package b; import "lib"; var B lib.T[int]`)
2524 a := imports["a"].Scope().Lookup("A")
2525 b := imports["b"].Scope().Lookup("B")
2526 if !Identical(a.Type(), b.Type()) {
2527 t.Errorf("mismatching types: a.A: %s, b.B: %s", a.Type(), b.Type())
2528 }
2529 }
2530
2531 // TestInstantiatedObjects verifies properties of instantiated objects.
2532 func TestInstantiatedObjects(t *testing.T) {
2533 const src = `
2534 package p
2535
2536 type T[P any] struct {
2537 field P
2538 }
2539
2540 func (recv *T[Q]) concreteMethod(mParam Q) (mResult Q) { return }
2541
2542 type FT[P any] func(ftParam P) (ftResult P)
2543
2544 func F[P any](fParam P) (fResult P){ return }
2545
2546 type I[P any] interface {
2547 interfaceMethod(P)
2548 }
2549
2550 type R[P any] T[P]
2551
2552 func (R[P]) m() {} // having a method triggers expansion of R
2553
2554 var (
2555 t T[int]
2556 ft FT[int]
2557 f = F[int]
2558 i I[int]
2559 )
2560
2561 func fn() {
2562 var r R[int]
2563 _ = r
2564 }
2565 `
2566 info := &Info{
2567 Defs: make(map[*ast.Ident]Object),
2568 }
2569 fset := token.NewFileSet()
2570 f := mustParse(fset, src)
2571 conf := Config{}
2572 pkg, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, info)
2573 if err != nil {
2574 t.Fatal(err)
2575 }
2576
2577 lookup := func(name string) Type { return pkg.Scope().Lookup(name).Type() }
2578 fnScope := pkg.Scope().Lookup("fn").(*Func).Scope()
2579
2580 tests := []struct {
2581 name string
2582 obj Object
2583 }{
2584 // Struct fields
2585 {"field", lookup("t").Underlying().(*Struct).Field(0)},
2586 {"field", fnScope.Lookup("r").Type().Underlying().(*Struct).Field(0)},
2587
2588 // Methods and method fields
2589 {"concreteMethod", lookup("t").(*Named).Method(0)},
2590 {"recv", lookup("t").(*Named).Method(0).Signature().Recv()},
2591 {"mParam", lookup("t").(*Named).Method(0).Signature().Params().At(0)},
2592 {"mResult", lookup("t").(*Named).Method(0).Signature().Results().At(0)},
2593
2594 // Interface methods
2595 {"interfaceMethod", lookup("i").Underlying().(*Interface).Method(0)},
2596
2597 // Function type fields
2598 {"ftParam", lookup("ft").Underlying().(*Signature).Params().At(0)},
2599 {"ftResult", lookup("ft").Underlying().(*Signature).Results().At(0)},
2600
2601 // Function fields
2602 {"fParam", lookup("f").(*Signature).Params().At(0)},
2603 {"fResult", lookup("f").(*Signature).Results().At(0)},
2604 }
2605
2606 // Collect all identifiers by name.
2607 idents := make(map[string][]*ast.Ident)
2608 ast.Inspect(f, func(n ast.Node) bool {
2609 if id, ok := n.(*ast.Ident); ok {
2610 idents[id.Name] = append(idents[id.Name], id)
2611 }
2612 return true
2613 })
2614
2615 for _, test := range tests {
2616 test := test
2617 t.Run(test.name, func(t *testing.T) {
2618 if got := len(idents[test.name]); got != 1 {
2619 t.Fatalf("found %d identifiers named %s, want 1", got, test.name)
2620 }
2621 ident := idents[test.name][0]
2622 def := info.Defs[ident]
2623 if def == test.obj {
2624 t.Fatalf("info.Defs[%s] contains the test object", test.name)
2625 }
2626 if orig := originObject(test.obj); def != orig {
2627 t.Errorf("info.Defs[%s] does not match obj.Origin()", test.name)
2628 }
2629 if def.Pkg() != test.obj.Pkg() {
2630 t.Errorf("Pkg() = %v, want %v", def.Pkg(), test.obj.Pkg())
2631 }
2632 if def.Name() != test.obj.Name() {
2633 t.Errorf("Name() = %v, want %v", def.Name(), test.obj.Name())
2634 }
2635 if def.Pos() != test.obj.Pos() {
2636 t.Errorf("Pos() = %v, want %v", def.Pos(), test.obj.Pos())
2637 }
2638 if def.Parent() != test.obj.Parent() {
2639 t.Fatalf("Parent() = %v, want %v", def.Parent(), test.obj.Parent())
2640 }
2641 if def.Exported() != test.obj.Exported() {
2642 t.Fatalf("Exported() = %v, want %v", def.Exported(), test.obj.Exported())
2643 }
2644 if def.Id() != test.obj.Id() {
2645 t.Fatalf("Id() = %v, want %v", def.Id(), test.obj.Id())
2646 }
2647 // String and Type are expected to differ.
2648 })
2649 }
2650 }
2651
2652 func originObject(obj Object) Object {
2653 switch obj := obj.(type) {
2654 case *Var:
2655 return obj.Origin()
2656 case *Func:
2657 return obj.Origin()
2658 }
2659 return obj
2660 }
2661
2662 func TestImplements(t *testing.T) {
2663 const src = `
2664 package p
2665
2666 type EmptyIface interface{}
2667
2668 type I interface {
2669 m()
2670 }
2671
2672 type C interface {
2673 m()
2674 ~int
2675 }
2676
2677 type Integer interface{
2678 int8 | int16 | int32 | int64
2679 }
2680
2681 type EmptyTypeSet interface{
2682 Integer
2683 ~string
2684 }
2685
2686 type N1 int
2687 func (N1) m() {}
2688
2689 type N2 int
2690 func (*N2) m() {}
2691
2692 type N3 int
2693 func (N3) m(int) {}
2694
2695 type N4 string
2696 func (N4) m()
2697
2698 type Bad Bad // invalid type
2699 `
2700
2701 fset := token.NewFileSet()
2702 f := mustParse(fset, src)
2703 conf := Config{Error: func(error) {}}
2704 pkg, _ := conf.Check(f.Name.Name, fset, []*ast.File{f}, nil)
2705
2706 lookup := func(tname string) Type { return pkg.Scope().Lookup(tname).Type() }
2707 var (
2708 EmptyIface = lookup("EmptyIface").Underlying().(*Interface)
2709 I = lookup("I").(*Named)
2710 II = I.Underlying().(*Interface)
2711 C = lookup("C").(*Named)
2712 CI = C.Underlying().(*Interface)
2713 Integer = lookup("Integer").Underlying().(*Interface)
2714 EmptyTypeSet = lookup("EmptyTypeSet").Underlying().(*Interface)
2715 N1 = lookup("N1")
2716 N1p = NewPointer(N1)
2717 N2 = lookup("N2")
2718 N2p = NewPointer(N2)
2719 N3 = lookup("N3")
2720 N4 = lookup("N4")
2721 Bad = lookup("Bad")
2722 )
2723
2724 tests := []struct {
2725 V Type
2726 T *Interface
2727 want bool
2728 }{
2729 {I, II, true},
2730 {I, CI, false},
2731 {C, II, true},
2732 {C, CI, true},
2733 {Typ[Int8], Integer, true},
2734 {Typ[Int64], Integer, true},
2735 {Typ[String], Integer, false},
2736 {EmptyTypeSet, II, true},
2737 {EmptyTypeSet, EmptyTypeSet, true},
2738 {Typ[Int], EmptyTypeSet, false},
2739 {N1, II, true},
2740 {N1, CI, true},
2741 {N1p, II, true},
2742 {N1p, CI, false},
2743 {N2, II, false},
2744 {N2, CI, false},
2745 {N2p, II, true},
2746 {N2p, CI, false},
2747 {N3, II, false},
2748 {N3, CI, false},
2749 {N4, II, true},
2750 {N4, CI, false},
2751 {Bad, II, false},
2752 {Bad, CI, false},
2753 {Bad, EmptyIface, true},
2754 }
2755
2756 for _, test := range tests {
2757 if got := Implements(test.V, test.T); got != test.want {
2758 t.Errorf("Implements(%s, %s) = %t, want %t", test.V, test.T, got, test.want)
2759 }
2760
2761 // The type assertion x.(T) is valid if T is an interface or if T implements the type of x.
2762 // The assertion is never valid if T is a bad type.
2763 V := test.T
2764 T := test.V
2765 want := false
2766 if _, ok := T.Underlying().(*Interface); (ok || Implements(T, V)) && T != Bad {
2767 want = true
2768 }
2769 if got := AssertableTo(V, T); got != want {
2770 t.Errorf("AssertableTo(%s, %s) = %t, want %t", V, T, got, want)
2771 }
2772 }
2773 }
2774
2775 func TestMissingMethodAlternative(t *testing.T) {
2776 const src = `
2777 package p
2778 type T interface {
2779 m()
2780 }
2781
2782 type V0 struct{}
2783 func (V0) m() {}
2784
2785 type V1 struct{}
2786
2787 type V2 struct{}
2788 func (V2) m() int
2789
2790 type V3 struct{}
2791 func (*V3) m()
2792
2793 type V4 struct{}
2794 func (V4) M()
2795 `
2796
2797 pkg := mustTypecheck(src, nil, nil)
2798
2799 T := pkg.Scope().Lookup("T").Type().Underlying().(*Interface)
2800 lookup := func(name string) (*Func, bool) {
2801 return MissingMethod(pkg.Scope().Lookup(name).Type(), T, true)
2802 }
2803
2804 // V0 has method m with correct signature. Should not report wrongType.
2805 method, wrongType := lookup("V0")
2806 if method != nil || wrongType {
2807 t.Fatalf("V0: got method = %v, wrongType = %v", method, wrongType)
2808 }
2809
2810 checkMissingMethod := func(tname string, reportWrongType bool) {
2811 method, wrongType := lookup(tname)
2812 if method == nil || method.Name() != "m" || wrongType != reportWrongType {
2813 t.Fatalf("%s: got method = %v, wrongType = %v", tname, method, wrongType)
2814 }
2815 }
2816
2817 // V1 has no method m. Should not report wrongType.
2818 checkMissingMethod("V1", false)
2819
2820 // V2 has method m with wrong signature type (ignoring receiver). Should report wrongType.
2821 checkMissingMethod("V2", true)
2822
2823 // V3 has no method m but it exists on *V3. Should report wrongType.
2824 checkMissingMethod("V3", true)
2825
2826 // V4 has no method m but has M. Should not report wrongType.
2827 checkMissingMethod("V4", false)
2828 }
2829
2830 func TestErrorURL(t *testing.T) {
2831 var conf Config
2832 *stringFieldAddr(&conf, "_ErrorURL") = " [go.dev/e/%s]"
2833
2834 // test case for a one-line error
2835 const src1 = `
2836 package p
2837 var _ T
2838 `
2839 _, err := typecheck(src1, &conf, nil)
2840 if err == nil || !strings.HasSuffix(err.Error(), " [go.dev/e/UndeclaredName]") {
2841 t.Errorf("src1: unexpected error: got %v", err)
2842 }
2843
2844 // test case for a multi-line error
2845 const src2 = `
2846 package p
2847 func f() int { return 0 }
2848 var _ = f(1, 2)
2849 `
2850 _, err = typecheck(src2, &conf, nil)
2851 if err == nil || !strings.Contains(err.Error(), " [go.dev/e/WrongArgCount]\n") {
2852 t.Errorf("src1: unexpected error: got %v", err)
2853 }
2854 }
2855
2856 func TestModuleVersion(t *testing.T) {
2857 // version go1.dd must be able to typecheck go1.dd.0, go1.dd.1, etc.
2858 goversion := fmt.Sprintf("go1.%d", goversion.Version)
2859 for _, v := range []string{
2860 goversion,
2861 goversion + ".0",
2862 goversion + ".1",
2863 goversion + ".rc",
2864 } {
2865 conf := Config{GoVersion: v}
2866 pkg := mustTypecheck("package p", &conf, nil)
2867 if pkg.GoVersion() != conf.GoVersion {
2868 t.Errorf("got %s; want %s", pkg.GoVersion(), conf.GoVersion)
2869 }
2870 }
2871 }
2872
2873 func TestFileVersions(t *testing.T) {
2874 for _, test := range []struct {
2875 goVersion string
2876 fileVersion string
2877 wantVersion string
2878 }{
2879 {"", "", ""}, // no versions specified
2880 {"go1.19", "", "go1.19"}, // module version specified
2881 {"", "go1.20", "go1.21"}, // file version specified below minimum of 1.21
2882 {"go1", "", "go1"}, // no file version specified
2883 {"go1", "goo1.22", "go1"}, // invalid file version specified
2884 {"go1", "go1.19", "go1.21"}, // file version specified below minimum of 1.21
2885 {"go1", "go1.20", "go1.21"}, // file version specified below minimum of 1.21
2886 {"go1", "go1.21", "go1.21"}, // file version specified at 1.21
2887 {"go1", "go1.22", "go1.22"}, // file version specified above 1.21
2888 {"go1.19", "", "go1.19"}, // no file version specified
2889 {"go1.19", "goo1.22", "go1.19"}, // invalid file version specified
2890 {"go1.19", "go1.20", "go1.21"}, // file version specified below minimum of 1.21
2891 {"go1.19", "go1.21", "go1.21"}, // file version specified at 1.21
2892 {"go1.19", "go1.22", "go1.22"}, // file version specified above 1.21
2893 {"go1.20", "", "go1.20"}, // no file version specified
2894 {"go1.20", "goo1.22", "go1.20"}, // invalid file version specified
2895 {"go1.20", "go1.19", "go1.21"}, // file version specified below minimum of 1.21
2896 {"go1.20", "go1.20", "go1.21"}, // file version specified below minimum of 1.21
2897 {"go1.20", "go1.21", "go1.21"}, // file version specified at 1.21
2898 {"go1.20", "go1.22", "go1.22"}, // file version specified above 1.21
2899 {"go1.21", "", "go1.21"}, // no file version specified
2900 {"go1.21", "goo1.22", "go1.21"}, // invalid file version specified
2901 {"go1.21", "go1.19", "go1.21"}, // file version specified below minimum of 1.21
2902 {"go1.21", "go1.20", "go1.21"}, // file version specified below minimum of 1.21
2903 {"go1.21", "go1.21", "go1.21"}, // file version specified at 1.21
2904 {"go1.21", "go1.22", "go1.22"}, // file version specified above 1.21
2905 {"go1.22", "", "go1.22"}, // no file version specified
2906 {"go1.22", "goo1.22", "go1.22"}, // invalid file version specified
2907 {"go1.22", "go1.19", "go1.21"}, // file version specified below minimum of 1.21
2908 {"go1.22", "go1.20", "go1.21"}, // file version specified below minimum of 1.21
2909 {"go1.22", "go1.21", "go1.21"}, // file version specified at 1.21
2910 {"go1.22", "go1.22", "go1.22"}, // file version specified above 1.21
2911
2912 // versions containing release numbers
2913 // (file versions containing release numbers are considered invalid)
2914 {"go1.19.0", "", "go1.19.0"}, // no file version specified
2915 {"go1.20.1", "go1.19.1", "go1.20.1"}, // invalid file version
2916 {"go1.20.1", "go1.21.1", "go1.20.1"}, // invalid file version
2917 {"go1.21.1", "go1.19.1", "go1.21.1"}, // invalid file version
2918 {"go1.21.1", "go1.21.1", "go1.21.1"}, // invalid file version
2919 {"go1.22.1", "go1.19.1", "go1.22.1"}, // invalid file version
2920 {"go1.22.1", "go1.21.1", "go1.22.1"}, // invalid file version
2921 } {
2922 var src string
2923 if test.fileVersion != "" {
2924 src = "//go:build " + test.fileVersion + "\n"
2925 }
2926 src += "package p"
2927
2928 conf := Config{GoVersion: test.goVersion}
2929 versions := make(map[*ast.File]string)
2930 var info Info
2931 info.FileVersions = versions
2932 mustTypecheck(src, &conf, &info)
2933
2934 n := 0
2935 for _, v := range versions {
2936 want := test.wantVersion
2937 if v != want {
2938 t.Errorf("%q: unexpected file version: got %q, want %q", src, v, want)
2939 }
2940 n++
2941 }
2942 if n != 1 {
2943 t.Errorf("%q: incorrect number of map entries: got %d", src, n)
2944 }
2945 }
2946 }
2947
2948 // TestTooNew ensures that "too new" errors are emitted when the file
2949 // or module is tagged with a newer version of Go than this go/types.
2950 func TestTooNew(t *testing.T) {
2951 for _, test := range []struct {
2952 goVersion string // package's Go version (as if derived from go.mod file)
2953 fileVersion string // file's Go version (becomes a build tag)
2954 wantErr string // expected substring of concatenation of all errors
2955 }{
2956 {"go1.98", "", "package requires newer Go version go1.98"},
2957 {"", "go1.99", "p:2:9: file requires newer Go version go1.99"},
2958 {"go1.98", "go1.99", "package requires newer Go version go1.98"}, // (two
2959 {"go1.98", "go1.99", "file requires newer Go version go1.99"}, // errors)
2960 } {
2961 var src string
2962 if test.fileVersion != "" {
2963 src = "//go:build " + test.fileVersion + "\n"
2964 }
2965 src += "package p; func f()"
2966
2967 var errs []error
2968 conf := Config{
2969 GoVersion: test.goVersion,
2970 Error: func(err error) { errs = append(errs, err) },
2971 }
2972 info := &Info{Defs: make(map[*ast.Ident]Object)}
2973 typecheck(src, &conf, info)
2974 got := fmt.Sprint(errs)
2975 if !strings.Contains(got, test.wantErr) {
2976 t.Errorf("%q: unexpected error: got %q, want substring %q",
2977 src, got, test.wantErr)
2978 }
2979
2980 // Assert that declarations were type checked nonetheless.
2981 var gotObjs []string
2982 for id, obj := range info.Defs {
2983 if obj != nil {
2984 objStr := strings.ReplaceAll(fmt.Sprintf("%s:%T", id.Name, obj), "types2", "types")
2985 gotObjs = append(gotObjs, objStr)
2986 }
2987 }
2988 wantObjs := "f:*types.Func"
2989 if !strings.Contains(fmt.Sprint(gotObjs), wantObjs) {
2990 t.Errorf("%q: got %s, want substring %q",
2991 src, gotObjs, wantObjs)
2992 }
2993 }
2994 }
2995
2996 // This is a regression test for #66704.
2997 func TestUnaliasTooSoonInCycle(t *testing.T) {
2998 setGotypesalias(t, true)
2999 const src = `package a
3000
3001 var x T[B] // this appears to cause Unalias to be called on B while still Invalid
3002
3003 type T[_ any] struct{}
3004 type A T[B]
3005 type B = T[A]
3006 `
3007 pkg := mustTypecheck(src, nil, nil)
3008 B := pkg.Scope().Lookup("B")
3009
3010 got, want := Unalias(B.Type()).String(), "a.T[a.A]"
3011 if got != want {
3012 t.Errorf("Unalias(type B = T[A]) = %q, want %q", got, want)
3013 }
3014 }
3015
3016 func TestAlias_Rhs(t *testing.T) {
3017 setGotypesalias(t, true)
3018 const src = `package p
3019
3020 type A = B
3021 type B = C
3022 type C = int
3023 `
3024
3025 pkg := mustTypecheck(src, nil, nil)
3026 A := pkg.Scope().Lookup("A")
3027
3028 got, want := A.Type().(*Alias).Rhs().String(), "p.B"
3029 if got != want {
3030 t.Errorf("A.Rhs = %s, want %s", got, want)
3031 }
3032 }
3033
3034 // Test the hijacking described of "any" described in golang/go#66921, for type
3035 // checking.
3036 func TestAnyHijacking_Check(t *testing.T) {
3037 for _, enableAlias := range []bool{false, true} {
3038 t.Run(fmt.Sprintf("EnableAlias=%t", enableAlias), func(t *testing.T) {
3039 setGotypesalias(t, enableAlias)
3040 var wg sync.WaitGroup
3041 for i := 0; i < 10; i++ {
3042 wg.Add(1)
3043 go func() {
3044 defer wg.Done()
3045 pkg := mustTypecheck("package p; var x any", nil, nil)
3046 x := pkg.Scope().Lookup("x")
3047 if _, gotAlias := x.Type().(*Alias); gotAlias != enableAlias {
3048 t.Errorf(`Lookup("x").Type() is %T: got Alias: %t, want %t`, x.Type(), gotAlias, enableAlias)
3049 }
3050 }()
3051 }
3052 wg.Wait()
3053 })
3054 }
3055 }
3056
3057 // Test the hijacking described of "any" described in golang/go#66921, for
3058 // Scope.Lookup outside of type checking.
3059 func TestAnyHijacking_Lookup(t *testing.T) {
3060 for _, enableAlias := range []bool{false, true} {
3061 t.Run(fmt.Sprintf("EnableAlias=%t", enableAlias), func(t *testing.T) {
3062 setGotypesalias(t, enableAlias)
3063 a := Universe.Lookup("any")
3064 if _, gotAlias := a.Type().(*Alias); gotAlias != enableAlias {
3065 t.Errorf(`Lookup("x").Type() is %T: got Alias: %t, want %t`, a.Type(), gotAlias, enableAlias)
3066 }
3067 })
3068 }
3069 }
3070
3071 func setGotypesalias(t *testing.T, enable bool) {
3072 if enable {
3073 t.Setenv("GODEBUG", "gotypesalias=1")
3074 } else {
3075 t.Setenv("GODEBUG", "gotypesalias=0")
3076 }
3077 }
3078
3079 // TestVersionIssue69477 is a regression test for issue #69477,
3080 // in which the type checker would panic while attempting
3081 // to compute which file it is "in" based on syntax position.
3082 func TestVersionIssue69477(t *testing.T) {
3083 fset := token.NewFileSet()
3084 f, _ := parser.ParseFile(fset, "a.go", "package p; const k = 123", 0)
3085
3086 // Set an invalid Pos on the BasicLit.
3087 ast.Inspect(f, func(n ast.Node) bool {
3088 if lit, ok := n.(*ast.BasicLit); ok {
3089 lit.ValuePos = 99999
3090 }
3091 return true
3092 })
3093
3094 // Type check. The checker will consult the effective
3095 // version for the BasicLit 123. This used to panic.
3096 pkg := NewPackage("p", "p")
3097 check := NewChecker(&Config{}, fset, pkg, nil)
3098 if err := check.Files([]*ast.File{f}); err != nil {
3099 t.Fatal(err)
3100 }
3101 }
3102
3103 // TestVersionWithoutPos is a regression test for issue #69477,
3104 // in which the type checker would use position information
3105 // to compute which file it is "in" based on syntax position.
3106 //
3107 // As a rule the type checker should not depend on position
3108 // information for correctness, only for error messages and
3109 // Object.Pos. (Scope.LookupParent was a mistake.)
3110 //
3111 // The Checker now holds the effective version in a state variable.
3112 func TestVersionWithoutPos(t *testing.T) {
3113 fset := token.NewFileSet()
3114 f, _ := parser.ParseFile(fset, "a.go", "//go:build go1.22\n\npackage p; var _ int", 0)
3115
3116 // Splice in a decl from another file. Its pos will be wrong.
3117 f2, _ := parser.ParseFile(fset, "a.go", "package q; func _(s func(func() bool)) { for range s {} }", 0)
3118 f.Decls[0] = f2.Decls[0]
3119
3120 // Type check. The checker will consult the effective
3121 // version (1.22) for the for-range stmt to know whether
3122 // range-over-func are permitted: they are not.
3123 // (Previously, no error was reported.)
3124 pkg := NewPackage("p", "p")
3125 check := NewChecker(&Config{}, fset, pkg, nil)
3126 err := check.Files([]*ast.File{f})
3127 got := fmt.Sprint(err)
3128 want := "range over s (variable of type func(func() bool)): requires go1.23"
3129 if !strings.Contains(got, want) {
3130 t.Errorf("check error was %q, want substring %q", got, want)
3131 }
3132 }
3133
3134 func TestVarKind(t *testing.T) {
3135 fset := token.NewFileSet()
3136 f, _ := parser.ParseFile(fset, "a.go", `package p
3137
3138 var global int
3139
3140 type T struct { field int }
3141
3142 func (recv T) f(param int) (result int) {
3143 var local int
3144 local2 := 0
3145 switch local3 := any(local).(type) {
3146 default:
3147 _ = local3
3148 }
3149 return local2
3150 }
3151 `, 0)
3152
3153 pkg := NewPackage("p", "p")
3154 info := &Info{Defs: make(map[*ast.Ident]Object)}
3155 check := NewChecker(&Config{}, fset, pkg, info)
3156 if err := check.Files([]*ast.File{f}); err != nil {
3157 t.Fatal(err)
3158 }
3159 var got []string
3160 for _, obj := range info.Defs {
3161 if v, ok := obj.(*Var); ok {
3162 got = append(got, fmt.Sprintf("%s: %v", v.Name(), v.Kind()))
3163 }
3164 }
3165 sort.Strings(got)
3166 want := []string{
3167 "field: FieldVar",
3168 "global: PackageVar",
3169 "local2: LocalVar",
3170 "local: LocalVar",
3171 "param: ParamVar",
3172 "recv: RecvVar",
3173 "result: ResultVar",
3174 }
3175 if !slices.Equal(got, want) {
3176 t.Errorf("got:\n%s\nwant:\n%s", got, want)
3177 }
3178 }
3179
3180 func TestIssue73871(t *testing.T) {
3181 const src = `package p
3182
3183 func f[T ~[]byte](y T) []byte { return append([]byte(nil), y...) }
3184
3185 // for illustration only:
3186 type B []byte
3187 var _ = f[B]
3188 `
3189 fset := token.NewFileSet()
3190 f, _ := parser.ParseFile(fset, "p.go", src, 0)
3191
3192 pkg := NewPackage("p", "p")
3193 info := &Info{Types: make(map[ast.Expr]TypeAndValue)}
3194 check := NewChecker(&Config{}, fset, pkg, info)
3195 if err := check.Files([]*ast.File{f}); err != nil {
3196 t.Fatal(err)
3197 }
3198
3199 // Check type inferred for 'append'.
3200 //
3201 // Before the fix, the inferred type of append's y parameter
3202 // was T. When a client such as x/tools/go/ssa instantiated T=B,
3203 // it would result in the Signature "func([]byte, B)" with the
3204 // variadic flag set, an invalid combination that caused
3205 // NewSignatureType to panic.
3206 append := f.Decls[0].(*ast.FuncDecl).Body.List[0].(*ast.ReturnStmt).Results[0].(*ast.CallExpr).Fun
3207 tAppend := info.TypeOf(append).(*Signature)
3208 want := "func([]byte, ...byte) []byte"
3209 if got := fmt.Sprint(tAppend); got != want {
3210 // Before the fix, tAppend was func([]byte, T) []byte,
3211 // where T prints as "<expected string type>".
3212 t.Errorf("for append, inferred type %s, want %s", tAppend, want)
3213 }
3214 }
3215