| 1 | // Copyright 2022 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package ssa |
| 6 | |
| 7 | // Note: Tests use unexported method _Instances. |
| 8 | |
| 9 | import ( |
| 10 | "bytes" |
| 11 | "fmt" |
| 12 | "go/types" |
| 13 | "reflect" |
| 14 | "sort" |
| 15 | "strings" |
| 16 | "testing" |
| 17 | |
| 18 | "golang.org/x/tools/go/loader" |
| 19 | "golang.org/x/tools/internal/typeparams" |
| 20 | ) |
| 21 | |
| 22 | // loadProgram creates loader.Program out of p. |
| 23 | func loadProgram(p string) (*loader.Program, error) { |
| 24 | // Parse |
| 25 | var conf loader.Config |
| 26 | f, err := conf.ParseFile("<input>", p) |
| 27 | if err != nil { |
| 28 | return nil, fmt.Errorf("parse: %v", err) |
| 29 | } |
| 30 | conf.CreateFromFiles("p", f) |
| 31 | |
| 32 | // Load |
| 33 | lprog, err := conf.Load() |
| 34 | if err != nil { |
| 35 | return nil, fmt.Errorf("Load: %v", err) |
| 36 | } |
| 37 | return lprog, nil |
| 38 | } |
| 39 | |
| 40 | // buildPackage builds and returns ssa representation of package pkg of lprog. |
| 41 | func buildPackage(lprog *loader.Program, pkg string, mode BuilderMode) *Package { |
| 42 | prog := NewProgram(lprog.Fset, mode) |
| 43 | |
| 44 | for _, info := range lprog.AllPackages { |
| 45 | prog.CreatePackage(info.Pkg, info.Files, &info.Info, info.Importable) |
| 46 | } |
| 47 | |
| 48 | p := prog.Package(lprog.Package(pkg).Pkg) |
| 49 | p.Build() |
| 50 | return p |
| 51 | } |
| 52 | |
| 53 | // TestNeedsInstance ensures that new method instances can be created via needsInstance, |
| 54 | // that TypeArgs are as expected, and can be accessed via _Instances. |
| 55 | func TestNeedsInstance(t *testing.T) { |
| 56 | if !typeparams.Enabled { |
| 57 | return |
| 58 | } |
| 59 | const input = ` |
| 60 | package p |
| 61 | |
| 62 | import "unsafe" |
| 63 | |
| 64 | type Pointer[T any] struct { |
| 65 | v unsafe.Pointer |
| 66 | } |
| 67 | |
| 68 | func (x *Pointer[T]) Load() *T { |
| 69 | return (*T)(LoadPointer(&x.v)) |
| 70 | } |
| 71 | |
| 72 | func LoadPointer(addr *unsafe.Pointer) (val unsafe.Pointer) |
| 73 | ` |
| 74 | // The SSA members for this package should look something like this: |
| 75 | // func LoadPointer func(addr *unsafe.Pointer) (val unsafe.Pointer) |
| 76 | // type Pointer struct{v unsafe.Pointer} |
| 77 | // method (*Pointer[T any]) Load() *T |
| 78 | // func init func() |
| 79 | // var init$guard bool |
| 80 | |
| 81 | lprog, err := loadProgram(input) |
| 82 | if err != err { |
| 83 | t.Fatal(err) |
| 84 | } |
| 85 | |
| 86 | for _, mode := range []BuilderMode{BuilderMode(0), InstantiateGenerics} { |
| 87 | // Create and build SSA |
| 88 | p := buildPackage(lprog, "p", mode) |
| 89 | prog := p.Prog |
| 90 | |
| 91 | ptr := p.Type("Pointer").Type().(*types.Named) |
| 92 | if ptr.NumMethods() != 1 { |
| 93 | t.Fatalf("Expected Pointer to have 1 method. got %d", ptr.NumMethods()) |
| 94 | } |
| 95 | |
| 96 | obj := ptr.Method(0) |
| 97 | if obj.Name() != "Load" { |
| 98 | t.Errorf("Expected Pointer to have method named 'Load'. got %q", obj.Name()) |
| 99 | } |
| 100 | |
| 101 | meth := prog.FuncValue(obj) |
| 102 | |
| 103 | var cr creator |
| 104 | intSliceTyp := types.NewSlice(types.Typ[types.Int]) |
| 105 | instance := prog.needsInstance(meth, []types.Type{intSliceTyp}, &cr) |
| 106 | if len(cr) != 1 { |
| 107 | t.Errorf("Expected first instance to create a function. got %d created functions", len(cr)) |
| 108 | } |
| 109 | if instance.Origin() != meth { |
| 110 | t.Errorf("Expected Origin of %s to be %s. got %s", instance, meth, instance.Origin()) |
| 111 | } |
| 112 | if len(instance.TypeArgs()) != 1 || !types.Identical(instance.TypeArgs()[0], intSliceTyp) { |
| 113 | t.Errorf("Expected TypeArgs of %s to be %v. got %v", instance, []types.Type{intSliceTyp}, instance.typeargs) |
| 114 | } |
| 115 | instances := prog._Instances(meth) |
| 116 | if want := []*Function{instance}; !reflect.DeepEqual(instances, want) { |
| 117 | t.Errorf("Expected instances of %s to be %v. got %v", meth, want, instances) |
| 118 | } |
| 119 | |
| 120 | // A second request with an identical type returns the same Function. |
| 121 | second := prog.needsInstance(meth, []types.Type{types.NewSlice(types.Typ[types.Int])}, &cr) |
| 122 | if second != instance || len(cr) != 1 { |
| 123 | t.Error("Expected second identical instantiation to not create a function") |
| 124 | } |
| 125 | |
| 126 | // Add a second instance. |
| 127 | inst2 := prog.needsInstance(meth, []types.Type{types.NewSlice(types.Typ[types.Uint])}, &cr) |
| 128 | instances = prog._Instances(meth) |
| 129 | |
| 130 | // Note: instance.Name() < inst2.Name() |
| 131 | sort.Slice(instances, func(i, j int) bool { |
| 132 | return instances[i].Name() < instances[j].Name() |
| 133 | }) |
| 134 | if want := []*Function{instance, inst2}; !reflect.DeepEqual(instances, want) { |
| 135 | t.Errorf("Expected instances of %s to be %v. got %v", meth, want, instances) |
| 136 | } |
| 137 | |
| 138 | // build and sanity check manually created instance. |
| 139 | var b builder |
| 140 | b.buildFunction(instance) |
| 141 | var buf bytes.Buffer |
| 142 | if !sanityCheck(instance, &buf) { |
| 143 | t.Errorf("sanityCheck of %s failed with: %s", instance, buf.String()) |
| 144 | } |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | // TestCallsToInstances checks that calles of calls to generic functions, |
| 149 | // without monomorphization, are wrappers around the origin generic function. |
| 150 | func TestCallsToInstances(t *testing.T) { |
| 151 | if !typeparams.Enabled { |
| 152 | return |
| 153 | } |
| 154 | const input = ` |
| 155 | package p |
| 156 | |
| 157 | type I interface { |
| 158 | Foo() |
| 159 | } |
| 160 | |
| 161 | type A int |
| 162 | func (a A) Foo() {} |
| 163 | |
| 164 | type J[T any] interface{ Bar() T } |
| 165 | type K[T any] struct{ J[T] } |
| 166 | |
| 167 | func Id[T any] (t T) T { |
| 168 | return t |
| 169 | } |
| 170 | |
| 171 | func Lambda[T I]() func() func(T) { |
| 172 | return func() func(T) { |
| 173 | return T.Foo |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | func NoOp[T any]() {} |
| 178 | |
| 179 | func Bar[T interface { Foo(); ~int | ~string }, U any] (t T, u U) { |
| 180 | Id[U](u) |
| 181 | Id[T](t) |
| 182 | } |
| 183 | |
| 184 | func Make[T any]() interface{} { |
| 185 | NoOp[K[T]]() |
| 186 | return nil |
| 187 | } |
| 188 | |
| 189 | func entry(i int, a A) int { |
| 190 | Lambda[A]()()(a) |
| 191 | |
| 192 | x := Make[int]() |
| 193 | if j, ok := x.(interface{ Bar() int }); ok { |
| 194 | print(j) |
| 195 | } |
| 196 | |
| 197 | Bar[A, int](a, i) |
| 198 | |
| 199 | return Id[int](i) |
| 200 | } |
| 201 | ` |
| 202 | lprog, err := loadProgram(input) |
| 203 | if err != err { |
| 204 | t.Fatal(err) |
| 205 | } |
| 206 | |
| 207 | p := buildPackage(lprog, "p", SanityCheckFunctions) |
| 208 | prog := p.Prog |
| 209 | |
| 210 | for _, ti := range []struct { |
| 211 | orig string |
| 212 | instance string |
| 213 | tparams string |
| 214 | targs string |
| 215 | chTypeInstrs int // number of ChangeType instructions in f's body |
| 216 | }{ |
| 217 | {"Id", "Id[int]", "[T]", "[int]", 2}, |
| 218 | {"Lambda", "Lambda[p.A]", "[T]", "[p.A]", 1}, |
| 219 | {"Make", "Make[int]", "[T]", "[int]", 0}, |
| 220 | {"NoOp", "NoOp[p.K[T]]", "[T]", "[p.K[T]]", 0}, |
| 221 | } { |
| 222 | test := ti |
| 223 | t.Run(test.instance, func(t *testing.T) { |
| 224 | f := p.Members[test.orig].(*Function) |
| 225 | if f == nil { |
| 226 | t.Fatalf("origin function not found") |
| 227 | } |
| 228 | |
| 229 | i := instanceOf(f, test.instance, prog) |
| 230 | if i == nil { |
| 231 | t.Fatalf("instance not found") |
| 232 | } |
| 233 | |
| 234 | // for logging on failures |
| 235 | var body strings.Builder |
| 236 | i.WriteTo(&body) |
| 237 | t.Log(body.String()) |
| 238 | |
| 239 | if len(i.Blocks) != 1 { |
| 240 | t.Fatalf("body has more than 1 block") |
| 241 | } |
| 242 | |
| 243 | if instrs := changeTypeInstrs(i.Blocks[0]); instrs != test.chTypeInstrs { |
| 244 | t.Errorf("want %v instructions; got %v", test.chTypeInstrs, instrs) |
| 245 | } |
| 246 | |
| 247 | if test.tparams != tparams(i) { |
| 248 | t.Errorf("want %v type params; got %v", test.tparams, tparams(i)) |
| 249 | } |
| 250 | |
| 251 | if test.targs != targs(i) { |
| 252 | t.Errorf("want %v type arguments; got %v", test.targs, targs(i)) |
| 253 | } |
| 254 | }) |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | func instanceOf(f *Function, name string, prog *Program) *Function { |
| 259 | for _, i := range prog._Instances(f) { |
| 260 | if i.Name() == name { |
| 261 | return i |
| 262 | } |
| 263 | } |
| 264 | return nil |
| 265 | } |
| 266 | |
| 267 | func tparams(f *Function) string { |
| 268 | tplist := f.TypeParams() |
| 269 | var tps []string |
| 270 | for i := 0; i < tplist.Len(); i++ { |
| 271 | tps = append(tps, tplist.At(i).String()) |
| 272 | } |
| 273 | return fmt.Sprint(tps) |
| 274 | } |
| 275 | |
| 276 | func targs(f *Function) string { |
| 277 | var tas []string |
| 278 | for _, ta := range f.TypeArgs() { |
| 279 | tas = append(tas, ta.String()) |
| 280 | } |
| 281 | return fmt.Sprint(tas) |
| 282 | } |
| 283 | |
| 284 | func changeTypeInstrs(b *BasicBlock) int { |
| 285 | cnt := 0 |
| 286 | for _, i := range b.Instrs { |
| 287 | if _, ok := i.(*ChangeType); ok { |
| 288 | cnt++ |
| 289 | } |
| 290 | } |
| 291 | return cnt |
| 292 | } |
| 293 | |
| 294 | func TestInstanceUniqueness(t *testing.T) { |
| 295 | if !typeparams.Enabled { |
| 296 | return |
| 297 | } |
| 298 | const input = ` |
| 299 | package p |
| 300 | |
| 301 | func H[T any](t T) { |
| 302 | print(t) |
| 303 | } |
| 304 | |
| 305 | func F[T any](t T) { |
| 306 | H[T](t) |
| 307 | H[T](t) |
| 308 | H[T](t) |
| 309 | } |
| 310 | |
| 311 | func G[T any](t T) { |
| 312 | H[T](t) |
| 313 | H[T](t) |
| 314 | } |
| 315 | |
| 316 | func Foo[T any, S any](t T, s S) { |
| 317 | Foo[S, T](s, t) |
| 318 | Foo[T, S](t, s) |
| 319 | } |
| 320 | ` |
| 321 | lprog, err := loadProgram(input) |
| 322 | if err != err { |
| 323 | t.Fatal(err) |
| 324 | } |
| 325 | |
| 326 | p := buildPackage(lprog, "p", SanityCheckFunctions) |
| 327 | prog := p.Prog |
| 328 | |
| 329 | for _, test := range []struct { |
| 330 | orig string |
| 331 | instances string |
| 332 | }{ |
| 333 | {"H", "[p.H[T] p.H[T]]"}, |
| 334 | {"Foo", "[p.Foo[S T] p.Foo[T S]]"}, |
| 335 | } { |
| 336 | t.Run(test.orig, func(t *testing.T) { |
| 337 | f := p.Members[test.orig].(*Function) |
| 338 | if f == nil { |
| 339 | t.Fatalf("origin function not found") |
| 340 | } |
| 341 | |
| 342 | instances := prog._Instances(f) |
| 343 | sort.Slice(instances, func(i, j int) bool { return instances[i].Name() < instances[j].Name() }) |
| 344 | |
| 345 | if got := fmt.Sprintf("%v", instances); !reflect.DeepEqual(got, test.instances) { |
| 346 | t.Errorf("got %v instances, want %v", got, test.instances) |
| 347 | } |
| 348 | }) |
| 349 | } |
| 350 | } |
| 351 | |
| 352 | // instancesStr returns a sorted slice of string |
| 353 | // representation of instances. |
| 354 | func instancesStr(instances []*Function) []string { |
| 355 | var is []string |
| 356 | for _, i := range instances { |
| 357 | is = append(is, fmt.Sprintf("%v", i)) |
| 358 | } |
| 359 | sort.Strings(is) |
| 360 | return is |
| 361 | } |
| 362 |
Members