diff options
author | Robert Griesemer <gri@golang.org> | 2021-08-17 11:45:05 -0700 |
---|---|---|
committer | Robert Griesemer <gri@golang.org> | 2021-08-17 20:57:49 +0000 |
commit | 9d9e3291faee4b01165247956e8555eb1bb291f1 (patch) | |
tree | 358e204f790dc3f2bd6d2be7ed1ce0655c82503f /src/cmd/compile/internal | |
parent | cf12b0d1f96242eefbe64dbf449f30cce2756560 (diff) | |
download | go-9d9e3291faee4b01165247956e8555eb1bb291f1.tar.gz go-9d9e3291faee4b01165247956e8555eb1bb291f1.zip |
cmd/compile/internal/types2: fix method lookup for type-parameter based types
Pointers to type parameters don't have methods, but pointers to
defined types whose underlying types are type parameters may have
methods. Fix the respective test.
For #47747.
Change-Id: I1de47be094ed9297f0e7782538011657c37c5adc
Reviewed-on: https://go-review.googlesource.com/c/go/+/342990
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Diffstat (limited to 'src/cmd/compile/internal')
-rw-r--r-- | src/cmd/compile/internal/types2/lookup.go | 9 | ||||
-rw-r--r-- | src/cmd/compile/internal/types2/testdata/fixedbugs/issue47747.go2 | 68 |
2 files changed, 74 insertions, 3 deletions
diff --git a/src/cmd/compile/internal/types2/lookup.go b/src/cmd/compile/internal/types2/lookup.go index 3779d17b3d..668c5ff3ec 100644 --- a/src/cmd/compile/internal/types2/lookup.go +++ b/src/cmd/compile/internal/types2/lookup.go @@ -74,9 +74,12 @@ func lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (o typ, isPtr := deref(T) // *typ where typ is an interface or type parameter has no methods. - switch under(typ).(type) { - case *Interface, *TypeParam: - if isPtr { + if isPtr { + // don't look at under(typ) here - was bug (issue #47747) + if _, ok := typ.(*TypeParam); ok { + return + } + if _, ok := under(typ).(*Interface); ok { return } } diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47747.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47747.go2 new file mode 100644 index 0000000000..af52056bef --- /dev/null +++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47747.go2 @@ -0,0 +1,68 @@ +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package p + +type T1[P any] P + +func (T1[_]) m() {} + +func _[P any](x *T1[P]) { + // x.m exists because x is of type *T1 where T1 is a defined type + // (even though under(T1) is a type parameter) + x.m() +} + + +func _[P interface{ m() }](x P) { + x.m() + // (&x).m doesn't exist because &x is of type *P + // and pointers to type parameters don't have methods + (&x).m /* ERROR \*P has no field or method m */ () +} + + +type T2 interface{ m() } + +func _(x *T2) { + // x.m doesn't exists because x is of type *T2 + // and pointers to interfaces don't have methods + x.m /* ERROR \*T2 has no field or method m */() +} + +// Test case 1 from issue + +type Fooer1[t any] interface { + Foo(Barer[t]) +} +type Barer[t any] interface { + Bar(t) +} + +type Foo1[t any] t +type Bar[t any] t + +func (l Foo1[t]) Foo(v Barer[t]) { v.Bar(t(l)) } +func (b *Bar[t]) Bar(l t) { *b = Bar[t](l) } + +func _[t any](f Fooer1[t]) t { + var b Bar[t] + f.Foo(&b) + return t(b) +} + +// Test case 2 from issue + +type Fooer2[t any] interface { + Foo() +} + +type Foo2[t any] t + +func (f *Foo2[t]) Foo() {} + +func _[t any](v t) { + var f = Foo2[t](v) + _ = Fooer2[t](&f) +} |