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| author | Alan Donovan <adonovan@google.com> | 2024-04-15 14:50:39 -0400 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2024-04-15 19:10:02 +0000 |
| commit | cfbe6cd9bb1595e07ede1ffb1fff610819ffab00 (patch) | |
| tree | adbcd74f35b44daf3cd650d0d3c1bcebbdf0010b /src | |
| parent | b107d95b9a66bfe7150fd4f2915e9bb876a6999a (diff) | |
| download | go-cfbe6cd9bb1595e07ede1ffb1fff610819ffab00.tar.xz | |
cmd/compile/internal/types2: port CL 576975 to types2
This CL ports to types2 the (passing) test from CL 576975,
which fixed a bug in go/types.
Updates #66704
Updates #65294
Change-Id: Icdf77e39ed177d9f9ecc435d5125f02f2ee4dd0f
Reviewed-on: https://go-review.googlesource.com/c/go/+/579015
Auto-Submit: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/types2/api_test.go | 25 | ||||
| -rw-r--r-- | src/cmd/compile/internal/types2/decl.go | 5 |
2 files changed, 30 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/types2/api_test.go b/src/cmd/compile/internal/types2/api_test.go index 008a5302ab..cd979815bf 100644 --- a/src/cmd/compile/internal/types2/api_test.go +++ b/src/cmd/compile/internal/types2/api_test.go @@ -2985,3 +2985,28 @@ func TestTooNew(t *testing.T) { } } } + +// This is a regression test for #66704. +func TestUnaliasTooSoonInCycle(t *testing.T) { + t.Setenv("GODEBUG", "gotypesalias=1") + const src = `package a + +var x T[B] // this appears to cause Unalias to be called on B while still Invalid + +type T[_ any] struct{} +type A T[B] +type B = T[A] +` + + f := mustParse(src) + pkg, err := new(Config).Check("a", []*syntax.File{f}, nil) + if err != nil { + t.Fatal(err) + } + + B := pkg.Scope().Lookup("B") + got, want := Unalias(B.Type()).String(), "a.T[a.A]" + if got != want { + t.Errorf("Unalias(type B = T[A]) = %q, want %q", got, want) + } +} diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go index ed7784a6b8..8bf9c58307 100644 --- a/src/cmd/compile/internal/types2/decl.go +++ b/src/cmd/compile/internal/types2/decl.go @@ -512,6 +512,11 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *TypeN // TODO(gri) Should be able to use nil instead of Typ[Invalid] to mark // the alias as incomplete. Currently this causes problems // with certain cycles. Investigate. + // + // NOTE(adonovan): to avoid the Invalid being prematurely observed + // by (e.g.) a var whose type is an unfinished cycle, + // Unalias does not memoize if Invalid. Perhaps we should use a + // special sentinel distinct from Invalid. alias := check.newAlias(obj, Typ[Invalid]) setDefType(def, alias) |