From ca634fa2c550cd85a1a2cc03c208304ee38c6a82 Mon Sep 17 00:00:00 2001 From: Matthew Dempsky Date: Wed, 31 Aug 2022 15:48:35 -0700 Subject: cmd/compile: reject not-in-heap types as type arguments After running the types2 type checker, walk info.Instances to reject any not-in-heap type arguments. This is feasible to check using the types2 API now, thanks to #46731. Fixes #54765. Change-Id: Idd2acc124d102d5a76f128f13c21a6e593b6790b Reviewed-on: https://go-review.googlesource.com/c/go/+/427235 Reviewed-by: Keith Randall TryBot-Result: Gopher Robot Auto-Submit: Matthew Dempsky Run-TryBot: Matthew Dempsky Reviewed-by: Keith Randall --- src/cmd/compile/internal/noder/helpers.go | 25 +++++++++++++++++++++++++ src/cmd/compile/internal/noder/irgen.go | 26 ++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) (limited to 'src/cmd/compile/internal/noder') diff --git a/src/cmd/compile/internal/noder/helpers.go b/src/cmd/compile/internal/noder/helpers.go index 4c9c6f6cc9..764dcb3f85 100644 --- a/src/cmd/compile/internal/noder/helpers.go +++ b/src/cmd/compile/internal/noder/helpers.go @@ -256,3 +256,28 @@ func isTypeParam(t types2.Type) bool { _, ok := t.(*types2.TypeParam) return ok } + +// isNotInHeap reports whether typ is or contains an element of type +// runtime/internal/sys.NotInHeap. +func isNotInHeap(typ types2.Type) bool { + if named, ok := typ.(*types2.Named); ok { + if obj := named.Obj(); obj.Name() == "nih" && obj.Pkg().Path() == "runtime/internal/sys" { + return true + } + typ = named.Underlying() + } + + switch typ := typ.(type) { + case *types2.Array: + return isNotInHeap(typ.Elem()) + case *types2.Struct: + for i := 0; i < typ.NumFields(); i++ { + if isNotInHeap(typ.Field(i).Type()) { + return true + } + } + return false + default: + return false + } +} diff --git a/src/cmd/compile/internal/noder/irgen.go b/src/cmd/compile/internal/noder/irgen.go index ad937eac62..dc69e94924 100644 --- a/src/cmd/compile/internal/noder/irgen.go +++ b/src/cmd/compile/internal/noder/irgen.go @@ -6,6 +6,7 @@ package noder import ( "fmt" + "sort" "cmd/compile/internal/base" "cmd/compile/internal/dwarfgen" @@ -63,6 +64,31 @@ func checkFiles(noders []*noder) (posMap, *types2.Package, *types2.Info) { pkg, err := conf.Check(base.Ctxt.Pkgpath, files, info) + // Implementation restriction: we don't allow not-in-heap types to + // be used as type arguments (#54765). + { + type nihTarg struct { + pos src.XPos + typ types2.Type + } + var nihTargs []nihTarg + + for name, inst := range info.Instances { + for i := 0; i < inst.TypeArgs.Len(); i++ { + if targ := inst.TypeArgs.At(i); isNotInHeap(targ) { + nihTargs = append(nihTargs, nihTarg{m.makeXPos(name.Pos()), targ}) + } + } + } + sort.Slice(nihTargs, func(i, j int) bool { + ti, tj := nihTargs[i], nihTargs[j] + return ti.pos.Before(tj.pos) + }) + for _, targ := range nihTargs { + base.ErrorfAt(targ.pos, "cannot use incomplete (or unallocatable) type as a type argument: %v", targ.typ) + } + } + base.ExitIfErrors() if err != nil { base.FatalfAt(src.NoXPos, "conf.Check error: %v", err) -- cgit v1.3-5-g9baa