diff --git a/src/cmd/compile/internal/ssa/copyelim.go b/src/cmd/compile/internal/ssa/copyelim.go index 17f65127ee..17471e3b5f 100644 --- a/src/cmd/compile/internal/ssa/copyelim.go +++ b/src/cmd/compile/internal/ssa/copyelim.go @@ -11,6 +11,17 @@ func copyelim(f *Func) { // of OpCopy) is a copy. for _, b := range f.Blocks { for _, v := range b.Values { + + // This is an early place in SSA where all values are examined. + // Rewrite all 0-sized Go values to remove accessors, dereferences, loads, etc. + if t := v.Type; (t.IsStruct() || t.IsArray()) && t.Size() == 0 { + if t.IsStruct() { + v.reset(OpStructMake0) + } else { + v.reset(OpArrayMake0) + } + } + copyelimValue(v) } } diff --git a/test/fixedbugs/issue65808.go b/test/fixedbugs/issue65808.go new file mode 100644 index 0000000000..e6c4cf1ed0 --- /dev/null +++ b/test/fixedbugs/issue65808.go @@ -0,0 +1,30 @@ +// compile + +// Copyright 2024 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 main + +package main + +type Stringer interface { + String() string +} + +type ( + stringer struct{} + stringers [2]stringer + foo struct { + stringers + } +) + +func (stringer) String() string { return "" } +func toString(s Stringer) string { return s.String() } + +func (v stringers) toStrings() []string { + return []string{toString(v[0]), toString(v[1])} +} + +func main() { + _ = stringers{} +}