From bd4dc413cd80d3c160e875686e1be1eae5d48d4b Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Wed, 22 Oct 2025 10:13:44 -0700 Subject: [PATCH] cmd/compile: don't optimize away a panicing interface comparison We can't do direct pointer comparisons if the type is not a comparable type. Fixes #76008 Change-Id: I1687acff21832d2c2e8f3b875e7b5ec125702ef3 Reviewed-on: https://go-review.googlesource.com/c/go/+/713840 LUCI-TryBot-Result: Go LUCI Reviewed-by: David Chase Reviewed-by: Cuong Manh Le Reviewed-by: Keith Randall --- src/cmd/compile/internal/ssa/rewrite.go | 10 ++++--- test/fixedbugs/issue76008.go | 35 +++++++++++++++++++++++++ 2 files changed, 41 insertions(+), 4 deletions(-) create mode 100644 test/fixedbugs/issue76008.go diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go index 16c28e1ea4..2856ff2e43 100644 --- a/src/cmd/compile/internal/ssa/rewrite.go +++ b/src/cmd/compile/internal/ssa/rewrite.go @@ -2626,7 +2626,7 @@ func rewriteStructStore(v *Value) *Value { // isDirectType reports whether v represents a type // (a *runtime._type) whose value is stored directly in an -// interface (i.e., is pointer or pointer-like). +// interface (i.e., is pointer or pointer-like) and is comparable. func isDirectType(v *Value) bool { return isDirectType1(v) } @@ -2639,7 +2639,8 @@ func isDirectType1(v *Value) bool { case OpAddr: lsym := v.Aux.(*obj.LSym) if ti := lsym.TypeInfo(); ti != nil { - return types.IsDirectIface(ti.Type.(*types.Type)) + t := ti.Type.(*types.Type) + return types.IsDirectIface(t) && types.IsComparable(t) } } return false @@ -2656,7 +2657,7 @@ func isDirectType2(v *Value) bool { // isDirectIface reports whether v represents an itab // (a *runtime._itab) for a type whose value is stored directly -// in an interface (i.e., is pointer or pointer-like). +// in an interface (i.e., is pointer or pointer-like) and is comparable. func isDirectIface(v *Value) bool { return isDirectIface1(v, 9) } @@ -2672,7 +2673,8 @@ func isDirectIface1(v *Value, depth int) bool { case OpAddr: lsym := v.Aux.(*obj.LSym) if ii := lsym.ItabInfo(); ii != nil { - return types.IsDirectIface(ii.Type.(*types.Type)) + t := ii.Type.(*types.Type) + return types.IsDirectIface(t) && types.IsComparable(t) } case OpConstNil: // We can treat this as direct, because if the itab is diff --git a/test/fixedbugs/issue76008.go b/test/fixedbugs/issue76008.go new file mode 100644 index 0000000000..bdf273bca1 --- /dev/null +++ b/test/fixedbugs/issue76008.go @@ -0,0 +1,35 @@ +// run + +// Copyright 2025 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 + +import "runtime" + +func main() { + shouldPanic(func() { + g = any(func() {}) == any(func() {}) + }) + shouldPanic(func() { + g = any(map[int]int{}) == any(map[int]int{}) + }) + shouldPanic(func() { + g = any([]int{}) == any([]int{}) + }) +} + +var g bool + +func shouldPanic(f func()) { + defer func() { + err := recover() + if err == nil { + _, _, line, _ := runtime.Caller(2) + println("did not panic at line", line+1) + } + }() + + f() +} -- 2.52.0