reflect: handling flagIndir in DeepEqual potential cycles
Fixes #39607
Change-Id: Ia7e597e0da8a193a25382cc633a1c6080b4f7cbf
Reviewed-on: https://go-review.googlesource.com/c/go/+/238361
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index e87d1d2..63f6a92 100644
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -824,6 +824,11 @@
var loopy1, loopy2 Loopy
var cycleMap1, cycleMap2, cycleMap3 map[string]interface{}
+type structWithSelfPtr struct {
+ p *structWithSelfPtr
+ s string
+}
+
func init() {
loop1 = &loop2
loop2 = &loop1
@@ -880,6 +885,7 @@
{[]float64{math.NaN()}, self{}, true},
{map[float64]float64{math.NaN(): 1}, map[float64]float64{1: 2}, false},
{map[float64]float64{math.NaN(): 1}, self{}, true},
+ {&structWithSelfPtr{p: &structWithSelfPtr{s: "a"}}, &structWithSelfPtr{p: &structWithSelfPtr{s: "b"}}, false},
// Nil vs empty: not the same.
{[]int{}, []int(nil), false},
diff --git a/src/reflect/deepequal.go b/src/reflect/deepequal.go
index f2d4616..8a2bf8b 100644
--- a/src/reflect/deepequal.go
+++ b/src/reflect/deepequal.go
@@ -45,8 +45,20 @@
}
if hard(v1, v2) {
- addr1 := v1.ptr
- addr2 := v2.ptr
+ // For a Ptr or Map value, we need to check flagIndir,
+ // which we do by calling the pointer method.
+ // For Slice or Interface, flagIndir is always set,
+ // and using v.ptr suffices.
+ ptrval := func(v Value) unsafe.Pointer {
+ switch v.Kind() {
+ case Ptr, Map:
+ return v.pointer()
+ default:
+ return v.ptr
+ }
+ }
+ addr1 := ptrval(v1)
+ addr2 := ptrval(v2)
if uintptr(addr1) > uintptr(addr2) {
// Canonicalize order to reduce number of entries in visited.
// Assumes non-moving garbage collector.
