undo CL 14154043 / 3e485428767e

««« original CL description
encoding/gob: do not hide pointer argument for the garbage collector

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/14154043
»»»

R=golang-dev
CC=golang-dev
https://golang.org/cl/14165043

diff --git a/src/pkg/encoding/gob/decode.go b/src/pkg/encoding/gob/decode.go
index 5665dd12d774c6139f4bdf0034dd3fae648a7f58..3e76f4c9066b146b7baa2111031873732907d1cd 100644 (file)
--- a/src/pkg/encoding/gob/decode.go
+++ b/src/pkg/encoding/gob/decode.go
@@ -654,19 +654,21 @@ func (dec *Decoder) ignoreMap(state *decoderState, keyOp, elemOp decOp) {
 
 // decodeSlice decodes a slice and stores the slice header through p.
 // Slices are encoded as an unsigned length followed by the elements.
-func (dec *Decoder) decodeSlice(atyp reflect.Type, state *decoderState, p unsafe.Pointer, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl error) {
+func (dec *Decoder) decodeSlice(atyp reflect.Type, state *decoderState, p uintptr, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl error) {
        nr := state.decodeUint()
        n := int(nr)
        if indir > 0 {
-               if *(*unsafe.Pointer)(p) == nil {
+               up := unsafe.Pointer(p)
+               if *(*unsafe.Pointer)(up) == nil {
                        // Allocate the slice header.
-                       *(*unsafe.Pointer)(p) = unsafe.Pointer(new([]unsafe.Pointer))
+                       *(*unsafe.Pointer)(up) = unsafe.Pointer(new([]unsafe.Pointer))
                }
+               p = *(*uintptr)(up)
        }
        // Allocate storage for the slice elements, that is, the underlying array,
        // if the existing slice does not have the capacity.
        // Always write a header at p.
-       hdrp := (*reflect.SliceHeader)(p)
+       hdrp := (*reflect.SliceHeader)(unsafe.Pointer(p))
        if hdrp.Cap < n {
                hdrp.Data = reflect.MakeSlice(atyp, n, n).Pointer()
                hdrp.Cap = n
@@ -885,7 +887,7 @@ func (dec *Decoder) decOpFor(wireId typeId, rt reflect.Type, name string, inProg
                        elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress)
                        ovfl := overflow(name)
                        op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
-                               state.dec.decodeSlice(t, state, p, *elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl)
+                               state.dec.decodeSlice(t, state, uintptr(p), *elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl)
                        }
 
                case reflect.Struct: