diff options
author | Russ Cox <rsc@golang.org> | 2014-04-16 11:52:27 -0400 |
---|---|---|
committer | Russ Cox <rsc@golang.org> | 2014-04-16 11:52:27 -0400 |
commit | 4915d28127c777d7f38eba12d5dba0cffe07745a (patch) | |
tree | 6f446b688af5542ad2f672c91dd4e545ed349736 /src/pkg/reflect/value.go | |
parent | 196470375c518e07451a9d4f0a2f3ecfb10b7e35 (diff) | |
download | go-4915d28127c777d7f38eba12d5dba0cffe07745a.tar.gz |
reflect: correct type descriptor for call of interface method
When preparing a call with an interface method, the argument
frame holds the receiver "iword", but funcLayout was being
asked to write a descriptor as if the receiver were a complete
interface value. This was originally caught by running a large
program with Debug=3 in runtime/mgc0.c, but the new panic
in funcLayout suffices to catch the mistake with the existing
tests.
Fixes issue 7748.
LGTM=bradfitz, iant
R=golang-codereviews, bradfitz, iant
CC=golang-codereviews, khr
https://codereview.appspot.com/88100048
Diffstat (limited to 'src/pkg/reflect/value.go')
-rw-r--r-- | src/pkg/reflect/value.go | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/src/pkg/reflect/value.go b/src/pkg/reflect/value.go index 720090bd6..39cc91991 100644 --- a/src/pkg/reflect/value.go +++ b/src/pkg/reflect/value.go @@ -440,9 +440,8 @@ func (v Value) call(op string, in []Value) []Value { rcvrtype *rtype ) if v.flag&flagMethod != 0 { - rcvrtype = t rcvr = v - t, fn = methodReceiver(op, v, int(v.flag)>>flagMethodShift) + rcvrtype, t, fn = methodReceiver(op, v, int(v.flag)>>flagMethodShift) } else if v.flag&flagIndir != 0 { fn = *(*unsafe.Pointer)(v.ptr) } else { @@ -529,8 +528,7 @@ func (v Value) call(op string, in []Value) []Value { y := (*methodValue)(fn) if y.fn == methodValueCallCode { rcvr = y.rcvr - rcvrtype = rcvr.typ - t, fn = methodReceiver("call", rcvr, y.method) + rcvrtype, t, fn = methodReceiver("call", rcvr, y.method) } // Compute frame type, allocate a chunk of memory for frame @@ -668,9 +666,10 @@ func callReflect(ctxt *makeFuncImpl, frame unsafe.Pointer) { // described by v. The Value v may or may not have the // flagMethod bit set, so the kind cached in v.flag should // not be used. +// The return value rcvrtype gives the method's actual receiver type. // The return value t gives the method type signature (without the receiver). // The return value fn is a pointer to the method code. -func methodReceiver(op string, v Value, methodIndex int) (t *rtype, fn unsafe.Pointer) { +func methodReceiver(op string, v Value, methodIndex int) (rcvrtype, t *rtype, fn unsafe.Pointer) { i := methodIndex if v.typ.Kind() == Interface { tt := (*interfaceType)(unsafe.Pointer(v.typ)) @@ -685,9 +684,11 @@ func methodReceiver(op string, v Value, methodIndex int) (t *rtype, fn unsafe.Po if iface.itab == nil { panic("reflect: " + op + " of method on nil interface value") } + rcvrtype = iface.itab.typ fn = unsafe.Pointer(&iface.itab.fun[i]) t = m.typ } else { + rcvrtype = v.typ ut := v.typ.uncommon() if ut == nil || i < 0 || i >= len(ut.methods) { panic("reflect: internal error: invalid method index") @@ -746,8 +747,7 @@ func align(x, n uintptr) uintptr { // The gc compilers know to do that for the name "reflect.callMethod". func callMethod(ctxt *methodValue, frame unsafe.Pointer) { rcvr := ctxt.rcvr - rcvrtype := rcvr.typ - t, fn := methodReceiver("call", rcvr, ctxt.method) + rcvrtype, t, fn := methodReceiver("call", rcvr, ctxt.method) frametype, argSize, retOffset := funcLayout(t, rcvrtype) // Make a new frame that is one word bigger so we can store the receiver. |