cmd/gc, reflect, runtime: switch to indirect func value representation
Step 1 of http://golang.org/s/go11func.
R=golang-dev, r, daniel.morsing, remyoudompheng
CC=golang-dev
https://golang.org/cl/7393045
diff --git a/src/pkg/reflect/value.go b/src/pkg/reflect/value.go
index 65311a6..1165975 100644
--- a/src/pkg/reflect/value.go
+++ b/src/pkg/reflect/value.go
@@ -381,7 +381,7 @@
if iface.itab == nil {
panic(method + " of method on nil interface value")
}
- fn = iface.itab.fun[i]
+ fn = unsafe.Pointer(&iface.itab.fun[i])
rcvr = iface.word
} else {
ut := v.typ.uncommon()
@@ -392,7 +392,7 @@
if m.pkgPath != nil {
panic(method + " of unexported method")
}
- fn = m.ifn
+ fn = unsafe.Pointer(&m.ifn)
t = m.mtyp
rcvr = v.iword()
}
@@ -1213,18 +1213,35 @@
// code using reflect cannot obtain unsafe.Pointers
// without importing the unsafe package explicitly.
// It panics if v's Kind is not Chan, Func, Map, Ptr, Slice, or UnsafePointer.
+//
+// If v's Kind is Func, the returned pointer is an underlying
+// code pointer, but not necessarily enough to identify a
+// single function uniquely. The only guarantee is that the
+// result is zero if and only if v is a nil func Value.
func (v Value) Pointer() uintptr {
k := v.kind()
switch k {
- case Chan, Func, Map, Ptr, UnsafePointer:
- if k == Func && v.flag&flagMethod != 0 {
+ case Chan, Map, Ptr, UnsafePointer:
+ p := v.val
+ if v.flag&flagIndir != 0 {
+ p = *(*unsafe.Pointer)(p)
+ }
+ return uintptr(p)
+ case Func:
+ if v.flag&flagMethod != 0 {
panic("reflect.Value.Pointer of method Value")
}
p := v.val
if v.flag&flagIndir != 0 {
p = *(*unsafe.Pointer)(p)
}
+ // Non-nil func value points at data block.
+ // First word of data block is actual code.
+ if p != nil {
+ p = *(*unsafe.Pointer)(p)
+ }
return uintptr(p)
+
case Slice:
return (*SliceHeader)(v.val).Data
}
