func decodetypeGcprogShlib(ctxt *Link, data []byte) uint64 {
	return decodeInuxi(ctxt.Arch, data[2*int32(ctxt.Arch.PtrSize)+8+1*int32(ctxt.Arch.PtrSize):], ctxt.Arch.PtrSize)
}

// decodeItabType returns the itab.Type field from an itab.
func decodeItabType(ldr *loader.Loader, arch *sys.Arch, symIdx loader.Sym) loader.Sym {
	relocs := ldr.Relocs(symIdx)
	return decodeRelocSym(ldr, symIdx, &relocs, int32(abi.ITabTypeOff(arch.PtrSize)))

		var itab *ir.AddrExpr
		if typ.IsEmptyInterface() {
			itab = reflectdata.TypePtrAt(base.Pos, val.Type())
		} else {
			itab = reflectdata.ITabAddrAt(base.Pos, val.Type(), typ)
		}

		// Create a copy of l to modify while we emit data.

		// Emit itab, advance offset.
		staticdata.InitAddr(l, loff, itab.X.(*ir.LinksymOffsetExpr).Linksym)

		// Emit data.

	//   c. at least one is a gcshape type.
	// For assignable but different non-empty interface types,
	// we want to recompute the itab. Recomputing the itab ensures
	// that itabs are unique (thus an interface with a compile-time
	// type I has an itab with interface type I).
	if types.Identical(src.Underlying(), dst.Underlying()) {
		if src.IsEmptyInterface() {
			// Conversion between two empty interfaces

# fields to python attributes in gdb.py isn't complete: you can't test
# for presence other than by trapping.


def is_iface(val):
	try:
		return str(val['tab'].type) == "struct runtime.itab *" and str(val['data'].type) == "void *"
	except gdb.error:
		pass


def is_eface(val):
	try:
		return str(val['_type'].type) == "struct runtime._type *" and str(val['data'].type) == "void *"

// walkDynamicDotType walks an ODYNAMICDOTTYPE or ODYNAMICDOTTYPE2 node.
func walkDynamicDotType(n *ir.DynamicTypeAssertExpr, init *ir.Nodes) ir.Node {
	n.X = walkExpr(n.X, init)
	n.RType = walkExpr(n.RType, init)
	n.ITab = walkExpr(n.ITab, init)
	// Convert to non-dynamic if we can.
	if n.RType != nil && n.RType.Op() == ir.OADDR {
		addr := n.RType.(*ir.AddrExpr)
		if addr.X.Op() == ir.OLINKSYMOFFSET {

	case fint.Kind_&abi.KindMask == abi.Interface:
		ityp := (*interfacetype)(unsafe.Pointer(fint))
		if len(ityp.Methods) == 0 {
			// ok - satisfies empty interface
			goto okarg
		}
		if itab := assertE2I2(ityp, efaceOf(&obj)._type); itab != nil {
			goto okarg
		}
	}
	throw("runtime.SetFinalizer: cannot pass " + toRType(etyp).string() + " to finalizer " + toRType(ftyp).string())
okarg:

	lockRankSudog:           "sudog",
	lockRankTimers:          "timers",
	lockRankTimer:           "timer",
	lockRankNetpollInit:     "netpollInit",
	lockRankRoot:            "root",
	lockRankItab:            "itab",
	lockRankReflectOffs:     "reflectOffs",
	lockRankUserArenaState:  "userArenaState",
	lockRankTraceBuf:        "traceBuf",
	lockRankTraceStrings:    "traceStrings",
	lockRankFin:             "fin",

	R_USETYPE
	// R_USEIFACE marks a type is converted to an interface in the function this
	// relocation is applied to. The target is a type descriptor or an itab
	// (in the latter case it refers to the concrete type contained in the itab).
	// This is a marker relocation (0-sized), for the linker's reachabililty
	// analysis.
	R_USEIFACE
	// R_USEIFACEMETHOD marks an interface method that is used in the function

# Channels
NONE < notifyList;
hchan, notifyList < sudog;

hchan, pollDesc, wakeableSleep < timers;
timers, timerSend < timer < netpollInit;

# Semaphores
NONE < root;

# Itabs
NONE
< itab
< reflectOffs;

# User arena state
NONE < userArenaState;

# Tracing without a P uses a global trace buffer.
scavenge
# Above TRACEGLOBAL can emit a trace event without a P.
< TRACEGLOBAL

func panicnildottype(want *byte)
func typeAssert(s *byte, typ *byte) *byte

// interface switches
func interfaceSwitch(s *byte, t *byte) (int, *byte)

// interface equality. Type/itab pointers are already known to be equal, so
// we only need to pass one.
func ifaceeq(tab *uintptr, x, y unsafe.Pointer) (ret bool)
func efaceeq(typ *uintptr, x, y unsafe.Pointer) (ret bool)