Flags       FuncPropBits
	ParamFlags  []ParamPropBits // slot 0 receiver if applicable
	ResultFlags []ResultPropBits
}

type FuncPropBits uint32

const (
	// Function always panics or invokes os.Exit() or a func that does
	// likewise.
	FuncPropNeverReturns FuncPropBits = 1 << iota
)

type ParamPropBits uint32

const (
	// No info about this param
	ParamNoInfo ParamPropBits = 0

	var v uint64
	sl := []byte(s)
	v, sl = readULEB128(sl)
	funcProps.Flags = FuncPropBits(v)
	v, sl = readULEB128(sl)
	funcProps.ParamFlags = make([]ParamPropBits, v)
	for i := range funcProps.ParamFlags {
		v, sl = readULEB128(sl)
		funcProps.ParamFlags[i] = ParamPropBits(v)
	}
	v, sl = readULEB128(sl)
	funcProps.ResultFlags = make([]ResultPropBits, v)
	for i := range funcProps.ResultFlags {
		v, sl = readULEB128(sl)

	return fp.ToString("")
}

func (fp *FuncProps) ToString(prefix string) string {
	var sb strings.Builder
	if fp.Flags != 0 {
		fmt.Fprintf(&sb, "%sFlags %s\n", prefix, fp.Flags)
	}
	flagSliceToSB[ParamPropBits](&sb, fp.ParamFlags,
		prefix, "ParamFlags")
	flagSliceToSB[ResultPropBits](&sb, fp.ResultFlags,
		prefix, "ResultFlags")
	return sb.String()
}

func flagSliceToSB[T interface {
	~uint32
	String() string

	if rgot != rwant {
		t.Errorf("testcase %q: Results mismatch for %q: got:\n%swant:\n%s",
			tc, dfn, rgot, rwant)
	}
	// Compare receiver + params.
	pgot := propBitsToString[ParamPropBits](dfp.ParamFlags)
	pwant := propBitsToString[ParamPropBits](efp.ParamFlags)
	if pgot != pwant {
		t.Errorf("testcase %q: Params mismatch for %q: got:\n%swant:\n%s",
			tc, dfn, pgot, pwant)
	}
	// Compare call sites.

var paramFlagToPositiveAdj map[ParamPropBits]scoreAdjustTyp

func setupFlagToAdjMaps() {
	resultFlagToPositiveAdj = map[ResultPropBits]scoreAdjustTyp{
		ResultIsAllocatedMem:     returnFeedsConcreteToInterfaceCallAdj,
		ResultAlwaysSameFunc:     returnFeedsFuncToIndCallAdj,
		ResultAlwaysSameConstant: returnFeedsConstToIfAdj,
	}
	paramFlagToPositiveAdj = map[ParamPropBits]scoreAdjustTyp{