// genConv generates constraints for the conversion operation conv.
func (a *analysis) genConv(conv *ssa.Convert, cgn *cgnode) {
res := a.valueNode(conv)
if res == 0 {
return // result is non-pointerlike
}
tSrc := conv.X.Type()
tDst := conv.Type()
switch utSrc := tSrc.Underlying().(type) {
case *types.Slice:
// []byte/[]rune -> string?
return
case *types.Pointer:
// *T -> unsafe.Pointer?
if tDst.Underlying() == tUnsafePtr {
return // we don't model unsafe aliasing (unsound)
}
case *types.Basic:
switch tDst.Underlying().(type) {
case *types.Pointer:
// Treat unsafe.Pointer->*T conversions like
// new(T) and create an unaliased object.
if utSrc == tUnsafePtr {
obj := a.addNodes(mustDeref(tDst), "unsafe.Pointer conversion")
a.endObject(obj, cgn, conv)
a.addressOf(tDst, res, obj)
return
}
case *types.Slice:
// string -> []byte/[]rune (or named aliases)?
if utSrc.Info()&types.IsString != 0 {
obj := a.addNodes(sliceToArray(tDst), "convert")
a.endObject(obj, cgn, conv)
a.addressOf(tDst, res, obj)
return
}
case *types.Basic:
// All basic-to-basic type conversions are no-ops.
// This includes uintptr<->unsafe.Pointer conversions,
// which we (unsoundly) ignore.
return
}
}
panic(fmt.Sprintf("illegal *ssa.Convert %s -> %s: %s", tSrc, tDst, conv.Parent()))
}
