static HashNumber
HashValue(const Value& v, const mozilla::HashCodeScrambler& hcs)
{
// HashableValue::setValue normalizes values so that the SameValue relation
// on HashableValues is the same as the == relationship on
// value.asRawBits(). So why not just return that? Security.
//
// To avoid revealing GC of atoms, string-based hash codes are computed
// from the string contents rather than any pointer; to avoid revealing
// addresses, pointer-based hash codes are computed using the
// HashCodeScrambler.
if (v.isString())
return v.toString()->asAtom().hash();
if (v.isSymbol()) {
Symbol* sym = v.toSymbol();
if (sym->isWellKnownSymbol())
return HashNumber(sym->code());
if (sym->code() == SymbolCode::InSymbolRegistry)
return sym->description()->hash();
return hcs.scramble(v.asRawBits());
}
if (v.isObject())
return hcs.scramble(v.asRawBits());
MOZ_ASSERT(!v.isGCThing(), "do not reveal pointers via hash codes");
return v.asRawBits();
}
