The checkBuiltinArgument helper takes an integer ArgIndex and is
documented as performing normal type-checking on that argument. However,
it mistakenly hardcodes the argument index to zero when retrieving the
argument from the call expression.
This hadn't been noticed previously as all in-tree uses typecheck the
0th argument anyway.
InitializedEntity Entity =
InitializedEntity::InitializeParameter(S.Context, Param);
- ExprResult Arg = E->getArg(0);
+ ExprResult Arg = E->getArg(ArgIndex);
Arg = S.PerformCopyInitialization(Entity, SourceLocation(), Arg);
if (Arg.isInvalid())
return true;