Rename args to check_argument_types and add some comments for what they are

This commit is contained in:
Jack Huey 2021-12-24 14:31:17 -05:00
parent e100ec5bc7
commit 9a38ed12ca

View File

@ -96,34 +96,43 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
/// method calls and overloaded operators.
pub(in super::super) fn check_argument_types(
&self,
sp: Span,
expr: &'tcx hir::Expr<'tcx>,
fn_inputs: &[Ty<'tcx>],
expected_arg_tys: &[Ty<'tcx>],
args: &'tcx [hir::Expr<'tcx>],
// Span enclosing the call site
call_span: Span,
// Expression of the call site
call_expr: &'tcx hir::Expr<'tcx>,
// Types (as defined in the *signature* of the target function)
formal_input_tys: &[Ty<'tcx>],
// More specific expected types, after unifying with caller output types
expected_input_tys: &[Ty<'tcx>],
// The expressions for each provided argument
provided_args: &'tcx [hir::Expr<'tcx>],
// Whether the function is variadic, for example when imported from C
c_variadic: bool,
// Whether the arguments have been bundled in a tuple (ex: closures)
tuple_arguments: TupleArgumentsFlag,
def_id: Option<DefId>,
// The DefId for the function being called, for better error messages
fn_def_id: Option<DefId>,
) {
let tcx = self.tcx;
// Grab the argument types, supplying fresh type variables
// if the wrong number of arguments were supplied
let supplied_arg_count = if tuple_arguments == DontTupleArguments { args.len() } else { 1 };
let supplied_arg_count =
if tuple_arguments == DontTupleArguments { provided_args.len() } else { 1 };
// All the input types from the fn signature must outlive the call
// so as to validate implied bounds.
for (&fn_input_ty, arg_expr) in iter::zip(fn_inputs, args) {
for (&fn_input_ty, arg_expr) in iter::zip(formal_input_tys, provided_args) {
self.register_wf_obligation(fn_input_ty.into(), arg_expr.span, traits::MiscObligation);
}
let expected_arg_count = fn_inputs.len();
let expected_arg_count = formal_input_tys.len();
let param_count_error = |expected_count: usize,
arg_count: usize,
error_code: &str,
c_variadic: bool,
sugg_unit: bool| {
let (span, start_span, args, ctor_of) = match &expr.kind {
let (span, start_span, args, ctor_of) = match &call_expr.kind {
hir::ExprKind::Call(
hir::Expr {
span,
@ -156,14 +165,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
&args[1..], // Skip the receiver.
None, // methods are never ctors
),
k => span_bug!(sp, "checking argument types on a non-call: `{:?}`", k),
k => span_bug!(call_span, "checking argument types on a non-call: `{:?}`", k),
};
let arg_spans = if args.is_empty() {
let arg_spans = if provided_args.is_empty() {
// foo()
// ^^^-- supplied 0 arguments
// |
// expected 2 arguments
vec![tcx.sess.source_map().next_point(start_span).with_hi(sp.hi())]
vec![tcx.sess.source_map().next_point(start_span).with_hi(call_span.hi())]
} else {
// foo(1, 2, 3)
// ^^^ - - - supplied 3 arguments
@ -196,7 +205,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
);
}
if let Some(def_id) = def_id {
if let Some(def_id) = fn_def_id {
if let Some(def_span) = tcx.def_ident_span(def_id) {
let mut spans: MultiSpan = def_span.into();
@ -218,7 +227,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
if sugg_unit {
let sugg_span = tcx.sess.source_map().end_point(expr.span);
let sugg_span = tcx.sess.source_map().end_point(call_expr.span);
// remove closing `)` from the span
let sugg_span = sugg_span.shrink_to_lo();
err.span_suggestion(
@ -240,15 +249,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
err.emit();
};
let mut expected_arg_tys = expected_arg_tys.to_vec();
let mut expected_arg_tys = expected_input_tys.to_vec();
let formal_tys = if tuple_arguments == TupleArguments {
let tuple_type = self.structurally_resolved_type(sp, fn_inputs[0]);
let tuple_type = self.structurally_resolved_type(call_span, formal_input_tys[0]);
match tuple_type.kind() {
ty::Tuple(arg_types) if arg_types.len() != args.len() => {
param_count_error(arg_types.len(), args.len(), "E0057", false, false);
ty::Tuple(arg_types) if arg_types.len() != provided_args.len() => {
param_count_error(arg_types.len(), provided_args.len(), "E0057", false, false);
expected_arg_tys = vec![];
self.err_args(args.len())
self.err_args(provided_args.len())
}
ty::Tuple(arg_types) => {
expected_arg_tys = match expected_arg_tys.get(0) {
@ -263,21 +272,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
_ => {
struct_span_err!(
tcx.sess,
sp,
call_span,
E0059,
"cannot use call notation; the first type parameter \
for the function trait is neither a tuple nor unit"
)
.emit();
expected_arg_tys = vec![];
self.err_args(args.len())
self.err_args(provided_args.len())
}
}
} else if expected_arg_count == supplied_arg_count {
fn_inputs.to_vec()
formal_input_tys.to_vec()
} else if c_variadic {
if supplied_arg_count >= expected_arg_count {
fn_inputs.to_vec()
formal_input_tys.to_vec()
} else {
param_count_error(expected_arg_count, supplied_arg_count, "E0060", true, false);
expected_arg_tys = vec![];
@ -287,8 +296,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// is the missing argument of type `()`?
let sugg_unit = if expected_arg_tys.len() == 1 && supplied_arg_count == 0 {
self.resolve_vars_if_possible(expected_arg_tys[0]).is_unit()
} else if fn_inputs.len() == 1 && supplied_arg_count == 0 {
self.resolve_vars_if_possible(fn_inputs[0]).is_unit()
} else if formal_input_tys.len() == 1 && supplied_arg_count == 0 {
self.resolve_vars_if_possible(formal_input_tys[0]).is_unit()
} else {
false
};
@ -322,13 +331,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// the call. This helps coercions.
if check_closures {
self.select_obligations_where_possible(false, |errors| {
self.point_at_type_arg_instead_of_call_if_possible(errors, expr);
self.point_at_type_arg_instead_of_call_if_possible(errors, call_expr);
self.point_at_arg_instead_of_call_if_possible(
errors,
&final_arg_types,
expr,
sp,
&args,
call_expr,
call_span,
&provided_args,
);
})
}
@ -339,11 +348,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let t = if c_variadic {
expected_arg_count
} else if tuple_arguments == TupleArguments {
args.len()
provided_args.len()
} else {
supplied_arg_count
};
for (i, arg) in args.iter().take(t).enumerate() {
for (i, arg) in provided_args.iter().take(t).enumerate() {
// Warn only for the first loop (the "no closures" one).
// Closure arguments themselves can't be diverging, but
// a previous argument can, e.g., `foo(panic!(), || {})`.
@ -380,13 +389,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let _ = self.resolve_vars_with_obligations_and_mutate_fulfillment(
coerce_ty,
|errors| {
self.point_at_type_arg_instead_of_call_if_possible(errors, expr);
self.point_at_type_arg_instead_of_call_if_possible(errors, call_expr);
self.point_at_arg_instead_of_call_if_possible(
errors,
&final_arg_types,
expr,
sp,
args,
call_expr,
call_span,
provided_args,
);
},
);
@ -410,7 +419,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
MissingCastForVariadicArg { sess, span, ty, cast_ty }.diagnostic().emit()
}
for arg in args.iter().skip(expected_arg_count) {
for arg in provided_args.iter().skip(expected_arg_count) {
let arg_ty = self.check_expr(&arg);
// There are a few types which get autopromoted when passed via varargs