Check extra function arg exprs even if the fn is not C-variadic

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -281,6 +281,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
  self.demand_suptype(provided_arg.span, formal_input_ty, coerced_ty);
  };
 
+ let minimum_input_count = formal_input_tys.len();
+
  // Check the arguments.
  // We do this in a pretty awful way: first we type-check any arguments
  // that are not closures, then we type-check the closures. This is so
@@ -303,7 +305,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
  })
  }
 
- let minimum_input_count = formal_input_tys.len();
  for (idx, arg) in provided_args.iter().enumerate() {
  // Warn only for the first loop (the "no closures" one).
  // Closure arguments themselves can't be diverging, but
@@ -456,17 +457,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
  err.emit();
  }
 
- // We also need to make sure we at least write the ty of the other
- // arguments which we skipped above.
- if c_variadic {
- fn variadic_error<'tcx>(sess: &Session, span: Span, ty: Ty<'tcx>, cast_ty: &str) {
- use crate::structured_errors::MissingCastForVariadicArg;
+ for arg in provided_args.iter().skip(minimum_input_count) {
+ let arg_ty = self.check_expr(&arg);
 
- MissingCastForVariadicArg { sess, span, ty, cast_ty }.diagnostic().emit();
- }
+ if c_variadic {
+ // We also need to make sure we at least write the ty of the other
+ // arguments which we skipped above, either because they were additional
+ // c_variadic args, or because we had an argument count mismatch.
+ fn variadic_error<'tcx>(sess: &Session, span: Span, ty: Ty<'tcx>, cast_ty: &str) {
+ use crate::structured_errors::MissingCastForVariadicArg;
 
- for arg in provided_args.iter().skip(expected_arg_count) {
- let arg_ty = self.check_expr(&arg);
+  MissingCastForVariadicArg { sess, span, ty, cast_ty }.diagnostic().emit();
+ }
 
  // There are a few types which get autopromoted when passed via varargs
  // in C but we just error out instead and require explicit casts.

src/test/ui/tuple/wrong_argument_ice-4.rs

@@ -0,0 +1,6 @@
+fn main() {
+ (|| {})(|| {
+ //~^ ERROR this function takes 0 arguments but 1 argument was supplied
+ let b = 1;
+ });
+}

src/test/ui/tuple/wrong_argument_ice-4.stderr

@@ -0,0 +1,15 @@
+error[E0057]: this function takes 0 arguments but 1 argument was supplied
+ --> $DIR/wrong_argument_ice-4.rs:2:5
+ |
+LL | (|| {})(|| {
+ | _____^^^^^^^_-
+ | | |
+ | | expected 0 arguments
+LL | |
+LL | | let b = 1;
+LL | | });
+ | |_____- supplied 1 argument
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0057`.