Auto merge of #46633 - estebank:arg-mismatch, r=arielb1

Point at whole method call instead of args

To avoid confusion in cases where the code is

```rust
fn foo() {}
/ foo(
|     bar()
|     ^^^ current diagnostics point here for arg count mismatch
| );
|_^ new diagnostic span points here
```

as this leads to confusion making people think that the diagnostic is
talking about `bar`'s arg count, not `foo`'s.

Point at `fn`s definition on arg mismatch, just like we do for closures.

Re #42855, Fix #45633.

src/librustc/traits/error_reporting.rs

@@ -714,7 +714,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
  let found_did = found_trait_ty.ty_to_def_id();
  let found_span = found_did.and_then(|did| {
  self.tcx.hir.span_if_local(did)
- });
+ }).map(|sp| self.tcx.sess.codemap().def_span(sp)); // the sp could be an fn def
 
  let found_ty_count =
  match found_trait_ref.skip_binder().substs.type_at(1).sty {
@@ -751,7 +751,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
  //
  // ```
  // [1i32, 2, 3].sort_by(|(a, b)| ..)
- // //  ^^^^^^^^
+ // // ^^^^^^^ --------
  // // expected_trait_ref: std::ops::FnMut<(&i32, &i32)>
  // // found_trait_ref: std::ops::FnMut<(&i32,)>
  // ```

src/librustc/ty/sty.rs

@@ -1559,6 +1559,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
  TyAdt(def, _) => Some(def.did),
  TyForeign(did) => Some(did),
  TyClosure(id, _) => Some(id),
+ TyFnDef(id, _) => Some(id),
  _ => None,
  }
  }

src/librustc_typeck/check/mod.rs

@@ -2432,21 +2432,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
  let mut expected_arg_tys = expected_arg_tys;
  let expected_arg_count = fn_inputs.len();
 
- let sp_args = if args.len() > 0 {
- let (first, args) = args.split_at(1);
- let mut sp_tmp = first[0].span;
- for arg in args {
- let sp_opt = self.sess().codemap().merge_spans(sp_tmp, arg.span);
- if ! sp_opt.is_some() {
- break;
- }
- sp_tmp = sp_opt.unwrap();
- };
- sp_tmp
- } else {
- sp
- };
-
  fn parameter_count_error<'tcx>(sess: &Session,
  sp: Span,
  expr_sp: Span,
@@ -2465,7 +2450,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
  if arg_count == 1 {" was"} else {"s were"}),
  DiagnosticId::Error(error_code.to_owned()));
 
- if let Some(def_s) = def_span {
+ if let Some(def_s) = def_span.map(|sp| sess.codemap().def_span(sp)) {
  err.span_label(def_s, "defined here");
  }
  if sugg_unit {
@@ -2489,7 +2474,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
  let tuple_type = self.structurally_resolved_type(sp, fn_inputs[0]);
  match tuple_type.sty {
  ty::TyTuple(arg_types, _) if arg_types.len() != args.len() => {
- parameter_count_error(tcx.sess, sp_args, expr_sp, arg_types.len(), args.len(),
+ parameter_count_error(tcx.sess, sp, expr_sp, arg_types.len(), args.len(),
  "E0057", false, def_span, false);
  expected_arg_tys = &[];
  self.err_args(args.len())
@@ -2518,7 +2503,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
  if supplied_arg_count >= expected_arg_count {
  fn_inputs.to_vec()
  } else {
- parameter_count_error(tcx.sess, sp_args, expr_sp, expected_arg_count,
+ parameter_count_error(tcx.sess, sp, expr_sp, expected_arg_count,
  supplied_arg_count, "E0060", true, def_span, false);
  expected_arg_tys = &[];
  self.err_args(supplied_arg_count)
@@ -2532,7 +2517,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
  } else {
  false
  };
- parameter_count_error(tcx.sess, sp_args, expr_sp, expected_arg_count,
+ parameter_count_error(tcx.sess, sp, expr_sp, expected_arg_count,
  supplied_arg_count, "E0061", false, def_span, sugg_unit);
  expected_arg_tys = &[];
  self.err_args(supplied_arg_count)

src/test/ui/anonymous-higher-ranked-lifetime.stderr

@@ -2,7 +2,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:12:5
  |
 12 | f1(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'r, 's> fn(&'r (), &'s ()) -> _`
  |
@@ -12,7 +12,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:13:5
  |
 13 | f2(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'a, 'r> fn(&'a (), &'r ()) -> _`
  |
@@ -22,7 +22,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:14:5
  |
 14 | f3(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'r> fn(&(), &'r ()) -> _`
  |
@@ -32,7 +32,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:15:5
  |
 15 | f4(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'s, 'r> fn(&'s (), &'r ()) -> _`
  |
@@ -42,7 +42,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:16:5
  |
 16 | f5(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'r> fn(&'r (), &'r ()) -> _`
  |
@@ -52,7 +52,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:17:5
  |
 17 | g1(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'r> fn(&'r (), std::boxed::Box<for<'s> std::ops::Fn(&'s ()) + 'static>) -> _`
  |
@@ -62,7 +62,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:18:5
  |
 18 | g2(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'r> fn(&'r (), for<'s> fn(&'s ())) -> _`
  |
@@ -72,7 +72,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:19:5
  |
 19 | g3(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'s> fn(&'s (), std::boxed::Box<for<'r> std::ops::Fn(&'r ()) + 'static>) -> _`
  |
@@ -82,7 +82,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:20:5
  |
 20 | g4(|_: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ----------------- found signature of `fn((), ()) -> _`
+ | ^^ -------------- found signature of `fn((), ()) -> _`
  | |
  | expected signature of `for<'s> fn(&'s (), for<'r> fn(&'r ())) -> _`
  |
@@ -92,7 +92,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:21:5
  |
 21 | h1(|_: (), _: (), _: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ------------------------------- found signature of `fn((), (), (), ()) -> _`
+ | ^^ ---------------------------- found signature of `fn((), (), (), ()) -> _`
  | |
  | expected signature of `for<'r, 's> fn(&'r (), std::boxed::Box<for<'t0> std::ops::Fn(&'t0 ()) + 'static>, &'s (), for<'t0, 't1> fn(&'t0 (), &'t1 ())) -> _`
  |
@@ -102,7 +102,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/anonymous-higher-ranked-lifetime.rs:22:5
  |
 22 | h2(|_: (), _: (), _: (), _: ()| {}); //~ ERROR type mismatch
- | ^^ ------------------------------- found signature of `fn((), (), (), ()) -> _`
+ | ^^ ---------------------------- found signature of `fn((), (), (), ()) -> _`
  | |
  | expected signature of `for<'r, 't0> fn(&'r (), std::boxed::Box<for<'s> std::ops::Fn(&'s ()) + 'static>, &'t0 (), for<'s, 't1> fn(&'s (), &'t1 ())) -> _`
  |

src/test/ui/method-call-err-msg.stderr

@@ -1,29 +1,29 @@
 error[E0061]: this function takes 0 parameters but 1 parameter was supplied
- --> $DIR/method-call-err-msg.rs:25:12
+ --> $DIR/method-call-err-msg.rs:25:7
  |
 15 | fn zero(self) -> Foo { self }
- | ----------------------------- defined here
+ | -------------------- defined here
 ...
 25 | x.zero(0) //~ ERROR this function takes 0 parameters but 1 parameter was supplied
- |  ^ expected 0 parameters
+ | ^^^^ expected 0 parameters
 
 error[E0061]: this function takes 1 parameter but 0 parameters were supplied
  --> $DIR/method-call-err-msg.rs:27:7
  |
 17 | fn one(self, _: isize) -> Foo { self }
- | -------------------------------------- defined here
+ | ----------------------------- defined here
 ...
 27 | .one() //~ ERROR this function takes 1 parameter but 0 parameters were supplied
  | ^^^ expected 1 parameter
 
 error[E0061]: this function takes 2 parameters but 1 parameter was supplied
- --> $DIR/method-call-err-msg.rs:29:11
+ --> $DIR/method-call-err-msg.rs:29:7
  |
 19 | fn two(self, _: isize, _: isize) -> Foo { self }
- | ------------------------------------------------ defined here
+ | --------------------------------------- defined here
 ...
 29 | .two(0); //~ ERROR this function takes 2 parameters but 1 parameter was supplied
- |  ^ expected 2 parameters
+ | ^^^ expected 2 parameters
 
 error[E0599]: no method named `take` found for type `Foo` in the current scope
  --> $DIR/method-call-err-msg.rs:34:7

src/test/ui/mismatched_types/E0631.stderr

@@ -2,7 +2,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/E0631.rs:17:5
  |
 17 | foo(|_: isize| {}); //~ ERROR type mismatch
- | ^^^ ------------- found signature of `fn(isize) -> _`
+ | ^^^ ---------- found signature of `fn(isize) -> _`
  | |
  | expected signature of `fn(usize) -> _`
  |
@@ -12,7 +12,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/E0631.rs:18:5
  |
 18 | bar(|_: isize| {}); //~ ERROR type mismatch
- | ^^^ ------------- found signature of `fn(isize) -> _`
+ | ^^^ ---------- found signature of `fn(isize) -> _`
  | |
  | expected signature of `fn(usize) -> _`
  |
@@ -21,22 +21,22 @@ error[E0631]: type mismatch in closure arguments
 error[E0631]: type mismatch in function arguments
  --> $DIR/E0631.rs:19:5
  |
+16 | fn f(_: u64) {}
+ | ------------ found signature of `fn(u64) -> _`
+...
 19 | foo(f); //~ ERROR type mismatch
- | ^^^
- | |
- | expected signature of `fn(usize) -> _`
- | found signature of `fn(u64) -> _`
+ | ^^^ expected signature of `fn(usize) -> _`
  |
  = note: required by `foo`
 
 error[E0631]: type mismatch in function arguments
  --> $DIR/E0631.rs:20:5
  |
+16 | fn f(_: u64) {}
+ | ------------ found signature of `fn(u64) -> _`
+...
 20 | bar(f); //~ ERROR type mismatch
- | ^^^
- | |
- | expected signature of `fn(usize) -> _`
- | found signature of `fn(u64) -> _`
+ | ^^^ expected signature of `fn(usize) -> _`
  |
  = note: required by `bar`
 

src/test/ui/mismatched_types/closure-arg-count.rs

@@ -27,4 +27,11 @@ fn main() {
  //~^ ERROR closure is expected to take
  let _it = vec![1, 2, 3].into_iter().enumerate().map(|i, x, y| i);
  //~^ ERROR closure is expected to take
+ let _it = vec![1, 2, 3].into_iter().enumerate().map(foo);
+ //~^ ERROR function is expected to take
+ let bar = |i, x, y| i;
+ let _it = vec![1, 2, 3].into_iter().enumerate().map(bar);
+ //~^ ERROR closure is expected to take
 }
+
+fn foo() {}

src/test/ui/mismatched_types/closure-arg-count.stderr

@@ -56,5 +56,22 @@ error[E0593]: closure is expected to take a single 2-tuple as argument, but it t
  | |
  | expected closure that takes a single 2-tuple as argument
 
-error: aborting due to 7 previous errors
+error[E0593]: function is expected to take a single 2-tuple as argument, but it takes 0 arguments
+ --> $DIR/closure-arg-count.rs:30:53
+ |
+30 | let _it = vec![1, 2, 3].into_iter().enumerate().map(foo);
+ | ^^^ expected function that takes a single 2-tuple as argument
+...
+37 | fn foo() {}
+ | -------- takes 0 arguments
+
+error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 3 distinct arguments
+ --> $DIR/closure-arg-count.rs:33:53
+ |
+32 | let bar = |i, x, y| i;
+ | --------- takes 3 distinct arguments
+33 | let _it = vec![1, 2, 3].into_iter().enumerate().map(bar);
+ | ^^^ expected closure that takes a single 2-tuple as argument
+
+error: aborting due to 9 previous errors
 

src/test/ui/mismatched_types/fn-variance-1.rs

@@ -9,8 +9,10 @@
 // except according to those terms.
 
 fn takes_imm(x: &isize) { }
+//~^ NOTE found signature
 
 fn takes_mut(x: &mut isize) { }
+//~^ NOTE found signature
 
 fn apply<T, F>(t: T, f: F) where F: FnOnce(T) {
  f(t)
@@ -22,12 +24,10 @@ fn main() {
  //~^ ERROR type mismatch
  //~| NOTE required by `apply`
  //~| NOTE expected signature
- //~| NOTE found signature
 
  apply(&mut 3, takes_mut);
  apply(&mut 3, takes_imm);
  //~^ ERROR type mismatch
  //~| NOTE required by `apply`
  //~| NOTE expected signature
- //~| NOTE found signature
 }

src/test/ui/mismatched_types/fn-variance-1.stderr

@@ -1,22 +1,22 @@
 error[E0631]: type mismatch in function arguments
- --> $DIR/fn-variance-1.rs:21:5
+ --> $DIR/fn-variance-1.rs:23:5
  |
-21 |  apply(&3, takes_mut);
- |  ^^^^^
- | |
- | expected signature of `fn(&{integer}) -> _`
- | found signature of `for<'r> fn(&'r mut isize) -> _`
+14 | fn takes_mut(x: &mut isize) { }
+ | --------------------------- found signature of `for<'r> fn(&'r mut isize) -> _`
+...
+23 | apply(&3, takes_mut);
+ | ^^^^^ expected signature of `fn(&{integer}) -> _`
  |
  = note: required by `apply`
 
 error[E0631]: type mismatch in function arguments
- --> $DIR/fn-variance-1.rs:28:5
+ --> $DIR/fn-variance-1.rs:29:5
  |
-28 |  apply(&mut 3, takes_imm);
- |  ^^^^^
- | |
- | expected signature of `fn(&mut {integer}) -> _`
- | found signature of `for<'r> fn(&'r isize) -> _`
+11 | fn takes_imm(x: &isize) { }
+ | ----------------------- found signature of `for<'r> fn(&'r isize) -> _`
+...
+29 | apply(&mut 3, takes_imm);
+ | ^^^^^ expected signature of `fn(&mut {integer}) -> _`
  |
  = note: required by `apply`
 

src/test/ui/mismatched_types/overloaded-calls-bad.stderr

@@ -14,10 +14,10 @@ error[E0057]: this function takes 1 parameter but 0 parameters were supplied
  | ^^^ expected 1 parameter
 
 error[E0057]: this function takes 1 parameter but 2 parameters were supplied
- --> $DIR/overloaded-calls-bad.rs:44:17
+ --> $DIR/overloaded-calls-bad.rs:44:15
  |
 44 | let ans = s("burma", "shave");
- |  ^^^^^^^^^^^^^^^^ expected 1 parameter
+ | ^^^^^^^^^^^^^^^^^^^ expected 1 parameter
 
 error: aborting due to 3 previous errors
 

src/test/ui/mismatched_types/unboxed-closures-vtable-mismatch.stderr

@@ -2,7 +2,7 @@ error[E0631]: type mismatch in closure arguments
  --> $DIR/unboxed-closures-vtable-mismatch.rs:24:13
  |
 22 | let f = to_fn_mut(|x: usize, y: isize| -> isize { (x as isize) + y });
- | -------------------------------------------------- found signature of `fn(usize, isize) -> _`
+ | ----------------------------- found signature of `fn(usize, isize) -> _`
 23 | //~^ NOTE found signature of `fn(usize, isize)
 24 | let z = call_it(3, f);
  | ^^^^^^^ expected signature of `fn(isize, isize) -> _`

src/test/ui/span/E0057.stderr

@@ -5,10 +5,10 @@ error[E0057]: this function takes 1 parameter but 0 parameters were supplied
  | ^^^ expected 1 parameter
 
 error[E0057]: this function takes 1 parameter but 2 parameters were supplied
- --> $DIR/E0057.rs:15:15
+ --> $DIR/E0057.rs:15:13
  |
 15 | let c = f(2, 3); //~ ERROR E0057
- |  ^^^^ expected 1 parameter
+ | ^^^^^^^ expected 1 parameter
 
 error: aborting due to 2 previous errors