Rollup merge of #98607 - compiler-errors:tuple-wrap-suggestion, r=oli-obk

Clean up arg mismatch diagnostic, generalize tuple wrap suggestion

This is based on top of #97542, so just look at the last commit which contains the relevant changes.

1. Remove `final_arg_types` which was one of the last places we were using raw (`usize`) indices instead of typed indices in the arg mismatch suggestion code.
2. Improve the tuple wrap suggestion, now we suggest things like `call(a, b, c, d)` -> `call(a, (b, c), d)` 😺
3. Folded in fix #98645

Author: Dylan-DPC

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -342,8 +342,8 @@ pub fn same_type_modulo_infer<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
         )
         | (&ty::Infer(ty::InferTy::TyVar(_)), _)
         | (_, &ty::Infer(ty::InferTy::TyVar(_))) => true,
-        (&ty::Ref(reg_a, ty_a, mut_a), &ty::Ref(reg_b, ty_b, mut_b)) => {
-            reg_a == reg_b && mut_a == mut_b && same_type_modulo_infer(*ty_a, *ty_b)
+        (&ty::Ref(_, ty_a, mut_a), &ty::Ref(_, ty_b, mut_b)) => {
+            mut_a == mut_b && same_type_modulo_infer(*ty_a, *ty_b)
         }
         _ => a == b,
     }

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

@@ -5,10 +5,7 @@ LL | / pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
 LL | |
 LL | |     loop {}
 LL | | }
-   | | ^
-   | | |
-   | |_call the function in a closure: `|| unsafe { /* code */ }`
-   |   required by a bound introduced by this call
+   | |_^ call the function in a closure: `|| unsafe { /* code */ }`
    |
    = help: the trait `Fn<(proc_macro::TokenStream,)>` is not implemented for `unsafe extern "C" fn(i32, u32) -> u32 {foo}`
    = note: unsafe function cannot be called generically without an unsafe block

src/test/ui/proc-macro/signature.stderr

@@ -9,7 +9,7 @@ note: tuple variant defined here
    |
 LL |     Ok(#[stable(feature = "rust1", since = "1.0.0")] T),
    |     ^^
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |     let _: Result<(i32, i8), ()> = Ok((1, 2));
    |                                       +    +
@@ -25,7 +25,7 @@ note: tuple variant defined here
    |
 LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
    |     ^^^^
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |     let _: Option<(i32, i8, &'static str)> = Some((1, 2, "hi"));
    |                                                   +          +
@@ -97,7 +97,7 @@ note: function defined here
    |
 LL | fn two_ints(_: (i32, i32)) {
    |    ^^^^^^^^ -------------
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |     two_ints((1, 2));
    |              +    +
@@ -113,7 +113,7 @@ note: function defined here
    |
 LL | fn with_generic<T: Copy + Send>((a, b): (i32, T)) {
    |    ^^^^^^^^^^^^                 ----------------
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |     with_generic((3, 4));
    |                  +    +
@@ -129,7 +129,7 @@ note: function defined here
    |
 LL | fn with_generic<T: Copy + Send>((a, b): (i32, T)) {
    |    ^^^^^^^^^^^^                 ----------------
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |         with_generic((a, b));
    |                      +    +

src/test/ui/suggestions/args-instead-of-tuple.stderr

@@ -0,0 +1,10 @@
+fn foo(s: &str, a: (i32, i32), s2: &str) {}
+
+fn bar(s: &str, a: (&str,), s2: &str) {}
+
+fn main() {
+    foo("hi", 1, 2, "hi");
+    //~^ ERROR this function takes 3 arguments but 4 arguments were supplied
+    bar("hi", "hi", "hi");
+    //~^ ERROR mismatched types
+}

src/test/ui/tuple/add-tuple-within-arguments.rs

@@ -0,0 +1,40 @@
+error[E0061]: this function takes 3 arguments but 4 arguments were supplied
+  --> $DIR/add-tuple-within-arguments.rs:6:5
+   |
+LL |     foo("hi", 1, 2, "hi");
+   |     ^^^
+   |
+note: function defined here
+  --> $DIR/add-tuple-within-arguments.rs:1:4
+   |
+LL | fn foo(s: &str, a: (i32, i32), s2: &str) {}
+   |    ^^^ -------  -------------  --------
+help: wrap these arguments in parentheses to construct a tuple
+   |
+LL |     foo("hi", (1, 2), "hi");
+   |               +    +
+
+error[E0308]: mismatched types
+  --> $DIR/add-tuple-within-arguments.rs:8:15
+   |
+LL |     bar("hi", "hi", "hi");
+   |     ---       ^^^^ expected tuple, found `&str`
+   |     |
+   |     arguments to this function are incorrect
+   |
+   = note:  expected tuple `(&str,)`
+           found reference `&'static str`
+note: function defined here
+  --> $DIR/add-tuple-within-arguments.rs:3:4
+   |
+LL | fn bar(s: &str, a: (&str,), s2: &str) {}
+   |    ^^^ -------  ----------  --------
+help: use a trailing comma to create a tuple with one element
+   |
+LL |     bar("hi", ("hi",), "hi");
+   |               +    ++
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0061, E0308.
+For more information about an error, try `rustc --explain E0061`.

src/test/ui/tuple/add-tuple-within-arguments.stderr

@@ -9,7 +9,7 @@ note: function defined here
    |
 LL | fn test(t: (i32, i32)) {}
    |    ^^^^ -------------
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |     test((x.qux(), x.qux()));
    |          +                +

src/test/ui/tuple/wrong_argument_ice-2.stderr

@@ -9,7 +9,7 @@ note: associated function defined here
    |
 LL |     pub fn push_back(&mut self, value: T) {
    |            ^^^^^^^^^
-help: use parentheses to construct a tuple
+help: wrap these arguments in parentheses to construct a tuple
    |
 LL |         self.acc.push_back((self.current_provides, self.current_requires));
    |                            +                                            +

src/test/ui/tuple/wrong_argument_ice.stderr

@@ -2,7 +2,9 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:11:11
    |
 LL |     foo11("bar", &"baz");
-   |           ^^^^^ doesn't have a size known at compile-time
+   |     ----- ^^^^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<Path>`
@@ -15,7 +17,9 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:13:19
    |
 LL |     foo12(&"bar", "baz");
-   |                   ^^^^^ doesn't have a size known at compile-time
+   |     -----         ^^^^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<Path>`
@@ -28,7 +32,9 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:16:11
    |
 LL |     foo21("bar", &"baz");
-   |           ^^^^^ doesn't have a size known at compile-time
+   |     ----- ^^^^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<str>`
@@ -41,7 +47,9 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:18:19
    |
 LL |     foo22(&"bar", "baz");
-   |                   ^^^^^ doesn't have a size known at compile-time
+   |     -----         ^^^^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<str>`

src/test/ui/unsized/unsized-fn-param.stderr

@@ -44,6 +44,7 @@ fn f9<X: ?Sized>(x1: Box<S<X>>) {
 fn f10<X: ?Sized>(x1: Box<S<X>>) {
     f5(&(32, *x1));
     //~^ ERROR the size for values of type
+    //~| ERROR the size for values of type
 }
 
 pub fn main() {}

src/test/ui/unsized/unsized3.rs

@@ -100,6 +100,29 @@ LL - fn f9<X: ?Sized>(x1: Box<S<X>>) {
 LL + fn f9<X>(x1: Box<S<X>>) {
    |
 
+error[E0277]: the size for values of type `X` cannot be known at compilation time
+  --> $DIR/unsized3.rs:45:9
+   |
+LL | fn f10<X: ?Sized>(x1: Box<S<X>>) {
+   |        - this type parameter needs to be `std::marker::Sized`
+LL |     f5(&(32, *x1));
+   |     --  ^^^^^^^^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `S<X>`
+  --> $DIR/unsized3.rs:28:8
+   |
+LL | struct S<X: ?Sized> {
+   |        ^
+   = note: required because it appears within the type `({integer}, S<X>)`
+   = note: tuples must have a statically known size to be initialized
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+LL - fn f10<X: ?Sized>(x1: Box<S<X>>) {
+LL + fn f10<X>(x1: Box<S<X>>) {
+   |
+
 error[E0277]: the size for values of type `X` cannot be known at compilation time
   --> $DIR/unsized3.rs:45:8
    |
@@ -116,13 +139,21 @@ note: required because it appears within the type `S<X>`
 LL | struct S<X: ?Sized> {
    |        ^
    = note: required because it appears within the type `({integer}, S<X>)`
-   = note: tuples must have a statically known size to be initialized
+note: required by a bound in `f5`
+  --> $DIR/unsized3.rs:24:7
+   |
+LL | fn f5<Y>(x: &Y) {}
+   |       ^ required by this bound in `f5`
 help: consider removing the `?Sized` bound to make the type parameter `Sized`
    |
 LL - fn f10<X: ?Sized>(x1: Box<S<X>>) {
 LL + fn f10<X>(x1: Box<S<X>>) {
    |
+help: consider relaxing the implicit `Sized` restriction
+   |
+LL | fn f5<Y: ?Sized>(x: &Y) {}
+   |        ++++++++
 
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0277`.