Better method call error messages

src/test/ui/argument-suggestions/basic.rs

@@ -0,0 +1,25 @@
+// Some basic "obvious" cases for the heuristic error messages added for #65853
+// One for each of the detected cases
+
+enum E { X, Y }
+enum F { X2, Y2 }
+struct G {}
+struct H {}
+struct X {}
+struct Y {}
+struct Z {}
+
+
+fn invalid(_i: u32) {}
+fn extra() {}
+fn missing(_i: u32) {}
+fn swapped(_i: u32, _s: &str) {}
+fn permuted(_x: X, _y: Y, _z: Z) {}
+
+fn main() {
+    invalid(1.0); //~ ERROR arguments to this function are incorrect
+    extra(""); //~ ERROR arguments to this function are incorrect
+    missing(); //~ ERROR arguments to this function are incorrect
+    swapped("", 1); //~ ERROR arguments to this function are incorrect
+    permuted(Y {}, Z {}, X {}); //~ ERROR arguments to this function are incorrect
+}

src/test/ui/argument-suggestions/basic.stderr

@@ -0,0 +1,79 @@
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/basic.rs:20:13
+   |
+LL |     invalid(1.0);
+   |             ^^^ expected u32, found {float}
+   |
+note: function defined here
+  --> $DIR/basic.rs:13:4
+   |
+LL | fn invalid(_i: u32) {}
+   |    ^^^^^^^ -------
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/basic.rs:21:11
+   |
+LL |     extra("");
+   |           ^^
+   |           |
+   |           no parameter of type &'static str is needed in extra
+   |           help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/basic.rs:14:4
+   |
+LL | fn extra() {}
+   |    ^^^^^
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/basic.rs:22:13
+   |
+LL |     missing();
+   |             ^ missing argument of type u32
+   |
+note: function defined here
+  --> $DIR/basic.rs:15:4
+   |
+LL | fn missing(_i: u32) {}
+   |    ^^^^^^^ -------
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/basic.rs:23:13
+   |
+LL |     swapped("", 1);
+   |             ^^  ^ expected &str, found {integer}
+   |             |
+   |             expected u32, found &'static str
+   |
+note: function defined here
+  --> $DIR/basic.rs:16:4
+   |
+LL | fn swapped(_i: u32, _s: &str) {}
+   |    ^^^^^^^ -------  --------
+help: swapping these two arguments might help
+   |
+LL |     swapped(1, "");
+   |             ^  ^^
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/basic.rs:24:14
+   |
+LL |     permuted(Y {}, Z {}, X {});
+   |              ^^^^  ^^^^  ^^^^ expected Z, found X
+   |              |     |
+   |              |     expected Y, found Z
+   |              expected X, found Y
+   |
+note: function defined here
+  --> $DIR/basic.rs:17:4
+   |
+LL | fn permuted(_x: X, _y: Y, _z: Z) {}
+   |    ^^^^^^^^ -----  -----  -----
+help: reordering these parameters might help
+   |
+LL |     permuted(X {}, Y {}, Z {});
+   |              ^^^^  ^^^^  ^^^^
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0059`.

src/test/ui/argument-suggestions/complex.rs

@@ -0,0 +1,16 @@
+// A complex case with mixed suggestions from #65853
+
+enum E { X, Y }
+enum F { X2, Y2 }
+struct G {}
+struct H {}
+struct X {}
+struct Y {}
+struct Z {}
+
+fn complex(_i: u32, _s: &str, _e: E, _f: F, _g: G, _x: X, _y: Y, _z: Z ) {}
+
+fn main() {
+  complex(1.0, H {}, &"", G{}, F::X2, Z {}, X {}, Y {});
+  //~^ ERROR arguments to this function are incorrect
+}

src/test/ui/argument-suggestions/complex.stderr

@@ -0,0 +1,27 @@
+error[E0059]: multiple arguments to this function are incorrect
+  --> $DIR/complex.rs:14:11
+   |
+LL |   complex(1.0, H {}, &"", G{}, F::X2, Z {}, X {}, Y {});
+   |           ^^^  ^^^^      ^^^^  ^^^^^  ^^^^  ^^^^  ^^^^ expected Z, found Y
+   |           |    |         ||    |      |     |
+   |           |    |         ||    |      |     expected Y, found X
+   |           |    |         ||    |      expected X, found Z
+   |           |    |         ||    expected G, found F
+   |           |    |         |expected F, found G
+   |           |    |         missing argument of type E
+   |           |    no parameter of type H is needed in complex
+   |           expected u32, found {float}
+   |
+note: function defined here
+  --> $DIR/complex.rs:11:4
+   |
+LL | fn complex(_i: u32, _s: &str, _e: E, _f: F, _g: G, _x: X, _y: Y, _z: Z ) {}
+   |    ^^^^^^^ -------  --------  -----  -----  -----  -----  -----  ------
+help: the following changes might help
+   |
+LL |   complex( {u32},, &"", {E}, F::X2, G{}, X {}, Y {}, Z {});
+   |            ^^^^^^ --    ^^^^ ^^^^^  ^^^  ^^^^  ^^^^  ^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0059`.

src/test/ui/argument-suggestions/extra_arguments.rs

@@ -0,0 +1,20 @@
+fn empty() {}
+fn one_arg(_a: i32) {}
+fn two_arg_same(_a: i32, _b: i32) {}
+fn two_arg_diff(_a: i32, _b: &str) {}
+
+fn main() {
+  empty(""); //~ ERROR arguments to this function are incorrect
+
+  one_arg(1, 1); //~ ERROR arguments to this function are incorrect
+  one_arg(1, ""); //~ ERROR arguments to this function are incorrect
+  one_arg(1, "", 1.0); //~ ERROR arguments to this function are incorrect
+
+  two_arg_same(1, 1, 1); //~ ERROR arguments to this function are incorrect
+  two_arg_same(1, 1, 1.0); //~ ERROR arguments to this function are incorrect
+
+  two_arg_diff(1, 1, ""); //~ ERROR arguments to this function are incorrect
+  two_arg_diff(1, "", ""); //~ ERROR arguments to this function are incorrect
+  two_arg_diff(1, 1, "", ""); //~ ERROR arguments to this function are incorrect
+  two_arg_diff(1, "", 1, ""); //~ ERROR arguments to this function are incorrect
+}

src/test/ui/argument-suggestions/extra_arguments.stderr

@@ -0,0 +1,168 @@
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:7:9
+   |
+LL |   empty("");
+   |         ^^
+   |         |
+   |         no parameter of type &'static str is needed in empty
+   |         help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:1:4
+   |
+LL | fn empty() {}
+   |    ^^^^^
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:9:14
+   |
+LL |   one_arg(1, 1);
+   |              ^
+   |              |
+   |              no parameter of type {integer} is needed in one_arg
+   |              help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:2:4
+   |
+LL | fn one_arg(_a: i32) {}
+   |    ^^^^^^^ -------
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:10:14
+   |
+LL |   one_arg(1, "");
+   |              ^^
+   |              |
+   |              no parameter of type &'static str is needed in one_arg
+   |              help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:2:4
+   |
+LL | fn one_arg(_a: i32) {}
+   |    ^^^^^^^ -------
+
+error[E0059]: multiple arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:11:14
+   |
+LL |   one_arg(1, "", 1.0);
+   |              ^^  ^^^ no parameter of type {float} is needed in one_arg
+   |              |
+   |              no parameter of type &'static str is needed in one_arg
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:2:4
+   |
+LL | fn one_arg(_a: i32) {}
+   |    ^^^^^^^ -------
+help: removing these argument may help
+   |
+LL |   one_arg(1, );
+   |             --  --
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:13:22
+   |
+LL |   two_arg_same(1, 1, 1);
+   |                      ^
+   |                      |
+   |                      no parameter of type {integer} is needed in two_arg_same
+   |                      help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:3:4
+   |
+LL | fn two_arg_same(_a: i32, _b: i32) {}
+   |    ^^^^^^^^^^^^ -------  -------
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:14:22
+   |
+LL |   two_arg_same(1, 1, 1.0);
+   |                      ^^^
+   |                      |
+   |                      no parameter of type {float} is needed in two_arg_same
+   |                      help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:3:4
+   |
+LL | fn two_arg_same(_a: i32, _b: i32) {}
+   |    ^^^^^^^^^^^^ -------  -------
+
+error[E0059]: multiple arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:16:19
+   |
+LL |   two_arg_diff(1, 1, "");
+   |                   ^ ^^^ no parameter of type &'static str is needed in two_arg_diff
+   |                   | |
+   |                   | missing argument of type &str
+   |                   no parameter of type {integer} is needed in two_arg_diff
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:4:4
+   |
+LL | fn two_arg_diff(_a: i32, _b: &str) {}
+   |    ^^^^^^^^^^^^ -------  --------
+help: the following changes might help
+   |
+LL |   two_arg_diff(1,  {&str}, );
+   |                  --  ^^^^^^^--
+
+error[E0059]: arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:17:23
+   |
+LL |   two_arg_diff(1, "", "");
+   |                       ^^
+   |                       |
+   |                       no parameter of type &'static str is needed in two_arg_diff
+   |                       help: removing this argument may help
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:4:4
+   |
+LL | fn two_arg_diff(_a: i32, _b: &str) {}
+   |    ^^^^^^^^^^^^ -------  --------
+
+error[E0059]: multiple arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:18:19
+   |
+LL |   two_arg_diff(1, 1, "", "");
+   |                   ^ ^^^  ^^ no parameter of type &'static str is needed in two_arg_diff
+   |                   | ||
+   |                   | |no parameter of type &'static str is needed in two_arg_diff
+   |                   | missing argument of type &str
+   |                   no parameter of type {integer} is needed in two_arg_diff
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:4:4
+   |
+LL | fn two_arg_diff(_a: i32, _b: &str) {}
+   |    ^^^^^^^^^^^^ -------  --------
+help: the following changes might help
+   |
+LL |   two_arg_diff(1,  {&str}, );
+   |                  --  ^^^^^^^---
+
+error[E0059]: multiple arguments to this function are incorrect
+  --> $DIR/extra_arguments.rs:19:23
+   |
+LL |   two_arg_diff(1, "", 1, "");
+   |                       ^  ^^ no parameter of type &'static str is needed in two_arg_diff
+   |                       |
+   |                       no parameter of type {integer} is needed in two_arg_diff
+   |
+note: function defined here
+  --> $DIR/extra_arguments.rs:4:4
+   |
+LL | fn two_arg_diff(_a: i32, _b: &str) {}
+   |    ^^^^^^^^^^^^ -------  --------
+help: removing these argument may help
+   |
+LL |   two_arg_diff(1, "", );
+   |                      -- --
+
+error: aborting due to 10 previous errors
+
+For more information about this error, try `rustc --explain E0059`.

src/test/ui/argument-suggestions/invalid_arguments.rs

@@ -0,0 +1,43 @@
+// More nuanced test cases for invalid arguments #65853
+
+struct X {}
+
+fn one_arg(_a: i32) {}
+fn two_arg_same(_a: i32, _b: i32) {}
+fn two_arg_diff(_a: i32, _b: f32) {}
+fn three_arg_diff(_a: i32, _b: f32, _c: &str) {}
+fn three_arg_repeat(_a: i32, _b: i32, _c: &str) {}
+
+fn main() {
+  // Providing an incorrect argument for a single parameter function
+  one_arg(1.0); //~ ERROR arguments to this function are incorrect
+
+  // Providing one or two invalid arguments to a two parameter function
+  two_arg_same(1, ""); //~ ERROR arguments to this function are incorrect
+  two_arg_same("", 1); //~ ERROR arguments to this function are incorrect
+  two_arg_same("", ""); //~ ERROR arguments to this function are incorrect
+  two_arg_diff(1, ""); //~ ERROR arguments to this function are incorrect
+  two_arg_diff("", 1.0); //~ ERROR arguments to this function are incorrect
+  two_arg_diff("", ""); //~ ERROR arguments to this function are incorrect
+
+  // Providing invalid arguments to a three parameter function
+  three_arg_diff(X{}, 1.0, ""); //~ ERROR arguments to this function are incorrect
+  three_arg_diff(1, X {}, ""); //~ ERROR arguments to this function are incorrect
+  three_arg_diff(1, 1.0, X {}); //~ ERROR arguments to this function are incorrect
+
+  three_arg_diff(X {}, X {}, ""); //~ ERROR arguments to this function are incorrect
+  three_arg_diff(X {}, 1.0, X {}); //~ ERROR arguments to this function are incorrect
+  three_arg_diff(1, X {}, X {}); //~ ERROR arguments to this function are incorrect
+
+  three_arg_diff(X {}, X {}, X {}); //~ ERROR arguments to this function are incorrect
+
+  three_arg_repeat(X {}, 1, ""); //~ ERROR arguments to this function are incorrect
+  three_arg_repeat(1, X {}, ""); //~ ERROR arguments to this function are incorrect
+  three_arg_repeat(1, 1, X {}); //~ ERROR arguments to this function are incorrect
+
+  three_arg_repeat(X {}, X {}, ""); //~ ERROR arguments to this function are incorrect
+  three_arg_repeat(X {}, 1, X {}); //~ ERROR arguments to this function are incorrect
+  three_arg_repeat(1, X {}, X{}); //~ ERROR arguments to this function are incorrect
+
+  three_arg_repeat(X {}, X {}, X {}); //~ ERROR arguments to this function are incorrect
+}