Add tests

tests/ui/ergonomic-clones/async/local-type.rs

@@ -0,0 +1,9 @@
+// Check that using the parameter name in its type does not ICE.
+//@ edition:2018
+
+#![feature(ergonomic_clones)]
+
+fn main() {
+    let _ = async use |x: x| x; //~ ERROR expected type
+    let _ = async use |x: bool| -> x { x }; //~ ERROR expected type
+}

tests/ui/ergonomic-clones/async/local-type.stderr

@@ -0,0 +1,15 @@
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type.rs:7:27
+   |
+LL |     let _ = async use |x: x| x;
+   |                           ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type.rs:8:36
+   |
+LL |     let _ = async use |x: bool| -> x { x };
+   |                                    ^ not a type
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0573`.

tests/ui/ergonomic-clones/closure/basic.rs

@@ -40,4 +40,18 @@ fn ergonomic_clone_closure_use_cloned() -> Foo {
     f
 }
 
+fn ergonomic_clone_closure_copy() -> i32 {
+    let i = 1;
+
+    let i1 = use || {
+        i
+    };
+
+    let i2 = use || {
+        i
+    };
+
+    i
+}
+
 fn main() {}

tests/ui/ergonomic-clones/closure/fn-once.rs

@@ -0,0 +1,13 @@
+#![feature(ergonomic_clones)]
+
+fn get_closure() -> Box<dyn Fn() -> Vec<u8>> {
+    let vec = vec![1u8, 2u8];
+
+    let closure = use || { //~ ERROR expected a closure
+        vec
+    };
+
+    Box::new(closure)
+}
+
+fn main() {}

tests/ui/ergonomic-clones/closure/fn-once.stderr

@@ -0,0 +1,16 @@
+error[E0525]: expected a closure that implements the `Fn` trait, but this closure only implements `FnOnce`
+  --> $DIR/fn-once.rs:6:19
+   |
+LL |     let closure = use || {
+   |                   ^^^^^^ this closure implements `FnOnce`, not `Fn`
+LL |         vec
+   |         --- closure is `FnOnce` because it moves the variable `vec` out of its environment
+...
+LL |     Box::new(closure)
+   |     ----------------- the requirement to implement `Fn` derives from here
+   |
+   = note: required for the cast from `Box<{closure@$DIR/fn-once.rs:6:19: 6:25}>` to `Box<(dyn Fn() -> Vec<u8> + 'static)>`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0525`.

tests/ui/ergonomic-clones/closure/local-type.rs

@@ -0,0 +1,8 @@
+// Check that using the parameter name in its type does not ICE.
+
+#![feature(ergonomic_clones)]
+
+fn main() {
+    let _ = use |x: x| x; //~ ERROR expected type
+    let _ = use |x: bool| -> x { x }; //~ ERROR expected type
+}

tests/ui/ergonomic-clones/closure/local-type.stderr

@@ -0,0 +1,15 @@
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type.rs:6:21
+   |
+LL |     let _ = use |x: x| x;
+   |                     ^ not a type
+
+error[E0573]: expected type, found local variable `x`
+  --> $DIR/local-type.rs:7:30
+   |
+LL |     let _ = use |x: bool| -> x { x };
+   |                              ^ not a type
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0573`.

tests/ui/ergonomic-clones/closure/once-move-out-on-heap.rs

@@ -0,0 +1,18 @@
+//@ run-pass
+// Testing guarantees provided by once functions.
+
+#![feature(ergonomic_clones)]
+
+use std::sync::Arc;
+
+fn foo<F: FnOnce()>(blk: F) {
+    blk();
+}
+
+pub fn main() {
+    let x = Arc::new(true);
+    foo(use || {
+        assert!(*x);
+        drop(x);
+    });
+}

tests/ui/ergonomic-clones/closure/parse.rs

@@ -0,0 +1,23 @@
+#![feature(ergonomic_clones)]
+
+fn parse1() {
+    || use {
+        //~^ ERROR expected one of `async`, `|`, or `||`, found `{`
+    };
+}
+
+fn parse2() {
+    move use || {
+        //~^ ERROR expected one of `async`, `|`, or `||`, found keyword `use`
+    };
+}
+
+fn parse3() {
+    use move || {
+        //~^ ERROR expected identifier, found keyword `move`
+        //~| ERROR expected one of `::`, `;`, or `as`, found `||`
+        // FIXME ideally we should error like in the previous example
+    };
+}
+
+fn main() {}

tests/ui/ergonomic-clones/closure/parse.stderr

@@ -0,0 +1,34 @@
+error: expected one of `async`, `|`, or `||`, found `{`
+  --> $DIR/parse.rs:4:12
+   |
+LL |     || use {
+   |     --     ^ expected one of `async`, `|`, or `||`
+   |     |
+   |     while parsing the body of this closure
+   |
+help: you might have meant to open the body of the closure, instead of enclosing the closure in a block
+   |
+LL ~ fn parse1() 
+LL ~     || { use {
+   |
+
+error: expected one of `async`, `|`, or `||`, found keyword `use`
+  --> $DIR/parse.rs:10:10
+   |
+LL |     move use || {
+   |          ^^^ expected one of `async`, `|`, or `||`
+
+error: expected identifier, found keyword `move`
+  --> $DIR/parse.rs:16:9
+   |
+LL |     use move || {
+   |         ^^^^ expected identifier, found keyword
+
+error: expected one of `::`, `;`, or `as`, found `||`
+  --> $DIR/parse.rs:16:14
+   |
+LL |     use move || {
+   |              ^^ expected one of `::`, `;`, or `as`
+
+error: aborting due to 4 previous errors
+

tests/ui/ergonomic-clones/closure/print-verbose.rs

@@ -0,0 +1,27 @@
+//@ compile-flags: -Zverbose-internals
+
+#![feature(ergonomic_clones)]
+
+fn to_fn_once<F: FnOnce()>(f: F) -> F {
+    f
+}
+
+fn f<T: std::fmt::Display>(y: T) {
+    struct Foo<U: std::fmt::Display> {
+        x: U,
+    };
+
+    let foo = Foo { x: "x" };
+
+    let c = to_fn_once(use || {
+        println!("{} {}", foo.x, y);
+    });
+
+    c();
+    c();
+    //~^ ERROR use of moved value
+}
+
+fn main() {
+    f("S");
+}

tests/ui/ergonomic-clones/closure/print-verbose.stderr

@@ -0,0 +1,20 @@
+error[E0382]: use of moved value: `c`
+  --> $DIR/print-verbose.rs:21:5
+   |
+LL |     let c = to_fn_once(use || {
+   |         - move occurs because `c` has type `{f<T>::{closure#0} closure_kind_ty=i32 closure_sig_as_fn_ptr_ty=extern "rust-call" fn(()) upvar_tys=(Foo<&'?9 str>, T)}`, which does not implement the `Copy` trait
+...
+LL |     c();
+   |     --- `c` moved due to this call
+LL |     c();
+   |     ^ value used here after move
+   |
+note: this value implements `FnOnce`, which causes it to be moved when called
+  --> $DIR/print-verbose.rs:20:5
+   |
+LL |     c();
+   |     ^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0382`.

tests/ui/ergonomic-clones/closure/print.rs

@@ -0,0 +1,25 @@
+#![feature(ergonomic_clones)]
+
+fn to_fn_once<F: FnOnce()>(f: F) -> F {
+    f
+}
+
+fn f<T: std::fmt::Display>(y: T) {
+    struct Foo<U: std::fmt::Display> {
+        x: U,
+    };
+
+    let foo = Foo { x: "x" };
+
+    let c = to_fn_once(use || {
+        println!("{} {}", foo.x, y);
+    });
+
+    c();
+    c();
+    //~^ ERROR use of moved value
+}
+
+fn main() {
+    f("S");
+}

tests/ui/ergonomic-clones/closure/print.stderr

@@ -0,0 +1,20 @@
+error[E0382]: use of moved value: `c`
+  --> $DIR/print.rs:19:5
+   |
+LL |     let c = to_fn_once(use || {
+   |         - move occurs because `c` has type `{closure@$DIR/print.rs:14:24: 14:30}`, which does not implement the `Copy` trait
+...
+LL |     c();
+   |     --- `c` moved due to this call
+LL |     c();
+   |     ^ value used here after move
+   |
+note: this value implements `FnOnce`, which causes it to be moved when called
+  --> $DIR/print.rs:18:5
+   |
+LL |     c();
+   |     ^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0382`.

tests/ui/ergonomic-clones/closure/with-binders.rs

@@ -0,0 +1,9 @@
+//@ edition:2021
+//@ check-pass
+
+#![feature(closure_lifetime_binder)]
+#![feature(ergonomic_clones)]
+
+fn main() {
+    for<'a> use || -> () {};
+}

tests/ui/ergonomic-clones/dotuse/parse.rs

@@ -0,0 +1,38 @@
+#![feature(ergonomic_clones)]
+
+fn parse1() {
+    1.use!;
+    //~^ ERROR: expected one of `.`, `;`, `?`, `}`, or an operator, found `!`
+    }
+
+fn parse2() {
+    1.use!(2);
+    //~^ ERROR: expected one of `.`, `;`, `?`, `}`, or an operator, found `!`
+    }
+
+fn parse3() {
+    1.use 2;
+    //~^ ERROR: expected one of `.`, `;`, `?`, `}`, or an operator, found `2`
+    }
+
+fn parse4() {
+    1.use? 2;
+    //~^ ERROR: expected one of `.`, `;`, `?`, `}`, or an operator, found `2`
+    }
+
+fn parse5() {
+    1.use();
+    //~^ ERROR: incorrect use of `use`
+}
+
+fn parse6() {
+    1.use(2);
+    //~^ ERROR: expected function, found `{integer}` [E0618]
+}
+
+fn parse7() {
+    1.use { 2 };
+    //~^ ERROR: expected one of `.`, `;`, `?`, `}`, or an operator, found `{`
+}
+
+fn main() {}

tests/ui/ergonomic-clones/dotuse/parse.stderr

@@ -0,0 +1,53 @@
+error: expected one of `.`, `;`, `?`, `}`, or an operator, found `!`
+  --> $DIR/parse.rs:4:10
+   |
+LL |     1.use!;
+   |          ^ expected one of `.`, `;`, `?`, `}`, or an operator
+
+error: expected one of `.`, `;`, `?`, `}`, or an operator, found `!`
+  --> $DIR/parse.rs:9:10
+   |
+LL |     1.use!(2);
+   |          ^ expected one of `.`, `;`, `?`, `}`, or an operator
+
+error: expected one of `.`, `;`, `?`, `}`, or an operator, found `2`
+  --> $DIR/parse.rs:14:11
+   |
+LL |     1.use 2;
+   |           ^ expected one of `.`, `;`, `?`, `}`, or an operator
+
+error: expected one of `.`, `;`, `?`, `}`, or an operator, found `2`
+  --> $DIR/parse.rs:19:12
+   |
+LL |     1.use? 2;
+   |            ^ expected one of `.`, `;`, `?`, `}`, or an operator
+
+error: incorrect use of `use`
+  --> $DIR/parse.rs:24:10
+   |
+LL |     1.use();
+   |          ^^
+   |
+help: `use` is not a method call, remove the parentheses
+   |
+LL -     1.use();
+LL +     1.use;
+   |
+
+error: expected one of `.`, `;`, `?`, `}`, or an operator, found `{`
+  --> $DIR/parse.rs:34:11
+   |
+LL |     1.use { 2 };
+   |           ^ expected one of `.`, `;`, `?`, `}`, or an operator
+
+error[E0618]: expected function, found `{integer}`
+  --> $DIR/parse.rs:29:5
+   |
+LL |     1.use(2);
+   |     ^^^^^---
+   |     |
+   |     call expression requires function
+
+error: aborting due to 7 previous errors
+
+For more information about this error, try `rustc --explain E0618`.