Rollup merge of #80635 - sexxi-goose:use-place-instead-of-symbol, r=nikomatsakis`

Improve diagnostics when closure doesn't meet trait bound

Improves the diagnostics when closure doesn't meet trait bound by modifying `TypeckResuts::closure_kind_origins` such that `hir::Place` is used instead of `Symbol`. Using `hir::Place` to describe which capture influenced the decision of selecting a trait a closure satisfies to (Fn/FnMut/FnOnce, Copy) allows us to show precise path in the diagnostics when `capture_disjoint_field` feature is enabled.

Closes rust-lang/project-rfc-2229/issues/21

r? ```@nikomatsakis```

10 files changed, 251 insertions, 0 deletions

diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-multi-variant-diagnostics.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-multi-variant-diagnostics.rs
new file mode 100644
index 00000000000..2916d8c794f
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-multi-variant-diagnostics.rs
@@ -0,0 +1,31 @@
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+//~| `#[warn(incomplete_features)]` on by default
+//~| see issue #53488 <https://github.com/rust-lang/rust/issues/53488>
+
+// Check that precise paths are being reported back in the error message.
+
+
+enum MultiVariant {
+    Point(i32, i32),
+    Meta(i32)
+}
+
+fn main() {
+    let mut point = MultiVariant::Point(10, -10,);
+
+    let mut meta = MultiVariant::Meta(1);
+
+    let c = || {
+        if let MultiVariant::Point(ref mut x, _) = point {
+            *x += 1;
+        }
+
+        if let MultiVariant::Meta(ref mut v) = meta {
+            *v += 1;
+        }
+    };
+
+    let a = c;
+    let b = c; //~ ERROR use of moved value: `c` [E0382]
+}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-multi-variant-diagnostics.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-multi-variant-diagnostics.stderr
new file mode 100644
index 00000000000..de0bfe3bd76
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-multi-variant-diagnostics.stderr
@@ -0,0 +1,26 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/closure-origin-multi-variant-diagnostics.rs:1:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+error[E0382]: use of moved value: `c`
+  --> $DIR/closure-origin-multi-variant-diagnostics.rs:30:13
+   |
+LL |     let a = c;
+   |             - value moved here
+LL |     let b = c;
+   |             ^ value used here after move
+   |
+note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `point.0` out of its environment
+  --> $DIR/closure-origin-multi-variant-diagnostics.rs:20:52
+   |
+LL |         if let MultiVariant::Point(ref mut x, _) = point {
+   |                                                    ^^^^^
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0382`.
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-single-variant-diagnostics.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-single-variant-diagnostics.rs
new file mode 100644
index 00000000000..8486f03f2eb
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-single-variant-diagnostics.rs
@@ -0,0 +1,26 @@
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+//~| `#[warn(incomplete_features)]` on by default
+//~| see issue #53488 <https://github.com/rust-lang/rust/issues/53488>
+
+// Check that precise paths are being reported back in the error message.
+
+enum SingleVariant {
+    Point(i32, i32),
+}
+
+fn main() {
+    let mut point = SingleVariant::Point(10, -10);
+
+    let c = || {
+        // FIXME(project-rfc-2229#24): Change this to be a destructure pattern
+        // once this is fixed, to remove the warning.
+        if let SingleVariant::Point(ref mut x, _) = point {
+            //~^ WARNING: irrefutable if-let pattern
+            *x += 1;
+        }
+    };
+
+    let b = c;
+    let a = c; //~ ERROR use of moved value: `c` [E0382]
+}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-single-variant-diagnostics.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-single-variant-diagnostics.stderr
new file mode 100644
index 00000000000..ad66f6d7ffc
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-single-variant-diagnostics.stderr
@@ -0,0 +1,37 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/closure-origin-single-variant-diagnostics.rs:1:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+warning: irrefutable if-let pattern
+  --> $DIR/closure-origin-single-variant-diagnostics.rs:18:9
+   |
+LL | /         if let SingleVariant::Point(ref mut x, _) = point {
+LL | |
+LL | |             *x += 1;
+LL | |         }
+   | |_________^
+   |
+   = note: `#[warn(irrefutable_let_patterns)]` on by default
+
+error[E0382]: use of moved value: `c`
+  --> $DIR/closure-origin-single-variant-diagnostics.rs:25:13
+   |
+LL |     let b = c;
+   |             - value moved here
+LL |     let a = c;
+   |             ^ value used here after move
+   |
+note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `point.0` out of its environment
+  --> $DIR/closure-origin-single-variant-diagnostics.rs:18:53
+   |
+LL |         if let SingleVariant::Point(ref mut x, _) = point {
+   |                                                     ^^^^^
+
+error: aborting due to previous error; 2 warnings emitted
+
+For more information about this error, try `rustc --explain E0382`.
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-struct-diagnostics.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-struct-diagnostics.rs
new file mode 100644
index 00000000000..103890f1f35
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-struct-diagnostics.rs
@@ -0,0 +1,25 @@
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+//~| `#[warn(incomplete_features)]` on by default
+//~| see issue #53488 <https://github.com/rust-lang/rust/issues/53488>
+
+// Check that precise paths are being reported back in the error message.
+
+struct Y {
+    y: X
+}
+
+struct X {
+    a: u32,
+    b: u32,
+}
+
+fn main() {
+    let mut x = Y { y: X { a: 5, b: 0 } };
+    let hello = || {
+        x.y.a += 1;
+    };
+
+    let b = hello;
+    let c = hello; //~ ERROR use of moved value: `hello` [E0382]
+}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-struct-diagnostics.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-struct-diagnostics.stderr
new file mode 100644
index 00000000000..474d77b7cd2
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-struct-diagnostics.stderr
@@ -0,0 +1,26 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/closure-origin-struct-diagnostics.rs:1:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+error[E0382]: use of moved value: `hello`
+  --> $DIR/closure-origin-struct-diagnostics.rs:24:13
+   |
+LL |     let b = hello;
+   |             ----- value moved here
+LL |     let c = hello;
+   |             ^^^^^ value used here after move
+   |
+note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `x.y.a` out of its environment
+  --> $DIR/closure-origin-struct-diagnostics.rs:20:9
+   |
+LL |         x.y.a += 1;
+   |         ^^^^^
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0382`.
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics-1.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics-1.rs
new file mode 100644
index 00000000000..6b078d2329c
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics-1.rs
@@ -0,0 +1,16 @@
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+//~| `#[warn(incomplete_features)]` on by default
+//~| see issue #53488 <https://github.com/rust-lang/rust/issues/53488>
+
+// Check that precise paths are being reported back in the error message.
+
+fn main() {
+    let mut x = (5, 0);
+    let hello = || {
+        x.0 += 1;
+    };
+
+    let b = hello;
+    let c = hello; //~ ERROR use of moved value: `hello` [E0382]
+}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics-1.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics-1.stderr
new file mode 100644
index 00000000000..716728e96ec
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics-1.stderr
@@ -0,0 +1,26 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/closure-origin-tuple-diagnostics-1.rs:1:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+error[E0382]: use of moved value: `hello`
+  --> $DIR/closure-origin-tuple-diagnostics-1.rs:15:13
+   |
+LL |     let b = hello;
+   |             ----- value moved here
+LL |     let c = hello;
+   |             ^^^^^ value used here after move
+   |
+note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `x.0` out of its environment
+  --> $DIR/closure-origin-tuple-diagnostics-1.rs:11:9
+   |
+LL |         x.0 += 1;
+   |         ^^^
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0382`.
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.rs
new file mode 100644
index 00000000000..0638db60769
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.rs
@@ -0,0 +1,15 @@
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+//~| `#[warn(incomplete_features)]` on by default
+//~| see issue #53488 <https://github.com/rust-lang/rust/issues/53488>
+struct S(String, String);
+
+fn expect_fn<F: Fn()>(_f: F) {}
+
+fn main() {
+    let s = S(format!("s"), format!("s"));
+    let c = || { //~ ERROR expected a closure that implements the `Fn`
+        let s = s.1;
+    };
+    expect_fn(c);
+}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr
new file mode 100644
index 00000000000..77eb2a94ffb
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr
@@ -0,0 +1,23 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/closure-origin-tuple-diagnostics.rs:1:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+error[E0525]: expected a closure that implements the `Fn` trait, but this closure only implements `FnOnce`
+  --> $DIR/closure-origin-tuple-diagnostics.rs:11:13
+   |
+LL |     let c = || {
+   |             ^^ this closure implements `FnOnce`, not `Fn`
+LL |         let s = s.1;
+   |                 --- closure is `FnOnce` because it moves the variable `s.1` out of its environment
+LL |     };
+LL |     expect_fn(c);
+   |     --------- the requirement to implement `Fn` derives from here
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0525`.