Auto merge of #82951 - sexxi-goose:wr-mir-replace-methods2, r=nikomatsakis

Replace closures_captures and upvar_capture with closure_min_captures

Removed all uses of closures_captures and upvar_capture and refactored code to work with closure_min_captures. This also involved removing functions that were no longer needed like the bridge.

Closes https://github.com/rust-lang/project-rfc-2229/issues/18
r? `@nikomatsakis`

4 files changed, 259 insertions, 0 deletions

diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness.rs
new file mode 100644
index 00000000000..09491f296f6
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness.rs
@@ -0,0 +1,91 @@
+// check-pass
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+#![allow(unreachable_code)]
+#![warn(unused)]
+
+#[derive(Debug)]
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+pub fn f() {
+    let mut a = 1;
+    let mut c = Point{ x:1, y:0 };
+
+    // Captured by value, but variable is dead on entry.
+    (move || {
+        // This will not trigger a warning for unused variable as
+        // c.x will be treated as a Non-tracked place
+        c.x = 1;
+        println!("{}", c.x);
+        a = 1; //~ WARN value captured by `a` is never read
+        println!("{}", a);
+    })();
+
+    // Read and written to, but never actually used.
+    (move || {
+        // This will not trigger a warning for unused variable as
+        // c.x will be treated as a Non-tracked place
+        c.x += 1;
+        a += 1; //~ WARN unused variable: `a`
+    })();
+
+    (move || {
+        println!("{}", c.x);
+        // Value is read by closure itself on later invocations.
+        // This will not trigger a warning for unused variable as
+        // c.x will be treated as a Non-tracked place
+        c.x += 1;
+        println!("{}", a);
+        a += 1;
+    })();
+    let b = Box::new(42);
+    (move || {
+        println!("{}", c.x);
+        // Never read because this is FnOnce closure.
+        // This will not trigger a warning for unused variable as
+        // c.x will be treated as a Non-tracked place
+        c.x += 1;
+        println!("{}", a);
+        a += 1; //~ WARN value assigned to `a` is never read
+        drop(b);
+    })();
+}
+
+#[derive(Debug)]
+struct MyStruct<'a>  {
+    x: Option<& 'a str>,
+    y: i32,
+}
+
+pub fn nested() {
+    let mut a : Option<& str>;
+    a = None;
+    let mut b : Option<& str>;
+    b = None;
+    let mut d = MyStruct{ x: None, y: 1};
+    let mut e = MyStruct{ x: None, y: 1};
+    (|| {
+        (|| {
+            // This will not trigger a warning for unused variable as
+            // d.x will be treated as a Non-tracked place
+            d.x = Some("d1");
+            d.x = Some("d2");
+            a = Some("d1"); //~ WARN value assigned to `a` is never read
+            a = Some("d2");
+        })();
+        (move || {
+            // This will not trigger a warning for unused variable as
+            //e.x will be treated as a Non-tracked place
+            e.x = Some("e1");
+            e.x = Some("e2");
+            b = Some("e1"); //~ WARN value assigned to `b` is never read
+                            //~| WARN unused variable: `b`
+            b = Some("e2"); //~ WARN value assigned to `b` is never read
+        })();
+    })();
+}
+
+fn main() {}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness.stderr
new file mode 100644
index 00000000000..81bbc4e1dc0
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness.stderr
@@ -0,0 +1,79 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/liveness.rs:2:12
+   |
+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: value captured by `a` is never read
+  --> $DIR/liveness.rs:23:9
+   |
+LL |         a = 1;
+   |         ^
+   |
+note: the lint level is defined here
+  --> $DIR/liveness.rs:5:9
+   |
+LL | #![warn(unused)]
+   |         ^^^^^^
+   = note: `#[warn(unused_assignments)]` implied by `#[warn(unused)]`
+   = help: did you mean to capture by reference instead?
+
+warning: unused variable: `a`
+  --> $DIR/liveness.rs:32:9
+   |
+LL |         a += 1;
+   |         ^
+   |
+note: the lint level is defined here
+  --> $DIR/liveness.rs:5:9
+   |
+LL | #![warn(unused)]
+   |         ^^^^^^
+   = note: `#[warn(unused_variables)]` implied by `#[warn(unused)]`
+   = help: did you mean to capture by reference instead?
+
+warning: value assigned to `a` is never read
+  --> $DIR/liveness.rs:52:9
+   |
+LL |         a += 1;
+   |         ^
+   |
+   = help: maybe it is overwritten before being read?
+
+warning: value assigned to `a` is never read
+  --> $DIR/liveness.rs:76:13
+   |
+LL |             a = Some("d1");
+   |             ^
+   |
+   = help: maybe it is overwritten before being read?
+
+warning: value assigned to `b` is never read
+  --> $DIR/liveness.rs:84:13
+   |
+LL |             b = Some("e1");
+   |             ^
+   |
+   = help: maybe it is overwritten before being read?
+
+warning: value assigned to `b` is never read
+  --> $DIR/liveness.rs:86:13
+   |
+LL |             b = Some("e2");
+   |             ^
+   |
+   = help: maybe it is overwritten before being read?
+
+warning: unused variable: `b`
+  --> $DIR/liveness.rs:84:13
+   |
+LL |             b = Some("e1");
+   |             ^
+   |
+   = help: did you mean to capture by reference instead?
+
+warning: 8 warnings emitted
+
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness_unintentional_copy.rs b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness_unintentional_copy.rs
new file mode 100644
index 00000000000..e2035464dfa
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness_unintentional_copy.rs
@@ -0,0 +1,42 @@
+// check-pass
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+#![warn(unused)]
+
+#[derive(Debug)]
+struct MyStruct {
+    a: i32,
+    b: i32,
+}
+
+pub fn unintentional_copy_one() {
+    let mut a = 1;
+    let mut last = MyStruct{ a: 1, b: 1};
+    let mut f = move |s| {
+        // This will not trigger a warning for unused variable
+        // as last.a will be treated as a Non-tracked place
+        last.a = s;
+        a = s;
+        //~^ WARN value assigned to `a` is never read
+        //~| WARN unused variable: `a`
+    };
+    f(2);
+    f(3);
+    f(4);
+}
+
+pub fn unintentional_copy_two() {
+    let mut a = 1;
+    let mut sum = MyStruct{ a: 1, b: 0};
+    (1..10).for_each(move |x| {
+        // This will not trigger a warning for unused variable
+        // as sum.b will be treated as a Non-tracked place
+        sum.b += x;
+        a += x; //~ WARN unused variable: `a`
+    });
+}
+
+fn main() {
+    unintentional_copy_one();
+    unintentional_copy_two();
+}
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness_unintentional_copy.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness_unintentional_copy.stderr
new file mode 100644
index 00000000000..35b0c22fc4f
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/liveness_unintentional_copy.stderr
@@ -0,0 +1,47 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/liveness_unintentional_copy.rs:2:12
+   |
+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: value assigned to `a` is never read
+  --> $DIR/liveness_unintentional_copy.rs:19:9
+   |
+LL |         a = s;
+   |         ^
+   |
+note: the lint level is defined here
+  --> $DIR/liveness_unintentional_copy.rs:4:9
+   |
+LL | #![warn(unused)]
+   |         ^^^^^^
+   = note: `#[warn(unused_assignments)]` implied by `#[warn(unused)]`
+   = help: maybe it is overwritten before being read?
+
+warning: unused variable: `a`
+  --> $DIR/liveness_unintentional_copy.rs:19:9
+   |
+LL |         a = s;
+   |         ^
+   |
+note: the lint level is defined here
+  --> $DIR/liveness_unintentional_copy.rs:4:9
+   |
+LL | #![warn(unused)]
+   |         ^^^^^^
+   = note: `#[warn(unused_variables)]` implied by `#[warn(unused)]`
+   = help: did you mean to capture by reference instead?
+
+warning: unused variable: `a`
+  --> $DIR/liveness_unintentional_copy.rs:35:9
+   |
+LL |         a += x;
+   |         ^
+   |
+   = help: did you mean to capture by reference instead?
+
+warning: 4 warnings emitted
+