TB: rename Active → Unique to match paper

Author: RalfJung

src/borrow_tracker/tree_borrows/diagnostics.rs

@@ -244,8 +244,8 @@ pub(super) enum TransitionError {
     ChildAccessForbidden(Permission),
     /// A protector was triggered due to an invalid transition that loses
     /// too much permissions.
-    /// For example, if a protected tag goes from `Active` to `Disabled` due
-    /// to a foreign write this will produce a `ProtectedDisabled(Active)`.
+    /// For example, if a protected tag goes from `Unique` to `Disabled` due
+    /// to a foreign write this will produce a `ProtectedDisabled(Unique)`.
     /// This kind of error can only occur on foreign accesses.
     ProtectedDisabled(Permission),
     /// Cannot deallocate because some tag in the allocation is strongly protected.

src/borrow_tracker/tree_borrows/perms.rs

@@ -57,7 +57,7 @@ pub(super) struct LocationState {
 impl LocationState {
     /// Constructs a new initial state. It has neither been accessed, nor been subjected
     /// to any foreign access yet.
-    /// The permission is not allowed to be `Active`.
+    /// The permission is not allowed to be `Unique`.
     /// `sifa` is the (strongest) idempotent foreign access, see `foreign_access_skipping.rs`
     pub fn new_non_accessed(permission: Permission, sifa: IdempotentForeignAccess) -> Self {
         assert!(permission.is_initial() || permission.is_disabled());
@@ -80,7 +80,7 @@ impl LocationState {
     /// Check if the state can exist as the initial permission of a pointer.
     ///
     /// Do not confuse with `is_accessed`, the two are almost orthogonal
-    /// as apart from `Active` which is not initial and must be accessed,
+    /// as apart from `Unique` which is not initial and must be accessed,
     /// any other permission can have an arbitrary combination of being
     /// initial/accessed.
     /// FIXME: when the corresponding `assert` in `tree_borrows/mod.rs` finally
@@ -170,7 +170,7 @@ impl LocationState {
             }
             if self.permission.is_frozen() && access_kind == AccessKind::Read {
                 // A foreign read to a `Frozen` tag will have almost no observable effect.
-                // It's a theorem that `Frozen` nodes have no active children, so all children
+                // It's a theorem that `Frozen` nodes have no `Unique` children, so all children
                 // already survive foreign reads. Foreign reads in general have almost no
                 // effect, the only further thing they could do is make protected `Reserved`
                 // nodes become conflicted, i.e. make them reject child writes for the further
@@ -265,7 +265,7 @@ pub(super) struct Node {
     pub children: SmallVec<[UniIndex; 4]>,
     /// Either `Reserved`,  `Frozen`, or `Disabled`, it is the permission this tag will
     /// lazily be initialized to on the first access.
-    /// It is only ever `Disabled` for a tree root, since the root is initialized to `Active` by
+    /// It is only ever `Disabled` for a tree root, since the root is initialized to `Unique` by
     /// its own separate mechanism.
     default_initial_perm: Permission,
     /// The default initial (strongest) idempotent foreign access.
@@ -598,14 +598,14 @@ impl Tree {
         };
         let rperms = {
             let mut perms = UniValMap::default();
-            // We manually set it to `Active` on all in-bounds positions.
-            // We also ensure that it is accessed, so that no `Active` but
+            // We manually set it to `Unique` on all in-bounds positions.
+            // We also ensure that it is accessed, so that no `Unique` but
             // not yet accessed nodes exist. Essentially, we pretend there
-            // was a write that initialized these to `Active`.
+            // was a write that initialized these to `Unique`.
             perms.insert(
                 root_idx,
                 LocationState::new_accessed(
-                    Permission::new_active(),
+                    Permission::new_unique(),
                     IdempotentForeignAccess::None,
                 ),
             );
@@ -790,7 +790,7 @@ impl<'tcx> Tree {
     /// - the access will be applied only to accessed locations of the allocation,
     /// - it will not be visible to children,
     /// - it will be recorded as a `FnExit` diagnostic access
-    /// - and it will be a read except if the location is `Active`, i.e. has been written to,
+    /// - and it will be a read except if the location is `Unique`, i.e. has been written to,
     ///   in which case it will be a write.
     ///
     /// `LocationState::perform_access` will take care of raising transition

src/borrow_tracker/tree_borrows/tree.rs

@@ -420,7 +420,7 @@ mod spurious_read {
     /// `(LocStateProt, LocStateProt)` where the two states are not guaranteed
     /// to be updated at the same time.
     /// Some `LocStateProtPair` may be unreachable through normal means
-    /// such as `x: Active, y: Active` in the case of mutually foreign pointers.
+    /// such as `x: Unique, y: Unique` in the case of mutually foreign pointers.
     struct LocStateProtPair {
         xy_rel: RelPosXY,
         x: LocStateProt,
@@ -709,7 +709,7 @@ mod spurious_read {
         let mut err = 0;
         for pat in Pattern::exhaustive() {
             let Ok(initial_source) = pat.initial_state() else {
-                // Failed to retag `x` in the source (e.g. `y` was protected Active)
+                // Failed to retag `x` in the source (e.g. `y` was protected Unique)
                 continue;
             };
             // `x` must stay protected, but the function protecting `y` might return here

src/borrow_tracker/tree_borrows/tree/tests.rs

@@ -16,7 +16,7 @@ LL | |             Poll::<()>::Pending
 LL | |         })
 LL | |         .await
    | |______________^
-help: the accessed tag <TAG> later transitioned to Active due to a child write access at offsets [OFFSET]
+help: the accessed tag <TAG> later transitioned to Unique due to a child write access at offsets [OFFSET]
   --> tests/fail/async-shared-mutable.rs:LL:CC
    |
 LL |             *x = 1;

tests/fail/async-shared-mutable.tree.stderr

@@ -7,7 +7,7 @@ LL |     *y
    = help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
    = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/tree-borrows.md for further information
    = help: the accessed tag <TAG> is foreign to the protected tag <TAG> (i.e., it is not a child)
-   = help: this foreign read access would cause the protected tag <TAG> (currently Active) to become Disabled
+   = help: this foreign read access would cause the protected tag <TAG> (currently Unique) to become Disabled
    = help: protected tags must never be Disabled
 help: the accessed tag <TAG> was created here
   --> tests/fail/both_borrows/box_noalias_violation.rs:LL:CC
@@ -19,7 +19,7 @@ help: the protected tag <TAG> was created here, in the initial state Reserved
    |
 LL | unsafe fn test(mut x: Box<i32>, y: *const i32) -> i32 {
    |                ^^^^^
-help: the protected tag <TAG> later transitioned to Active due to a child write access at offsets [0x0..0x4]
+help: the protected tag <TAG> later transitioned to Unique due to a child write access at offsets [0x0..0x4]
   --> tests/fail/both_borrows/box_noalias_violation.rs:LL:CC
    |
 LL |     *x = 5;

tests/fail/both_borrows/box_noalias_violation.tree.stderr

@@ -7,7 +7,7 @@ LL |     unsafe { *y = 2 };
    = help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
    = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/tree-borrows.md for further information
    = help: the accessed tag <TAG> is foreign to the protected tag <TAG> (i.e., it is not a child)
-   = help: this foreign write access would cause the protected tag <TAG> (currently Active) to become Disabled
+   = help: this foreign write access would cause the protected tag <TAG> (currently Unique) to become Disabled
    = help: protected tags must never be Disabled
 help: the accessed tag <TAG> was created here
   --> tests/fail/both_borrows/illegal_write6.rs:LL:CC
@@ -19,7 +19,7 @@ help: the protected tag <TAG> was created here, in the initial state Reserved
    |
 LL | fn foo(a: &mut u32, y: *mut u32) -> u32 {
    |        ^
-help: the protected tag <TAG> later transitioned to Active due to a child write access at offsets [0x0..0x4]
+help: the protected tag <TAG> later transitioned to Unique due to a child write access at offsets [0x0..0x4]
   --> tests/fail/both_borrows/illegal_write6.rs:LL:CC
    |
 LL |     *a = 1;

tests/fail/both_borrows/illegal_write6.tree.stderr

@@ -7,7 +7,7 @@ LL |             Call(_unit = callee(Move(non_copy), Move(non_copy)), ReturnTo(a
    = help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
    = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/tree-borrows.md for further information
    = help: the accessed tag <TAG> (root of the allocation) is foreign to the protected tag <TAG> (i.e., it is not a child)
-   = help: this foreign read access would cause the protected tag <TAG> (currently Active) to become Disabled
+   = help: this foreign read access would cause the protected tag <TAG> (currently Unique) to become Disabled
    = help: protected tags must never be Disabled
 help: the accessed tag <TAG> was created here
   --> tests/fail/function_calls/arg_inplace_locals_alias.rs:LL:CC
@@ -19,7 +19,7 @@ help: the protected tag <TAG> was created here, in the initial state Reserved
    |
 LL |     y.0 = 0;
    |     ^^^^^^^
-help: the protected tag <TAG> later transitioned to Active due to a child write access at offsets [0x0..0x4]
+help: the protected tag <TAG> later transitioned to Unique due to a child write access at offsets [0x0..0x4]
   --> tests/fail/function_calls/arg_inplace_locals_alias.rs:LL:CC
    |
 LL |     y.0 = 0;

tests/fail/function_calls/arg_inplace_locals_alias.tree.stderr

@@ -7,7 +7,7 @@ LL |             Call(_non_copy = callee(Move(_non_copy)), ReturnTo(after_call),
    = help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
    = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/tree-borrows.md for further information
    = help: the accessed tag <TAG> (root of the allocation) is foreign to the protected tag <TAG> (i.e., it is not a child)
-   = help: this reborrow (acting as a foreign read access) would cause the protected tag <TAG> (currently Active) to become Disabled
+   = help: this reborrow (acting as a foreign read access) would cause the protected tag <TAG> (currently Unique) to become Disabled
    = help: protected tags must never be Disabled
 help: the accessed tag <TAG> was created here
   --> tests/fail/function_calls/arg_inplace_locals_alias_ret.rs:LL:CC
@@ -19,7 +19,7 @@ help: the protected tag <TAG> was created here, in the initial state Reserved
    |
 LL |     x
    |     ^
-help: the protected tag <TAG> later transitioned to Active due to a child write access at offsets [0x0..0x4]
+help: the protected tag <TAG> later transitioned to Unique due to a child write access at offsets [0x0..0x4]
   --> tests/fail/function_calls/arg_inplace_locals_alias_ret.rs:LL:CC
    |
 LL |     x

tests/fail/function_calls/arg_inplace_locals_alias_ret.tree.stderr

@@ -7,7 +7,7 @@ LL |     unsafe { ptr.write(S(0)) };
    = help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
    = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/tree-borrows.md for further information
    = help: the accessed tag <TAG> (root of the allocation) is foreign to the protected tag <TAG> (i.e., it is not a child)
-   = help: this foreign write access would cause the protected tag <TAG> (currently Active) to become Disabled
+   = help: this foreign write access would cause the protected tag <TAG> (currently Unique) to become Disabled
    = help: protected tags must never be Disabled
 help: the accessed tag <TAG> was created here
   --> tests/fail/function_calls/arg_inplace_mutate.rs:LL:CC
@@ -24,7 +24,7 @@ help: the protected tag <TAG> was created here, in the initial state Reserved
    |
 LL |     unsafe { ptr.write(S(0)) };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: the protected tag <TAG> later transitioned to Active due to a child write access at offsets [0x0..0x4]
+help: the protected tag <TAG> later transitioned to Unique due to a child write access at offsets [0x0..0x4]
   --> tests/fail/function_calls/arg_inplace_mutate.rs:LL:CC
    |
 LL |     unsafe { ptr.write(S(0)) };