rust/tests/fail/stacked_borrows/invalidate_against_barrier2.stderr
Ben Kimock 4eff60ad6e Rearrange and document the new implementation
stacked_borrow now has an item module, and its own FrameExtra. These
serve to protect the implementation of Item (which is a bunch of
bit-packing tricks) from the primary logic of Stacked Borrows, and the
FrameExtra we have separates Stacked Borrows more cleanly from the
interpreter itself.

The new strategy for checking protectors also makes some subtle
performance tradeoffs, so they are now documented in Stack::item_popped
because that function primarily benefits from them, and it also touches
every aspect of them.

Also separating the actual CallId that is protecting a Tag from the Tag
makes it inconvienent to reproduce exactly the same protector errors, so
this also takes the opportunity to use some slightly cleaner English in
those errors. We need to make some change, might as well make it good.
2022-07-12 21:03:54 -04:00

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error: Undefined Behavior: not granting access to tag <TAG> because incompatible item [SharedReadOnly for <TAG>] is protected by call ID
--> $DIR/invalidate_against_barrier2.rs:LL:CC
|
LL | unsafe { *x = 0 };
| ^^^^^^ not granting access to tag <TAG> because incompatible item [SharedReadOnly for <TAG>] is protected by call ID
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental
= help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information
help: <TAG> was created by a retag at offsets [0x0..0x4]
--> $DIR/invalidate_against_barrier2.rs:LL:CC
|
LL | let xraw = &mut x as *mut _;
| ^^^^^^
help: <TAG> was protected due to <TAG> which was created here
--> $DIR/invalidate_against_barrier2.rs:LL:CC
|
LL | inner(xraw, xref);
| ^^^^
help: this protector is live for this call
--> $DIR/invalidate_against_barrier2.rs:LL:CC
|
LL | / fn inner(x: *mut i32, _y: &i32) {
LL | | // If `x` and `y` alias, retagging is fine with this... but we really
LL | | // shouldn't be allowed to write to `x` at all because `y` was assumed to be
LL | | // immutable for the duration of this call.
LL | | unsafe { *x = 0 };
LL | | }
| |_^
= note: backtrace:
= note: inside `inner` at $DIR/invalidate_against_barrier2.rs:LL:CC
note: inside `main` at $DIR/invalidate_against_barrier2.rs:LL:CC
--> $DIR/invalidate_against_barrier2.rs:LL:CC
|
LL | inner(xraw, xref);
| ^^^^^^^^^^^^^^^^^
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error