rust/tests/fail/stacked_borrows/illegal_write6.stderr

error: Undefined Behavior: not granting access to tag <TAG> because incompatible item is protected: [Unique for <TAG>] (call ID)
  --> $DIR/illegal_write6.rs:LL:CC
   |
LL |     unsafe { *y = 2 };
   |              ^^^^^^ not granting access to tag <TAG> because incompatible item is protected: [Unique for <TAG>] (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/illegal_write6.rs:LL:CC
   |
LL |     let p = x as *mut u32;
   |             ^
help: <TAG> was protected due to <TAG> which was created here
  --> $DIR/illegal_write6.rs:LL:CC
   |
LL |     foo(x, p);
   |         ^
help: this protector is live for this call
  --> $DIR/illegal_write6.rs:LL:CC
   |
LL | / fn foo(a: &mut u32, y: *mut u32) -> u32 {
LL | |     *a = 1;
LL | |     let _b = &*a;
LL | |     unsafe { *y = 2 };
LL | |     return *a;
LL | | }
   | |_^
   = note: backtrace:
   = note: inside `foo` at $DIR/illegal_write6.rs:LL:CC
note: inside `main` at $DIR/illegal_write6.rs:LL:CC
  --> $DIR/illegal_write6.rs:LL:CC
   |
LL |     foo(x, p);
   |     ^^^^^^^^^

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error
Store protectors outside Item, pack Tag and Perm Previously, Item was a struct of a NonZeroU64, an Option which was usually unset or irrelevant, and a 4-variant enum. So collectively, the size of an Item was 24 bytes, but only 8 bytes were used for the most part. So this takes advantage of the fact that it is probably impossible to exhaust the total space of SbTags, and steals 3 bits from it to pack the whole struct into a single u64. This bit-packing means that we reduce peak memory usage when Miri goes memory-bound by ~3x. We also get CPU performance improvements of varying size, because not only are we simply accessing less memory, we can now compare a Vec<Item> using a memcmp because it does not have any padding. 2022-07-02 13:38:23 -05:00			`error: Undefined Behavior: not granting access to tag <TAG> because incompatible item is protected: [Unique for <TAG>] (call ID)`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			`--> $DIR/illegal_write6.rs:LL:CC`
			`\|`
make a bunch of tests look more like how they did before rustfmt 2022-06-25 22:30:29 -05:00			`LL \| unsafe { *y = 2 };`
Store protectors outside Item, pack Tag and Perm Previously, Item was a struct of a NonZeroU64, an Option which was usually unset or irrelevant, and a 4-variant enum. So collectively, the size of an Item was 24 bytes, but only 8 bytes were used for the most part. So this takes advantage of the fact that it is probably impossible to exhaust the total space of SbTags, and steals 3 bits from it to pack the whole struct into a single u64. This bit-packing means that we reduce peak memory usage when Miri goes memory-bound by ~3x. We also get CPU performance improvements of varying size, because not only are we simply accessing less memory, we can now compare a Vec<Item> using a memcmp because it does not have any padding. 2022-07-02 13:38:23 -05:00			`\| ^^^^^^ not granting access to tag <TAG> because incompatible item is protected: [Unique for <TAG>] (call ID)`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			`\|`
bless 2022-06-12 00:34:01 -05:00			`= help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			`= help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information`
make permissive provenance and raw-ptr tagging the default 2022-06-26 20:14:18 -05:00			`help: <TAG> was created by a retag at offsets [0x0..0x4]`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			`--> $DIR/illegal_write6.rs:LL:CC`
			`\|`
			`LL \| let p = x as *mut u32;`
			`\| ^`
make permissive provenance and raw-ptr tagging the default 2022-06-26 20:14:18 -05:00			`help: <TAG> was protected due to <TAG> which was created here`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			`--> $DIR/illegal_write6.rs:LL:CC`
			`\|`
			`LL \| foo(x, p);`
			`\| ^`
			`help: this protector is live for this call`
			`--> $DIR/illegal_write6.rs:LL:CC`
			`\|`
			`LL \| / fn foo(a: &mut u32, y: *mut u32) -> u32 {`
			`LL \| \| *a = 1;`
			`LL \| \| let _b = &*a;`
make a bunch of tests look more like how they did before rustfmt 2022-06-25 22:30:29 -05:00			`LL \| \| unsafe { *y = 2 };`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			`LL \| \| return *a;`
			`LL \| \| }`
			`\| \|_^`
pointer tag tracking: on creation, log the offsets it is created for 2022-07-02 09:11:39 -05:00			`= note: backtrace:`
Add a custom ui test runner and move all tests to it 2022-03-17 08:49:10 -05:00			= note: inside `foo` at $DIR/illegal_write6.rs:LL:CC
			note: inside `main` at $DIR/illegal_write6.rs:LL:CC
			`--> $DIR/illegal_write6.rs:LL:CC`
			`\|`
			`LL \| foo(x, p);`
			`\| ^^^^^^^^^`

			note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

			`error: aborting due to previous error`