Valgrind error
```
==132117== Thread 9 map::test_map:::
==132117== Conditional jump or move depends on uninitialised value(s)
==132117== at 0x139B47: alloc::raw_vec::RawVec::current_memory (raw_vec.rs:256)
==132117== by 0x1346DA: as core::ops::drop::Drop>::drop (raw_vec.rs:530)
==132117== by 0x131AC9: core::ptr::drop_in_place> (mod.rs:507)
==132117== by 0x1318AA: core::ptr::drop_in_place> (mod.rs:507)
==132117== by 0x132749: core::ptr::drop_in_place (mod.rs:507)
==132117== by 0x1302CD: core::ptr::drop_in_place<(i32,hashbrown::map::test_map::test_clone_from_memory_leaks::CheckedClone)> (mod.rs:507)
==132117== by 0x178D4A: drop_in_place<(i32, hashbrown::map::test_map::test_clone_from_memory_leaks::CheckedClone)> (mut_ptr.rs:1469)
==132117== by 0x178D4A: hashbrown::raw::Bucket::drop (mod.rs:590)
==132117== by 0x1CBE07: hashbrown::raw::RawTable::clone_from_impl::{{closure}} (mod.rs:3587)
==132117== by 0x135531: as core::ops::drop::Drop>::drop (scopeguard.rs:70)
==132117== by 0x1313D9: core::ptr::drop_in_place),hashbrown::raw::RawTable<(i32,hashbrown::map::test_map::test_clone_from_memory_leaks::CheckedClone)>::clone_from_impl::{{closure}}>> (mod.rs:507)
==132117== by 0x1CB124: hashbrown::raw::RawTable::clone_from_impl (mod.rs:3607)
==132117== by 0x1D4532: as hashbrown::raw::RawTableClone>::clone_from_spec (mod.rs:3545)
==132117==
```
Miri also fails:
cargo +nightly miri test map::test_map::test_clone_from_memory_leaks
MIRI error
```
test map::test_map::test_clone_from_memory_leaks - should panic ... error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
--> /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/raw_vec.rs:235:9
|
235 | self.ptr.as_ptr()
| ^^^^^^^^ using uninitialized data, but this operation requires initialized memory
|
= help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
= help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
= note: BACKTRACE on thread `map::test_map::`:
= note: inside `alloc::raw_vec::RawVec::::ptr` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/raw_vec.rs:235:9: 235:17
= note: inside `std::vec::Vec::::as_mut_ptr` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/vec/mod.rs:1331:9: 1331:23
= note: inside ` as core::ops::Drop>::drop` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/vec/mod.rs:3171:62: 3171:79
= note: inside `core::ptr::drop_in_place::> - shim(Some(std::vec::Vec))` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:515:1: 515:56
= note: inside `core::ptr::drop_in_place:: - shim(Some(map::test_map::test_clone_from_memory_leaks::CheckedClone))` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:515:1: 515:56
= note: inside `core::ptr::drop_in_place::<(i32, map::test_map::test_clone_from_memory_leaks::CheckedClone)> - shim(Some((i32, map::test_map::test_clone_from_memory_leaks::CheckedClone)))` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:515:1: 515:56
= note: inside `core::ptr::mut_ptr::::drop_in_place` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mut_ptr.rs:1473:18: 1473:37
note: inside `raw::Bucket::<(i32, map::test_map::test_clone_from_memory_leaks::CheckedClone)>::drop`
--> src/raw/mod.rs:590:9
|
590 | self.as_ptr().drop_in_place();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: inside closure
--> src/raw/mod.rs:3587:25
|
3587 | self_.bucket(i).drop();
| ^^^^^^^^^^^^^^^^^^^^^^
note: inside `), {closure@src/raw/mod.rs:3583:48: 3583:64}> as core::ops::Drop>::drop`
--> src/scopeguard.rs:70:9
|
70 | (self.dropfn)(&mut self.value);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: inside `core::ptr::drop_in_place::), {closure@src/raw/mod.rs:3583:48: 3583:64}>> - shim(Some(scopeguard::ScopeGuard<(usize, &mut raw::RawTable<(i32, map::test_map::test_clone_from_memory_leaks::CheckedClone)>), {closure@src/raw/mod.rs:3583:48: 3583:64}>))` at /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:515:1: 515:56
note: inside `raw::RawTable::<(i32, map::test_map::test_clone_from_memory_leaks::CheckedClone)>::clone_from_impl`
--> src/raw/mod.rs:3607:5
|
3607 | }
| ^
note: inside ` as raw::RawTableClone>::clone_from_spec`
--> src/raw/mod.rs:3545:13
|
3545 | self.clone_from_impl(source);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: inside ` as core::clone::Clone>::clone`
--> src/raw/mod.rs:3464:17
|
3464 | new_table.clone_from_spec(self);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: inside ` as core::clone::Clone>::clone`
--> src/map.rs:199:20
|
199 | table: self.table.clone(),
| ^^^^^^^^^^^^^^^^^^
note: inside `map::test_map::test_clone_from_memory_leaks`
--> src/map.rs:8566:21
|
8566 | let _map2 = map1.clone();
| ^^^^^^^^^^^^
note: inside closure
--> src/map.rs:8526:38
|
8524 | #[test]
| ------- in this procedural macro expansion
8525 | #[should_panic = "panic in clone"]
8526 | fn test_clone_from_memory_leaks() {
| ^
= note: this error originates in the attribute macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)
```
I've encountered memory corruption in tests of a fork of hashbrown which might or might not be related. While trying to track down the root cause I noted that the above was also present here. I've not investigated deeper but the test case itself is implemented without unsafe.
Steps to reproduce:
Find the resulting test binary and run it through valgrind:
This is what I get:
Valgrind error
``` ==132117== Thread 9 map::test_map::: ==132117== Conditional jump or move depends on uninitialised value(s) ==132117== at 0x139B47: alloc::raw_vec::RawVecMiri also fails:
MIRI error
``` test map::test_map::test_clone_from_memory_leaks - should panic ... error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory --> /home/udoprog/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/raw_vec.rs:235:9 | 235 | self.ptr.as_ptr() | ^^^^^^^^ using uninitialized data, but this operation requires initialized memory | = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information = note: BACKTRACE on thread `map::test_map::`: = note: inside `alloc::raw_vec::RawVec::I've encountered memory corruption in tests of a fork of hashbrown which might or might not be related. While trying to track down the root cause I noted that the above was also present here. I've not investigated deeper but the test case itself is implemented without
unsafe.