Added minor clarification to specification of GlobalAlloc::realloc. #68381
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The `layout` for the returned allocation of a `realloc` is only implicitly specified. This change makes it explicit.
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Added minor clarification to specification of GlobalAlloc::realloc.
The specification of `realloc` is slightly unclear:
```
/// * `layout` must be the same layout that was used
/// to allocate that block of memory,
```
https://github.com/rust-lang/rust/blob/master/src/libcore/alloc.rs#L541-L542
In the case of an `alloc` or `alloc_zeroed` this is fairly evidently the `layout` parameter passed into the original call. In the case of a `realloc`, this I assume is `layout` modified to contain `new_size`. However, I could not find this case specified in the documentation. Thus technically in a sequence of calls to `realloc`, it would be valid to provide the second call to `realloc` the same `layout` as the first call to `realloc`, which is almost certainly not going to be handled correctly.
This PR attempts to clarify the specification.
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Added minor clarification to specification of GlobalAlloc::realloc.
The specification of `realloc` is slightly unclear:
```
/// * `layout` must be the same layout that was used
/// to allocate that block of memory,
```
https://github.com/rust-lang/rust/blob/master/src/libcore/alloc.rs#L541-L542
In the case of an `alloc` or `alloc_zeroed` this is fairly evidently the `layout` parameter passed into the original call. In the case of a `realloc`, this I assume is `layout` modified to contain `new_size`. However, I could not find this case specified in the documentation. Thus technically in a sequence of calls to `realloc`, it would be valid to provide the second call to `realloc` the same `layout` as the first call to `realloc`, which is almost certainly not going to be handled correctly.
This PR attempts to clarify the specification.
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Rollup of 8 pull requests Successful merges: - #67734 (Remove appendix from Apache license) - #67795 (Cleanup formatting code) - #68290 (Fix some tests failing in `--pass check` mode) - #68297 ( Filter and test predicates using `normalize_and_test_predicates` for const-prop) - #68302 (Fix #[track_caller] and function pointers) - #68339 (Add `riscv64gc-unknown-linux-gnu` into target list in build-manifest) - #68381 (Added minor clarification to specification of GlobalAlloc::realloc.) - #68397 (rustdoc: Correct order of `async` and `unsafe` in `async unsafe fn`s) Failed merges: r? @ghost
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The specification of
reallocis slightly unclear:https://github.com/rust-lang/rust/blob/master/src/libcore/alloc.rs#L541-L542
In the case of an
allocoralloc_zeroedthis is fairly evidently thelayoutparameter passed into the original call. In the case of arealloc, this I assume islayoutmodified to containnew_size. However, I could not find this case specified in the documentation. Thus technically in a sequence of calls torealloc, it would be valid to provide the second call toreallocthe samelayoutas the first call torealloc, which is almost certainly not going to be handled correctly.This PR attempts to clarify the specification.