Clarify the English translation of `?Sized`
* It wasn't clear whether `?Sized` meant "not `Sized`" or "`Sized` or not `Sized`". According to #rust IRC, it does indeed mean "`Sized` or not `Sized`".
* Use the same language as [Trait std::marker::Sized](https://doc.rust-lang.org/std/marker/trait.Sized.html) about how `Sized` is implicitly bound.
* Refer to the syntax as `?Sized`, since it's currently the only allowed trait that can follow `?`.
Book: small improvement to a table to make it clearer
This table is used as an example of four heap values where two of them got deallocated leaving a gap.
It also has stack variables.
Instead of four stack variables I propose three, that way there's no misleading connection between the number of stack variables and heap variables.
But more importantly: three of the four stack variables had the same name (**y**) which could be confusing to a beginner, I changed this as well.
rustdoc: Add doc snippets for trait impls, with a read more link
The read more link only appears if the documentation is more than one line long.
It currently does not appear on non-defaulted methods, since you can document them directly. I could make it so that default documentation gets forwarded if regular docs don't exist.
Fixes#33672
r? @alexcrichton
cc @steveklabnik
rustbuild: Touch up some test suites
This adds in some missing test suites, primarily a few pretty suites. It also starts optimizing tests by default as the current test suite does, but also recognizes `--disable-optimize-tests`.
Currently the optimization of tests isn't recognized by crate tests because Cargo doesn't support the ability to compile an unoptimized test suite against an optimized library. Perhaps a feature to add, though!
* Use "special bound syntax" instead of "special syntax". `?Sized` is technically a "bound", but `?Sized` is specialized syntax that _only_ works with `Sized`, and no other Trait.
* Replace "constant size" with "sized".
Originally fixed in #29961 the bug was unfortunately still present in the face
of crates using `#[macro_use]`. This commit refactors for the two code paths to
share common logic to ensure that they both pick up the same bug fix.
Closes#33762
std: Cache HashMap keys in TLS
This is a rebase and extension of #31356 where we not only cache the keys in
thread local storage but we also bump each key every time a new `HashMap` is
created. This should give us a nice speed bost in creating hash maps along with
retaining the property that all maps have a nondeterministic iteration order.
Closes#27243
* removed `on_all_children_bits`, rewriting calls to use `super::on_all_children_bits`
* moved `fn path` helper routine out of `impl MirBorrowckCtxtPreDataflow`
std: Backport a libbacktrace soundness fix
This is a backport of gcc-mirror/gcc@047a1c2f which is a soundness fix for when
a backtrace is generated on executables that do not have debug information.
rustc: Add a new crate type, cdylib
This commit is an implementation of [RFC 1510] which adds a new crate type,
`cdylib`, to the compiler. This new crate type differs from the existing `dylib`
crate type in a few key ways:
* No metadata is present in the final artifact
* Symbol visibility rules are the same as executables, that is only reachable
`extern` functions are visible symbols
* LTO is allowed
* All libraries are always linked statically
This commit is relatively simple by just plubming the compiler with another
crate type which takes different branches here and there. The only major change
is an implementation of the `Linker::export_symbols` function on Unix which now
actually does something. This helps restrict the public symbols from a cdylib on
Unix.
With this PR a "hello world" `cdylib` is 7.2K while the same `dylib` is 2.4MB,
which is some nice size savings!
[RFC 1510]: https://github.com/rust-lang/rfcs/pull/1510Closes#33132
