This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md
The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:
* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
are now gone. These two methods are replaced with a `CString::from_slice`
method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
guarantee that there is a trailing nul byte with no internal nul bytes. This
means that `CString` now implements `Deref<Target = [c_char]>`, which is where
it gains most of its methods from. A few helper methods are added to acquire a
slice of `u8` instead of `c_char`, as well as including a slice with the
trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
functions are now the one method used to convert a `*const c_char` to a Rust
slice of `u8`.
Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:
[breaking-change]
Closes#20444
The previous scheme made it possible for another user/attacker to cause the
temporary directory creation scheme to panic. All you needed to know was the pid
of the process you wanted to target ('other_pid') and the suffix it was using
(let's pretend it's 'sfx') and then code such as this would, in essence, DOS it:
for i in range(0u, 1001) {
let tp = &Path::new(format!("/tmp/rs-{}-{}-sfx", other_pid, i));
match fs::mkdir(tp, io::USER_RWX) { _ => () }
}
Since the scheme only 1000 times to create a temporary directory before dying,
the next time the attacked process called TempDir::new("sfx") after that would
typically cause a panic. Of course, you don't necessarily need an attacker to
cause such a DOS: creating 1000 temporary directories without closing any of the
previous would be enough to DOS yourself.
This patch broadly follows the OpenBSD implementation of mkstemp. It uses the
operating system's random number generator to produce random directory names
that are impractical to guess (and, just in case someone manages to do that, it
retries creating the directory for a long time before giving up; OpenBSD
retries INT_MAX times, although 1<<31 seems enough to thwart even the most
patient attacker).
As a small additional change while the file name is changing, this patch also
makes the argument that TempDir::new takes a prefix rather than a suffix.
This is because 1) it more closely matches what mkstemp and friends do 2)
if you're going to have a deterministic part of a filename, you really want it at
the beginning so that shell completion is useful.
* Implement (derive) `Clone` for `ChaChaRng`, `Isaac*Rng`, `StdRng` and `ThreadRng`;
* Derive `XorShiftRng` `Clone` implementation instead of implementing it explicitly.
`OsRng` is the only Rng which does not implement `Clone` or `Copy` after this patch because of its dependence on `Reader`.
r? @huonw I guess?
macro_rules! is like an item that defines a macro. Other items don't have a
trailing semicolon, or use a paren-delimited body.
If there's an argument for matching the invocation syntax, e.g. parentheses for
an expr macro, then I think that applies more strongly to the *inner*
delimiters on the LHS, wrapping the individual argument patterns.
The earlier collections stabilization did not cover the modules
themselves. This commit marks as stable those modules whose types have
been stabilized.
Many of libstd's macros are now re-exported from libcore and libcollections.
Their libstd definitions have moved to a macros_stage0 module and can disappear
after the next snapshot.
Where the two crates had already diverged, I took the libstd versions as
they're generally newer and better-tested. See e.g. d3c831b, which was a fix to
libstd's assert_eq!() that didn't make it into libcore's.
Fixes#16806.
This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md
The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:
* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
are now gone. These two methods are replaced with a `CString::from_slice`
method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
guarantee that there is a trailing nul byte with no internal nul bytes. This
means that `CString` now implements `Deref<Target = [c_char]>`, which is where
it gains most of its methods from. A few helper methods are added to acquire a
slice of `u8` instead of `c_char`, as well as including a slice with the
trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
functions are now the one method used to convert a `*const c_char` to a Rust
slice of `u8`.
Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:
[breaking-change]
Closes#20444
The previous scheme made it possible for another user/attacker to cause the
temporary directory creation scheme to panic. All you needed to know was the pid
of the process you wanted to target ('other_pid') and the suffix it was using
(let's pretend it's 'sfx') and then code such as this would, in essence, DOS it:
for i in range(0u, 1001) {
let tp = &Path::new(format!("/tmp/rs-{}-{}-sfx", other_pid, i));
match fs::mkdir(tp, io::USER_RWX) { _ => () }
}
Since the scheme retried only 1000 times to create a temporary directory before
dying, the next time the attacked process called TempDir::new("sfx") after that
would typically cause a panic. Of course, you don't necessarily need an attacker
to cause such a DOS: creating 1000 temporary directories without closing any of
the previous would be enough to DOS yourself.
This patch broadly follows the OpenBSD implementation of mkstemp. It uses the
operating system's random number generator to produce random directory names
that are impractical to guess (and, just in case someone manages to do that, it
retries creating the directory for a long time before giving up; OpenBSD
retries INT_MAX times, although 1<<31 seems enough to thwart even the most
patient attacker).
As a small additional change, this patch also makes the argument that
TempDir::new takes a prefix rather than a suffix. This is because 1) it more
closely matches what mkstemp and friends do 2) if you're going to have a
deterministic part of a filename, you really want it at the beginning so that
shell completion is useful.
* The `sync` module is stable
* The `sync::mpsc` module is stable
* The `Sender::send` method is stable.
* The `Once::doit` method is now removed.
* Deprecated atomic initializers are removed.
* Renamed atomic initializers are now stable.
cc #19260
The casing transformations are left unstable (it is highly likely to be better to adopt the proper non-1-to-1 case mappings, per #20333) as are `is_xid_*`.
I've got a little todo list in the last commit of things I thought about/was told about that I haven't yet handled (I'd also like some feedback).
This "reexports" all the functionality of `core::char::CharExt` as
methods on `unicode::u_char::UnicodeChar` (renamed to `CharExt`).
Imports may need to be updated (one now just imports
`unicode::CharExt`, or `std::char::CharExt` rather than two traits from
either), so this is a
[breaking-change]
TODOs:
- ~~Entry is still `<'a, K, V>` instead of `<'a, O, V>`~~
- ~~BTreeMap is still outstanding~~.
- ~~Transform appropriate things into `.entry(...).get().or_else(|e| ...)`~~
Things that make me frowny face:
- I'm not happy about the fact that this `clone`s the key even when it's already owned.
- With small keys (e.g. `int`s), taking a reference seems wasteful.
r? @Gankro
cc: @cgaebel
