Fix wasi::fs::OpenOptions to imply write when append is on
This PR fixes a bug in `OpenOptions` of `wasi` platform that it currently doesn't imply write mode when only `append` is enabled.
As explained in the [doc of OpenOptions#append](https://doc.rust-lang.org/std/fs/struct.OpenOptions.html#method.append), calling `.append(true)` should imply `.write(true)` as well.
## Reproduce
Given below simple Rust program:
```rust
use std::fs::OpenOptions;
use std::io::Write;
fn main() {
let mut file = OpenOptions::new()
.write(true)
.create(true)
.open("foo.txt")
.unwrap();
writeln!(file, "abc").unwrap();
}
```
it can successfully compiled into wasm and execute by `wasmtime` runtime:
```sh
$ rustc --target wasm32-wasi write.rs
$ ~/wasmtime/target/debug/wasmtime run --dir=. write.wasm
$ cat foo.txt
abc
```
However when I change `.write(true)` to `.append(true)`, it fails to execute by the error "Capabilities insufficient":
```sh
$ ~/wasmtime/target/debug/wasmtime run --dir=. append.wasm
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 76, kind: Other, message: "Capabilities insufficient" }', append.rs:10:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: failed to run main module `append.wasm`
...
```
This is because of lacking "rights" on the opened file:
```sh
$ RUST_LOG=trace ~/wasmtime/target/debug/wasmtime run --dir=. append.wasm 2>&1 | grep validate_rights
TRACE wasi_common::entry > | validate_rights failed: required rights = HandleRights { base: fd_write (0x40), inheriting: empty (0x0) }; actual rights = HandleRights { base: fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_advise|fd_filestat_set_times|poll_fd_readwrite (0x88000bc), inheriting: empty (0x0) }
```
While debugging a codegen issue, I tried adding LLVM options with
the rustc -Cllvm-args option, and was confused by the error and usage
messaging.
The LLVM "program name" argument is set to "rustc", and command line
error messages make it look like invalid arguments are "rustc"
arguments, not LLVM.
I changed this argument so error messages and the "-help" usage feedback
is easier to understand and react to. (Clang does something similar.)
Put panic code path from `copy_from_slice` into cold function
The previous `assert_eq` generated quite some code, which is especially problematic when this call is inlined. This commit also slightly improves the panic message from:
assertion failed: `(left == right)`
left: `3`,
right: `2`: destination and source slices have different lengths
...to:
source slice length (2) does not match destination slice length (3)
You can see the code bloat in assembly [here](https://rust.godbolt.org/z/74a3qo).
Miri: improve spans of required_const failures
In https://github.com/rust-lang/rust/pull/75339 I added a loop evaluating all consts required by a function body. Unfortunately, if one of their evaluations fails, then the span used for that was that of the first statement in the function body, which happened to work form some existing test but is not sensible in general.
This PR changes it to point to the whole function instead, which is at least not wrong.
r? @oli-obk
The previous `assert_eq` generated quite some code, which is especially
problematic when this call is inlined. This commit also slightly
improves the panic message from:
assertion failed: `(left == right)`
left: `3`,
right: `2`: destination and source slices have different lengths
...to:
source slice length (2) does not match destination slice length (3)
Add Ipv6Addr::to_ipv4_mapped
* add Ipv6Addr::to_ipv4_mapped
* ~~deprecate Ipv4Addr::to_ipv6_compatible & Ipv6Addr::to_ipv4~~ reference: #75150
According to [IETF RFC 4291](https://tools.ietf.org/html/rfc4291#page-10), the "IPv4-Compatible IPv6 address" is deprecated.
> 2.5.5.1. IPv4-Compatible IPv6 Address
>
> The "IPv4-Compatible IPv6 address" was defined to assist in the IPv6
> transition. The format of the "IPv4-Compatible IPv6 address" is as
> follows:
>
> | 80 bits | 16 | 32 bits |
> +--------------------------------------+--------------------------+
> |0000..............................0000|0000| IPv4 address |
> +--------------------------------------+----+---------------------+
>
> Note: The IPv4 address used in the "IPv4-Compatible IPv6 address"
> must be a globally-unique IPv4 unicast address.
>
> The "IPv4-Compatible IPv6 address" is now deprecated because the
> current IPv6 transition mechanisms no longer use these addresses.
> New or updated implementations are not required to support this
> address type.
And the current implementation of `Ipv4Addr::to_ipv6_compatible`is incorrect: it does not check whether the IPv4 address is a globally-unique IPv4 unicast address.
Please let me know if there are any issues with this pull request.
Remove embedded-resources alumni from toolstate
Some people left the embedded-resources working group (https://github.com/rust-lang/team/pull/401), making them unassignable in toolstate issues. This PR removes them from the toolstate assignees list, fixing CI.
Handle projection predicates in the param env for auto-trait docs
Fixes#72213
Any predicates in the param env are guaranteed to hold, so we don't need
to do any additional processing of them if we come across them as
sub-obligations of a different predicate. This allows us to avoid adding
the same predicate to the computed ParamEnv multiple times (but with
different regions each time), which causes an ambiguity error during
fulfillment.
Rollup of 9 pull requests
Successful merges:
- #74521 (older toolchains not valid anymore)
- #74960 (Fix regionck failure when converting Index to IndexMut)
- #75234 (Update asm! documentation in unstable book)
- #75368 (Move to doc links inside the prelude)
- #75371 (Move to doc links inside std/time.rs)
- #75394 (Add a function to `TyCtxt` for computing an `Allocation` for a `static` item's initializer)
- #75395 (Switch to intra-doc links in library/std/src/os/*/fs.rs)
- #75422 (Accept more safety comments)
- #75424 (fix wrong word in documentation)
Failed merges:
r? @ghost
fix wrong word in documentation
Change "two" to "three", since there are three significantly different things printed below that sentence:
---
While these:
```rust
println!("{}, `{name:.*}` has 3 fractional digits", "Hello", 3, name=1234.56);
println!("{}, `{name:.*}` has 3 characters", "Hello", 3, name="1234.56");
println!("{}, `{name:>8.*}` has 3 right-aligned characters", "Hello", 3, name="1234.56");
```
print two significantly different things:
``` rust
Hello, `1234.560` has 3 fractional digits
Hello, `123` has 3 characters
Hello, ` 123` has 3 right-aligned characters
```
---
[`https://doc.rust-lang.org/std/fmt/#precision`](https://doc.rust-lang.org/std/fmt/#precision)
Accept more safety comments
This accepts more `// SAFETY:` comments from `tidy`.
This is done after the current behaviour of requiring text one the same line (because spaces are stripped so the last space never pass if there is no text on the same line) bit me once more in #75066
This could potentially accept empty `// SAFETY:` comments but `tidy` is an internal tool used only here so my reasoning is reviews will catch those.
