add support for the l4-bender linker on the x86_64-unknown-l4re-uclibc tier 3 target
This PR contains the work by ```@humenda``` to update support for the `x86_64-unknown-l4re-uclibc` tier 3 target (published at [humenda/rust](https://github.com/humenda/rust)), rebased and adapted to current rust in follow up commits by myself. The publishing of the rebased changes is authorized and preferred by the original author. As the goal was to distort the original work as little as possible, individual commits introduce changes that are incompatible to the newer code base that the changes were rebased on. These incompatibilities have been remedied in follow up commits, so that the PR as a whole should result in a clean update of the target.
If you prefer another strategy to mainline these changes while preserving attribution, please let me know.
`Decoder` has two impls:
- opaque: this impl is already partly infallible, i.e. in some places it
currently panics on failure (e.g. if the input is too short, or on a
bad `Result` discriminant), and in some places it returns an error
(e.g. on a bad `Option` discriminant). The number of places where
either happens is surprisingly small, just because the binary
representation has very little redundancy and a lot of input reading
can occur even on malformed data.
- json: this impl is fully fallible, but it's only used (a) for the
`.rlink` file production, and there's a `FIXME` comment suggesting it
should change to a binary format, and (b) in a few tests in
non-fundamental ways. Indeed #85993 is open to remove it entirely.
And the top-level places in the compiler that call into decoding just
abort on error anyway. So the fallibility is providing little value, and
getting rid of it leads to some non-trivial performance improvements.
Much of this commit is pretty boring and mechanical. Some notes about
a few interesting parts:
- The commit removes `Decoder::{Error,error}`.
- `InternIteratorElement::intern_with`: the impl for `T` now has the same
optimization for small counts that the impl for `Result<T, E>` has,
because it's now much hotter.
- Decodable impls for SmallVec, LinkedList, VecDeque now all use
`collect`, which is nice; the one for `Vec` uses unsafe code, because
that gave better perf on some benchmarks.
delete `Stdin::split` forwarder
Part of #87096. Delete the `Stdin::split` forwarder because it's seen as too niche to expose at this level.
`@rustbot` label T-libs-api A-io
Improve `Arc` and `Rc` documentation
This makes two changes (I can split the PR if necessary, but the changes are pretty small):
1. A bunch of trait implementations claimed to be zero cost; however, they use the `Arc<T>: From<Box<T>>` impl which is definitely not free, especially for large dynamically sized `T`.
2. The code in deferred initialization examples unnecessarily used excessive amounts of `unsafe`. This has been reduced.
Improve string concatenation suggestion
Before:
error[E0369]: cannot add `&str` to `&str`
--> file.rs:2:22
|
2 | let _x = "hello" + " world";
| ------- ^ -------- &str
| | |
| | `+` cannot be used to concatenate two `&str` strings
| &str
|
help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left
|
2 | let _x = "hello".to_owned() + " world";
| ~~~~~~~~~~~~~~~~~~
After:
error[E0369]: cannot add `&str` to `&str`
--> file.rs:2:22
|
2 | let _x = "hello" + " world";
| ------- ^ -------- &str
| | |
| | `+` cannot be used to concatenate two `&str` strings
| &str
|
= note: string concatenation requires an owned `String` on the left
help: create an owned `String` from a string reference
|
2 | let _x = "hello".to_owned() + " world";
| +++++++++++
Improve error message for key="value" cfg arguments.
Hi, I ran into difficulties using the `--cfg` flag syntax, first hit when googling for the error was issue https://github.com/rust-lang/rust/issues/66450. Reading that issue, it sounded like the best way to improve the experience was to improve the error message, this is low risk and doesn't introduce any additional argument parsing.
The issue mentions that it is entirely dependent on the shell, while this may be true, I think guiding the the user into the realization that the quotes may need to be escaped is helpful. The two suggested escapings both work in Bash and in the Windows command prompt.
fyi `@ehuss`
Ensure that early-bound function lifetimes are always 'local'
During borrowchecking, we treat any free (early-bound) regions on
the 'defining type' as `RegionClassification::External`. According
to the doc comments, we should only have 'external' regions when
checking a closure/generator.
However, a plain function can also have some if its regions
be considered 'early bound' - this occurs when the region is
constrained by an argument, appears in a `where` clause, or
in an opaque type. This was causing us to incorrectly mark these
regions as 'external', which caused some diagnostic code
to act as if we were referring to a 'parent' region from inside
a closure.
This PR marks all instantiated region variables as 'local'
when we're borrow-checking something other than a
closure/generator/inline-const.
Add more granular `--exclude` in `x.py`
x.py has support for excluding some steps from the current invocation, but unfortunately that's not granular enough: some steps have the same name in different modules, and that prevents excluding only *some* of them.
As a practical example, let's say you need to run everything in `./x.py test` except for the standard library tests, as those tests require IPv6 and need to be executed on a separate machine. Before this commit, if you were to just run this:
./x.py test --exclude library/std
...the invocation would eventually fail, as that would not only exclude running the tests for the standard library (`library/std` in the `test` module), it would also exclude generating its documentation (`library/std` in the `doc` module), breaking linkchecker.
This commit adds support to the `--exclude` flag for prefixing paths with the name of the module their step is defined in, allowing the user to choose which module to exclude from:
./x.py test --exclude test::library/std
This maintains backward compatibility with existing invocations, while allowing more ganular exclusion. Examples of the behavior:
| `--exclude` | Docs | Tests |
| ------------------- | ------- | ------- |
| `library/std` | Skipped | Skipped |
| `doc::library/std` | Skipped | Run |
| `test::library/std` | Run | Skipped |
Note that this PR only changes the `--exclude` flag, and not in other `x.py` arguments or flags yet.
In the implementation I tried to limit the impact this would have with rustbuild as a whole as much as possible. The module name is extracted from the step by parsing the result of `std::any::type_name()`: unfortunately that output can change at any point in time, but IMO it's better than having to annotate all the existing and future `Step` implementations with the module name. I added a test to ensure the parsing works as expected, so hopefully if anyone makes changes to the output of `std::any::type_name()` they'll also notice they have to update rustbuild.
r? `@Mark-Simulacrum`
Override rustc version in ui and mir-opt tests to get stable hashes
Building a dozen separate regexps for each test in compiletest consumes significant amounts of CPU cycles.
UI test timings on my machine:
OLD: 39.63s
NEW: 30.27s
Generator drop tracking caused an ICE for generators involving the Never
type (Issue #93161). Since this breaks miri, we temporarily disable drop
tracking so miri is unblocked while we properly fix the issue.
- Fix style errors.
- L4-bender does not yet support dynamic linking.
- Stack unwinding is not yet supported for x86_64-unknown-l4re-uclibc.
For now, just abort on panics.
- Use GNU-style linker options where possible. As suggested by review:
- Use standard GNU-style ld syntax for relro flags.
- Use standard GNU-style optimization flags and logic.
- Use standard GNU-style ld syntax for --subsystem.
- Don't read environment variables in L4Bender linker. Thanks to
CARGO_ENCODED_RUSTFLAGS introduced in #9601, l4-bender's arguments can
now be passed from the L4Re build system without resorting to custom
parsing of environment variables.
Update some rustc dependencies to deduplicate them
This PR updates `rand` and `itertools` in rustc (not the whole workspace) in order to deduplicate them (and hopefully slightly improve compile times).
~~Currently, `object` is still duplicated, but https://github.com/rust-lang/thorin/pull/15 and updating `thorin` in the future will remove the use of version 0.27.~~ Update: Thorin 0.2 has now been released, and this PR updates `rustc_codegen_ssa` to use it and deduplicate the `object` crate.
There's a final tiny rustc dependency, `cfg-if`, which will be left: as both versions 0.1.x and 1.0 looked to be heavily depended on, they will require a few cascading updates to be removed.
x.py has support for excluding some steps from the invocation, but
unfortunately that's not granular enough: some steps have the same name
in different modules, and that prevents excluding only *some* of them.
As a practical example, let's say you need to run everything in `./x.py
test` except for the standard library tests, as those tests require IPv6
and need to be executed on a separate machine. Before this commit, if
you were to just run this:
./x.py test --exclude library/std
...the execution would fail, as that would not only exclude running the
tests for the standard library, it would also exclude generating its
documentation (breaking linkchecker).
This commit adds support for an optional module annotation in --exclude
paths, allowing the user to choose which module to exclude from:
./x.py test --exclude test::library/std
This maintains backward compatibility, but also allows for more ganular
exclusion. More examples on how this works:
| `--exclude` | Docs | Tests |
| ------------------- | ------- | ------- |
| `library/std` | Skipped | Skipped |
| `doc::library/std` | Skipped | Run |
| `test::library/std` | Run | Skipped |
Note that the new behavior only works in the `--exclude` flag, and not
in other x.py arguments or flags yet.
I have found this code very confusing at times. This commit clarifies
things.
In particular, the commit explains the requirements that the `Borrow`
impls put on the `Eq` and `Hash` impls, which are non-obvious. And it
puts the `Borrow` impls first, since they force `Eq` and `Hash` to have
particular forms.
The commit also notes `TyS`'s uniqueness requirements.
Rollup of 17 pull requests
Successful merges:
- #91032 (Introduce drop range tracking to generator interior analysis)
- #92856 (Exclude "test" from doc_auto_cfg)
- #92860 (Fix errors on blanket impls by ignoring the children of generated impls)
- #93038 (Fix star handling in block doc comments)
- #93061 (Only suggest adding `!` to expressions that can be macro invocation)
- #93067 (rustdoc mobile: fix scroll offset when jumping to internal id)
- #93086 (Add tests to ensure that `let_chains` works with `if_let_guard`)
- #93087 (Fix src/test/run-make/raw-dylib-alt-calling-convention)
- #93091 (⬆ chalk to 0.76.0)
- #93094 (src/test/rustdoc-json: Check for `struct_field`s in `variant_tuple_struct.rs`)
- #93098 (Show a more informative panic message when `DefPathHash` does not exist)
- #93099 (rustdoc: auto create output directory when "--output-format json")
- #93102 (Pretty printer algorithm revamp step 3)
- #93104 (Support --bless for pp-exact pretty printer tests)
- #93114 (update comment for `ensure_monomorphic_enough`)
- #93128 (Add script to prevent point releases with same number as existing ones)
- #93136 (Backport the 1.58.1 release notes to master)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Transition unsupported naked functions future incompatibility lint into
an error:
* Naked functions must contain a single inline assembly block.
Introduced as future incompatibility lint in 1.50 #79653.
Change into an error fixes a soundness issue described in #32489.
* Naked functions must not use any forms of inline attribute.
Introduced as future incompatibility lint in 1.56 #87652.
Building a dozen separate regexps for each test in compiletest consumes significant amounts of CPU cycles.
Using `RUSTC_FORCE_INCR_COMP_ARTIFACT_HEADER` stabilizes hashes calcuated for the individual tests so
no test-dependent normalization is needed. Hashes for the standard library still change so some
normalizations are still needed.
Add script to prevent point releases with same number as existing ones
This will hopefully prevent what happened today with #93110 and #93121, where we built point release artifacts without changing version numbers, thus requiring another PR to change the version number.
r? `@Mark-Simulacrum`
