Stabilize `-Zdwarf-version` as `-Cdwarf-version`
I propose stabilizing `-Zdwarf-version` as `-Cdwarf-version`. This PR adds a new `-Cdwarf-version` flag, leaving the unstable `-Z` flag as is to ease the transition period. The `-Z` flag will be removed in the future.
# `-Zdwarf-version` stabilization report
## What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?
No RFC/MCP, this flag was added in https://github.com/rust-lang/rust/pull/98350 and was not deemed large enough to require additional process.
The tracking issue for this feature is #103057.
## What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.
None that has been extensively debated but there are a few questions that could have been chosen differently:
1. What should the flag name be?
The current flag name is very specific to DWARF. Other debuginfo formats exist (msvc's CodeView format or https://en.wikipedia.org/wiki/Stabs) so we could have chosen to generalize the flag name (`-{C,Z} debuginfo-version=dwarf-5` for example). While this would extend cleanly to support formats other than DWARF, there are some downsides to this design. Neither CodeView nor Stabs have specification or format versions so it's not clear what values would be supported beyond `dwarf-{2,3,4,5}` or `codeview`. We would also need to take care to ensure the name does not lead users to think they can pick a format other than one supported by the target. For instance, what would `--target x86_64-pc-windows-msvc -Cdebuginfo-version=dwarf-5` do?
2. What is the behavior when flag is used on targets that do not support DWARF?
Currently, passing `-{C,Z} dwarf-version` on targets like `*-windows-msvc` does not do anything. It may be preferable to emit a warning alerting the user that the flag has no effect on the target platform. Alternatively, we could emit an error but this could be annoying since it would require the use of target specific RUSTFLAGS to use the flag correctly (and there isn't a way to target "any platform that uses DWARF" using cfgs).
3. Does the precompiled standard library potentially using a different version of DWARF a problem?
I don't believe this is an issue as debuggers (and other such tools) already must deal with the possibility that an application uses different DWARF versions across its statically or dynamically linked libraries.
## Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those.
No extensions per se, although future DWARF versions could be considered as such. At present, we validate the requested DWARF version is between 2 and 5 (inclusive) so new DWARF versions will not automatically be supported until the validation logic is adjusted.
## Summarize the major parts of the implementation and provide links into the code (or to PRs)
- Targets define their preferred or default DWARF version: 34a5ea911c/compiler/rustc_target/src/spec/mod.rs (L2369)
- We use the target default but this can be overriden by `-{C,Z} dwarf-version` 34a5ea911c/compiler/rustc_session/src/session.rs (L738)
- The flag is validated 34a5ea911c/compiler/rustc_session/src/session.rs (L1253-L1258)
- When debuginfo is generated, we tell LLVM to use the requested value or the target default 34a5ea911c/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs (L106)
## Summarize existing test coverage of this feature
- Test that we actually generate the appropriate DWARF version
- https://github.com/rust-lang/rust/blob/master/tests/assembly/dwarf5.rs
- https://github.com/rust-lang/rust/blob/master/tests/assembly/dwarf4.rs
- Test that LTO with different DWARF versions picks the highest version
- https://github.com/rust-lang/rust/blob/master/tests/assembly/dwarf-mixed-versions-lto.rs
- Test DWARF versions 2-5 are valid while 0, 1 and 6 report an error
- https://github.com/rust-lang/rust/blob/master/tests/ui/debuginfo/dwarf-versions.rs
- Ensure LLVM does not report a warning when LTO'ing different DWARF versions together
- https://github.com/rust-lang/rust/blob/master/tests/ui/lto/dwarf-mixed-versions-lto.rs
## Has a call-for-testing period been conducted? If so, what feedback was received?
No call-for-testing has been conducted but Rust for Linux has been using this flag without issue.
## What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?
All reported bugs have been resolved.
## Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
- Initial implementation in https://github.com/rust-lang/rust/pull/98350 by `@pcwalton`
- Stop emitting `.debug_pubnames` and `.debug_pubtypes` when using DWARF 5 in https://github.com/rust-lang/rust/pull/117962 by `@weihanglo.`
- Refactoring & cleanups (#135739), fix LLVM warning on LTO with different DWARF versions (#136659) and argument validation (#136746) by `@wesleywiser`
## What FIXMEs are still in the code for that feature and why is it ok to leave them there?
No FIXMEs related to this feature.
## What static checks are done that are needed to prevent undefined behavior?
This feature cannot cause undefined behavior.
We ensure the DWARF version is one of the supported values [here](34a5ea911c/compiler/rustc_session/src/session.rs (L1255-L1257)).
## In what way does this feature interact with the reference/specification, and are those edits prepared?
No changes to reference/spec, unstable rustc docs are moved to the stable book as part of the stabilization PR.
## Does this feature introduce new expressions and can they produce temporaries? What are the lifetimes of those temporaries?
No.
## What other unstable features may be exposed by this feature?
`-Zembed-source` requires use of DWARF 5 extensions but has its own feature gate.
## What is tooling support like for this feature, w.r.t rustdoc, clippy, rust-analzyer, rustfmt, etc.?
No support needed for rustdoc, clippy, rust-analyzer, rustfmt or rustup.
Cargo could expose this as an option in build profiles but I would expect the decision as to what version should be used would be made for the entire crate graph at build time rather than by individual package authors.
cc-rs has support for detecting the presence of `-{C,Z} dwarf-version` in `RUSTFLAGS` and providing the corresponding flag to Clang/gcc (https://github.com/rust-lang/cc-rs/pull/1395).
---
Closes#103057
`librustdoc`: more `impl fmt::Display`
Continuation of #137425 and #136828 and #136784
Working towards getting rid of the `write_str` helper
r? `@GuillaumeGomez` (if you want!)
Overhaul `AssocItem`
`AssocItem` has multiple fields that only make sense some of the time. E.g. the `name` can be empty if it's an RPITIT associated type. It's clearer and less error prone if these fields are moved to the relevant `kind` variants.
r? ``@fee1-dead``
compiletest: Add an experimental new executor to replace libtest
This PR adds a new "executor" to compiletest for running the list of collected tests, to eventually replace the current dependency on unstable libtest internals.
The new executor is currently inactive by default. It must be activated explicitly by passing `-n` or `--new-executor` to compiletest, e.g. `./x test ui -- -n`.
(After some amount of wider manual testing, the new executor will hopefully be made the default, and the libtest dependency can be removed. Contributors should not notice any change.)
The new executor is a stripped-down rewrite of the subset of libtest needed by compiletest.
# Supported functionality
- Specifying the number of concurrent tests with `RUST_TEST_THREADS`
- Filtering and skipping tests by name (substring or exact-match)
- Forcibly running ignored tests with `--ignored`
- Optional fail-fast with `--fail-fast`
- JSON output, compatible with bootstrap's parser for libtest output
- Running each test in its own thread
- Short backtraces that ignore the executor itself
- Slow test detection, with a hard-coded timeout of 60 seconds
- Capturing stdout/stderr, via `#![feature(internal_output_capture)]`
- Suppressing output capture with `--no-capture`
# Unsupported functionality
- Non-JSON output, as this is handled by bootstrap instead
- Separate code path for concurrency=1, as the concurrent path should handle this case naturally
- Fallback to running tests synchronously if new threads can't be spawned
- Special handling of hosts that don't support basic functionality like threads or timers
- Our ability to test *targets* should be unaffected
- Graceful handling of some edge cases that could occur in arbitrary user-written unit tests, but would represent bugs in compiletest
- Due to the current need for output capture, the new executor is still not entirely written in stable Rust
---
r? jieyouxu
To accurately reflect that RPITIT assoc items don't have a name. This
avoids the use of `kw::Empty` to mean "no name", which is error prone.
Helps with #137978.
use `realpath` in `bootstrap.py` when creating build-dir
Fixes#139800
r? `@jieyouxu`
My use case for `./build` being a symlink is this: my "default" ~~partition~~ btrfs subvolume is snapshotted/backed up. I don't want to backup target-likes, so I move them to a special subvolume which isn't backed up. `./build` is a symlink into that subvolume. (`build.build-dir` configuration is not fully sufficient, it is still nice to be able to check build files with `ls ./build` or call tools from there)
Rollup of 9 pull requests
Successful merges:
- #138336 (Improve `-Z crate-attr` diagnostics)
- #139636 (Encode dep node edge count as u32 instead of usize)
- #139666 (cleanup `mir_borrowck`)
- #139695 (compiletest: consistently use `camino::{Utf8Path,Utf8PathBuf}` throughout)
- #139699 (Proactively update coroutine drop shim's phase to account for later passes applied during shim query)
- #139718 (enforce unsafe attributes in pre-2024 editions by default)
- #139722 (Move some things to rustc_type_ir)
- #139760 (UI tests: migrate remaining compile time `error-pattern`s to line annotations when possible)
- #139776 (Switch attrs to `diagnostic::on_unimplemented`)
r? `@ghost`
`@rustbot` modify labels: rollup
`hir::AssocItem` currently has a boolean `fn_has_self_parameter` field,
which is misplaced, because it's only relevant for associated fns, not
for associated consts or types. This commit moves it (and renames it) to
the `AssocKind::Fn` variant, where it belongs.
This requires introducing a new C-style enum, `AssocTag`, which is like
`AssocKind` but without the fields. This is because `AssocKind` values
are passed to various functions like `find_by_ident_and_kind` to
indicate what kind of associated item should be searched for, and having
to specify `has_self` isn't relevant there.
New methods:
- Predicates `AssocItem::is_fn` and `AssocItem::is_method`.
- `AssocItem::as_tag` which converts `AssocItem::kind` to `AssocTag`.
Removed `find_by_name_and_kinds`, which is unused.
`AssocItem::descr` can now distinguish between methods and associated
functions, which slightly improves some error messages.
End all lines in src/stage0 with trailing newline
Most tools that process text files prefer if every line ends in \n. Text files without the last newline are aberrant and usually not what you want.
**Before:**
```console
$ cat src/stage0 src/stage0
dist_server=https://static.rust-lang.org
artifacts_server=https://ci-artifacts.rust-lang.org/rustc-builds
...
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.gz=986f6c594d37bcbd3833e053640ba8775f68d26a65c5618386654ef55d7b3542
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.xz=c0d9a88c30d2ab38ec3a11fabb5515ed9bc3ac1a8e35a438d68bf7ff82f6b843dist_server=https://static.rust-lang.org
artifacts_server=https://ci-artifacts.rust-lang.org/rustc-builds
...
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.gz=986f6c594d37bcbd3833e053640ba8775f68d26a65c5618386654ef55d7b3542
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.xz=c0d9a88c30d2ab38ec3a11fabb5515ed9bc3ac1a8e35a438d68bf7ff82f6b843$ ▌
```
**After:**
```console
$ cat src/stage0 src/stage0
dist_server=https://static.rust-lang.org
artifacts_server=https://ci-artifacts.rust-lang.org/rustc-builds
...
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.gz=986f6c594d37bcbd3833e053640ba8775f68d26a65c5618386654ef55d7b3542
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.xz=c0d9a88c30d2ab38ec3a11fabb5515ed9bc3ac1a8e35a438d68bf7ff82f6b843
dist_server=https://static.rust-lang.org
artifacts_server=https://ci-artifacts.rust-lang.org/rustc-builds
...
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.gz=986f6c594d37bcbd3833e053640ba8775f68d26a65c5618386654ef55d7b3542
dist/2025-04-02/rustc-nightly-x86_64-unknown-netbsd.tar.xz=c0d9a88c30d2ab38ec3a11fabb5515ed9bc3ac1a8e35a438d68bf7ff82f6b843
$ ▌
```
compiletest: Make `SUGGESTION` annotations viral
If one of them is expected in a test file, then others should be annotated as well, in the same way as with `HELP`s and `NOTE`s.
This doesn't require much of an additional annotation burden, but simplifies the rules.
r? ```@jieyouxu```
update ```miniz_oxide``` to 0.8.8
I would normally let the auto actions handle this but it turns out 0.8.7 can trigger a panic when debug assertions are enabled in a few cases so I feel it's important it gets sorted more quickly. (and I would ideally like to yank that version but was worried that could cause some issues had been pulled in as a dependency by this repo already before I discovered the problem)
As it can only happen when debug assertions are enabled (the overflow results in the intended result so it doesn't cause any issue in release mode) and using the wrapping buffer mode when decompressing it is very unlikely to cause any issues here but I would like to get it sorted just to be safe. ```miniz_oxide``` is used in the standard library (and some tools) via ```backtrace-rs ``` which doesn't use a wrapping buffer, and thus won't trigger this condition. There does however seem like there are some tools that do dependency on ```flate2``` which does use ```miniz_oxide``` decompression using a a wrapping buffer and could in theory trigger it if they are run when compiled with debug assertions enabled.
It's kinda unclear what version what tool uses though as several of them specify older versions of flate2 which depended on ```miniz_oxide``` 0.7.x in cargo.toml, and ```miniz_oxide```, and not all have a cargo.lock and due to an older version of ```backtrace``` being in the root Cargo.lock which still depended on ```miniz_oxide``` 0.7.4, so that version is also pulled in alongside the newer version.
Rollup of 6 pull requests
Successful merges:
- #139107 (std: make `cmath` functions safe)
- #139607 (Add regression test for #127424)
- #139691 (Document that `opt-dist` requires metrics to be enabled)
- #139707 (Fix comment in bootstrap)
- #139708 (Fix name of field in doc comment)
- #139709 (bootstrap: fix typo in doc string)
r? `@ghost`
`@rustbot` modify labels: rollup
Update windows-bindgen to 0.61.0
This updates the automatically generate Windows API bindings. Not much changed this time:
- There's now `Default` implementations for many types, which is convenient. It does however conflict with one place where we implemented a non-zeroed default (to set the length field). But that's no big problem.
- The `--no-core` flag has been renamed to `--no-deps` to more accurately reflect its meaning (i.e. generate all necessary code without requiring additional dependencies).
- The `--link` flag allows us to set the location of the `link!` macro. Currently we use our workspace's `windows_targets` crate but we could move it into library/std using `--link`. However, this would need to be co-ordinated with the `backtrace` crate (which is a separate crate but included in std using `#[path]`). So I've left that for another time.
Switch `time` to `jiff` for time formatting in ICE dumps
Due to https://github.com/jhpratt/deranged/issues/21, Clippy, R-A and Miri currently fail to build if we bump to 0.4.1, pulled in via `time`. ~~Add some specific type annotations so we don't have to just pin it.~~
~~I can open 3 PRs to the tool repos if preferred, but I thought it might be easier to do this than to pin the transitive dep and go back and remove it once the changes are synced back.~~
run-make-support: Calculate artifact names for target platform, not host platform
This was implemented incorrectly during the porting process, where we relied on std consts. However, `run-make-support` is a host-only library, which meant that these artifact names were for the *host* and not the *target*.
Helps with #138066.
r? `@Kobzol`
try-job: armhf-gnu
try-job: test-various
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: x86_64-mingw-1
try-job: aarch64-apple
try-job: x86_64-apple-1
This was implemented incorrectly during the porting process, where we
relied on std consts. However, `run-make-support` is a host-only
library, which meant that these artifact names were for the *host* and
not the *target*.
