Remove implicit names and values from `--cfg` in `--check-cfg`
This PR remove the implicit names and values from `--cfg` in `--check-cfg` because the behavior is quite surprising but also because it's really easy to inadvertently really on the implicitness and when the `--cfg` is not set anymore to have an unexpected warning from an unexpected condition that pass with the implicitness.
This change in behavior will also enable us to warn when an unexpected `--cfg` is passed, ex: the user wrote `--cfg=unstabl` instead of `--cfg=unstable`. The implementation of the warning will be done in a follow-up PR.
cc `@petrochenkov`
proc_macro: use crossbeam channels for the proc_macro cross-thread bridge
This is done by having the crossbeam dependency inserted into the `proc_macro` server code from the server side, to avoid adding a dependency to `proc_macro`.
In addition, this introduces a -Z command-line option which will switch rustc to run proc-macros using this cross-thread executor. With the changes to the bridge in #98186, #98187, #98188 and #98189, the performance of the executor should be much closer to same-thread execution.
In local testing, the crossbeam executor was substantially more performant than either of the two existing `CrossThread` strategies, so they have been removed to keep things simple.
r? `@eddyb`
This is done by having the crossbeam dependency inserted into the
proc_macro server code from the server side, to avoid adding a
dependency to proc_macro.
In addition, this introduces a -Z command-line option which will switch
rustc to run proc-macros using this cross-thread executor. With the
changes to the bridge in #98186, #98187, #98188 and #98189, the
performance of the executor should be much closer to same-thread
execution.
In local testing, the crossbeam executor was substantially more
performant than either of the two existing CrossThread strategies, so
they have been removed to keep things simple.
Some command-line options accessible through `sess.opts` are best
accessed through wrapper functions on `Session`, `TyCtxt` or otherwise,
rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed
through a wrapper function so that this is prohibited. Options are
annotated with a new attribute `rustc_lint_opt_deny_field_access` which
can specify the error message (i.e. "use this other function instead")
to be emitted.
A simpler alternative would be to simply rename the options in the
option type so that it is clear they should not be used, however this
doesn't prevent uses, just discourages them. Another alternative would
be to make the option fields private, and adding accessor functions on
the option types, however the wrapper functions sometimes rely on
additional state from `Session` or `TyCtxt` which wouldn't be available
in an function on the option type, so the accessor would simply make the
field available and its use would be discouraged too.
Signed-off-by: David Wood <david.wood@huawei.com>
Rename the `--output-width` flag to `--diagnostic-width` as this appears
to be the preferred name within the compiler team.
Signed-off-by: David Wood <david.wood@huawei.com>
Rename the `--terminal-width` flag to `--output-width` as the behaviour
doesn't just apply to terminals (and so is slightly less accurate).
Signed-off-by: David Wood <david.wood@huawei.com>
Formerly `-Zterminal-width`, `--terminal-width` allows the user or build
tool to inform rustc of the width of the terminal so that diagnostics
can be truncated.
Signed-off-by: David Wood <david.wood@huawei.com>
Make sure `-Dunused-crate-dependencies --json unused-externs` makes rustc exit with error status
This PR:
- fixes compiletest to understand unused extern notifications
- adds tests for `--json unused-externs`
- makes sure that deny-level unused externs notifications are treated as compile errors
- refactors the `emit_unused_externs` callstack to plumb through the level as an enum as a string, and adds `Level::is_error`
Update: adds `--json unused-externs-silent` with the original behaviour since Cargo needs it. Should address `@est31's` concerns.
Fixes: https://github.com/rust-lang/rust/issues/96068
Add missing `target_feature` to the list of well known cfg names
This PR adds the missing `target_feature` cfg name to the list of well known cfg names.
It was notice missing in https://github.com/rust-lang/rust/issues/96472 thanks to `@bjorn3,` the reason being that `--check-cfg=names()` automatically inherit the names passed by `--cfg` (or internal to `rustc`) and is seems that the vast majority of targets have at least one target feature leading to `target_feature` being a well known name in most target but it should always be a well known name so this PR add it unconditionally to list.
r? `@petrochenkov`
Since Cargo wants to do its own fatal error handling for unused
dependencies, add the option `--json unused-externs-silent` which
has the original behaviour of not indicating non-zero exit status for
`deny`/`forbid`-level unused dependencies.
This adds `nounused` to the set of extern flags:
`--extern nounused:core=/path/to/core/libcore.rlib`.
The effect of this flag is to suppress `unused-crate-dependencies`
warnings relating to the crate.
`--extern-location` was an experiment to investigate the best way to
generate useful diagnostics for unused dependency warnings by enabling a
build system to identify the corresponding build config.
While I did successfully use this, I've since been convinced the
alternative `--json unused-externs` mechanism is the way to go, and
there's no point in having two mechanisms with basically the same
functionality.
This effectively reverts https://github.com/rust-lang/rust/pull/72603
Extend loading of Fluent bundles so that bundles can be loaded from the
sysroot based on the language requested by the user, or using a nightly
flag.
Sysroot bundles are loaded from `$sysroot/share/locale/$locale/*.ftl`.
Signed-off-by: David Wood <david.wood@huawei.com>
Implement -Z oom=panic
This PR removes the `#[rustc_allocator_nounwind]` attribute on `alloc_error_handler` which allows it to unwind with a panic instead of always aborting. This is then used to implement `-Z oom=panic` as per RFC 2116 (tracking issue #43596).
Perf and binary size tests show negligible impact.
Add well known values to `--check-cfg` implementation
This pull-request adds well known values for the well known names via `--check-cfg=values()`.
[RFC 3013: Checking conditional compilation at compile time](https://rust-lang.github.io/rfcs/3013-conditional-compilation-checking.html#checking-conditional-compilation-at-compile-time) doesn't define this at all, but this seems a nice improvement.
The activation is done by a empty `values()` (new syntax) similar to `names()` except that `names(foo)` also activate well known names while `values(aa, "aa", "kk")` would not.
As stated this use a different activation logic because well known values for the well known names are not always sufficient.
In fact this is problematic for every `target_*` cfg because of non builtin targets, as the current implementation use those built-ins targets to create the list the well known values.
The implementation is straight forward, first we gather (if necessary) all the values (lazily or not) and then we apply them.
r? ```@petrochenkov```
This change adds a flag for configuring control-flow protection in the
LLVM backend. In Clang, this flag is exposed as `-fcf-protection` with
options `none|branch|return|full`. This convention is followed for
`rustc`, though as a codegen option: `rustc -Z
cf-protection=<none|branch|return|full>`.
Co-authored-by: BlackHoleFox <blackholefoxdev@gmail.com>
This option introduced in #15820 allows a custom crate to be imported in
the place of std, but with the name std. I don't think there is any
value to this. At most it is confusing users of a driver that uses this option. There are no users of
this option on github. If anyone still needs it, they can emulate it
injecting #![no_core] in addition to their own prelude.
Stabilize `-Z instrument-coverage` as `-C instrument-coverage`
(Tracking issue for `instrument-coverage`: https://github.com/rust-lang/rust/issues/79121)
This PR stabilizes support for instrumentation-based code coverage, previously provided via the `-Z instrument-coverage` option. (Continue supporting `-Z instrument-coverage` for compatibility for now, but show a deprecation warning for it.)
Many, many people have tested this support, and there are numerous reports of it working as expected.
Move the documentation from the unstable book to stable rustc documentation. Update uses and documentation to use the `-C` option.
Addressing questions raised in the tracking issue:
> If/when stabilized, will the compiler flag be updated to -C instrument-coverage? (If so, the -Z variant could also be supported for some time, to ease migrations for existing users and scripts.)
This stabilization PR updates the option to `-C` and keeps the `-Z` variant to ease migration.
> The Rust coverage implementation depends on (and automatically turns on) -Z symbol-mangling-version=v0. Will stabilizing this feature depend on stabilizing v0 symbol-mangling first? If so, what is the current status and timeline?
This stabilization PR depends on https://github.com/rust-lang/rust/pull/90128 , which stabilizes `-C symbol-mangling-version=v0` (but does not change the default symbol-mangling-version).
> The Rust coverage implementation implements the latest version of LLVM's Coverage Mapping Format (version 4), which forces a dependency on LLVM 11 or later. A compiler error is generated if attempting to compile with coverage, and using an older version of LLVM.
Given that LLVM 13 has now been released, requiring LLVM 11 for coverage support seems like a reasonable requirement. If people don't have at least LLVM 11, nothing else breaks; they just can't use coverage support. Given that coverage support currently requires a nightly compiler and LLVM 11 or newer, allowing it on a stable compiler built with LLVM 11 or newer seems like an improvement.
The [tracking issue](https://github.com/rust-lang/rust/issues/79121) and the [issue label A-code-coverage](https://github.com/rust-lang/rust/labels/A-code-coverage) link to a few open issues related to `instrument-coverage`, but none of them seem like showstoppers. All of them seem like improvements and refinements we can make after stabilization.
The original `-Z instrument-coverage` support went through a compiler-team MCP at https://github.com/rust-lang/compiler-team/issues/278 . Based on that, `@pnkfelix` suggested that this needed a stabilization PR and a compiler-team FCP.
