Rollup of 4 pull requests
Successful merges:
- #93850 (Don't ICE when an extern static is too big for the current architecture)
- #94154 (Wire up unstable rustc --check-cfg to rustdoc)
- #94353 (Fix debug_assert in unused lint pass)
- #94366 (Add missing item to release notes)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
rustc_errors: let `DiagnosticBuilder::emit` return a "guarantee of emission".
That is, `DiagnosticBuilder` is now generic over the return type of `.emit()`, so we'll now have:
* `DiagnosticBuilder<ErrorReported>` for error (incl. fatal/bug) diagnostics
* can only be created via a `const L: Level`-generic constructor, that limits allowed variants via a `where` clause, so not even `rustc_errors` can accidentally bypass this limitation
* asserts `diagnostic.is_error()` on emission, just in case the construction restriction was bypassed (e.g. by replacing the whole `Diagnostic` inside `DiagnosticBuilder`)
* `.emit()` returns `ErrorReported`, as a "proof" token that `.emit()` was called
(though note that this isn't a real guarantee until after completing the work on
#69426)
* `DiagnosticBuilder<()>` for everything else (warnings, notes, etc.)
* can also be obtained from other `DiagnosticBuilder`s by calling `.forget_guarantee()`
This PR is a companion to other ongoing work, namely:
* #69426
and it's ongoing implementation:
#93222
the API changes in this PR are needed to get statically-checked "only errors produce `ErrorReported` from `.emit()`", but doesn't itself provide any really strong guarantees without those other `ErrorReported` changes
* #93244
would make the choices of API changes (esp. naming) in this PR fit better overall
In order to be able to let `.emit()` return anything trustable, several changes had to be made:
* `Diagnostic`'s `level` field is now private to `rustc_errors`, to disallow arbitrary "downgrade"s from "some kind of error" to "warning" (or anything else that doesn't cause compilation to fail)
* it's still possible to replace the whole `Diagnostic` inside the `DiagnosticBuilder`, sadly, that's harder to fix, but it's unlikely enough that we can paper over it with asserts on `.emit()`
* `.cancel()` now consumes `DiagnosticBuilder`, preventing `.emit()` calls on a cancelled diagnostic
* it's also now done internally, through `DiagnosticBuilder`-private state, instead of having a `Level::Cancelled` variant that can be read (or worse, written) by the user
* this removes a hazard of calling `.cancel()` on an error then continuing to attach details to it, and even expect to be able to `.emit()` it
* warnings were switched to *only* `can_emit_warnings` on emission (instead of pre-cancelling early)
* `struct_dummy` was removed (as it relied on a pre-`Cancelled` `Diagnostic`)
* since `.emit()` doesn't consume the `DiagnosticBuilder` <sub>(I tried and gave up, it's much more work than this PR)</sub>,
we have to make `.emit()` idempotent wrt the guarantees it returns
* thankfully, `err.emit(); err.emit();` can return `ErrorReported` both times, as the second `.emit()` call has no side-effects *only* because the first one did do the appropriate emission
* `&mut Diagnostic` is now used in a lot of function signatures, which used to take `&mut DiagnosticBuilder` (in the interest of not having to make those functions generic)
* the APIs were already mostly identical, allowing for low-effort porting to this new setup
* only some of the suggestion methods needed some rework, to have the extra `DiagnosticBuilder` functionality on the `Diagnostic` methods themselves (that change is also present in #93259)
* `.emit()`/`.cancel()` aren't available, but IMO calling them from an "error decorator/annotator" function isn't a good practice, and can lead to strange behavior (from the caller's perspective)
* `.downgrade_to_delayed_bug()` was added, letting you convert any `.is_error()` diagnostic into a `delay_span_bug` one (which works because in both cases the guarantees available are the same)
This PR should ideally be reviewed commit-by-commit, since there is a lot of fallout in each.
r? `@estebank` cc `@Manishearth` `@nikomatsakis` `@mark-i-m`
As an example:
#[test]
#[ignore = "not yet implemented"]
fn test_ignored() {
...
}
Will now render as:
running 2 tests
test tests::test_ignored ... ignored, not yet implemented
test result: ok. 1 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 0.00s
1. It captured stdout and not stderr
2. It isn't used anywhere
3. All error messages should go to the DiagnosticOutput instead
4. It modifies thread local state
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.
Continue supporting -Z instrument-coverage for compatibility for now,
but show a deprecation warning for it.
Update uses and documentation to use the -C option.
Move the documentation from the unstable book to stable rustc
documentation.
This can be replicated in full with other existing features, there's no
need to have a separate option for it.
This also fixes a bug where `--test-args=--show-output` had no effect,
and updates the documentation.
This partially reverts #91026, because rustdoc needs to detect the extern statements,
even when they appear inside implicit `main()`. It does not entirely revert it,
so the old bug is still fixed, by duplicating some of the logic from `parse_mod`
instead of trying to use it directly.
Fixes#91134
The basic problem with this is that rustdoc, when hunting for `fn main`, will stop
parsing after it reaches a fatal error. This unexpected semicolon was a fatal error,
so in `src/test/rustdoc-ui/failed-doctest-extra-semicolon-on-item.rs`, it would wrap
the doctest in an implied main function, turning it into this:
fn main() {
struct S {};
fn main() {
assert_eq!(0, 1);
}
}
This, as it turns out, is totally valid, and it executes no assertions, so *it passes,*
even though the user wanted it to execute the assertion.
The Rust parser already has the ability to recover from these unexpected semicolons,
but to do so, it needs to use the `parse_mod` function, so this commit changes it to do that.
Rustdoc is special as usual and doesn't go through RunCompiler, so it
needs its own explicit checks. The rest of the tools go through
RunCompiler, so they should be fine.
By adding #![doc(cfg_hide(foobar))] to the crate attributes the cfg
#[cfg(foobar)] (and _only_ that _exact_ cfg) will not be implicitly
treated as a doc(cfg) to render a message in the documentation.
This is only active when the `doc_cfg` feature is active.
The implicit cfg can be overridden via #[doc(cfg(...))], so e.g. to
hide a #[cfg] you can use something like:
```rust
#[cfg(unix)]
#[doc(cfg(all()))]
pub struct Unix;
```
(since `all()` is always true, it is never shown in the docs)
Show test type during prints
Test output can sometimes be confusing. For example doctest with the no_run argument are displayed the same way than test that are run.
During #83857 I got the feedback that test output can be confusing.
For the moment test output is
```
test $DIR/test-type.rs - f (line 12) ... ignored
test $DIR/test-type.rs - f (line 15) ... ok
test $DIR/test-type.rs - f (line 21) ... ok
test $DIR/test-type.rs - f (line 6) ... ok
```
I propose to change output by indicating the test type as
```
test $DIR/test-type.rs - f (line 12) ... ignored
test $DIR/test-type.rs - f (line 15) - compile ... ok
test $DIR/test-type.rs - f (line 21) - compile fail ... ok
test $DIR/test-type.rs - f (line 6) ... ok
```
by indicating the test type after the test name (and in the case of doctest after the function name and line) and before the "...".
------------
Note: this is a proof of concept, the implementation is probably not optimal as the properties added in `TestDesc` are only use in the display and does not represent actual change of behavior, maybe `TestType::DocTest` could have fields
Fix `--remap-path-prefix` not correctly remapping `rust-src` component paths and unify handling of path mapping with virtualized paths
This PR fixes#73167 ("Binaries end up containing path to the rust-src component despite `--remap-path-prefix`") by preventing real local filesystem paths from reaching compilation output if the path is supposed to be remapped.
`RealFileName::Named` introduced in #72767 is now renamed as `LocalPath`, because this variant wraps a (most likely) valid local filesystem path.
`RealFileName::Devirtualized` is renamed as `Remapped` to be used for remapped path from a real path via `--remap-path-prefix` argument, as well as real path inferred from a virtualized (during compiler bootstrapping) `/rustc/...` path. The `local_path` field is now an `Option<PathBuf>`, as it will be set to `None` before serialisation, so it never reaches any build output. Attempting to serialise a non-`None` `local_path` will cause an assertion faliure.
When a path is remapped, a `RealFileName::Remapped` variant is created. The original path is preserved in `local_path` field and the remapped path is saved in `virtual_name` field. Previously, the `local_path` is directly modified which goes against its purpose of "suitable for reading from the file system on the local host".
`rustc_span::SourceFile`'s fields `unmapped_path` (introduced by #44940) and `name_was_remapped` (introduced by #41508 when `--remap-path-prefix` feature originally added) are removed, as these two pieces of information can be inferred from the `name` field: if it's anything other than a `FileName::Real(_)`, or if it is a `FileName::Real(RealFileName::LocalPath(_))`, then clearly `name_was_remapped` would've been false and `unmapped_path` would've been `None`. If it is a `FileName::Real(RealFileName::Remapped{local_path, virtual_name})`, then `name_was_remapped` would've been true and `unmapped_path` would've been `Some(local_path)`.
cc `@eddyb` who implemented `/rustc/...` path devirtualisation
Unify rustc and rustdoc parsing of `cfg()`
This extracts a new `parse_cfg` function that's used between both.
- Treat `#[doc(cfg(x), cfg(y))]` the same as `#[doc(cfg(x)]
#[doc(cfg(y))]`. Previously it would be completely ignored.
- Treat `#[doc(inline, cfg(x))]` the same as `#[doc(inline)]
#[doc(cfg(x))]`. Previously, the cfg would be ignored.
- Pass the cfg predicate through to rustc_expand to be validated
Technically this is a breaking change, but doc_cfg is still nightly so I don't think it matters.
Fixes https://github.com/rust-lang/rust/issues/84437.
r? `````````@petrochenkov`````````
This extracts a new `parse_cfg` function that's used between both.
- Treat `#[doc(cfg(x), cfg(y))]` the same as `#[doc(cfg(x)]
#[doc(cfg(y))]`. Previously it would be completely ignored.
- Treat `#[doc(inline, cfg(x))]` the same as `#[doc(inline)]
#[doc(cfg(x))]`. Previously, the cfg would be ignored.
- Pass the cfg predicate through to rustc_expand to be validated
Co-authored-by: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
added --no-run option for rustdoc
resolve#59053
add `--no-run` option for `rustdoc` for compiling doc test but not running them.
Intended for use with `--persist-doctests`.
check item.is_fake() instead of self_id.is_some()
Remove empty branching in Attributes::from_ast
diverse small refacto after Josha review
cfg computation moved in merge_attrs
refacto use from_ast twice for coherence
take cfg out of Attributes and move it to Item
refacto use from_def_id_and_attrs_and_parts instead of an old trick
most of josha suggestions + check if def_id is not fake before using it in a query
Removed usage of Attributes in FnDecl and ExternalCrate. Relocate part of the Attributes fields as functions in AttributesExt.
Add an unstable --json=unused-externs flag to print unused externs
This adds an unstable flag to print a list of the extern names not used by cargo.
This PR will enable cargo to collect unused dependencies from all units and provide warnings.
The companion PR to cargo is: https://github.com/rust-lang/cargo/pull/8437
The goal is eventual stabilization of this flag in rustc as well as in cargo.
Discussion of this feature is mostly contained inside these threads: #57274#72342#72603
The feature builds upon the internal datastructures added by #72342
Externs are uniquely identified by name and the information is sufficient for cargo.
If the mode is enabled, rustc will print json messages like:
```
{"unused_extern_names":["byteorder","openssl","webpki"]}
```
For a crate that got passed byteorder, openssl and webpki dependencies but needed none of them.
### Q: Why not pass -Wunused-crate-dependencies?
A: See [ehuss's comment here](https://github.com/rust-lang/rust/issues/57274#issuecomment-624839355)
TLDR: it's cleaner. Rust's warning system wasn't built to be filtered or edited by cargo.
Even a basic implementation of the feature would have to change the "n warnings emitted" line that rustc prints at the end.
Cargo ideally wants to synthesize its own warnings anyways. For example, it would be hard for rustc to emit warnings like
"dependency foo is only used by dev targets", suggesting to make it a dev-dependency instead.
### Q: Make rustc emit used or unused externs?
A: Emitting used externs has the advantage that it simplifies cargo's collection job.
However, emitting unused externs creates less data to be communicated between rustc and cargo.
Often you want to paste a cargo command obtained from `cargo build -vv` for doing something
completely unrelated. The message is emitted always, even if no warning or error is emitted.
At that point, even this tiny difference in "noise" matters. That's why I went with emitting unused externs.
### Q: One json msg per extern or a collective json msg?
A: Same as above, the data format should be concise. Having 30 lines for the 30 crates a crate uses would be disturbing to readers.
Also it helps the cargo implementation to know that there aren't more unused deps coming.
### Q: Why use names of externs instead of e.g. paths?
A: Names are both sufficient as well as neccessary to uniquely identify a passed `--extern` arg.
Names are sufficient because you *must* pass a name when passing an `--extern` arg.
Passing a path is optional on the other hand so rustc might also figure out a crate's location from the file system.
You can also put multiple paths for the same extern name, via e.g. `--extern hello=/usr/lib/hello.rmeta --extern hello=/usr/local/lib/hello.rmeta`,
but rustc will only ever use one of those paths.
Also, paths don't identify a dependency uniquely as it is possible to have multiple different extern names point to the same path.
So paths are ill-suited for identification.
### Q: What about 2015 edition crates?
A: They are fully supported.
Even on the 2015 edition, an explicit `--extern` flag is is required to enable `extern crate foo;` to work (outside of sysroot crates, which this flag doesn't warn about anyways).
So the lint would still fire on 2015 edition crates if you haven't included a dependency specified in Cargo.toml using `extern crate foo;` or similar.
The lint won't fire if your sole use in the crate is through a `extern crate foo;` statement, but that's not its job.
For detecting unused `extern crate foo` statements, there is the `unused_extern_crates` lint
which can be enabled by `#![warn(unused_extern_crates)]` or similar.
cc ```@jsgf``` ```@ehuss``` ```@petrochenkov``` ```@estebank```
StructField -> FieldDef ("field definition")
Field -> ExprField ("expression field", not "field expression")
FieldPat -> PatField ("pattern field", not "field pattern")
Also rename visiting and other methods working on them.
- Rename `broken_intra_doc_links` to `rustdoc::broken_intra_doc_links`
- Ensure that the old lint names still work and give deprecation errors
- Register lints even when running doctests
Otherwise, all `rustdoc::` lints would be ignored.
- Register all existing lints as removed
This unfortunately doesn't work with `register_renamed` because tool
lints have not yet been registered when rustc is running. For similar
reasons, `check_backwards_compat` doesn't work either. Call
`register_removed` directly instead.
- Fix fallout
+ Rustdoc lints for compiler/
+ Rustdoc lints for library/
Note that this does *not* suggest `rustdoc::broken_intra_doc_links` for
`rustdoc::intra_doc_link_resolution_failure`, since there was no time
when the latter was valid.
Unfortunately, this can't currently be tested. The problem is that we
need the file to be compiled first to then be used as dependency, which
cannot be done currently unfortunately in the rustdoc test suites.
Example:
```rust
// name this file "foo.rs"
/// ```
/// let x = foo::foo();
/// ```
pub fn foo() {}
```
If you run `rustdoc --test foo.rs`, you'll get:
```
running 1 test
test foo.rs - foo (line 1) ... FAILED
failures:
---- foo.rs - foo (line 1) stdout ----
error[E0463]: can't find crate for `foo`
--> foo.rs:0:1
|
2 | extern crate foo;
| ^^^^^^^^^^^^^^^^^ can't find crate
```
If a test were possible, it would look something like
````rust
#![crate_name = "mod"]
#![crate_type = "lib"]
//! ```
//! // NOTE: requires that the literal string 'mod' appears in the doctest for
//! // the bug to appear
//! assert_eq!(1, 1);
//! ```
````
Deny rustc::internal lints for rustdoc and clippy
- Fix rustc::internal lints for rustdoc
- Deny internal lints only for rustdoc and clippy (previously the lints were ignored for clippy because -Zunstable-options didn't get passed)
Fixes#81007
Previously, we would fail to collect tokens in the proper place when
only builtin attributes were present. As a result, we would end up with
attribute tokens in the collected `TokenStream`, leading to duplication
when we attempted to prepend the attributes from the AST node.
We now explicitly track when token collection must be performed due to
nomterminal parsing.
The first parse is to collect whether the code contains macros, has
`main`, and uses other crates. In that pass we ignore errors as those
will be reported when the test file is actually built.
For that we need to reset errors in the `Diagnostic` otherwise when
dropping it unhandled errors will be reported as compiler bugs.
Fixes#80992
This makes it possible to pass the `Impl` directly to functions, instead
of having to pass each of the many fields one at a time. It also
simplifies matches in many cases.
When using the unstable `--persist-doctests` option,
Windows path separators were not escaped properly. Also when running
the command in a workspace, crate files can overwrite each other.
Before: `src\lib_rs_1_0\rust_out`
After: `\crate_a_src_lib_rs_1_0\rust_out`, `\crate_b_src_lib_rs_1_0\rust_out`
