Support for force-warns
Implements https://github.com/rust-lang/rust/issues/85512.
This PR adds a new command line option `force-warns` which will force the provided lints to warn even if they are allowed by some other mechanism such as `#![allow(warnings)]`.
Some remaining issues:
* https://github.com/rust-lang/rust/issues/85512 mentions that `force-warns` should also be capable of taking lint groups instead of individual lints. This is not implemented.
* If a lint has a higher warning level than `warn`, this will cause that lint to warn instead. We probably want to allow the lint to error if it is set to a higher lint and is not allowed somewhere else.
* One test is currently ignored because it's not working - when a deny-by-default lint is allowed, it does not currently warn under `force-warns`. I'm not sure why, but I wanted to get this in before the weekend.
r? `@nikomatsakis`
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`.
Fix handling of `--output-format json` flag
- Don't treat it as deprecated on stable and beta channels. Before, it
would give confusing and incorrect output:
```
warning: the 'output-format' flag is considered deprecated
|
= warning: see issue #44136 <https://github.com/rust-lang/rust/issues/44136> for more information
error: json output format isn't supported for doc generation
```
Both of those are wrong: output-format isn't deprecated, and json
output is supported.
- Require -Z unstable-options for `--output-format json`
Previously, it was allowed by default on nightly, which made it hard
to realize the flag wouldn't be accepted on beta or stable.
To get the test working I had to remove `-Z unstable-options`, which x.py passed to compiletest unconditionally. It was first added in 8c2ec689c1 so `-Z miri` would be allowed. -Z miri is no longer passed unconditionally, so hopefully removing it won't break anything.
r? ```@aDotInTheVoid``` cc ```@HeroicKatora``` ```@CraftSpider```
Thanks to ```@memoryruins``` for pointing it out on Discord!
cc ```@Mark-Simulacrum``` for the change to compiletest.
- Don't treat it as deprecated on stable and beta channels. Before, it
would give confusing and incorrect output:
```
warning: the 'output-format' flag is considered deprecated
|
= warning: see issue #44136 <https://github.com/rust-lang/rust/issues/44136> for more information
error: json output format isn't supported for doc generation
```
Both of those are wrong: output-format isn't deprecated, and json
output is supported.
- Require -Z unstable-options for `--output-format json`
Previously, it was allowed by default on nightly, which made it hard
to realize the flag wouldn't be accepted on beta or stable.
Note that this still allows `--output-format html`, which has been
stable since 1.0.
- Remove unnecessary double-checking of the feature gate when parsing
the output format
- Add custom run-make test since compiletest passes -Zunstable-options
by default
Give a better error when --theme is not a CSS file
Before:
```
error: invalid argument: "bacon.toml"
```
After:
```
error: invalid argument: "bacon.toml"
|
= help: arguments to --theme must be CSS files
```
cc https://github.com/rust-lang/rust/pull/83478
Remove unneeded INITIAL_IDS const
Some IDs inside this map didn't exist anymore, some others were duplicates of what we have inside `IdMap`. So instead of keeping the two around and since `INITIAL_IDS` was only used by `IdMap`, no need to keep both of them.
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```
rustdoc: Add an unstable option to print all unversioned files
This allows sharing those files between different doc invocations
without having to know their names ahead of time.
Helps with https://github.com/rust-lang/docs.rs/issues/1302.
r? ````@GuillaumeGomez```` cc ````@pietroalbini```` ````@Nemo157````
Cleanup rustdoc warnings
## Clean up error reporting for deprecated passes
Using `error!` here goes all the way back to the original commit, https://github.com/rust-lang/rust/pull/8540. I don't see any reason to use logging; rustdoc should use diagnostics wherever possible. See https://github.com/rust-lang/rust/pull/81932#issuecomment-785291244 for further context.
- Use spans for deprecated attributes
- Use a proper diagnostic for unknown passes, instead of error logging
- Add tests for unknown passes
- Improve some wording in diagnostics
## Report that `doc(plugins)` doesn't work using diagnostics instead of `eprintln!`
This also adds a test for the output.
This was added in https://github.com/rust-lang/rust/pull/52194. I don't see any particular reason not to use diagnostics here, I think it was just missed in https://github.com/rust-lang/rust/pull/50541.
- Use spans for deprecated attributes
- Use a proper diagnostic for unknown passes, instead of error logging
- Add tests for unknown passes
- Improve some wording in diagnostics
rustdoc: Remove unnecessary optional
Previously, the HTML output format was represented by both
`Some(OutputFormat::Html)` and `None` so there's no need to have an
optional. Instead, `OutputFormat::Html` is explicitly the default and we
no longer have a "tri-state enum".
r? `````@GuillaumeGomez`````
* Reuse memory
* simplify `next_def_id`, avoid multiple hashing and unnecessary lookups
* remove `all_fake_def_ids`, use the global map instead (probably not a good step toward parallelization, though...)
* convert `add_deref_target` to iterative implementation
* use `ArrayVec` where we know the max number of elements
* minor touchups here and there
* avoid building temporary vectors that get appended to other vectors
At most places I may or may not be doing the compiler's job is this PR.
Previously, the HTML output format was represented by both
`Some(OutputFormat::Html)` and `None` so there's no need to have an
optional. Instead, `OutputFormat::Html` is explicitly the default and we
no longer have a "tri-state enum".
Allow making `RUSTC_BOOTSTRAP` conditional on the crate name
Motivation: This came up in the [Zulip stream](https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/Require.20users.20to.20confirm.20they.20know.20RUSTC_.E2.80.A6.20compiler-team.23350/near/208403962) for https://github.com/rust-lang/compiler-team/issues/350.
See also https://github.com/rust-lang/cargo/pull/6608#issuecomment-458546258; this implements https://github.com/rust-lang/cargo/issues/6627.
The goal is for this to eventually allow prohibiting setting `RUSTC_BOOTSTRAP` in build.rs (https://github.com/rust-lang/cargo/issues/7088).
## User-facing changes
- `RUSTC_BOOTSTRAP=1` still works; there is no current plan to remove this.
- Things like `RUSTC_BOOTSTRAP=0` no longer activate nightly features. In practice this shouldn't be a big deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone uses `RUSTC_BOOTSTRAP=1` anyway.
- `RUSTC_BOOTSTRAP=x` will enable nightly features only for crate `x`.
- `RUSTC_BOOTSTRAP=x,y` will enable nightly features only for crates `x` and `y`.
## Implementation changes
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.
Other major changes:
- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`
I'm not sure whether this counts as T-compiler or T-lang; _technically_ RUSTC_BOOTSTRAP is an implementation detail, but it's been used so much it seems like this counts as a language change too.
r? `@joshtriplett`
cc `@Mark-Simulacrum` `@hsivonen`
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.
Other major changes:
- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`
There is a user-facing change here: things like `RUSTC_BOOTSTRAP=0` no
longer active nightly features. In practice this shouldn't be a big
deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone
uses `RUSTC_BOOTSTRAP=1` anyway.
- Add tests
Check against `Cheat`, not whether nightly features are allowed.
Nightly features are always allowed on the nightly channel.
- Only call `is_nightly_build()` once within a function
- Use booleans consistently for rustc_incremental
Sessions can't be passed through threads, so `read_file` couldn't take a
session. To be consistent, also take a boolean in `write_file_header`.
