From db0ec83ee2ce557a46f0647126bebd7e1eb3f80b Mon Sep 17 00:00:00 2001 From: Scott Schafer Date: Thu, 6 Jun 2024 23:03:53 -0600 Subject: [PATCH] feat: Add an xtask to generate lint documentation --- .cargo/config.toml | 1 + .github/workflows/main.yml | 7 ++ Cargo.lock | 9 +++ crates/xtask-lint-docs/Cargo.toml | 13 +++ crates/xtask-lint-docs/src/main.rs | 122 +++++++++++++++++++++++++++++ src/cargo/util/lints.rs | 2 +- src/doc/src/SUMMARY.md | 1 + src/doc/src/reference/index.md | 1 + src/doc/src/reference/lints.md | 115 +++++++++++++++++++++++++++ 9 files changed, 270 insertions(+), 1 deletion(-) create mode 100644 crates/xtask-lint-docs/Cargo.toml create mode 100644 crates/xtask-lint-docs/src/main.rs create mode 100644 src/doc/src/reference/lints.md diff --git a/.cargo/config.toml b/.cargo/config.toml index c4cd35e56bc9..f1a267084187 100644 --- a/.cargo/config.toml +++ b/.cargo/config.toml @@ -2,6 +2,7 @@ build-man = "run --package xtask-build-man --" stale-label = "run --package xtask-stale-label --" bump-check = "run --package xtask-bump-check --" +lint-docs = "run --package xtask-lint-docs --" [env] # HACK: Until this is stabilized, `snapbox`s polyfill could get confused diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml index e680a32d61fa..de81970f67db 100644 --- a/.github/workflows/main.yml +++ b/.github/workflows/main.yml @@ -83,6 +83,13 @@ jobs: - run: rustup update stable && rustup default stable - run: cargo stale-label + lint-docs: + runs-on: ubuntu-latest + steps: + - uses: actions/checkout@v4 + - run: rustup update stable && rustup default stable + - run: cargo lint-docs --check + # Ensure Cargo.lock is up-to-date lockfile: runs-on: ubuntu-latest diff --git a/Cargo.lock b/Cargo.lock index e2a42023b9c6..41e9a8653256 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -4021,6 +4021,15 @@ dependencies = [ "tracing-subscriber", ] +[[package]] +name = "xtask-lint-docs" +version = "0.1.0" +dependencies = [ + "anyhow", + "cargo", + "clap", +] + [[package]] name = "xtask-stale-label" version = "0.0.0" diff --git a/crates/xtask-lint-docs/Cargo.toml b/crates/xtask-lint-docs/Cargo.toml new file mode 100644 index 000000000000..66bf5c1eda08 --- /dev/null +++ b/crates/xtask-lint-docs/Cargo.toml @@ -0,0 +1,13 @@ +[package] +name = "xtask-lint-docs" +version = "0.1.0" +edition.workspace = true +publish = false + +[dependencies] +anyhow.workspace = true +cargo.workspace = true +clap.workspace = true + +[lints] +workspace = true diff --git a/crates/xtask-lint-docs/src/main.rs b/crates/xtask-lint-docs/src/main.rs new file mode 100644 index 000000000000..b9ca5d9ccb4f --- /dev/null +++ b/crates/xtask-lint-docs/src/main.rs @@ -0,0 +1,122 @@ +use cargo::util::command_prelude::{flag, ArgMatchesExt}; +use cargo::util::lints::{Lint, LintLevel}; +use std::fmt::Write; +use std::path::PathBuf; + +struct LintSection { + level: LintLevel, + names: Vec<&'static str>, + docs: String, +} + +impl LintSection { + fn new(level: LintLevel) -> Self { + Self { + level, + names: Vec::new(), + docs: String::new(), + } + } + + fn add_lint(&mut self, lint: &Lint) { + self.names.push(lint.name); + + // We want to add an extra `#` to each heading as it may be unexpected that + // each lint is a subheading of the lint level. + // We only want to do this for headings that are at least `##` as `#` is + // used for comments and links. + let docs = lint.docs.replace("## ", "### "); + + self.docs.push_str("### `"); + self.docs.push_str(lint.name); + self.docs.push_str("`\n"); + self.docs.push_str(&docs); + self.docs.push_str("\n"); + } + + fn write(&self, buf: &mut String) -> std::fmt::Result { + let title = match self.level { + LintLevel::Allow => "Allowed-by-default", + LintLevel::Warn => "Warn-by-default", + LintLevel::Deny => "Deny-by-default", + LintLevel::Forbid => "Forbid-by-default", + }; + writeln!(buf, "## {title}\n")?; + writeln!( + buf, + "These lints are all set to the '{}' level by default.", + self.level + )?; + for name in &self.names { + writeln!(buf, "- [`{}`](#{})", name, name)?; + } + writeln!(buf, "\n{}", self.docs) + } +} + +fn cli() -> clap::Command { + clap::Command::new("xtask-lint-docs").arg(flag("check", "Check that the docs are up-to-date")) +} + +fn main() -> anyhow::Result<()> { + let args = cli().get_matches(); + let check = args.flag("check"); + + let mut allow = LintSection::new(LintLevel::Allow); + let mut warn = LintSection::new(LintLevel::Warn); + let mut deny = LintSection::new(LintLevel::Deny); + let mut forbid = LintSection::new(LintLevel::Forbid); + for lint in cargo::util::lints::LINTS { + if !lint.docs.contains(&"DO NOT DOCUMENT") { + let sectipn = match lint.default_level { + LintLevel::Allow => &mut allow, + LintLevel::Warn => &mut warn, + LintLevel::Deny => &mut deny, + LintLevel::Forbid => &mut forbid, + }; + sectipn.add_lint(lint); + } + } + + let mut buf = String::new(); + writeln!(buf, "# Lints\n")?; + writeln!( + buf, + "Note: [Cargo's linting system is unstable](unstable.md#lintscargo) and can only be used on nightly toolchains" + )?; + + if !allow.names.is_empty() { + allow.write(&mut buf)?; + } + if !warn.names.is_empty() { + warn.write(&mut buf)?; + } + if !deny.names.is_empty() { + deny.write(&mut buf)?; + } + if !forbid.names.is_empty() { + forbid.write(&mut buf)?; + } + + if check { + let old = std::fs::read_to_string(lint_docs_path())?; + if old != buf { + anyhow::bail!( + "The lints documentation is out-of-date. Run `cargo lint-docs` to update it." + ); + } + } else { + std::fs::write(lint_docs_path(), buf)?; + } + Ok(()) +} + +fn lint_docs_path() -> PathBuf { + let pkg_root = env!("CARGO_MANIFEST_DIR"); + let ws_root = PathBuf::from(format!("{pkg_root}/../..")); + let path = { + let path = ws_root.join("src/doc/src/reference/lints.md"); + path.canonicalize().unwrap_or(path) + }; + path +} diff --git a/src/cargo/util/lints.rs b/src/cargo/util/lints.rs index db7d6cca6198..a3a76e35a1ee 100644 --- a/src/cargo/util/lints.rs +++ b/src/cargo/util/lints.rs @@ -13,7 +13,7 @@ use std::path::Path; use toml_edit::ImDocument; const LINT_GROUPS: &[LintGroup] = &[TEST_DUMMY_UNSTABLE]; -const LINTS: &[Lint] = &[ +pub const LINTS: &[Lint] = &[ IM_A_TEAPOT, IMPLICIT_FEATURES, UNKNOWN_LINTS, diff --git a/src/doc/src/SUMMARY.md b/src/doc/src/SUMMARY.md index 9ebd7915bb9c..b18e69111e51 100644 --- a/src/doc/src/SUMMARY.md +++ b/src/doc/src/SUMMARY.md @@ -45,6 +45,7 @@ * [SemVer Compatibility](reference/semver.md) * [Future incompat report](reference/future-incompat-report.md) * [Reporting build timings](reference/timings.md) + * [Lints](reference/lints.md) * [Unstable Features](reference/unstable.md) * [Cargo Commands](commands/index.md) diff --git a/src/doc/src/reference/index.md b/src/doc/src/reference/index.md index afff4fa89a4b..d20efb8c2ba0 100644 --- a/src/doc/src/reference/index.md +++ b/src/doc/src/reference/index.md @@ -23,4 +23,5 @@ The reference covers the details of various areas of Cargo. * [SemVer Compatibility](semver.md) * [Future incompat report](future-incompat-report.md) * [Reporting build timings](timings.md) +* [Lints](lints.md) * [Unstable Features](unstable.md) diff --git a/src/doc/src/reference/lints.md b/src/doc/src/reference/lints.md new file mode 100644 index 000000000000..f7908b8f1e99 --- /dev/null +++ b/src/doc/src/reference/lints.md @@ -0,0 +1,115 @@ +# Lints + +Note: [Cargo's linting system is unstable](unstable.md#lintscargo) and can only be used on nightly toolchains +## Allowed-by-default + +These lints are all set to the 'allow' level by default. +- [`implicit_features`](#implicit_features) + +### `implicit_features` + +Note: This only runs on edition 2021 and below + +#### What it does +Checks for implicit features for optional dependencies + +#### Why it is bad +By default, cargo will treat any optional dependency as a [feature]. As of +cargo 1.60, these can be disabled by declaring a feature that activates the +optional dependency as `dep:` (see [RFC #3143]). + +In the 2024 edition, `cargo` will stop exposing optional dependencies as +features implicitly, requiring users to add `foo = ["dep:foo"]` if they +still want it exposed. + +For more information, see [RFC #3491] + +#### Example +```toml +edition = "2021" + +[dependencies] +bar = { version = "0.1.0", optional = true } + +[features] +# No explicit feature activation for `bar` +``` + +Instead, the dependency should have an explicit feature: +```toml +edition = "2021" + +[dependencies] +bar = { version = "0.1.0", optional = true } + +[features] +bar = ["dep:bar"] +``` + +[feature]: https://doc.rust-lang.org/cargo/reference/features.html +[RFC #3143]: https://rust-lang.github.io/rfcs/3143-cargo-weak-namespaced-features.html +[RFC #3491]: https://rust-lang.github.io/rfcs/3491-remove-implicit-features.html + + +## Warn-by-default + +These lints are all set to the 'warn' level by default. +- [`unknown_lints`](#unknown_lints) +- [`unused_optional_dependency`](#unused_optional_dependency) + +### `unknown_lints` + +#### What it does +Checks for unknown lints in the `[lints.cargo]` table + +#### Why it is bad +- The lint name could be misspelled, leading to confusion as to why it is + not working as expected +- The unknown lint could end up causing an error if `cargo` decides to make + a lint with the same name in the future + +#### Example +```toml +[lints.cargo] +this-lint-does-not-exist = "warn" +``` + +### `unused_optional_dependency` + +Note: This only runs on edition 2024+ + +#### What it does +Checks for optional dependencies that are not activated by any feature + +#### Why it is bad +Starting in the 2024 edition, `cargo` no longer implicitly creates features +for optional dependencies (see [RFC #3491]). This means that any optional +dependency not specified with `"dep:"` in some feature is now unused. +This change may be surprising to users who have been using the implicit +features `cargo` has been creating for optional dependencies. + +#### Example +```toml +edition = "2024" + +[dependencies] +bar = { version = "0.1.0", optional = true } + +[features] +# No explicit feature activation for `bar` +``` + +Instead, the dependency should be removed or activated in a feature: +```toml +edition = "2024" + +[dependencies] +bar = { version = "0.1.0", optional = true } + +[features] +bar = ["dep:bar"] +``` + +[RFC #3491]: https://rust-lang.github.io/rfcs/3491-remove-implicit-features.html + +