clippy_dev/src/update_lints.rs

use crate::parse::cursor::Cursor;
use crate::parse::{DeprecatedLint, Lint, ParseCx, RenamedLint};
use crate::utils::{FileUpdater, UpdateMode, UpdateStatus, update_text_region_fn};
use itertools::Itertools;
use std::collections::HashSet;
use std::fmt::Write;
use std::path::{self, Path};

const GENERATED_FILE_COMMENT: &str = "// This file was generated by `cargo dev update_lints`.\n\
     // Use that command to update this file and do not edit by hand.\n\
     // Manual edits will be overwritten.\n\n";

const DOCS_LINK: &str = "https://rust-lang.github.io/rust-clippy/master/index.html";

/// Runs the `update_lints` command.
///
/// This updates various generated values from the lint source code.
///
/// `update_mode` indicates if the files should be updated or if updates should be checked for.
///
/// # Panics
///
/// Panics if a file path could not read from or then written to
pub fn update(cx: ParseCx<'_>, update_mode: UpdateMode) {
    let lints = cx.find_lint_decls();
    let (deprecated, renamed) = cx.read_deprecated_lints();
    generate_lint_files(update_mode, &lints, &deprecated, &renamed);
}

#[expect(clippy::too_many_lines)]
pub fn generate_lint_files(
    update_mode: UpdateMode,
    lints: &[Lint<'_>],
    deprecated: &[DeprecatedLint<'_>],
    renamed: &[RenamedLint<'_>],
) {
    let mut updater = FileUpdater::default();
    updater.update_file_checked(
        "cargo dev update_lints",
        update_mode,
        "README.md",
        &mut update_text_region_fn("[There are over ", " lints included in this crate!]", |dst| {
            write!(dst, "{}", round_to_fifty(lints.len())).unwrap();
        }),
    );
    updater.update_file_checked(
        "cargo dev update_lints",
        update_mode,
        "book/src/README.md",
        &mut update_text_region_fn("[There are over ", " lints included in this crate!]", |dst| {
            write!(dst, "{}", round_to_fifty(lints.len())).unwrap();
        }),
    );
    updater.update_file_checked(
        "cargo dev update_lints",
        update_mode,
        "CHANGELOG.md",
        &mut update_text_region_fn(
            "<!-- begin autogenerated links to lint list -->\n",
            "<!-- end autogenerated links to lint list -->",
            |dst| {
                for lint in lints
                    .iter()
                    .map(|l| l.name)
                    .chain(deprecated.iter().filter_map(|l| l.name.strip_prefix("clippy::")))
                    .chain(renamed.iter().filter_map(|l| l.old_name.strip_prefix("clippy::")))
                    .sorted()
                {
                    writeln!(dst, "[`{lint}`]: {DOCS_LINK}#{lint}").unwrap();
                }
            },
        ),
    );
    updater.update_file_checked(
        "cargo dev update_lints",
        update_mode,
        "clippy_lints/src/deprecated_lints.rs",
        &mut |_, src, dst| {
            let mut cursor = Cursor::new(src);
            assert!(
                cursor.find_ident("declare_with_version").is_some()
                    && cursor.find_ident("declare_with_version").is_some(),
                "error reading deprecated lints"
            );
            dst.push_str(&src[..cursor.pos() as usize]);
            dst.push_str("! { DEPRECATED(DEPRECATED_VERSION) = [\n");
            for lint in deprecated {
                write!(
                    dst,
                    "    #[clippy::version = \"{}\"]\n    (\"{}\", \"{}\"),\n",
                    lint.version, lint.name, lint.reason,
                )
                .unwrap();
            }
            dst.push_str(
                "]}\n\n\
                    #[rustfmt::skip]\n\
                    declare_with_version! { RENAMED(RENAMED_VERSION) = [\n\
                ",
            );
            for lint in renamed {
                write!(
                    dst,
                    "    #[clippy::version = \"{}\"]\n    (\"{}\", \"{}\"),\n",
                    lint.version, lint.old_name, lint.new_name,
                )
                .unwrap();
            }
            dst.push_str("]}\n");
            UpdateStatus::from_changed(src != dst)
        },
    );
    updater.update_file_checked(
        "cargo dev update_lints",
        update_mode,
        "tests/ui/deprecated.rs",
        &mut |_, src, dst| {
            dst.push_str(GENERATED_FILE_COMMENT);
            for lint in deprecated {
                writeln!(dst, "#![warn({})] //~ ERROR: lint `{}`", lint.name, lint.name).unwrap();
            }
            dst.push_str("\nfn main() {}\n");
            UpdateStatus::from_changed(src != dst)
        },
    );
    updater.update_file_checked(
        "cargo dev update_lints",
        update_mode,
        "tests/ui/rename.rs",
        &mut move |_, src, dst| {
            let mut seen_lints = HashSet::new();
            dst.push_str(GENERATED_FILE_COMMENT);
            dst.push_str("#![allow(clippy::duplicated_attributes)]\n");
            for lint in renamed {
                if seen_lints.insert(lint.new_name) {
                    writeln!(dst, "#![allow({})]", lint.new_name).unwrap();
                }
            }
            seen_lints.clear();
            for lint in renamed {
                if seen_lints.insert(lint.old_name) {
                    writeln!(dst, "#![warn({})] //~ ERROR: lint `{}`", lint.old_name, lint.old_name).unwrap();
                }
            }
            dst.push_str("\nfn main() {}\n");
            UpdateStatus::from_changed(src != dst)
        },
    );
    for (crate_name, lints) in lints.iter().into_group_map_by(|&l| {
        let Some(path::Component::Normal(name)) = l.path.components().next() else {
            // All paths should start with `{crate_name}/src` when parsed from `find_lint_decls`
            panic!("internal error: can't read crate name from path `{}`", l.path.display());
        };
        name
    }) {
        updater.update_file_checked(
            "cargo dev update_lints",
            update_mode,
            Path::new(crate_name).join("src/lib.rs"),
            &mut update_text_region_fn(
                "// begin lints modules, do not remove this comment, it's used in `update_lints`\n",
                "// end lints modules, do not remove this comment, it's used in `update_lints`",
                |dst| {
                    for lint_mod in lints
                        .iter()
                        .filter(|l| !l.module.is_empty())
                        .map(|l| l.module.split_once("::").map_or(l.module, |x| x.0))
                        .sorted()
                        .dedup()
                    {
                        writeln!(dst, "mod {lint_mod};").unwrap();
                    }
                },
            ),
        );
        updater.update_file_checked(
            "cargo dev update_lints",
            update_mode,
            Path::new(crate_name).join("src/declared_lints.rs"),
            &mut |_, src, dst| {
                dst.push_str(GENERATED_FILE_COMMENT);
                dst.push_str("pub static LINTS: &[&::declare_clippy_lint::LintInfo] = &[\n");
                for (module_path, lint_name) in lints.iter().map(|l| (&l.module, l.name.to_uppercase())).sorted() {
                    if module_path.is_empty() {
                        writeln!(dst, "    crate::{lint_name}_INFO,").unwrap();
                    } else {
                        writeln!(dst, "    crate::{module_path}::{lint_name}_INFO,").unwrap();
                    }
                }
                dst.push_str("];\n");
                UpdateStatus::from_changed(src != dst)
            },
        );
    }
}

fn round_to_fifty(count: usize) -> usize {
    count / 50 * 50
}