    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255
    256
    257
    258
    259
    260
    261
    262
    263
    264
    265
    266
    267
    268
    269
    270
    271
    272
    273
    274
    275
    276
    277
    278
    279
    280
    281
    282
    283
    284
    285
    286
    287
    288
    289
    290
    291
    292
    293
    294
    295
    296
    297
    298
    299
    300
    301
    302
    303
    304
    305
    306
    307
    308
    309
    310
    311
    312
    313
    314
    315
    316
    317
    318
    319
    320
    321
    322
    323
    324
    325
    326
    327
    328
    329
    330
    331
    332
    333
    334
    335
    336
    337
    338
    339
    340
    341
    342
    343
    344
    345
    346
    347
    348
    349
    350
    351
    352
    353
    354
    355
    356
    357
    358
    359
    360
    361
    362
    363
    364
    365
    366
    367
    368
    369
    370
    371
    372
    373
    374
    375
    376
    377
    378
    379
    380
    381
    382
    383
    384
    385
    386
    387
    388
    389
    390
    391
    392
    393
    394
    395
    396
    397
    398
    399
    400
    401
    402
    403
    404
    405
    406
    407
    408
    409
    410
    411
    412
    413
    414
    415
    416
    417
    418
    419
    420
    421
    422
    423
    424
    425
    426
    427
    428
    429
    430
    431
    432
    433
    434
    435
    436
    437
    438
    439
    440
    441
    442
    443
    444
    445
    446
    447
    448
    449
    450
    451
    452
    453
    454
    455
    456
    457
    458
    459
    460
    461
    462
    463
    464
    465
    466
    467
    468
    469
    470
    471
    472
    473
    474
    475
    476

    use crate::core::dependency::DepKind;
    use crate::core::FeatureValue::Dep;
    use crate::core::{Edition, FeatureValue, Package};
    use crate::util::interning::InternedString;
    use crate::{CargoResult, GlobalContext};
    use annotate_snippets::{Level, Renderer, Snippet};
    use cargo_util_schemas::manifest::{TomlLintLevel, TomlToolLints};
    use pathdiff::diff_paths;
    use std::collections::HashSet;
    use std::fmt::Display;
    use std::ops::Range;
    use std::path::Path;
    use toml_edit::ImDocument;

    fn get_span(document: &ImDocument<String>, path: &[&str], get_value: bool) -> Option<Range<usize>> {
        let mut table = document.as_item().as_table_like().unwrap();
        let mut iter = path.into_iter().peekable();
        while let Some(key) = iter.next() {
            let (key, item) = table.get_key_value(key).unwrap();
            if iter.peek().is_none() {
                return if get_value {
                    item.span()
                } else {
                    let leaf_decor = key.dotted_decor();
                    let leaf_prefix_span = leaf_decor.prefix().and_then(|p| p.span());
                    let leaf_suffix_span = leaf_decor.suffix().and_then(|s| s.span());
                    if let (Some(leaf_prefix_span), Some(leaf_suffix_span)) =
                        (leaf_prefix_span, leaf_suffix_span)
                    {
                        Some(leaf_prefix_span.start..leaf_suffix_span.end)
                    } else {
                        key.span()
                    }
                };
            }
            if item.is_table_like() {
                table = item.as_table_like().unwrap();
            }
            if item.is_array() && iter.peek().is_some() {
                let array = item.as_array().unwrap();
                let next = iter.next().unwrap();
                return array.iter().find_map(|item| {
                    if next == &item.to_string() {
                        item.span()
                    } else {
                        None
                    }
                });
            }
        }
        None
    }

    /// Gets the relative path to a manifest from the current working directory, or
    /// the absolute path of the manifest if a relative path cannot be constructed
    fn rel_cwd_manifest_path(path: &Path, gctx: &GlobalContext) -> String {
        diff_paths(path, gctx.cwd())
            .unwrap_or_else(|| path.to_path_buf())
            .display()
            .to_string()
    }

    #[derive(Copy, Clone, Debug)]
    pub struct LintGroup {
        pub name: &'static str,
        pub default_level: LintLevel,
        pub desc: &'static str,
        pub edition_lint_opts: Option<(Edition, LintLevel)>,
    }

    const TEST_DUMMY_UNSTABLE: LintGroup = LintGroup {
        name: "test_dummy_unstable",
        desc: "test_dummy_unstable is meant to only be used in tests",
        default_level: LintLevel::Allow,
        edition_lint_opts: None,
    };

    #[derive(Copy, Clone, Debug)]
    pub struct Lint {
        pub name: &'static str,
        pub desc: &'static str,
        pub groups: &'static [LintGroup],
        pub default_level: LintLevel,
        pub edition_lint_opts: Option<(Edition, LintLevel)>,
    }

    impl Lint {
        pub fn level(
            &self,
            pkg_lints: &TomlToolLints,
            edition: Edition,
        ) -> (LintLevel, LintLevelReason) {
            self.groups
                .iter()
                .map(|g| {
                    (
                        g.name,
                        level_priority(
                            g.name,
                            g.default_level,
                            g.edition_lint_opts,
                            pkg_lints,
                            edition,
                        ),
                    )
                })
                .chain(std::iter::once((
                    self.name,
                    level_priority(
                        self.name,
                        self.default_level,
                        self.edition_lint_opts,
                        pkg_lints,
                        edition,
                    ),
                )))
                .max_by_key(|(n, (l, _, p))| (l == &LintLevel::Forbid, *p, std::cmp::Reverse(*n)))
                .map(|(_, (l, r, _))| (l, r))
                .unwrap()
        }
    }

    #[derive(Copy, Clone, Debug, PartialEq)]
    pub enum LintLevel {
        Allow,
        Warn,
        Deny,
        Forbid,
    }

    impl Display for LintLevel {
        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
            match self {
                LintLevel::Allow => write!(f, "allow"),
                LintLevel::Warn => write!(f, "warn"),
                LintLevel::Deny => write!(f, "deny"),
                LintLevel::Forbid => write!(f, "forbid"),
            }
        }
    }

    impl LintLevel {
        pub fn to_diagnostic_level(self) -> Level {
            match self {
                LintLevel::Allow => unreachable!("allow does not map to a diagnostic level"),
                LintLevel::Warn => Level::Warning,
                LintLevel::Deny => Level::Error,
                LintLevel::Forbid => Level::Error,
            }
        }
    }

    impl From<TomlLintLevel> for LintLevel {
        fn from(toml_lint_level: TomlLintLevel) -> LintLevel {
            match toml_lint_level {
                TomlLintLevel::Allow => LintLevel::Allow,
                TomlLintLevel::Warn => LintLevel::Warn,
                TomlLintLevel::Deny => LintLevel::Deny,
                TomlLintLevel::Forbid => LintLevel::Forbid,
            }
        }
    }

    #[derive(Copy, Clone, Debug)]
    pub enum LintLevelReason {
        Default,
        Edition(Edition),
        Package,
    }

    impl Display for LintLevelReason {
        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
            match self {
                LintLevelReason::Default => write!(f, "by default"),
                LintLevelReason::Edition(edition) => write!(f, "in edition {}", edition),
                LintLevelReason::Package => write!(f, "in `[lints]`"),
            }
        }
    }

    fn level_priority(
        name: &str,
        default_level: LintLevel,
        edition_lint_opts: Option<(Edition, LintLevel)>,
        pkg_lints: &TomlToolLints,
        edition: Edition,
    ) -> (LintLevel, LintLevelReason, i8) {
        let (unspecified_level, reason) = if let Some(level) = edition_lint_opts
            .filter(|(e, _)| edition >= *e)
            .map(|(_, l)| l)
        {
            (level, LintLevelReason::Edition(edition))
        } else {
            (default_level, LintLevelReason::Default)
        };

        // Don't allow the group to be overridden if the level is `Forbid`
        if unspecified_level == LintLevel::Forbid {
            return (unspecified_level, reason, 0);
        }

        if let Some(defined_level) = pkg_lints.get(name) {
            (
                defined_level.level().into(),
                LintLevelReason::Package,
                defined_level.priority(),
            )
        } else {
            (unspecified_level, reason, 0)
        }
    }

    const IM_A_TEAPOT: Lint = Lint {
        name: "im_a_teapot",
        desc: "`im_a_teapot` is specified",
        groups: &[TEST_DUMMY_UNSTABLE],
        default_level: LintLevel::Allow,
        edition_lint_opts: None,
    };

    pub fn check_im_a_teapot(
        pkg: &Package,
        path: &Path,
        pkg_lints: &TomlToolLints,
        error_count: &mut usize,
        gctx: &GlobalContext,
    ) -> CargoResult<()> {
        let manifest = pkg.manifest();
        let (lint_level, reason) = IM_A_TEAPOT.level(pkg_lints, manifest.edition());
        if lint_level == LintLevel::Allow {
            return Ok(());
        }

        if manifest
            .resolved_toml()
            .package()
            .is_some_and(|p| p.im_a_teapot.is_some())
        {
            if lint_level == LintLevel::Forbid || lint_level == LintLevel::Deny {
                *error_count += 1;
            }
            let level = lint_level.to_diagnostic_level();
            let manifest_path = rel_cwd_manifest_path(path, gctx);
            let emitted_reason = format!(
                "`cargo::{}` is set to `{lint_level}` {reason}",
                IM_A_TEAPOT.name
            );

            let key_span = get_span(manifest.document(), &["package", "im-a-teapot"], false).unwrap();
            let value_span = get_span(manifest.document(), &["package", "im-a-teapot"], true).unwrap();
            let message = level
                .title(IM_A_TEAPOT.desc)
                .snippet(
                    Snippet::source(manifest.contents())
                        .origin(&manifest_path)
                        .annotation(level.span(key_span.start..value_span.end))
                        .fold(true),
                )
                .footer(Level::Note.title(&emitted_reason));
            let renderer = Renderer::styled().term_width(
                gctx.shell()
                    .err_width()
                    .diagnostic_terminal_width()
                    .unwrap_or(annotate_snippets::renderer::DEFAULT_TERM_WIDTH),
            );
            writeln!(gctx.shell().err(), "{}", renderer.render(message))?;
        }
        Ok(())
    }

    /// 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:<name>` (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]
    ///
    /// [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
    const IMPLICIT_FEATURES: Lint = Lint {
        name: "implicit_features",
        desc: "implicit features for optional dependencies is deprecated and will be unavailable in the 2024 edition",
        groups: &[],
        default_level: LintLevel::Allow,
        edition_lint_opts: None,
    };

    pub fn check_implicit_features(
        pkg: &Package,
        path: &Path,
        pkg_lints: &TomlToolLints,
        error_count: &mut usize,
        gctx: &GlobalContext,
    ) -> CargoResult<()> {
        let edition = pkg.manifest().edition();
        // In Edition 2024+, instead of creating optional features, the dependencies are unused.
        // See `UNUSED_OPTIONAL_DEPENDENCY`
        if edition >= Edition::Edition2024 {
            return Ok(());
        }

        let (lint_level, reason) = IMPLICIT_FEATURES.level(pkg_lints, edition);
        if lint_level == LintLevel::Allow {
            return Ok(());
        }

        let manifest = pkg.manifest();
        let activated_opt_deps = manifest
            .resolved_toml()
            .features()
            .map(|map| {
                map.values()
                    .flatten()
                    .filter_map(|f| match FeatureValue::new(InternedString::new(f)) {
                        Dep { dep_name } => Some(dep_name.as_str()),
                        _ => None,
                    })
                    .collect::<HashSet<_>>()
            })
            .unwrap_or_default();

        let mut emitted_source = None;
        for dep in manifest.dependencies() {
            let dep_name_in_toml = dep.name_in_toml();
            if !dep.is_optional() || activated_opt_deps.contains(dep_name_in_toml.as_str()) {
                continue;
            }
            if lint_level == LintLevel::Forbid || lint_level == LintLevel::Deny {
                *error_count += 1;
            }
            let mut toml_path = vec![dep.kind().kind_table(), dep_name_in_toml.as_str()];
            let platform = dep.platform().map(|p| p.to_string());
            if let Some(platform) = platform.as_ref() {
                toml_path.insert(0, platform);
                toml_path.insert(0, "target");
            }
            let level = lint_level.to_diagnostic_level();
            let manifest_path = rel_cwd_manifest_path(path, gctx);
            let mut message = level.title(IMPLICIT_FEATURES.desc).snippet(
                Snippet::source(manifest.contents())
                    .origin(&manifest_path)
                    .annotation(level.span(get_span(manifest.document(), &toml_path, false).unwrap()))
                    .fold(true),
            );
            if emitted_source.is_none() {
                emitted_source = Some(format!(
                    "`cargo::{}` is set to `{lint_level}` {reason}",
                    IMPLICIT_FEATURES.name
                ));
                message = message.footer(Level::Note.title(emitted_source.as_ref().unwrap()));
            }
            let renderer = Renderer::styled().term_width(
                gctx.shell()
                    .err_width()
                    .diagnostic_terminal_width()
                    .unwrap_or(annotate_snippets::renderer::DEFAULT_TERM_WIDTH),
            );
            writeln!(gctx.shell().err(), "{}", renderer.render(message))?;
        }
        Ok(())
    }

    const UNUSED_OPTIONAL_DEPENDENCY: Lint = Lint {
        name: "unused_optional_dependency",
        desc: "unused optional dependency",
        groups: &[],
        default_level: LintLevel::Warn,
        edition_lint_opts: None,
    };

    pub fn unused_dependencies(
        pkg: &Package,
        path: &Path,
        pkg_lints: &TomlToolLints,
        error_count: &mut usize,
        gctx: &GlobalContext,
    ) -> CargoResult<()> {
        let edition = pkg.manifest().edition();
        // Unused optional dependencies can only exist on edition 2024+
        if edition < Edition::Edition2024 {
            return Ok(());
        }

        let (lint_level, reason) = UNUSED_OPTIONAL_DEPENDENCY.level(pkg_lints, edition);
        if lint_level == LintLevel::Allow {
            return Ok(());
        }
        let mut emitted_source = None;
        let manifest = pkg.manifest();
        let original_toml = manifest.original_toml();
        // Unused dependencies were stripped from the manifest, leaving only the used ones
        let used_dependencies = manifest
            .dependencies()
            .into_iter()
            .map(|d| d.name_in_toml().to_string())
            .collect::<HashSet<String>>();
        let mut orig_deps = vec![
            (
                original_toml.dependencies.as_ref(),
                vec![DepKind::Normal.kind_table()],
            ),
            (
                original_toml.dev_dependencies.as_ref(),
                vec![DepKind::Development.kind_table()],
            ),
            (
                original_toml.build_dependencies.as_ref(),
                vec![DepKind::Build.kind_table()],
            ),
        ];
        for (name, platform) in original_toml.target.iter().flatten() {
            orig_deps.push((
                platform.dependencies.as_ref(),
                vec!["target", name, DepKind::Normal.kind_table()],
            ));
            orig_deps.push((
                platform.dev_dependencies.as_ref(),
                vec!["target", name, DepKind::Development.kind_table()],
            ));
            orig_deps.push((
                platform.build_dependencies.as_ref(),
                vec!["target", name, DepKind::Normal.kind_table()],
            ));
        }
        for (deps, toml_path) in orig_deps {
            if let Some(deps) = deps {
                for name in deps.keys() {
                    if !used_dependencies.contains(name.as_str()) {
                        if lint_level == LintLevel::Forbid || lint_level == LintLevel::Deny {
                            *error_count += 1;
                        }
                        let toml_path = toml_path
                            .iter()
                            .map(|s| *s)
                            .chain(std::iter::once(name.as_str()))
                            .collect::<Vec<_>>();
                        let level = lint_level.to_diagnostic_level();
                        let manifest_path = rel_cwd_manifest_path(path, gctx);

                        let mut message = level.title(UNUSED_OPTIONAL_DEPENDENCY.desc).snippet(
                            Snippet::source(manifest.contents())
                                .origin(&manifest_path)
                                .annotation(level.span(
                                    get_span(manifest.document(), toml_path.as_slice(), false).unwrap(),
                                ))
                                .fold(true),
                        );
                        if emitted_source.is_none() {
                            emitted_source = Some(format!(
                                "`cargo::{}` is set to `{lint_level}` {reason}",
                                UNUSED_OPTIONAL_DEPENDENCY.name
                            ));
                            message =
                                message.footer(Level::Note.title(emitted_source.as_ref().unwrap()));
                        }
                        let help = format!(
                            "remove the dependency or activate it in a feature with `dep:{name}`"
                        );
                        message = message.footer(Level::Help.title(&help));
                        let renderer = Renderer::styled().term_width(
                            gctx.shell()
                                .err_width()
                                .diagnostic_terminal_width()
                                .unwrap_or(annotate_snippets::renderer::DEFAULT_TERM_WIDTH),
                        );
                        writeln!(gctx.shell().err(), "{}", renderer.render(message))?;
                    }
                }
            }
        }
        Ok(())
    }