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
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
use std::collections::{BTreeMap, HashMap};
use std::fmt;
use std::hash::{Hash, Hasher};
use std::path::{Path, PathBuf};
use std::rc::Rc;
use std::sync::Arc;

use anyhow::Context as _;
use semver::Version;
use serde::ser;
use serde::Serialize;
use toml_edit::easy as toml;
use url::Url;

use crate::core::compiler::{CompileKind, CrateType};
use crate::core::resolver::ResolveBehavior;
use crate::core::{Dependency, PackageId, PackageIdSpec, SourceId, Summary};
use crate::core::{Edition, Feature, Features, WorkspaceConfig};
use crate::util::errors::*;
use crate::util::interning::InternedString;
use crate::util::toml::{TomlManifest, TomlProfiles};
use crate::util::{short_hash, Config, Filesystem};

pub enum EitherManifest {
    Real(Manifest),
    Virtual(VirtualManifest),
}

/// Contains all the information about a package, as loaded from a `Cargo.toml`.
///
/// This is deserialized using the [`TomlManifest`] type.
#[derive(Clone, Debug)]
pub struct Manifest {
    summary: Summary,
    targets: Vec<Target>,
    default_kind: Option<CompileKind>,
    forced_kind: Option<CompileKind>,
    links: Option<String>,
    warnings: Warnings,
    exclude: Vec<String>,
    include: Vec<String>,
    metadata: ManifestMetadata,
    custom_metadata: Option<toml::Value>,
    profiles: Option<TomlProfiles>,
    publish: Option<Vec<String>>,
    replace: Vec<(PackageIdSpec, Dependency)>,
    patch: HashMap<Url, Vec<Dependency>>,
    workspace: WorkspaceConfig,
    original: Rc<TomlManifest>,
    unstable_features: Features,
    edition: Edition,
    rust_version: Option<String>,
    im_a_teapot: Option<bool>,
    default_run: Option<String>,
    metabuild: Option<Vec<String>>,
    resolve_behavior: Option<ResolveBehavior>,
}

/// When parsing `Cargo.toml`, some warnings should silenced
/// if the manifest comes from a dependency. `ManifestWarning`
/// allows this delayed emission of warnings.
#[derive(Clone, Debug)]
pub struct DelayedWarning {
    pub message: String,
    pub is_critical: bool,
}

#[derive(Clone, Debug)]
pub struct Warnings(Vec<DelayedWarning>);

#[derive(Clone, Debug)]
pub struct VirtualManifest {
    replace: Vec<(PackageIdSpec, Dependency)>,
    patch: HashMap<Url, Vec<Dependency>>,
    workspace: WorkspaceConfig,
    profiles: Option<TomlProfiles>,
    warnings: Warnings,
    features: Features,
    resolve_behavior: Option<ResolveBehavior>,
}

/// General metadata about a package which is just blindly uploaded to the
/// registry.
///
/// Note that many of these fields can contain invalid values such as the
/// homepage, repository, documentation, or license. These fields are not
/// validated by cargo itself, but rather it is up to the registry when uploaded
/// to validate these fields. Cargo will itself accept any valid TOML
/// specification for these values.
#[derive(PartialEq, Clone, Debug)]
pub struct ManifestMetadata {
    pub authors: Vec<String>,
    pub keywords: Vec<String>,
    pub categories: Vec<String>,
    pub license: Option<String>,
    pub license_file: Option<String>,
    pub description: Option<String>,   // Not in Markdown
    pub readme: Option<String>,        // File, not contents
    pub homepage: Option<String>,      // URL
    pub repository: Option<String>,    // URL
    pub documentation: Option<String>, // URL
    pub badges: BTreeMap<String, BTreeMap<String, String>>,
    pub links: Option<String>,
}

#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
pub enum TargetKind {
    Lib(Vec<CrateType>),
    Bin,
    Test,
    Bench,
    ExampleLib(Vec<CrateType>),
    ExampleBin,
    CustomBuild,
}

impl ser::Serialize for TargetKind {
    fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
    where
        S: ser::Serializer,
    {
        use self::TargetKind::*;
        match self {
            Lib(kinds) => s.collect_seq(kinds.iter().map(|t| t.to_string())),
            Bin => ["bin"].serialize(s),
            ExampleBin | ExampleLib(_) => ["example"].serialize(s),
            Test => ["test"].serialize(s),
            CustomBuild => ["custom-build"].serialize(s),
            Bench => ["bench"].serialize(s),
        }
    }
}

impl fmt::Debug for TargetKind {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        use self::TargetKind::*;
        match *self {
            Lib(ref kinds) => kinds.fmt(f),
            Bin => "bin".fmt(f),
            ExampleBin | ExampleLib(_) => "example".fmt(f),
            Test => "test".fmt(f),
            CustomBuild => "custom-build".fmt(f),
            Bench => "bench".fmt(f),
        }
    }
}

impl TargetKind {
    pub fn description(&self) -> &'static str {
        match self {
            TargetKind::Lib(..) => "lib",
            TargetKind::Bin => "bin",
            TargetKind::Test => "integration-test",
            TargetKind::ExampleBin | TargetKind::ExampleLib(..) => "example",
            TargetKind::Bench => "bench",
            TargetKind::CustomBuild => "build-script",
        }
    }

    /// Returns whether production of this artifact requires the object files
    /// from dependencies to be available.
    ///
    /// This only returns `false` when all we're producing is an rlib, otherwise
    /// it will return `true`.
    pub fn requires_upstream_objects(&self) -> bool {
        match self {
            TargetKind::Lib(kinds) | TargetKind::ExampleLib(kinds) => {
                kinds.iter().any(|k| k.requires_upstream_objects())
            }
            _ => true,
        }
    }

    /// Returns the arguments suitable for `--crate-type` to pass to rustc.
    pub fn rustc_crate_types(&self) -> Vec<CrateType> {
        match self {
            TargetKind::Lib(kinds) | TargetKind::ExampleLib(kinds) => kinds.clone(),
            TargetKind::CustomBuild
            | TargetKind::Bench
            | TargetKind::Test
            | TargetKind::ExampleBin
            | TargetKind::Bin => vec![CrateType::Bin],
        }
    }
}

/// Information about a binary, a library, an example, etc. that is part of the
/// package.
#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
pub struct Target {
    inner: Arc<TargetInner>,
}

#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
struct TargetInner {
    kind: TargetKind,
    name: String,
    // Note that `bin_name` is used for the cargo-feature `different_binary_name`
    bin_name: Option<String>,
    // Note that the `src_path` here is excluded from the `Hash` implementation
    // as it's absolute currently and is otherwise a little too brittle for
    // causing rebuilds. Instead the hash for the path that we send to the
    // compiler is handled elsewhere.
    src_path: TargetSourcePath,
    required_features: Option<Vec<String>>,
    tested: bool,
    benched: bool,
    doc: bool,
    doctest: bool,
    harness: bool, // whether to use the test harness (--test)
    for_host: bool,
    proc_macro: bool,
    edition: Edition,
}

#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
pub enum TargetSourcePath {
    Path(PathBuf),
    Metabuild,
}

impl TargetSourcePath {
    pub fn path(&self) -> Option<&Path> {
        match self {
            TargetSourcePath::Path(path) => Some(path.as_ref()),
            TargetSourcePath::Metabuild => None,
        }
    }

    pub fn is_path(&self) -> bool {
        matches!(self, TargetSourcePath::Path(_))
    }
}

impl Hash for TargetSourcePath {
    fn hash<H: Hasher>(&self, _: &mut H) {
        // ...
    }
}

impl fmt::Debug for TargetSourcePath {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            TargetSourcePath::Path(path) => path.fmt(f),
            TargetSourcePath::Metabuild => "metabuild".fmt(f),
        }
    }
}

impl From<PathBuf> for TargetSourcePath {
    fn from(path: PathBuf) -> Self {
        assert!(path.is_absolute(), "`{}` is not absolute", path.display());
        TargetSourcePath::Path(path)
    }
}

#[derive(Serialize)]
struct SerializedTarget<'a> {
    /// Is this a `--bin bin`, `--lib`, `--example ex`?
    /// Serialized as a list of strings for historical reasons.
    kind: &'a TargetKind,
    /// Corresponds to `--crate-type` compiler attribute.
    /// See <https://doc.rust-lang.org/reference/linkage.html>
    crate_types: Vec<CrateType>,
    name: &'a str,
    src_path: Option<&'a PathBuf>,
    edition: &'a str,
    #[serde(rename = "required-features", skip_serializing_if = "Option::is_none")]
    required_features: Option<Vec<&'a str>>,
    /// Whether docs should be built for the target via `cargo doc`
    /// See <https://doc.rust-lang.org/cargo/commands/cargo-doc.html#target-selection>
    doc: bool,
    doctest: bool,
    /// Whether tests should be run for the target (`test` field in `Cargo.toml`)
    test: bool,
}

impl ser::Serialize for Target {
    fn serialize<S: ser::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
        let src_path = match self.src_path() {
            TargetSourcePath::Path(p) => Some(p),
            // Unfortunately getting the correct path would require access to
            // target_dir, which is not available here.
            TargetSourcePath::Metabuild => None,
        };
        SerializedTarget {
            kind: self.kind(),
            crate_types: self.rustc_crate_types(),
            name: self.name(),
            src_path,
            edition: &self.edition().to_string(),
            required_features: self
                .required_features()
                .map(|rf| rf.iter().map(|s| s.as_str()).collect()),
            doc: self.documented(),
            doctest: self.doctested() && self.doctestable(),
            test: self.tested(),
        }
        .serialize(s)
    }
}

impl fmt::Debug for Target {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.inner.fmt(f)
    }
}

compact_debug! {
    impl fmt::Debug for TargetInner {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            let (default, default_name) = {
                match &self.kind {
                    TargetKind::Lib(kinds) => {
                        (
                            Target::lib_target(
                                &self.name,
                                kinds.clone(),
                                self.src_path.path().unwrap().to_path_buf(),
                                self.edition,
                            ).inner,
                            format!("lib_target({:?}, {:?}, {:?}, {:?})",
                                    self.name, kinds, self.src_path, self.edition),
                        )
                    }
                    TargetKind::CustomBuild => {
                        match self.src_path {
                            TargetSourcePath::Path(ref path) => {
                                (
                                    Target::custom_build_target(
                                        &self.name,
                                        path.to_path_buf(),
                                        self.edition,
                                    ).inner,
                                    format!("custom_build_target({:?}, {:?}, {:?})",
                                            self.name, path, self.edition),
                                )
                            }
                            TargetSourcePath::Metabuild => {
                                (
                                    Target::metabuild_target(&self.name).inner,
                                    format!("metabuild_target({:?})", self.name),
                                )
                            }
                        }
                    }
                    _ => (
                        Target::new(self.src_path.clone(), self.edition).inner,
                        format!("with_path({:?}, {:?})", self.src_path, self.edition),
                    ),
                }
            };
            [debug_the_fields(
                kind
                name
                bin_name
                src_path
                required_features
                tested
                benched
                doc
                doctest
                harness
                for_host
                proc_macro
                edition
            )]
        }
    }
}

impl Manifest {
    pub fn new(
        summary: Summary,
        default_kind: Option<CompileKind>,
        forced_kind: Option<CompileKind>,
        targets: Vec<Target>,
        exclude: Vec<String>,
        include: Vec<String>,
        links: Option<String>,
        metadata: ManifestMetadata,
        custom_metadata: Option<toml::Value>,
        profiles: Option<TomlProfiles>,
        publish: Option<Vec<String>>,
        replace: Vec<(PackageIdSpec, Dependency)>,
        patch: HashMap<Url, Vec<Dependency>>,
        workspace: WorkspaceConfig,
        unstable_features: Features,
        edition: Edition,
        rust_version: Option<String>,
        im_a_teapot: Option<bool>,
        default_run: Option<String>,
        original: Rc<TomlManifest>,
        metabuild: Option<Vec<String>>,
        resolve_behavior: Option<ResolveBehavior>,
    ) -> Manifest {
        Manifest {
            summary,
            default_kind,
            forced_kind,
            targets,
            warnings: Warnings::new(),
            exclude,
            include,
            links,
            metadata,
            custom_metadata,
            profiles,
            publish,
            replace,
            patch,
            workspace,
            unstable_features,
            edition,
            rust_version,
            original,
            im_a_teapot,
            default_run,
            metabuild,
            resolve_behavior,
        }
    }

    pub fn dependencies(&self) -> &[Dependency] {
        self.summary.dependencies()
    }
    pub fn default_kind(&self) -> Option<CompileKind> {
        self.default_kind
    }
    pub fn forced_kind(&self) -> Option<CompileKind> {
        self.forced_kind
    }
    pub fn exclude(&self) -> &[String] {
        &self.exclude
    }
    pub fn include(&self) -> &[String] {
        &self.include
    }
    pub fn metadata(&self) -> &ManifestMetadata {
        &self.metadata
    }
    pub fn name(&self) -> InternedString {
        self.package_id().name()
    }
    pub fn package_id(&self) -> PackageId {
        self.summary.package_id()
    }
    pub fn summary(&self) -> &Summary {
        &self.summary
    }
    pub fn summary_mut(&mut self) -> &mut Summary {
        &mut self.summary
    }
    pub fn targets(&self) -> &[Target] {
        &self.targets
    }
    // It is used by cargo-c, please do not remove it
    pub fn targets_mut(&mut self) -> &mut [Target] {
        &mut self.targets
    }
    pub fn version(&self) -> &Version {
        self.package_id().version()
    }
    pub fn warnings_mut(&mut self) -> &mut Warnings {
        &mut self.warnings
    }
    pub fn warnings(&self) -> &Warnings {
        &self.warnings
    }
    pub fn profiles(&self) -> Option<&TomlProfiles> {
        self.profiles.as_ref()
    }
    pub fn publish(&self) -> &Option<Vec<String>> {
        &self.publish
    }
    pub fn replace(&self) -> &[(PackageIdSpec, Dependency)] {
        &self.replace
    }
    pub fn original(&self) -> &TomlManifest {
        &self.original
    }
    pub fn patch(&self) -> &HashMap<Url, Vec<Dependency>> {
        &self.patch
    }
    pub fn links(&self) -> Option<&str> {
        self.links.as_deref()
    }

    pub fn workspace_config(&self) -> &WorkspaceConfig {
        &self.workspace
    }

    /// Unstable, nightly features that are enabled in this manifest.
    pub fn unstable_features(&self) -> &Features {
        &self.unstable_features
    }

    /// The style of resolver behavior to use, declared with the `resolver` field.
    ///
    /// Returns `None` if it is not specified.
    pub fn resolve_behavior(&self) -> Option<ResolveBehavior> {
        self.resolve_behavior
    }

    pub fn map_source(self, to_replace: SourceId, replace_with: SourceId) -> Manifest {
        Manifest {
            summary: self.summary.map_source(to_replace, replace_with),
            ..self
        }
    }

    pub fn feature_gate(&self) -> CargoResult<()> {
        if self.im_a_teapot.is_some() {
            self.unstable_features
                .require(Feature::test_dummy_unstable())
                .with_context(|| {
                    "the `im-a-teapot` manifest key is unstable and may \
                     not work properly in England"
                })?;
        }

        if self.default_kind.is_some() || self.forced_kind.is_some() {
            self.unstable_features
                .require(Feature::per_package_target())
                .with_context(|| {
                    "the `package.default-target` and `package.forced-target` \
                     manifest keys are unstable and may not work properly"
                })?;
        }

        Ok(())
    }

    // Just a helper function to test out `-Z` flags on Cargo
    pub fn print_teapot(&self, config: &Config) {
        if let Some(teapot) = self.im_a_teapot {
            if config.cli_unstable().print_im_a_teapot {
                crate::drop_println!(config, "im-a-teapot = {}", teapot);
            }
        }
    }

    pub fn edition(&self) -> Edition {
        self.edition
    }

    pub fn rust_version(&self) -> Option<&str> {
        self.rust_version.as_deref()
    }

    pub fn custom_metadata(&self) -> Option<&toml::Value> {
        self.custom_metadata.as_ref()
    }

    pub fn default_run(&self) -> Option<&str> {
        self.default_run.as_deref()
    }

    pub fn metabuild(&self) -> Option<&Vec<String>> {
        self.metabuild.as_ref()
    }

    pub fn metabuild_path(&self, target_dir: Filesystem) -> PathBuf {
        let hash = short_hash(&self.package_id());
        target_dir
            .into_path_unlocked()
            .join(".metabuild")
            .join(format!("metabuild-{}-{}.rs", self.name(), hash))
    }
}

impl VirtualManifest {
    pub fn new(
        replace: Vec<(PackageIdSpec, Dependency)>,
        patch: HashMap<Url, Vec<Dependency>>,
        workspace: WorkspaceConfig,
        profiles: Option<TomlProfiles>,
        features: Features,
        resolve_behavior: Option<ResolveBehavior>,
    ) -> VirtualManifest {
        VirtualManifest {
            replace,
            patch,
            workspace,
            profiles,
            warnings: Warnings::new(),
            features,
            resolve_behavior,
        }
    }

    pub fn replace(&self) -> &[(PackageIdSpec, Dependency)] {
        &self.replace
    }

    pub fn patch(&self) -> &HashMap<Url, Vec<Dependency>> {
        &self.patch
    }

    pub fn workspace_config(&self) -> &WorkspaceConfig {
        &self.workspace
    }

    pub fn profiles(&self) -> Option<&TomlProfiles> {
        self.profiles.as_ref()
    }

    pub fn warnings_mut(&mut self) -> &mut Warnings {
        &mut self.warnings
    }

    pub fn warnings(&self) -> &Warnings {
        &self.warnings
    }

    pub fn unstable_features(&self) -> &Features {
        &self.features
    }

    /// The style of resolver behavior to use, declared with the `resolver` field.
    ///
    /// Returns `None` if it is not specified.
    pub fn resolve_behavior(&self) -> Option<ResolveBehavior> {
        self.resolve_behavior
    }
}

impl Target {
    fn new(src_path: TargetSourcePath, edition: Edition) -> Target {
        Target {
            inner: Arc::new(TargetInner {
                kind: TargetKind::Bin,
                name: String::new(),
                bin_name: None,
                src_path,
                required_features: None,
                doc: false,
                doctest: false,
                harness: true,
                for_host: false,
                proc_macro: false,
                edition,
                tested: true,
                benched: true,
            }),
        }
    }

    fn with_path(src_path: PathBuf, edition: Edition) -> Target {
        Target::new(TargetSourcePath::from(src_path), edition)
    }

    pub fn lib_target(
        name: &str,
        crate_targets: Vec<CrateType>,
        src_path: PathBuf,
        edition: Edition,
    ) -> Target {
        let mut target = Target::with_path(src_path, edition);
        target
            .set_kind(TargetKind::Lib(crate_targets))
            .set_name(name)
            .set_doctest(true)
            .set_doc(true);
        target
    }

    pub fn bin_target(
        name: &str,
        bin_name: Option<String>,
        src_path: PathBuf,
        required_features: Option<Vec<String>>,
        edition: Edition,
    ) -> Target {
        let mut target = Target::with_path(src_path, edition);
        target
            .set_kind(TargetKind::Bin)
            .set_name(name)
            .set_binary_name(bin_name)
            .set_required_features(required_features)
            .set_doc(true);
        target
    }

    /// Builds a `Target` corresponding to the `build = "build.rs"` entry.
    pub fn custom_build_target(name: &str, src_path: PathBuf, edition: Edition) -> Target {
        let mut target = Target::with_path(src_path, edition);
        target
            .set_kind(TargetKind::CustomBuild)
            .set_name(name)
            .set_for_host(true)
            .set_benched(false)
            .set_tested(false);
        target
    }

    pub fn metabuild_target(name: &str) -> Target {
        let mut target = Target::new(TargetSourcePath::Metabuild, Edition::Edition2018);
        target
            .set_kind(TargetKind::CustomBuild)
            .set_name(name)
            .set_for_host(true)
            .set_benched(false)
            .set_tested(false);
        target
    }

    pub fn example_target(
        name: &str,
        crate_targets: Vec<CrateType>,
        src_path: PathBuf,
        required_features: Option<Vec<String>>,
        edition: Edition,
    ) -> Target {
        let kind = if crate_targets.is_empty() || crate_targets.iter().all(|t| *t == CrateType::Bin)
        {
            TargetKind::ExampleBin
        } else {
            TargetKind::ExampleLib(crate_targets)
        };
        let mut target = Target::with_path(src_path, edition);
        target
            .set_kind(kind)
            .set_name(name)
            .set_required_features(required_features)
            .set_tested(false)
            .set_benched(false);
        target
    }

    pub fn test_target(
        name: &str,
        src_path: PathBuf,
        required_features: Option<Vec<String>>,
        edition: Edition,
    ) -> Target {
        let mut target = Target::with_path(src_path, edition);
        target
            .set_kind(TargetKind::Test)
            .set_name(name)
            .set_required_features(required_features)
            .set_benched(false);
        target
    }

    pub fn bench_target(
        name: &str,
        src_path: PathBuf,
        required_features: Option<Vec<String>>,
        edition: Edition,
    ) -> Target {
        let mut target = Target::with_path(src_path, edition);
        target
            .set_kind(TargetKind::Bench)
            .set_name(name)
            .set_required_features(required_features)
            .set_tested(false);
        target
    }

    pub fn name(&self) -> &str {
        &self.inner.name
    }
    pub fn crate_name(&self) -> String {
        self.name().replace("-", "_")
    }
    pub fn src_path(&self) -> &TargetSourcePath {
        &self.inner.src_path
    }
    pub fn set_src_path(&mut self, src_path: TargetSourcePath) {
        Arc::make_mut(&mut self.inner).src_path = src_path;
    }
    pub fn required_features(&self) -> Option<&Vec<String>> {
        self.inner.required_features.as_ref()
    }
    pub fn kind(&self) -> &TargetKind {
        &self.inner.kind
    }
    pub fn tested(&self) -> bool {
        self.inner.tested
    }
    pub fn harness(&self) -> bool {
        self.inner.harness
    }
    pub fn documented(&self) -> bool {
        self.inner.doc
    }
    // A plugin, proc-macro, or build-script.
    pub fn for_host(&self) -> bool {
        self.inner.for_host
    }
    pub fn proc_macro(&self) -> bool {
        self.inner.proc_macro
    }
    pub fn edition(&self) -> Edition {
        self.inner.edition
    }
    pub fn benched(&self) -> bool {
        self.inner.benched
    }
    pub fn doctested(&self) -> bool {
        self.inner.doctest
    }

    pub fn doctestable(&self) -> bool {
        match self.kind() {
            TargetKind::Lib(ref kinds) => kinds.iter().any(|k| {
                *k == CrateType::Rlib || *k == CrateType::Lib || *k == CrateType::ProcMacro
            }),
            _ => false,
        }
    }

    pub fn is_lib(&self) -> bool {
        matches!(self.kind(), TargetKind::Lib(_))
    }

    pub fn is_dylib(&self) -> bool {
        match self.kind() {
            TargetKind::Lib(libs) => libs.iter().any(|l| *l == CrateType::Dylib),
            _ => false,
        }
    }

    pub fn is_cdylib(&self) -> bool {
        match self.kind() {
            TargetKind::Lib(libs) => libs.iter().any(|l| *l == CrateType::Cdylib),
            _ => false,
        }
    }

    pub fn is_staticlib(&self) -> bool {
        match self.kind() {
            TargetKind::Lib(libs) => libs.iter().any(|l| *l == CrateType::Staticlib),
            _ => false,
        }
    }

    /// Returns whether this target produces an artifact which can be linked
    /// into a Rust crate.
    ///
    /// This only returns true for certain kinds of libraries.
    pub fn is_linkable(&self) -> bool {
        match self.kind() {
            TargetKind::Lib(kinds) => kinds.iter().any(|k| k.is_linkable()),
            _ => false,
        }
    }

    pub fn is_bin(&self) -> bool {
        *self.kind() == TargetKind::Bin
    }

    pub fn is_example(&self) -> bool {
        matches!(
            self.kind(),
            TargetKind::ExampleBin | TargetKind::ExampleLib(..)
        )
    }

    /// Returns `true` if it is a binary or executable example.
    /// NOTE: Tests are `false`!
    pub fn is_executable(&self) -> bool {
        self.is_bin() || self.is_exe_example()
    }

    /// Returns `true` if it is an executable example.
    pub fn is_exe_example(&self) -> bool {
        // Needed for --all-examples in contexts where only runnable examples make sense
        matches!(self.kind(), TargetKind::ExampleBin)
    }

    pub fn is_test(&self) -> bool {
        *self.kind() == TargetKind::Test
    }
    pub fn is_bench(&self) -> bool {
        *self.kind() == TargetKind::Bench
    }
    pub fn is_custom_build(&self) -> bool {
        *self.kind() == TargetKind::CustomBuild
    }

    /// Returns the arguments suitable for `--crate-type` to pass to rustc.
    pub fn rustc_crate_types(&self) -> Vec<CrateType> {
        self.kind().rustc_crate_types()
    }

    pub fn set_tested(&mut self, tested: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).tested = tested;
        self
    }
    pub fn set_benched(&mut self, benched: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).benched = benched;
        self
    }
    pub fn set_doctest(&mut self, doctest: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).doctest = doctest;
        self
    }
    pub fn set_for_host(&mut self, for_host: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).for_host = for_host;
        self
    }
    pub fn set_proc_macro(&mut self, proc_macro: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).proc_macro = proc_macro;
        self
    }
    pub fn set_edition(&mut self, edition: Edition) -> &mut Target {
        Arc::make_mut(&mut self.inner).edition = edition;
        self
    }
    pub fn set_harness(&mut self, harness: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).harness = harness;
        self
    }
    pub fn set_doc(&mut self, doc: bool) -> &mut Target {
        Arc::make_mut(&mut self.inner).doc = doc;
        self
    }
    pub fn set_kind(&mut self, kind: TargetKind) -> &mut Target {
        Arc::make_mut(&mut self.inner).kind = kind;
        self
    }
    pub fn set_name(&mut self, name: &str) -> &mut Target {
        Arc::make_mut(&mut self.inner).name = name.to_string();
        self
    }
    pub fn set_binary_name(&mut self, bin_name: Option<String>) -> &mut Target {
        Arc::make_mut(&mut self.inner).bin_name = bin_name;
        self
    }
    pub fn set_required_features(&mut self, required_features: Option<Vec<String>>) -> &mut Target {
        Arc::make_mut(&mut self.inner).required_features = required_features;
        self
    }
    pub fn binary_filename(&self) -> Option<String> {
        self.inner.bin_name.clone()
    }
    pub fn description_named(&self) -> String {
        match self.kind() {
            TargetKind::Lib(..) => "lib".to_string(),
            TargetKind::Bin => format!("bin \"{}\"", self.name()),
            TargetKind::Test => format!("test \"{}\"", self.name()),
            TargetKind::Bench => format!("bench \"{}\"", self.name()),
            TargetKind::ExampleLib(..) | TargetKind::ExampleBin => {
                format!("example \"{}\"", self.name())
            }
            TargetKind::CustomBuild => "build script".to_string(),
        }
    }
}

impl fmt::Display for Target {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self.kind() {
            TargetKind::Lib(..) => write!(f, "Target(lib)"),
            TargetKind::Bin => write!(f, "Target(bin: {})", self.name()),
            TargetKind::Test => write!(f, "Target(test: {})", self.name()),
            TargetKind::Bench => write!(f, "Target(bench: {})", self.name()),
            TargetKind::ExampleBin | TargetKind::ExampleLib(..) => {
                write!(f, "Target(example: {})", self.name())
            }
            TargetKind::CustomBuild => write!(f, "Target(script)"),
        }
    }
}

impl Warnings {
    fn new() -> Warnings {
        Warnings(Vec::new())
    }

    pub fn add_warning(&mut self, s: String) {
        self.0.push(DelayedWarning {
            message: s,
            is_critical: false,
        })
    }

    pub fn add_critical_warning(&mut self, s: String) {
        self.0.push(DelayedWarning {
            message: s,
            is_critical: true,
        })
    }

    pub fn warnings(&self) -> &[DelayedWarning] {
        &self.0
    }
}