bootstrap/core/config/
flags.rs

1//! Command-line interface of the bootstrap build system.
2//!
3//! This module implements the command-line parsing of the build system which
4//! has various flags to configure how it's run.
5
6use std::path::{Path, PathBuf};
7
8use clap::{CommandFactory, Parser, ValueEnum};
9use clap_complete::Generator;
10#[cfg(feature = "tracing")]
11use tracing::instrument;
12
13use crate::core::build_steps::perf::PerfArgs;
14use crate::core::build_steps::setup::Profile;
15use crate::core::builder::{Builder, Kind};
16use crate::core::config::Config;
17use crate::core::config::target_selection::{TargetSelectionList, target_selection_list};
18use crate::{Build, CodegenBackendKind, DocTests};
19
20#[derive(Copy, Clone, Default, Debug, ValueEnum)]
21pub enum Color {
22    Always,
23    Never,
24    #[default]
25    Auto,
26}
27
28/// Whether to deny warnings, emit them as warnings, or use the default behavior
29#[derive(Copy, Clone, Default, Debug, ValueEnum)]
30pub enum Warnings {
31    Deny,
32    Warn,
33    #[default]
34    Default,
35}
36
37/// Deserialized version of all flags for this compile.
38#[derive(Debug, Parser)]
39#[command(
40    override_usage = "x.py <subcommand> [options] [<paths>...]",
41    disable_help_subcommand(true),
42    about = "",
43    next_line_help(false)
44)]
45pub struct Flags {
46    #[command(subcommand)]
47    pub cmd: Subcommand,
48
49    #[arg(global = true, short, long, action = clap::ArgAction::Count)]
50    /// use verbose output (-vv for very verbose)
51    pub verbose: u8, // each extra -v after the first is passed to Cargo
52    #[arg(global = true, short, long)]
53    /// use incremental compilation
54    pub incremental: bool,
55    #[arg(global = true, long, value_hint = clap::ValueHint::FilePath, value_name = "FILE")]
56    /// TOML configuration file for build
57    pub config: Option<PathBuf>,
58    #[arg(global = true, long, value_hint = clap::ValueHint::DirPath, value_name = "DIR")]
59    /// Build directory, overrides `build.build-dir` in `bootstrap.toml`
60    pub build_dir: Option<PathBuf>,
61
62    #[arg(global = true, long, value_hint = clap::ValueHint::Other, value_name = "BUILD")]
63    /// host target of the stage0 compiler
64    pub build: Option<String>,
65
66    #[arg(global = true, long, value_hint = clap::ValueHint::Other, value_name = "HOST", value_parser = target_selection_list)]
67    /// host targets to build
68    pub host: Option<TargetSelectionList>,
69
70    #[arg(global = true, long, value_hint = clap::ValueHint::Other, value_name = "TARGET", value_parser = target_selection_list)]
71    /// target targets to build
72    pub target: Option<TargetSelectionList>,
73
74    #[arg(global = true, long, value_name = "PATH")]
75    /// build paths to exclude
76    pub exclude: Vec<PathBuf>, // keeping for client backward compatibility
77    #[arg(global = true, long, value_name = "PATH")]
78    /// build paths to skip
79    pub skip: Vec<PathBuf>,
80    #[arg(global = true, long)]
81    /// include default paths in addition to the provided ones
82    pub include_default_paths: bool,
83
84    /// rustc error format
85    #[arg(global = true, value_hint = clap::ValueHint::Other, long)]
86    pub rustc_error_format: Option<String>,
87
88    #[arg(global = true, long, value_hint = clap::ValueHint::CommandString, value_name = "CMD")]
89    /// command to run on failure
90    pub on_fail: Option<String>,
91    #[arg(global = true, long)]
92    /// dry run; don't build anything
93    pub dry_run: bool,
94    /// Indicates whether to dump the work done from bootstrap shims
95    #[arg(global = true, long)]
96    pub dump_bootstrap_shims: bool,
97    #[arg(global = true, value_hint = clap::ValueHint::Other, long, value_name = "N")]
98    /// stage to build (indicates compiler to use/test, e.g., stage 0 uses the
99    /// bootstrap compiler, stage 1 the stage 0 rustc artifacts, etc.)
100    pub stage: Option<u32>,
101
102    #[arg(global = true, value_hint = clap::ValueHint::Other, long, value_name = "N")]
103    /// stage(s) to keep without recompiling
104    /// (pass multiple times to keep e.g., both stages 0 and 1)
105    pub keep_stage: Vec<u32>,
106    #[arg(global = true, value_hint = clap::ValueHint::Other, long, value_name = "N")]
107    /// stage(s) of the standard library to keep without recompiling
108    /// (pass multiple times to keep e.g., both stages 0 and 1)
109    pub keep_stage_std: Vec<u32>,
110    #[arg(global = true, long, value_hint = clap::ValueHint::DirPath, value_name = "DIR")]
111    /// path to the root of the rust checkout
112    pub src: Option<PathBuf>,
113
114    #[arg(
115        global = true,
116        short,
117        long,
118        value_hint = clap::ValueHint::Other,
119        value_name = "JOBS"
120    )]
121    /// number of jobs to run in parallel
122    pub jobs: Option<u32>,
123    // This overrides the deny-warnings configuration option,
124    // which passes -Dwarnings to the compiler invocations.
125    #[arg(global = true, long)]
126    #[arg(value_enum, default_value_t=Warnings::Default, value_name = "deny|warn")]
127    /// if value is deny, will deny warnings
128    /// if value is warn, will emit warnings
129    /// otherwise, use the default configured behaviour
130    pub warnings: Warnings,
131
132    #[arg(global = true, long)]
133    /// use message-format=json
134    pub json_output: bool,
135    #[arg(global = true, long)]
136    /// only build proc-macros and build scripts (for rust-analyzer)
137    pub compile_time_deps: bool,
138
139    #[arg(global = true, long, value_name = "STYLE")]
140    #[arg(value_enum, default_value_t = Color::Auto)]
141    /// whether to use color in cargo and rustc output
142    pub color: Color,
143
144    #[arg(global = true, long)]
145    /// Bootstrap uses this value to decide whether it should bypass locking the build process.
146    /// This is rarely needed (e.g., compiling the std library for different targets in parallel).
147    ///
148    /// Unless you know exactly what you are doing, you probably don't need this.
149    pub bypass_bootstrap_lock: bool,
150
151    /// generate PGO profile with rustc build
152    #[arg(global = true, value_hint = clap::ValueHint::FilePath, long, value_name = "PROFILE")]
153    pub rust_profile_generate: Option<String>,
154    /// use PGO profile for rustc build
155    #[arg(global = true, value_hint = clap::ValueHint::FilePath, long, value_name = "PROFILE")]
156    pub rust_profile_use: Option<String>,
157    /// use PGO profile for LLVM build
158    #[arg(global = true, value_hint = clap::ValueHint::FilePath, long, value_name = "PROFILE")]
159    pub llvm_profile_use: Option<String>,
160    // LLVM doesn't support a custom location for generating profile
161    // information.
162    //
163    // llvm_out/build/profiles/ is the location this writes to.
164    /// generate PGO profile with llvm built for rustc
165    #[arg(global = true, long)]
166    pub llvm_profile_generate: bool,
167    /// Enable BOLT link flags
168    #[arg(global = true, long)]
169    pub enable_bolt_settings: bool,
170    /// Skip stage0 compiler validation
171    #[arg(global = true, long)]
172    pub skip_stage0_validation: bool,
173    /// Additional reproducible artifacts that should be added to the reproducible artifacts archive.
174    #[arg(global = true, long)]
175    pub reproducible_artifact: Vec<String>,
176    #[arg(global = true)]
177    /// paths for the subcommand
178    pub paths: Vec<PathBuf>,
179    /// override options in bootstrap.toml
180    #[arg(global = true, value_hint = clap::ValueHint::Other, long, value_name = "section.option=value")]
181    pub set: Vec<String>,
182    /// arguments passed to subcommands
183    #[arg(global = true, last(true), value_name = "ARGS")]
184    pub free_args: Vec<String>,
185    /// Make bootstrap to behave as it's running on the CI environment or not.
186    #[arg(global = true, long, value_name = "bool")]
187    pub ci: Option<bool>,
188    /// Skip checking the standard library if `rust.download-rustc` isn't available.
189    /// This is mostly for RA as building the stage1 compiler to check the library tree
190    /// on each code change might be too much for some computers.
191    #[arg(global = true, long)]
192    pub skip_std_check_if_no_download_rustc: bool,
193}
194
195impl Flags {
196    /// Check if `<cmd> -h -v` was passed.
197    /// If yes, print the available paths and return `true`.
198    pub fn try_parse_verbose_help(args: &[String]) -> bool {
199        // We need to check for `<cmd> -h -v`, in which case we list the paths
200        #[derive(Parser)]
201        #[command(disable_help_flag(true))]
202        struct HelpVerboseOnly {
203            #[arg(short, long)]
204            help: bool,
205            #[arg(global = true, short, long, action = clap::ArgAction::Count)]
206            pub verbose: u8,
207            #[arg(value_enum)]
208            cmd: Kind,
209        }
210        if let Ok(HelpVerboseOnly { help: true, verbose: 1.., cmd: subcommand }) =
211            HelpVerboseOnly::try_parse_from(normalize_args(args))
212        {
213            println!("NOTE: updating submodules before printing available paths");
214            let flags = Self::parse(&[String::from("build")]);
215            let config = Config::parse(flags);
216            let build = Build::new(config);
217            let paths = Builder::get_help(&build, subcommand);
218            if let Some(s) = paths {
219                println!("{s}");
220            } else {
221                panic!("No paths available for subcommand `{}`", subcommand.as_str());
222            }
223            true
224        } else {
225            false
226        }
227    }
228
229    #[cfg_attr(
230        feature = "tracing",
231        instrument(level = "trace", name = "Flags::parse", skip_all, fields(args = ?args))
232    )]
233    pub fn parse(args: &[String]) -> Self {
234        Flags::parse_from(normalize_args(args))
235    }
236}
237
238fn normalize_args(args: &[String]) -> Vec<String> {
239    let first = String::from("x.py");
240    let it = std::iter::once(first).chain(args.iter().cloned());
241    it.collect()
242}
243
244#[derive(Debug, Clone, clap::Subcommand)]
245pub enum Subcommand {
246    #[command(aliases = ["b"], long_about = "\n
247    Arguments:
248        This subcommand accepts a number of paths to directories to the crates
249        and/or artifacts to compile. For example, for a quick build of a usable
250        compiler:
251            ./x.py build --stage 1 library/std
252        This will build a compiler and standard library from the local source code.
253        Once this is done, build/$ARCH/stage1 contains a usable compiler.
254        If no arguments are passed then the default artifacts for that stage are
255        compiled. For example:
256            ./x.py build --stage 0
257            ./x.py build ")]
258    /// Compile either the compiler or libraries
259    Build {
260        #[arg(long)]
261        /// Pass `--timings` to Cargo to get crate build timings
262        timings: bool,
263    },
264    #[command(aliases = ["c"], long_about = "\n
265    Arguments:
266        This subcommand accepts a number of paths to directories to the crates
267        and/or artifacts to compile. For example:
268            ./x.py check library/std
269        If no arguments are passed then many artifacts are checked.")]
270    /// Compile either the compiler or libraries, using cargo check
271    Check {
272        #[arg(long)]
273        /// Check all targets
274        all_targets: bool,
275        #[arg(long)]
276        /// Pass `--timings` to Cargo to get crate build timings
277        timings: bool,
278    },
279    /// Run Clippy (uses rustup/cargo-installed clippy binary)
280    #[command(long_about = "\n
281    Arguments:
282        This subcommand accepts a number of paths to directories to the crates
283        and/or artifacts to run clippy against. For example:
284            ./x.py clippy library/core
285            ./x.py clippy library/core library/proc_macro")]
286    Clippy {
287        #[arg(long)]
288        fix: bool,
289        #[arg(long, requires = "fix")]
290        allow_dirty: bool,
291        #[arg(long, requires = "fix")]
292        allow_staged: bool,
293        /// clippy lints to allow
294        #[arg(global = true, short = 'A', action = clap::ArgAction::Append, value_name = "LINT")]
295        allow: Vec<String>,
296        /// clippy lints to deny
297        #[arg(global = true, short = 'D', action = clap::ArgAction::Append, value_name = "LINT")]
298        deny: Vec<String>,
299        /// clippy lints to warn on
300        #[arg(global = true, short = 'W', action = clap::ArgAction::Append, value_name = "LINT")]
301        warn: Vec<String>,
302        /// clippy lints to forbid
303        #[arg(global = true, short = 'F', action = clap::ArgAction::Append, value_name = "LINT")]
304        forbid: Vec<String>,
305    },
306    /// Run cargo fix
307    #[command(long_about = "\n
308    Arguments:
309        This subcommand accepts a number of paths to directories to the crates
310        and/or artifacts to run `cargo fix` against. For example:
311            ./x.py fix library/core
312            ./x.py fix library/core library/proc_macro")]
313    Fix,
314    #[command(
315        name = "fmt",
316        long_about = "\n
317    Arguments:
318        This subcommand optionally accepts a `--check` flag which succeeds if
319        formatting is correct and fails if it is not. For example:
320            ./x.py fmt
321            ./x.py fmt --check"
322    )]
323    /// Run rustfmt
324    Format {
325        /// check formatting instead of applying
326        #[arg(long)]
327        check: bool,
328
329        /// apply to all appropriate files, not just those that have been modified
330        #[arg(long)]
331        all: bool,
332    },
333    #[command(aliases = ["d"], long_about = "\n
334    Arguments:
335        This subcommand accepts a number of paths to directories of documentation
336        to build. For example:
337            ./x.py doc src/doc/book
338            ./x.py doc src/doc/nomicon
339            ./x.py doc src/doc/book library/std
340            ./x.py doc library/std --json
341            ./x.py doc library/std --open
342        If no arguments are passed then everything is documented:
343            ./x.py doc
344            ./x.py doc --stage 1")]
345    /// Build documentation
346    Doc {
347        #[arg(long)]
348        /// open the docs in a browser
349        open: bool,
350        #[arg(long)]
351        /// render the documentation in JSON format in addition to the usual HTML format
352        json: bool,
353    },
354    #[command(aliases = ["t"], long_about = "\n
355    Arguments:
356        This subcommand accepts a number of paths to test directories that
357        should be compiled and run. For example:
358            ./x.py test tests/ui
359            ./x.py test library/std --test-args hash_map
360            ./x.py test library/std --stage 0 --no-doc
361            ./x.py test tests/ui --bless
362            ./x.py test tests/ui --compare-mode next-solver
363        Note that `test tests/* --stage N` does NOT depend on `build compiler/rustc --stage N`;
364        just like `build library/std --stage N` it tests the compiler produced by the previous
365        stage.
366        Execute tool tests with a tool name argument:
367            ./x.py test tidy
368        If no arguments are passed then the complete artifacts for that stage are
369        compiled and tested.
370            ./x.py test
371            ./x.py test --stage 1")]
372    /// Build and run some test suites
373    Test {
374        #[arg(long)]
375        /// run all tests regardless of failure
376        no_fail_fast: bool,
377        #[arg(long, value_name = "ARGS", allow_hyphen_values(true))]
378        /// extra arguments to be passed for the test tool being used
379        /// (e.g. libtest, compiletest or rustdoc)
380        test_args: Vec<String>,
381        /// extra options to pass the compiler when running compiletest tests
382        #[arg(long, value_name = "ARGS", allow_hyphen_values(true))]
383        compiletest_rustc_args: Vec<String>,
384        #[arg(long)]
385        /// do not run doc tests
386        no_doc: bool,
387        #[arg(long)]
388        /// only run doc tests
389        doc: bool,
390        #[arg(long)]
391        /// whether to automatically update stderr/stdout files
392        bless: bool,
393        #[arg(long)]
394        /// comma-separated list of other files types to check (accepts py, py:lint,
395        /// py:fmt, shell, cpp, cpp:fmt, js, js:lint, js:typecheck, spellcheck)
396        ///
397        /// Any argument can be prefixed with "auto:" to only run if
398        /// relevant files are modified (eg. "auto:py").
399        extra_checks: Option<String>,
400        #[arg(long)]
401        /// rerun tests even if the inputs are unchanged
402        force_rerun: bool,
403        #[arg(long)]
404        /// only run tests that result has been changed
405        only_modified: bool,
406        #[arg(long, value_name = "COMPARE MODE")]
407        /// mode describing what file the actual ui output will be compared to
408        compare_mode: Option<String>,
409        #[arg(long, value_name = "check | build | run")]
410        /// force {check,build,run}-pass tests to this mode.
411        pass: Option<String>,
412        #[arg(long, value_name = "auto | always | never")]
413        /// whether to execute run-* tests
414        run: Option<String>,
415        #[arg(long)]
416        /// enable this to generate a Rustfix coverage file, which is saved in
417        /// `/<build_base>/rustfix_missing_coverage.txt`
418        rustfix_coverage: bool,
419        #[arg(long)]
420        /// don't capture stdout/stderr of tests
421        no_capture: bool,
422        #[arg(long)]
423        /// Use a different codegen backend when running tests.
424        test_codegen_backend: Option<CodegenBackendKind>,
425    },
426    /// Build and run some test suites *in Miri*
427    Miri {
428        #[arg(long)]
429        /// run all tests regardless of failure
430        no_fail_fast: bool,
431        #[arg(long, value_name = "ARGS", allow_hyphen_values(true))]
432        /// extra arguments to be passed for the test tool being used
433        /// (e.g. libtest, compiletest or rustdoc)
434        test_args: Vec<String>,
435        #[arg(long)]
436        /// do not run doc tests
437        no_doc: bool,
438        #[arg(long)]
439        /// only run doc tests
440        doc: bool,
441    },
442    /// Build and run some benchmarks
443    Bench {
444        #[arg(long, allow_hyphen_values(true))]
445        test_args: Vec<String>,
446    },
447    /// Clean out build directories
448    Clean {
449        #[arg(long)]
450        /// Clean the entire build directory (not used by default)
451        all: bool,
452        #[arg(long, value_name = "N")]
453        /// Clean a specific stage without touching other artifacts. By default, every stage is cleaned if this option is not used.
454        stage: Option<u32>,
455    },
456    /// Build distribution artifacts
457    Dist,
458    /// Install distribution artifacts
459    Install,
460    #[command(aliases = ["r"], long_about = "\n
461    Arguments:
462        This subcommand accepts a number of paths to tools to build and run. For
463        example:
464            ./x.py run src/tools/bump-stage0
465        At least a tool needs to be called.")]
466    /// Run tools contained in this repository
467    Run {
468        /// arguments for the tool
469        #[arg(long, allow_hyphen_values(true))]
470        args: Vec<String>,
471    },
472    /// Set up the environment for development
473    #[command(long_about = format!(
474        "\n
475x.py setup creates a `bootstrap.toml` which changes the defaults for x.py itself,
476as well as setting up a git pre-push hook, VS Code config and toolchain link.
477Arguments:
478    This subcommand accepts a 'profile' to use for builds. For example:
479        ./x.py setup library
480    The profile is optional and you will be prompted interactively if it is not given.
481    The following profiles are available:
482{}
483    To only set up the git hook, editor config or toolchain link, you may use
484        ./x.py setup hook
485        ./x.py setup editor
486        ./x.py setup link", Profile::all_for_help("        ").trim_end()))]
487    Setup {
488        /// Either the profile for `bootstrap.toml` or another setup action.
489        /// May be omitted to set up interactively
490        #[arg(value_name = "<PROFILE>|hook|editor|link")]
491        profile: Option<PathBuf>,
492    },
493    /// Vendor dependencies
494    Vendor {
495        /// Additional `Cargo.toml` to sync and vendor
496        #[arg(long)]
497        sync: Vec<PathBuf>,
498        /// Always include version in subdir name
499        #[arg(long)]
500        versioned_dirs: bool,
501    },
502    /// Perform profiling and benchmarking of the compiler using `rustc-perf`.
503    Perf(PerfArgs),
504}
505
506impl Default for Subcommand {
507    fn default() -> Self {
508        Subcommand::Build { timings: false }
509    }
510}
511
512impl Subcommand {
513    pub fn kind(&self) -> Kind {
514        match self {
515            Subcommand::Bench { .. } => Kind::Bench,
516            Subcommand::Build { .. } => Kind::Build,
517            Subcommand::Check { .. } => Kind::Check,
518            Subcommand::Clippy { .. } => Kind::Clippy,
519            Subcommand::Doc { .. } => Kind::Doc,
520            Subcommand::Fix => Kind::Fix,
521            Subcommand::Format { .. } => Kind::Format,
522            Subcommand::Test { .. } => Kind::Test,
523            Subcommand::Miri { .. } => Kind::Miri,
524            Subcommand::Clean { .. } => Kind::Clean,
525            Subcommand::Dist => Kind::Dist,
526            Subcommand::Install => Kind::Install,
527            Subcommand::Run { .. } => Kind::Run,
528            Subcommand::Setup { .. } => Kind::Setup,
529            Subcommand::Vendor { .. } => Kind::Vendor,
530            Subcommand::Perf { .. } => Kind::Perf,
531        }
532    }
533
534    pub fn compiletest_rustc_args(&self) -> Vec<&str> {
535        match *self {
536            Subcommand::Test { ref compiletest_rustc_args, .. } => {
537                compiletest_rustc_args.iter().flat_map(|s| s.split_whitespace()).collect()
538            }
539            _ => vec![],
540        }
541    }
542
543    pub fn fail_fast(&self) -> bool {
544        match *self {
545            Subcommand::Test { no_fail_fast, .. } | Subcommand::Miri { no_fail_fast, .. } => {
546                !no_fail_fast
547            }
548            _ => false,
549        }
550    }
551
552    pub fn doc_tests(&self) -> DocTests {
553        match *self {
554            Subcommand::Test { doc, no_doc, .. } | Subcommand::Miri { no_doc, doc, .. } => {
555                if doc {
556                    DocTests::Only
557                } else if no_doc {
558                    DocTests::No
559                } else {
560                    DocTests::Yes
561                }
562            }
563            _ => DocTests::Yes,
564        }
565    }
566
567    pub fn bless(&self) -> bool {
568        match *self {
569            Subcommand::Test { bless, .. } => bless,
570            _ => false,
571        }
572    }
573
574    pub fn extra_checks(&self) -> Option<&str> {
575        match *self {
576            Subcommand::Test { ref extra_checks, .. } => extra_checks.as_ref().map(String::as_str),
577            _ => None,
578        }
579    }
580
581    pub fn only_modified(&self) -> bool {
582        match *self {
583            Subcommand::Test { only_modified, .. } => only_modified,
584            _ => false,
585        }
586    }
587
588    pub fn force_rerun(&self) -> bool {
589        match *self {
590            Subcommand::Test { force_rerun, .. } => force_rerun,
591            _ => false,
592        }
593    }
594
595    pub fn no_capture(&self) -> bool {
596        match *self {
597            Subcommand::Test { no_capture, .. } => no_capture,
598            _ => false,
599        }
600    }
601
602    pub fn rustfix_coverage(&self) -> bool {
603        match *self {
604            Subcommand::Test { rustfix_coverage, .. } => rustfix_coverage,
605            _ => false,
606        }
607    }
608
609    pub fn compare_mode(&self) -> Option<&str> {
610        match *self {
611            Subcommand::Test { ref compare_mode, .. } => compare_mode.as_ref().map(|s| &s[..]),
612            _ => None,
613        }
614    }
615
616    pub fn pass(&self) -> Option<&str> {
617        match *self {
618            Subcommand::Test { ref pass, .. } => pass.as_ref().map(|s| &s[..]),
619            _ => None,
620        }
621    }
622
623    pub fn run(&self) -> Option<&str> {
624        match *self {
625            Subcommand::Test { ref run, .. } => run.as_ref().map(|s| &s[..]),
626            _ => None,
627        }
628    }
629
630    pub fn open(&self) -> bool {
631        match *self {
632            Subcommand::Doc { open, .. } => open,
633            _ => false,
634        }
635    }
636
637    pub fn json(&self) -> bool {
638        match *self {
639            Subcommand::Doc { json, .. } => json,
640            _ => false,
641        }
642    }
643
644    pub fn timings(&self) -> bool {
645        match *self {
646            Subcommand::Build { timings, .. } | Subcommand::Check { timings, .. } => timings,
647            _ => false,
648        }
649    }
650
651    pub fn vendor_versioned_dirs(&self) -> bool {
652        match *self {
653            Subcommand::Vendor { versioned_dirs, .. } => versioned_dirs,
654            _ => false,
655        }
656    }
657
658    pub fn vendor_sync_args(&self) -> Vec<PathBuf> {
659        match self {
660            Subcommand::Vendor { sync, .. } => sync.clone(),
661            _ => vec![],
662        }
663    }
664
665    pub fn test_codegen_backend(&self) -> Option<&CodegenBackendKind> {
666        match self {
667            Subcommand::Test { test_codegen_backend, .. } => test_codegen_backend.as_ref(),
668            _ => None,
669        }
670    }
671}
672
673/// Returns the shell completion for a given shell, if the result differs from the current
674/// content of `path`. If `path` does not exist, always returns `Some`.
675pub fn get_completion(shell: &dyn Generator, path: &Path) -> Option<String> {
676    let mut cmd = Flags::command();
677    let current = if !path.exists() {
678        String::new()
679    } else {
680        std::fs::read_to_string(path).unwrap_or_else(|_| {
681            eprintln!("couldn't read {}", path.display());
682            crate::exit!(1)
683        })
684    };
685    let mut buf = Vec::new();
686    let (bin_name, _) = path
687        .file_name()
688        .expect("path should be a regular file")
689        .to_str()
690        .expect("file name should be UTF-8")
691        .rsplit_once('.')
692        .expect("file name should have an extension");
693
694    // We sort of replicate `clap_complete::generate` here, because we want to call it with
695    // `&dyn Generator`, but that function requires `G: Generator` instead.
696    cmd.set_bin_name(bin_name);
697    cmd.build();
698    shell.generate(&cmd, &mut buf);
699    if buf == current.as_bytes() {
700        return None;
701    }
702    Some(String::from_utf8(buf).expect("completion script should be UTF-8"))
703}
bootstrap/core/config/flags.rs

bootstrap/core/config/
flags.rs
