src/bootstrap/config.rs

   1 //! Serialized configuration of a build.
   2 //!
   3 //! This module implements parsing `config.toml` configuration files to tweak
   4 //! how the build runs.
   5
   6 use std::cmp;
   7 use std::collections::{HashMap, HashSet};
   8 use std::env;
   9 use std::ffi::OsString;
  10 use std::fmt;
  11 use std::fs;
  12 use std::path::{Path, PathBuf};
  13 use std::str::FromStr;
  14
  15 use crate::cache::{Interned, INTERNER};
  16 use crate::channel::GitInfo;
  17 pub use crate::flags::Subcommand;
  18 use crate::flags::{Color, Flags};
  19 use crate::util::exe;
  20 use build_helper::t;
  21 use serde::Deserialize;
  22
  23 macro_rules! check_ci_llvm {
  24     ($name:expr) => {
  25         assert!(
  26             $name.is_none(),
  27             "setting {} is incompatible with download-ci-llvm.",
  28             stringify!($name)
  29         );
  30     };
  31 }
  32
  33 /// Global configuration for the entire build and/or bootstrap.
  34 ///
  35 /// This structure is derived from a combination of both `config.toml` and
  36 /// `config.mk`. As of the time of this writing it's unlikely that `config.toml`
  37 /// is used all that much, so this is primarily filled out by `config.mk` which
  38 /// is generated from `./configure`.
  39 ///
  40 /// Note that this structure is not decoded directly into, but rather it is
  41 /// filled out from the decoded forms of the structs below. For documentation
  42 /// each field, see the corresponding fields in
  43 /// `config.toml.example`.
  44 #[derive(Default)]
  45 pub struct Config {
  46     pub changelog_seen: Option<usize>,
  47     pub ccache: Option<String>,
  48     /// Call Build::ninja() instead of this.
  49     pub ninja_in_file: bool,
  50     pub verbose: usize,
  51     pub submodules: Option<bool>,
  52     pub fast_submodules: bool,
  53     pub compiler_docs: bool,
  54     pub docs_minification: bool,
  55     pub docs: bool,
  56     pub locked_deps: bool,
  57     pub vendor: bool,
  58     pub target_config: HashMap<TargetSelection, Target>,
  59     pub full_bootstrap: bool,
  60     pub extended: bool,
  61     pub tools: Option<HashSet<String>>,
  62     pub sanitizers: bool,
  63     pub profiler: bool,
  64     pub ignore_git: bool,
  65     pub exclude: Vec<PathBuf>,
  66     pub include_default_paths: bool,
  67     pub rustc_error_format: Option<String>,
  68     pub json_output: bool,
  69     pub test_compare_mode: bool,
  70     pub llvm_libunwind: LlvmLibunwind,
  71     pub color: Color,
  72
  73     pub on_fail: Option<String>,
  74     pub stage: u32,
  75     pub keep_stage: Vec<u32>,
  76     pub keep_stage_std: Vec<u32>,
  77     pub src: PathBuf,
  78     // defaults to `config.toml`
  79     pub config: PathBuf,
  80     pub jobs: Option<u32>,
  81     pub cmd: Subcommand,
  82     pub incremental: bool,
  83     pub dry_run: bool,
  84     pub download_rustc: bool,
  85
  86     pub deny_warnings: bool,
  87     pub backtrace_on_ice: bool,
  88
  89     // llvm codegen options
  90     pub llvm_skip_rebuild: bool,
  91     pub llvm_assertions: bool,
  92     pub llvm_tests: bool,
  93     pub llvm_plugins: bool,
  94     pub llvm_optimize: bool,
  95     pub llvm_thin_lto: bool,
  96     pub llvm_release_debuginfo: bool,
  97     pub llvm_version_check: bool,
  98     pub llvm_static_stdcpp: bool,
  99     pub llvm_link_shared: bool,
 100     pub llvm_clang_cl: Option<String>,
 101     pub llvm_targets: Option<String>,
 102     pub llvm_experimental_targets: Option<String>,
 103     pub llvm_link_jobs: Option<u32>,
 104     pub llvm_version_suffix: Option<String>,
 105     pub llvm_use_linker: Option<String>,
 106     pub llvm_allow_old_toolchain: bool,
 107     pub llvm_polly: bool,
 108     pub llvm_clang: bool,
 109     pub llvm_from_ci: bool,
 110
 111     pub use_lld: bool,
 112     pub lld_enabled: bool,
 113     pub llvm_tools_enabled: bool,
 114
 115     pub llvm_cflags: Option<String>,
 116     pub llvm_cxxflags: Option<String>,
 117     pub llvm_ldflags: Option<String>,
 118     pub llvm_use_libcxx: bool,
 119
 120     // rust codegen options
 121     pub rust_optimize: bool,
 122     pub rust_codegen_units: Option<u32>,
 123     pub rust_codegen_units_std: Option<u32>,
 124     pub rust_debug_assertions: bool,
 125     pub rust_debug_assertions_std: bool,
 126     pub rust_overflow_checks: bool,
 127     pub rust_overflow_checks_std: bool,
 128     pub rust_debug_logging: bool,
 129     pub rust_debuginfo_level_rustc: u32,
 130     pub rust_debuginfo_level_std: u32,
 131     pub rust_debuginfo_level_tools: u32,
 132     pub rust_debuginfo_level_tests: u32,
 133     pub rust_run_dsymutil: bool,
 134     pub rust_rpath: bool,
 135     pub rustc_parallel: bool,
 136     pub rustc_default_linker: Option<String>,
 137     pub rust_optimize_tests: bool,
 138     pub rust_dist_src: bool,
 139     pub rust_codegen_backends: Vec<Interned<String>>,
 140     pub rust_verify_llvm_ir: bool,
 141     pub rust_thin_lto_import_instr_limit: Option<u32>,
 142     pub rust_remap_debuginfo: bool,
 143     pub rust_new_symbol_mangling: Option<bool>,
 144     pub rust_profile_use: Option<String>,
 145     pub rust_profile_generate: Option<String>,
 146     pub llvm_profile_use: Option<String>,
 147     pub llvm_profile_generate: bool,
 148
 149     pub build: TargetSelection,
 150     pub hosts: Vec<TargetSelection>,
 151     pub targets: Vec<TargetSelection>,
 152     pub local_rebuild: bool,
 153     pub jemalloc: bool,
 154     pub control_flow_guard: bool,
 155
 156     // dist misc
 157     pub dist_sign_folder: Option<PathBuf>,
 158     pub dist_upload_addr: Option<String>,
 159     pub dist_compression_formats: Option<Vec<String>>,
 160
 161     // libstd features
 162     pub backtrace: bool, // support for RUST_BACKTRACE
 163
 164     // misc
 165     pub low_priority: bool,
 166     pub channel: String,
 167     pub description: Option<String>,
 168     pub verbose_tests: bool,
 169     pub save_toolstates: Option<PathBuf>,
 170     pub print_step_timings: bool,
 171     pub print_step_rusage: bool,
 172     pub missing_tools: bool,
 173
 174     // Fallback musl-root for all targets
 175     pub musl_root: Option<PathBuf>,
 176     pub prefix: Option<PathBuf>,
 177     pub sysconfdir: Option<PathBuf>,
 178     pub datadir: Option<PathBuf>,
 179     pub docdir: Option<PathBuf>,
 180     pub bindir: PathBuf,
 181     pub libdir: Option<PathBuf>,
 182     pub mandir: Option<PathBuf>,
 183     pub codegen_tests: bool,
 184     pub nodejs: Option<PathBuf>,
 185     pub npm: Option<PathBuf>,
 186     pub gdb: Option<PathBuf>,
 187     pub python: Option<PathBuf>,
 188     pub cargo_native_static: bool,
 189     pub configure_args: Vec<String>,
 190
 191     // These are either the stage0 downloaded binaries or the locally installed ones.
 192     pub initial_cargo: PathBuf,
 193     pub initial_rustc: PathBuf,
 194     pub initial_rustfmt: Option<PathBuf>,
 195     pub out: PathBuf,
 196 }
 197
 198 #[derive(Debug, Clone, Copy, PartialEq)]
 199 pub enum LlvmLibunwind {
 200     No,
 201     InTree,
 202     System,
 203 }
 204
 205 impl Default for LlvmLibunwind {
 206     fn default() -> Self {
 207         Self::No
 208     }
 209 }
 210
 211 impl FromStr for LlvmLibunwind {
 212     type Err = String;
 213
 214     fn from_str(value: &str) -> Result<Self, Self::Err> {
 215         match value {
 216             "no" => Ok(Self::No),
 217             "in-tree" => Ok(Self::InTree),
 218             "system" => Ok(Self::System),
 219             invalid => Err(format!("Invalid value '{}' for rust.llvm-libunwind config.", invalid)),
 220         }
 221     }
 222 }
 223
 224 #[derive(Debug, Copy, Clone, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 225 pub struct TargetSelection {
 226     pub triple: Interned<String>,
 227     file: Option<Interned<String>>,
 228 }
 229
 230 impl TargetSelection {
 231     pub fn from_user(selection: &str) -> Self {
 232         let path = Path::new(selection);
 233
 234         let (triple, file) = if path.exists() {
 235             let triple = path
 236                 .file_stem()
 237                 .expect("Target specification file has no file stem")
 238                 .to_str()
 239                 .expect("Target specification file stem is not UTF-8");
 240
 241             (triple, Some(selection))
 242         } else {
 243             (selection, None)
 244         };
 245
 246         let triple = INTERNER.intern_str(triple);
 247         let file = file.map(|f| INTERNER.intern_str(f));
 248
 249         Self { triple, file }
 250     }
 251
 252     pub fn rustc_target_arg(&self) -> &str {
 253         self.file.as_ref().unwrap_or(&self.triple)
 254     }
 255
 256     pub fn contains(&self, needle: &str) -> bool {
 257         self.triple.contains(needle)
 258     }
 259
 260     pub fn starts_with(&self, needle: &str) -> bool {
 261         self.triple.starts_with(needle)
 262     }
 263
 264     pub fn ends_with(&self, needle: &str) -> bool {
 265         self.triple.ends_with(needle)
 266     }
 267 }
 268
 269 impl fmt::Display for TargetSelection {
 270     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 271         write!(f, "{}", self.triple)?;
 272         if let Some(file) = self.file {
 273             write!(f, "({})", file)?;
 274         }
 275         Ok(())
 276     }
 277 }
 278
 279 impl PartialEq<&str> for TargetSelection {
 280     fn eq(&self, other: &&str) -> bool {
 281         self.triple == *other
 282     }
 283 }
 284
 285 /// Per-target configuration stored in the global configuration structure.
 286 #[derive(Default)]
 287 pub struct Target {
 288     /// Some(path to llvm-config) if using an external LLVM.
 289     pub llvm_config: Option<PathBuf>,
 290     /// Some(path to FileCheck) if one was specified.
 291     pub llvm_filecheck: Option<PathBuf>,
 292     pub cc: Option<PathBuf>,
 293     pub cxx: Option<PathBuf>,
 294     pub ar: Option<PathBuf>,
 295     pub ranlib: Option<PathBuf>,
 296     pub default_linker: Option<PathBuf>,
 297     pub linker: Option<PathBuf>,
 298     pub ndk: Option<PathBuf>,
 299     pub sanitizers: Option<bool>,
 300     pub profiler: Option<bool>,
 301     pub crt_static: Option<bool>,
 302     pub musl_root: Option<PathBuf>,
 303     pub musl_libdir: Option<PathBuf>,
 304     pub wasi_root: Option<PathBuf>,
 305     pub qemu_rootfs: Option<PathBuf>,
 306     pub no_std: bool,
 307 }
 308
 309 impl Target {
 310     pub fn from_triple(triple: &str) -> Self {
 311         let mut target: Self = Default::default();
 312         if triple.contains("-none") || triple.contains("nvptx") {
 313             target.no_std = true;
 314         }
 315         target
 316     }
 317 }
 318 /// Structure of the `config.toml` file that configuration is read from.
 319 ///
 320 /// This structure uses `Decodable` to automatically decode a TOML configuration
 321 /// file into this format, and then this is traversed and written into the above
 322 /// `Config` structure.
 323 #[derive(Deserialize, Default)]
 324 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 325 struct TomlConfig {
 326     changelog_seen: Option<usize>,
 327     build: Option<Build>,
 328     install: Option<Install>,
 329     llvm: Option<Llvm>,
 330     rust: Option<Rust>,
 331     target: Option<HashMap<String, TomlTarget>>,
 332     dist: Option<Dist>,
 333     profile: Option<String>,
 334 }
 335
 336 trait Merge {
 337     fn merge(&mut self, other: Self);
 338 }
 339
 340 impl Merge for TomlConfig {
 341     fn merge(
 342         &mut self,
 343         TomlConfig { build, install, llvm, rust, dist, target, profile: _, changelog_seen: _ }: Self,
 344     ) {
 345         fn do_merge<T: Merge>(x: &mut Option<T>, y: Option<T>) {
 346             if let Some(new) = y {
 347                 if let Some(original) = x {
 348                     original.merge(new);
 349                 } else {
 350                     *x = Some(new);
 351                 }
 352             }
 353         }
 354         do_merge(&mut self.build, build);
 355         do_merge(&mut self.install, install);
 356         do_merge(&mut self.llvm, llvm);
 357         do_merge(&mut self.rust, rust);
 358         do_merge(&mut self.dist, dist);
 359         assert!(target.is_none(), "merging target-specific config is not currently supported");
 360     }
 361 }
 362
 363 // We are using a decl macro instead of a derive proc macro here to reduce the compile time of
 364 // rustbuild.
 365 macro_rules! derive_merge {
 366     ($(#[$attr:meta])* struct $name:ident {
 367         $($field:ident: $field_ty:ty,)*
 368     }) => {
 369         $(#[$attr])*
 370         struct $name {
 371             $($field: $field_ty,)*
 372         }
 373
 374         impl Merge for $name {
 375             fn merge(&mut self, other: Self) {
 376                 $(
 377                     if !self.$field.is_some() {
 378                         self.$field = other.$field;
 379                     }
 380                 )*
 381             }
 382         }
 383     }
 384 }
 385
 386 derive_merge! {
 387     /// TOML representation of various global build decisions.
 388     #[derive(Deserialize, Default, Clone)]
 389     #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 390     struct Build {
 391         build: Option<String>,
 392         host: Option<Vec<String>>,
 393         target: Option<Vec<String>>,
 394         // This is ignored, the rust code always gets the build directory from the `BUILD_DIR` env variable
 395         build_dir: Option<String>,
 396         cargo: Option<String>,
 397         rustc: Option<String>,
 398         rustfmt: Option<PathBuf>,
 399         docs: Option<bool>,
 400         compiler_docs: Option<bool>,
 401         docs_minification: Option<bool>,
 402         submodules: Option<bool>,
 403         fast_submodules: Option<bool>,
 404         gdb: Option<String>,
 405         nodejs: Option<String>,
 406         npm: Option<String>,
 407         python: Option<String>,
 408         locked_deps: Option<bool>,
 409         vendor: Option<bool>,
 410         full_bootstrap: Option<bool>,
 411         extended: Option<bool>,
 412         tools: Option<HashSet<String>>,
 413         verbose: Option<usize>,
 414         sanitizers: Option<bool>,
 415         profiler: Option<bool>,
 416         cargo_native_static: Option<bool>,
 417         low_priority: Option<bool>,
 418         configure_args: Option<Vec<String>>,
 419         local_rebuild: Option<bool>,
 420         print_step_timings: Option<bool>,
 421         print_step_rusage: Option<bool>,
 422         check_stage: Option<u32>,
 423         doc_stage: Option<u32>,
 424         build_stage: Option<u32>,
 425         test_stage: Option<u32>,
 426         install_stage: Option<u32>,
 427         dist_stage: Option<u32>,
 428         bench_stage: Option<u32>,
 429         patch_binaries_for_nix: Option<bool>,
 430     }
 431 }
 432
 433 derive_merge! {
 434     /// TOML representation of various global install decisions.
 435     #[derive(Deserialize, Default, Clone)]
 436     #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 437     struct Install {
 438         prefix: Option<String>,
 439         sysconfdir: Option<String>,
 440         docdir: Option<String>,
 441         bindir: Option<String>,
 442         libdir: Option<String>,
 443         mandir: Option<String>,
 444         datadir: Option<String>,
 445     }
 446 }
 447
 448 derive_merge! {
 449     /// TOML representation of how the LLVM build is configured.
 450     #[derive(Deserialize, Default)]
 451     #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 452     struct Llvm {
 453         skip_rebuild: Option<bool>,
 454         optimize: Option<bool>,
 455         thin_lto: Option<bool>,
 456         release_debuginfo: Option<bool>,
 457         assertions: Option<bool>,
 458         tests: Option<bool>,
 459         plugins: Option<bool>,
 460         ccache: Option<StringOrBool>,
 461         version_check: Option<bool>,
 462         static_libstdcpp: Option<bool>,
 463         ninja: Option<bool>,
 464         targets: Option<String>,
 465         experimental_targets: Option<String>,
 466         link_jobs: Option<u32>,
 467         link_shared: Option<bool>,
 468         version_suffix: Option<String>,
 469         clang_cl: Option<String>,
 470         cflags: Option<String>,
 471         cxxflags: Option<String>,
 472         ldflags: Option<String>,
 473         use_libcxx: Option<bool>,
 474         use_linker: Option<String>,
 475         allow_old_toolchain: Option<bool>,
 476         polly: Option<bool>,
 477         clang: Option<bool>,
 478         download_ci_llvm: Option<StringOrBool>,
 479     }
 480 }
 481
 482 derive_merge! {
 483     #[derive(Deserialize, Default, Clone)]
 484     #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 485     struct Dist {
 486         sign_folder: Option<String>,
 487         gpg_password_file: Option<String>,
 488         upload_addr: Option<String>,
 489         src_tarball: Option<bool>,
 490         missing_tools: Option<bool>,
 491         compression_formats: Option<Vec<String>>,
 492     }
 493 }
 494
 495 #[derive(Deserialize)]
 496 #[serde(untagged)]
 497 enum StringOrBool {
 498     String(String),
 499     Bool(bool),
 500 }
 501
 502 impl Default for StringOrBool {
 503     fn default() -> StringOrBool {
 504         StringOrBool::Bool(false)
 505     }
 506 }
 507
 508 derive_merge! {
 509     /// TOML representation of how the Rust build is configured.
 510     #[derive(Deserialize, Default)]
 511     #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 512     struct Rust {
 513         optimize: Option<bool>,
 514         debug: Option<bool>,
 515         codegen_units: Option<u32>,
 516         codegen_units_std: Option<u32>,
 517         debug_assertions: Option<bool>,
 518         debug_assertions_std: Option<bool>,
 519         overflow_checks: Option<bool>,
 520         overflow_checks_std: Option<bool>,
 521         debug_logging: Option<bool>,
 522         debuginfo_level: Option<u32>,
 523         debuginfo_level_rustc: Option<u32>,
 524         debuginfo_level_std: Option<u32>,
 525         debuginfo_level_tools: Option<u32>,
 526         debuginfo_level_tests: Option<u32>,
 527         run_dsymutil: Option<bool>,
 528         backtrace: Option<bool>,
 529         incremental: Option<bool>,
 530         parallel_compiler: Option<bool>,
 531         default_linker: Option<String>,
 532         channel: Option<String>,
 533         description: Option<String>,
 534         musl_root: Option<String>,
 535         rpath: Option<bool>,
 536         verbose_tests: Option<bool>,
 537         optimize_tests: Option<bool>,
 538         codegen_tests: Option<bool>,
 539         ignore_git: Option<bool>,
 540         dist_src: Option<bool>,
 541         save_toolstates: Option<String>,
 542         codegen_backends: Option<Vec<String>>,
 543         lld: Option<bool>,
 544         use_lld: Option<bool>,
 545         llvm_tools: Option<bool>,
 546         deny_warnings: Option<bool>,
 547         backtrace_on_ice: Option<bool>,
 548         verify_llvm_ir: Option<bool>,
 549         thin_lto_import_instr_limit: Option<u32>,
 550         remap_debuginfo: Option<bool>,
 551         jemalloc: Option<bool>,
 552         test_compare_mode: Option<bool>,
 553         llvm_libunwind: Option<String>,
 554         control_flow_guard: Option<bool>,
 555         new_symbol_mangling: Option<bool>,
 556         profile_generate: Option<String>,
 557         profile_use: Option<String>,
 558         // ignored; this is set from an env var set by bootstrap.py
 559         download_rustc: Option<StringOrBool>,
 560     }
 561 }
 562
 563 derive_merge! {
 564     /// TOML representation of how each build target is configured.
 565     #[derive(Deserialize, Default)]
 566     #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 567     struct TomlTarget {
 568         cc: Option<String>,
 569         cxx: Option<String>,
 570         ar: Option<String>,
 571         ranlib: Option<String>,
 572         default_linker: Option<PathBuf>,
 573         linker: Option<String>,
 574         llvm_config: Option<String>,
 575         llvm_filecheck: Option<String>,
 576         android_ndk: Option<String>,
 577         sanitizers: Option<bool>,
 578         profiler: Option<bool>,
 579         crt_static: Option<bool>,
 580         musl_root: Option<String>,
 581         musl_libdir: Option<String>,
 582         wasi_root: Option<String>,
 583         qemu_rootfs: Option<String>,
 584         no_std: Option<bool>,
 585     }
 586 }
 587
 588 impl Config {
 589     fn path_from_python(var_key: &str) -> PathBuf {
 590         match env::var_os(var_key) {
 591             Some(var_val) => Self::normalize_python_path(var_val),
 592             _ => panic!("expected '{}' to be set", var_key),
 593         }
 594     }
 595
 596     /// Normalizes paths from Python slightly. We don't trust paths from Python (#49785).
 597     fn normalize_python_path(path: OsString) -> PathBuf {
 598         Path::new(&path).components().collect()
 599     }
 600
 601     pub fn default_opts() -> Config {
 602         let mut config = Config::default();
 603         config.llvm_optimize = true;
 604         config.ninja_in_file = true;
 605         config.llvm_version_check = true;
 606         config.backtrace = true;
 607         config.rust_optimize = true;
 608         config.rust_optimize_tests = true;
 609         config.submodules = None;
 610         config.fast_submodules = true;
 611         config.docs = true;
 612         config.docs_minification = true;
 613         config.rust_rpath = true;
 614         config.channel = "dev".to_string();
 615         config.codegen_tests = true;
 616         config.rust_dist_src = true;
 617         config.rust_codegen_backends = vec![INTERNER.intern_str("llvm")];
 618         config.deny_warnings = true;
 619         config.bindir = "bin".into();
 620
 621         // set by build.rs
 622         config.build = TargetSelection::from_user(&env!("BUILD_TRIPLE"));
 623         let manifest_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
 624         // Undo `src/bootstrap`
 625         config.src = manifest_dir.parent().unwrap().parent().unwrap().to_owned();
 626         config.out = Config::path_from_python("BUILD_DIR");
 627
 628         config.initial_cargo = PathBuf::from(env!("CARGO"));
 629         config.initial_rustc = PathBuf::from(env!("RUSTC"));
 630
 631         config
 632     }
 633
 634     pub fn parse(args: &[String]) -> Config {
 635         let flags = Flags::parse(&args);
 636
 637         let mut config = Config::default_opts();
 638         config.exclude = flags.exclude;
 639         config.include_default_paths = flags.include_default_paths;
 640         config.rustc_error_format = flags.rustc_error_format;
 641         config.json_output = flags.json_output;
 642         config.on_fail = flags.on_fail;
 643         config.jobs = flags.jobs.map(threads_from_config);
 644         config.cmd = flags.cmd;
 645         config.incremental = flags.incremental;
 646         config.dry_run = flags.dry_run;
 647         config.keep_stage = flags.keep_stage;
 648         config.keep_stage_std = flags.keep_stage_std;
 649         config.color = flags.color;
 650         if let Some(value) = flags.deny_warnings {
 651             config.deny_warnings = value;
 652         }
 653         config.llvm_profile_use = flags.llvm_profile_use;
 654         config.llvm_profile_generate = flags.llvm_profile_generate;
 655
 656         if config.dry_run {
 657             let dir = config.out.join("tmp-dry-run");
 658             t!(fs::create_dir_all(&dir));
 659             config.out = dir;
 660         }
 661
 662         #[cfg(test)]
 663         let get_toml = |_| TomlConfig::default();
 664         #[cfg(not(test))]
 665         let get_toml = |file: &Path| {
 666             use std::process;
 667
 668             let contents = t!(fs::read_to_string(file), "`include` config not found");
 669             match toml::from_str(&contents) {
 670                 Ok(table) => table,
 671                 Err(err) => {
 672                     println!("failed to parse TOML configuration '{}': {}", file.display(), err);
 673                     process::exit(2);
 674                 }
 675             }
 676         };
 677
 678         let mut toml = flags.config.as_deref().map(get_toml).unwrap_or_else(TomlConfig::default);
 679         if let Some(include) = &toml.profile {
 680             let mut include_path = config.src.clone();
 681             include_path.push("src");
 682             include_path.push("bootstrap");
 683             include_path.push("defaults");
 684             include_path.push(format!("config.{}.toml", include));
 685             let included_toml = get_toml(&include_path);
 686             toml.merge(included_toml);
 687         }
 688
 689         config.changelog_seen = toml.changelog_seen;
 690         if let Some(cfg) = flags.config {
 691             config.config = cfg;
 692         }
 693
 694         let build = toml.build.unwrap_or_default();
 695
 696         config.hosts = if let Some(arg_host) = flags.host {
 697             arg_host
 698         } else if let Some(file_host) = build.host {
 699             file_host.iter().map(|h| TargetSelection::from_user(h)).collect()
 700         } else {
 701             vec![config.build]
 702         };
 703         config.targets = if let Some(arg_target) = flags.target {
 704             arg_target
 705         } else if let Some(file_target) = build.target {
 706             file_target.iter().map(|h| TargetSelection::from_user(h)).collect()
 707         } else {
 708             // If target is *not* configured, then default to the host
 709             // toolchains.
 710             config.hosts.clone()
 711         };
 712
 713         config.nodejs = build.nodejs.map(PathBuf::from);
 714         config.npm = build.npm.map(PathBuf::from);
 715         config.gdb = build.gdb.map(PathBuf::from);
 716         config.python = build.python.map(PathBuf::from);
 717         config.submodules = build.submodules;
 718         set(&mut config.low_priority, build.low_priority);
 719         set(&mut config.compiler_docs, build.compiler_docs);
 720         set(&mut config.docs_minification, build.docs_minification);
 721         set(&mut config.docs, build.docs);
 722         set(&mut config.fast_submodules, build.fast_submodules);
 723         set(&mut config.locked_deps, build.locked_deps);
 724         set(&mut config.vendor, build.vendor);
 725         set(&mut config.full_bootstrap, build.full_bootstrap);
 726         set(&mut config.extended, build.extended);
 727         config.tools = build.tools;
 728         if build.rustfmt.is_some() {
 729             config.initial_rustfmt = build.rustfmt;
 730         }
 731         set(&mut config.verbose, build.verbose);
 732         set(&mut config.sanitizers, build.sanitizers);
 733         set(&mut config.profiler, build.profiler);
 734         set(&mut config.cargo_native_static, build.cargo_native_static);
 735         set(&mut config.configure_args, build.configure_args);
 736         set(&mut config.local_rebuild, build.local_rebuild);
 737         set(&mut config.print_step_timings, build.print_step_timings);
 738         set(&mut config.print_step_rusage, build.print_step_rusage);
 739
 740         config.verbose = cmp::max(config.verbose, flags.verbose);
 741
 742         if let Some(install) = toml.install {
 743             config.prefix = install.prefix.map(PathBuf::from);
 744             config.sysconfdir = install.sysconfdir.map(PathBuf::from);
 745             config.datadir = install.datadir.map(PathBuf::from);
 746             config.docdir = install.docdir.map(PathBuf::from);
 747             set(&mut config.bindir, install.bindir.map(PathBuf::from));
 748             config.libdir = install.libdir.map(PathBuf::from);
 749             config.mandir = install.mandir.map(PathBuf::from);
 750         }
 751
 752         // We want the llvm-skip-rebuild flag to take precedence over the
 753         // skip-rebuild config.toml option so we store it separately
 754         // so that we can infer the right value
 755         let mut llvm_skip_rebuild = flags.llvm_skip_rebuild;
 756
 757         // Store off these values as options because if they're not provided
 758         // we'll infer default values for them later
 759         let mut llvm_assertions = None;
 760         let mut llvm_tests = None;
 761         let mut llvm_plugins = None;
 762         let mut debug = None;
 763         let mut debug_assertions = None;
 764         let mut debug_assertions_std = None;
 765         let mut overflow_checks = None;
 766         let mut overflow_checks_std = None;
 767         let mut debug_logging = None;
 768         let mut debuginfo_level = None;
 769         let mut debuginfo_level_rustc = None;
 770         let mut debuginfo_level_std = None;
 771         let mut debuginfo_level_tools = None;
 772         let mut debuginfo_level_tests = None;
 773         let mut optimize = None;
 774         let mut ignore_git = None;
 775
 776         if let Some(llvm) = toml.llvm {
 777             match llvm.ccache {
 778                 Some(StringOrBool::String(ref s)) => config.ccache = Some(s.to_string()),
 779                 Some(StringOrBool::Bool(true)) => {
 780                     config.ccache = Some("ccache".to_string());
 781                 }
 782                 Some(StringOrBool::Bool(false)) | None => {}
 783             }
 784             set(&mut config.ninja_in_file, llvm.ninja);
 785             llvm_assertions = llvm.assertions;
 786             llvm_tests = llvm.tests;
 787             llvm_plugins = llvm.plugins;
 788             llvm_skip_rebuild = llvm_skip_rebuild.or(llvm.skip_rebuild);
 789             set(&mut config.llvm_optimize, llvm.optimize);
 790             set(&mut config.llvm_thin_lto, llvm.thin_lto);
 791             set(&mut config.llvm_release_debuginfo, llvm.release_debuginfo);
 792             set(&mut config.llvm_version_check, llvm.version_check);
 793             set(&mut config.llvm_static_stdcpp, llvm.static_libstdcpp);
 794             set(&mut config.llvm_link_shared, llvm.link_shared);
 795             config.llvm_targets = llvm.targets.clone();
 796             config.llvm_experimental_targets = llvm.experimental_targets.clone();
 797             config.llvm_link_jobs = llvm.link_jobs;
 798             config.llvm_version_suffix = llvm.version_suffix.clone();
 799             config.llvm_clang_cl = llvm.clang_cl.clone();
 800
 801             config.llvm_cflags = llvm.cflags.clone();
 802             config.llvm_cxxflags = llvm.cxxflags.clone();
 803             config.llvm_ldflags = llvm.ldflags.clone();
 804             set(&mut config.llvm_use_libcxx, llvm.use_libcxx);
 805             config.llvm_use_linker = llvm.use_linker.clone();
 806             config.llvm_allow_old_toolchain = llvm.allow_old_toolchain.unwrap_or(false);
 807             config.llvm_polly = llvm.polly.unwrap_or(false);
 808             config.llvm_clang = llvm.clang.unwrap_or(false);
 809             config.llvm_from_ci = match llvm.download_ci_llvm {
 810                 Some(StringOrBool::String(s)) => {
 811                     assert!(s == "if-available", "unknown option `{}` for download-ci-llvm", s);
 812                     // This is currently all tier 1 targets and tier 2 targets with host tools
 813                     // (since others may not have CI artifacts)
 814                     // https://doc.rust-lang.org/rustc/platform-support.html#tier-1
 815                     // FIXME: this is duplicated in bootstrap.py
 816                     let supported_platforms = [
 817                         // tier 1
 818                         "aarch64-unknown-linux-gnu",
 819                         "i686-pc-windows-gnu",
 820                         "i686-pc-windows-msvc",
 821                         "i686-unknown-linux-gnu",
 822                         "x86_64-unknown-linux-gnu",
 823                         "x86_64-apple-darwin",
 824                         "x86_64-pc-windows-gnu",
 825                         "x86_64-pc-windows-msvc",
 826                         // tier 2 with host tools
 827                         "aarch64-apple-darwin",
 828                         "aarch64-pc-windows-msvc",
 829                         "aarch64-unknown-linux-musl",
 830                         "arm-unknown-linux-gnueabi",
 831                         "arm-unknown-linux-gnueabihf",
 832                         "armv7-unknown-linux-gnueabihf",
 833                         "mips-unknown-linux-gnu",
 834                         "mips64-unknown-linux-gnuabi64",
 835                         "mips64el-unknown-linux-gnuabi64",
 836                         "mipsel-unknown-linux-gnu",
 837                         "powerpc-unknown-linux-gnu",
 838                         "powerpc64-unknown-linux-gnu",
 839                         "powerpc64le-unknown-linux-gnu",
 840                         "riscv64gc-unknown-linux-gnu",
 841                         "s390x-unknown-linux-gnu",
 842                         "x86_64-unknown-freebsd",
 843                         "x86_64-unknown-illumos",
 844                         "x86_64-unknown-linux-musl",
 845                         "x86_64-unknown-netbsd",
 846                     ];
 847                     supported_platforms.contains(&&*config.build.triple)
 848                 }
 849                 Some(StringOrBool::Bool(b)) => b,
 850                 None => false,
 851             };
 852
 853             if config.llvm_from_ci {
 854                 // None of the LLVM options, except assertions, are supported
 855                 // when using downloaded LLVM. We could just ignore these but
 856                 // that's potentially confusing, so force them to not be
 857                 // explicitly set. The defaults and CI defaults don't
 858                 // necessarily match but forcing people to match (somewhat
 859                 // arbitrary) CI configuration locally seems bad/hard.
 860                 check_ci_llvm!(llvm.optimize);
 861                 check_ci_llvm!(llvm.thin_lto);
 862                 check_ci_llvm!(llvm.release_debuginfo);
 863                 check_ci_llvm!(llvm.link_shared);
 864                 check_ci_llvm!(llvm.static_libstdcpp);
 865                 check_ci_llvm!(llvm.targets);
 866                 check_ci_llvm!(llvm.experimental_targets);
 867                 check_ci_llvm!(llvm.link_jobs);
 868                 check_ci_llvm!(llvm.clang_cl);
 869                 check_ci_llvm!(llvm.version_suffix);
 870                 check_ci_llvm!(llvm.cflags);
 871                 check_ci_llvm!(llvm.cxxflags);
 872                 check_ci_llvm!(llvm.ldflags);
 873                 check_ci_llvm!(llvm.use_libcxx);
 874                 check_ci_llvm!(llvm.use_linker);
 875                 check_ci_llvm!(llvm.allow_old_toolchain);
 876                 check_ci_llvm!(llvm.polly);
 877                 check_ci_llvm!(llvm.clang);
 878                 check_ci_llvm!(llvm.plugins);
 879
 880                 // CI-built LLVM can be either dynamic or static.
 881                 let ci_llvm = config.out.join(&*config.build.triple).join("ci-llvm");
 882                 config.llvm_link_shared = if config.dry_run {
 883                     // just assume dynamic for now
 884                     true
 885                 } else {
 886                     let link_type = t!(
 887                         std::fs::read_to_string(ci_llvm.join("link-type.txt")),
 888                         format!("CI llvm missing: {}", ci_llvm.display())
 889                     );
 890                     link_type == "dynamic"
 891                 };
 892             }
 893
 894             if config.llvm_thin_lto && llvm.link_shared.is_none() {
 895                 // If we're building with ThinLTO on, by default we want to link
 896                 // to LLVM shared, to avoid re-doing ThinLTO (which happens in
 897                 // the link step) with each stage.
 898                 config.llvm_link_shared = true;
 899             }
 900         }
 901
 902         if let Some(rust) = toml.rust {
 903             debug = rust.debug;
 904             debug_assertions = rust.debug_assertions;
 905             debug_assertions_std = rust.debug_assertions_std;
 906             overflow_checks = rust.overflow_checks;
 907             overflow_checks_std = rust.overflow_checks_std;
 908             debug_logging = rust.debug_logging;
 909             debuginfo_level = rust.debuginfo_level;
 910             debuginfo_level_rustc = rust.debuginfo_level_rustc;
 911             debuginfo_level_std = rust.debuginfo_level_std;
 912             debuginfo_level_tools = rust.debuginfo_level_tools;
 913             debuginfo_level_tests = rust.debuginfo_level_tests;
 914             config.rust_run_dsymutil = rust.run_dsymutil.unwrap_or(false);
 915             optimize = rust.optimize;
 916             ignore_git = rust.ignore_git;
 917             config.rust_new_symbol_mangling = rust.new_symbol_mangling;
 918             set(&mut config.rust_optimize_tests, rust.optimize_tests);
 919             set(&mut config.codegen_tests, rust.codegen_tests);
 920             set(&mut config.rust_rpath, rust.rpath);
 921             set(&mut config.jemalloc, rust.jemalloc);
 922             set(&mut config.test_compare_mode, rust.test_compare_mode);
 923             config.llvm_libunwind = rust
 924                 .llvm_libunwind
 925                 .map(|v| v.parse().expect("failed to parse rust.llvm-libunwind"))
 926                 .unwrap_or_default();
 927             set(&mut config.backtrace, rust.backtrace);
 928             set(&mut config.channel, rust.channel);
 929             config.description = rust.description;
 930             set(&mut config.rust_dist_src, rust.dist_src);
 931             set(&mut config.verbose_tests, rust.verbose_tests);
 932             // in the case "false" is set explicitly, do not overwrite the command line args
 933             if let Some(true) = rust.incremental {
 934                 config.incremental = true;
 935             }
 936             set(&mut config.use_lld, rust.use_lld);
 937             set(&mut config.lld_enabled, rust.lld);
 938             set(&mut config.llvm_tools_enabled, rust.llvm_tools);
 939             config.rustc_parallel = rust.parallel_compiler.unwrap_or(false);
 940             config.rustc_default_linker = rust.default_linker;
 941             config.musl_root = rust.musl_root.map(PathBuf::from);
 942             config.save_toolstates = rust.save_toolstates.map(PathBuf::from);
 943             set(&mut config.deny_warnings, flags.deny_warnings.or(rust.deny_warnings));
 944             set(&mut config.backtrace_on_ice, rust.backtrace_on_ice);
 945             set(&mut config.rust_verify_llvm_ir, rust.verify_llvm_ir);
 946             config.rust_thin_lto_import_instr_limit = rust.thin_lto_import_instr_limit;
 947             set(&mut config.rust_remap_debuginfo, rust.remap_debuginfo);
 948             set(&mut config.control_flow_guard, rust.control_flow_guard);
 949
 950             if let Some(ref backends) = rust.codegen_backends {
 951                 config.rust_codegen_backends =
 952                     backends.iter().map(|s| INTERNER.intern_str(s)).collect();
 953             }
 954
 955             config.rust_codegen_units = rust.codegen_units.map(threads_from_config);
 956             config.rust_codegen_units_std = rust.codegen_units_std.map(threads_from_config);
 957             config.rust_profile_use = flags.rust_profile_use.or(rust.profile_use);
 958             config.rust_profile_generate = flags.rust_profile_generate.or(rust.profile_generate);
 959             config.download_rustc = env::var("BOOTSTRAP_DOWNLOAD_RUSTC").as_deref() == Ok("1");
 960         } else {
 961             config.rust_profile_use = flags.rust_profile_use;
 962             config.rust_profile_generate = flags.rust_profile_generate;
 963         }
 964
 965         if let Some(t) = toml.target {
 966             for (triple, cfg) in t {
 967                 let mut target = Target::from_triple(&triple);
 968
 969                 if let Some(ref s) = cfg.llvm_config {
 970                     target.llvm_config = Some(config.src.join(s));
 971                 }
 972                 if let Some(ref s) = cfg.llvm_filecheck {
 973                     target.llvm_filecheck = Some(config.src.join(s));
 974                 }
 975                 if let Some(ref s) = cfg.android_ndk {
 976                     target.ndk = Some(config.src.join(s));
 977                 }
 978                 if let Some(s) = cfg.no_std {
 979                     target.no_std = s;
 980                 }
 981                 target.cc = cfg.cc.map(PathBuf::from);
 982                 target.cxx = cfg.cxx.map(PathBuf::from);
 983                 target.ar = cfg.ar.map(PathBuf::from);
 984                 target.ranlib = cfg.ranlib.map(PathBuf::from);
 985                 target.linker = cfg.linker.map(PathBuf::from);
 986                 target.crt_static = cfg.crt_static;
 987                 target.musl_root = cfg.musl_root.map(PathBuf::from);
 988                 target.musl_libdir = cfg.musl_libdir.map(PathBuf::from);
 989                 target.wasi_root = cfg.wasi_root.map(PathBuf::from);
 990                 target.qemu_rootfs = cfg.qemu_rootfs.map(PathBuf::from);
 991                 target.sanitizers = cfg.sanitizers;
 992                 target.profiler = cfg.profiler;
 993
 994                 config.target_config.insert(TargetSelection::from_user(&triple), target);
 995             }
 996         }
 997
 998         if config.llvm_from_ci {
 999             let triple = &config.build.triple;
1000             let mut build_target = config
1001                 .target_config
1002                 .entry(config.build)
1003                 .or_insert_with(|| Target::from_triple(&triple));
1004
1005             check_ci_llvm!(build_target.llvm_config);
1006             check_ci_llvm!(build_target.llvm_filecheck);
1007             let ci_llvm_bin = config.out.join(&*config.build.triple).join("ci-llvm/bin");
1008             build_target.llvm_config = Some(ci_llvm_bin.join(exe("llvm-config", config.build)));
1009             build_target.llvm_filecheck = Some(ci_llvm_bin.join(exe("FileCheck", config.build)));
1010         }
1011
1012         if let Some(t) = toml.dist {
1013             config.dist_sign_folder = t.sign_folder.map(PathBuf::from);
1014             config.dist_upload_addr = t.upload_addr;
1015             config.dist_compression_formats = t.compression_formats;
1016             set(&mut config.rust_dist_src, t.src_tarball);
1017             set(&mut config.missing_tools, t.missing_tools);
1018         }
1019
1020         config.initial_rustfmt = config.initial_rustfmt.or_else({
1021             let build = config.build;
1022             let initial_rustc = &config.initial_rustc;
1023
1024             move || {
1025                 // Cargo does not provide a RUSTFMT environment variable, so we
1026                 // synthesize it manually.
1027                 let rustfmt = initial_rustc.with_file_name(exe("rustfmt", build));
1028
1029                 if rustfmt.exists() { Some(rustfmt) } else { None }
1030             }
1031         });
1032
1033         // Now that we've reached the end of our configuration, infer the
1034         // default values for all options that we haven't otherwise stored yet.
1035
1036         config.llvm_skip_rebuild = llvm_skip_rebuild.unwrap_or(false);
1037         config.llvm_assertions = llvm_assertions.unwrap_or(false);
1038         config.llvm_tests = llvm_tests.unwrap_or(false);
1039         config.llvm_plugins = llvm_plugins.unwrap_or(false);
1040         config.rust_optimize = optimize.unwrap_or(true);
1041
1042         let default = debug == Some(true);
1043         config.rust_debug_assertions = debug_assertions.unwrap_or(default);
1044         config.rust_debug_assertions_std =
1045             debug_assertions_std.unwrap_or(config.rust_debug_assertions);
1046         config.rust_overflow_checks = overflow_checks.unwrap_or(default);
1047         config.rust_overflow_checks_std =
1048             overflow_checks_std.unwrap_or(config.rust_overflow_checks);
1049
1050         config.rust_debug_logging = debug_logging.unwrap_or(config.rust_debug_assertions);
1051
1052         let with_defaults = |debuginfo_level_specific: Option<u32>| {
1053             debuginfo_level_specific.or(debuginfo_level).unwrap_or(if debug == Some(true) {
1054                 1
1055             } else {
1056                 0
1057             })
1058         };
1059         config.rust_debuginfo_level_rustc = with_defaults(debuginfo_level_rustc);
1060         config.rust_debuginfo_level_std = with_defaults(debuginfo_level_std);
1061         config.rust_debuginfo_level_tools = with_defaults(debuginfo_level_tools);
1062         config.rust_debuginfo_level_tests = debuginfo_level_tests.unwrap_or(0);
1063
1064         let default = config.channel == "dev";
1065         config.ignore_git = ignore_git.unwrap_or(default);
1066
1067         let download_rustc = config.download_rustc;
1068         // See https://github.com/rust-lang/compiler-team/issues/326
1069         config.stage = match config.cmd {
1070             Subcommand::Check { .. } => flags.stage.or(build.check_stage).unwrap_or(0),
1071             // `download-rustc` only has a speed-up for stage2 builds. Default to stage2 unless explicitly overridden.
1072             Subcommand::Doc { .. } => {
1073                 flags.stage.or(build.doc_stage).unwrap_or(if download_rustc { 2 } else { 0 })
1074             }
1075             Subcommand::Build { .. } => {
1076                 flags.stage.or(build.build_stage).unwrap_or(if download_rustc { 2 } else { 1 })
1077             }
1078             Subcommand::Test { .. } => {
1079                 flags.stage.or(build.test_stage).unwrap_or(if download_rustc { 2 } else { 1 })
1080             }
1081             Subcommand::Bench { .. } => flags.stage.or(build.bench_stage).unwrap_or(2),
1082             Subcommand::Dist { .. } => flags.stage.or(build.dist_stage).unwrap_or(2),
1083             Subcommand::Install { .. } => flags.stage.or(build.install_stage).unwrap_or(2),
1084             // These are all bootstrap tools, which don't depend on the compiler.
1085             // The stage we pass shouldn't matter, but use 0 just in case.
1086             Subcommand::Clean { .. }
1087             | Subcommand::Clippy { .. }
1088             | Subcommand::Fix { .. }
1089             | Subcommand::Run { .. }
1090             | Subcommand::Setup { .. }
1091             | Subcommand::Format { .. } => flags.stage.unwrap_or(0),
1092         };
1093
1094         // CI should always run stage 2 builds, unless it specifically states otherwise
1095         #[cfg(not(test))]
1096         if flags.stage.is_none() && crate::CiEnv::current() != crate::CiEnv::None {
1097             match config.cmd {
1098                 Subcommand::Test { .. }
1099                 | Subcommand::Doc { .. }
1100                 | Subcommand::Build { .. }
1101                 | Subcommand::Bench { .. }
1102                 | Subcommand::Dist { .. }
1103                 | Subcommand::Install { .. } => {
1104                     assert_eq!(
1105                         config.stage, 2,
1106                         "x.py should be run with `--stage 2` on CI, but was run with `--stage {}`",
1107                         config.stage,
1108                     );
1109                 }
1110                 Subcommand::Clean { .. }
1111                 | Subcommand::Check { .. }
1112                 | Subcommand::Clippy { .. }
1113                 | Subcommand::Fix { .. }
1114                 | Subcommand::Run { .. }
1115                 | Subcommand::Setup { .. }
1116                 | Subcommand::Format { .. } => {}
1117             }
1118         }
1119
1120         config
1121     }
1122
1123     /// Try to find the relative path of `bindir`, otherwise return it in full.
1124     pub fn bindir_relative(&self) -> &Path {
1125         let bindir = &self.bindir;
1126         if bindir.is_absolute() {
1127             // Try to make it relative to the prefix.
1128             if let Some(prefix) = &self.prefix {
1129                 if let Ok(stripped) = bindir.strip_prefix(prefix) {
1130                     return stripped;
1131                 }
1132             }
1133         }
1134         bindir
1135     }
1136
1137     /// Try to find the relative path of `libdir`.
1138     pub fn libdir_relative(&self) -> Option<&Path> {
1139         let libdir = self.libdir.as_ref()?;
1140         if libdir.is_relative() {
1141             Some(libdir)
1142         } else {
1143             // Try to make it relative to the prefix.
1144             libdir.strip_prefix(self.prefix.as_ref()?).ok()
1145         }
1146     }
1147
1148     pub fn verbose(&self) -> bool {
1149         self.verbose > 0
1150     }
1151
1152     pub fn sanitizers_enabled(&self, target: TargetSelection) -> bool {
1153         self.target_config.get(&target).map(|t| t.sanitizers).flatten().unwrap_or(self.sanitizers)
1154     }
1155
1156     pub fn any_sanitizers_enabled(&self) -> bool {
1157         self.target_config.values().any(|t| t.sanitizers == Some(true)) || self.sanitizers
1158     }
1159
1160     pub fn profiler_enabled(&self, target: TargetSelection) -> bool {
1161         self.target_config.get(&target).map(|t| t.profiler).flatten().unwrap_or(self.profiler)
1162     }
1163
1164     pub fn any_profiler_enabled(&self) -> bool {
1165         self.target_config.values().any(|t| t.profiler == Some(true)) || self.profiler
1166     }
1167
1168     pub fn llvm_enabled(&self) -> bool {
1169         self.rust_codegen_backends.contains(&INTERNER.intern_str("llvm"))
1170     }
1171
1172     pub fn submodules(&self, rust_info: &GitInfo) -> bool {
1173         self.submodules.unwrap_or(rust_info.is_git())
1174     }
1175 }
1176
1177 fn set<T>(field: &mut T, val: Option<T>) {
1178     if let Some(v) = val {
1179         *field = v;
1180     }
1181 }
1182
1183 fn threads_from_config(v: u32) -> u32 {
1184     match v {
1185         0 => num_cpus::get() as u32,
1186         n => n,
1187     }
1188 }