src/bootstrap/config.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Serialized configuration of a build.
  12 //!
  13 //! This module implements parsing `config.mk` and `config.toml` configuration
  14 //! files to tweak how the build runs.
  15
  16 use std::collections::HashMap;
  17 use std::env;
  18 use std::fs::File;
  19 use std::io::prelude::*;
  20 use std::path::PathBuf;
  21 use std::process;
  22
  23 use num_cpus;
  24 use rustc_serialize::Decodable;
  25 use toml::{Parser, Decoder, Value};
  26 use util::push_exe_path;
  27
  28 /// Global configuration for the entire build and/or bootstrap.
  29 ///
  30 /// This structure is derived from a combination of both `config.toml` and
  31 /// `config.mk`. As of the time of this writing it's unlikely that `config.toml`
  32 /// is used all that much, so this is primarily filled out by `config.mk` which
  33 /// is generated from `./configure`.
  34 ///
  35 /// Note that this structure is not decoded directly into, but rather it is
  36 /// filled out from the decoded forms of the structs below. For documentation
  37 /// each field, see the corresponding fields in
  38 /// `src/bootstrap/config.toml.example`.
  39 #[derive(Default)]
  40 pub struct Config {
  41     pub ccache: Option<String>,
  42     pub ninja: bool,
  43     pub verbose: usize,
  44     pub submodules: bool,
  45     pub compiler_docs: bool,
  46     pub docs: bool,
  47     pub vendor: bool,
  48     pub target_config: HashMap<String, Target>,
  49     pub full_bootstrap: bool,
  50     pub extended: bool,
  51
  52     // llvm codegen options
  53     pub llvm_assertions: bool,
  54     pub llvm_optimize: bool,
  55     pub llvm_release_debuginfo: bool,
  56     pub llvm_version_check: bool,
  57     pub llvm_static_stdcpp: bool,
  58     pub llvm_link_shared: bool,
  59     pub llvm_targets: Option<String>,
  60
  61     // rust codegen options
  62     pub rust_optimize: bool,
  63     pub rust_codegen_units: u32,
  64     pub rust_debug_assertions: bool,
  65     pub rust_debuginfo: bool,
  66     pub rust_debuginfo_lines: bool,
  67     pub rust_debuginfo_only_std: bool,
  68     pub rust_rpath: bool,
  69     pub rustc_default_linker: Option<String>,
  70     pub rustc_default_ar: Option<String>,
  71     pub rust_optimize_tests: bool,
  72     pub rust_debuginfo_tests: bool,
  73
  74     pub build: String,
  75     pub host: Vec<String>,
  76     pub target: Vec<String>,
  77     pub rustc: Option<PathBuf>,
  78     pub cargo: Option<PathBuf>,
  79     pub local_rebuild: bool,
  80
  81     // dist misc
  82     pub dist_sign_folder: Option<PathBuf>,
  83     pub dist_upload_addr: Option<String>,
  84     pub dist_gpg_password_file: Option<PathBuf>,
  85
  86     // libstd features
  87     pub debug_jemalloc: bool,
  88     pub use_jemalloc: bool,
  89     pub backtrace: bool, // support for RUST_BACKTRACE
  90
  91     // misc
  92     pub channel: String,
  93     pub quiet_tests: bool,
  94     // Fallback musl-root for all targets
  95     pub musl_root: Option<PathBuf>,
  96     pub prefix: Option<PathBuf>,
  97     pub docdir: Option<PathBuf>,
  98     pub libdir: Option<PathBuf>,
  99     pub libdir_relative: Option<PathBuf>,
 100     pub mandir: Option<PathBuf>,
 101     pub codegen_tests: bool,
 102     pub nodejs: Option<PathBuf>,
 103     pub gdb: Option<PathBuf>,
 104     pub python: Option<PathBuf>,
 105     pub configure_args: Vec<String>,
 106 }
 107
 108 /// Per-target configuration stored in the global configuration structure.
 109 #[derive(Default)]
 110 pub struct Target {
 111     pub llvm_config: Option<PathBuf>,
 112     pub jemalloc: Option<PathBuf>,
 113     pub cc: Option<PathBuf>,
 114     pub cxx: Option<PathBuf>,
 115     pub ndk: Option<PathBuf>,
 116     pub musl_root: Option<PathBuf>,
 117 }
 118
 119 /// Structure of the `config.toml` file that configuration is read from.
 120 ///
 121 /// This structure uses `Decodable` to automatically decode a TOML configuration
 122 /// file into this format, and then this is traversed and written into the above
 123 /// `Config` structure.
 124 #[derive(RustcDecodable, Default)]
 125 struct TomlConfig {
 126     build: Option<Build>,
 127     install: Option<Install>,
 128     llvm: Option<Llvm>,
 129     rust: Option<Rust>,
 130     target: Option<HashMap<String, TomlTarget>>,
 131     dist: Option<Dist>,
 132 }
 133
 134 /// TOML representation of various global build decisions.
 135 #[derive(RustcDecodable, Default, Clone)]
 136 struct Build {
 137     build: Option<String>,
 138     host: Vec<String>,
 139     target: Vec<String>,
 140     cargo: Option<String>,
 141     rustc: Option<String>,
 142     compiler_docs: Option<bool>,
 143     docs: Option<bool>,
 144     submodules: Option<bool>,
 145     gdb: Option<String>,
 146     vendor: Option<bool>,
 147     nodejs: Option<String>,
 148     python: Option<String>,
 149     full_bootstrap: Option<bool>,
 150     extended: Option<bool>,
 151 }
 152
 153 /// TOML representation of various global install decisions.
 154 #[derive(RustcDecodable, Default, Clone)]
 155 struct Install {
 156     prefix: Option<String>,
 157     mandir: Option<String>,
 158     docdir: Option<String>,
 159     libdir: Option<String>,
 160 }
 161
 162 /// TOML representation of how the LLVM build is configured.
 163 #[derive(RustcDecodable, Default)]
 164 struct Llvm {
 165     ccache: Option<StringOrBool>,
 166     ninja: Option<bool>,
 167     assertions: Option<bool>,
 168     optimize: Option<bool>,
 169     release_debuginfo: Option<bool>,
 170     version_check: Option<bool>,
 171     static_libstdcpp: Option<bool>,
 172     targets: Option<String>,
 173 }
 174
 175 #[derive(RustcDecodable, Default, Clone)]
 176 struct Dist {
 177     sign_folder: Option<String>,
 178     gpg_password_file: Option<String>,
 179     upload_addr: Option<String>,
 180 }
 181
 182 #[derive(RustcDecodable)]
 183 enum StringOrBool {
 184     String(String),
 185     Bool(bool),
 186 }
 187
 188 impl Default for StringOrBool {
 189     fn default() -> StringOrBool {
 190         StringOrBool::Bool(false)
 191     }
 192 }
 193
 194 /// TOML representation of how the Rust build is configured.
 195 #[derive(RustcDecodable, Default)]
 196 struct Rust {
 197     optimize: Option<bool>,
 198     codegen_units: Option<u32>,
 199     debug_assertions: Option<bool>,
 200     debuginfo: Option<bool>,
 201     debuginfo_lines: Option<bool>,
 202     debuginfo_only_std: Option<bool>,
 203     debug_jemalloc: Option<bool>,
 204     use_jemalloc: Option<bool>,
 205     backtrace: Option<bool>,
 206     default_linker: Option<String>,
 207     default_ar: Option<String>,
 208     channel: Option<String>,
 209     musl_root: Option<String>,
 210     rpath: Option<bool>,
 211     optimize_tests: Option<bool>,
 212     debuginfo_tests: Option<bool>,
 213     codegen_tests: Option<bool>,
 214 }
 215
 216 /// TOML representation of how each build target is configured.
 217 #[derive(RustcDecodable, Default)]
 218 struct TomlTarget {
 219     llvm_config: Option<String>,
 220     jemalloc: Option<String>,
 221     cc: Option<String>,
 222     cxx: Option<String>,
 223     android_ndk: Option<String>,
 224     musl_root: Option<String>,
 225 }
 226
 227 impl Config {
 228     pub fn parse(build: &str, file: Option<PathBuf>) -> Config {
 229         let mut config = Config::default();
 230         config.llvm_optimize = true;
 231         config.use_jemalloc = true;
 232         config.backtrace = true;
 233         config.rust_optimize = true;
 234         config.rust_optimize_tests = true;
 235         config.submodules = true;
 236         config.docs = true;
 237         config.rust_rpath = true;
 238         config.rust_codegen_units = 1;
 239         config.build = build.to_string();
 240         config.channel = "dev".to_string();
 241         config.codegen_tests = true;
 242
 243         let toml = file.map(|file| {
 244             let mut f = t!(File::open(&file));
 245             let mut toml = String::new();
 246             t!(f.read_to_string(&mut toml));
 247             let mut p = Parser::new(&toml);
 248             let table = match p.parse() {
 249                 Some(table) => table,
 250                 None => {
 251                     println!("failed to parse TOML configuration:");
 252                     for err in p.errors.iter() {
 253                         let (loline, locol) = p.to_linecol(err.lo);
 254                         let (hiline, hicol) = p.to_linecol(err.hi);
 255                         println!("{}:{}-{}:{}: {}", loline, locol, hiline,
 256                                  hicol, err.desc);
 257                     }
 258                     process::exit(2);
 259                 }
 260             };
 261             let mut d = Decoder::new(Value::Table(table));
 262             match Decodable::decode(&mut d) {
 263                 Ok(cfg) => cfg,
 264                 Err(e) => {
 265                     println!("failed to decode TOML: {}", e);
 266                     process::exit(2);
 267                 }
 268             }
 269         }).unwrap_or_else(|| TomlConfig::default());
 270
 271         let build = toml.build.clone().unwrap_or(Build::default());
 272         set(&mut config.build, build.build.clone());
 273         config.host.push(config.build.clone());
 274         for host in build.host.iter() {
 275             if !config.host.contains(host) {
 276                 config.host.push(host.clone());
 277             }
 278         }
 279         for target in config.host.iter().chain(&build.target) {
 280             if !config.target.contains(target) {
 281                 config.target.push(target.clone());
 282             }
 283         }
 284         config.rustc = build.rustc.map(PathBuf::from);
 285         config.cargo = build.cargo.map(PathBuf::from);
 286         config.nodejs = build.nodejs.map(PathBuf::from);
 287         config.gdb = build.gdb.map(PathBuf::from);
 288         config.python = build.python.map(PathBuf::from);
 289         set(&mut config.compiler_docs, build.compiler_docs);
 290         set(&mut config.docs, build.docs);
 291         set(&mut config.submodules, build.submodules);
 292         set(&mut config.vendor, build.vendor);
 293         set(&mut config.full_bootstrap, build.full_bootstrap);
 294         set(&mut config.extended, build.extended);
 295
 296         if let Some(ref install) = toml.install {
 297             config.prefix = install.prefix.clone().map(PathBuf::from);
 298             config.mandir = install.mandir.clone().map(PathBuf::from);
 299             config.docdir = install.docdir.clone().map(PathBuf::from);
 300             config.libdir = install.libdir.clone().map(PathBuf::from);
 301         }
 302
 303         if let Some(ref llvm) = toml.llvm {
 304             match llvm.ccache {
 305                 Some(StringOrBool::String(ref s)) => {
 306                     config.ccache = Some(s.to_string())
 307                 }
 308                 Some(StringOrBool::Bool(true)) => {
 309                     config.ccache = Some("ccache".to_string());
 310                 }
 311                 Some(StringOrBool::Bool(false)) | None => {}
 312             }
 313             set(&mut config.ninja, llvm.ninja);
 314             set(&mut config.llvm_assertions, llvm.assertions);
 315             set(&mut config.llvm_optimize, llvm.optimize);
 316             set(&mut config.llvm_release_debuginfo, llvm.release_debuginfo);
 317             set(&mut config.llvm_version_check, llvm.version_check);
 318             set(&mut config.llvm_static_stdcpp, llvm.static_libstdcpp);
 319             config.llvm_targets = llvm.targets.clone();
 320         }
 321
 322         if let Some(ref rust) = toml.rust {
 323             set(&mut config.rust_debug_assertions, rust.debug_assertions);
 324             set(&mut config.rust_debuginfo, rust.debuginfo);
 325             set(&mut config.rust_debuginfo_lines, rust.debuginfo_lines);
 326             set(&mut config.rust_debuginfo_only_std, rust.debuginfo_only_std);
 327             set(&mut config.rust_optimize, rust.optimize);
 328             set(&mut config.rust_optimize_tests, rust.optimize_tests);
 329             set(&mut config.rust_debuginfo_tests, rust.debuginfo_tests);
 330             set(&mut config.codegen_tests, rust.codegen_tests);
 331             set(&mut config.rust_rpath, rust.rpath);
 332             set(&mut config.debug_jemalloc, rust.debug_jemalloc);
 333             set(&mut config.use_jemalloc, rust.use_jemalloc);
 334             set(&mut config.backtrace, rust.backtrace);
 335             set(&mut config.channel, rust.channel.clone());
 336             config.rustc_default_linker = rust.default_linker.clone();
 337             config.rustc_default_ar = rust.default_ar.clone();
 338             config.musl_root = rust.musl_root.clone().map(PathBuf::from);
 339
 340             match rust.codegen_units {
 341                 Some(0) => config.rust_codegen_units = num_cpus::get() as u32,
 342                 Some(n) => config.rust_codegen_units = n,
 343                 None => {}
 344             }
 345         }
 346
 347         if let Some(ref t) = toml.target {
 348             for (triple, cfg) in t {
 349                 let mut target = Target::default();
 350
 351                 if let Some(ref s) = cfg.llvm_config {
 352                     target.llvm_config = Some(env::current_dir().unwrap().join(s));
 353                 }
 354                 if let Some(ref s) = cfg.jemalloc {
 355                     target.jemalloc = Some(env::current_dir().unwrap().join(s));
 356                 }
 357                 if let Some(ref s) = cfg.android_ndk {
 358                     target.ndk = Some(env::current_dir().unwrap().join(s));
 359                 }
 360                 target.cxx = cfg.cxx.clone().map(PathBuf::from);
 361                 target.cc = cfg.cc.clone().map(PathBuf::from);
 362                 target.musl_root = cfg.musl_root.clone().map(PathBuf::from);
 363
 364                 config.target_config.insert(triple.clone(), target);
 365             }
 366         }
 367
 368         if let Some(ref t) = toml.dist {
 369             config.dist_sign_folder = t.sign_folder.clone().map(PathBuf::from);
 370             config.dist_gpg_password_file = t.gpg_password_file.clone().map(PathBuf::from);
 371             config.dist_upload_addr = t.upload_addr.clone();
 372         }
 373
 374         return config
 375     }
 376
 377     /// "Temporary" routine to parse `config.mk` into this configuration.
 378     ///
 379     /// While we still have `./configure` this implements the ability to decode
 380     /// that configuration into this. This isn't exactly a full-blown makefile
 381     /// parser, but hey it gets the job done!
 382     pub fn update_with_config_mk(&mut self) {
 383         let mut config = String::new();
 384         File::open("config.mk").unwrap().read_to_string(&mut config).unwrap();
 385         for line in config.lines() {
 386             let mut parts = line.splitn(2, ":=").map(|s| s.trim());
 387             let key = parts.next().unwrap();
 388             let value = match parts.next() {
 389                 Some(n) if n.starts_with('\"') => &n[1..n.len() - 1],
 390                 Some(n) => n,
 391                 None => continue
 392             };
 393
 394             macro_rules! check {
 395                 ($(($name:expr, $val:expr),)*) => {
 396                     if value == "1" {
 397                         $(
 398                             if key == concat!("CFG_ENABLE_", $name) {
 399                                 $val = true;
 400                                 continue
 401                             }
 402                             if key == concat!("CFG_DISABLE_", $name) {
 403                                 $val = false;
 404                                 continue
 405                             }
 406                         )*
 407                     }
 408                 }
 409             }
 410
 411             check! {
 412                 ("MANAGE_SUBMODULES", self.submodules),
 413                 ("COMPILER_DOCS", self.compiler_docs),
 414                 ("DOCS", self.docs),
 415                 ("LLVM_ASSERTIONS", self.llvm_assertions),
 416                 ("LLVM_RELEASE_DEBUGINFO", self.llvm_release_debuginfo),
 417                 ("OPTIMIZE_LLVM", self.llvm_optimize),
 418                 ("LLVM_VERSION_CHECK", self.llvm_version_check),
 419                 ("LLVM_STATIC_STDCPP", self.llvm_static_stdcpp),
 420                 ("LLVM_LINK_SHARED", self.llvm_link_shared),
 421                 ("OPTIMIZE", self.rust_optimize),
 422                 ("DEBUG_ASSERTIONS", self.rust_debug_assertions),
 423                 ("DEBUGINFO", self.rust_debuginfo),
 424                 ("DEBUGINFO_LINES", self.rust_debuginfo_lines),
 425                 ("DEBUGINFO_ONLY_STD", self.rust_debuginfo_only_std),
 426                 ("JEMALLOC", self.use_jemalloc),
 427                 ("DEBUG_JEMALLOC", self.debug_jemalloc),
 428                 ("RPATH", self.rust_rpath),
 429                 ("OPTIMIZE_TESTS", self.rust_optimize_tests),
 430                 ("DEBUGINFO_TESTS", self.rust_debuginfo_tests),
 431                 ("QUIET_TESTS", self.quiet_tests),
 432                 ("LOCAL_REBUILD", self.local_rebuild),
 433                 ("NINJA", self.ninja),
 434                 ("CODEGEN_TESTS", self.codegen_tests),
 435                 ("VENDOR", self.vendor),
 436                 ("FULL_BOOTSTRAP", self.full_bootstrap),
 437                 ("EXTENDED", self.extended),
 438             }
 439
 440             match key {
 441                 "CFG_BUILD" => self.build = value.to_string(),
 442                 "CFG_HOST" => {
 443                     self.host = value.split(" ").map(|s| s.to_string())
 444                                      .collect();
 445                 }
 446                 "CFG_TARGET" => {
 447                     self.target = value.split(" ").map(|s| s.to_string())
 448                                        .collect();
 449                 }
 450                 "CFG_MUSL_ROOT" if value.len() > 0 => {
 451                     self.musl_root = Some(parse_configure_path(value));
 452                 }
 453                 "CFG_MUSL_ROOT_X86_64" if value.len() > 0 => {
 454                     let target = "x86_64-unknown-linux-musl".to_string();
 455                     let target = self.target_config.entry(target)
 456                                      .or_insert(Target::default());
 457                     target.musl_root = Some(parse_configure_path(value));
 458                 }
 459                 "CFG_MUSL_ROOT_I686" if value.len() > 0 => {
 460                     let target = "i686-unknown-linux-musl".to_string();
 461                     let target = self.target_config.entry(target)
 462                                      .or_insert(Target::default());
 463                     target.musl_root = Some(parse_configure_path(value));
 464                 }
 465                 "CFG_MUSL_ROOT_ARM" if value.len() > 0 => {
 466                     let target = "arm-unknown-linux-musleabi".to_string();
 467                     let target = self.target_config.entry(target)
 468                                      .or_insert(Target::default());
 469                     target.musl_root = Some(parse_configure_path(value));
 470                 }
 471                 "CFG_MUSL_ROOT_ARMHF" if value.len() > 0 => {
 472                     let target = "arm-unknown-linux-musleabihf".to_string();
 473                     let target = self.target_config.entry(target)
 474                                      .or_insert(Target::default());
 475                     target.musl_root = Some(parse_configure_path(value));
 476                 }
 477                 "CFG_MUSL_ROOT_ARMV7" if value.len() > 0 => {
 478                     let target = "armv7-unknown-linux-musleabihf".to_string();
 479                     let target = self.target_config.entry(target)
 480                                      .or_insert(Target::default());
 481                     target.musl_root = Some(parse_configure_path(value));
 482                 }
 483                 "CFG_DEFAULT_AR" if value.len() > 0 => {
 484                     self.rustc_default_ar = Some(value.to_string());
 485                 }
 486                 "CFG_DEFAULT_LINKER" if value.len() > 0 => {
 487                     self.rustc_default_linker = Some(value.to_string());
 488                 }
 489                 "CFG_GDB" if value.len() > 0 => {
 490                     self.gdb = Some(parse_configure_path(value));
 491                 }
 492                 "CFG_RELEASE_CHANNEL" => {
 493                     self.channel = value.to_string();
 494                 }
 495                 "CFG_PREFIX" => {
 496                     self.prefix = Some(PathBuf::from(value));
 497                 }
 498                 "CFG_DOCDIR" => {
 499                     self.docdir = Some(PathBuf::from(value));
 500                 }
 501                 "CFG_LIBDIR" => {
 502                     self.libdir = Some(PathBuf::from(value));
 503                 }
 504                 "CFG_LIBDIR_RELATIVE" => {
 505                     self.libdir_relative = Some(PathBuf::from(value));
 506                 }
 507                 "CFG_MANDIR" => {
 508                     self.mandir = Some(PathBuf::from(value));
 509                 }
 510                 "CFG_LLVM_ROOT" if value.len() > 0 => {
 511                     let target = self.target_config.entry(self.build.clone())
 512                                      .or_insert(Target::default());
 513                     let root = parse_configure_path(value);
 514                     target.llvm_config = Some(push_exe_path(root, &["bin", "llvm-config"]));
 515                 }
 516                 "CFG_JEMALLOC_ROOT" if value.len() > 0 => {
 517                     let target = self.target_config.entry(self.build.clone())
 518                                      .or_insert(Target::default());
 519                     target.jemalloc = Some(parse_configure_path(value).join("libjemalloc_pic.a"));
 520                 }
 521                 "CFG_ARM_LINUX_ANDROIDEABI_NDK" if value.len() > 0 => {
 522                     let target = "arm-linux-androideabi".to_string();
 523                     let target = self.target_config.entry(target)
 524                                      .or_insert(Target::default());
 525                     target.ndk = Some(parse_configure_path(value));
 526                 }
 527                 "CFG_ARMV7_LINUX_ANDROIDEABI_NDK" if value.len() > 0 => {
 528                     let target = "armv7-linux-androideabi".to_string();
 529                     let target = self.target_config.entry(target)
 530                                      .or_insert(Target::default());
 531                     target.ndk = Some(parse_configure_path(value));
 532                 }
 533                 "CFG_I686_LINUX_ANDROID_NDK" if value.len() > 0 => {
 534                     let target = "i686-linux-android".to_string();
 535                     let target = self.target_config.entry(target)
 536                                      .or_insert(Target::default());
 537                     target.ndk = Some(parse_configure_path(value));
 538                 }
 539                 "CFG_AARCH64_LINUX_ANDROID_NDK" if value.len() > 0 => {
 540                     let target = "aarch64-linux-android".to_string();
 541                     let target = self.target_config.entry(target)
 542                                      .or_insert(Target::default());
 543                     target.ndk = Some(parse_configure_path(value));
 544                 }
 545                 "CFG_LOCAL_RUST_ROOT" if value.len() > 0 => {
 546                     let path = parse_configure_path(value);
 547                     self.rustc = Some(push_exe_path(path.clone(), &["bin", "rustc"]));
 548                     self.cargo = Some(push_exe_path(path, &["bin", "cargo"]));
 549                 }
 550                 "CFG_PYTHON" if value.len() > 0 => {
 551                     let path = parse_configure_path(value);
 552                     self.python = Some(path);
 553                 }
 554                 "CFG_ENABLE_CCACHE" if value == "1" => {
 555                     self.ccache = Some("ccache".to_string());
 556                 }
 557                 "CFG_ENABLE_SCCACHE" if value == "1" => {
 558                     self.ccache = Some("sccache".to_string());
 559                 }
 560                 "CFG_CONFIGURE_ARGS" if value.len() > 0 => {
 561                     self.configure_args = value.split_whitespace()
 562                                                .map(|s| s.to_string())
 563                                                .collect();
 564                 }
 565                 _ => {}
 566             }
 567         }
 568     }
 569
 570     pub fn verbose(&self) -> bool {
 571         self.verbose > 0
 572     }
 573
 574     pub fn very_verbose(&self) -> bool {
 575         self.verbose > 1
 576     }
 577 }
 578
 579 #[cfg(not(windows))]
 580 fn parse_configure_path(path: &str) -> PathBuf {
 581     path.into()
 582 }
 583
 584 #[cfg(windows)]
 585 fn parse_configure_path(path: &str) -> PathBuf {
 586     // on windows, configure produces unix style paths e.g. /c/some/path but we
 587     // only want real windows paths
 588
 589     use std::process::Command;
 590     use build_helper;
 591
 592     // '/' is invalid in windows paths, so we can detect unix paths by the presence of it
 593     if !path.contains('/') {
 594         return path.into();
 595     }
 596
 597     let win_path = build_helper::output(Command::new("cygpath").arg("-w").arg(path));
 598     let win_path = win_path.trim();
 599
 600     win_path.into()
 601 }
 602
 603 fn set<T>(field: &mut T, val: Option<T>) {
 604     if let Some(v) = val {
 605         *field = v;
 606     }
 607 }