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     pub sanitizers: bool,
  52
  53     // llvm codegen options
  54     pub llvm_assertions: bool,
  55     pub llvm_optimize: bool,
  56     pub llvm_release_debuginfo: bool,
  57     pub llvm_version_check: bool,
  58     pub llvm_static_stdcpp: bool,
  59     pub llvm_link_shared: bool,
  60     pub llvm_targets: Option<String>,
  61
  62     // rust codegen options
  63     pub rust_optimize: bool,
  64     pub rust_codegen_units: u32,
  65     pub rust_debug_assertions: bool,
  66     pub rust_debuginfo: bool,
  67     pub rust_debuginfo_lines: bool,
  68     pub rust_debuginfo_only_std: bool,
  69     pub rust_rpath: bool,
  70     pub rustc_default_linker: Option<String>,
  71     pub rustc_default_ar: Option<String>,
  72     pub rust_optimize_tests: bool,
  73     pub rust_debuginfo_tests: bool,
  74
  75     pub build: String,
  76     pub host: Vec<String>,
  77     pub target: Vec<String>,
  78     pub rustc: Option<PathBuf>,
  79     pub cargo: Option<PathBuf>,
  80     pub local_rebuild: bool,
  81
  82     // dist misc
  83     pub dist_sign_folder: Option<PathBuf>,
  84     pub dist_upload_addr: Option<String>,
  85     pub dist_gpg_password_file: Option<PathBuf>,
  86
  87     // libstd features
  88     pub debug_jemalloc: bool,
  89     pub use_jemalloc: bool,
  90     pub backtrace: bool, // support for RUST_BACKTRACE
  91
  92     // misc
  93     pub channel: String,
  94     pub quiet_tests: bool,
  95     // Fallback musl-root for all targets
  96     pub musl_root: Option<PathBuf>,
  97     pub prefix: Option<PathBuf>,
  98     pub docdir: Option<PathBuf>,
  99     pub libdir: Option<PathBuf>,
 100     pub libdir_relative: Option<PathBuf>,
 101     pub mandir: Option<PathBuf>,
 102     pub codegen_tests: bool,
 103     pub nodejs: Option<PathBuf>,
 104     pub gdb: Option<PathBuf>,
 105     pub python: Option<PathBuf>,
 106     pub configure_args: Vec<String>,
 107 }
 108
 109 /// Per-target configuration stored in the global configuration structure.
 110 #[derive(Default)]
 111 pub struct Target {
 112     pub llvm_config: Option<PathBuf>,
 113     pub jemalloc: Option<PathBuf>,
 114     pub cc: Option<PathBuf>,
 115     pub cxx: Option<PathBuf>,
 116     pub ndk: Option<PathBuf>,
 117     pub musl_root: Option<PathBuf>,
 118     pub qemu_rootfs: Option<PathBuf>,
 119 }
 120
 121 /// Structure of the `config.toml` file that configuration is read from.
 122 ///
 123 /// This structure uses `Decodable` to automatically decode a TOML configuration
 124 /// file into this format, and then this is traversed and written into the above
 125 /// `Config` structure.
 126 #[derive(RustcDecodable, Default)]
 127 struct TomlConfig {
 128     build: Option<Build>,
 129     install: Option<Install>,
 130     llvm: Option<Llvm>,
 131     rust: Option<Rust>,
 132     target: Option<HashMap<String, TomlTarget>>,
 133     dist: Option<Dist>,
 134 }
 135
 136 /// TOML representation of various global build decisions.
 137 #[derive(RustcDecodable, Default, Clone)]
 138 struct Build {
 139     build: Option<String>,
 140     host: Vec<String>,
 141     target: Vec<String>,
 142     cargo: Option<String>,
 143     rustc: Option<String>,
 144     compiler_docs: Option<bool>,
 145     docs: Option<bool>,
 146     submodules: Option<bool>,
 147     gdb: Option<String>,
 148     vendor: Option<bool>,
 149     nodejs: Option<String>,
 150     python: Option<String>,
 151     full_bootstrap: Option<bool>,
 152     extended: Option<bool>,
 153     sanitizers: Option<bool>,
 154 }
 155
 156 /// TOML representation of various global install decisions.
 157 #[derive(RustcDecodable, Default, Clone)]
 158 struct Install {
 159     prefix: Option<String>,
 160     mandir: Option<String>,
 161     docdir: Option<String>,
 162     libdir: Option<String>,
 163 }
 164
 165 /// TOML representation of how the LLVM build is configured.
 166 #[derive(RustcDecodable, Default)]
 167 struct Llvm {
 168     ccache: Option<StringOrBool>,
 169     ninja: Option<bool>,
 170     assertions: Option<bool>,
 171     optimize: Option<bool>,
 172     release_debuginfo: Option<bool>,
 173     version_check: Option<bool>,
 174     static_libstdcpp: Option<bool>,
 175     targets: Option<String>,
 176 }
 177
 178 #[derive(RustcDecodable, Default, Clone)]
 179 struct Dist {
 180     sign_folder: Option<String>,
 181     gpg_password_file: Option<String>,
 182     upload_addr: Option<String>,
 183 }
 184
 185 #[derive(RustcDecodable)]
 186 enum StringOrBool {
 187     String(String),
 188     Bool(bool),
 189 }
 190
 191 impl Default for StringOrBool {
 192     fn default() -> StringOrBool {
 193         StringOrBool::Bool(false)
 194     }
 195 }
 196
 197 /// TOML representation of how the Rust build is configured.
 198 #[derive(RustcDecodable, Default)]
 199 struct Rust {
 200     optimize: Option<bool>,
 201     codegen_units: Option<u32>,
 202     debug_assertions: Option<bool>,
 203     debuginfo: Option<bool>,
 204     debuginfo_lines: Option<bool>,
 205     debuginfo_only_std: Option<bool>,
 206     debug_jemalloc: Option<bool>,
 207     use_jemalloc: Option<bool>,
 208     backtrace: Option<bool>,
 209     default_linker: Option<String>,
 210     default_ar: Option<String>,
 211     channel: Option<String>,
 212     musl_root: Option<String>,
 213     rpath: Option<bool>,
 214     optimize_tests: Option<bool>,
 215     debuginfo_tests: Option<bool>,
 216     codegen_tests: Option<bool>,
 217 }
 218
 219 /// TOML representation of how each build target is configured.
 220 #[derive(RustcDecodable, Default)]
 221 struct TomlTarget {
 222     llvm_config: Option<String>,
 223     jemalloc: Option<String>,
 224     cc: Option<String>,
 225     cxx: Option<String>,
 226     android_ndk: Option<String>,
 227     musl_root: Option<String>,
 228     qemu_rootfs: Option<String>,
 229 }
 230
 231 impl Config {
 232     pub fn parse(build: &str, file: Option<PathBuf>) -> Config {
 233         let mut config = Config::default();
 234         config.llvm_optimize = true;
 235         config.use_jemalloc = true;
 236         config.backtrace = true;
 237         config.rust_optimize = true;
 238         config.rust_optimize_tests = true;
 239         config.submodules = true;
 240         config.docs = true;
 241         config.rust_rpath = true;
 242         config.rust_codegen_units = 1;
 243         config.build = build.to_string();
 244         config.channel = "dev".to_string();
 245         config.codegen_tests = true;
 246
 247         let toml = file.map(|file| {
 248             let mut f = t!(File::open(&file));
 249             let mut toml = String::new();
 250             t!(f.read_to_string(&mut toml));
 251             let mut p = Parser::new(&toml);
 252             let table = match p.parse() {
 253                 Some(table) => table,
 254                 None => {
 255                     println!("failed to parse TOML configuration:");
 256                     for err in p.errors.iter() {
 257                         let (loline, locol) = p.to_linecol(err.lo);
 258                         let (hiline, hicol) = p.to_linecol(err.hi);
 259                         println!("{}:{}-{}:{}: {}", loline, locol, hiline,
 260                                  hicol, err.desc);
 261                     }
 262                     process::exit(2);
 263                 }
 264             };
 265             let mut d = Decoder::new(Value::Table(table));
 266             match Decodable::decode(&mut d) {
 267                 Ok(cfg) => cfg,
 268                 Err(e) => {
 269                     println!("failed to decode TOML: {}", e);
 270                     process::exit(2);
 271                 }
 272             }
 273         }).unwrap_or_else(|| TomlConfig::default());
 274
 275         let build = toml.build.clone().unwrap_or(Build::default());
 276         set(&mut config.build, build.build.clone());
 277         config.host.push(config.build.clone());
 278         for host in build.host.iter() {
 279             if !config.host.contains(host) {
 280                 config.host.push(host.clone());
 281             }
 282         }
 283         for target in config.host.iter().chain(&build.target) {
 284             if !config.target.contains(target) {
 285                 config.target.push(target.clone());
 286             }
 287         }
 288         config.rustc = build.rustc.map(PathBuf::from);
 289         config.cargo = build.cargo.map(PathBuf::from);
 290         config.nodejs = build.nodejs.map(PathBuf::from);
 291         config.gdb = build.gdb.map(PathBuf::from);
 292         config.python = build.python.map(PathBuf::from);
 293         set(&mut config.compiler_docs, build.compiler_docs);
 294         set(&mut config.docs, build.docs);
 295         set(&mut config.submodules, build.submodules);
 296         set(&mut config.vendor, build.vendor);
 297         set(&mut config.full_bootstrap, build.full_bootstrap);
 298         set(&mut config.extended, build.extended);
 299         set(&mut config.sanitizers, build.sanitizers);
 300
 301         if let Some(ref install) = toml.install {
 302             config.prefix = install.prefix.clone().map(PathBuf::from);
 303             config.mandir = install.mandir.clone().map(PathBuf::from);
 304             config.docdir = install.docdir.clone().map(PathBuf::from);
 305             config.libdir = install.libdir.clone().map(PathBuf::from);
 306         }
 307
 308         if let Some(ref llvm) = toml.llvm {
 309             match llvm.ccache {
 310                 Some(StringOrBool::String(ref s)) => {
 311                     config.ccache = Some(s.to_string())
 312                 }
 313                 Some(StringOrBool::Bool(true)) => {
 314                     config.ccache = Some("ccache".to_string());
 315                 }
 316                 Some(StringOrBool::Bool(false)) | None => {}
 317             }
 318             set(&mut config.ninja, llvm.ninja);
 319             set(&mut config.llvm_assertions, llvm.assertions);
 320             set(&mut config.llvm_optimize, llvm.optimize);
 321             set(&mut config.llvm_release_debuginfo, llvm.release_debuginfo);
 322             set(&mut config.llvm_version_check, llvm.version_check);
 323             set(&mut config.llvm_static_stdcpp, llvm.static_libstdcpp);
 324             config.llvm_targets = llvm.targets.clone();
 325         }
 326
 327         if let Some(ref rust) = toml.rust {
 328             set(&mut config.rust_debug_assertions, rust.debug_assertions);
 329             set(&mut config.rust_debuginfo, rust.debuginfo);
 330             set(&mut config.rust_debuginfo_lines, rust.debuginfo_lines);
 331             set(&mut config.rust_debuginfo_only_std, rust.debuginfo_only_std);
 332             set(&mut config.rust_optimize, rust.optimize);
 333             set(&mut config.rust_optimize_tests, rust.optimize_tests);
 334             set(&mut config.rust_debuginfo_tests, rust.debuginfo_tests);
 335             set(&mut config.codegen_tests, rust.codegen_tests);
 336             set(&mut config.rust_rpath, rust.rpath);
 337             set(&mut config.debug_jemalloc, rust.debug_jemalloc);
 338             set(&mut config.use_jemalloc, rust.use_jemalloc);
 339             set(&mut config.backtrace, rust.backtrace);
 340             set(&mut config.channel, rust.channel.clone());
 341             config.rustc_default_linker = rust.default_linker.clone();
 342             config.rustc_default_ar = rust.default_ar.clone();
 343             config.musl_root = rust.musl_root.clone().map(PathBuf::from);
 344
 345             match rust.codegen_units {
 346                 Some(0) => config.rust_codegen_units = num_cpus::get() as u32,
 347                 Some(n) => config.rust_codegen_units = n,
 348                 None => {}
 349             }
 350         }
 351
 352         if let Some(ref t) = toml.target {
 353             for (triple, cfg) in t {
 354                 let mut target = Target::default();
 355
 356                 if let Some(ref s) = cfg.llvm_config {
 357                     target.llvm_config = Some(env::current_dir().unwrap().join(s));
 358                 }
 359                 if let Some(ref s) = cfg.jemalloc {
 360                     target.jemalloc = Some(env::current_dir().unwrap().join(s));
 361                 }
 362                 if let Some(ref s) = cfg.android_ndk {
 363                     target.ndk = Some(env::current_dir().unwrap().join(s));
 364                 }
 365                 target.cxx = cfg.cxx.clone().map(PathBuf::from);
 366                 target.cc = cfg.cc.clone().map(PathBuf::from);
 367                 target.musl_root = cfg.musl_root.clone().map(PathBuf::from);
 368                 target.qemu_rootfs = cfg.qemu_rootfs.clone().map(PathBuf::from);
 369
 370                 config.target_config.insert(triple.clone(), target);
 371             }
 372         }
 373
 374         if let Some(ref t) = toml.dist {
 375             config.dist_sign_folder = t.sign_folder.clone().map(PathBuf::from);
 376             config.dist_gpg_password_file = t.gpg_password_file.clone().map(PathBuf::from);
 377             config.dist_upload_addr = t.upload_addr.clone();
 378         }
 379
 380         return config
 381     }
 382
 383     /// "Temporary" routine to parse `config.mk` into this configuration.
 384     ///
 385     /// While we still have `./configure` this implements the ability to decode
 386     /// that configuration into this. This isn't exactly a full-blown makefile
 387     /// parser, but hey it gets the job done!
 388     pub fn update_with_config_mk(&mut self) {
 389         let mut config = String::new();
 390         File::open("config.mk").unwrap().read_to_string(&mut config).unwrap();
 391         for line in config.lines() {
 392             let mut parts = line.splitn(2, ":=").map(|s| s.trim());
 393             let key = parts.next().unwrap();
 394             let value = match parts.next() {
 395                 Some(n) if n.starts_with('\"') => &n[1..n.len() - 1],
 396                 Some(n) => n,
 397                 None => continue
 398             };
 399
 400             macro_rules! check {
 401                 ($(($name:expr, $val:expr),)*) => {
 402                     if value == "1" {
 403                         $(
 404                             if key == concat!("CFG_ENABLE_", $name) {
 405                                 $val = true;
 406                                 continue
 407                             }
 408                             if key == concat!("CFG_DISABLE_", $name) {
 409                                 $val = false;
 410                                 continue
 411                             }
 412                         )*
 413                     }
 414                 }
 415             }
 416
 417             check! {
 418                 ("MANAGE_SUBMODULES", self.submodules),
 419                 ("COMPILER_DOCS", self.compiler_docs),
 420                 ("DOCS", self.docs),
 421                 ("LLVM_ASSERTIONS", self.llvm_assertions),
 422                 ("LLVM_RELEASE_DEBUGINFO", self.llvm_release_debuginfo),
 423                 ("OPTIMIZE_LLVM", self.llvm_optimize),
 424                 ("LLVM_VERSION_CHECK", self.llvm_version_check),
 425                 ("LLVM_STATIC_STDCPP", self.llvm_static_stdcpp),
 426                 ("LLVM_LINK_SHARED", self.llvm_link_shared),
 427                 ("OPTIMIZE", self.rust_optimize),
 428                 ("DEBUG_ASSERTIONS", self.rust_debug_assertions),
 429                 ("DEBUGINFO", self.rust_debuginfo),
 430                 ("DEBUGINFO_LINES", self.rust_debuginfo_lines),
 431                 ("DEBUGINFO_ONLY_STD", self.rust_debuginfo_only_std),
 432                 ("JEMALLOC", self.use_jemalloc),
 433                 ("DEBUG_JEMALLOC", self.debug_jemalloc),
 434                 ("RPATH", self.rust_rpath),
 435                 ("OPTIMIZE_TESTS", self.rust_optimize_tests),
 436                 ("DEBUGINFO_TESTS", self.rust_debuginfo_tests),
 437                 ("QUIET_TESTS", self.quiet_tests),
 438                 ("LOCAL_REBUILD", self.local_rebuild),
 439                 ("NINJA", self.ninja),
 440                 ("CODEGEN_TESTS", self.codegen_tests),
 441                 ("VENDOR", self.vendor),
 442                 ("FULL_BOOTSTRAP", self.full_bootstrap),
 443                 ("EXTENDED", self.extended),
 444                 ("SANITIZERS", self.sanitizers),
 445             }
 446
 447             match key {
 448                 "CFG_BUILD" => self.build = value.to_string(),
 449                 "CFG_HOST" => {
 450                     self.host = value.split(" ").map(|s| s.to_string())
 451                                      .collect();
 452                 }
 453                 "CFG_TARGET" => {
 454                     self.target = value.split(" ").map(|s| s.to_string())
 455                                        .collect();
 456                 }
 457                 "CFG_MUSL_ROOT" if value.len() > 0 => {
 458                     self.musl_root = Some(parse_configure_path(value));
 459                 }
 460                 "CFG_MUSL_ROOT_X86_64" if value.len() > 0 => {
 461                     let target = "x86_64-unknown-linux-musl".to_string();
 462                     let target = self.target_config.entry(target)
 463                                      .or_insert(Target::default());
 464                     target.musl_root = Some(parse_configure_path(value));
 465                 }
 466                 "CFG_MUSL_ROOT_I686" if value.len() > 0 => {
 467                     let target = "i686-unknown-linux-musl".to_string();
 468                     let target = self.target_config.entry(target)
 469                                      .or_insert(Target::default());
 470                     target.musl_root = Some(parse_configure_path(value));
 471                 }
 472                 "CFG_MUSL_ROOT_ARM" if value.len() > 0 => {
 473                     let target = "arm-unknown-linux-musleabi".to_string();
 474                     let target = self.target_config.entry(target)
 475                                      .or_insert(Target::default());
 476                     target.musl_root = Some(parse_configure_path(value));
 477                 }
 478                 "CFG_MUSL_ROOT_ARMHF" if value.len() > 0 => {
 479                     let target = "arm-unknown-linux-musleabihf".to_string();
 480                     let target = self.target_config.entry(target)
 481                                      .or_insert(Target::default());
 482                     target.musl_root = Some(parse_configure_path(value));
 483                 }
 484                 "CFG_MUSL_ROOT_ARMV7" if value.len() > 0 => {
 485                     let target = "armv7-unknown-linux-musleabihf".to_string();
 486                     let target = self.target_config.entry(target)
 487                                      .or_insert(Target::default());
 488                     target.musl_root = Some(parse_configure_path(value));
 489                 }
 490                 "CFG_DEFAULT_AR" if value.len() > 0 => {
 491                     self.rustc_default_ar = Some(value.to_string());
 492                 }
 493                 "CFG_DEFAULT_LINKER" if value.len() > 0 => {
 494                     self.rustc_default_linker = Some(value.to_string());
 495                 }
 496                 "CFG_GDB" if value.len() > 0 => {
 497                     self.gdb = Some(parse_configure_path(value));
 498                 }
 499                 "CFG_RELEASE_CHANNEL" => {
 500                     self.channel = value.to_string();
 501                 }
 502                 "CFG_PREFIX" => {
 503                     self.prefix = Some(PathBuf::from(value));
 504                 }
 505                 "CFG_DOCDIR" => {
 506                     self.docdir = Some(PathBuf::from(value));
 507                 }
 508                 "CFG_LIBDIR" => {
 509                     self.libdir = Some(PathBuf::from(value));
 510                 }
 511                 "CFG_LIBDIR_RELATIVE" => {
 512                     self.libdir_relative = Some(PathBuf::from(value));
 513                 }
 514                 "CFG_MANDIR" => {
 515                     self.mandir = Some(PathBuf::from(value));
 516                 }
 517                 "CFG_LLVM_ROOT" if value.len() > 0 => {
 518                     let target = self.target_config.entry(self.build.clone())
 519                                      .or_insert(Target::default());
 520                     let root = parse_configure_path(value);
 521                     target.llvm_config = Some(push_exe_path(root, &["bin", "llvm-config"]));
 522                 }
 523                 "CFG_JEMALLOC_ROOT" if value.len() > 0 => {
 524                     let target = self.target_config.entry(self.build.clone())
 525                                      .or_insert(Target::default());
 526                     target.jemalloc = Some(parse_configure_path(value).join("libjemalloc_pic.a"));
 527                 }
 528                 "CFG_ARM_LINUX_ANDROIDEABI_NDK" if value.len() > 0 => {
 529                     let target = "arm-linux-androideabi".to_string();
 530                     let target = self.target_config.entry(target)
 531                                      .or_insert(Target::default());
 532                     target.ndk = Some(parse_configure_path(value));
 533                 }
 534                 "CFG_ARMV7_LINUX_ANDROIDEABI_NDK" if value.len() > 0 => {
 535                     let target = "armv7-linux-androideabi".to_string();
 536                     let target = self.target_config.entry(target)
 537                                      .or_insert(Target::default());
 538                     target.ndk = Some(parse_configure_path(value));
 539                 }
 540                 "CFG_I686_LINUX_ANDROID_NDK" if value.len() > 0 => {
 541                     let target = "i686-linux-android".to_string();
 542                     let target = self.target_config.entry(target)
 543                                      .or_insert(Target::default());
 544                     target.ndk = Some(parse_configure_path(value));
 545                 }
 546                 "CFG_AARCH64_LINUX_ANDROID_NDK" if value.len() > 0 => {
 547                     let target = "aarch64-linux-android".to_string();
 548                     let target = self.target_config.entry(target)
 549                                      .or_insert(Target::default());
 550                     target.ndk = Some(parse_configure_path(value));
 551                 }
 552                 "CFG_LOCAL_RUST_ROOT" if value.len() > 0 => {
 553                     let path = parse_configure_path(value);
 554                     self.rustc = Some(push_exe_path(path.clone(), &["bin", "rustc"]));
 555                     self.cargo = Some(push_exe_path(path, &["bin", "cargo"]));
 556                 }
 557                 "CFG_PYTHON" if value.len() > 0 => {
 558                     let path = parse_configure_path(value);
 559                     self.python = Some(path);
 560                 }
 561                 "CFG_ENABLE_CCACHE" if value == "1" => {
 562                     self.ccache = Some("ccache".to_string());
 563                 }
 564                 "CFG_ENABLE_SCCACHE" if value == "1" => {
 565                     self.ccache = Some("sccache".to_string());
 566                 }
 567                 "CFG_CONFIGURE_ARGS" if value.len() > 0 => {
 568                     self.configure_args = value.split_whitespace()
 569                                                .map(|s| s.to_string())
 570                                                .collect();
 571                 }
 572                 "CFG_QEMU_ARMHF_ROOTFS" if value.len() > 0 => {
 573                     let target = "arm-unknown-linux-gnueabihf".to_string();
 574                     let target = self.target_config.entry(target)
 575                                      .or_insert(Target::default());
 576                     target.qemu_rootfs = Some(parse_configure_path(value));
 577                 }
 578                 _ => {}
 579             }
 580         }
 581     }
 582
 583     pub fn verbose(&self) -> bool {
 584         self.verbose > 0
 585     }
 586
 587     pub fn very_verbose(&self) -> bool {
 588         self.verbose > 1
 589     }
 590 }
 591
 592 #[cfg(not(windows))]
 593 fn parse_configure_path(path: &str) -> PathBuf {
 594     path.into()
 595 }
 596
 597 #[cfg(windows)]
 598 fn parse_configure_path(path: &str) -> PathBuf {
 599     // on windows, configure produces unix style paths e.g. /c/some/path but we
 600     // only want real windows paths
 601
 602     use std::process::Command;
 603     use build_helper;
 604
 605     // '/' is invalid in windows paths, so we can detect unix paths by the presence of it
 606     if !path.contains('/') {
 607         return path.into();
 608     }
 609
 610     let win_path = build_helper::output(Command::new("cygpath").arg("-w").arg(path));
 611     let win_path = win_path.trim();
 612
 613     win_path.into()
 614 }
 615
 616 fn set<T>(field: &mut T, val: Option<T>) {
 617     if let Some(v) = val {
 618         *field = v;
 619     }
 620 }