src/bootstrap/util.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 //! Various utility functions used throughout rustbuild.
  12 //!
  13 //! Simple things like testing the various filesystem operations here and there,
  14 //! not a lot of interesting happenings here unfortunately.
  15
  16 use std::env;
  17 use std::ffi::OsString;
  18 use std::fs;
  19 use std::path::{Path, PathBuf};
  20 use std::process::Command;
  21
  22 use filetime::FileTime;
  23
  24 /// Returns the `name` as the filename of a static library for `target`.
  25 pub fn staticlib(name: &str, target: &str) -> String {
  26     if target.contains("windows-msvc") {
  27         format!("{}.lib", name)
  28     } else {
  29         format!("lib{}.a", name)
  30     }
  31 }
  32
  33 /// Returns the last-modified time for `path`, or zero if it doesn't exist.
  34 pub fn mtime(path: &Path) -> FileTime {
  35     fs::metadata(path).map(|f| {
  36         FileTime::from_last_modification_time(&f)
  37     }).unwrap_or(FileTime::zero())
  38 }
  39
  40 /// Copies a file from `src` to `dst`, attempting to use hard links and then
  41 /// falling back to an actually filesystem copy if necessary.
  42 pub fn copy(src: &Path, dst: &Path) {
  43     let res = fs::hard_link(src, dst);
  44     let res = res.or_else(|_| fs::copy(src, dst).map(|_| ()));
  45     if let Err(e) = res {
  46         panic!("failed to copy `{}` to `{}`: {}", src.display(),
  47                dst.display(), e)
  48     }
  49 }
  50
  51 /// Copies the `src` directory recursively to `dst`. Both are assumed to exist
  52 /// when this function is called.
  53 pub fn cp_r(src: &Path, dst: &Path) {
  54     for f in t!(fs::read_dir(src)) {
  55         let f = t!(f);
  56         let path = f.path();
  57         let name = path.file_name().unwrap();
  58         let dst = dst.join(name);
  59         if t!(f.file_type()).is_dir() {
  60             let _ = fs::remove_dir_all(&dst);
  61             t!(fs::create_dir(&dst));
  62             cp_r(&path, &dst);
  63         } else {
  64             let _ = fs::remove_file(&dst);
  65             copy(&path, &dst);
  66         }
  67     }
  68 }
  69
  70 /// Copies the `src` directory recursively to `dst`. Both are assumed to exist
  71 /// when this function is called. Unwanted files or directories can be skipped
  72 /// by returning `false` from the filter function.
  73 pub fn cp_filtered<F: Fn(&Path) -> bool>(src: &Path, dst: &Path, filter: &F) {
  74     // Inner function does the actual work
  75     fn recurse<F: Fn(&Path) -> bool>(src: &Path, dst: &Path, relative: &Path, filter: &F) {
  76         for f in t!(fs::read_dir(src)) {
  77             let f = t!(f);
  78             let path = f.path();
  79             let name = path.file_name().unwrap();
  80             let dst = dst.join(name);
  81             let relative = relative.join(name);
  82             // Only copy file or directory if the filter function returns true
  83             if filter(&relative) {
  84                 if t!(f.file_type()).is_dir() {
  85                     let _ = fs::remove_dir_all(&dst);
  86                     t!(fs::create_dir(&dst));
  87                     recurse(&path, &dst, &relative, filter);
  88                 } else {
  89                     let _ = fs::remove_file(&dst);
  90                     copy(&path, &dst);
  91                 }
  92             }
  93         }
  94     }
  95     // Immediately recurse with an empty relative path
  96     recurse(src, dst, Path::new(""), filter)
  97 }
  98
  99 /// Given an executable called `name`, return the filename for the
 100 /// executable for a particular target.
 101 pub fn exe(name: &str, target: &str) -> String {
 102     if target.contains("windows") {
 103         format!("{}.exe", name)
 104     } else {
 105         name.to_string()
 106     }
 107 }
 108
 109 /// Returns whether the file name given looks like a dynamic library.
 110 pub fn is_dylib(name: &str) -> bool {
 111     name.ends_with(".dylib") || name.ends_with(".so") || name.ends_with(".dll")
 112 }
 113
 114 /// Returns the corresponding relative library directory that the compiler's
 115 /// dylibs will be found in.
 116 pub fn libdir(target: &str) -> &'static str {
 117     if target.contains("windows") {"bin"} else {"lib"}
 118 }
 119
 120 /// Adds a list of lookup paths to `cmd`'s dynamic library lookup path.
 121 pub fn add_lib_path(path: Vec<PathBuf>, cmd: &mut Command) {
 122     let mut list = dylib_path();
 123     for path in path {
 124         list.insert(0, path);
 125     }
 126     cmd.env(dylib_path_var(), t!(env::join_paths(list)));
 127 }
 128
 129 /// Returns whether `dst` is up to date given that the file or files in `src`
 130 /// are used to generate it.
 131 ///
 132 /// Uses last-modified time checks to verify this.
 133 pub fn up_to_date(src: &Path, dst: &Path) -> bool {
 134     let threshold = mtime(dst);
 135     let meta = match fs::metadata(src) {
 136         Ok(meta) => meta,
 137         Err(e) => panic!("source {:?} failed to get metadata: {}", src, e),
 138     };
 139     if meta.is_dir() {
 140         dir_up_to_date(src, &threshold)
 141     } else {
 142         FileTime::from_last_modification_time(&meta) <= threshold
 143     }
 144 }
 145
 146 fn dir_up_to_date(src: &Path, threshold: &FileTime) -> bool {
 147     t!(fs::read_dir(src)).map(|e| t!(e)).all(|e| {
 148         let meta = t!(e.metadata());
 149         if meta.is_dir() {
 150             dir_up_to_date(&e.path(), threshold)
 151         } else {
 152             FileTime::from_last_modification_time(&meta) < *threshold
 153         }
 154     })
 155 }
 156
 157 /// Returns the environment variable which the dynamic library lookup path
 158 /// resides in for this platform.
 159 pub fn dylib_path_var() -> &'static str {
 160     if cfg!(target_os = "windows") {
 161         "PATH"
 162     } else if cfg!(target_os = "macos") {
 163         "DYLD_LIBRARY_PATH"
 164     } else {
 165         "LD_LIBRARY_PATH"
 166     }
 167 }
 168
 169 /// Parses the `dylib_path_var()` environment variable, returning a list of
 170 /// paths that are members of this lookup path.
 171 pub fn dylib_path() -> Vec<PathBuf> {
 172     env::split_paths(&env::var_os(dylib_path_var()).unwrap_or(OsString::new()))
 173         .collect()
 174 }