rustbuild: Remove the `build` directory

The organization in rustbuild was a little odd at the moment where the `lib.rs`
was quite small but the binary `main.rs` was much larger. Unfortunately as well
there was a `build/` directory with the implementation of the build system, but
this directory was ignored by GitHub on the file-search prompt which was a
little annoying.

This commit reorganizes rustbuild slightly where all the library files (the
build system) is located directly inside of `src/bootstrap` and all the binaries
now live in `src/bootstrap/bin` (they're small). Hopefully this should allow
GitHub to index and allow navigating all the files while maintaining a
relatively similar layout to the other libraries in `src/`.

1 files changed, 142 insertions, 0 deletions

diff --git a/src/bootstrap/util.rs b/src/bootstrap/util.rs
new file mode 100644
index 00000000000..3ef7f8cab2d
--- /dev/null
+++ b/src/bootstrap/util.rs
@@ -0,0 +1,142 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Various utility functions used throughout rustbuild.
+//!
+//! Simple things like testing the various filesystem operations here and there,
+//! not a lot of interesting happenings here unfortunately.
+
+use std::env;
+use std::ffi::OsString;
+use std::fs;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+use filetime::FileTime;
+
+/// Returns the `name` as the filename of a static library for `target`.
+pub fn staticlib(name: &str, target: &str) -> String {
+    if target.contains("windows-msvc") {
+        format!("{}.lib", name)
+    } else {
+        format!("lib{}.a", name)
+    }
+}
+
+/// Returns the last-modified time for `path`, or zero if it doesn't exist.
+pub fn mtime(path: &Path) -> FileTime {
+    fs::metadata(path).map(|f| {
+        FileTime::from_last_modification_time(&f)
+    }).unwrap_or(FileTime::zero())
+}
+
+/// Copies a file from `src` to `dst`, attempting to use hard links and then
+/// falling back to an actually filesystem copy if necessary.
+pub fn copy(src: &Path, dst: &Path) {
+    let res = fs::hard_link(src, dst);
+    let res = res.or_else(|_| fs::copy(src, dst).map(|_| ()));
+    if let Err(e) = res {
+        panic!("failed to copy `{}` to `{}`: {}", src.display(),
+               dst.display(), e)
+    }
+}
+
+/// Copies the `src` directory recursively to `dst`. Both are assumed to exist
+/// when this function is called.
+pub fn cp_r(src: &Path, dst: &Path) {
+    for f in t!(fs::read_dir(src)) {
+        let f = t!(f);
+        let path = f.path();
+        let name = path.file_name().unwrap();
+        let dst = dst.join(name);
+        if t!(f.file_type()).is_dir() {
+            let _ = fs::remove_dir_all(&dst);
+            t!(fs::create_dir(&dst));
+            cp_r(&path, &dst);
+        } else {
+            let _ = fs::remove_file(&dst);
+            copy(&path, &dst);
+        }
+    }
+}
+
+/// Given an executable called `name`, return the filename for the
+/// executable for a particular target.
+pub fn exe(name: &str, target: &str) -> String {
+    if target.contains("windows") {
+        format!("{}.exe", name)
+    } else {
+        name.to_string()
+    }
+}
+
+/// Returns whether the file name given looks like a dynamic library.
+pub fn is_dylib(name: &str) -> bool {
+    name.ends_with(".dylib") || name.ends_with(".so") || name.ends_with(".dll")
+}
+
+/// Returns the corresponding relative library directory that the compiler's
+/// dylibs will be found in.
+pub fn libdir(target: &str) -> &'static str {
+    if target.contains("windows") {"bin"} else {"lib"}
+}
+
+/// Adds a list of lookup paths to `cmd`'s dynamic library lookup path.
+pub fn add_lib_path(path: Vec<PathBuf>, cmd: &mut Command) {
+    let mut list = dylib_path();
+    for path in path {
+        list.insert(0, path);
+    }
+    cmd.env(dylib_path_var(), t!(env::join_paths(list)));
+}
+
+/// Returns whether `dst` is up to date given that the file or files in `src`
+/// are used to generate it.
+///
+/// Uses last-modified time checks to verify this.
+pub fn up_to_date(src: &Path, dst: &Path) -> bool {
+    let threshold = mtime(dst);
+    let meta = t!(fs::metadata(src));
+    if meta.is_dir() {
+        dir_up_to_date(src, &threshold)
+    } else {
+        FileTime::from_last_modification_time(&meta) <= threshold
+    }
+}
+
+fn dir_up_to_date(src: &Path, threshold: &FileTime) -> bool {
+    t!(fs::read_dir(src)).map(|e| t!(e)).all(|e| {
+        let meta = t!(e.metadata());
+        if meta.is_dir() {
+            dir_up_to_date(&e.path(), threshold)
+        } else {
+            FileTime::from_last_modification_time(&meta) < *threshold
+        }
+    })
+}
+
+/// Returns the environment variable which the dynamic library lookup path
+/// resides in for this platform.
+pub fn dylib_path_var() -> &'static str {
+    if cfg!(target_os = "windows") {
+        "PATH"
+    } else if cfg!(target_os = "macos") {
+        "DYLD_LIBRARY_PATH"
+    } else {
+        "LD_LIBRARY_PATH"
+    }
+}
+
+/// Parses the `dylib_path_var()` environment variable, returning a list of
+/// paths that are members of this lookup path.
+pub fn dylib_path() -> Vec<PathBuf> {
+    env::split_paths(&env::var_os(dylib_path_var()).unwrap_or(OsString::new()))
+        .collect()
+}