Rollup of 10 pull requests

src/bootstrap/bin/rustc.rs

@@ -68,6 +68,7 @@ fn main() {
     };
     let stage = env::var("RUSTC_STAGE").expect("RUSTC_STAGE was not set");
     let sysroot = env::var_os("RUSTC_SYSROOT").expect("RUSTC_SYSROOT was not set");
+    let mut on_fail = env::var_os("RUSTC_ON_FAIL").map(|of| Command::new(of));
 
     let rustc = env::var_os(rustc).unwrap_or_else(|| panic!("{:?} was not set", rustc));
     let libdir = env::var_os(libdir).unwrap_or_else(|| panic!("{:?} was not set", libdir));
@@ -217,9 +218,20 @@ fn main() {
     }
 
     // Actually run the compiler!
-    std::process::exit(match exec_cmd(&mut cmd) {
-        Ok(s) => s.code().unwrap_or(0xfe),
-        Err(e) => panic!("\n\nfailed to run {:?}: {}\n\n", cmd, e),
+    std::process::exit(if let Some(ref mut on_fail) = on_fail {
+        match cmd.status() {
+            Ok(s) if s.success() => 0,
+            _ => {
+                println!("\nDid not run successfully:\n{:?}\n-------------", cmd);
+                exec_cmd(on_fail).expect("could not run the backup command");
+                1
+            }
+        }
+    } else {
+        std::process::exit(match exec_cmd(&mut cmd) {
+            Ok(s) => s.code().unwrap_or(0xfe),
+            Err(e) => panic!("\n\nfailed to run {:?}: {}\n\n", cmd, e),
+        })
     })
 }
 

src/bootstrap/bootstrap.py

@@ -472,6 +472,8 @@ def build_triple(self):
             ostype += 'abi64'
         elif cputype in {'powerpc', 'ppc', 'ppc64'}:
             cputype = 'powerpc'
+        elif cputype == 'sparcv9':
+            pass
         elif cputype in {'amd64', 'x86_64', 'x86-64', 'x64'}:
             cputype = 'x86_64'
         else:

src/bootstrap/compile.rs

@@ -21,7 +21,7 @@ use std::fs::{self, File};
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-use build_helper::{output, mtime};
+use build_helper::{output, mtime, up_to_date};
 use filetime::FileTime;
 
 use util::{exe, libdir, is_dylib, copy};
@@ -132,21 +132,29 @@ pub fn build_startup_objects(build: &Build, for_compiler: &Compiler, target: &st
 
     let compiler = Compiler::new(0, &build.config.build);
     let compiler_path = build.compiler_path(&compiler);
-    let into = build.sysroot_libdir(for_compiler, target);
-    t!(fs::create_dir_all(&into));
-
-    for file in t!(fs::read_dir(build.src.join("src/rtstartup"))) {
-        let file = t!(file);
-        let mut cmd = Command::new(&compiler_path);
-        build.run(cmd.env("RUSTC_BOOTSTRAP", "1")
-                     .arg("--target").arg(target)
-                     .arg("--emit=obj")
-                     .arg("--out-dir").arg(&into)
-                     .arg(file.path()));
+    let src_dir = &build.src.join("src/rtstartup");
+    let dst_dir = &build.native_dir(target).join("rtstartup");
+    let sysroot_dir = &build.sysroot_libdir(for_compiler, target);
+    t!(fs::create_dir_all(dst_dir));
+    t!(fs::create_dir_all(sysroot_dir));
+
+    for file in &["rsbegin", "rsend"] {
+        let src_file = &src_dir.join(file.to_string() + ".rs");
+        let dst_file = &dst_dir.join(file.to_string() + ".o");
+        if !up_to_date(src_file, dst_file) {
+            let mut cmd = Command::new(&compiler_path);
+            build.run(cmd.env("RUSTC_BOOTSTRAP", "1")
+                        .arg("--target").arg(target)
+                        .arg("--emit=obj")
+                        .arg("--out-dir").arg(dst_dir)
+                        .arg(src_file));
+        }
+
+        copy(dst_file, &sysroot_dir.join(file.to_string() + ".o"));
     }
 
     for obj in ["crt2.o", "dllcrt2.o"].iter() {
-        copy(&compiler_file(build.cc(target), obj), &into.join(obj));
+        copy(&compiler_file(build.cc(target), obj), &sysroot_dir.join(obj));
     }
 }
 

src/bootstrap/flags.rs

@@ -28,6 +28,7 @@ use step;
 /// Deserialized version of all flags for this compile.
 pub struct Flags {
     pub verbose: usize, // verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose
+    pub on_fail: Option<String>,
     pub stage: Option<u32>,
     pub keep_stage: Option<u32>,
     pub build: String,
@@ -81,6 +82,7 @@ impl Flags {
         opts.optopt("", "build", "build target of the stage0 compiler", "BUILD");
         opts.optmulti("", "host", "host targets to build", "HOST");
         opts.optmulti("", "target", "target targets to build", "TARGET");
+        opts.optopt("", "on-fail", "command to run on failure", "CMD");
         opts.optopt("", "stage", "stage to build", "N");
         opts.optopt("", "keep-stage", "stage to keep without recompiling", "N");
         opts.optopt("", "src", "path to the root of the rust checkout", "DIR");
@@ -283,6 +285,7 @@ To learn more about a subcommand, run `./x.py <command> -h`
         Flags {
             verbose: m.opt_count("v"),
             stage: stage,
+            on_fail: m.opt_str("on-fail"),
             keep_stage: m.opt_str("keep-stage").map(|j| j.parse().unwrap()),
             build: m.opt_str("build").unwrap_or_else(|| {
                 env::var("BUILD").unwrap()

src/bootstrap/lib.rs

@@ -499,6 +499,10 @@ impl Build {
             cargo.env("RUSTC_INCREMENTAL", incr_dir);
         }
 
+        if let Some(ref on_fail) = self.flags.on_fail {
+            cargo.env("RUSTC_ON_FAIL", on_fail);
+        }
+
         let verbose = cmp::max(self.config.verbose, self.flags.verbose);
         cargo.env("RUSTC_VERBOSE", format!("{}", verbose));
 

src/doc/nomicon/src/exception-safety.md

@@ -93,7 +93,7 @@ uselessly. We would rather have the following:
 ```text
 bubble_up(heap, index):
     let elem = heap[index]
-    while index != 0 && element < heap[parent(index)]:
+    while index != 0 && elem < heap[parent(index)]:
         heap[index] = heap[parent(index)]
         index = parent(index)
     heap[index] = elem
@@ -137,7 +137,7 @@ If Rust had `try` and `finally` like in Java, we could do the following:
 bubble_up(heap, index):
     let elem = heap[index]
     try:
-        while index != 0 && element < heap[parent(index)]:
+        while index != 0 && elem < heap[parent(index)]:
             heap[index] = heap[parent(index)]
             index = parent(index)
     finally:

src/libcollections/string.rs

@@ -1629,6 +1629,43 @@ impl hash::Hash for String {
     }
 }
 
+/// Implements the `+` operator for concatenating two strings.
+///
+/// This consumes the `String` on the left-hand side and re-uses its buffer (growing it if
+/// necessary). This is done to avoid allocating a new `String` and copying the entire contents on
+/// every operation, which would lead to `O(n^2)` running time when building an `n`-byte string by
+/// repeated concatenation.
+///
+/// The string on the right-hand side is only borrowed; its contents are copied into the returned
+/// `String`.
+///
+/// # Examples
+///
+/// Concatenating two `String`s takes the first by value and borrows the second:
+///
+/// ```
+/// let a = String::from("hello");
+/// let b = String::from(" world");
+/// let c = a + &b;
+/// // `a` is moved and can no longer be used here.
+/// ```
+///
+/// If you want to keep using the first `String`, you can clone it and append to the clone instead:
+///
+/// ```
+/// let a = String::from("hello");
+/// let b = String::from(" world");
+/// let c = a.clone() + &b;
+/// // `a` is still valid here.
+/// ```
+///
+/// Concatenating `&str` slices can be done by converting the first to a `String`:
+///
+/// ```
+/// let a = "hello";
+/// let b = " world";
+/// let c = a.to_string() + b;
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a> Add<&'a str> for String {
     type Output = String;
@@ -1640,6 +1677,11 @@ impl<'a> Add<&'a str> for String {
     }
 }
 
+/// Implements the `+=` operator for appending to a `String`.
+///
+/// This has the same behavior as the [`push_str()`] method.
+///
+/// [`push_str()`]: struct.String.html#method.push_str
 #[stable(feature = "stringaddassign", since = "1.12.0")]
 impl<'a> AddAssign<&'a str> for String {
     #[inline]

src/libcollections/vec.rs

@@ -1776,6 +1776,7 @@ array_impls! {
     30 31 32
 }
 
+/// Implements comparison of vectors, lexicographically.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: PartialOrd> PartialOrd for Vec<T> {
     #[inline]
@@ -1787,6 +1788,7 @@ impl<T: PartialOrd> PartialOrd for Vec<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Eq> Eq for Vec<T> {}
 
+/// Implements ordering of vectors, lexicographically.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Ord> Ord for Vec<T> {
     #[inline]

src/libcompiler_builtins/build.rs

@@ -92,7 +92,15 @@ fn main() {
         // compiler-rt's build system already
         cfg.flag("-fno-builtin");
         cfg.flag("-fvisibility=hidden");
-        cfg.flag("-fomit-frame-pointer");
+        // Accepted practice on Solaris is to never omit frame pointer so that
+        // system observability tools work as expected.  In addition, at least
+        // on Solaris, -fomit-frame-pointer on sparcv9 appears to generate
+        // references to data outside of the current stack frame.  A search of
+        // the gcc bug database provides a variety of issues surrounding
+        // -fomit-frame-pointer on non-x86 platforms.
+        if !target.contains("solaris") && !target.contains("sparc") {
+            cfg.flag("-fomit-frame-pointer");
+        }
         cfg.flag("-ffreestanding");
         cfg.define("VISIBILITY_HIDDEN", None);
     }

src/libcore/slice.rs

@@ -2202,13 +2202,15 @@ impl<A, B> PartialEq<[B]> for [A] where A: PartialEq<B> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Eq> Eq for [T] {}
 
+/// Implements comparison of vectors lexicographically.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Ord> Ord for [T] {
     fn cmp(&self, other: &[T]) -> Ordering {
         SliceOrd::compare(self, other)
     }
 }
 
+/// Implements comparison of vectors lexicographically.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: PartialOrd> PartialOrd for [T] {
     fn partial_cmp(&self, other: &[T]) -> Option<Ordering> {

src/libcore/str/mod.rs

@@ -1366,6 +1366,13 @@ mod traits {
     use ops;
     use str::eq_slice;
 
+    /// Implements ordering of strings.
+    ///
+    /// Strings are ordered  lexicographically by their byte values.  This orders Unicode code
+    /// points based on their positions in the code charts.  This is not necessarily the same as
+    /// "alphabetical" order, which varies by language and locale.  Sorting strings according to
+    /// culturally-accepted standards requires locale-specific data that is outside the scope of
+    /// the `str` type.
     #[stable(feature = "rust1", since = "1.0.0")]
     impl Ord for str {
         #[inline]
@@ -1387,6 +1394,13 @@ mod traits {
     #[stable(feature = "rust1", since = "1.0.0")]
     impl Eq for str {}
 
+    /// Implements comparison operations on strings.
+    ///
+    /// Strings are compared lexicographically by their byte values.  This compares Unicode code
+    /// points based on their positions in the code charts.  This is not necessarily the same as
+    /// "alphabetical" order, which varies by language and locale.  Comparing strings according to
+    /// culturally-accepted standards requires locale-specific data that is outside the scope of
+    /// the `str` type.
     #[stable(feature = "rust1", since = "1.0.0")]
     impl PartialOrd for str {
         #[inline]

src/librustc/ty/inhabitedness/mod.rs

@@ -187,7 +187,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
                         //      which contains a Foo<((T, T), (T, T))>
                         //      which contains a Foo<(((T, T), (T, T)), ((T, T), (T, T)))>
                         //      etc.
-                        let error = format!("reached recursion limit while checking
+                        let error = format!("reached recursion limit while checking \
                                              inhabitedness of `{}`", self);
                         tcx.sess.fatal(&error);
                     }

src/librustc_back/target/mod.rs

@@ -200,6 +200,7 @@ supported_targets! {
     ("armv7s-apple-ios", armv7s_apple_ios),
 
     ("x86_64-sun-solaris", x86_64_sun_solaris),
+    ("sparcv9-sun-solaris", sparcv9_sun_solaris),
 
     ("x86_64-pc-windows-gnu", x86_64_pc_windows_gnu),
     ("i686-pc-windows-gnu", i686_pc_windows_gnu),

src/librustc_back/target/sparcv9_sun_solaris.rs

@@ -0,0 +1,35 @@
+// Copyright 2016 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.
+
+use target::{Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::solaris_base::opts();
+    base.pre_link_args.push("-m64".to_string());
+    // llvm calls this "v9"
+    base.cpu = "v9".to_string();
+    base.max_atomic_width = Some(64);
+
+    Ok(Target {
+        llvm_target: "sparcv9-sun-solaris".to_string(),
+        target_endian: "big".to_string(),
+        target_pointer_width: "64".to_string(),
+        data_layout: "E-m:e-i64:64-n32:64-S128".to_string(),
+        // Use "sparc64" instead of "sparcv9" here, since the former is already
+        // used widely in the source base.  If we ever needed ABI
+        // differentiation from the sparc64, we could, but that would probably
+        // just be confusing.
+        arch: "sparc64".to_string(),
+        target_os: "solaris".to_string(),
+        target_env: "".to_string(),
+        target_vendor: "sun".to_string(),
+        options: base,
+    })
+}

src/libstd/build.rs

@@ -59,6 +59,10 @@ fn main() {
         println!("cargo:rustc-link-lib=userenv");
         println!("cargo:rustc-link-lib=shell32");
     } else if target.contains("fuchsia") {
+        // use system-provided libbacktrace
+        if cfg!(feature = "backtrace") {
+            println!("cargo:rustc-link-lib=backtrace");
+        }
         println!("cargo:rustc-link-lib=magenta");
         println!("cargo:rustc-link-lib=mxio");
         println!("cargo:rustc-link-lib=launchpad"); // for std::process