Rollup of 8 pull requests

.gitmodules

@@ -25,4 +25,4 @@
 	url = https://github.com/rust-lang-nursery/reference.git
 [submodule "book"]
 	path = src/doc/book
-	url = https://github.com/rust-lang/book
+	url = https://github.com/rust-lang/book.git

src/bootstrap/dist.rs

@@ -433,29 +433,32 @@ pub fn rust_src(build: &Build) {
         copy(&build.src.join(item), &dst_src.join(item));
     }
 
-    // Get cargo-vendor installed, if it isn't already.
-    let mut has_cargo_vendor = false;
-    let mut cmd = Command::new(&build.cargo);
-    for line in output(cmd.arg("install").arg("--list")).lines() {
-        has_cargo_vendor |= line.starts_with("cargo-vendor ");
-    }
-    if !has_cargo_vendor {
+    // If we're building from git sources, we need to vendor a complete distribution.
+    if build.src_is_git {
+        // Get cargo-vendor installed, if it isn't already.
+        let mut has_cargo_vendor = false;
+        let mut cmd = Command::new(&build.cargo);
+        for line in output(cmd.arg("install").arg("--list")).lines() {
+            has_cargo_vendor |= line.starts_with("cargo-vendor ");
+        }
+        if !has_cargo_vendor {
+            let mut cmd = Command::new(&build.cargo);
+            cmd.arg("install")
+               .arg("--force")
+               .arg("--debug")
+               .arg("--vers").arg(CARGO_VENDOR_VERSION)
+               .arg("cargo-vendor")
+               .env("RUSTC", &build.rustc);
+            build.run(&mut cmd);
+        }
+
+        // Vendor all Cargo dependencies
         let mut cmd = Command::new(&build.cargo);
-        cmd.arg("install")
-           .arg("--force")
-           .arg("--debug")
-           .arg("--vers").arg(CARGO_VENDOR_VERSION)
-           .arg("cargo-vendor")
-           .env("RUSTC", &build.rustc);
+        cmd.arg("vendor")
+           .current_dir(&dst_src.join("src"));
         build.run(&mut cmd);
     }
 
-    // Vendor all Cargo dependencies
-    let mut cmd = Command::new(&build.cargo);
-    cmd.arg("vendor")
-       .current_dir(&dst_src.join("src"));
-    build.run(&mut cmd);
-
     // Create source tarball in rust-installer format
     let mut cmd = Command::new(SH_CMD);
     cmd.arg(sanitize_sh(&build.src.join("src/rust-installer/gen-installer.sh")))

src/bootstrap/lib.rs

@@ -162,6 +162,7 @@ pub struct Build {
     cxx: HashMap<String, gcc::Tool>,
     crates: HashMap<String, Crate>,
     is_sudo: bool,
+    src_is_git: bool,
 }
 
 #[derive(Debug)]
@@ -233,6 +234,7 @@ impl Build {
         };
         let rust_info = channel::GitInfo::new(&src);
         let cargo_info = channel::GitInfo::new(&src.join("cargo"));
+        let src_is_git = src.join(".git").exists();
 
         Build {
             flags: flags,
@@ -251,6 +253,7 @@ impl Build {
             lldb_version: None,
             lldb_python_dir: None,
             is_sudo: is_sudo,
+            src_is_git: src_is_git,
         }
     }
 
@@ -307,10 +310,7 @@ impl Build {
             OutOfSync,
         }
 
-        if !self.config.submodules {
-            return
-        }
-        if fs::metadata(self.src.join(".git")).is_err() {
+        if !self.src_is_git || !self.config.submodules {
             return
         }
         let git = || {

src/bootstrap/sanity.rs

@@ -65,7 +65,7 @@ pub fn check(build: &mut Build) {
 
     // If we've got a git directory we're gona need git to update
     // submodules and learn about various other aspects.
-    if fs::metadata(build.src.join(".git")).is_ok() {
+    if build.src_is_git {
         need_cmd("git".as_ref());
     }
 

src/ci/docker/dist-i586-gnu-i686-musl/build-musl.sh

@@ -15,11 +15,14 @@ set -ex
 export CFLAGS="-fPIC -Wa,-mrelax-relocations=no"
 export CXXFLAGS="-Wa,-mrelax-relocations=no"
 
-MUSL=musl-1.1.14
+MUSL=musl-1.1.16
 curl https://www.musl-libc.org/releases/$MUSL.tar.gz | tar xzf -
 cd $MUSL
-CFLAGS="$CFLAGS -m32" ./configure --prefix=/musl-i686 --disable-shared --target=i686
-make -j10
+CC=gcc \
+  CFLAGS="$CFLAGS -m32" \
+  ./configure --prefix=/musl-i686 --disable-shared \
+    --target=i686
+make AR=ar RANLIB=ranlib -j10
 make install
 cd ..
 

src/ci/docker/dist-x86_64-musl/build-musl.sh

@@ -15,7 +15,7 @@ set -ex
 export CFLAGS="-fPIC -Wa,-mrelax-relocations=no"
 export CXXFLAGS="-Wa,-mrelax-relocations=no"
 
-MUSL=musl-1.1.14
+MUSL=musl-1.1.16
 curl https://www.musl-libc.org/releases/$MUSL.tar.gz | tar xzf -
 cd $MUSL
 ./configure --prefix=/musl-x86_64 --disable-shared

src/doc/unstable-book/src/SUMMARY.md

@@ -205,6 +205,7 @@
 - [unwind_attributes](unwind-attributes.md)
 - [update_panic_count](update-panic-count.md)
 - [use_extern_macros](use-extern-macros.md)
+- [used](used.md)
 - [utf8_error_error_len](utf8-error-error-len.md)
 - [vec_remove_item](vec-remove-item.md)
 - [windows_c](windows-c.md)

src/doc/unstable-book/src/used.md

@@ -0,0 +1,153 @@
+# `used`
+
+The tracking issue for this feature
+is: [40289](https://github.com/rust-lang/rust/issues/40289).
+
+------------------------
+
+The `#[used]` attribute can be applied to `static` variables to prevent the Rust
+compiler from optimizing them away even if they appear to be unused by the crate
+(appear to be "dead code").
+
+``` rust
+#![feature(used)]
+
+#[used]
+static FOO: i32 = 1;
+
+static BAR: i32 = 2;
+
+fn main() {}
+```
+
+If you compile this program into an object file, you'll see that `FOO` makes it
+to the object file but `BAR` doesn't. Neither static variable is used by the
+program.
+
+``` text
+$ rustc -C opt-level=3 --emit=obj used.rs
+
+$ nm -C used.o
+0000000000000000 T main
+                 U std::rt::lang_start
+0000000000000000 r used::FOO
+0000000000000000 t used::main
+```
+
+Note that the *linker* knows nothing about the `#[used]` attribute and will
+remove `#[used]` symbols if they are not referenced by other parts of the
+program:
+
+``` text
+$ rustc -C opt-level=3 used.rs
+
+$ nm -C used | grep FOO
+```
+
+"This doesn't sound too useful then!" you may think but keep reading.
+
+To preserve the symbols all the way to the final binary, you'll need the
+cooperation of the linker. Here's one example:
+
+The ELF standard defines two special sections, `.init_array` and
+`.pre_init_array`, that may contain function pointers which will be executed
+*before* the `main` function is invoked. The linker will preserve symbols placed
+in these sections (at least when linking programs that target the `*-*-linux-*`
+targets).
+
+``` rust
+#![feature(used)]
+
+extern "C" fn before_main() {
+    println!("Hello, world!");
+}
+
+#[link_section = ".init_array"]
+#[used]
+static INIT_ARRAY: [extern "C" fn(); 1] = [before_main];
+
+fn main() {}
+```
+
+So, `#[used]` and `#[link_section]` can be combined to obtain "life before
+main".
+
+``` text
+$ rustc -C opt-level=3 before-main.rs
+
+$ ./before-main
+Hello, world!
+```
+
+Another example: ARM Cortex-M microcontrollers need their reset handler, a
+pointer to the function that will executed right after the microcontroller is
+turned on, to be placed near the start of their FLASH memory to boot properly.
+
+This condition can be met using `#[used]` and `#[link_section]` plus a linker
+script.
+
+``` rust,ignore
+#![feature(lang_items)]
+#![feature(used)]
+#![no_main]
+#![no_std]
+
+extern "C" fn reset_handler() -> ! {
+    loop {}
+}
+
+#[link_section = ".reset_handler"]
+#[used]
+static RESET_HANDLER: extern "C" fn() -> ! = reset_handler;
+
+#[lang = "panic_fmt"]
+fn panic_fmt() {}
+```
+
+``` text
+MEMORY
+{
+  FLASH : ORIGIN = 0x08000000, LENGTH = 128K
+  RAM : ORIGIN = 0x20000000, LENGTH = 20K
+}
+
+SECTIONS
+{
+  .text ORIGIN(FLASH) :
+  {
+    /* Vector table */
+    LONG(ORIGIN(RAM) + LENGTH(RAM)); /* initial SP value */
+    KEEP(*(.reset_handler));
+
+    /* Omitted: The rest of the vector table */
+
+    *(.text.*);
+  } > FLASH
+
+  /DISCARD/ :
+  {
+    /* Unused unwinding stuff */
+    *(.ARM.exidx.*)
+  }
+}
+```
+
+``` text
+$ xargo rustc --target thumbv7m-none-eabi --release -- \
+    -C link-arg=-Tlink.x -C link-arg=-nostartfiles
+
+$ arm-none-eabi-objdump -Cd target/thumbv7m-none-eabi/release/app
+./target/thumbv7m-none-eabi/release/app:     file format elf32-littlearm
+
+
+Disassembly of section .text:
+
+08000000 <app::RESET_HANDLER-0x4>:
+ 8000000:       20005000        .word   0x20005000
+
+08000004 <app::RESET_HANDLER>:
+ 8000004:       08000009                                ....
+
+08000008 <app::reset_handler>:
+ 8000008:       e7fe            b.n     8000008 <app::reset_handler>
+```

src/libcollections/vec.rs

@@ -1346,7 +1346,7 @@ impl<T: PartialEq> Vec<T> {
     /// # Examples
     ///
     /// ```
-    ///# #![feature(vec_remove_item)]
+    /// # #![feature(vec_remove_item)]
     /// let mut vec = vec![1, 2, 3, 1];
     ///
     /// vec.remove_item(&1);

src/libcore/sync/atomic.rs

@@ -153,8 +153,9 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 /// Rust's memory orderings are [the same as
 /// LLVM's](http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations).
 ///
-/// For more information see the [nomicon][1].
-/// [1]: ../../../nomicon/atomics.html
+/// For more information see the [nomicon].
+///
+/// [nomicon]: ../../../nomicon/atomics.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Copy, Clone, Debug)]
 pub enum Ordering {

src/librustc/hir/map/definitions.rs

@@ -394,6 +394,10 @@ impl Definitions {
         }
     }
 
+    pub fn node_to_hir_id(&self, node_id: ast::NodeId) -> hir::HirId {
+        self.node_to_hir_id[node_id]
+    }
+
     /// Add a definition with a parent definition.
     pub fn create_def_with_parent(&mut self,
                                   parent: Option<DefIndex>,