Auto merge of #36818 - jonathandturner:rollup, r=jonathandturner

Rollup of 12 pull requests

- Successful merges: #35286, #35892, #36460, #36704, #36741, #36760, #36787, #36789, #36794, #36803, #36811, #36813
- Failed merges:

configure

@@ -645,7 +645,6 @@ valopt datadir "${CFG_PREFIX}/share" "install data"
 valopt infodir "${CFG_PREFIX}/share/info" "install additional info"
 valopt llvm-root "" "set LLVM root"
 valopt python "" "set path to python"
-valopt nodejs "" "set path to nodejs"
 valopt jemalloc-root "" "set directory where libjemalloc_pic.a is located"
 valopt build "${DEFAULT_BUILD}" "GNUs ./configure syntax LLVM build triple"
 valopt android-cross-path "" "Android NDK standalone path (deprecated)"
@@ -762,9 +761,6 @@ if [ $(echo $python_version | grep -c '^Python 2\.7') -ne 1 ]; then
     err "Found $python_version, but Python 2.7 is required"
 fi
 
-# Checking for node, but not required
-probe CFG_NODEJS nodejs node
-
 # If we have no git directory then we are probably a tarball distribution
 # and shouldn't attempt to load submodules
 if [ ! -e ${CFG_SRC_DIR}.git ]

src/bootstrap/bin/rustc.rs

@@ -104,8 +104,7 @@ fn main() {
         let is_panic_abort = args.windows(2).any(|a| {
             &*a[0] == "--crate-name" && &*a[1] == "panic_abort"
         });
-        // FIXME(stage0): remove this `stage != "0"` condition
-        if is_panic_abort && stage != "0" {
+        if is_panic_abort {
             cmd.arg("-C").arg("panic=abort");
         }
 

src/bootstrap/compile.rs

@@ -25,7 +25,7 @@ use std::process::Command;
 use build_helper::output;
 use filetime::FileTime;
 
-use util::{exe, staticlib, libdir, mtime, is_dylib, copy};
+use util::{exe, libdir, mtime, is_dylib, copy};
 use {Build, Compiler, Mode};
 
 /// Build the standard library.
@@ -40,20 +40,6 @@ pub fn std<'a>(build: &'a Build, target: &str, compiler: &Compiler<'a>) {
     let libdir = build.sysroot_libdir(compiler, target);
     let _ = fs::remove_dir_all(&libdir);
     t!(fs::create_dir_all(&libdir));
-    // FIXME(stage0) remove this `if` after the next snapshot
-    // The stage0 compiler still passes the `-lcompiler-rt` flag to the linker but now `bootstrap`
-    // never builds a `libcopmiler-rt.a`! We'll fill the hole by simply copying stage0's
-    // `libcompiler-rt.a` to where the stage1's one is expected (though we could as well just use
-    // an empty `.a` archive). Note that the symbols of that stage0 `libcompiler-rt.a` won't make
-    // it to the final binary because now `libcore.rlib` also contains the symbols that
-    // `libcompiler-rt.a` provides. Since that rlib appears first in the linker arguments, its
-    // symbols are used instead of `libcompiler-rt.a`'s.
-    if compiler.stage == 0 {
-        let rtlib = &staticlib("compiler-rt", target);
-        let src = build.rustc.parent().unwrap().parent().unwrap().join("lib").join("rustlib")
-            .join(target).join("lib").join(rtlib);
-        copy(&src, &libdir.join(rtlib));
-    }
 
     // Some platforms have startup objects that may be required to produce the
     // libstd dynamic library, for example.

src/bootstrap/config.rs

@@ -396,9 +396,6 @@ impl Config {
                     self.rustc = Some(PathBuf::from(value).join("bin/rustc"));
                     self.cargo = Some(PathBuf::from(value).join("bin/cargo"));
                 }
-                "CFG_NODEJS" if value.len() > 0 => {
-                    self.nodejs = Some(PathBuf::from(value));
-                }
                 _ => {}
             }
         }

src/bootstrap/sanity.rs

@@ -40,17 +40,23 @@ pub fn check(build: &mut Build) {
             panic!("PATH contains invalid character '\"'");
         }
     }
-    let mut need_cmd = |cmd: &OsStr| {
-        if !checked.insert(cmd.to_owned()) {
-            return
-        }
+    let have_cmd = |cmd: &OsStr| {
         for path in env::split_paths(&path).map(|p| p.join(cmd)) {
             if fs::metadata(&path).is_ok() ||
                fs::metadata(path.with_extension("exe")).is_ok() {
-                return
+                return Some(path);
             }
         }
-        panic!("\n\ncouldn't find required command: {:?}\n\n", cmd);
+        return None;
+    };
+
+    let mut need_cmd = |cmd: &OsStr| {
+        if !checked.insert(cmd.to_owned()) {
+            return
+        }
+        if have_cmd(cmd).is_none() {
+            panic!("\n\ncouldn't find required command: {:?}\n\n", cmd);
+        }
     };
 
     // If we've got a git directory we're gona need git to update
@@ -75,8 +81,13 @@ pub fn check(build: &mut Build) {
 
     need_cmd("python".as_ref());
 
-    // If a manual nodejs was added to the config,
-    // of if a nodejs install is detected through config, use it.
+    // Look for the nodejs command, needed for emscripten testing
+    if let Some(node) = have_cmd("node".as_ref()) {
+        build.config.nodejs = Some(node);
+    } else if let Some(node) = have_cmd("nodejs".as_ref()) {
+        build.config.nodejs = Some(node);
+    }
+
     if let Some(ref s) = build.config.nodejs {
         need_cmd(s.as_ref());
     }

src/doc/book/syntax-index.md

@@ -61,7 +61,6 @@
 * `-` (`- expr`): arithmetic negation.  Overloadable (`Neg`).
 * `-=` (`var -= expr`): arithmetic subtraction & assignment. Overloadable (`SubAssign`).
 * `->` (`fn(…) -> type`, `|…| -> type`): function and closure return type.  See [Functions], [Closures].
-* `-> !` (`fn(…) -> !`, `|…| -> !`): diverging function or closure. See [Diverging Functions].
 * `.` (`expr.ident`): member access.  See [Structs], [Method Syntax].
 * `..` (`..`, `expr..`, `..expr`, `expr..expr`): right-exclusive range literal.
 * `..` (`..expr`): struct literal update syntax.  See [Structs (Update syntax)].
@@ -159,6 +158,10 @@
 * `/*!…*/`: inner block doc comment.  See [Comments].
 * `/**…*/`: outer block doc comment.  See [Comments].
 
+<!-- Special types -->
+
+* `!`: always empty Never type.  See [Diverging Functions].
+
 <!-- Various things involving parens and tuples -->
 
 * `()`: empty tuple (*a.k.a.* unit), both literal and type.

src/doc/grammar.md

@@ -764,6 +764,13 @@ bound-list := bound | bound '+' bound-list
 bound := path | lifetime
 ```
 
+### Never type
+An empty type
+
+```antlr
+never_type : "!" ;
+```
+
 ### Object types
 
 **FIXME:** grammar?

src/liballoc/arc.rs

@@ -127,7 +127,6 @@ const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 /// }
 /// ```
 
-#[cfg_attr(stage0, unsafe_no_drop_flag)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Arc<T: ?Sized> {
     ptr: Shared<ArcInner<T>>,
@@ -153,7 +152,6 @@ impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Arc<U>> for Arc<T> {}
 /// nodes behind strong `Arc<T>` pointers, and then storing the parent pointers
 /// as `Weak<T>` pointers.
 
-#[cfg_attr(stage0, unsafe_no_drop_flag)]
 #[stable(feature = "arc_weak", since = "1.4.0")]
 pub struct Weak<T: ?Sized> {
     ptr: Shared<ArcInner<T>>,

src/liballoc/lib.rs

@@ -88,7 +88,6 @@
 #![feature(staged_api)]
 #![feature(unboxed_closures)]
 #![feature(unique)]
-#![cfg_attr(stage0, feature(unsafe_no_drop_flag))]
 #![feature(unsize)]
 
 #![cfg_attr(not(test), feature(fused, fn_traits, placement_new_protocol))]

src/liballoc/raw_vec.rs

@@ -44,7 +44,6 @@ use core::cmp;
 /// `shrink_to_fit`, and `from_box` will actually set RawVec's private capacity
 /// field. This allows zero-sized types to not be special-cased by consumers of
 /// this type.
-#[cfg_attr(stage0, unsafe_no_drop_flag)]
 pub struct RawVec<T> {
     ptr: Unique<T>,
     cap: usize,

src/liballoc/rc.rs

@@ -252,7 +252,6 @@ struct RcBox<T: ?Sized> {
 /// that you have to call them as e.g. `Rc::get_mut(&value)` instead of
 /// `value.get_mut()`.  This avoids conflicts with methods of the inner
 /// type `T`.
-#[cfg_attr(stage0, unsafe_no_drop_flag)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Rc<T: ?Sized> {
     ptr: Shared<RcBox<T>>,
@@ -873,7 +872,6 @@ impl<T> From<T> for Rc<T> {
 ///
 /// [rc]: struct.Rc.html
 /// [downgrade]: struct.Rc.html#method.downgrade
-#[cfg_attr(stage0, unsafe_no_drop_flag)]
 #[stable(feature = "rc_weak", since = "1.4.0")]
 pub struct Weak<T: ?Sized> {
     ptr: Shared<RcBox<T>>,

src/libcollections/lib.rs

@@ -52,7 +52,6 @@
 #![feature(step_by)]
 #![feature(unicode)]
 #![feature(unique)]
-#![cfg_attr(stage0, feature(unsafe_no_drop_flag))]
 #![cfg_attr(test, feature(rand, test))]
 
 #![no_std]

src/libcollections/macros.rs

@@ -68,7 +68,9 @@ macro_rules! vec {
 }
 
 /// Use the syntax described in `std::fmt` to create a value of type `String`.
-/// See `std::fmt` for more information.
+/// See [`std::fmt`][fmt] for more information.
+///
+/// [fmt]: ../std/fmt/index.html
 ///
 /// # Examples
 ///

src/libcollections/vec.rs

@@ -268,7 +268,6 @@ use super::range::RangeArgument;
 /// Vec does not currently guarantee the order in which elements are dropped
 /// (the order has changed in the past, and may change again).
 ///
-#[cfg_attr(stage0, unsafe_no_drop_flag)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Vec<T> {
     buf: RawVec<T>,

src/libcompiler_builtins/lib.rs

@@ -8,9 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![cfg_attr(not(stage0), feature(compiler_builtins))]
+#![feature(compiler_builtins)]
 #![no_std]
-#![cfg_attr(not(stage0), compiler_builtins)]
+#![compiler_builtins]
 #![unstable(feature = "compiler_builtins_lib",
             reason = "internal implementation detail of rustc right now",
             issue = "0")]

src/libcore/clone.rs

@@ -129,13 +129,6 @@ pub struct AssertParamIsClone<T: Clone + ?Sized> { _field: ::marker::PhantomData
            reason = "deriving hack, should not be public",
            issue = "0")]
 pub struct AssertParamIsCopy<T: Copy + ?Sized> { _field: ::marker::PhantomData<T> }
-#[cfg(stage0)]
-#[doc(hidden)]
-#[inline(always)]
-#[unstable(feature = "derive_clone_copy",
-           reason = "deriving hack, should not be public",
-           issue = "0")]
-pub fn assert_receiver_is_clone<T: Clone + ?Sized>(_: &T) {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: ?Sized> Clone for &'a T {

src/libcore/intrinsics.rs

@@ -194,14 +194,12 @@ extern "rust-intrinsic" {
     /// own, or if it does not enable any significant optimizations.
     pub fn assume(b: bool);
 
-    #[cfg(not(stage0))]
     /// Hints to the compiler that branch condition is likely to be true.
     /// Returns the value passed to it.
     ///
     /// Any use other than with `if` statements will probably not have an effect.
     pub fn likely(b: bool) -> bool;
 
-    #[cfg(not(stage0))]
     /// Hints to the compiler that branch condition is likely to be false.
     /// Returns the value passed to it.
     ///

src/librustc/middle/cstore.rs

@@ -32,7 +32,6 @@ use ty::{self, Ty, TyCtxt};
 use mir::repr::Mir;
 use mir::mir_map::MirMap;
 use session::Session;
-use session::config::PanicStrategy;
 use session::search_paths::PathKind;
 use util::nodemap::{NodeSet, DefIdMap};
 use std::path::PathBuf;
@@ -46,6 +45,7 @@ use syntax_pos::Span;
 use rustc_back::target::Target;
 use hir;
 use hir::intravisit::Visitor;
+use rustc_back::PanicStrategy;
 
 pub use self::NativeLibraryKind::{NativeStatic, NativeFramework, NativeUnknown};
 

src/librustc/middle/dependency_format.rs

@@ -64,9 +64,10 @@
 use hir::def_id::CrateNum;
 
 use session;
-use session::config::{self, PanicStrategy};
+use session::config;
 use middle::cstore::LinkagePreference::{self, RequireStatic, RequireDynamic};
 use util::nodemap::FnvHashMap;
+use rustc_back::PanicStrategy;
 
 /// A list of dependencies for a certain crate type.
 ///
@@ -357,7 +358,7 @@ fn verify_ok(sess: &session::Session, list: &[Linkage]) {
     // only one, but we perform validation here that all the panic strategy
     // compilation modes for the whole DAG are valid.
     if let Some((cnum, found_strategy)) = panic_runtime {
-        let desired_strategy = sess.opts.cg.panic.clone();
+        let desired_strategy = sess.panic_strategy();
 
         // First up, validate that our selected panic runtime is indeed exactly
         // our same strategy.

src/librustc/middle/weak_lang_items.rs

@@ -10,10 +10,11 @@
 
 //! Validity checking for weak lang items
 
-use session::config::{self, PanicStrategy};
+use session::config;
 use session::Session;
 use middle::lang_items;
 
+use rustc_back::PanicStrategy;
 use syntax::ast;
 use syntax::parse::token::InternedString;
 use syntax_pos::Span;
@@ -92,7 +93,7 @@ fn verify(sess: &Session, items: &lang_items::LanguageItems) {
     // symbols. Other panic runtimes ensure that the relevant symbols are
     // available to link things together, but they're never exercised.
     let mut whitelisted = HashSet::new();
-    if sess.opts.cg.panic != PanicStrategy::Unwind {
+    if sess.panic_strategy() != PanicStrategy::Unwind {
         whitelisted.insert(lang_items::EhPersonalityLangItem);
         whitelisted.insert(lang_items::EhUnwindResumeLangItem);
     }