Auto merge of #45233 - kennytm:rollup, r=kennytm

Rollup of 9 pull requests

- Successful merges: #44989, #45005, #45049, #45105, #45121, #45166, #45172, #45190, #45231
- Failed merges: #45138

src/bootstrap/bin/rustdoc.rs

@@ -48,6 +48,14 @@ fn main() {
         cmd.arg("-Z").arg("force-unstable-if-unmarked");
     }
 
+    // Bootstrap's Cargo-command builder sets this variable to the current Rust version; let's pick
+    // it up so we can make rustdoc print this into the docs
+    if let Some(version) = env::var_os("RUSTDOC_CRATE_VERSION") {
+        // This "unstable-options" can be removed when `--crate-version` is stabilized
+        cmd.arg("-Z").arg("unstable-options")
+           .arg("--crate-version").arg(version);
+    }
+
     std::process::exit(match cmd.status() {
         Ok(s) => s.code().unwrap_or(1),
         Err(e) => panic!("\n\nfailed to run {:?}: {}\n\n", cmd, e),

src/bootstrap/bootstrap.py

@@ -302,6 +302,7 @@ def default_build_triple():
 
     return "{}-{}".format(cputype, ostype)
 
+
 class RustBuild(object):
     """Provide all the methods required to build Rust"""
     def __init__(self):

src/bootstrap/builder.rs

@@ -418,7 +418,8 @@ impl<'a> Builder<'a> {
             .env("RUSTC_SYSROOT", self.sysroot(compiler))
             .env("RUSTC_LIBDIR", self.sysroot_libdir(compiler, self.build.build))
             .env("CFG_RELEASE_CHANNEL", &self.build.config.channel)
-            .env("RUSTDOC_REAL", self.rustdoc(host));
+            .env("RUSTDOC_REAL", self.rustdoc(host))
+            .env("RUSTDOC_CRATE_VERSION", self.build.rust_version());
         cmd
     }
 
@@ -574,6 +575,9 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTC_SAVE_ANALYSIS", "api".to_string());
         }
 
+        // For `cargo doc` invocations, make rustdoc print the Rust version into the docs
+        cargo.env("RUSTDOC_CRATE_VERSION", self.build.rust_version());
+
         // Environment variables *required* throughout the build
         //
         // FIXME: should update code to not require this env var

src/bootstrap/configure.py

@@ -19,21 +19,26 @@
 sys.path.append(os.path.join(rust_dir, "src", "bootstrap"))
 import bootstrap
 
+
 class Option:
     def __init__(self, name, rustbuild, desc, value):
         self.name = name
         self.rustbuild = rustbuild
         self.desc = desc
         self.value = value
 
+
 options = []
 
+
 def o(*args):
     options.append(Option(*args, value=False))
 
+
 def v(*args):
     options.append(Option(*args, value=True))
 
+
 o("debug", "rust.debug", "debug mode; disables optimization unless `--enable-optimize` given")
 o("docs", "build.docs", "build standard library documentation")
 o("compiler-docs", "build.compiler-docs", "build compiler documentation")
@@ -136,13 +141,16 @@ def v(*args):
 
 v("set", None, "set arbitrary key/value pairs in TOML configuration")
 
+
 def p(msg):
     print("configure: " + msg)
 
+
 def err(msg):
     print("configure: error: " + msg)
     sys.exit(1)
 
+
 if '--help' in sys.argv or '-h' in sys.argv:
     print('Usage: ./configure [options]')
     print('')
@@ -208,7 +216,7 @@ def err(msg):
                 continue
 
         found = True
-        if not option.name in known_args:
+        if option.name not in known_args:
             known_args[option.name] = []
         known_args[option.name].append((option, value))
         break
@@ -227,27 +235,30 @@ def err(msg):
 # TOML we're going to write out
 config = {}
 
+
 def build():
     if 'build' in known_args:
         return known_args['build'][0][1]
     return bootstrap.default_build_triple()
 
+
 def set(key, value):
-      s = "{:20} := {}".format(key, value)
-      if len(s) < 70:
-          p(s)
-      else:
-          p(s[:70] + " ...")
-
-      arr = config
-      parts = key.split('.')
-      for i, part in enumerate(parts):
-          if i == len(parts) - 1:
-              arr[part] = value
-          else:
-              if not part in arr:
-                  arr[part] = {}
-              arr = arr[part]
+    s = "{:20} := {}".format(key, value)
+    if len(s) < 70:
+        p(s)
+    else:
+        p(s[:70] + " ...")
+
+    arr = config
+    parts = key.split('.')
+    for i, part in enumerate(parts):
+        if i == len(parts) - 1:
+            arr[part] = value
+        else:
+            if part not in arr:
+                arr[part] = {}
+            arr = arr[part]
+
 
 for key in known_args:
     # The `set` option is special and can be passed a bunch of times
@@ -345,6 +356,7 @@ def set(key, value):
     targets[target] = sections['target'][:]
     targets[target][0] = targets[target][0].replace("x86_64-unknown-linux-gnu", target)
 
+
 # Here we walk through the constructed configuration we have from the parsed
 # command line arguments. We then apply each piece of configuration by
 # basically just doing a `sed` to change the various configuration line to what
@@ -362,6 +374,7 @@ def to_toml(value):
     else:
         raise RuntimeError('no toml')
 
+
 def configure_section(lines, config):
     for key in config:
         value = config[key]
@@ -375,9 +388,10 @@ def configure_section(lines, config):
         if not found:
             raise RuntimeError("failed to find config line for {}".format(key))
 
+
 for section_key in config:
     section_config = config[section_key]
-    if not section_key in sections:
+    if section_key not in sections:
         raise RuntimeError("config key {} not in sections".format(section_key))
 
     if section_key == 'target':

src/doc/unstable-book/src/language-features/optin-builtin-traits.md

@@ -0,0 +1,47 @@
+# `optin_builtin_traits`
+
+The tracking issue for this feature is [#13231] 
+
+[#13231]: https://github.com/rust-lang/rust/issues/13231
+
+----
+
+The `optin_builtin_traits` feature gate allows you to define auto traits.
+
+Auto traits, like [`Send`] or [`Sync`] in the standard library, are marker traits
+that are automatically implemented for every type, unless the type, or a type it contains, 
+has explictly opted out via a negative impl. 
+
+[`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html
+[`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html
+
+```rust,ignore
+impl !Type for Trait
+```
+
+Example:
+
+```rust
+#![feature(optin_builtin_traits)]
+
+trait Valid {}
+
+impl Valid for .. {}
+
+struct True;
+struct False;
+
+impl !Valid for False {}
+
+struct MaybeValid<T>(T);
+
+fn must_be_valid<T: Valid>(_t: T) { }
+
+fn main() {
+    // works
+    must_be_valid( MaybeValid(True) );
+
+    // compiler error - trait bound not satisfied
+    // must_be_valid( MaybeValid(False) );
+}
+```

src/doc/unstable-book/src/language-features/unboxed-closures.md

@@ -0,0 +1,25 @@
+# `unboxed_closures`
+
+The tracking issue for this feature is [#29625]
+
+See Also: [`fn_traits`](library-features/fn-traits.html)
+
+[#29625]: https://github.com/rust-lang/rust/issues/29625
+
+----
+
+The `unboxed_closures` feature allows you to write functions using the `"rust-call"` ABI,
+required for implmenting the [`Fn*`] family of traits. `"rust-call"` functions must have 
+exactly one (non self) argument, a tuple representing the argument list.
+
+[`Fn*`]: https://doc.rust-lang.org/std/ops/trait.Fn.html
+
+```rust
+#![feature(unboxed_closures)]
+
+extern "rust-call" fn add_args(args: (u32, u32)) -> u32 {
+    args.0 + args.1
+}
+
+fn main() {}
+```

src/doc/unstable-book/src/library-features/fn-traits.md

@@ -0,0 +1,35 @@
+# `fn_traits`
+
+The tracking issue for this feature is [#29625]
+
+See Also: [`unboxed_closures`](language-features/unboxed-closures.html)
+
+[#29625]: https://github.com/rust-lang/rust/issues/29625
+
+----
+
+The `fn_traits` feature allows for implementation of the [`Fn*`] traits
+for creating custom closure-like types.
+
+[`Fn*`]: https://doc.rust-lang.org/std/ops/trait.Fn.html
+
+```rust
+#![feature(unboxed_closures)]
+#![feature(fn_traits)]
+
+struct Adder {
+    a: u32
+}
+
+impl FnOnce<(u32, )> for Adder {
+    type Output = u32;
+    extern "rust-call" fn call_once(self, b: (u32, )) -> Self::Output {
+        self.a + b.0
+    }
+}
+
+fn main() {
+    let adder = Adder { a: 3 };
+    assert_eq!(adder(2), 5);
+}
+```

src/libcore/str/mod.rs

@@ -1405,16 +1405,6 @@ impl<'a> DoubleEndedIterator for LinesAny<'a> {
 #[allow(deprecated)]
 impl<'a> FusedIterator for LinesAny<'a> {}
 
-/*
-Section: Comparing strings
-*/
-
-/// Bytewise slice equality
-#[inline]
-fn eq_slice(a: &str, b: &str) -> bool {
-    a.as_bytes() == b.as_bytes()
-}
-
 /*
 Section: UTF-8 validation
 */
@@ -1590,7 +1580,6 @@ mod traits {
     use cmp::Ordering;
     use ops;
     use slice::{self, SliceIndex};
-    use str::eq_slice;
 
     /// Implements ordering of strings.
     ///
@@ -1611,7 +1600,7 @@ mod traits {
     impl PartialEq for str {
         #[inline]
         fn eq(&self, other: &str) -> bool {
-            eq_slice(self, other)
+            self.as_bytes() == other.as_bytes()
         }
         #[inline]
         fn ne(&self, other: &str) -> bool { !(*self).eq(other) }

src/librustc/hir/itemlikevisit.rs

@@ -41,7 +41,7 @@ use super::intravisit::Visitor;
 ///    - Example: Lifetime resolution, which wants to bring lifetimes declared on the
 ///      impl into scope while visiting the impl-items, and then back out again.
 ///    - How: Implement `intravisit::Visitor` and override the
-///      `visit_nested_map()` methods to return
+///      `nested_visit_map()` methods to return
 ///      `NestedVisitorMap::All`. Walk your crate with
 ///      `intravisit::walk_crate()` invoked on `tcx.hir.krate()`.
 ///    - Pro: Visitor methods for any kind of HIR node, not just item-like things.