Auto merge of #48531 - kennytm:rollup, r=kennytm

Rollup of 17 pull requests

- Successful merges: #47964, #47970, #48076, #48115, #48166, #48281, #48297, #48302, #48362, #48369, #48489, #48491, #48494, #48517, #48529, #48235, #48330
- Failed merges:

src/bootstrap/bin/rustc.rs

@@ -61,6 +61,11 @@ fn main() {
         args.remove(n);
     }
 
+    if let Some(s) = env::var_os("RUSTC_ERROR_FORMAT") {
+        args.push("--error-format".into());
+        args.push(s);
+    }
+
     // Detect whether or not we're a build script depending on whether --target
     // is passed (a bit janky...)
     let target = args.windows(2)

src/bootstrap/bootstrap.py

@@ -294,7 +294,7 @@ def default_build_triple():
             raise ValueError('unknown byteorder: {}'.format(sys.byteorder))
         # only the n64 ABI is supported, indicate it
         ostype += 'abi64'
-    elif cputype == 'sparcv9' or cputype == 'sparc64':
+    elif cputype == 'sparc' or cputype == 'sparcv9' or cputype == 'sparc64':
         pass
     else:
         err = "unknown cpu type: {}".format(cputype)

src/bootstrap/builder.rs

@@ -444,10 +444,11 @@ impl<'a> Builder<'a> {
 
             fn run(self, builder: &Builder) -> Interned<PathBuf> {
                 let compiler = self.compiler;
-                let lib = if compiler.stage >= 1 && builder.build.config.libdir.is_some() {
-                    builder.build.config.libdir.clone().unwrap()
+                let config = &builder.build.config;
+                let lib = if compiler.stage >= 1 && config.libdir_relative().is_some() {
+                    builder.build.config.libdir_relative().unwrap()
                 } else {
-                    PathBuf::from("lib")
+                    Path::new("lib")
                 };
                 let sysroot = builder.sysroot(self.compiler).join(lib)
                     .join("rustlib").join(self.target).join("lib");
@@ -598,6 +599,9 @@ impl<'a> Builder<'a> {
         if let Some(target_linker) = self.build.linker(target) {
             cargo.env("RUSTC_TARGET_LINKER", target_linker);
         }
+        if let Some(ref error_format) = self.config.rustc_error_format {
+            cargo.env("RUSTC_ERROR_FORMAT", error_format);
+        }
         if cmd != "build" && cmd != "check" {
             cargo.env("RUSTDOC_LIBDIR", self.rustc_libdir(self.compiler(2, self.build.build)));
         }

src/bootstrap/compile.rs

@@ -516,8 +516,7 @@ fn rustc_cargo_env(build: &Build, cargo: &mut Command) {
          .env("CFG_VERSION", build.rust_version())
          .env("CFG_PREFIX", build.config.prefix.clone().unwrap_or_default());
 
-    let libdir_relative =
-        build.config.libdir.clone().unwrap_or(PathBuf::from("lib"));
+    let libdir_relative = build.config.libdir_relative().unwrap_or(Path::new("lib"));
     cargo.env("CFG_LIBDIR_RELATIVE", libdir_relative);
 
     // If we're not building a compiler with debugging information then remove

src/bootstrap/config.rs

@@ -17,7 +17,7 @@ use std::collections::{HashMap, HashSet};
 use std::env;
 use std::fs::File;
 use std::io::prelude::*;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process;
 use std::cmp;
 
@@ -57,6 +57,7 @@ pub struct Config {
     pub profiler: bool,
     pub ignore_git: bool,
     pub exclude: Vec<PathBuf>,
+    pub rustc_error_format: Option<String>,
 
     pub run_host_only: bool,
 
@@ -330,6 +331,7 @@ impl Config {
         config.test_miri = false;
         config.rust_codegen_backends = vec![INTERNER.intern_str("llvm")];
 
+        config.rustc_error_format = flags.rustc_error_format;
         config.on_fail = flags.on_fail;
         config.stage = flags.stage;
         config.src = flags.src;
@@ -564,6 +566,17 @@ impl Config {
         config
     }
 
+    /// Try to find the relative path of `libdir`.
+    pub fn libdir_relative(&self) -> Option<&Path> {
+        let libdir = self.libdir.as_ref()?;
+        if libdir.is_relative() {
+            Some(libdir)
+        } else {
+            // Try to make it relative to the prefix.
+            libdir.strip_prefix(self.prefix.as_ref()?).ok()
+        }
+    }
+
     pub fn verbose(&self) -> bool {
         self.verbose > 0
     }

src/bootstrap/flags.rs

@@ -43,6 +43,7 @@ pub struct Flags {
     pub cmd: Subcommand,
     pub incremental: bool,
     pub exclude: Vec<PathBuf>,
+    pub rustc_error_format: Option<String>,
 }
 
 pub enum Subcommand {
@@ -118,6 +119,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`");
         opts.optopt("", "src", "path to the root of the rust checkout", "DIR");
         opts.optopt("j", "jobs", "number of jobs to run in parallel", "JOBS");
         opts.optflag("h", "help", "print this help message");
+        opts.optflag("", "error-format", "rustc error format");
 
         // fn usage()
         let usage = |exit_code: i32, opts: &Options, subcommand_help: &str, extra_help: &str| -> ! {
@@ -370,6 +372,7 @@ Arguments:
             verbose: matches.opt_count("verbose"),
             stage,
             on_fail: matches.opt_str("on-fail"),
+            rustc_error_format: matches.opt_str("error-format"),
             keep_stage: matches.opt_str("keep-stage").map(|j| j.parse().unwrap()),
             build: matches.opt_str("build").map(|s| INTERNER.intern_string(s)),
             host: split(matches.opt_strs("host"))

src/bootstrap/native.rs

@@ -480,16 +480,19 @@ impl Step for Openssl {
             "mips64el-unknown-linux-gnuabi64" => "linux64-mips64",
             "mipsel-unknown-linux-gnu" => "linux-mips32",
             "powerpc-unknown-linux-gnu" => "linux-ppc",
+            "powerpc-unknown-netbsd" => "BSD-generic32",
             "powerpc64-unknown-linux-gnu" => "linux-ppc64",
             "powerpc64le-unknown-linux-gnu" => "linux-ppc64le",
             "s390x-unknown-linux-gnu" => "linux64-s390x",
+            "sparc-unknown-linux-gnu" => "linux-sparcv9",
             "sparc64-unknown-linux-gnu" => "linux64-sparcv9",
             "sparc64-unknown-netbsd" => "BSD-sparc64",
             "x86_64-apple-darwin" => "darwin64-x86_64-cc",
             "x86_64-linux-android" => "linux-x86_64",
             "x86_64-unknown-freebsd" => "BSD-x86_64",
             "x86_64-unknown-dragonfly" => "BSD-x86_64",
             "x86_64-unknown-linux-gnu" => "linux-x86_64",
+            "x86_64-unknown-linux-gnux32" => "linux-x32",
             "x86_64-unknown-linux-musl" => "linux-x86_64",
             "x86_64-unknown-netbsd" => "BSD-x86_64",
             _ => panic!("don't know how to configure OpenSSL for {}", target),

src/liballoc/btree/map.rs

@@ -2114,7 +2114,6 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(entry_and_modify)]
     /// use std::collections::BTreeMap;
     ///
     /// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
@@ -2129,7 +2128,7 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
     ///    .or_insert(42);
     /// assert_eq!(map["poneyland"], 43);
     /// ```
-    #[unstable(feature = "entry_and_modify", issue = "44733")]
+    #[stable(feature = "entry_and_modify", since = "1.26.0")]
     pub fn and_modify<F>(self, mut f: F) -> Self
         where F: FnMut(&mut V)
     {

src/libcore/iter/iterator.rs

@@ -12,7 +12,8 @@ use cmp::Ordering;
 use ops::Try;
 
 use super::{AlwaysOk, LoopState};
-use super::{Chain, Cycle, Cloned, Enumerate, Filter, FilterMap, FlatMap, Fuse};
+use super::{Chain, Cycle, Cloned, Enumerate, Filter, FilterMap, Fuse};
+use super::{Flatten, FlatMap, flatten_compat};
 use super::{Inspect, Map, Peekable, Scan, Skip, SkipWhile, StepBy, Take, TakeWhile, Rev};
 use super::{Zip, Sum, Product};
 use super::{ChainState, FromIterator, ZipImpl};
@@ -997,11 +998,15 @@ pub trait Iterator {
     /// an extra layer of indirection. `flat_map()` will remove this extra layer
     /// on its own.
     ///
+    /// You can think of [`flat_map(f)`][flat_map] as the semantic equivalent
+    /// of [`map`]ping, and then [`flatten`]ing as in `map(f).flatten()`.
+    ///
     /// Another way of thinking about `flat_map()`: [`map`]'s closure returns
     /// one item for each element, and `flat_map()`'s closure returns an
     /// iterator for each element.
     ///
     /// [`map`]: #method.map
+    /// [`flatten`]: #method.flatten
     ///
     /// # Examples
     ///
@@ -1021,7 +1026,79 @@ pub trait Iterator {
     fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
         where Self: Sized, U: IntoIterator, F: FnMut(Self::Item) -> U,
     {
-        FlatMap{iter: self, f: f, frontiter: None, backiter: None }
+        FlatMap { inner: flatten_compat(self.map(f)) }
+    }
+
+    /// Creates an iterator that flattens nested structure.
+    ///
+    /// This is useful when you have an iterator of iterators or an iterator of
+    /// things that can be turned into iterators and you want to remove one
+    /// level of indirection.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(iterator_flatten)]
+    ///
+    /// let data = vec![vec![1, 2, 3, 4], vec![5, 6]];
+    /// let flattened = data.into_iter().flatten().collect::<Vec<u8>>();
+    /// assert_eq!(flattened, &[1, 2, 3, 4, 5, 6]);
+    /// ```
+    ///
+    /// Mapping and then flattening:
+    ///
+    /// ```
+    /// #![feature(iterator_flatten)]
+    ///
+    /// let words = ["alpha", "beta", "gamma"];
+    ///
+    /// // chars() returns an iterator
+    /// let merged: String = words.iter()
+    ///                           .map(|s| s.chars())
+    ///                           .flatten()
+    ///                           .collect();
+    /// assert_eq!(merged, "alphabetagamma");
+    /// ```
+    ///
+    /// You can also rewrite this in terms of [`flat_map()`] which is preferable
+    /// in this case since that conveys intent clearer:
+    ///
+    /// ```
+    /// let words = ["alpha", "beta", "gamma"];
+    ///
+    /// // chars() returns an iterator
+    /// let merged: String = words.iter()
+    ///                           .flat_map(|s| s.chars())
+    ///                           .collect();
+    /// assert_eq!(merged, "alphabetagamma");
+    /// ```
+    ///
+    /// Flattening once only removes one level of nesting:
+    ///
+    /// ```
+    /// #![feature(iterator_flatten)]
+    ///
+    /// let d3 = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]];
+    ///
+    /// let d2 = d3.iter().flatten().collect::<Vec<_>>();
+    /// assert_eq!(d2, [&[1, 2], &[3, 4], &[5, 6], &[7, 8]]);
+    ///
+    /// let d1 = d3.iter().flatten().flatten().collect::<Vec<_>>();
+    /// assert_eq!(d1, [&1, &2, &3, &4, &5, &6, &7, &8]);
+    /// ```
+    ///
+    /// Here we see that `flatten()` does not perform a "deep" flatten.
+    /// Instead, only one level of nesting is removed. That is, if you
+    /// `flatten()` a three-dimensional array the result will be
+    /// two-dimensional and not one-dimensional. To get a one-dimensional
+    /// structure, you have to `flatten()` again.
+    #[inline]
+    #[unstable(feature = "iterator_flatten", issue = "48213")]
+    fn flatten(self) -> Flatten<Self>
+    where Self: Sized, Self::Item: IntoIterator {
+        Flatten { inner: flatten_compat(self) }
     }
 
     /// Creates an iterator which ends after the first [`None`].