Auto merge of #33487 - steveklabnik:rollup, r=steveklabnik

Rollup of 20 pull requests

- Successful merges: #33256, #33283, #33313, #33314, #33326, #33336, #33382, #33384, #33402, #33409, #33410, #33412, #33428, #33430, #33437, #33438, #33439, #33442, #33456, #33459
- Failed merges:

mk/ctags.mk

@@ -15,14 +15,21 @@
 
 .PHONY: TAGS.emacs TAGS.vi
 
-CTAGS_LOCATIONS=$(wildcard ${CFG_SRC_DIR}src/lib*)
+CTAGS_RUSTC_LOCATIONS=$(patsubst ${CFG_SRC_DIR}src/lib%test,, \
+				$(wildcard ${CFG_SRC_DIR}src/lib*)) ${CFG_SRC_DIR}src/libtest
 CTAGS_LOCATIONS=$(patsubst ${CFG_SRC_DIR}src/librust%,, \
                 $(patsubst ${CFG_SRC_DIR}src/lib%test,, \
 				$(wildcard ${CFG_SRC_DIR}src/lib*))) ${CFG_SRC_DIR}src/libtest
-CTAGS_OPTS=--options="${CFG_SRC_DIR}src/etc/ctags.rust" --languages=Rust --recurse ${CTAGS_LOCATIONS}
+CTAGS_OPTS=--options="${CFG_SRC_DIR}src/etc/ctags.rust" --languages=Rust --recurse
+
+TAGS.rustc.emacs:
+	ctags -e -f $@ ${CTAGS_OPTS} ${CTAGS_RUSTC_LOCATIONS}
 
 TAGS.emacs:
-	ctags -e -f $@ ${CTAGS_OPTS}
+	ctags -e -f $@ ${CTAGS_OPTS} ${CTAGS_LOCATIONS}
+
+TAGS.rustc.vi:
+	ctags -f $@ ${CTAGS_OPTS} ${CTAGS_RUSTC_LOCATIONS}
 
 TAGS.vi:
-	ctags -f $@ ${CTAGS_OPTS}
+	ctags -f $@ ${CTAGS_OPTS} ${CTAGS_LOCATIONS}

mk/platform.mk

@@ -169,7 +169,7 @@ ifdef CFG_CCACHE_BASEDIR
   export CCACHE_BASEDIR
 endif
 
-FIND_COMPILER = $(word 1,$(1:ccache=))
+FIND_COMPILER = $(strip $(1:ccache=))
 
 define CFG_MAKE_TOOLCHAIN
   # Prepend the tools with their prefix if cross compiling
@@ -187,7 +187,7 @@ define CFG_MAKE_TOOLCHAIN
     endif
   endif
 
-  CFG_COMPILE_C_$(1) = '$$(CC_$(1))' \
+  CFG_COMPILE_C_$(1) = '$$(call FIND_COMPILER,$$(CC_$(1)))' \
         $$(CFLAGS) \
         $$(CFG_GCCISH_CFLAGS) \
         $$(CFG_GCCISH_CFLAGS_$(1)) \
@@ -198,7 +198,7 @@ define CFG_MAKE_TOOLCHAIN
         $$(CFG_GCCISH_LINK_FLAGS_$(1)) \
         $$(CFG_GCCISH_DEF_FLAG_$(1))$$(3) $$(2) \
         $$(call CFG_INSTALL_NAME_$(1),$$(4))
-  CFG_COMPILE_CXX_$(1) = '$$(CXX_$(1))' \
+  CFG_COMPILE_CXX_$(1) = '$$(call FIND_COMPILER,$$(CXX_$(1)))' \
         $$(CXXFLAGS) \
         $$(CFG_GCCISH_CFLAGS) \
         $$(CFG_GCCISH_CXXFLAGS) \

mk/tests.mk

@@ -635,8 +635,8 @@ CTEST_COMMON_ARGS$(1)-T-$(2)-H-$(3) = \
         --host-rustcflags "$(RUSTC_FLAGS_$(3)) $$(CTEST_RUSTC_FLAGS) -L $$(RT_OUTPUT_DIR_$(3))" \
         --lldb-python-dir=$(CFG_LLDB_PYTHON_DIR) \
         --target-rustcflags "$(RUSTC_FLAGS_$(2)) $$(CTEST_RUSTC_FLAGS) -L $$(RT_OUTPUT_DIR_$(2))" \
-	--cc '$$(CC_$(2))' \
-	--cxx '$$(CXX_$(2))' \
+	--cc '$$(call FIND_COMPILER,$$(CC_$(2)))' \
+	--cxx '$$(call FIND_COMPILER,$$(CXX_$(2)))' \
 	--cflags "$$(CFG_GCCISH_CFLAGS_$(2))" \
 	--llvm-components "$$(LLVM_ALL_COMPONENTS_$(2))" \
 	--llvm-cxxflags "$$(LLVM_CXXFLAGS_$(2))" \

src/bootstrap/build/job.rs

@@ -54,7 +54,7 @@ pub unsafe fn setup() {
 
     // Indicate that when all handles to the job object are gone that all
     // process in the object should be killed. Note that this includes our
-    // entire process tree by default because we've added ourselves and and our
+    // entire process tree by default because we've added ourselves and our
     // children will reside in the job by default.
     let mut info = mem::zeroed::<JOBOBJECT_EXTENDED_LIMIT_INFORMATION>();
     info.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;

src/doc/reference.md

@@ -2063,33 +2063,41 @@ arbitrarily complex configurations through nesting.
 
 The following configurations must be defined by the implementation:
 
-* `debug_assertions` - Enabled by default when compiling without optimizations.
-  This can be used to enable extra debugging code in development but not in
-  production.  For example, it controls the behavior of the standard library's
-  `debug_assert!` macro.
-* `target_arch = "..."` - Target CPU architecture, such as `"x86"`, `"x86_64"`
-  `"mips"`, `"powerpc"`, `"powerpc64"`, `"arm"`, or `"aarch64"`.
-* `target_endian = "..."` - Endianness of the target CPU, either `"little"` or
-  `"big"`.
-* `target_env = ".."` - An option provided by the compiler by default
-  describing the runtime environment of the target platform. Some examples of
-  this are `musl` for builds targeting the MUSL libc implementation, `msvc` for
-  Windows builds targeting MSVC, and `gnu` frequently the rest of the time. This
-  option may also be blank on some platforms.
+* `target_arch = "..."` - Target CPU architecture, such as `"x86"`,
+  `"x86_64"` `"mips"`, `"powerpc"`, `"powerpc64"`, `"arm"`, or
+  `"aarch64"`. This value is closely related to the first element of
+  the platform target triple, though it is not identical.
+* `target_os = "..."` - Operating system of the target, examples
+  include `"windows"`, `"macos"`, `"ios"`, `"linux"`, `"android"`,
+  `"freebsd"`, `"dragonfly"`, `"bitrig"` , `"openbsd"` or
+  `"netbsd"`. This value is closely related to the second and third
+  element of the platform target triple, though it is not identical.
 * `target_family = "..."` - Operating system family of the target, e. g.
   `"unix"` or `"windows"`. The value of this configuration option is defined
   as a configuration itself, like `unix` or `windows`.
-* `target_os = "..."` - Operating system of the target, examples include
-  `"windows"`, `"macos"`, `"ios"`, `"linux"`, `"android"`, `"freebsd"`, `"dragonfly"`,
-  `"bitrig"` , `"openbsd"` or `"netbsd"`.
+* `unix` - See `target_family`.
+* `windows` - See `target_family`.
+* `target_env = ".."` - Further disambiguates the target platform with
+  information about the ABI/libc. Presently this value is either
+  `"gnu"`, `"msvc"`, `"musl"`, or the empty string. For historical
+  reasons this value has only been defined as non-empty when needed
+  for disambiguation. Thus on many GNU platforms this value will be
+  empty. This value is closely related to the fourth element of the
+  platform target triple, though it is not identical. For example,
+  embedded ABIs such as `gnueabihf` will simply define `target_env` as
+  `"gnu"`.
+* `target_endian = "..."` - Endianness of the target CPU, either `"little"` or
+  `"big"`.
 * `target_pointer_width = "..."` - Target pointer width in bits. This is set
   to `"32"` for targets with 32-bit pointers, and likewise set to `"64"` for
   64-bit pointers.
 * `target_vendor = "..."` - Vendor of the target, for example `apple`, `pc`, or
   simply `"unknown"`.
 * `test` - Enabled when compiling the test harness (using the `--test` flag).
-* `unix` - See `target_family`.
-* `windows` - See `target_family`.
+* `debug_assertions` - Enabled by default when compiling without optimizations.
+  This can be used to enable extra debugging code in development but not in
+  production.  For example, it controls the behavior of the standard library's
+  `debug_assert!` macro.
 
 You can also set another attribute based on a `cfg` variable with `cfg_attr`:
 

src/libcollections/slice.rs

@@ -419,8 +419,8 @@ impl<T> [T] {
     ///
     /// ```rust
     /// let v = &[1, 2, 3, 4, 5];
-    /// for win in v.chunks(2) {
-    ///     println!("{:?}", win);
+    /// for chunk in v.chunks(2) {
+    ///     println!("{:?}", chunk);
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/iter/iterator.rs

@@ -214,7 +214,7 @@ pub trait Iterator {
     /// Like most indexing operations, the count starts from zero, so `nth(0)`
     /// returns the first value, `nth(1)` the second, and so on.
     ///
-    /// `nth()` will return `None` if `n` is larger than the length of the
+    /// `nth()` will return `None` if `n` is greater than or equal to the length of the
     /// iterator.
     ///
     /// # Examples
@@ -237,7 +237,7 @@ pub trait Iterator {
     /// assert_eq!(iter.nth(1), None);
     /// ```
     ///
-    /// Returning `None` if there are less than `n` elements:
+    /// Returning `None` if there are less than `n + 1` elements:
     ///
     /// ```
     /// let a = [1, 2, 3];

src/libcore/num/mod.rs

@@ -37,6 +37,17 @@ use slice::SliceExt;
 /// `wrapping_add`, or through the `Wrapping<T>` type, which says that
 /// all standard arithmetic operations on the underlying value are
 /// intended to have wrapping semantics.
+///
+/// # Examples
+///
+/// ```
+/// use std::num::Wrapping;
+///
+/// let zero = Wrapping(0u32);
+/// let one = Wrapping(1u32);
+///
+/// assert_eq!(std::u32::MAX, (zero - one).0);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Default, Hash)]
 pub struct Wrapping<T>(#[stable(feature = "rust1", since = "1.0.0")] pub T);

src/librustc/dep_graph/thread.rs

@@ -176,6 +176,9 @@ pub fn main(swap_in: Receiver<Vec<DepMessage>>,
                 DepMessage::Query => query_out.send(edges.query()).unwrap(),
             }
         }
-        swap_out.send(messages).unwrap();
+        if let Err(_) = swap_out.send(messages) {
+            // the receiver must have been dropped already
+            break;
+        }
     }
 }

src/librustc/session/config.rs

@@ -1355,7 +1355,7 @@ pub mod nightly_options {
                     early_error(ErrorOutputType::default(), &msg);
                 }
                 OptionStability::UnstableButNotReally => {
-                    let msg = format!("the option `{}` is is unstable and should \
+                    let msg = format!("the option `{}` is unstable and should \
                                        only be used on the nightly compiler, but \
                                        it is currently accepted for backwards \
                                        compatibility; this will soon change, \

src/librustc/traits/project.rs

@@ -40,7 +40,7 @@ use std::rc::Rc;
 pub enum ProjectionMode {
     /// FIXME (#32205)
     /// At coherence-checking time, we're still constructing the
-    /// specialization graph, and thus we only project project
+    /// specialization graph, and thus we only project
     /// non-`default` associated types that are defined directly in
     /// the applicable impl. (This behavior should be improved over
     /// time, to allow for successful projections modulo cycles

src/librustc/ty/trait_def.rs

@@ -176,7 +176,7 @@ impl<'tcx> TraitDef<'tcx> {
     /// Records a trait-to-implementation mapping for a non-local impl.
     ///
     /// The `parent_impl` is the immediately-less-specialized impl, or the
-    /// trait's def ID if the impl is is not a specialization -- information that
+    /// trait's def ID if the impl is not a specialization -- information that
     /// should be pulled from the metadata.
     pub fn record_remote_impl(&self,
                               tcx: &TyCtxt<'tcx>,

src/librustc/ty/wf.rs

@@ -272,7 +272,7 @@ impl<'a,'tcx> WfPredicates<'a,'tcx> {
     /// into `self.out`.
     fn compute_projection(&mut self, data: ty::ProjectionTy<'tcx>) {
         // A projection is well-formed if (a) the trait ref itself is
-        // WF WF and (b) the trait-ref holds.  (It may also be
+        // WF and (b) the trait-ref holds.  (It may also be
         // normalizable and be WF that way.)
 
         self.compute_trait_ref(&data.trait_ref);

src/librustc_back/target/mod.rs

@@ -202,7 +202,7 @@ pub struct TargetOptions {
     pub post_link_args: Vec<String>,
 
     /// Default CPU to pass to LLVM. Corresponds to `llc -mcpu=$cpu`. Defaults
-    /// to "default".
+    /// to "generic".
     pub cpu: String,
     /// Default target features to pass to LLVM. These features will *always* be
     /// passed, and cannot be disabled even via `-C`. Corresponds to `llc