Auto merge of #53433 - kennytm:rollup, r=kennytm

Rollup of 10 pull requests

Successful merges:

 - #52946 (Documented impl From on line 367 of libserialize/json.rs)
 - #53234 (Remove Travis shutdown debug scripts, and remove CI-specific DNS settings)
 - #53313 (Two small improvements)
 - #53360 (Addressed #51602)
 - #53364 (Warn if the user tries to use GATs)
 - #53373 (Tweak unclosed delimiter parser error)
 - #53377 (std: Use target_pointer_width for BACKTRACE_ELF_SIZE)
 - #53395 (Use #[non_exhaustive] on internal enums)
 - #53399 (Tidy: ignore non-Markdown files when linting for the Unstable Book)
 - #53412 (syntax_ext: remove leftover span_err_if_not_stage0 macro.)

.travis.yml

@@ -218,10 +218,6 @@ before_install:
       echo '{"ipv6":true,"fixed-cidr-v6":"fd9a:8454:6789:13f7::/64"}' | sudo tee /etc/docker/daemon.json;
       sudo service docker restart;
     fi
-  - date
-  - sudo atq || true
-  - sudo grep -rE 'shutdown|poweroff|halt' /var/spool/cron || true
-  - sudo grep -E 'google-clock-skew|ntpd|startup-script' /var/log/syslog || true
 
 install:
   - case "$TRAVIS_OS_NAME" in
@@ -278,8 +274,6 @@ after_success:
       du . | sort -nr | head -n100
 
 after_failure:
-  # Requested by travis to debug "shutting down NOW" errors
-  - sudo tail -n 500 /var/log/syslog
   - >
       echo "#### Build failed; Disk usage after running script:";
       df -h;

src/Cargo.lock

@@ -100,7 +100,7 @@ name = "backtrace"
 version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace-sys 0.1.23 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace-sys 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "cfg-if 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-demangle 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -109,7 +109,7 @@ dependencies = [
 
 [[package]]
 name = "backtrace-sys"
-version = "0.1.23"
+version = "0.1.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cc 1.0.18 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3125,7 +3125,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum assert_cli 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "98589b0e465a6c510d95fceebd365bb79bedece7f6e18a480897f2015f85ec51"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "89a47830402e9981c5c41223151efcced65a0510c13097c769cede7efb34782a"
-"checksum backtrace-sys 0.1.23 (registry+https://github.com/rust-lang/crates.io-index)" = "bff67d0c06556c0b8e6b5f090f0eac52d950d9dfd1d35ba04e4ca3543eaf6a7e"
+"checksum backtrace-sys 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)" = "c66d56ac8dabd07f6aacdaf633f4b8262f5b3601a810a0dcddffd5c22c69daa0"
 "checksum bitflags 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4efd02e230a02e18f92fc2735f44597385ed02ad8f831e7c1c1156ee5e1ab3a5"
 "checksum bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d0c54bb8f454c567f21197eefcdbf5679d0bd99f2ddbe52e84c77061952e6789"
 "checksum bufstream 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f2f382711e76b9de6c744cc00d0497baba02fb00a787f088c879f01d09468e32"

src/ci/docker/run.sh

@@ -119,10 +119,6 @@ fi
 # goes ahead and sets it for all builders.
 args="$args --privileged"
 
-if [ "$CI" != "" ]; then
-    args="$args --dns 8.8.8.8 --dns 8.8.4.4 --dns 1.1.1.1 --dns 1.0.0.1"
-fi
-
 exec docker \
   run \
   --volume "$root_dir:/checkout:ro" \

src/libcore/lib.rs

@@ -120,6 +120,7 @@
 #![feature(const_slice_len)]
 #![feature(const_str_as_bytes)]
 #![feature(const_str_len)]
+#![feature(non_exhaustive)]
 
 #[prelude_import]
 #[allow(unused)]

src/libcore/sync/atomic.rs

@@ -185,6 +185,7 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 /// [nomicon]: ../../../nomicon/atomics.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum Ordering {
     /// No ordering constraints, only atomic operations.
     ///
@@ -256,10 +257,6 @@ pub enum Ordering {
     /// [`AcqRel`]: https://llvm.org/docs/Atomics.html#acquirerelease
     #[stable(feature = "rust1", since = "1.0.0")]
     SeqCst,
-    // Prevent exhaustive matching to allow for future extension
-    #[doc(hidden)]
-    #[unstable(feature = "future_atomic_orderings", issue = "0")]
-    __Nonexhaustive,
 }
 
 /// An [`AtomicBool`] initialized to `false`.
@@ -1954,7 +1951,6 @@ fn strongest_failure_ordering(order: Ordering) -> Ordering {
         SeqCst => SeqCst,
         Acquire => Acquire,
         AcqRel => Acquire,
-        __Nonexhaustive => __Nonexhaustive,
     }
 }
 
@@ -1966,7 +1962,6 @@ unsafe fn atomic_store<T>(dst: *mut T, val: T, order: Ordering) {
         SeqCst => intrinsics::atomic_store(dst, val),
         Acquire => panic!("there is no such thing as an acquire store"),
         AcqRel => panic!("there is no such thing as an acquire/release store"),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -1978,7 +1973,6 @@ unsafe fn atomic_load<T>(dst: *const T, order: Ordering) -> T {
         SeqCst => intrinsics::atomic_load(dst),
         Release => panic!("there is no such thing as a release load"),
         AcqRel => panic!("there is no such thing as an acquire/release load"),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -1991,7 +1985,6 @@ unsafe fn atomic_swap<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xchg_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xchg_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xchg(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2004,7 +1997,6 @@ unsafe fn atomic_add<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xadd_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xadd_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xadd(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2017,7 +2009,6 @@ unsafe fn atomic_sub<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xsub_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xsub_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xsub(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2039,8 +2030,6 @@ unsafe fn atomic_compare_exchange<T>(dst: *mut T,
         (AcqRel, Relaxed) => intrinsics::atomic_cxchg_acqrel_failrelaxed(dst, old, new),
         (SeqCst, Relaxed) => intrinsics::atomic_cxchg_failrelaxed(dst, old, new),
         (SeqCst, Acquire) => intrinsics::atomic_cxchg_failacq(dst, old, new),
-        (__Nonexhaustive, _) => panic!("invalid memory ordering"),
-        (_, __Nonexhaustive) => panic!("invalid memory ordering"),
         (_, AcqRel) => panic!("there is no such thing as an acquire/release failure ordering"),
         (_, Release) => panic!("there is no such thing as a release failure ordering"),
         _ => panic!("a failure ordering can't be stronger than a success ordering"),
@@ -2065,8 +2054,6 @@ unsafe fn atomic_compare_exchange_weak<T>(dst: *mut T,
         (AcqRel, Relaxed) => intrinsics::atomic_cxchgweak_acqrel_failrelaxed(dst, old, new),
         (SeqCst, Relaxed) => intrinsics::atomic_cxchgweak_failrelaxed(dst, old, new),
         (SeqCst, Acquire) => intrinsics::atomic_cxchgweak_failacq(dst, old, new),
-        (__Nonexhaustive, _) => panic!("invalid memory ordering"),
-        (_, __Nonexhaustive) => panic!("invalid memory ordering"),
         (_, AcqRel) => panic!("there is no such thing as an acquire/release failure ordering"),
         (_, Release) => panic!("there is no such thing as a release failure ordering"),
         _ => panic!("a failure ordering can't be stronger than a success ordering"),
@@ -2082,7 +2069,6 @@ unsafe fn atomic_and<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_and_acqrel(dst, val),
         Relaxed => intrinsics::atomic_and_relaxed(dst, val),
         SeqCst => intrinsics::atomic_and(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2094,7 +2080,6 @@ unsafe fn atomic_nand<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_nand_acqrel(dst, val),
         Relaxed => intrinsics::atomic_nand_relaxed(dst, val),
         SeqCst => intrinsics::atomic_nand(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2106,7 +2091,6 @@ unsafe fn atomic_or<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_or_acqrel(dst, val),
         Relaxed => intrinsics::atomic_or_relaxed(dst, val),
         SeqCst => intrinsics::atomic_or(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2118,7 +2102,6 @@ unsafe fn atomic_xor<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xor_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xor_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xor(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2131,7 +2114,6 @@ unsafe fn atomic_max<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_max_acqrel(dst, val),
         Relaxed => intrinsics::atomic_max_relaxed(dst, val),
         SeqCst => intrinsics::atomic_max(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2144,7 +2126,6 @@ unsafe fn atomic_min<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_min_acqrel(dst, val),
         Relaxed => intrinsics::atomic_min_relaxed(dst, val),
         SeqCst => intrinsics::atomic_min(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2157,7 +2138,6 @@ unsafe fn atomic_umax<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_umax_acqrel(dst, val),
         Relaxed => intrinsics::atomic_umax_relaxed(dst, val),
         SeqCst => intrinsics::atomic_umax(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2170,7 +2150,6 @@ unsafe fn atomic_umin<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_umin_acqrel(dst, val),
         Relaxed => intrinsics::atomic_umin_relaxed(dst, val),
         SeqCst => intrinsics::atomic_umin(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2260,7 +2239,6 @@ pub fn fence(order: Ordering) {
             AcqRel => intrinsics::atomic_fence_acqrel(),
             SeqCst => intrinsics::atomic_fence(),
             Relaxed => panic!("there is no such thing as a relaxed fence"),
-            __Nonexhaustive => panic!("invalid memory ordering"),
         }
     }
 }
@@ -2350,7 +2328,6 @@ pub fn compiler_fence(order: Ordering) {
             AcqRel => intrinsics::atomic_singlethreadfence_acqrel(),
             SeqCst => intrinsics::atomic_singlethreadfence(),
             Relaxed => panic!("there is no such thing as a relaxed compiler fence"),
-            __Nonexhaustive => panic!("invalid memory ordering"),
         }
     }
 }

src/libproc_macro/diagnostic.rs

@@ -16,6 +16,7 @@ use syntax_pos::MultiSpan;
 /// An enum representing a diagnostic level.
 #[unstable(feature = "proc_macro_diagnostic", issue = "38356")]
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum Level {
     /// An error.
     Error,
@@ -25,8 +26,6 @@ pub enum Level {
     Note,
     /// A help message.
     Help,
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// A structure representing a diagnostic message and associated children

src/libproc_macro/lib.rs

@@ -36,6 +36,7 @@
 #![feature(staged_api)]
 #![feature(lang_items)]
 #![feature(optin_builtin_traits)]
+#![feature(non_exhaustive)]
 
 #![recursion_limit="256"]
 

src/libproc_macro/rustc.rs

@@ -278,7 +278,6 @@ impl Level {
             Level::Warning => errors::Level::Warning,
             Level::Note => errors::Level::Note,
             Level::Help => errors::Level::Help,
-            Level::__Nonexhaustive => unreachable!("Level::__Nonexhaustive"),
         }
     }
 }

src/librustc_apfloat/ieee.rs

@@ -2306,24 +2306,14 @@ mod sig {
 
     /// One, not zero, based LSB. That is, returns 0 for a zeroed significand.
     pub(super) fn olsb(limbs: &[Limb]) -> usize {
-        for (i, &limb) in limbs.iter().enumerate() {
-            if limb != 0 {
-                return i * LIMB_BITS + limb.trailing_zeros() as usize + 1;
-            }
-        }
-
-        0
+        limbs.iter().enumerate().find(|(_, &limb)| limb != 0).map_or(0,
+            |(i, limb)| i * LIMB_BITS + limb.trailing_zeros() as usize + 1)
     }
 
     /// One, not zero, based MSB. That is, returns 0 for a zeroed significand.
     pub(super) fn omsb(limbs: &[Limb]) -> usize {
-        for (i, &limb) in limbs.iter().enumerate().rev() {
-            if limb != 0 {
-                return (i + 1) * LIMB_BITS - limb.leading_zeros() as usize;
-            }
-        }
-
-        0
+        limbs.iter().enumerate().rfind(|(_, &limb)| limb != 0).map_or(0,
+            |(i, limb)| (i + 1) * LIMB_BITS - limb.leading_zeros() as usize)
     }
 
     /// Comparison (unsigned) of two significands.

src/libserialize/json.rs

@@ -365,6 +365,9 @@ impl std::error::Error for EncoderError {
 }
 
 impl From<fmt::Error> for EncoderError {
+    /// Converts a [`fmt::Error`] into `EncoderError`
+    ///
+    /// This conversion does not allocate memory.
     fn from(err: fmt::Error) -> EncoderError { EncoderError::FmtError(err) }
 }
 
@@ -1387,10 +1390,9 @@ impl Stack {
 
     // Used by Parser to test whether the top-most element is an index.
     fn last_is_index(&self) -> bool {
-        if let Some(InternalIndex(_)) = self.stack.last() {
-            true
-        } else {
-            false
+        match self.stack.last() {
+            Some(InternalIndex(_)) => true,
+            _ => false,
         }
     }
 

src/libstd/build.rs

@@ -104,7 +104,8 @@ fn build_libbacktrace(target: &str) -> Result<(), ()> {
     } else {
         build.file("../libbacktrace/elf.c");
 
-        if target.contains("64") {
+        let pointer_width = env::var("CARGO_CFG_TARGET_POINTER_WIDTH").unwrap();
+        if pointer_width == "64" {
             build.define("BACKTRACE_ELF_SIZE", "64");
         } else {
             build.define("BACKTRACE_ELF_SIZE", "32");

src/libstd/io/error.rs

@@ -97,6 +97,7 @@ struct Custom {
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated)]
+#[non_exhaustive]
 pub enum ErrorKind {
     /// An entity was not found, often a file.
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -180,15 +181,6 @@ pub enum ErrorKind {
     /// read.
     #[stable(feature = "read_exact", since = "1.6.0")]
     UnexpectedEof,
-
-    /// A marker variant that tells the compiler that users of this enum cannot
-    /// match it exhaustively.
-    #[unstable(feature = "io_error_internals",
-               reason = "better expressed through extensible enums that this \
-                         enum cannot be exhaustively matched against",
-               issue = "0")]
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 impl ErrorKind {
@@ -212,7 +204,6 @@ impl ErrorKind {
             ErrorKind::Interrupted => "operation interrupted",
             ErrorKind::Other => "other os error",
             ErrorKind::UnexpectedEof => "unexpected end of file",
-            ErrorKind::__Nonexhaustive => unreachable!()
         }
     }
 }

src/libstd/lib.rs

@@ -311,6 +311,7 @@
 #![feature(doc_keyword)]
 #![feature(panic_info_message)]
 #![feature(panic_implementation)]
+#![feature(non_exhaustive)]
 
 #![default_lib_allocator]