Rollup of 12 pull requests

Cargo.lock

@@ -3638,7 +3638,6 @@ dependencies = [
 name = "rustc_infer"
 version = "0.0.0"
 dependencies = [
- "arrayvec",
  "rustc_ast",
  "rustc_data_structures",
  "rustc_errors",
@@ -3778,7 +3777,6 @@ dependencies = [
 name = "rustc_middle"
 version = "0.0.0"
 dependencies = [
- "arrayvec",
  "bitflags",
  "chalk-ir",
  "measureme",

compiler/rustc_data_structures/src/lib.rs

@@ -102,6 +102,7 @@ pub mod work_queue;
 pub use atomic_ref::AtomicRef;
 pub mod frozen;
 pub mod mini_map;
+pub mod mini_set;
 pub mod tagged_ptr;
 pub mod temp_dir;
 pub mod unhash;

compiler/rustc_data_structures/src/mini_set.rs

@@ -0,0 +1,41 @@
+use crate::fx::FxHashSet;
+use arrayvec::ArrayVec;
+use std::hash::Hash;
+/// Small-storage-optimized implementation of a set.
+///
+/// Stores elements in a small array up to a certain length
+/// and switches to `HashSet` when that length is exceeded.
+pub enum MiniSet<T> {
+    Array(ArrayVec<[T; 8]>),
+    Set(FxHashSet<T>),
+}
+
+impl<T: Eq + Hash> MiniSet<T> {
+    /// Creates an empty `MiniSet`.
+    pub fn new() -> Self {
+        MiniSet::Array(ArrayVec::new())
+    }
+
+    /// Adds a value to the set.
+    ///
+    /// If the set did not have this value present, true is returned.
+    ///
+    /// If the set did have this value present, false is returned.
+    pub fn insert(&mut self, elem: T) -> bool {
+        match self {
+            MiniSet::Array(array) => {
+                if array.iter().any(|e| *e == elem) {
+                    false
+                } else {
+                    if let Err(error) = array.try_push(elem) {
+                        let mut set: FxHashSet<T> = array.drain(..).collect();
+                        set.insert(error.element());
+                        *self = MiniSet::Set(set);
+                    }
+                    true
+                }
+            }
+            MiniSet::Set(set) => set.insert(elem),
+        }
+    }
+}

compiler/rustc_driver/src/lib.rs

@@ -1205,9 +1205,9 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     // If backtraces are enabled, also print the query stack
     let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
 
-    if backtrace {
-        TyCtxt::try_print_query_stack(&handler);
-    }
+    let num_frames = if backtrace { None } else { Some(2) };
+
+    TyCtxt::try_print_query_stack(&handler, num_frames);
 
     #[cfg(windows)]
     unsafe {

compiler/rustc_infer/Cargo.toml

@@ -21,5 +21,4 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }
-arrayvec = { version = "0.5.1", default-features = false }
 rustc_ast = { path = "../rustc_ast" }

compiler/rustc_infer/src/infer/outlives/verify.rs

@@ -1,9 +1,9 @@
 use crate::infer::outlives::env::RegionBoundPairs;
 use crate::infer::{GenericKind, VerifyBound};
 use rustc_data_structures::captures::Captures;
+use rustc_data_structures::mini_set::MiniSet;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
-use rustc_middle::ty::walk::MiniSet;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 
 /// The `TypeOutlives` struct has the job of "lowering" a `T: 'a`

compiler/rustc_middle/Cargo.toml

@@ -28,6 +28,5 @@ rustc_ast = { path = "../rustc_ast" }
 rustc_span = { path = "../rustc_span" }
 chalk-ir = "0.21.0"
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }
-arrayvec = { version = "0.5.1", default-features = false }
 measureme = "0.7.1"
 rustc_session = { path = "../rustc_session" }

compiler/rustc_middle/src/ty/outlives.rs

@@ -3,8 +3,8 @@
 // RFC for reference.
 
 use crate::ty::subst::{GenericArg, GenericArgKind};
-use crate::ty::walk::MiniSet;
 use crate::ty::{self, Ty, TyCtxt, TypeFoldable};
+use rustc_data_structures::mini_set::MiniSet;
 use smallvec::SmallVec;
 
 #[derive(Debug)]

compiler/rustc_middle/src/ty/print/mod.rs

@@ -2,9 +2,9 @@ use crate::ty::subst::{GenericArg, Subst};
 use crate::ty::{self, DefIdTree, Ty, TyCtxt};
 
 use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::mini_set::MiniSet;
 use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
-use rustc_middle::ty::walk::MiniSet;
 
 // `pretty` is a separate module only for organization.
 mod pretty;

compiler/rustc_middle/src/ty/query/plumbing.rs

@@ -124,7 +124,7 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    pub fn try_print_query_stack(handler: &Handler) {
+    pub fn try_print_query_stack(handler: &Handler, num_frames: Option<usize>) {
         eprintln!("query stack during panic:");
 
         // Be careful reyling on global state here: this code is called from
@@ -138,6 +138,9 @@ impl<'tcx> TyCtxt<'tcx> {
                 let mut i = 0;
 
                 while let Some(query) = current_query {
+                    if num_frames == Some(i) {
+                        break;
+                    }
                     let query_info =
                         if let Some(info) = query_map.as_ref().and_then(|map| map.get(&query)) {
                             info
@@ -163,7 +166,11 @@ impl<'tcx> TyCtxt<'tcx> {
             }
         });
 
-        eprintln!("end of query stack");
+        if num_frames != None {
+            eprintln!("we're just showing a limited slice of the query stack");
+        } else {
+            eprintln!("end of query stack");
+        }
     }
 }
 

compiler/rustc_middle/src/ty/walk.rs

@@ -3,50 +3,8 @@
 
 use crate::ty;
 use crate::ty::subst::{GenericArg, GenericArgKind};
-use arrayvec::ArrayVec;
-use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::mini_set::MiniSet;
 use smallvec::{self, SmallVec};
-use std::hash::Hash;
-
-/// Small-storage-optimized implementation of a set
-/// made specifically for walking type tree.
-///
-/// Stores elements in a small array up to a certain length
-/// and switches to `HashSet` when that length is exceeded.
-pub enum MiniSet<T> {
-    Array(ArrayVec<[T; 8]>),
-    Set(FxHashSet<T>),
-}
-
-impl<T: Eq + Hash + Copy> MiniSet<T> {
-    /// Creates an empty `MiniSet`.
-    pub fn new() -> Self {
-        MiniSet::Array(ArrayVec::new())
-    }
-
-    /// Adds a value to the set.
-    ///
-    /// If the set did not have this value present, true is returned.
-    ///
-    /// If the set did have this value present, false is returned.
-    pub fn insert(&mut self, elem: T) -> bool {
-        match self {
-            MiniSet::Array(array) => {
-                if array.iter().any(|e| *e == elem) {
-                    false
-                } else {
-                    if array.try_push(elem).is_err() {
-                        let mut set: FxHashSet<T> = array.iter().copied().collect();
-                        set.insert(elem);
-                        *self = MiniSet::Set(set);
-                    }
-                    true
-                }
-            }
-            MiniSet::Set(set) => set.insert(elem),
-        }
-    }
-}
 
 // The TypeWalker's stack is hot enough that it's worth going to some effort to
 // avoid heap allocations.

compiler/rustc_mir/src/transform/dest_prop.rs

@@ -905,7 +905,7 @@ impl<'a, 'tcx> Visitor<'tcx> for FindAssignments<'a, 'tcx> {
             // FIXME: This can be smarter and take `StorageDead` into account (which
             // invalidates borrows).
             if self.ever_borrowed_locals.contains(dest.local)
-                && self.ever_borrowed_locals.contains(src.local)
+                || self.ever_borrowed_locals.contains(src.local)
             {
                 return;
             }

compiler/rustc_mir/src/transform/remove_noop_landing_pads.rs

@@ -102,6 +102,16 @@ impl RemoveNoopLandingPads {
         let postorder: Vec<_> = traversal::postorder(body).map(|(bb, _)| bb).collect();
         for bb in postorder {
             debug!("  processing {:?}", bb);
+            if let Some(unwind) = body[bb].terminator_mut().unwind_mut() {
+                if let Some(unwind_bb) = *unwind {
+                    if nop_landing_pads.contains(unwind_bb) {
+                        debug!("    removing noop landing pad");
+                        landing_pads_removed += 1;
+                        *unwind = None;
+                    }
+                }
+            }
+
             for target in body[bb].terminator_mut().successors_mut() {
                 if *target != resume_block && nop_landing_pads.contains(*target) {
                     debug!("    folding noop jump to {:?} to resume block", target);
@@ -110,15 +120,6 @@ impl RemoveNoopLandingPads {
                 }
             }
 
-            if let Some(unwind) = body[bb].terminator_mut().unwind_mut() {
-                if *unwind == Some(resume_block) {
-                    debug!("    removing noop landing pad");
-                    jumps_folded -= 1;
-                    landing_pads_removed += 1;
-                    *unwind = None;
-                }
-            }
-
             let is_nop_landing_pad = self.is_nop_landing_pad(bb, body, &nop_landing_pads);
             if is_nop_landing_pad {
                 nop_landing_pads.insert(bb);

library/alloc/benches/vec.rs

@@ -241,7 +241,7 @@ fn bench_extend_recycle(b: &mut Bencher) {
     let mut data = vec![0; 1000];
 
     b.iter(|| {
-        let tmp = std::mem::replace(&mut data, Vec::new());
+        let tmp = std::mem::take(&mut data);
         let mut to_extend = black_box(Vec::new());
         to_extend.extend(tmp.into_iter());
         data = black_box(to_extend);
@@ -500,7 +500,7 @@ fn bench_in_place_recycle(b: &mut Bencher) {
     let mut data = vec![0; 1000];
 
     b.iter(|| {
-        let tmp = std::mem::replace(&mut data, Vec::new());
+        let tmp = std::mem::take(&mut data);
         data = black_box(
             tmp.into_iter()
                 .enumerate()
@@ -520,7 +520,7 @@ fn bench_in_place_zip_recycle(b: &mut Bencher) {
     rng.fill_bytes(&mut subst[..]);
 
     b.iter(|| {
-        let tmp = std::mem::replace(&mut data, Vec::new());
+        let tmp = std::mem::take(&mut data);
         let mangled = tmp
             .into_iter()
             .zip(subst.iter().copied())

library/alloc/src/vec.rs

@@ -412,7 +412,7 @@ impl<T> Vec<T> {
     ///   (at least, it's highly likely to be incorrect if it wasn't).
     /// * `T` needs to have the same size and alignment as what `ptr` was allocated with.
     ///   (`T` having a less strict alignment is not sufficient, the alignment really
-    ///   needs to be equal to satsify the [`dealloc`] requirement that memory must be
+    ///   needs to be equal to satisfy the [`dealloc`] requirement that memory must be
     ///   allocated and deallocated with the same layout.)
     /// * `length` needs to be less than or equal to `capacity`.
     /// * `capacity` needs to be the capacity that the pointer was allocated with.

library/core/src/slice/mod.rs

@@ -433,8 +433,9 @@ impl<T> [T] {
     /// assert_eq!(x, &[3, 4, 6]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn as_mut_ptr(&mut self) -> *mut T {
+    pub const fn as_mut_ptr(&mut self) -> *mut T {
         self as *mut [T] as *mut T
     }
 
@@ -469,8 +470,9 @@ impl<T> [T] {
     ///
     /// [`as_ptr`]: #method.as_ptr
     #[unstable(feature = "slice_ptr_range", issue = "65807")]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn as_ptr_range(&self) -> Range<*const T> {
+    pub const fn as_ptr_range(&self) -> Range<*const T> {
         let start = self.as_ptr();
         // SAFETY: The `add` here is safe, because:
         //
@@ -510,8 +512,9 @@ impl<T> [T] {
     ///
     /// [`as_mut_ptr`]: #method.as_mut_ptr
     #[unstable(feature = "slice_ptr_range", issue = "65807")]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn as_mut_ptr_range(&mut self) -> Range<*mut T> {
+    pub const fn as_mut_ptr_range(&mut self) -> Range<*mut T> {
         let start = self.as_mut_ptr();
         // SAFETY: See as_ptr_range() above for why `add` here is safe.
         let end = unsafe { start.add(self.len()) };

library/std/src/lib.rs

@@ -238,6 +238,7 @@
 #![feature(const_cstr_unchecked)]
 #![feature(const_fn_transmute)]
 #![feature(const_fn)]
+#![feature(const_ip)]
 #![feature(const_ipv6)]
 #![feature(const_raw_ptr_deref)]
 #![feature(const_ipv4)]

library/std/src/net/ip.rs

@@ -148,8 +148,9 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)).is_unspecified(), true);
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0)).is_unspecified(), true);
     /// ```
+    #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
     #[stable(feature = "ip_shared", since = "1.12.0")]
-    pub fn is_unspecified(&self) -> bool {
+    pub const fn is_unspecified(&self) -> bool {
         match self {
             IpAddr::V4(ip) => ip.is_unspecified(),
             IpAddr::V6(ip) => ip.is_unspecified(),
@@ -169,8 +170,9 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)).is_loopback(), true);
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0x1)).is_loopback(), true);
     /// ```
+    #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
     #[stable(feature = "ip_shared", since = "1.12.0")]
-    pub fn is_loopback(&self) -> bool {
+    pub const fn is_loopback(&self) -> bool {
         match self {
             IpAddr::V4(ip) => ip.is_loopback(),
             IpAddr::V6(ip) => ip.is_loopback(),
@@ -192,7 +194,8 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(80, 9, 12, 3)).is_global(), true);
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0x1c9, 0, 0, 0xafc8, 0, 0x1)).is_global(), true);
     /// ```
-    pub fn is_global(&self) -> bool {
+    #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
+    pub const fn is_global(&self) -> bool {
         match self {
             IpAddr::V4(ip) => ip.is_global(),
             IpAddr::V6(ip) => ip.is_global(),
@@ -212,8 +215,9 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(224, 254, 0, 0)).is_multicast(), true);
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0xff00, 0, 0, 0, 0, 0, 0, 0)).is_multicast(), true);
     /// ```
+    #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
     #[stable(feature = "ip_shared", since = "1.12.0")]
-    pub fn is_multicast(&self) -> bool {
+    pub const fn is_multicast(&self) -> bool {
         match self {
             IpAddr::V4(ip) => ip.is_multicast(),
             IpAddr::V6(ip) => ip.is_multicast(),
@@ -238,7 +242,8 @@ impl IpAddr {
     ///     true
     /// );
     /// ```
-    pub fn is_documentation(&self) -> bool {
+    #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
+    pub const fn is_documentation(&self) -> bool {
         match self {
             IpAddr::V4(ip) => ip.is_documentation(),
             IpAddr::V6(ip) => ip.is_documentation(),