Auto merge of #64026 - Centril:rollup-le667lp, r=Centril

Rollup of 7 pull requests

Successful merges:

 - #62957 (Match the loop examples)
 - #63600 (Merge oli-obk mail addresses)
 - #63684 (Constify LinkedList new function)
 - #63847 ([rustdoc] Fix system theme detection)
 - #63999 (Add missing links on AsRef trait)
 - #64014 ( miri: detect too large dynamically sized objects )
 - #64015 (some const-eval test tweaks)

Failed merges:

r? @ghost

Author: bors

.mailmap

@@ -184,12 +184,19 @@ Neil Pankey <[email protected]> <[email protected]>
 Nick Platt <[email protected]>
 Nicole Mazzuca <[email protected]>
 Nif Ward <[email protected]>
-Oliver Schneider <[email protected]> oli-obk <[email protected]>
-Oliver Schneider <[email protected]> Oliver 'ker' Schneider <[email protected]>
-Oliver Schneider <[email protected]> Oliver Schneider <[email protected]>
-Oliver Schneider <[email protected]> Oliver Schneider <[email protected]>
-Oliver Schneider <[email protected]> Oliver Schneider <[email protected]>
-Oliver Schneider <[email protected]> Oliver Schneider <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]> <[email protected]>
+Oliver Scherer <[email protected]>
 Ožbolt Menegatti <[email protected]> gareins <[email protected]>
 Paul Faria <[email protected]> Paul Faria <[email protected]>
 Peer Aramillo Irizar <[email protected]> parir <[email protected]>

src/liballoc/collections/linked_list.rs

@@ -276,7 +276,7 @@ impl<T> LinkedList<T> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         LinkedList {
             head: None,
             tail: None,

src/libcore/convert.rs

@@ -104,22 +104,17 @@ pub const fn identity<T>(x: T) -> T { x }
 /// If you need to do a costly conversion it is better to implement [`From`] with type
 /// `&T` or write a custom function.
 ///
-/// `AsRef` has the same signature as [`Borrow`], but `Borrow` is different in few aspects:
+/// `AsRef` has the same signature as [`Borrow`], but [`Borrow`] is different in few aspects:
 ///
-/// - Unlike `AsRef`, `Borrow` has a blanket impl for any `T`, and can be used to accept either
+/// - Unlike `AsRef`, [`Borrow`] has a blanket impl for any `T`, and can be used to accept either
 ///   a reference or a value.
-/// - `Borrow` also requires that `Hash`, `Eq` and `Ord` for borrowed value are
+/// - [`Borrow`] also requires that [`Hash`], [`Eq`] and [`Ord`] for borrowed value are
 ///   equivalent to those of the owned value. For this reason, if you want to
-///   borrow only a single field of a struct you can implement `AsRef`, but not `Borrow`.
-///
-/// [`Borrow`]: ../../std/borrow/trait.Borrow.html
+///   borrow only a single field of a struct you can implement `AsRef`, but not [`Borrow`].
 ///
 /// **Note: This trait must not fail**. If the conversion can fail, use a
 /// dedicated method which returns an [`Option<T>`] or a [`Result<T, E>`].
 ///
-/// [`Option<T>`]: ../../std/option/enum.Option.html
-/// [`Result<T, E>`]: ../../std/result/enum.Result.html
-///
 /// # Generic Implementations
 ///
 /// - `AsRef` auto-dereferences if the inner type is a reference or a mutable
@@ -132,9 +127,16 @@ pub const fn identity<T>(x: T) -> T { x }
 /// converted to the specified type `T`.
 ///
 /// For example: By creating a generic function that takes an `AsRef<str>` we express that we
-/// want to accept all references that can be converted to `&str` as an argument.
-/// Since both [`String`] and `&str` implement `AsRef<str>` we can accept both as input argument.
+/// want to accept all references that can be converted to [`&str`] as an argument.
+/// Since both [`String`] and [`&str`] implement `AsRef<str>` we can accept both as input argument.
 ///
+/// [`Option<T>`]: ../../std/option/enum.Option.html
+/// [`Result<T, E>`]: ../../std/result/enum.Result.html
+/// [`Borrow`]: ../../std/borrow/trait.Borrow.html
+/// [`Hash`]: ../../std/hash/trait.Hash.html
+/// [`Eq`]: ../../std/cmp/trait.Eq.html
+/// [`Ord`]: ../../std/cmp/trait.Ord.html
+/// [`&str`]: ../../std/primitive.str.html
 /// [`String`]: ../../std/string/struct.String.html
 ///
 /// ```

src/librustc_mir/interpret/eval_context.rs

@@ -442,27 +442,30 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
                 // Issue #27023: must add any necessary padding to `size`
                 // (to make it a multiple of `align`) before returning it.
-                //
-                // Namely, the returned size should be, in C notation:
-                //
-                //   `size + ((size & (align-1)) ? align : 0)`
-                //
-                // emulated via the semi-standard fast bit trick:
-                //
-                //   `(size + (align-1)) & -align`
-
-                Ok(Some((size.align_to(align), align)))
+                let size = size.align_to(align);
+
+                // Check if this brought us over the size limit.
+                if size.bytes() >= self.tcx.data_layout().obj_size_bound() {
+                    throw_ub_format!("wide pointer metadata contains invalid information: \
+                        total size is bigger than largest supported object");
+                }
+                Ok(Some((size, align)))
             }
             ty::Dynamic(..) => {
                 let vtable = metadata.expect("dyn trait fat ptr must have vtable");
-                // the second entry in the vtable is the dynamic size of the object.
+                // Read size and align from vtable (already checks size).
                 Ok(Some(self.read_size_and_align_from_vtable(vtable)?))
             }
 
             ty::Slice(_) | ty::Str => {
                 let len = metadata.expect("slice fat ptr must have vtable").to_usize(self)?;
                 let elem = layout.field(self, 0)?;
-                Ok(Some((elem.size * len, elem.align.abi)))
+
+                // Make sure the slice is not too big.
+                let size = elem.size.checked_mul(len, &*self.tcx)
+                    .ok_or_else(|| err_ub_format!("invalid slice: \
+                        total size is bigger than largest supported object"))?;
+                Ok(Some((size, elem.align.abi)))
             }
 
             ty::Foreign(_) => {

src/librustc_mir/interpret/traits.rs

@@ -1,5 +1,5 @@
 use rustc::ty::{self, Ty, Instance, TypeFoldable};
-use rustc::ty::layout::{Size, Align, LayoutOf};
+use rustc::ty::layout::{Size, Align, LayoutOf, HasDataLayout};
 use rustc::mir::interpret::{Scalar, Pointer, InterpResult, PointerArithmetic,};
 
 use super::{InterpCx, Machine, MemoryKind, FnVal};
@@ -151,6 +151,11 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             vtable.offset(pointer_size * 2, self)?,
         )?.not_undef()?;
         let align = self.force_bits(align, pointer_size)? as u64;
+
+        if size >= self.tcx.data_layout().obj_size_bound() {
+            throw_ub_format!("invalid vtable: \
+                size is bigger than largest supported object");
+        }
         Ok((Size::from_bytes(size), Align::from_bytes(align).unwrap()))
     }
 }

src/librustc_mir/interpret/validity.rs

@@ -1,3 +1,9 @@
+//! Check the validity invariant of a given value, and tell the user
+//! where in the value it got violated.
+//! In const context, this goes even further and tries to approximate const safety.
+//! That's useful because it means other passes (e.g. promotion) can rely on `const`s
+//! to be const-safe.
+
 use std::fmt::Write;
 use std::ops::RangeInclusive;
 

src/librustdoc/html/static/storage.js

@@ -118,7 +118,8 @@ function switchTheme(styleElem, mainStyleElem, newTheme, saveTheme) {
 }
 
 function getSystemValue() {
-    return getComputedStyle(document.documentElement).getPropertyValue('content');
+    var property = getComputedStyle(document.documentElement).getPropertyValue('content');
+    return property.replace(/\"\'/g, "");
 }
 
 switchTheme(currentTheme, mainTheme,

src/libstd/keyword_docs.rs

@@ -681,14 +681,15 @@ mod while_keyword { }
 ///     # break;
 /// }
 ///
-/// let mut i = 0;
+/// let mut i = 1;
 /// loop {
 ///     println!("i is {}", i);
-///     if i > 10 {
+///     if i > 100 {
 ///         break;
 ///     }
-///     i += 1;
+///     i *= 2;
 /// }
+/// assert_eq!(i, 128);
 /// ```
 ///
 /// Unlike the other kinds of loops in Rust (`while`, `while let`, and `for`), loops can be used as

src/test/ui/consts/const-eval/const-pointer-values-in-various-types.rs

@@ -1,5 +1,6 @@
 // only-x86_64
 
+#[repr(C)]
 union Nonsense {
     u: usize,
     int_32_ref: &'static i32,