Auto merge of #73838 - Manishearth:rollup-jj57e84, r=Manishearth

Rollup of 9 pull requests

Successful merges:

 - #73577 (Add partition_point)
 - #73757 (Const prop: erase all block-only locals at the end of every block)
 - #73774 (Make liveness more precise for assignments to fields)
 - #73795 (Add some `const_compare_raw_pointers`-related regression tests)
 - #73800 (Forward Hash::write_iN to Hash::write_uN)
 - #73813 (Rename two `Resolver` traits)
 - #73817 (Rename clashing_extern_decl to clashing_extern_declarations.)
 - #73826 (Fix docstring typo)
 - #73833 (Remove GlobalCtxt::enter_local)

Failed merges:

r? @ghost

Author: bors

src/libcore/hash/mod.rs

@@ -333,31 +333,31 @@ pub trait Hasher {
     #[inline]
     #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i16(&mut self, i: i16) {
-        self.write(&i.to_ne_bytes())
+        self.write_u16(i as u16)
     }
     /// Writes a single `i32` into this hasher.
     #[inline]
     #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i32(&mut self, i: i32) {
-        self.write(&i.to_ne_bytes())
+        self.write_u32(i as u32)
     }
     /// Writes a single `i64` into this hasher.
     #[inline]
     #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_i64(&mut self, i: i64) {
-        self.write(&i.to_ne_bytes())
+        self.write_u64(i as u64)
     }
     /// Writes a single `i128` into this hasher.
     #[inline]
     #[stable(feature = "i128", since = "1.26.0")]
     fn write_i128(&mut self, i: i128) {
-        self.write(&i.to_ne_bytes())
+        self.write_u128(i as u128)
     }
     /// Writes a single `isize` into this hasher.
     #[inline]
     #[stable(feature = "hasher_write", since = "1.3.0")]
     fn write_isize(&mut self, i: isize) {
-        self.write(&i.to_ne_bytes())
+        self.write_usize(i as usize)
     }
 }
 

src/libcore/lib.rs

@@ -279,9 +279,9 @@ pub mod primitive;
 // crate uses the this crate as its libcore.
 #[path = "../stdarch/crates/core_arch/src/mod.rs"]
 #[allow(missing_docs, missing_debug_implementations, dead_code, unused_imports)]
-// FIXME: This annotation should be moved into rust-lang/stdarch after clashing_extern_decl is
+// FIXME: This annotation should be moved into rust-lang/stdarch after clashing_extern_declarations is
 // merged. It currently cannot because bootstrap fails as the lint hasn't been defined yet.
-#[cfg_attr(not(bootstrap), allow(clashing_extern_decl))]
+#[cfg_attr(not(bootstrap), allow(clashing_extern_declarations))]
 #[unstable(feature = "stdsimd", issue = "48556")]
 mod core_arch;
 

src/libcore/slice/mod.rs

@@ -2663,6 +2663,60 @@ impl<T> [T] {
     {
         self.iter().is_sorted_by_key(f)
     }
+
+    /// Returns the index of the partition point according to the given predicate
+    /// (the index of the first element of the second partition).
+    ///
+    /// The slice is assumed to be partitioned according to the given predicate.
+    /// This means that all elements for which the predicate returns true are at the start of the slice
+    /// and all elements for which the predicate returns false are at the end.
+    /// For example, [7, 15, 3, 5, 4, 12, 6] is a partitioned under the predicate x % 2 != 0
+    /// (all odd numbers are at the start, all even at the end).
+    ///
+    /// If this slice is not partitioned, the returned result is unspecified and meaningless,
+    /// as this method performs a kind of binary search.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(partition_point)]
+    ///
+    /// let v = [1, 2, 3, 3, 5, 6, 7];
+    /// let i = v.partition_point(|&x| x < 5);
+    ///
+    /// assert_eq!(i, 4);
+    /// assert!(v[..i].iter().all(|&x| x < 5));
+    /// assert!(v[i..].iter().all(|&x| !(x < 5)));
+    /// ```
+    #[unstable(feature = "partition_point", reason = "new API", issue = "73831")]
+    pub fn partition_point<P>(&self, mut pred: P) -> usize
+    where
+        P: FnMut(&T) -> bool,
+    {
+        let mut left = 0;
+        let mut right = self.len();
+
+        while left != right {
+            let mid = left + (right - left) / 2;
+            // SAFETY:
+            // When left < right, left <= mid < right.
+            // Therefore left always increases and right always decreases,
+            // and eigher of them is selected.
+            // In both cases left <= right is satisfied.
+            // Therefore if left < right in a step,
+            // left <= right is satisfied in the next step.
+            // Therefore as long as left != right, 0 <= left < right <= len is satisfied
+            // and if this case 0 <= mid < len is satisfied too.
+            let value = unsafe { self.get_unchecked(mid) };
+            if pred(value) {
+                left = mid + 1;
+            } else {
+                right = mid;
+            }
+        }
+
+        left
+    }
 }
 
 #[lang = "slice_u8"]

src/libcore/tests/lib.rs

@@ -44,6 +44,7 @@
 #![feature(const_forget)]
 #![feature(option_unwrap_none)]
 #![feature(peekable_next_if)]
+#![feature(partition_point)]
 
 extern crate test;
 

src/libcore/tests/slice.rs

@@ -81,6 +81,46 @@ fn test_binary_search_implementation_details() {
     assert_eq!(b.binary_search(&3), Ok(8));
 }
 
+#[test]
+fn test_partition_point() {
+    let b: [i32; 0] = [];
+    assert_eq!(b.partition_point(|&x| x < 5), 0);
+
+    let b = [4];
+    assert_eq!(b.partition_point(|&x| x < 3), 0);
+    assert_eq!(b.partition_point(|&x| x < 4), 0);
+    assert_eq!(b.partition_point(|&x| x < 5), 1);
+
+    let b = [1, 2, 4, 6, 8, 9];
+    assert_eq!(b.partition_point(|&x| x < 5), 3);
+    assert_eq!(b.partition_point(|&x| x < 6), 3);
+    assert_eq!(b.partition_point(|&x| x < 7), 4);
+    assert_eq!(b.partition_point(|&x| x < 8), 4);
+
+    let b = [1, 2, 4, 5, 6, 8];
+    assert_eq!(b.partition_point(|&x| x < 9), 6);
+
+    let b = [1, 2, 4, 6, 7, 8, 9];
+    assert_eq!(b.partition_point(|&x| x < 6), 3);
+    assert_eq!(b.partition_point(|&x| x < 5), 3);
+    assert_eq!(b.partition_point(|&x| x < 8), 5);
+
+    let b = [1, 2, 4, 5, 6, 8, 9];
+    assert_eq!(b.partition_point(|&x| x < 7), 5);
+    assert_eq!(b.partition_point(|&x| x < 0), 0);
+
+    let b = [1, 3, 3, 3, 7];
+    assert_eq!(b.partition_point(|&x| x < 0), 0);
+    assert_eq!(b.partition_point(|&x| x < 1), 0);
+    assert_eq!(b.partition_point(|&x| x < 2), 1);
+    assert_eq!(b.partition_point(|&x| x < 3), 1);
+    assert_eq!(b.partition_point(|&x| x < 4), 4);
+    assert_eq!(b.partition_point(|&x| x < 5), 4);
+    assert_eq!(b.partition_point(|&x| x < 6), 4);
+    assert_eq!(b.partition_point(|&x| x < 7), 4);
+    assert_eq!(b.partition_point(|&x| x < 8), 5);
+}
+
 #[test]
 fn test_iterator_nth() {
     let v: &[_] = &[0, 1, 2, 3, 4];

src/librustc_ast_lowering/lib.rs

@@ -91,7 +91,7 @@ struct LoweringContext<'a, 'hir: 'a> {
     /// Used to assign IDs to HIR nodes that do not directly correspond to AST nodes.
     sess: &'a Session,
 
-    resolver: &'a mut dyn Resolver,
+    resolver: &'a mut dyn ResolverAstLowering,
 
     /// HACK(Centril): there is a cyclic dependency between the parser and lowering
     /// if we don't have this function pointer. To avoid that dependency so that
@@ -172,7 +172,7 @@ struct LoweringContext<'a, 'hir: 'a> {
     allow_gen_future: Option<Lrc<[Symbol]>>,
 }
 
-pub trait Resolver {
+pub trait ResolverAstLowering {
     fn def_key(&mut self, id: DefId) -> DefKey;
 
     fn item_generics_num_lifetimes(&self, def: DefId, sess: &Session) -> usize;
@@ -299,7 +299,7 @@ impl<'a> ImplTraitContext<'_, 'a> {
 pub fn lower_crate<'a, 'hir>(
     sess: &'a Session,
     krate: &'a Crate,
-    resolver: &'a mut dyn Resolver,
+    resolver: &'a mut dyn ResolverAstLowering,
     nt_to_tokenstream: NtToTokenstream,
     arena: &'hir Arena<'hir>,
 ) -> hir::Crate<'hir> {

src/librustc_builtin_macros/lib.rs

@@ -15,7 +15,7 @@ extern crate proc_macro;
 
 use crate::deriving::*;
 
-use rustc_expand::base::{MacroExpanderFn, Resolver, SyntaxExtension, SyntaxExtensionKind};
+use rustc_expand::base::{MacroExpanderFn, ResolverExpand, SyntaxExtension, SyntaxExtensionKind};
 use rustc_expand::proc_macro::BangProcMacro;
 use rustc_span::edition::Edition;
 use rustc_span::symbol::{sym, Ident};
@@ -45,7 +45,7 @@ pub mod proc_macro_harness;
 pub mod standard_library_imports;
 pub mod test_harness;
 
-pub fn register_builtin_macros(resolver: &mut dyn Resolver, edition: Edition) {
+pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand, edition: Edition) {
     let mut register = |name, kind| {
         resolver.register_builtin_macro(
             Ident::with_dummy_span(name),

src/librustc_builtin_macros/proc_macro_harness.rs

@@ -6,7 +6,7 @@ use rustc_ast::expand::is_proc_macro_attr;
 use rustc_ast::ptr::P;
 use rustc_ast::visit::{self, Visitor};
 use rustc_ast_pretty::pprust;
-use rustc_expand::base::{ExtCtxt, Resolver};
+use rustc_expand::base::{ExtCtxt, ResolverExpand};
 use rustc_expand::expand::{AstFragment, ExpansionConfig};
 use rustc_session::parse::ParseSess;
 use rustc_span::hygiene::AstPass;
@@ -52,7 +52,7 @@ struct CollectProcMacros<'a> {
 
 pub fn inject(
     sess: &ParseSess,
-    resolver: &mut dyn Resolver,
+    resolver: &mut dyn ResolverExpand,
     mut krate: ast::Crate,
     is_proc_macro_crate: bool,
     has_proc_macro_decls: bool,

src/librustc_builtin_macros/standard_library_imports.rs

@@ -1,6 +1,6 @@
 use rustc_ast::ptr::P;
 use rustc_ast::{ast, attr};
-use rustc_expand::base::{ExtCtxt, Resolver};
+use rustc_expand::base::{ExtCtxt, ResolverExpand};
 use rustc_expand::expand::ExpansionConfig;
 use rustc_session::parse::ParseSess;
 use rustc_span::edition::Edition;
@@ -10,7 +10,7 @@ use rustc_span::DUMMY_SP;
 
 pub fn inject(
     mut krate: ast::Crate,
-    resolver: &mut dyn Resolver,
+    resolver: &mut dyn ResolverExpand,
     sess: &ParseSess,
     alt_std_name: Option<Symbol>,
 ) -> (ast::Crate, Option<Symbol>) {

src/librustc_builtin_macros/test_harness.rs

@@ -6,7 +6,7 @@ use rustc_ast::attr;
 use rustc_ast::entry::{self, EntryPointType};
 use rustc_ast::mut_visit::{ExpectOne, *};
 use rustc_ast::ptr::P;
-use rustc_expand::base::{ExtCtxt, Resolver};
+use rustc_expand::base::{ExtCtxt, ResolverExpand};
 use rustc_expand::expand::{AstFragment, ExpansionConfig};
 use rustc_feature::Features;
 use rustc_session::parse::ParseSess;
@@ -37,7 +37,7 @@ struct TestCtxt<'a> {
 // existing main functions, and synthesizing a main test harness
 pub fn inject(
     sess: &ParseSess,
-    resolver: &mut dyn Resolver,
+    resolver: &mut dyn ResolverExpand,
     should_test: bool,
     krate: &mut ast::Crate,
     span_diagnostic: &rustc_errors::Handler,
@@ -192,7 +192,7 @@ impl MutVisitor for EntryPointCleaner {
 /// Crawl over the crate, inserting test reexports and the test main function
 fn generate_test_harness(
     sess: &ParseSess,
-    resolver: &mut dyn Resolver,
+    resolver: &mut dyn ResolverExpand,
     reexport_test_harness_main: Option<Symbol>,
     krate: &mut ast::Crate,
     features: &Features,