Auto merge of #89813 - the8472:rollup-f1f99mb, r=the8472

Rollup of 7 pull requests

Successful merges:

 - #89778 (Add #[must_use] to as_type conversions)
 - #89784 (Remove built-in query cache_hit tracking)
 - #89796 (Add #[must_use] to non-mutating verb methods)
 - #89797 (Add #[must_use] to is_condition tests)
 - #89799 (fix minor spelling error in Poll::ready docs)
 - #89800 (Update books)
 - #89809 (Remap ssa RealPredicate to llvm RealPredicate)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_codegen_llvm/src/builder.rs

@@ -828,6 +828,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn fcmp(&mut self, op: RealPredicate, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
+        let op = llvm::RealPredicate::from_generic(op);
         unsafe { llvm::LLVMBuildFCmp(self.llbuilder, op as c_uint, lhs, rhs, UNNAMED) }
     }
 

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -223,6 +223,33 @@ pub enum RealPredicate {
     RealPredicateTrue = 15,
 }
 
+impl RealPredicate {
+    pub fn from_generic(realp: rustc_codegen_ssa::common::RealPredicate) -> Self {
+        match realp {
+            rustc_codegen_ssa::common::RealPredicate::RealPredicateFalse => {
+                RealPredicate::RealPredicateFalse
+            }
+            rustc_codegen_ssa::common::RealPredicate::RealOEQ => RealPredicate::RealOEQ,
+            rustc_codegen_ssa::common::RealPredicate::RealOGT => RealPredicate::RealOGT,
+            rustc_codegen_ssa::common::RealPredicate::RealOGE => RealPredicate::RealOGE,
+            rustc_codegen_ssa::common::RealPredicate::RealOLT => RealPredicate::RealOLT,
+            rustc_codegen_ssa::common::RealPredicate::RealOLE => RealPredicate::RealOLE,
+            rustc_codegen_ssa::common::RealPredicate::RealONE => RealPredicate::RealONE,
+            rustc_codegen_ssa::common::RealPredicate::RealORD => RealPredicate::RealORD,
+            rustc_codegen_ssa::common::RealPredicate::RealUNO => RealPredicate::RealUNO,
+            rustc_codegen_ssa::common::RealPredicate::RealUEQ => RealPredicate::RealUEQ,
+            rustc_codegen_ssa::common::RealPredicate::RealUGT => RealPredicate::RealUGT,
+            rustc_codegen_ssa::common::RealPredicate::RealUGE => RealPredicate::RealUGE,
+            rustc_codegen_ssa::common::RealPredicate::RealULT => RealPredicate::RealULT,
+            rustc_codegen_ssa::common::RealPredicate::RealULE => RealPredicate::RealULE,
+            rustc_codegen_ssa::common::RealPredicate::RealUNE => RealPredicate::RealUNE,
+            rustc_codegen_ssa::common::RealPredicate::RealPredicateTrue => {
+                RealPredicate::RealPredicateTrue
+            }
+        }
+    }
+}
+
 /// LLVMTypeKind
 #[derive(Copy, Clone, PartialEq, Debug)]
 #[repr(C)]

compiler/rustc_query_impl/src/stats.rs

@@ -5,8 +5,6 @@ use rustc_query_system::query::{QueryCache, QueryCacheStore};
 
 use std::any::type_name;
 use std::mem;
-#[cfg(debug_assertions)]
-use std::sync::atomic::Ordering;
 
 trait KeyStats {
     fn key_stats(&self, stats: &mut QueryStats);
@@ -27,7 +25,6 @@ impl KeyStats for DefId {
 #[derive(Clone)]
 struct QueryStats {
     name: &'static str,
-    cache_hits: usize,
     key_size: usize,
     key_type: &'static str,
     value_size: usize,
@@ -42,10 +39,6 @@ where
 {
     let mut stats = QueryStats {
         name,
-        #[cfg(debug_assertions)]
-        cache_hits: map.cache_hits.load(Ordering::Relaxed),
-        #[cfg(not(debug_assertions))]
-        cache_hits: 0,
         key_size: mem::size_of::<C::Key>(),
         key_type: type_name::<C::Key>(),
         value_size: mem::size_of::<C::Value>(),
@@ -63,12 +56,6 @@ where
 pub fn print_stats(tcx: TyCtxt<'_>) {
     let queries = query_stats(tcx);
 
-    if cfg!(debug_assertions) {
-        let hits: usize = queries.iter().map(|s| s.cache_hits).sum();
-        let results: usize = queries.iter().map(|s| s.entry_count).sum();
-        eprintln!("\nQuery cache hit rate: {}", hits as f64 / (hits + results) as f64);
-    }
-
     let mut query_key_sizes = queries.clone();
     query_key_sizes.sort_by_key(|q| q.key_size);
     eprintln!("\nLarge query keys:");
@@ -83,20 +70,6 @@ pub fn print_stats(tcx: TyCtxt<'_>) {
         eprintln!("   {} - {} x {} - {}", q.name, q.value_size, q.entry_count, q.value_type);
     }
 
-    if cfg!(debug_assertions) {
-        let mut query_cache_hits = queries.clone();
-        query_cache_hits.sort_by_key(|q| q.cache_hits);
-        eprintln!("\nQuery cache hits:");
-        for q in query_cache_hits.iter().rev() {
-            eprintln!(
-                "   {} - {} ({}%)",
-                q.name,
-                q.cache_hits,
-                q.cache_hits as f64 / (q.cache_hits + q.entry_count) as f64
-            );
-        }
-    }
-
     let mut query_value_count = queries.clone();
     query_value_count.sort_by_key(|q| q.entry_count);
     eprintln!("\nQuery value count:");

compiler/rustc_query_system/src/query/plumbing.rs

@@ -26,24 +26,15 @@ use std::hash::{Hash, Hasher};
 use std::mem;
 use std::num::NonZeroU32;
 use std::ptr;
-#[cfg(debug_assertions)]
-use std::sync::atomic::{AtomicUsize, Ordering};
 
 pub struct QueryCacheStore<C: QueryCache> {
     cache: C,
     shards: Sharded<C::Sharded>,
-    #[cfg(debug_assertions)]
-    pub cache_hits: AtomicUsize,
 }
 
 impl<C: QueryCache + Default> Default for QueryCacheStore<C> {
     fn default() -> Self {
-        Self {
-            cache: C::default(),
-            shards: Default::default(),
-            #[cfg(debug_assertions)]
-            cache_hits: AtomicUsize::new(0),
-        }
+        Self { cache: C::default(), shards: Default::default() }
     }
 }
 
@@ -377,10 +368,6 @@ where
         if unlikely!(tcx.profiler().enabled()) {
             tcx.profiler().query_cache_hit(index.into());
         }
-        #[cfg(debug_assertions)]
-        {
-            cache.cache_hits.fetch_add(1, Ordering::Relaxed);
-        }
         tcx.dep_graph().read_index(index);
         on_hit(value)
     })
@@ -429,10 +416,6 @@ where
             if unlikely!(tcx.dep_context().profiler().enabled()) {
                 tcx.dep_context().profiler().query_cache_hit(index.into());
             }
-            #[cfg(debug_assertions)]
-            {
-                cache.cache_hits.fetch_add(1, Ordering::Relaxed);
-            }
             query_blocked_prof_timer.finish_with_query_invocation_id(index.into());
 
             (v, Some(index))
@@ -705,10 +688,6 @@ where
         if unlikely!(tcx.dep_context().profiler().enabled()) {
             tcx.dep_context().profiler().query_cache_hit(index.into());
         }
-        #[cfg(debug_assertions)]
-        {
-            cache.cache_hits.fetch_add(1, Ordering::Relaxed);
-        }
     });
 
     let lookup = match cached {

library/alloc/src/collections/binary_heap.rs

@@ -1009,6 +1009,7 @@ impl<T> BinaryHeap<T> {
     ///
     /// io::sink().write(heap.as_slice()).unwrap();
     /// ```
+    #[must_use]
     #[unstable(feature = "binary_heap_as_slice", issue = "83659")]
     pub fn as_slice(&self) -> &[T] {
         self.data.as_slice()

library/alloc/src/collections/linked_list.rs

@@ -1385,6 +1385,7 @@ impl<'a, T> CursorMut<'a, T> {
     /// The lifetime of the returned `Cursor` is bound to that of the
     /// `CursorMut`, which means it cannot outlive the `CursorMut` and that the
     /// `CursorMut` is frozen for the lifetime of the `Cursor`.
+    #[must_use]
     #[unstable(feature = "linked_list_cursors", issue = "58533")]
     pub fn as_cursor(&self) -> Cursor<'_, T> {
         Cursor { list: self.list, current: self.current, index: self.index }

library/alloc/src/rc.rs

@@ -2093,6 +2093,7 @@ impl<T: ?Sized> Weak<T> {
     /// ```
     ///
     /// [`null`]: ptr::null
+    #[must_use]
     #[stable(feature = "rc_as_ptr", since = "1.45.0")]
     pub fn as_ptr(&self) -> *const T {
         let ptr: *mut RcBox<T> = NonNull::as_ptr(self.ptr);
@@ -2229,6 +2230,8 @@ impl<T: ?Sized> Weak<T> {
     ///
     /// assert!(weak_five.upgrade().is_none());
     /// ```
+    #[must_use = "this returns a new `Rc`, \
+                  without modifying the original weak pointer"]
     #[stable(feature = "rc_weak", since = "1.4.0")]
     pub fn upgrade(&self) -> Option<Rc<T>> {
         let inner = self.inner()?;

library/alloc/src/string.rs

@@ -803,6 +803,7 @@ impl String {
     /// assert_eq!("foo", s.as_str());
     /// ```
     #[inline]
+    #[must_use]
     #[stable(feature = "string_as_str", since = "1.7.0")]
     pub fn as_str(&self) -> &str {
         self
@@ -823,6 +824,7 @@ impl String {
     /// assert_eq!("FOOBAR", s_mut_str);
     /// ```
     #[inline]
+    #[must_use]
     #[stable(feature = "string_as_str", since = "1.7.0")]
     pub fn as_mut_str(&mut self) -> &mut str {
         self
@@ -1163,6 +1165,7 @@ impl String {
     /// assert_eq!(&[104, 101, 108, 108, 111], s.as_bytes());
     /// ```
     #[inline]
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn as_bytes(&self) -> &[u8] {
         &self.vec
@@ -1766,6 +1769,7 @@ impl FromUtf8Error {
     ///
     /// assert_eq!(&[0, 159], value.unwrap_err().as_bytes());
     /// ```
+    #[must_use]
     #[stable(feature = "from_utf8_error_as_bytes", since = "1.26.0")]
     pub fn as_bytes(&self) -> &[u8] {
         &self.bytes[..]
@@ -2782,6 +2786,7 @@ impl<'a> Drain<'a> {
     /// let _ = drain.next().unwrap();
     /// assert_eq!(drain.as_str(), "bc");
     /// ```
+    #[must_use]
     #[stable(feature = "string_drain_as_str", since = "1.55.0")]
     pub fn as_str(&self) -> &str {
         self.iter.as_str()

library/alloc/src/sync.rs

@@ -146,7 +146,7 @@ macro_rules! acquire {
 /// use std::sync::Arc;
 ///
 /// let my_arc = Arc::new(());
-/// Arc::downgrade(&my_arc);
+/// let my_weak = Arc::downgrade(&my_arc);
 /// ```
 ///
 /// `Arc<T>`'s implementations of traits like `Clone` may also be called using
@@ -827,6 +827,7 @@ impl<T: ?Sized> Arc<T> {
     /// assert_eq!(x_ptr, Arc::as_ptr(&y));
     /// assert_eq!(unsafe { &*x_ptr }, "hello");
     /// ```
+    #[must_use]
     #[stable(feature = "rc_as_ptr", since = "1.45.0")]
     pub fn as_ptr(this: &Self) -> *const T {
         let ptr: *mut ArcInner<T> = NonNull::as_ptr(this.ptr);
@@ -897,6 +898,8 @@ impl<T: ?Sized> Arc<T> {
     ///
     /// let weak_five = Arc::downgrade(&five);
     /// ```
+    #[must_use = "this returns a new `Weak` pointer, \
+                  without modifying the original `Arc`"]
     #[stable(feature = "arc_weak", since = "1.4.0")]
     pub fn downgrade(this: &Self) -> Weak<T> {
         // This Relaxed is OK because we're checking the value in the CAS
@@ -1724,6 +1727,7 @@ impl<T: ?Sized> Weak<T> {
     /// ```
     ///
     /// [`null`]: core::ptr::null "ptr::null"
+    #[must_use]
     #[stable(feature = "weak_into_raw", since = "1.45.0")]
     pub fn as_ptr(&self) -> *const T {
         let ptr: *mut ArcInner<T> = NonNull::as_ptr(self.ptr);
@@ -1861,6 +1865,8 @@ impl<T: ?Sized> Weak<T> {
     ///
     /// assert!(weak_five.upgrade().is_none());
     /// ```
+    #[must_use = "this returns a new `Arc`, \
+                  without modifying the original weak pointer"]
     #[stable(feature = "arc_weak", since = "1.4.0")]
     pub fn upgrade(&self) -> Option<Arc<T>> {
         // We use a CAS loop to increment the strong count instead of a

library/alloc/src/vec/drain.rs

@@ -52,6 +52,7 @@ impl<'a, T, A: Allocator> Drain<'a, T, A> {
     /// let _ = drain.next().unwrap();
     /// assert_eq!(drain.as_slice(), &['b', 'c']);
     /// ```
+    #[must_use]
     #[stable(feature = "vec_drain_as_slice", since = "1.46.0")]
     pub fn as_slice(&self) -> &[T] {
         self.iter.as_slice()

library/core/src/alloc/layout.rs

@@ -112,6 +112,8 @@ impl Layout {
     /// The minimum byte alignment for a memory block of this layout.
     #[stable(feature = "alloc_layout", since = "1.28.0")]
     #[rustc_const_stable(feature = "const_alloc_layout", since = "1.50.0")]
+    #[must_use = "this returns the minimum alignment, \
+                  without modifying the layout"]
     #[inline]
     pub const fn align(&self) -> usize {
         self.align_.get()
@@ -229,6 +231,8 @@ impl Layout {
     /// satisfy this constraint is to ensure `align <= self.align()`.
     #[unstable(feature = "alloc_layout_extra", issue = "55724")]
     #[rustc_const_unstable(feature = "const_alloc_layout", issue = "67521")]
+    #[must_use = "this returns the padding needed, \
+                  without modifying the `Layout`"]
     #[inline]
     pub const fn padding_needed_for(&self, align: usize) -> usize {
         let len = self.size();
@@ -262,6 +266,8 @@ impl Layout {
     /// This is equivalent to adding the result of `padding_needed_for`
     /// to the layout's current size.
     #[stable(feature = "alloc_layout_manipulation", since = "1.44.0")]
+    #[must_use = "this returns a new `Layout`, \
+                  without modifying the original"]
     #[inline]
     pub fn pad_to_align(&self) -> Layout {
         let pad = self.padding_needed_for(self.align());

library/core/src/fmt/mod.rs

@@ -491,6 +491,7 @@ impl<'a> Arguments<'a> {
     /// ```
     #[stable(feature = "fmt_as_str", since = "1.52.0")]
     #[rustc_const_unstable(feature = "const_arguments_as_str", issue = "none")]
+    #[must_use]
     #[inline]
     pub const fn as_str(&self) -> Option<&'static str> {
         match (self.pieces, self.args) {

library/core/src/option.rs

@@ -657,6 +657,7 @@ impl<T> Option<T> {
     ///
     /// [&]: reference "shared reference"
     #[inline]
+    #[must_use]
     #[stable(feature = "pin", since = "1.33.0")]
     pub fn as_pin_ref(self: Pin<&Self>) -> Option<Pin<&T>> {
         // SAFETY: `x` is guaranteed to be pinned because it comes from `self`
@@ -668,6 +669,7 @@ impl<T> Option<T> {
     ///
     /// [&mut]: reference "mutable reference"
     #[inline]
+    #[must_use]
     #[stable(feature = "pin", since = "1.33.0")]
     pub fn as_pin_mut(self: Pin<&mut Self>) -> Option<Pin<&mut T>> {
         // SAFETY: `get_unchecked_mut` is never used to move the `Option` inside `self`.