Auto merge of #77224 - RalfJung:rollup-hdvb96c, r=RalfJung

Rollup of 12 pull requests

Successful merges:

 - #75454 (Explicitly document the size guarantees that Option makes.)
 - #76631 (Add `x.py setup`)
 - #77076 (Add missing code examples on slice iter types)
 - #77093 (merge `need_type_info_err(_const)`)
 - #77122 (Add `#![feature(const_fn_floating_point_arithmetic)]`)
 - #77127 (Update mdBook)
 - #77161 (Remove TrustedLen requirement from BuilderMethods::switch)
 - #77166 (update Miri)
 - #77181 (Add doc alias for pointer primitive)
 - #77204 (Remove stray word from `ClosureKind::extends` docs)
 - #77207 (Rename `whence` to `span`)
 - #77211 (Remove unused #[allow(...)] statements from compiler/)

Failed merges:

 - #77170 (Remove `#[rustc_allow_const_fn_ptr]` and add `#![feature(const_fn_fn_ptr_basics)]`)

r? `@ghost`

Author: bors

Diff for: Cargo.lock

@@ -1848,9 +1848,9 @@ dependencies = [
 
 [[package]]
 name = "mdbook"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b75e31ae4eaa0e45e17ee2b6b9e3ed969c3c6ff12bb4c2e352c42493f4ebb706"
+checksum = "29be448fcafb00c5a8966c4020c2a5ffbbc333e5b96d0bb5ef54b5bd0524d9ff"
 dependencies = [
  "ammonia",
  "anyhow",

Diff for: compiler/rustc_arena/src/lib.rs

@@ -15,7 +15,6 @@
 #![feature(new_uninit)]
 #![feature(maybe_uninit_slice)]
 #![cfg_attr(test, feature(test))]
-#![allow(deprecated)]
 
 use rustc_data_structures::cold_path;
 use smallvec::SmallVec;

Diff for: compiler/rustc_codegen_llvm/src/builder.rs

@@ -21,7 +21,6 @@ use rustc_target::abi::{self, Align, Size};
 use rustc_target::spec::{HasTargetSpec, Target};
 use std::borrow::Cow;
 use std::ffi::CStr;
-use std::iter::TrustedLen;
 use std::ops::{Deref, Range};
 use std::ptr;
 use tracing::debug;
@@ -179,7 +178,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         &mut self,
         v: &'ll Value,
         else_llbb: &'ll BasicBlock,
-        cases: impl ExactSizeIterator<Item = (u128, &'ll BasicBlock)> + TrustedLen,
+        cases: impl ExactSizeIterator<Item = (u128, &'ll BasicBlock)>,
     ) {
         let switch =
             unsafe { llvm::LLVMBuildSwitch(self.llbuilder, v, else_llbb, cases.len() as c_uint) };
@@ -931,7 +930,6 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         unsafe { llvm::LLVMBuildSelect(self.llbuilder, cond, then_val, else_val, UNNAMED) }
     }
 
-    #[allow(dead_code)]
     fn va_arg(&mut self, list: &'ll Value, ty: &'ll Type) -> &'ll Value {
         unsafe { llvm::LLVMBuildVAArg(self.llbuilder, list, ty, UNNAMED) }
     }

Diff for: compiler/rustc_codegen_llvm/src/common.rs

@@ -1,5 +1,3 @@
-#![allow(non_camel_case_types, non_snake_case)]
-
 //! Code that is useful in various codegen modules.
 
 use crate::consts::{self, const_alloc_to_llvm};

Diff for: compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -1845,7 +1845,6 @@ impl<'tcx> VariantInfo<'_, 'tcx> {
         None
     }
 
-    #[allow(dead_code)]
     fn is_artificial(&self) -> bool {
         match self {
             VariantInfo::Generator { .. } => true,

Diff for: compiler/rustc_codegen_llvm/src/lib.rs

@@ -12,7 +12,6 @@
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
 #![feature(or_patterns)]
-#![feature(trusted_len)]
 #![recursion_limit = "256"]
 
 use back::write::{create_informational_target_machine, create_target_machine};

Diff for: compiler/rustc_codegen_llvm/src/va_arg.rs

@@ -11,7 +11,6 @@ use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::Ty;
 use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Size};
 
-#[allow(dead_code)]
 fn round_pointer_up_to_alignment(
     bx: &mut Builder<'a, 'll, 'tcx>,
     addr: &'ll Value,

Diff for: compiler/rustc_codegen_ssa/src/common.rs

@@ -1,4 +1,4 @@
-#![allow(non_camel_case_types, non_snake_case)]
+#![allow(non_camel_case_types)]
 
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -25,7 +25,6 @@ pub enum IntPredicate {
     IntSLE,
 }
 
-#[allow(dead_code)]
 pub enum RealPredicate {
     RealPredicateFalse,
     RealOEQ,
@@ -60,7 +59,6 @@ pub enum AtomicRmwBinOp {
 }
 
 pub enum AtomicOrdering {
-    #[allow(dead_code)]
     NotAtomic,
     Unordered,
     Monotonic,

Diff for: compiler/rustc_codegen_ssa/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
 #![feature(or_patterns)]
-#![feature(trusted_len)]
 #![feature(associated_type_bounds)]
 #![recursion_limit = "256"]
 

Diff for: compiler/rustc_codegen_ssa/src/traits/builder.rs

@@ -18,7 +18,6 @@ use rustc_middle::ty::Ty;
 use rustc_target::abi::{Abi, Align, Scalar, Size};
 use rustc_target::spec::HasTargetSpec;
 
-use std::iter::TrustedLen;
 use std::ops::Range;
 
 #[derive(Copy, Clone)]
@@ -60,7 +59,7 @@ pub trait BuilderMethods<'a, 'tcx>:
         &mut self,
         v: Self::Value,
         else_llbb: Self::BasicBlock,
-        cases: impl ExactSizeIterator<Item = (u128, Self::BasicBlock)> + TrustedLen,
+        cases: impl ExactSizeIterator<Item = (u128, Self::BasicBlock)>,
     );
     fn invoke(
         &mut self,

Diff for: compiler/rustc_data_structures/src/lib.rs

@@ -7,7 +7,6 @@
 //! This API is completely unstable and subject to change.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
-#![allow(incomplete_features)]
 #![feature(array_windows)]
 #![feature(control_flow_enum)]
 #![feature(in_band_lifetimes)]

Diff for: compiler/rustc_feature/src/active.rs

@@ -584,6 +584,9 @@ declare_features! (
     /// Allows non trivial generic constants which have to be manually propageted upwards.
     (active, const_evaluatable_checked, "1.48.0", Some(76560), None),
 
+    /// Allows basic arithmetic on floating point types in a `const fn`.
+    (active, const_fn_floating_point_arithmetic, "1.48.0", Some(57241), None),
+
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------

Diff for: compiler/rustc_hir/src/intravisit.rs

@@ -256,7 +256,6 @@ pub trait Visitor<'v>: Sized {
     /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
     /// reason to override this method is if you want a nested pattern
     /// but cannot supply a `Map`; see `nested_visit_map` for advice.
-    #[allow(unused_variables)]
     fn visit_nested_item(&mut self, id: ItemId) {
         let opt_item = self.nested_visit_map().inter().map(|map| map.item(id.id));
         walk_list!(self, visit_item, opt_item);
@@ -265,7 +264,6 @@ pub trait Visitor<'v>: Sized {
     /// Like `visit_nested_item()`, but for trait items. See
     /// `visit_nested_item()` for advice on when to override this
     /// method.
-    #[allow(unused_variables)]
     fn visit_nested_trait_item(&mut self, id: TraitItemId) {
         let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
         walk_list!(self, visit_trait_item, opt_item);
@@ -274,7 +272,6 @@ pub trait Visitor<'v>: Sized {
     /// Like `visit_nested_item()`, but for impl items. See
     /// `visit_nested_item()` for advice on when to override this
     /// method.
-    #[allow(unused_variables)]
     fn visit_nested_impl_item(&mut self, id: ImplItemId) {
         let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
         walk_list!(self, visit_impl_item, opt_item);