Unrolled build for rust-lang#135205

Rollup merge of rust-lang#135205 - lqd:bitsets, r=Mark-Simulacrum

Rename `BitSet` to `DenseBitSet`

r? `@Mark-Simulacrum` as you requested this in rust-lang#134438 (comment) after such a confusion.

This PR renames `BitSet` to `DenseBitSet` to make it less obvious as the go-to solution for bitmap needs, as well as make its representation (and positives/negatives) clearer. It also expands the comments there to hopefully make it clearer when it's not a good fit, with some alternative bitsets types.

(This migrates the subtrees cg_gcc and clippy to use the new name in separate commits, for easier review by their respective owners, but they can obvs be squashed)

Author: rust-timer

compiler/rustc_borrowck/src/borrow_set.rs

@@ -2,7 +2,7 @@ use std::fmt;
 use std::ops::Index;
 
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
-use rustc_index::bit_set::BitSet;
+use rustc_index::bit_set::DenseBitSet;
 use rustc_middle::mir::visit::{MutatingUseContext, NonUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::{self, Body, Local, Location, traversal};
 use rustc_middle::span_bug;
@@ -131,7 +131,7 @@ impl<'tcx> fmt::Display for BorrowData<'tcx> {
 
 pub enum LocalsStateAtExit {
     AllAreInvalidated,
-    SomeAreInvalidated { has_storage_dead_or_moved: BitSet<Local> },
+    SomeAreInvalidated { has_storage_dead_or_moved: DenseBitSet<Local> },
 }
 
 impl LocalsStateAtExit {
@@ -140,7 +140,7 @@ impl LocalsStateAtExit {
         body: &Body<'tcx>,
         move_data: &MoveData<'tcx>,
     ) -> Self {
-        struct HasStorageDead(BitSet<Local>);
+        struct HasStorageDead(DenseBitSet<Local>);
 
         impl<'tcx> Visitor<'tcx> for HasStorageDead {
             fn visit_local(&mut self, local: Local, ctx: PlaceContext, _: Location) {
@@ -153,7 +153,8 @@ impl LocalsStateAtExit {
         if locals_are_invalidated_at_exit {
             LocalsStateAtExit::AllAreInvalidated
         } else {
-            let mut has_storage_dead = HasStorageDead(BitSet::new_empty(body.local_decls.len()));
+            let mut has_storage_dead =
+                HasStorageDead(DenseBitSet::new_empty(body.local_decls.len()));
             has_storage_dead.visit_body(body);
             let mut has_storage_dead_or_moved = has_storage_dead.0;
             for move_out in &move_data.moves {

compiler/rustc_borrowck/src/dataflow.rs

@@ -2,7 +2,7 @@ use std::fmt;
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::graph;
-use rustc_index::bit_set::BitSet;
+use rustc_index::bit_set::DenseBitSet;
 use rustc_middle::mir::{
     self, BasicBlock, Body, CallReturnPlaces, Location, Place, TerminatorEdges,
 };
@@ -180,7 +180,7 @@ pub struct Borrows<'a, 'tcx> {
 }
 
 struct OutOfScopePrecomputer<'a, 'tcx> {
-    visited: BitSet<mir::BasicBlock>,
+    visited: DenseBitSet<mir::BasicBlock>,
     visit_stack: Vec<mir::BasicBlock>,
     body: &'a Body<'tcx>,
     regioncx: &'a RegionInferenceContext<'tcx>,
@@ -190,7 +190,7 @@ struct OutOfScopePrecomputer<'a, 'tcx> {
 impl<'a, 'tcx> OutOfScopePrecomputer<'a, 'tcx> {
     fn new(body: &'a Body<'tcx>, regioncx: &'a RegionInferenceContext<'tcx>) -> Self {
         OutOfScopePrecomputer {
-            visited: BitSet::new_empty(body.basic_blocks.len()),
+            visited: DenseBitSet::new_empty(body.basic_blocks.len()),
             visit_stack: vec![],
             body,
             regioncx,
@@ -292,7 +292,7 @@ pub fn calculate_borrows_out_of_scope_at_location<'tcx>(
 }
 
 struct PoloniusOutOfScopePrecomputer<'a, 'tcx> {
-    visited: BitSet<mir::BasicBlock>,
+    visited: DenseBitSet<mir::BasicBlock>,
     visit_stack: Vec<mir::BasicBlock>,
     body: &'a Body<'tcx>,
     regioncx: &'a RegionInferenceContext<'tcx>,
@@ -303,7 +303,7 @@ struct PoloniusOutOfScopePrecomputer<'a, 'tcx> {
 impl<'a, 'tcx> PoloniusOutOfScopePrecomputer<'a, 'tcx> {
     fn new(body: &'a Body<'tcx>, regioncx: &'a RegionInferenceContext<'tcx>) -> Self {
         Self {
-            visited: BitSet::new_empty(body.basic_blocks.len()),
+            visited: DenseBitSet::new_empty(body.basic_blocks.len()),
             visit_stack: vec![],
             body,
             regioncx,
@@ -559,7 +559,7 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     }
 }
 
-type BorrowsDomain = BitSet<BorrowIndex>;
+type BorrowsDomain = DenseBitSet<BorrowIndex>;
 
 /// Forward dataflow computation of the set of borrows that are in scope at a particular location.
 /// - we gen the introduced loans
@@ -575,7 +575,7 @@ impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
 
     fn bottom_value(&self, _: &mir::Body<'tcx>) -> Self::Domain {
         // bottom = nothing is reserved or activated yet;
-        BitSet::new_empty(self.borrow_set.len())
+        DenseBitSet::new_empty(self.borrow_set.len())
     }
 
     fn initialize_start_block(&self, _: &mir::Body<'tcx>, _: &mut Self::Domain) {