Rollup merge of rust-lang#107153 - tmiasko:dominates, r=oli-obk

Consistently use dominates instead of is_dominated_by

There is a number of APIs that answer dominance queries. Previously they were named either "dominates" or "is_dominated_by". Consistently use the "dominates" form.

No functional changes.

Author: JohnTitor

compiler/rustc_data_structures/src/graph/dominators/mod.rs

@@ -285,7 +285,7 @@ impl<Node: Idx> Dominators<Node> {
         Iter { dominators: self, node: Some(node) }
     }
 
-    pub fn is_dominated_by(&self, node: Node, dom: Node) -> bool {
+    pub fn dominates(&self, dom: Node, node: Node) -> bool {
         // FIXME -- could be optimized by using post-order-rank
         self.dominators(node).any(|n| n == dom)
     }

compiler/rustc_middle/src/mir/mod.rs

@@ -3046,7 +3046,7 @@ impl Location {
         if self.block == other.block {
             self.statement_index <= other.statement_index
         } else {
-            dominators.is_dominated_by(other.block, self.block)
+            dominators.dominates(self.block, other.block)
         }
     }
 }

compiler/rustc_mir_transform/src/coverage/counters.rs

@@ -520,7 +520,7 @@ impl<'a> BcbCounters<'a> {
                 let mut found_loop_exit = false;
                 for &branch in branches.iter() {
                     if backedge_from_bcbs.iter().any(|&backedge_from_bcb| {
-                        self.bcb_is_dominated_by(backedge_from_bcb, branch.target_bcb)
+                        self.bcb_dominates(branch.target_bcb, backedge_from_bcb)
                     }) {
                         if let Some(reloop_branch) = some_reloop_branch {
                             if reloop_branch.counter(&self.basic_coverage_blocks).is_none() {
@@ -603,8 +603,8 @@ impl<'a> BcbCounters<'a> {
     }
 
     #[inline]
-    fn bcb_is_dominated_by(&self, node: BasicCoverageBlock, dom: BasicCoverageBlock) -> bool {
-        self.basic_coverage_blocks.is_dominated_by(node, dom)
+    fn bcb_dominates(&self, dom: BasicCoverageBlock, node: BasicCoverageBlock) -> bool {
+        self.basic_coverage_blocks.dominates(dom, node)
     }
 
     #[inline]

compiler/rustc_mir_transform/src/coverage/graph.rs

@@ -209,8 +209,8 @@ impl CoverageGraph {
     }
 
     #[inline(always)]
-    pub fn is_dominated_by(&self, node: BasicCoverageBlock, dom: BasicCoverageBlock) -> bool {
-        self.dominators.as_ref().unwrap().is_dominated_by(node, dom)
+    pub fn dominates(&self, dom: BasicCoverageBlock, node: BasicCoverageBlock) -> bool {
+        self.dominators.as_ref().unwrap().dominates(dom, node)
     }
 
     #[inline(always)]
@@ -312,7 +312,7 @@ rustc_index::newtype_index! {
 /// to the BCB's primary counter or expression).
 ///
 /// The BCB CFG is critical to simplifying the coverage analysis by ensuring graph path-based
-/// queries (`is_dominated_by()`, `predecessors`, `successors`, etc.) have branch (control flow)
+/// queries (`dominates()`, `predecessors`, `successors`, etc.) have branch (control flow)
 /// significance.
 #[derive(Debug, Clone)]
 pub(super) struct BasicCoverageBlockData {
@@ -594,7 +594,7 @@ impl TraverseCoverageGraphWithLoops {
                 // branching block would have given an `Expression` (or vice versa).
                 let (some_successor_to_add, some_loop_header) =
                     if let Some((_, loop_header)) = context.loop_backedges {
-                        if basic_coverage_blocks.is_dominated_by(successor, loop_header) {
+                        if basic_coverage_blocks.dominates(loop_header, successor) {
                             (Some(successor), Some(loop_header))
                         } else {
                             (None, None)
@@ -666,15 +666,15 @@ pub(super) fn find_loop_backedges(
     //
     // The overall complexity appears to be comparable to many other MIR transform algorithms, and I
     // don't expect that this function is creating a performance hot spot, but if this becomes an
-    // issue, there may be ways to optimize the `is_dominated_by` algorithm (as indicated by an
+    // issue, there may be ways to optimize the `dominates` algorithm (as indicated by an
     // existing `FIXME` comment in that code), or possibly ways to optimize it's usage here, perhaps
     // by keeping track of results for visited `BasicCoverageBlock`s if they can be used to short
-    // circuit downstream `is_dominated_by` checks.
+    // circuit downstream `dominates` checks.
     //
     // For now, that kind of optimization seems unnecessarily complicated.
     for (bcb, _) in basic_coverage_blocks.iter_enumerated() {
         for &successor in &basic_coverage_blocks.successors[bcb] {
-            if basic_coverage_blocks.is_dominated_by(bcb, successor) {
+            if basic_coverage_blocks.dominates(successor, bcb) {
                 let loop_header = successor;
                 let backedge_from_bcb = bcb;
                 debug!(

compiler/rustc_mir_transform/src/coverage/spans.rs

@@ -63,7 +63,7 @@ impl CoverageStatement {
 /// Note: A `CoverageStatement` merged into another CoverageSpan may come from a `BasicBlock` that
 /// is not part of the `CoverageSpan` bcb if the statement was included because it's `Span` matches
 /// or is subsumed by the `Span` associated with this `CoverageSpan`, and it's `BasicBlock`
-/// `is_dominated_by()` the `BasicBlock`s in this `CoverageSpan`.
+/// `dominates()` the `BasicBlock`s in this `CoverageSpan`.
 #[derive(Debug, Clone)]
 pub(super) struct CoverageSpan {
     pub span: Span,
@@ -705,12 +705,12 @@ impl<'a, 'tcx> CoverageSpans<'a, 'tcx> {
     fn hold_pending_dups_unless_dominated(&mut self) {
         // Equal coverage spans are ordered by dominators before dominated (if any), so it should be
         // impossible for `curr` to dominate any previous `CoverageSpan`.
-        debug_assert!(!self.span_bcb_is_dominated_by(self.prev(), self.curr()));
+        debug_assert!(!self.span_bcb_dominates(self.curr(), self.prev()));
 
         let initial_pending_count = self.pending_dups.len();
         if initial_pending_count > 0 {
             let mut pending_dups = self.pending_dups.split_off(0);
-            pending_dups.retain(|dup| !self.span_bcb_is_dominated_by(self.curr(), dup));
+            pending_dups.retain(|dup| !self.span_bcb_dominates(dup, self.curr()));
             self.pending_dups.append(&mut pending_dups);
             if self.pending_dups.len() < initial_pending_count {
                 debug!(
@@ -721,7 +721,7 @@ impl<'a, 'tcx> CoverageSpans<'a, 'tcx> {
             }
         }
 
-        if self.span_bcb_is_dominated_by(self.curr(), self.prev()) {
+        if self.span_bcb_dominates(self.prev(), self.curr()) {
             debug!(
                 "  different bcbs but SAME spans, and prev dominates curr. Discard prev={:?}",
                 self.prev()
@@ -787,8 +787,8 @@ impl<'a, 'tcx> CoverageSpans<'a, 'tcx> {
         }
     }
 
-    fn span_bcb_is_dominated_by(&self, covspan: &CoverageSpan, dom_covspan: &CoverageSpan) -> bool {
-        self.basic_coverage_blocks.is_dominated_by(covspan.bcb, dom_covspan.bcb)
+    fn span_bcb_dominates(&self, dom_covspan: &CoverageSpan, covspan: &CoverageSpan) -> bool {
+        self.basic_coverage_blocks.dominates(dom_covspan.bcb, covspan.bcb)
     }
 }