coverage: Have MakeBcbCounters own its CoverageCounters

Author: Zalathar

compiler/rustc_mir_transform/src/coverage/counters.rs

@@ -80,19 +80,20 @@ impl CoverageCounters {
 basic_coverage_blocks:&CoverageGraph,
 bcb_needs_counter:implFn(BasicCoverageBlock) -> bool,
 ) -> Self{
-let num_bcbs = basic_coverage_blocks.num_nodes();
+letmut counters = MakeBcbCounters::new(basic_coverage_blocks);
+ counters.make_bcb_counters(bcb_needs_counter);
 
-letmut this = Self{
+ counters.coverage_counters
+}
+
+fnwith_num_bcbs(num_bcbs:usize) -> Self{
+Self{
 counter_increment_sites:IndexVec::new(),
 bcb_counters:IndexVec::from_elem_n(None, num_bcbs),
 bcb_edge_counters:FxHashMap::default(),
 expressions:IndexVec::new(),
 expressions_memo:FxHashMap::default(),
-};
-
-MakeBcbCounters::new(&mut this, basic_coverage_blocks).make_bcb_counters(bcb_needs_counter);
-
- this
+}
 }
 
 /// Shared helper used by [`Self::make_phys_node_counter`] and
@@ -265,16 +266,16 @@ impl CoverageCounters {
 
 /// Helper struct that allows counter creation to inspect the BCB graph.
 structMakeBcbCounters<'a>{
-coverage_counters:&'amutCoverageCounters,
+coverage_counters:CoverageCounters,
 basic_coverage_blocks:&'aCoverageGraph,
 }
 
 impl<'a>MakeBcbCounters<'a>{
-fnnew(
-coverage_counters:&'amutCoverageCounters,
-basic_coverage_blocks:&'aCoverageGraph,
-) -> Self{
-Self{ coverage_counters, basic_coverage_blocks }
+fnnew(basic_coverage_blocks:&'aCoverageGraph) -> Self{
+Self{
+coverage_counters:CoverageCounters::with_num_bcbs(basic_coverage_blocks.num_nodes()),
+ basic_coverage_blocks,
+}
 }
 
 fnmake_bcb_counters(&mutself,bcb_needs_counter:implFn(BasicCoverageBlock) -> bool){