coverage: Give the instrumentor its own counter type, separate from MIR

This splits off `BcbCounter` from MIR's `CoverageKind`, allowing the two types
to evolve in different directions as necessary.

1 files changed, 34 insertions, 35 deletions

diff --git a/compiler/rustc_mir_transform/src/coverage/debug.rs b/compiler/rustc_mir_transform/src/coverage/debug.rs
index 083f1f8aef6..af616c498fd 100644
--- a/compiler/rustc_mir_transform/src/coverage/debug.rs
+++ b/compiler/rustc_mir_transform/src/coverage/debug.rs
@@ -108,7 +108,7 @@
 //!         recursively, generating labels with nested operations, enclosed in parentheses
 //!         (for example: `bcb2 + (bcb0 - bcb1)`).
 
-use super::counters::CoverageCounters;
+use super::counters::{BcbCounter, CoverageCounters};
 use super::graph::{BasicCoverageBlock, BasicCoverageBlockData, CoverageGraph};
 use super::spans::CoverageSpan;
 
@@ -247,11 +247,11 @@ impl Default for ExpressionFormat {
     }
 }
 
-/// If enabled, this struct maintains a map from `CoverageKind` IDs (as `Operand`) to
-/// the `CoverageKind` data and optional label (normally, the counter's associated
+/// If enabled, this struct maintains a map from `BcbCounter` IDs (as `Operand`) to
+/// the `BcbCounter` data and optional label (normally, the counter's associated
 /// `BasicCoverageBlock` format string, if any).
 ///
-/// Use `format_counter` to convert one of these `CoverageKind` counters to a debug output string,
+/// Use `format_counter` to convert one of these `BcbCounter` counters to a debug output string,
 /// as directed by the `DebugOptions`. This allows the format of counter labels in logs and dump
 /// files (including the `CoverageGraph` graphviz file) to be changed at runtime, via environment
 /// variable.
@@ -276,7 +276,7 @@ impl DebugCounters {
         self.some_counters.is_some()
     }
 
-    pub fn add_counter(&mut self, counter_kind: &CoverageKind, some_block_label: Option<String>) {
+    pub fn add_counter(&mut self, counter_kind: &BcbCounter, some_block_label: Option<String>) {
         if let Some(counters) = &mut self.some_counters {
             let id = counter_kind.as_operand();
             counters
@@ -291,21 +291,20 @@ impl DebugCounters {
         })
     }
 
-    pub fn format_counter(&self, counter_kind: &CoverageKind) -> String {
+    pub fn format_counter(&self, counter_kind: &BcbCounter) -> String {
         match *counter_kind {
-            CoverageKind::Counter { .. } => {
+            BcbCounter::Counter { .. } => {
                 format!("Counter({})", self.format_counter_kind(counter_kind))
             }
-            CoverageKind::Expression { .. } => {
+            BcbCounter::Expression { .. } => {
                 format!("Expression({})", self.format_counter_kind(counter_kind))
             }
-            CoverageKind::Unreachable { .. } => "Unreachable".to_owned(),
         }
     }
 
-    fn format_counter_kind(&self, counter_kind: &CoverageKind) -> String {
+    fn format_counter_kind(&self, counter_kind: &BcbCounter) -> String {
         let counter_format = &debug_options().counter_format;
-        if let CoverageKind::Expression { id, lhs, op, rhs } = *counter_kind {
+        if let BcbCounter::Expression { id, lhs, op, rhs } = *counter_kind {
             if counter_format.operation {
                 return format!(
                     "{}{} {} {}",
@@ -346,7 +345,7 @@ impl DebugCounters {
         }
         if let Some(counters) = &self.some_counters {
             if let Some(DebugCounter { counter_kind, some_block_label }) = counters.get(&operand) {
-                if let CoverageKind::Expression { .. } = counter_kind {
+                if let BcbCounter::Expression { .. } = counter_kind {
                     if let Some(label) = some_block_label && debug_options().counter_format.block {
                         return format!(
                             "{}:({})",
@@ -366,12 +365,12 @@ impl DebugCounters {
 /// A non-public support class to `DebugCounters`.
 #[derive(Debug)]
 struct DebugCounter {
-    counter_kind: CoverageKind,
+    counter_kind: BcbCounter,
     some_block_label: Option<String>,
 }
 
 impl DebugCounter {
-    fn new(counter_kind: CoverageKind, some_block_label: Option<String>) -> Self {
+    fn new(counter_kind: BcbCounter, some_block_label: Option<String>) -> Self {
         Self { counter_kind, some_block_label }
     }
 }
@@ -380,9 +379,9 @@ impl DebugCounter {
 /// a Graphviz (.dot file) representation of the `CoverageGraph`, for debugging purposes.
 pub(super) struct GraphvizData {
     some_bcb_to_coverage_spans_with_counters:
-        Option<FxHashMap<BasicCoverageBlock, Vec<(CoverageSpan, CoverageKind)>>>,
-    some_bcb_to_dependency_counters: Option<FxHashMap<BasicCoverageBlock, Vec<CoverageKind>>>,
-    some_edge_to_counter: Option<FxHashMap<(BasicCoverageBlock, BasicBlock), CoverageKind>>,
+        Option<FxHashMap<BasicCoverageBlock, Vec<(CoverageSpan, BcbCounter)>>>,
+    some_bcb_to_dependency_counters: Option<FxHashMap<BasicCoverageBlock, Vec<BcbCounter>>>,
+    some_edge_to_counter: Option<FxHashMap<(BasicCoverageBlock, BasicBlock), BcbCounter>>,
 }
 
 impl GraphvizData {
@@ -409,7 +408,7 @@ impl GraphvizData {
         &mut self,
         bcb: BasicCoverageBlock,
         coverage_span: &CoverageSpan,
-        counter_kind: &CoverageKind,
+        counter_kind: &BcbCounter,
     ) {
         if let Some(bcb_to_coverage_spans_with_counters) =
             self.some_bcb_to_coverage_spans_with_counters.as_mut()
@@ -424,7 +423,7 @@ impl GraphvizData {
     pub fn get_bcb_coverage_spans_with_counters(
         &self,
         bcb: BasicCoverageBlock,
-    ) -> Option<&[(CoverageSpan, CoverageKind)]> {
+    ) -> Option<&[(CoverageSpan, BcbCounter)]> {
         if let Some(bcb_to_coverage_spans_with_counters) =
             self.some_bcb_to_coverage_spans_with_counters.as_ref()
         {
@@ -437,7 +436,7 @@ impl GraphvizData {
     pub fn add_bcb_dependency_counter(
         &mut self,
         bcb: BasicCoverageBlock,
-        counter_kind: &CoverageKind,
+        counter_kind: &BcbCounter,
     ) {
         if let Some(bcb_to_dependency_counters) = self.some_bcb_to_dependency_counters.as_mut() {
             bcb_to_dependency_counters
@@ -447,7 +446,7 @@ impl GraphvizData {
         }
     }
 
-    pub fn get_bcb_dependency_counters(&self, bcb: BasicCoverageBlock) -> Option<&[CoverageKind]> {
+    pub fn get_bcb_dependency_counters(&self, bcb: BasicCoverageBlock) -> Option<&[BcbCounter]> {
         if let Some(bcb_to_dependency_counters) = self.some_bcb_to_dependency_counters.as_ref() {
             bcb_to_dependency_counters.get(&bcb).map(Deref::deref)
         } else {
@@ -459,7 +458,7 @@ impl GraphvizData {
         &mut self,
         from_bcb: BasicCoverageBlock,
         to_bb: BasicBlock,
-        counter_kind: &CoverageKind,
+        counter_kind: &BcbCounter,
     ) {
         if let Some(edge_to_counter) = self.some_edge_to_counter.as_mut() {
             edge_to_counter
@@ -472,7 +471,7 @@ impl GraphvizData {
         &self,
         from_bcb: BasicCoverageBlock,
         to_bb: BasicBlock,
-    ) -> Option<&CoverageKind> {
+    ) -> Option<&BcbCounter> {
         if let Some(edge_to_counter) = self.some_edge_to_counter.as_ref() {
             edge_to_counter.get(&(from_bcb, to_bb))
         } else {
@@ -488,7 +487,7 @@ impl GraphvizData {
 pub(super) struct UsedExpressions {
     some_used_expression_operands: Option<FxHashMap<Operand, Vec<ExpressionId>>>,
     some_unused_expressions:
-        Option<Vec<(CoverageKind, Option<BasicCoverageBlock>, BasicCoverageBlock)>>,
+        Option<Vec<(BcbCounter, Option<BasicCoverageBlock>, BasicCoverageBlock)>>,
 }
 
 impl UsedExpressions {
@@ -506,16 +505,16 @@ impl UsedExpressions {
         self.some_used_expression_operands.is_some()
     }
 
-    pub fn add_expression_operands(&mut self, expression: &CoverageKind) {
+    pub fn add_expression_operands(&mut self, expression: &BcbCounter) {
         if let Some(used_expression_operands) = self.some_used_expression_operands.as_mut() {
-            if let CoverageKind::Expression { id, lhs, rhs, .. } = *expression {
+            if let BcbCounter::Expression { id, lhs, rhs, .. } = *expression {
                 used_expression_operands.entry(lhs).or_insert_with(Vec::new).push(id);
                 used_expression_operands.entry(rhs).or_insert_with(Vec::new).push(id);
             }
         }
     }
 
-    pub fn expression_is_used(&self, expression: &CoverageKind) -> bool {
+    pub fn expression_is_used(&self, expression: &BcbCounter) -> bool {
         if let Some(used_expression_operands) = self.some_used_expression_operands.as_ref() {
             used_expression_operands.contains_key(&expression.as_operand())
         } else {
@@ -525,7 +524,7 @@ impl UsedExpressions {
 
     pub fn add_unused_expression_if_not_found(
         &mut self,
-        expression: &CoverageKind,
+        expression: &BcbCounter,
         edge_from_bcb: Option<BasicCoverageBlock>,
         target_bcb: BasicCoverageBlock,
     ) {
@@ -540,11 +539,11 @@ impl UsedExpressions {
         }
     }
 
-    /// Return the list of unused counters (if any) as a tuple with the counter (`CoverageKind`),
+    /// Return the list of unused counters (if any) as a tuple with the counter (`BcbCounter`),
     /// optional `from_bcb` (if it was an edge counter), and `target_bcb`.
     pub fn get_unused_expressions(
         &self,
-    ) -> Vec<(CoverageKind, Option<BasicCoverageBlock>, BasicCoverageBlock)> {
+    ) -> Vec<(BcbCounter, Option<BasicCoverageBlock>, BasicCoverageBlock)> {
         if let Some(unused_expressions) = self.some_unused_expressions.as_ref() {
             unused_expressions.clone()
         } else {
@@ -560,7 +559,7 @@ impl UsedExpressions {
         bcb_counters_without_direct_coverage_spans: &[(
             Option<BasicCoverageBlock>,
             BasicCoverageBlock,
-            CoverageKind,
+            BcbCounter,
         )],
     ) {
         if self.is_enabled() {
@@ -662,7 +661,7 @@ pub(super) fn dump_coverage_graphviz<'tcx>(
     basic_coverage_blocks: &CoverageGraph,
     coverage_counters: &CoverageCounters,
     graphviz_data: &GraphvizData,
-    intermediate_expressions: &[CoverageKind],
+    intermediate_expressions: &[BcbCounter],
     debug_used_expressions: &UsedExpressions,
 ) {
     let debug_counters = &coverage_counters.debug_counters;
@@ -743,9 +742,9 @@ fn bcb_to_string_sections<'tcx>(
     coverage_counters: &CoverageCounters,
     bcb: BasicCoverageBlock,
     bcb_data: &BasicCoverageBlockData,
-    some_coverage_spans_with_counters: Option<&[(CoverageSpan, CoverageKind)]>,
-    some_dependency_counters: Option<&[CoverageKind]>,
-    some_intermediate_expressions: Option<&[CoverageKind]>,
+    some_coverage_spans_with_counters: Option<&[(CoverageSpan, BcbCounter)]>,
+    some_dependency_counters: Option<&[BcbCounter]>,
+    some_intermediate_expressions: Option<&[BcbCounter]>,
 ) -> Vec<String> {
     let debug_counters = &coverage_counters.debug_counters;