[llvm] [Coverage] Rework Decision/Expansion/Branch (PR #78969)

[Jessica Paquette via llvm-commits]

================
@@ -580,6 +583,72 @@ static unsigned getMaxBitmapSize(const CounterMappingContext &Ctx,
   return MaxBitmapID + (SizeInBits / CHAR_BIT);
 }
 
+struct DecisionRow {
+  const CounterMappingRegion *DecisionRegion;
+  LineColPair DecisionStartLoc;
+  LineColPair DecisionEndLoc;
+
+  SmallVector<const CounterMappingRegion *, 6> Branches;
+  DenseSet<CounterMappingRegion::MCDCConditionID> IDs;
+  SmallVector<const CounterMappingRegion *> Expansions;
+
+  DecisionRow(const CounterMappingRegion &Decision)
+      : DecisionRegion(&Decision), DecisionStartLoc(Decision.startLoc()),
+        DecisionEndLoc(Decision.endLoc()) {}
+
+  bool insert(const CounterMappingRegion &Branch) {
+    auto ID = Branch.MCDCParams.ID;
+    if (ID == 1)
+      Branches.insert(Branches.begin(), &Branch);
+    else
+      Branches.push_back(&Branch);
+    IDs.insert(ID);
+    return (Branches.size() == DecisionRegion->MCDCParams.NumConditions);
+  }
+
+  enum class UpdateResult {
+    NotFound = 0,
+    Updated,
+    Committed,
+  };
+
+  UpdateResult updateBranch(const CounterMappingRegion &Branch) {
+    if (IDs.contains(Branch.MCDCParams.ID))
+      return UpdateResult::NotFound;
+
+    if (Branch.FileID == DecisionRegion->FileID &&
+        Branch.startLoc() >= DecisionStartLoc &&
+        Branch.endLoc() <= DecisionEndLoc)
+      return (insert(Branch) ? UpdateResult::Committed : UpdateResult::Updated);
+
+    for (const auto *R : Expansions) {
+      if (Branch.FileID == R->ExpandedFileID)
+        return (insert(Branch) ? UpdateResult::Committed
+                               : UpdateResult::Updated);
+    }
+
+    return UpdateResult::NotFound;
+  }
+
+  bool updateExpansion(const CounterMappingRegion &Expansion) {
+    if (Expansion.FileID == DecisionRegion->FileID &&
+        Expansion.startLoc() >= DecisionStartLoc &&
+        Expansion.endLoc() <= DecisionEndLoc) {
+      Expansions.push_back(&Expansion);
+      return true;
+    }
+
+    for (const auto *R : Expansions) {
----------------
ornata wrote:

Looks like this could be written as `any_of` or `none_of`.

https://github.com/llvm/llvm-project/blob/3c246efd04210af56ab6ce960b98283ec5bc7c30/llvm/include/llvm/ADT/STLExtras.h#L1745

```
const auto FileID = Expansion.FileID;
if (none_of(Expansions, [&FileID](const CounterMappingRegion *R) {
      return R->ExpandedFileID == FileID;
    }))
  return false;
Expansions.push_back(*E);
return true;
```

https://github.com/llvm/llvm-project/pull/78969