[MC/DC] Refactor: Introduce MCDCTypes.h for coverage::mcdc (#81459)

They can be also used in `clang`.
Introduce the lightweight header instead of `CoverageMapping.h`.

This includes for now:
* `mcdc::ConditionID`
* `mcdc::Parameters`

Author: chapuni

clang/lib/CodeGen/CoverageMappingGen.cpp

@@ -95,9 +95,6 @@ void CoverageSourceInfo::updateNextTokLoc(SourceLocation Loc) {
 }
 
 namespace {
-using MCDCConditionID = CounterMappingRegion::MCDCConditionID;
-using MCDCParameters = CounterMappingRegion::MCDCParameters;
-
 /// A region of source code that can be mapped to a counter.
 class SourceMappingRegion {
   /// Primary Counter that is also used for Branch Regions for "True" branches.
@@ -107,7 +104,7 @@ class SourceMappingRegion {
   std::optional<Counter> FalseCount;
 
   /// Parameters used for Modified Condition/Decision Coverage
-  MCDCParameters MCDCParams;
+  mcdc::Parameters MCDCParams;
 
   /// The region's starting location.
   std::optional<SourceLocation> LocStart;
@@ -131,15 +128,15 @@ class SourceMappingRegion {
         SkippedRegion(false) {}
 
   SourceMappingRegion(Counter Count, std::optional<Counter> FalseCount,
-                      MCDCParameters MCDCParams,
+                      mcdc::Parameters MCDCParams,
                       std::optional<SourceLocation> LocStart,
                       std::optional<SourceLocation> LocEnd,
                       bool GapRegion = false)
       : Count(Count), FalseCount(FalseCount), MCDCParams(MCDCParams),
         LocStart(LocStart), LocEnd(LocEnd), GapRegion(GapRegion),
         SkippedRegion(false) {}
 
-  SourceMappingRegion(MCDCParameters MCDCParams,
+  SourceMappingRegion(mcdc::Parameters MCDCParams,
                       std::optional<SourceLocation> LocStart,
                       std::optional<SourceLocation> LocEnd)
       : MCDCParams(MCDCParams), LocStart(LocStart), LocEnd(LocEnd),
@@ -187,7 +184,7 @@ class SourceMappingRegion {
 
   bool isMCDCDecision() const { return MCDCParams.NumConditions != 0; }
 
-  const MCDCParameters &getMCDCParams() const { return MCDCParams; }
+  const mcdc::Parameters &getMCDCParams() const { return MCDCParams; }
 };
 
 /// Spelling locations for the start and end of a source region.
@@ -587,8 +584,8 @@ struct EmptyCoverageMappingBuilder : public CoverageMappingBuilder {
 struct MCDCCoverageBuilder {
 
   struct DecisionIDPair {
-    MCDCConditionID TrueID = 0;
-    MCDCConditionID FalseID = 0;
+    mcdc::ConditionID TrueID = 0;
+    mcdc::ConditionID FalseID = 0;
   };
 
   /// The AST walk recursively visits nested logical-AND or logical-OR binary
@@ -682,9 +679,9 @@ struct MCDCCoverageBuilder {
   CodeGenModule &CGM;
 
   llvm::SmallVector<DecisionIDPair> DecisionStack;
-  llvm::DenseMap<const Stmt *, MCDCConditionID> &CondIDs;
+  llvm::DenseMap<const Stmt *, mcdc::ConditionID> &CondIDs;
   llvm::DenseMap<const Stmt *, unsigned> &MCDCBitmapMap;
-  MCDCConditionID NextID = 1;
+  mcdc::ConditionID NextID = 1;
   bool NotMapped = false;
 
   /// Represent a sentinel value of [0,0] for the bottom of DecisionStack.
@@ -696,9 +693,10 @@ struct MCDCCoverageBuilder {
   }
 
 public:
-  MCDCCoverageBuilder(CodeGenModule &CGM,
-                      llvm::DenseMap<const Stmt *, MCDCConditionID> &CondIDMap,
-                      llvm::DenseMap<const Stmt *, unsigned> &MCDCBitmapMap)
+  MCDCCoverageBuilder(
+      CodeGenModule &CGM,
+      llvm::DenseMap<const Stmt *, mcdc::ConditionID> &CondIDMap,
+      llvm::DenseMap<const Stmt *, unsigned> &MCDCBitmapMap)
       : CGM(CGM), DecisionStack(1, DecisionStackSentinel), CondIDs(CondIDMap),
         MCDCBitmapMap(MCDCBitmapMap) {}
 
@@ -713,12 +711,12 @@ struct MCDCCoverageBuilder {
   bool isBuilding() const { return (NextID > 1); }
 
   /// Set the given condition's ID.
-  void setCondID(const Expr *Cond, MCDCConditionID ID) {
+  void setCondID(const Expr *Cond, mcdc::ConditionID ID) {
     CondIDs[CodeGenFunction::stripCond(Cond)] = ID;
   }
 
   /// Return the ID of a given condition.
-  MCDCConditionID getCondID(const Expr *Cond) const {
+  mcdc::ConditionID getCondID(const Expr *Cond) const {
     auto I = CondIDs.find(CodeGenFunction::stripCond(Cond));
     if (I == CondIDs.end())
       return 0;
@@ -755,7 +753,7 @@ struct MCDCCoverageBuilder {
       setCondID(E->getLHS(), NextID++);
 
     // Assign a ID+1 for the RHS.
-    MCDCConditionID RHSid = NextID++;
+    mcdc::ConditionID RHSid = NextID++;
     setCondID(E->getRHS(), RHSid);
 
     // Push the LHS decision IDs onto the DecisionStack.
@@ -865,8 +863,8 @@ struct CounterCoverageMappingBuilder
                     std::optional<SourceLocation> StartLoc = std::nullopt,
                     std::optional<SourceLocation> EndLoc = std::nullopt,
                     std::optional<Counter> FalseCount = std::nullopt,
-                    MCDCConditionID ID = 0, MCDCConditionID TrueID = 0,
-                    MCDCConditionID FalseID = 0) {
+                    mcdc::ConditionID ID = 0, mcdc::ConditionID TrueID = 0,
+                    mcdc::ConditionID FalseID = 0) {
 
     if (StartLoc && !FalseCount) {
       MostRecentLocation = *StartLoc;
@@ -886,7 +884,7 @@ struct CounterCoverageMappingBuilder
     if (EndLoc && EndLoc->isInvalid())
       EndLoc = std::nullopt;
     RegionStack.emplace_back(Count, FalseCount,
-                             MCDCParameters{0, 0, ID, TrueID, FalseID},
+                             mcdc::Parameters{0, 0, ID, TrueID, FalseID},
                              StartLoc, EndLoc);
 
     return RegionStack.size() - 1;
@@ -896,7 +894,7 @@ struct CounterCoverageMappingBuilder
                     std::optional<SourceLocation> StartLoc = std::nullopt,
                     std::optional<SourceLocation> EndLoc = std::nullopt) {
 
-    RegionStack.emplace_back(MCDCParameters{BitmapIdx, Conditions}, StartLoc,
+    RegionStack.emplace_back(mcdc::Parameters{BitmapIdx, Conditions}, StartLoc,
                              EndLoc);
 
     return RegionStack.size() - 1;
@@ -1042,9 +1040,9 @@ struct CounterCoverageMappingBuilder
     // function's SourceRegions) because it doesn't apply to any other source
     // code other than the Condition.
     if (CodeGenFunction::isInstrumentedCondition(C)) {
-      MCDCConditionID ID = MCDCBuilder.getCondID(C);
-      MCDCConditionID TrueID = IDPair.TrueID;
-      MCDCConditionID FalseID = IDPair.FalseID;
+      mcdc::ConditionID ID = MCDCBuilder.getCondID(C);
+      mcdc::ConditionID TrueID = IDPair.TrueID;
+      mcdc::ConditionID FalseID = IDPair.FalseID;
 
       // If a condition can fold to true or false, the corresponding branch
       // will be removed.  Create a region with both counters hard-coded to
@@ -1151,9 +1149,9 @@ struct CounterCoverageMappingBuilder
           if (I.isBranch())
             SourceRegions.emplace_back(
                 I.getCounter(), I.getFalseCounter(),
-                MCDCParameters{0, 0, I.getMCDCParams().ID,
-                               I.getMCDCParams().TrueID,
-                               I.getMCDCParams().FalseID},
+                mcdc::Parameters{0, 0, I.getMCDCParams().ID,
+                                 I.getMCDCParams().TrueID,
+                                 I.getMCDCParams().FalseID},
                 Loc, getEndOfFileOrMacro(Loc), I.isBranch());
           else
             SourceRegions.emplace_back(I.getCounter(), Loc,
@@ -1338,7 +1336,7 @@ struct CounterCoverageMappingBuilder
       CoverageMappingModuleGen &CVM,
       llvm::DenseMap<const Stmt *, unsigned> &CounterMap,
       llvm::DenseMap<const Stmt *, unsigned> &MCDCBitmapMap,
-      llvm::DenseMap<const Stmt *, MCDCConditionID> &CondIDMap,
+      llvm::DenseMap<const Stmt *, mcdc::ConditionID> &CondIDMap,
       SourceManager &SM, const LangOptions &LangOpts)
       : CoverageMappingBuilder(CVM, SM, LangOpts), CounterMap(CounterMap),
         MCDCBitmapMap(MCDCBitmapMap),

llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h

@@ -23,6 +23,7 @@
 #include "llvm/ADT/iterator.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Object/BuildID.h"
+#include "llvm/ProfileData/Coverage/MCDCTypes.h"
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/Support/Alignment.h"
 #include "llvm/Support/Compiler.h"
@@ -249,27 +250,14 @@ struct CounterMappingRegion {
     MCDCBranchRegion
   };
 
-  using MCDCConditionID = unsigned int;
-  struct MCDCParameters {
-    /// Byte Index of Bitmap Coverage Object for a Decision Region.
-    unsigned BitmapIdx = 0;
-
-    /// Number of Conditions used for a Decision Region.
-    unsigned NumConditions = 0;
-
-    /// IDs used to represent a branch region and other branch regions
-    /// evaluated based on True and False branches.
-    MCDCConditionID ID = 0, TrueID = 0, FalseID = 0;
-  };
-
   /// Primary Counter that is also used for Branch Regions (TrueCount).
   Counter Count;
 
   /// Secondary Counter used for Branch Regions (FalseCount).
   Counter FalseCount;
 
   /// Parameters used for Modified Condition/Decision Coverage
-  MCDCParameters MCDCParams;
+  mcdc::Parameters MCDCParams;
 
   unsigned FileID = 0;
   unsigned ExpandedFileID = 0;
@@ -285,7 +273,7 @@ struct CounterMappingRegion {
         ColumnEnd(ColumnEnd), Kind(Kind) {}
 
   CounterMappingRegion(Counter Count, Counter FalseCount,
-                       MCDCParameters MCDCParams, unsigned FileID,
+                       mcdc::Parameters MCDCParams, unsigned FileID,
                        unsigned ExpandedFileID, unsigned LineStart,
                        unsigned ColumnStart, unsigned LineEnd,
                        unsigned ColumnEnd, RegionKind Kind)
@@ -294,7 +282,7 @@ struct CounterMappingRegion {
         ColumnStart(ColumnStart), LineEnd(LineEnd), ColumnEnd(ColumnEnd),
         Kind(Kind) {}
 
-  CounterMappingRegion(MCDCParameters MCDCParams, unsigned FileID,
+  CounterMappingRegion(mcdc::Parameters MCDCParams, unsigned FileID,
                        unsigned LineStart, unsigned ColumnStart,
                        unsigned LineEnd, unsigned ColumnEnd, RegionKind Kind)
       : MCDCParams(MCDCParams), FileID(FileID), LineStart(LineStart),
@@ -334,23 +322,24 @@ struct CounterMappingRegion {
   makeBranchRegion(Counter Count, Counter FalseCount, unsigned FileID,
                    unsigned LineStart, unsigned ColumnStart, unsigned LineEnd,
                    unsigned ColumnEnd) {
-    return CounterMappingRegion(Count, FalseCount, MCDCParameters(), FileID, 0,
-                                LineStart, ColumnStart, LineEnd, ColumnEnd,
+    return CounterMappingRegion(Count, FalseCount, mcdc::Parameters(), FileID,
+                                0, LineStart, ColumnStart, LineEnd, ColumnEnd,
                                 BranchRegion);
   }
 
   static CounterMappingRegion
-  makeBranchRegion(Counter Count, Counter FalseCount, MCDCParameters MCDCParams,
-                   unsigned FileID, unsigned LineStart, unsigned ColumnStart,
-                   unsigned LineEnd, unsigned ColumnEnd) {
+  makeBranchRegion(Counter Count, Counter FalseCount,
+                   mcdc::Parameters MCDCParams, unsigned FileID,
+                   unsigned LineStart, unsigned ColumnStart, unsigned LineEnd,
+                   unsigned ColumnEnd) {
     return CounterMappingRegion(Count, FalseCount, MCDCParams, FileID, 0,
                                 LineStart, ColumnStart, LineEnd, ColumnEnd,
                                 MCDCParams.ID == 0 ? BranchRegion
                                                    : MCDCBranchRegion);
   }
 
   static CounterMappingRegion
-  makeDecisionRegion(MCDCParameters MCDCParams, unsigned FileID,
+  makeDecisionRegion(mcdc::Parameters MCDCParams, unsigned FileID,
                      unsigned LineStart, unsigned ColumnStart, unsigned LineEnd,
                      unsigned ColumnEnd) {
     return CounterMappingRegion(MCDCParams, FileID, LineStart, ColumnStart,

llvm/include/llvm/ProfileData/Coverage/MCDCTypes.h

@@ -0,0 +1,36 @@
+//===- MCDCTypes.h - Types related to MC/DC Coverage ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Types related to MC/DC Coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PROFILEDATA_COVERAGE_MCDCTYPES_H
+#define LLVM_PROFILEDATA_COVERAGE_MCDCTYPES_H
+
+namespace llvm::coverage::mcdc {
+
+/// The ID for MCDCBranch.
+using ConditionID = unsigned int;
+
+/// MC/DC-specifig parameters
+struct Parameters {
+  /// Byte Index of Bitmap Coverage Object for a Decision Region.
+  unsigned BitmapIdx = 0;
+
+  /// Number of Conditions used for a Decision Region.
+  unsigned NumConditions = 0;
+
+  /// IDs used to represent a branch region and other branch regions
+  /// evaluated based on True and False branches.
+  ConditionID ID = 0, TrueID = 0, FalseID = 0;
+};
+
+} // namespace llvm::coverage::mcdc
+
+#endif // LLVM_PROFILEDATA_COVERAGE_MCDCTYPES_H

llvm/lib/ProfileData/Coverage/CoverageMapping.cpp

@@ -524,7 +524,7 @@ class MCDCDecisionRecorder {
 
     /// IDs that are stored in MCDCBranches
     /// Complete when all IDs (1 to NumConditions) are met.
-    DenseSet<CounterMappingRegion::MCDCConditionID> ConditionIDs;
+    DenseSet<mcdc::ConditionID> ConditionIDs;
 
     /// Set of IDs of Expansion(s) that are relevant to DecisionRegion
     /// and its children (via expansions).

llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp

@@ -371,10 +371,9 @@ Error RawCoverageMappingReader::readMappingRegionsSubArray(
 
     auto CMR = CounterMappingRegion(
         C, C2,
-        CounterMappingRegion::MCDCParameters{
-            static_cast<unsigned>(BIDX), static_cast<unsigned>(NC),
-            static_cast<unsigned>(ID), static_cast<unsigned>(TID),
-            static_cast<unsigned>(FID)},
+        mcdc::Parameters{static_cast<unsigned>(BIDX), static_cast<unsigned>(NC),
+                         static_cast<unsigned>(ID), static_cast<unsigned>(TID),
+                         static_cast<unsigned>(FID)},
         InferredFileID, ExpandedFileID, LineStart, ColumnStart,
         LineStart + NumLines, ColumnEnd, Kind);
     if (CMR.startLoc() > CMR.endLoc())

llvm/unittests/ProfileData/CoverageMappingTest.cpp

@@ -197,8 +197,7 @@ struct CoverageMappingTest : ::testing::TestWithParam<std::tuple<bool, bool>> {
     auto &Regions = InputFunctions.back().Regions;
     unsigned FileID = getFileIndexForFunction(File);
     Regions.push_back(CounterMappingRegion::makeDecisionRegion(
-        CounterMappingRegion::MCDCParameters{Mask, NC}, FileID, LS, CS, LE,
-        CE));
+        mcdc::Parameters{Mask, NC}, FileID, LS, CS, LE, CE));
   }
 
   void addMCDCBranchCMR(Counter C1, Counter C2, unsigned ID, unsigned TrueID,
@@ -207,8 +206,8 @@ struct CoverageMappingTest : ::testing::TestWithParam<std::tuple<bool, bool>> {
     auto &Regions = InputFunctions.back().Regions;
     unsigned FileID = getFileIndexForFunction(File);
     Regions.push_back(CounterMappingRegion::makeBranchRegion(
-        C1, C2, CounterMappingRegion::MCDCParameters{0, 0, ID, TrueID, FalseID},
-        FileID, LS, CS, LE, CE));
+        C1, C2, mcdc::Parameters{0, 0, ID, TrueID, FalseID}, FileID, LS, CS, LE,
+        CE));
   }
 
   void addExpansionCMR(StringRef File, StringRef ExpandedFile, unsigned LS,