[DebugInfo] Move Value struct out of DebugLocEntry as DbgValueLoc (NFC)

[NikolaPrica]

Summary

Since the DebugLocEntry::Value is used as part of DwarfDebug and DebugLocEntry make it as the separate class.

lib/CodeGen/AsmPrinter/DebugLocEntry.h

 #include "llvm/IR/DebugInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MachineLocation.h"
 #include "llvm/Support/Debug.h"
 
 namespace llvm {
 class AsmPrinter;
 
-/// This struct describes location entries emitted in the .debug_loc
-/// section.
-class DebugLocEntry {
-  /// Begin and end symbols for the address range that this location is valid.
-  const MCSymbol *Begin;
-  const MCSymbol *End;
-
-public:
-  /// A single location or constant.
-  struct Value {
-    Value(const DIExpression *Expr, int64_t i)
-        : Expression(Expr), EntryKind(E_Integer) {
-      Constant.Int = i;
-    }
-    Value(const DIExpression *Expr, const ConstantFP *CFP)
-        : Expression(Expr), EntryKind(E_ConstantFP) {
-      Constant.CFP = CFP;
-    }
-    Value(const DIExpression *Expr, const ConstantInt *CIP)
-        : Expression(Expr), EntryKind(E_ConstantInt) {
-      Constant.CIP = CIP;
-    }
-    Value(const DIExpression *Expr, MachineLocation Loc)
-        : Expression(Expr), EntryKind(E_Location), Loc(Loc) {
-      assert(cast<DIExpression>(Expr)->isValid());
-    }
-
-    /// Any complex address location expression for this Value.
-    const DIExpression *Expression;
+class DbgValueLoc {
+  /// Any complex address location expression for this DbgValueLoc.
 
-    /// Type of entry that this represents.
-    enum EntryType { E_Location, E_Integer, E_ConstantFP, E_ConstantInt };
-    enum EntryType EntryKind;
 
-    /// Either a constant,
-    union {
-      int64_t Int;
-      const ConstantFP *CFP;
-      const ConstantInt *CIP;
-    } Constant;
 
-    // Or a location in the machine frame.
-    MachineLocation Loc;
+  /// Or a location in the machine frame.
 
-    bool isLocation() const { return EntryKind == E_Location; }
-    bool isInt() const { return EntryKind == E_Integer; }
-    bool isConstantFP() const { return EntryKind == E_ConstantFP; }
-    bool isConstantInt() const { return EntryKind == E_ConstantInt; }
-    int64_t getInt() const { return Constant.Int; }
-    const ConstantFP *getConstantFP() const { return Constant.CFP; }
-    const ConstantInt *getConstantInt() const { return Constant.CIP; }
-    MachineLocation getLoc() const { return Loc; }
-    bool isFragment() const { return getExpression()->isFragment(); }
-    const DIExpression *getExpression() const { return Expression; }
-    friend bool operator==(const Value &, const Value &);
-    friend bool operator<(const Value &, const Value &);
+public:
+  DbgValueLoc(const DIExpression *Expr, int64_t i)
+      : Expression(Expr), EntryKind(E_Integer) {
+    Constant.Int = i;
+  }
+  DbgValueLoc(const DIExpression *Expr, const ConstantFP *CFP)
+      : Expression(Expr), EntryKind(E_ConstantFP) {
+    Constant.CFP = CFP;
+  }
+  DbgValueLoc(const DIExpression *Expr, const ConstantInt *CIP)
+      : Expression(Expr), EntryKind(E_ConstantInt) {
+    Constant.CIP = CIP;
+  }
+  DbgValueLoc(const DIExpression *Expr, MachineLocation Loc)
+      : Expression(Expr), EntryKind(E_Location), Loc(Loc) {
+    assert(cast<DIExpression>(Expr)->isValid());
+  }
+
+  friend bool operator==(const DbgValueLoc &, const DbgValueLoc &);
+  friend bool operator<(const DbgValueLoc &, const DbgValueLoc &);
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-    LLVM_DUMP_METHOD void dump() const {
-      if (isLocation()) {
-        llvm::dbgs() << "Loc = { reg=" << Loc.getReg() << " ";
-        if (Loc.isIndirect())
-          llvm::dbgs() << "+0";
-        llvm::dbgs() << "} ";
-      }
-      else if (isConstantInt())
-        Constant.CIP->dump();
-      else if (isConstantFP())
-        Constant.CFP->dump();
-      if (Expression)
-        Expression->dump();
-    }
+    } else if (isConstantInt())
 #endif
-  };
 
-private:
+/// This struct describes location entries emitted in the .debug_loc
+/// section.
+class DebugLocEntry {
+  /// Begin and end symbols for the address range that this location is valid.
+  const MCSymbol *Begin;
+  const MCSymbol *End;
+
   /// A nonempty list of locations/constants belonging to this entry,
   /// sorted by offset.
-  SmallVector<Value, 1> Values;
+  SmallVector<DbgValueLoc, 1> Values;
 
 public:
   /// Create a location list entry for the range [\p Begin, \p End).
   ///
   /// \param Vals One or more values describing (parts of) the variable.
   DebugLocEntry(const MCSymbol *Begin, const MCSymbol *End,
-                ArrayRef<Value> Vals)
+                ArrayRef<DbgValueLoc> Vals)
       : Begin(Begin), End(End) {
     addValues(Vals);
   }
 
   /// Attempt to merge this DebugLocEntry with Next and return
   /// true if the merge was successful. Entries can be merged if they
   /// share the same Loc/Constant and if Next immediately follows this
   /// Entry.
   bool MergeRanges(const DebugLocEntry &Next) {
     // If this and Next are describing the same variable, merge them.
     if ((End == Next.Begin && Values == Next.Values)) {
       End = Next.End;
       return true;
     }
     return false;
   }
 
   const MCSymbol *getBeginSym() const { return Begin; }
   const MCSymbol *getEndSym() const { return End; }
-  ArrayRef<Value> getValues() const { return Values; }
-  void addValues(ArrayRef<DebugLocEntry::Value> Vals) {
+  ArrayRef<DbgValueLoc> getValues() const { return Values; }
+  void addValues(ArrayRef<DbgValueLoc> Vals) {
     Values.append(Vals.begin(), Vals.end());
     sortUniqueValues();
-    assert((Values.size() == 1 ||
-            all_of(Values,
-                   [](DebugLocEntry::Value V) { return V.isFragment(); })) &&
-           "must either have a single value or multiple pieces");
+    assert((Values.size() == 1 || all_of(Values, [](DbgValueLoc V) {
+              return V.isFragment();
+            })) && "must either have a single value or multiple pieces");
   }
 
   // Sort the pieces by offset.
   // Remove any duplicate entries by dropping all but the first.
   void sortUniqueValues() {
     llvm::sort(Values);
-    Values.erase(
-        std::unique(
-            Values.begin(), Values.end(), [](const Value &A, const Value &B) {
+    Values.erase(std::unique(Values.begin(), Values.end(),
+                             [](const DbgValueLoc &A, const DbgValueLoc &B) {
                                return A.getExpression() == B.getExpression();
                              }),
                  Values.end());
   }
 
   /// Lower this entry into a DWARF expression.
   void finalize(const AsmPrinter &AP,
                 DebugLocStream::ListBuilder &List,
                 const DIBasicType *BT,
                 DwarfCompileUnit &TheCU);
 };
 
-/// Compare two Values for equality.
-inline bool operator==(const DebugLocEntry::Value &A,
-                       const DebugLocEntry::Value &B) {
+/// Compare two DbgValueLocs for equality.
+inline bool operator==(const DbgValueLoc &A,
+                       const DbgValueLoc &B) {
   if (A.EntryKind != B.EntryKind)
     return false;
 
   if (A.Expression != B.Expression)
     return false;
 
   switch (A.EntryKind) {
-  case DebugLocEntry::Value::E_Location:
+  case DbgValueLoc::E_Location:
     return A.Loc == B.Loc;
-  case DebugLocEntry::Value::E_Integer:
+  case DbgValueLoc::E_Integer:
     return A.Constant.Int == B.Constant.Int;
-  case DebugLocEntry::Value::E_ConstantFP:
+  case DbgValueLoc::E_ConstantFP:
     return A.Constant.CFP == B.Constant.CFP;
-  case DebugLocEntry::Value::E_ConstantInt:
+  case DbgValueLoc::E_ConstantInt:
     return A.Constant.CIP == B.Constant.CIP;
   }
   llvm_unreachable("unhandled EntryKind");
 }
 
 /// Compare two fragments based on their offset.
-inline bool operator<(const DebugLocEntry::Value &A,
-                      const DebugLocEntry::Value &B) {
+inline bool operator<(const DbgValueLoc &A,
+                      const DbgValueLoc &B) {
   return A.getExpression()->getFragmentInfo()->OffsetInBits <
          B.getExpression()->getFragmentInfo()->OffsetInBits;
 }
 
 }
 
 #endif

lib/CodeGen/AsmPrinter/DwarfDebug.h

 /// location changes over time use \a DebugLocListIndex, while those with a
 /// single location use \a ValueLoc and (optionally) a single entry of \a Expr.
 ///
 /// Variables that have been optimized out use none of these fields.
 class DbgVariable : public DbgEntity {
   /// Offset in DebugLocs.
   unsigned DebugLocListIndex = ~0u;
   /// Single value location description.
-  std::unique_ptr<DebugLocEntry::Value> ValueLoc = nullptr;
+  std::unique_ptr<DbgValueLoc> ValueLoc = nullptr;
 
   struct FrameIndexExpr {
     int FI;
     const DIExpression *Expr;
   };
   mutable SmallVector<FrameIndexExpr, 1>
       FrameIndexExprs; /// Frame index + expression.
 
void initializeMMI(const DIExpression *E, int FI) {
 
     assert((!E || E->isValid()) && "Expected valid expression");
     assert(FI != std::numeric_limits<int>::max() && "Expected valid index");
 
     FrameIndexExprs.push_back({FI, E});
   }
 
   // Initialize variable's location.
-  void initializeDbgValue(DebugLocEntry::Value Value) {
+  void initializeDbgValue(DbgValueLoc Value) {
     assert(FrameIndexExprs.empty() && "Already initialized?");
     assert(!ValueLoc && "Already initialized?");
     assert(!Value.getExpression()->isFragment() && "Fragments not supported.");
 
-    ValueLoc = llvm::make_unique<DebugLocEntry::Value>(Value);
+    ValueLoc = llvm::make_unique<DbgValueLoc>(Value);
     if (auto *E = ValueLoc->getExpression())
       if (E->getNumElements())
         FrameIndexExprs.push_back({0, E});
   }
 
   /// Initialize from a DBG_VALUE instruction.
   void initializeDbgValue(const MachineInstr *DbgValue);
 
   // Accessors.
   const DILocalVariable *getVariable() const {
     return cast<DILocalVariable>(getEntity());
   }
 
   const DIExpression *getSingleExpression() const {
     assert(ValueLoc.get() && FrameIndexExprs.size() <= 1);
     return FrameIndexExprs.size() ? FrameIndexExprs[0].Expr : nullptr;
   }
 
   void setDebugLocListIndex(unsigned O) { DebugLocListIndex = O; }
   unsigned getDebugLocListIndex() const { return DebugLocListIndex; }
   StringRef getName() const { return getVariable()->getName(); }
-  const DebugLocEntry::Value *getValueLoc() const { return ValueLoc.get(); }
+  const DbgValueLoc *getValueLoc() const { return ValueLoc.get(); }
   /// Get the FI entries, sorted by fragment offset.
   ArrayRef<FrameIndexExpr> getFrameIndexExprs() const;
   bool hasFrameIndexExprs() const { return !FrameIndexExprs.empty(); }
   void addMMIEntry(const DbgVariable &V);
 
   // Translate tag to proper Dwarf tag.
   dwarf::Tag getTag() const {
     // FIXME: Why don't we just infer this tag and store it all along?

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
       if (getName() == DT->getName())
         return DT->getBaseType();
     }
   }
   return Ty;
 }
 
 /// Get .debug_loc entry for the instruction range starting at MI.
-static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
+static DbgValueLoc getDebugLocValue(const MachineInstr *MI) {
   const DIExpression *Expr = MI->getDebugExpression();
   assert(MI->getNumOperands() == 4);
   if (MI->getOperand(0).isReg()) {
     auto RegOp = MI->getOperand(0);
     auto Op1 = MI->getOperand(1);
     // If the second operand is an immediate, this is a
     // register-indirect address.
     assert((!Op1.isImm() || (Op1.getImm() == 0)) && "unexpected offset");
     MachineLocation MLoc(RegOp.getReg(), Op1.isImm());
-    return DebugLocEntry::Value(Expr, MLoc);
+    return DbgValueLoc(Expr, MLoc);
   }
   if (MI->getOperand(0).isImm())
-    return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
+    return DbgValueLoc(Expr, MI->getOperand(0).getImm());
   if (MI->getOperand(0).isFPImm())
-    return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
+    return DbgValueLoc(Expr, MI->getOperand(0).getFPImm());
   if (MI->getOperand(0).isCImm())
-    return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
+    return DbgValueLoc(Expr, MI->getOperand(0).getCImm());
 
   llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
 }
 
 void DbgVariable::initializeDbgValue(const MachineInstr *DbgValue) {
   assert(FrameIndexExprs.empty() && "Already initialized?");
   assert(!ValueLoc.get() && "Already initialized?");
 
   assert(getVariable() == DbgValue->getDebugVariable() && "Wrong variable");
   assert(getInlinedAt() == DbgValue->getDebugLoc()->getInlinedAt() &&
          "Wrong inlined-at");
 
-  ValueLoc = llvm::make_unique<DebugLocEntry::Value>(getDebugLocValue(DbgValue));
+  ValueLoc = llvm::make_unique<DbgValueLoc>(getDebugLocValue(DbgValue));
   if (auto *E = DbgValue->getDebugExpression())
     if (E->getNumElements())
       FrameIndexExprs.push_back({0, E});
 }
 
 ArrayRef<DbgVariable::FrameIndexExpr> DbgVariable::getFrameIndexExprs() const {
   if (FrameIndexExprs.size() == 1)
     return FrameIndexExprs;

 //
 // [0-1)    [(reg0, fragment 0, 32)]
 // [1-3)    [(reg0, fragment 0, 32), (reg1, fragment 32, 32)]
 // [3-4)    [(reg1, fragment 32, 32), (123, fragment 64, 32)]
 // [4-)     [(@g, fragment 0, 96)]
 bool DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
                                    const DbgValueHistoryMap::Entries &Entries) {
   using OpenRange =
-      std::pair<DbgValueHistoryMap::EntryIndex, DebugLocEntry::Value>;
+      std::pair<DbgValueHistoryMap::EntryIndex, DbgValueLoc>;
   SmallVector<OpenRange, 4> OpenRanges;
   bool isSafeForSingleLocation = true;
   const MachineInstr *StartDebugMI = nullptr;
   const MachineInstr *EndMI = nullptr;
 
   for (auto EB = Entries.begin(), EI = EB, EE = Entries.end(); EI != EE; ++EI) {
     const MachineInstr *Instr = EI->getInstr();
 
if (OpenRanges.empty())
       continue;
 
     // Omit entries with empty ranges as they do not have any effect in DWARF.
     if (StartLabel == EndLabel) {
       LLVM_DEBUG(dbgs() << "Omitting location list entry with empty range.\n");
       continue;
     }
 
-    SmallVector<DebugLocEntry::Value, 4> Values;
+    SmallVector<DbgValueLoc, 4> Values;
     for (auto &R : OpenRanges)
       Values.push_back(R.second);
     DebugLoc.emplace_back(StartLabel, EndLabel, Values);
 
     // Attempt to coalesce the ranges of two otherwise identical
     // DebugLocEntries.
     auto CurEntry = DebugLoc.rbegin();
     LLVM_DEBUG({
for (unsigned I = 0; I < 2; ++I) {
       }
       Offset = Op.getOperandEndOffset(I);
     }
     assert(Offset == Op.getEndOffset());
   }
 }
 
 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
-                              const DebugLocEntry::Value &Value,
+                              const DbgValueLoc &Value,
                               DwarfExpression &DwarfExpr) {
   auto *DIExpr = Value.getExpression();
   DIExpressionCursor ExprCursor(DIExpr);
   DwarfExpr.addFragmentOffset(DIExpr);
   // Regular entry.
   if (Value.isInt()) {
     if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
                BT->getEncoding() == dwarf::DW_ATE_signed_char))
void DebugLocEntry::finalize(const AsmPrinter &AP,
                              const DIBasicType *BT,
                              DwarfCompileUnit &TheCU) {
   assert(!Values.empty() &&
          "location list entries without values are redundant");
   assert(Begin != End && "unexpected location list entry with empty range");
   DebugLocStream::EntryBuilder Entry(List, Begin, End);
   BufferByteStreamer Streamer = Entry.getStreamer();
   DebugLocDwarfExpression DwarfExpr(AP.getDwarfVersion(), Streamer, TheCU);
-  const DebugLocEntry::Value &Value = Values[0];
+  const DbgValueLoc &Value = Values[0];
   if (Value.isFragment()) {
     // Emit all fragments that belong to the same variable and range.
-    assert(llvm::all_of(Values, [](DebugLocEntry::Value P) {
+    assert(llvm::all_of(Values, [](DbgValueLoc P) {
           return P.isFragment();
         }) && "all values are expected to be fragments");
     assert(std::is_sorted(Values.begin(), Values.end()) &&
            "fragments are expected to be sorted");
 
     for (auto Fragment : Values)
       emitDebugLocValue(AP, BT, Fragment, DwarfExpr);