DebugInfo: Split DebugLocEntry into its own file.

It seems big enough that it deserves its own file - but it is header
only, so there's no need for another cpp file, etc.

llvm-svn: 205360
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h b/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
new file mode 100644
index 0000000..e62897e
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
@@ -0,0 +1,112 @@
+//===-- llvm/CodeGen/DebugLocEntry.h - Entry in debug_loc list -*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H__
+#define CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H__
+#include "llvm/IR/Constants.h"
+#include "llvm/MC/MachineLocation.h"
+#include "llvm/MC/MCSymbol.h"
+
+namespace llvm {
+class DwarfCompileUnit;
+class MDNode;
+/// \brief 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;
+
+  // Type of entry that this represents.
+  enum EntryType { E_Location, E_Integer, E_ConstantFP, E_ConstantInt };
+  enum EntryType EntryKind;
+
+  union {
+    int64_t Int;
+    const ConstantFP *CFP;
+    const ConstantInt *CIP;
+  } Constants;
+
+  // The location in the machine frame.
+  MachineLocation Loc;
+
+  // The variable to which this location entry corresponds.
+  const MDNode *Variable;
+
+  // The compile unit to which this location entry is referenced by.
+  const DwarfCompileUnit *Unit;
+
+public:
+  DebugLocEntry() : Begin(0), End(0), Variable(0), Unit(0) {
+    Constants.Int = 0;
+  }
+  DebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L,
+                const MDNode *V, const DwarfCompileUnit *U)
+      : Begin(B), End(E), Loc(L), Variable(V), Unit(U) {
+    Constants.Int = 0;
+    EntryKind = E_Location;
+  }
+  DebugLocEntry(const MCSymbol *B, const MCSymbol *E, int64_t i,
+                const DwarfCompileUnit *U)
+      : Begin(B), End(E), Variable(0), Unit(U) {
+    Constants.Int = i;
+    EntryKind = E_Integer;
+  }
+  DebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantFP *FPtr,
+                const DwarfCompileUnit *U)
+      : Begin(B), End(E), Variable(0), Unit(U) {
+    Constants.CFP = FPtr;
+    EntryKind = E_ConstantFP;
+  }
+  DebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantInt *IPtr,
+                const DwarfCompileUnit *U)
+      : Begin(B), End(E), Variable(0), Unit(U) {
+    Constants.CIP = IPtr;
+    EntryKind = E_ConstantInt;
+  }
+
+  /// \brief Empty entries are also used as a trigger to emit temp label. Such
+  /// labels are referenced is used to find debug_loc offset for a given DIE.
+  bool isEmpty() const { return Begin == 0 && End == 0; }
+  bool Merge(const DebugLocEntry &Next) {
+    if (End != Next.Begin)
+      return false;
+
+    if (EntryKind != Next.EntryKind)
+      return false;
+
+    switch (EntryKind) {
+    case E_Location:
+      if (Loc != Next.Loc) return false;
+    case E_Integer:
+      if (Constants.Int != Next.Constants.Int) return false;
+    case E_ConstantFP:
+      if (Constants.CFP != Next.Constants.CFP) return false;
+    case E_ConstantInt:
+      if (Constants.CIP != Next.Constants.CIP) return false;
+    }
+
+    return true;
+  }
+  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 Constants.Int; }
+  const ConstantFP *getConstantFP() const { return Constants.CFP; }
+  const ConstantInt *getConstantInt() const { return Constants.CIP; }
+  const MDNode *getVariable() const { return Variable; }
+  const MCSymbol *getBeginSym() const { return Begin; }
+  const MCSymbol *getEndSym() const { return End; }
+  const DwarfCompileUnit *getCU() const { return Unit; }
+  MachineLocation getLoc() const { return Loc; }
+};
+
+}
+#endif