1 files changed, 54 insertions, 0 deletions
diff --git a/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h b/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
new file mode 100644
index 0000000..b9177f0
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
@@ -0,0 +1,54 @@
+//===-- llvm/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h ----*- 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_DBGVALUEHISTORYCALCULATOR_H_
+#define CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H_
+
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/SmallVector.h"
+
+namespace llvm {
+
+class MachineFunction;
+class MachineInstr;
+class MDNode;
+class TargetRegisterInfo;
+
+// For each user variable, keep a list of instruction ranges where this variable
+// is accessible. The variables are listed in order of appearance.
+class DbgValueHistoryMap {
+  // Each instruction range starts with a DBG_VALUE instruction, specifying the
+  // location of a variable, which is assumed to be valid until the end of the
+  // range. If end is not specified, location is valid until the start
+  // instruction of the next instruction range, or until the end of the
+  // function.
+  typedef std::pair<const MachineInstr *, const MachineInstr *> InstrRange;
+  typedef SmallVector<InstrRange, 4> InstrRanges;
+  typedef MapVector<const MDNode *, InstrRanges> InstrRangesMap;
+  InstrRangesMap VarInstrRanges;
+
+public:
+  void startInstrRange(const MDNode *Var, const MachineInstr &MI);
+  void endInstrRange(const MDNode *Var, const MachineInstr &MI);
+  // Returns register currently describing @Var. If @Var is currently
+  // unaccessible or is not described by a register, returns 0.
+  unsigned getRegisterForVar(const MDNode *Var) const;
+
+  bool empty() const { return VarInstrRanges.empty(); }
+  void clear() { VarInstrRanges.clear(); }
+  InstrRangesMap::const_iterator begin() const { return VarInstrRanges.begin(); }
+  InstrRangesMap::const_iterator end() const { return VarInstrRanges.end(); }
+};
+
+void calculateDbgValueHistory(const MachineFunction *MF,
+                              const TargetRegisterInfo *TRI,
+                              DbgValueHistoryMap &Result);
+}
+
+#endif