681 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			681 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- DWARFDebugFrame.h - Parsing of .debug_frame -------------*- C++ -*-===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
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| #include "llvm/ADT/ArrayRef.h"
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| #include "llvm/ADT/DenseMap.h"
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| #include "llvm/ADT/Optional.h"
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| #include "llvm/ADT/SmallString.h"
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| #include "llvm/ADT/StringExtras.h"
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| #include "llvm/Support/Casting.h"
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| #include "llvm/Support/DataTypes.h"
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| #include "llvm/Support/Dwarf.h"
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| #include "llvm/Support/ErrorHandling.h"
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| #include "llvm/Support/Format.h"
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| #include "llvm/Support/raw_ostream.h"
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| #include <string>
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| #include <utility>
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| #include <vector>
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| 
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| using namespace llvm;
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| using namespace dwarf;
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| 
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| 
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| /// \brief Abstract frame entry defining the common interface concrete
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| /// entries implement.
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| class llvm::FrameEntry {
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| public:
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|   enum FrameKind {FK_CIE, FK_FDE};
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|   FrameEntry(FrameKind K, uint64_t Offset, uint64_t Length)
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|       : Kind(K), Offset(Offset), Length(Length) {}
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| 
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|   virtual ~FrameEntry() {
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|   }
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| 
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|   FrameKind getKind() const { return Kind; }
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|   virtual uint64_t getOffset() const { return Offset; }
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| 
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|   /// \brief Parse and store a sequence of CFI instructions from Data,
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|   /// starting at *Offset and ending at EndOffset. If everything
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|   /// goes well, *Offset should be equal to EndOffset when this method
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|   /// returns. Otherwise, an error occurred.
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|   virtual void parseInstructions(DataExtractor Data, uint32_t *Offset,
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|                                  uint32_t EndOffset);
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| 
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|   /// \brief Dump the entry header to the given output stream.
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|   virtual void dumpHeader(raw_ostream &OS) const = 0;
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| 
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|   /// \brief Dump the entry's instructions to the given output stream.
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|   virtual void dumpInstructions(raw_ostream &OS) const;
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| 
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| protected:
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|   const FrameKind Kind;
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| 
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|   /// \brief Offset of this entry in the section.
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|   uint64_t Offset;
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| 
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|   /// \brief Entry length as specified in DWARF.
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|   uint64_t Length;
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| 
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|   /// An entry may contain CFI instructions. An instruction consists of an
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|   /// opcode and an optional sequence of operands.
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|   typedef std::vector<uint64_t> Operands;
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|   struct Instruction {
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|     Instruction(uint8_t Opcode)
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|       : Opcode(Opcode)
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|     {}
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| 
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|     uint8_t Opcode;
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|     Operands Ops;
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|   };
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| 
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|   std::vector<Instruction> Instructions;
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| 
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|   /// Convenience methods to add a new instruction with the given opcode and
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|   /// operands to the Instructions vector.
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|   void addInstruction(uint8_t Opcode) {
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|     Instructions.push_back(Instruction(Opcode));
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|   }
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| 
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|   void addInstruction(uint8_t Opcode, uint64_t Operand1) {
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|     Instructions.push_back(Instruction(Opcode));
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|     Instructions.back().Ops.push_back(Operand1);
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|   }
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| 
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|   void addInstruction(uint8_t Opcode, uint64_t Operand1, uint64_t Operand2) {
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|     Instructions.push_back(Instruction(Opcode));
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|     Instructions.back().Ops.push_back(Operand1);
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|     Instructions.back().Ops.push_back(Operand2);
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|   }
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| };
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| 
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| 
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| // See DWARF standard v3, section 7.23
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| const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0;
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| const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f;
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| 
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| void FrameEntry::parseInstructions(DataExtractor Data, uint32_t *Offset,
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|                                    uint32_t EndOffset) {
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|   while (*Offset < EndOffset) {
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|     uint8_t Opcode = Data.getU8(Offset);
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|     // Some instructions have a primary opcode encoded in the top bits.
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|     uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK;
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| 
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|     if (Primary) {
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|       // If it's a primary opcode, the first operand is encoded in the bottom
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|       // bits of the opcode itself.
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|       uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK;
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|       switch (Primary) {
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|         default: llvm_unreachable("Impossible primary CFI opcode");
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|         case DW_CFA_advance_loc:
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|         case DW_CFA_restore:
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|           addInstruction(Primary, Op1);
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|           break;
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|         case DW_CFA_offset:
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|           addInstruction(Primary, Op1, Data.getULEB128(Offset));
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|           break;
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|       }
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|     } else {
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|       // Extended opcode - its value is Opcode itself.
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|       switch (Opcode) {
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|         default: llvm_unreachable("Invalid extended CFI opcode");
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|         case DW_CFA_nop:
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|         case DW_CFA_remember_state:
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|         case DW_CFA_restore_state:
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|         case DW_CFA_GNU_window_save:
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|           // No operands
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|           addInstruction(Opcode);
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|           break;
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|         case DW_CFA_set_loc:
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|           // Operands: Address
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|           addInstruction(Opcode, Data.getAddress(Offset));
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|           break;
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|         case DW_CFA_advance_loc1:
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|           // Operands: 1-byte delta
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|           addInstruction(Opcode, Data.getU8(Offset));
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|           break;
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|         case DW_CFA_advance_loc2:
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|           // Operands: 2-byte delta
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|           addInstruction(Opcode, Data.getU16(Offset));
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|           break;
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|         case DW_CFA_advance_loc4:
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|           // Operands: 4-byte delta
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|           addInstruction(Opcode, Data.getU32(Offset));
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|           break;
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|         case DW_CFA_restore_extended:
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|         case DW_CFA_undefined:
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|         case DW_CFA_same_value:
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|         case DW_CFA_def_cfa_register:
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|         case DW_CFA_def_cfa_offset:
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|           // Operands: ULEB128
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|           addInstruction(Opcode, Data.getULEB128(Offset));
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|           break;
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|         case DW_CFA_def_cfa_offset_sf:
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|           // Operands: SLEB128
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|           addInstruction(Opcode, Data.getSLEB128(Offset));
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|           break;
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|         case DW_CFA_offset_extended:
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|         case DW_CFA_register:
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|         case DW_CFA_def_cfa:
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|         case DW_CFA_val_offset: {
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|           // Operands: ULEB128, ULEB128
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|           // Note: We can not embed getULEB128 directly into function
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|           // argument list. getULEB128 changes Offset and order of evaluation
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|           // for arguments is unspecified.
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|           auto op1 = Data.getULEB128(Offset);
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|           auto op2 = Data.getULEB128(Offset);
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|           addInstruction(Opcode, op1, op2);
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|           break;
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|         }
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|         case DW_CFA_offset_extended_sf:
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|         case DW_CFA_def_cfa_sf:
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|         case DW_CFA_val_offset_sf: {
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|           // Operands: ULEB128, SLEB128
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|           // Note: see comment for the previous case
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|           auto op1 = Data.getULEB128(Offset);
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|           auto op2 = (uint64_t)Data.getSLEB128(Offset);
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|           addInstruction(Opcode, op1, op2);
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|           break;
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|         }
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|         case DW_CFA_def_cfa_expression:
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|         case DW_CFA_expression:
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|         case DW_CFA_val_expression:
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|           // TODO: implement this
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|           report_fatal_error("Values with expressions not implemented yet!");
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|       }
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|     }
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|   }
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| }
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| 
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| namespace {
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| /// \brief DWARF Common Information Entry (CIE)
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| class CIE : public FrameEntry {
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| public:
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|   // CIEs (and FDEs) are simply container classes, so the only sensible way to
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|   // create them is by providing the full parsed contents in the constructor.
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|   CIE(uint64_t Offset, uint64_t Length, uint8_t Version,
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|       SmallString<8> Augmentation, uint8_t AddressSize,
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|       uint8_t SegmentDescriptorSize, uint64_t CodeAlignmentFactor,
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|       int64_t DataAlignmentFactor, uint64_t ReturnAddressRegister,
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|       SmallString<8> AugmentationData, uint32_t FDEPointerEncoding,
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|       uint32_t LSDAPointerEncoding)
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|       : FrameEntry(FK_CIE, Offset, Length), Version(Version),
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|         Augmentation(std::move(Augmentation)), AddressSize(AddressSize),
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|         SegmentDescriptorSize(SegmentDescriptorSize),
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|         CodeAlignmentFactor(CodeAlignmentFactor),
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|         DataAlignmentFactor(DataAlignmentFactor),
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|         ReturnAddressRegister(ReturnAddressRegister),
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|         AugmentationData(std::move(AugmentationData)),
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|         FDEPointerEncoding(FDEPointerEncoding),
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|         LSDAPointerEncoding(LSDAPointerEncoding) {}
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| 
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|   ~CIE() override {}
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| 
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|   StringRef getAugmentationString() const { return Augmentation; }
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|   uint64_t getCodeAlignmentFactor() const { return CodeAlignmentFactor; }
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|   int64_t getDataAlignmentFactor() const { return DataAlignmentFactor; }
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|   uint32_t getFDEPointerEncoding() const {
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|     return FDEPointerEncoding;
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|   }
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|   uint32_t getLSDAPointerEncoding() const {
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|     return LSDAPointerEncoding;
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|   }
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| 
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|   void dumpHeader(raw_ostream &OS) const override {
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|     OS << format("%08x %08x %08x CIE",
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|                  (uint32_t)Offset, (uint32_t)Length, DW_CIE_ID)
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|        << "\n";
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|     OS << format("  Version:               %d\n", Version);
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|     OS << "  Augmentation:          \"" << Augmentation << "\"\n";
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|     if (Version >= 4) {
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|       OS << format("  Address size:          %u\n",
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|                    (uint32_t)AddressSize);
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|       OS << format("  Segment desc size:     %u\n",
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|                    (uint32_t)SegmentDescriptorSize);
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|     }
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|     OS << format("  Code alignment factor: %u\n",
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|                  (uint32_t)CodeAlignmentFactor);
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|     OS << format("  Data alignment factor: %d\n",
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|                  (int32_t)DataAlignmentFactor);
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|     OS << format("  Return address column: %d\n",
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|                  (int32_t)ReturnAddressRegister);
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|     if (!AugmentationData.empty()) {
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|       OS << "  Augmentation data:    ";
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|       for (uint8_t Byte : AugmentationData)
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|         OS << ' ' << hexdigit(Byte >> 4) << hexdigit(Byte & 0xf);
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|       OS << "\n";
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|     }
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|     OS << "\n";
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|   }
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| 
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|   static bool classof(const FrameEntry *FE) {
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|     return FE->getKind() == FK_CIE;
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|   }
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| 
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| private:
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|   /// The following fields are defined in section 6.4.1 of the DWARF standard v4
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|   uint8_t Version;
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|   SmallString<8> Augmentation;
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|   uint8_t AddressSize;
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|   uint8_t SegmentDescriptorSize;
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|   uint64_t CodeAlignmentFactor;
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|   int64_t DataAlignmentFactor;
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|   uint64_t ReturnAddressRegister;
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| 
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|   // The following are used when the CIE represents an EH frame entry.
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|   SmallString<8> AugmentationData;
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|   uint32_t FDEPointerEncoding;
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|   uint32_t LSDAPointerEncoding;
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| };
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| 
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| 
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| /// \brief DWARF Frame Description Entry (FDE)
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| class FDE : public FrameEntry {
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| public:
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|   // Each FDE has a CIE it's "linked to". Our FDE contains is constructed with
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|   // an offset to the CIE (provided by parsing the FDE header). The CIE itself
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|   // is obtained lazily once it's actually required.
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|   FDE(uint64_t Offset, uint64_t Length, int64_t LinkedCIEOffset,
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|       uint64_t InitialLocation, uint64_t AddressRange,
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|       CIE *Cie)
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|       : FrameEntry(FK_FDE, Offset, Length), LinkedCIEOffset(LinkedCIEOffset),
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|         InitialLocation(InitialLocation), AddressRange(AddressRange),
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|         LinkedCIE(Cie) {}
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| 
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|   ~FDE() override {}
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| 
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|   CIE *getLinkedCIE() const { return LinkedCIE; }
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| 
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|   void dumpHeader(raw_ostream &OS) const override {
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|     OS << format("%08x %08x %08x FDE ",
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|                  (uint32_t)Offset, (uint32_t)Length, (int32_t)LinkedCIEOffset);
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|     OS << format("cie=%08x pc=%08x...%08x\n",
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|                  (int32_t)LinkedCIEOffset,
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|                  (uint32_t)InitialLocation,
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|                  (uint32_t)InitialLocation + (uint32_t)AddressRange);
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|   }
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| 
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|   static bool classof(const FrameEntry *FE) {
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|     return FE->getKind() == FK_FDE;
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|   }
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| 
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| private:
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|   /// The following fields are defined in section 6.4.1 of the DWARF standard v3
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|   uint64_t LinkedCIEOffset;
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|   uint64_t InitialLocation;
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|   uint64_t AddressRange;
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|   CIE *LinkedCIE;
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| };
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| 
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| /// \brief Types of operands to CF instructions.
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| enum OperandType {
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|   OT_Unset,
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|   OT_None,
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|   OT_Address,
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|   OT_Offset,
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|   OT_FactoredCodeOffset,
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|   OT_SignedFactDataOffset,
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|   OT_UnsignedFactDataOffset,
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|   OT_Register,
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|   OT_Expression
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| };
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| 
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| } // end anonymous namespace
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| 
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| /// \brief Initialize the array describing the types of operands.
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| static ArrayRef<OperandType[2]> getOperandTypes() {
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|   static OperandType OpTypes[DW_CFA_restore+1][2];
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| 
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| #define DECLARE_OP2(OP, OPTYPE0, OPTYPE1)       \
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|   do {                                          \
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|     OpTypes[OP][0] = OPTYPE0;                   \
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|     OpTypes[OP][1] = OPTYPE1;                   \
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|   } while (0)
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| #define DECLARE_OP1(OP, OPTYPE0) DECLARE_OP2(OP, OPTYPE0, OT_None)
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| #define DECLARE_OP0(OP) DECLARE_OP1(OP, OT_None)
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| 
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|   DECLARE_OP1(DW_CFA_set_loc, OT_Address);
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|   DECLARE_OP1(DW_CFA_advance_loc, OT_FactoredCodeOffset);
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|   DECLARE_OP1(DW_CFA_advance_loc1, OT_FactoredCodeOffset);
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|   DECLARE_OP1(DW_CFA_advance_loc2, OT_FactoredCodeOffset);
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|   DECLARE_OP1(DW_CFA_advance_loc4, OT_FactoredCodeOffset);
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|   DECLARE_OP1(DW_CFA_MIPS_advance_loc8, OT_FactoredCodeOffset);
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|   DECLARE_OP2(DW_CFA_def_cfa, OT_Register, OT_Offset);
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|   DECLARE_OP2(DW_CFA_def_cfa_sf, OT_Register, OT_SignedFactDataOffset);
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|   DECLARE_OP1(DW_CFA_def_cfa_register, OT_Register);
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|   DECLARE_OP1(DW_CFA_def_cfa_offset, OT_Offset);
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|   DECLARE_OP1(DW_CFA_def_cfa_offset_sf, OT_SignedFactDataOffset);
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|   DECLARE_OP1(DW_CFA_def_cfa_expression, OT_Expression);
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|   DECLARE_OP1(DW_CFA_undefined, OT_Register);
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|   DECLARE_OP1(DW_CFA_same_value, OT_Register);
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|   DECLARE_OP2(DW_CFA_offset, OT_Register, OT_UnsignedFactDataOffset);
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|   DECLARE_OP2(DW_CFA_offset_extended, OT_Register, OT_UnsignedFactDataOffset);
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|   DECLARE_OP2(DW_CFA_offset_extended_sf, OT_Register, OT_SignedFactDataOffset);
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|   DECLARE_OP2(DW_CFA_val_offset, OT_Register, OT_UnsignedFactDataOffset);
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|   DECLARE_OP2(DW_CFA_val_offset_sf, OT_Register, OT_SignedFactDataOffset);
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|   DECLARE_OP2(DW_CFA_register, OT_Register, OT_Register);
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|   DECLARE_OP2(DW_CFA_expression, OT_Register, OT_Expression);
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|   DECLARE_OP2(DW_CFA_val_expression, OT_Register, OT_Expression);
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|   DECLARE_OP1(DW_CFA_restore, OT_Register);
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|   DECLARE_OP1(DW_CFA_restore_extended, OT_Register);
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|   DECLARE_OP0(DW_CFA_remember_state);
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|   DECLARE_OP0(DW_CFA_restore_state);
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|   DECLARE_OP0(DW_CFA_GNU_window_save);
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|   DECLARE_OP1(DW_CFA_GNU_args_size, OT_Offset);
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|   DECLARE_OP0(DW_CFA_nop);
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| 
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| #undef DECLARE_OP0
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| #undef DECLARE_OP1
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| #undef DECLARE_OP2
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|   return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1);
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| }
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| 
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| static ArrayRef<OperandType[2]> OpTypes = getOperandTypes();
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| 
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| /// \brief Print \p Opcode's operand number \p OperandIdx which has
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| /// value \p Operand.
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| static void printOperand(raw_ostream &OS, uint8_t Opcode, unsigned OperandIdx,
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|                          uint64_t Operand, uint64_t CodeAlignmentFactor,
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|                          int64_t DataAlignmentFactor) {
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|   assert(OperandIdx < 2);
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|   OperandType Type = OpTypes[Opcode][OperandIdx];
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| 
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|   switch (Type) {
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|   case OT_Unset:
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|     OS << " Unsupported " << (OperandIdx ? "second" : "first") << " operand to";
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|     if (const char *OpcodeName = CallFrameString(Opcode))
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|       OS << " " << OpcodeName;
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|     else
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|       OS << format(" Opcode %x",  Opcode);
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|     break;
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|   case OT_None:
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|     break;
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|   case OT_Address:
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|     OS << format(" %" PRIx64, Operand);
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|     break;
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|   case OT_Offset:
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|     // The offsets are all encoded in a unsigned form, but in practice
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|     // consumers use them signed. It's most certainly legacy due to
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|     // the lack of signed variants in the first Dwarf standards.
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|     OS << format(" %+" PRId64, int64_t(Operand));
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|     break;
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|   case OT_FactoredCodeOffset: // Always Unsigned
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|     if (CodeAlignmentFactor)
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|       OS << format(" %" PRId64, Operand * CodeAlignmentFactor);
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|     else
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|       OS << format(" %" PRId64 "*code_alignment_factor" , Operand);
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|     break;
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|   case OT_SignedFactDataOffset:
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|     if (DataAlignmentFactor)
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|       OS << format(" %" PRId64, int64_t(Operand) * DataAlignmentFactor);
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|     else
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|       OS << format(" %" PRId64 "*data_alignment_factor" , int64_t(Operand));
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|     break;
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|   case OT_UnsignedFactDataOffset:
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|     if (DataAlignmentFactor)
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|       OS << format(" %" PRId64, Operand * DataAlignmentFactor);
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|     else
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|       OS << format(" %" PRId64 "*data_alignment_factor" , Operand);
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|     break;
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|   case OT_Register:
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|     OS << format(" reg%" PRId64, Operand);
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|     break;
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|   case OT_Expression:
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|     OS << " expression";
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|     break;
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|   }
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| }
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| 
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| void FrameEntry::dumpInstructions(raw_ostream &OS) const {
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|   uint64_t CodeAlignmentFactor = 0;
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|   int64_t DataAlignmentFactor = 0;
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|   const CIE *Cie = dyn_cast<CIE>(this);
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| 
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|   if (!Cie)
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|     Cie = cast<FDE>(this)->getLinkedCIE();
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|   if (Cie) {
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|     CodeAlignmentFactor = Cie->getCodeAlignmentFactor();
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|     DataAlignmentFactor = Cie->getDataAlignmentFactor();
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|   }
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| 
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|   for (const auto &Instr : Instructions) {
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|     uint8_t Opcode = Instr.Opcode;
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|     if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK)
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|       Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK;
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|     OS << "  " << CallFrameString(Opcode) << ":";
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|     for (unsigned i = 0; i < Instr.Ops.size(); ++i)
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|       printOperand(OS, Opcode, i, Instr.Ops[i], CodeAlignmentFactor,
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|                    DataAlignmentFactor);
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|     OS << '\n';
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|   }
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| }
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| 
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| DWARFDebugFrame::DWARFDebugFrame(bool IsEH) : IsEH(IsEH) {
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| }
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| 
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| DWARFDebugFrame::~DWARFDebugFrame() {
 | |
| }
 | |
| 
 | |
| static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data,
 | |
|                                               uint32_t Offset, int Length) {
 | |
|   errs() << "DUMP: ";
 | |
|   for (int i = 0; i < Length; ++i) {
 | |
|     uint8_t c = Data.getU8(&Offset);
 | |
|     errs().write_hex(c); errs() << " ";
 | |
|   }
 | |
|   errs() << "\n";
 | |
| }
 | |
| 
 | |
| static unsigned getSizeForEncoding(const DataExtractor &Data,
 | |
|                                    unsigned symbolEncoding) {
 | |
|   unsigned format = symbolEncoding & 0x0f;
 | |
|   switch (format) {
 | |
|     default: llvm_unreachable("Unknown Encoding");
 | |
|     case dwarf::DW_EH_PE_absptr:
 | |
|     case dwarf::DW_EH_PE_signed:
 | |
|       return Data.getAddressSize();
 | |
|     case dwarf::DW_EH_PE_udata2:
 | |
|     case dwarf::DW_EH_PE_sdata2:
 | |
|       return 2;
 | |
|     case dwarf::DW_EH_PE_udata4:
 | |
|     case dwarf::DW_EH_PE_sdata4:
 | |
|       return 4;
 | |
|     case dwarf::DW_EH_PE_udata8:
 | |
|     case dwarf::DW_EH_PE_sdata8:
 | |
|       return 8;
 | |
|   }
 | |
| }
 | |
| 
 | |
| static uint64_t readPointer(const DataExtractor &Data, uint32_t &Offset,
 | |
|                             unsigned Encoding) {
 | |
|   switch (getSizeForEncoding(Data, Encoding)) {
 | |
|     case 2:
 | |
|       return Data.getU16(&Offset);
 | |
|     case 4:
 | |
|       return Data.getU32(&Offset);
 | |
|     case 8:
 | |
|       return Data.getU64(&Offset);
 | |
|     default:
 | |
|       llvm_unreachable("Illegal data size");
 | |
|   }
 | |
| }
 | |
| 
 | |
| void DWARFDebugFrame::parse(DataExtractor Data) {
 | |
|   uint32_t Offset = 0;
 | |
|   DenseMap<uint32_t, CIE *> CIEs;
 | |
| 
 | |
|   while (Data.isValidOffset(Offset)) {
 | |
|     uint32_t StartOffset = Offset;
 | |
| 
 | |
|     auto ReportError = [StartOffset](const char *ErrorMsg) {
 | |
|       std::string Str;
 | |
|       raw_string_ostream OS(Str);
 | |
|       OS << format(ErrorMsg, StartOffset);
 | |
|       OS.flush();
 | |
|       report_fatal_error(Str);
 | |
|     };
 | |
| 
 | |
|     bool IsDWARF64 = false;
 | |
|     uint64_t Length = Data.getU32(&Offset);
 | |
|     uint64_t Id;
 | |
| 
 | |
|     if (Length == UINT32_MAX) {
 | |
|       // DWARF-64 is distinguished by the first 32 bits of the initial length
 | |
|       // field being 0xffffffff. Then, the next 64 bits are the actual entry
 | |
|       // length.
 | |
|       IsDWARF64 = true;
 | |
|       Length = Data.getU64(&Offset);
 | |
|     }
 | |
| 
 | |
|     // At this point, Offset points to the next field after Length.
 | |
|     // Length is the structure size excluding itself. Compute an offset one
 | |
|     // past the end of the structure (needed to know how many instructions to
 | |
|     // read).
 | |
|     // TODO: For honest DWARF64 support, DataExtractor will have to treat
 | |
|     //       offset_ptr as uint64_t*
 | |
|     uint32_t StartStructureOffset = Offset;
 | |
|     uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length);
 | |
| 
 | |
|     // The Id field's size depends on the DWARF format
 | |
|     Id = Data.getUnsigned(&Offset, (IsDWARF64 && !IsEH) ? 8 : 4);
 | |
|     bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) ||
 | |
|                   Id == DW_CIE_ID ||
 | |
|                   (IsEH && !Id));
 | |
| 
 | |
|     if (IsCIE) {
 | |
|       uint8_t Version = Data.getU8(&Offset);
 | |
|       const char *Augmentation = Data.getCStr(&Offset);
 | |
|       StringRef AugmentationString(Augmentation ? Augmentation : "");
 | |
|       uint8_t AddressSize = Version < 4 ? Data.getAddressSize() :
 | |
|                                           Data.getU8(&Offset);
 | |
|       Data.setAddressSize(AddressSize);
 | |
|       uint8_t SegmentDescriptorSize = Version < 4 ? 0 : Data.getU8(&Offset);
 | |
|       uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset);
 | |
|       int64_t DataAlignmentFactor = Data.getSLEB128(&Offset);
 | |
|       uint64_t ReturnAddressRegister = Data.getULEB128(&Offset);
 | |
| 
 | |
|       // Parse the augmentation data for EH CIEs
 | |
|       StringRef AugmentationData("");
 | |
|       uint32_t FDEPointerEncoding = DW_EH_PE_omit;
 | |
|       uint32_t LSDAPointerEncoding = DW_EH_PE_omit;
 | |
|       if (IsEH) {
 | |
|         Optional<uint32_t> PersonalityEncoding;
 | |
|         Optional<uint64_t> Personality;
 | |
| 
 | |
|         Optional<uint64_t> AugmentationLength;
 | |
|         uint32_t StartAugmentationOffset;
 | |
|         uint32_t EndAugmentationOffset;
 | |
| 
 | |
|         // Walk the augmentation string to get all the augmentation data.
 | |
|         for (unsigned i = 0, e = AugmentationString.size(); i != e; ++i) {
 | |
|           switch (AugmentationString[i]) {
 | |
|             default:
 | |
|               ReportError("Unknown augmentation character in entry at %lx");
 | |
|             case 'L':
 | |
|               LSDAPointerEncoding = Data.getU8(&Offset);
 | |
|               break;
 | |
|             case 'P': {
 | |
|               if (Personality)
 | |
|                 ReportError("Duplicate personality in entry at %lx");
 | |
|               PersonalityEncoding = Data.getU8(&Offset);
 | |
|               Personality = readPointer(Data, Offset, *PersonalityEncoding);
 | |
|               break;
 | |
|             }
 | |
|             case 'R':
 | |
|               FDEPointerEncoding = Data.getU8(&Offset);
 | |
|               break;
 | |
|             case 'z':
 | |
|               if (i)
 | |
|                 ReportError("'z' must be the first character at %lx");
 | |
|               // Parse the augmentation length first.  We only parse it if
 | |
|               // the string contains a 'z'.
 | |
|               AugmentationLength = Data.getULEB128(&Offset);
 | |
|               StartAugmentationOffset = Offset;
 | |
|               EndAugmentationOffset = Offset +
 | |
|                 static_cast<uint32_t>(*AugmentationLength);
 | |
|           }
 | |
|         }
 | |
| 
 | |
|         if (AugmentationLength.hasValue()) {
 | |
|           if (Offset != EndAugmentationOffset)
 | |
|             ReportError("Parsing augmentation data at %lx failed");
 | |
| 
 | |
|           AugmentationData = Data.getData().slice(StartAugmentationOffset,
 | |
|                                                   EndAugmentationOffset);
 | |
|         }
 | |
|       }
 | |
| 
 | |
|       auto Cie = make_unique<CIE>(StartOffset, Length, Version,
 | |
|                                   AugmentationString, AddressSize,
 | |
|                                   SegmentDescriptorSize, CodeAlignmentFactor,
 | |
|                                   DataAlignmentFactor, ReturnAddressRegister,
 | |
|                                   AugmentationData, FDEPointerEncoding,
 | |
|                                   LSDAPointerEncoding);
 | |
|       CIEs[StartOffset] = Cie.get();
 | |
|       Entries.emplace_back(std::move(Cie));
 | |
|     } else {
 | |
|       // FDE
 | |
|       uint64_t CIEPointer = Id;
 | |
|       uint64_t InitialLocation = 0;
 | |
|       uint64_t AddressRange = 0;
 | |
|       CIE *Cie = CIEs[IsEH ? (StartStructureOffset - CIEPointer) : CIEPointer];
 | |
| 
 | |
|       if (IsEH) {
 | |
|         // The address size is encoded in the CIE we reference.
 | |
|         if (!Cie)
 | |
|           ReportError("Parsing FDE data at %lx failed due to missing CIE");
 | |
| 
 | |
|         InitialLocation = readPointer(Data, Offset,
 | |
|                                       Cie->getFDEPointerEncoding());
 | |
|         AddressRange = readPointer(Data, Offset,
 | |
|                                    Cie->getFDEPointerEncoding());
 | |
| 
 | |
|         StringRef AugmentationString = Cie->getAugmentationString();
 | |
|         if (!AugmentationString.empty()) {
 | |
|           // Parse the augmentation length and data for this FDE.
 | |
|           uint64_t AugmentationLength = Data.getULEB128(&Offset);
 | |
| 
 | |
|           uint32_t EndAugmentationOffset =
 | |
|             Offset + static_cast<uint32_t>(AugmentationLength);
 | |
| 
 | |
|           // Decode the LSDA if the CIE augmentation string said we should.
 | |
|           if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit)
 | |
|             readPointer(Data, Offset, Cie->getLSDAPointerEncoding());
 | |
| 
 | |
|           if (Offset != EndAugmentationOffset)
 | |
|             ReportError("Parsing augmentation data at %lx failed");
 | |
|         }
 | |
|       } else {
 | |
|         InitialLocation = Data.getAddress(&Offset);
 | |
|         AddressRange = Data.getAddress(&Offset);
 | |
|       }
 | |
| 
 | |
|       Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
 | |
|                                    InitialLocation, AddressRange,
 | |
|                                    Cie));
 | |
|     }
 | |
| 
 | |
|     Entries.back()->parseInstructions(Data, &Offset, EndStructureOffset);
 | |
| 
 | |
|     if (Offset != EndStructureOffset)
 | |
|       ReportError("Parsing entry instructions at %lx failed");
 | |
|   }
 | |
| }
 | |
| 
 | |
| 
 | |
| void DWARFDebugFrame::dump(raw_ostream &OS) const {
 | |
|   OS << "\n";
 | |
|   for (const auto &Entry : Entries) {
 | |
|     Entry->dumpHeader(OS);
 | |
|     Entry->dumpInstructions(OS);
 | |
|     OS << "\n";
 | |
|   }
 | |
| }
 | |
| 
 |