diff tools/llvm-readobj/ARMWinEHPrinter.cpp @ 171:66f3bfe93da9

git version 2c4ca6832fa6b306ee6a7010bfb80a3f2596f824
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Mon, 25 May 2020 11:07:02 +0900
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/llvm-readobj/ARMWinEHPrinter.cpp	Mon May 25 11:07:02 2020 +0900
@@ -0,0 +1,1110 @@
+//===-- ARMWinEHPrinter.cpp - Windows on ARM EH Data Printer ----*- 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
+//
+//===----------------------------------------------------------------------===//
+
+// Windows on ARM uses a series of serialised data structures (RuntimeFunction)
+// to create a table of information for unwinding.  In order to conserve space,
+// there are two different ways that this data is represented.
+//
+// For functions with canonical forms for the prologue and epilogue, the data
+// can be stored in a "packed" form.  In this case, the data is packed into the
+// RuntimeFunction's remaining 30-bits and can fully describe the entire frame.
+//
+//        +---------------------------------------+
+//        |         Function Entry Address        |
+//        +---------------------------------------+
+//        |           Packed Form Data            |
+//        +---------------------------------------+
+//
+// This layout is parsed by Decoder::dumpPackedEntry.  No unwind bytecode is
+// associated with such a frame as they can be derived from the provided data.
+// The decoder does not synthesize this data as it is unnecessary for the
+// purposes of validation, with the synthesis being required only by a proper
+// unwinder.
+//
+// For functions that are large or do not match canonical forms, the data is
+// split up into two portions, with the actual data residing in the "exception
+// data" table (.xdata) with a reference to the entry from the "procedure data"
+// (.pdata) entry.
+//
+// The exception data contains information about the frame setup, all of the
+// epilogue scopes (for functions for which there are multiple exit points) and
+// the associated exception handler.  Additionally, the entry contains byte-code
+// describing how to unwind the function (c.f. Decoder::decodeOpcodes).
+//
+//        +---------------------------------------+
+//        |         Function Entry Address        |
+//        +---------------------------------------+
+//        |      Exception Data Entry Address     |
+//        +---------------------------------------+
+//
+// This layout is parsed by Decoder::dumpUnpackedEntry.  Such an entry must
+// first resolve the exception data entry address.  This structure
+// (ExceptionDataRecord) has a variable sized header
+// (c.f. ARM::WinEH::HeaderWords) and encodes most of the same information as
+// the packed form.  However, because this information is insufficient to
+// synthesize the unwinding, there are associated unwinding bytecode which make
+// up the bulk of the Decoder.
+//
+// The decoder itself is table-driven, using the first byte to determine the
+// opcode and dispatching to the associated printing routine.  The bytecode
+// itself is a variable length instruction encoding that can fully describe the
+// state of the stack and the necessary operations for unwinding to the
+// beginning of the frame.
+//
+// The byte-code maintains a 1-1 instruction mapping, indicating both the width
+// of the instruction (Thumb2 instructions are variable length, 16 or 32 bits
+// wide) allowing the program to unwind from any point in the prologue, body, or
+// epilogue of the function.
+
+#include "ARMWinEHPrinter.h"
+#include "Error.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/ARMWinEH.h"
+#include "llvm/Support/Format.h"
+
+using namespace llvm;
+using namespace llvm::object;
+using namespace llvm::support;
+
+namespace llvm {
+raw_ostream &operator<<(raw_ostream &OS, const ARM::WinEH::ReturnType &RT) {
+  switch (RT) {
+  case ARM::WinEH::ReturnType::RT_POP:
+    OS << "pop {pc}";
+    break;
+  case ARM::WinEH::ReturnType::RT_B:
+    OS << "b target";
+    break;
+  case ARM::WinEH::ReturnType::RT_BW:
+    OS << "b.w target";
+    break;
+  case ARM::WinEH::ReturnType::RT_NoEpilogue:
+    OS << "(no epilogue)";
+    break;
+  }
+  return OS;
+}
+}
+
+static std::string formatSymbol(StringRef Name, uint64_t Address,
+                                uint64_t Offset = 0) {
+  std::string Buffer;
+  raw_string_ostream OS(Buffer);
+
+  if (!Name.empty())
+    OS << Name << " ";
+
+  if (Offset)
+    OS << format("+0x%X (0x%" PRIX64 ")", Offset, Address);
+  else if (!Name.empty())
+    OS << format("(0x%" PRIX64 ")", Address);
+  else
+    OS << format("0x%" PRIX64, Address);
+
+  return OS.str();
+}
+
+namespace llvm {
+namespace ARM {
+namespace WinEH {
+const size_t Decoder::PDataEntrySize = sizeof(RuntimeFunction);
+
+// TODO name the uops more appropriately
+const Decoder::RingEntry Decoder::Ring[] = {
+  { 0x80, 0x00, 1, &Decoder::opcode_0xxxxxxx },  // UOP_STACK_FREE (16-bit)
+  { 0xc0, 0x80, 2, &Decoder::opcode_10Lxxxxx },  // UOP_POP (32-bit)
+  { 0xf0, 0xc0, 1, &Decoder::opcode_1100xxxx },  // UOP_STACK_SAVE (16-bit)
+  { 0xf8, 0xd0, 1, &Decoder::opcode_11010Lxx },  // UOP_POP (16-bit)
+  { 0xf8, 0xd8, 1, &Decoder::opcode_11011Lxx },  // UOP_POP (32-bit)
+  { 0xf8, 0xe0, 1, &Decoder::opcode_11100xxx },  // UOP_VPOP (32-bit)
+  { 0xfc, 0xe8, 2, &Decoder::opcode_111010xx },  // UOP_STACK_FREE (32-bit)
+  { 0xfe, 0xec, 2, &Decoder::opcode_1110110L },  // UOP_POP (16-bit)
+  { 0xff, 0xee, 2, &Decoder::opcode_11101110 },  // UOP_MICROSOFT_SPECIFIC (16-bit)
+                                              // UOP_PUSH_MACHINE_FRAME
+                                              // UOP_PUSH_CONTEXT
+                                              // UOP_PUSH_TRAP_FRAME
+                                              // UOP_REDZONE_RESTORE_LR
+  { 0xff, 0xef, 2, &Decoder::opcode_11101111 },  // UOP_LDRPC_POSTINC (32-bit)
+  { 0xff, 0xf5, 2, &Decoder::opcode_11110101 },  // UOP_VPOP (32-bit)
+  { 0xff, 0xf6, 2, &Decoder::opcode_11110110 },  // UOP_VPOP (32-bit)
+  { 0xff, 0xf7, 3, &Decoder::opcode_11110111 },  // UOP_STACK_RESTORE (16-bit)
+  { 0xff, 0xf8, 4, &Decoder::opcode_11111000 },  // UOP_STACK_RESTORE (16-bit)
+  { 0xff, 0xf9, 3, &Decoder::opcode_11111001 },  // UOP_STACK_RESTORE (32-bit)
+  { 0xff, 0xfa, 4, &Decoder::opcode_11111010 },  // UOP_STACK_RESTORE (32-bit)
+  { 0xff, 0xfb, 1, &Decoder::opcode_11111011 },  // UOP_NOP (16-bit)
+  { 0xff, 0xfc, 1, &Decoder::opcode_11111100 },  // UOP_NOP (32-bit)
+  { 0xff, 0xfd, 1, &Decoder::opcode_11111101 },  // UOP_NOP (16-bit) / END
+  { 0xff, 0xfe, 1, &Decoder::opcode_11111110 },  // UOP_NOP (32-bit) / END
+  { 0xff, 0xff, 1, &Decoder::opcode_11111111 },  // UOP_END
+};
+
+
+// Unwind opcodes for ARM64.
+// https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling
+const Decoder::RingEntry Decoder::Ring64[] = {
+  { 0xe0, 0x00, 1, &Decoder::opcode_alloc_s },
+  { 0xe0, 0x20, 1, &Decoder::opcode_save_r19r20_x },
+  { 0xc0, 0x40, 1, &Decoder::opcode_save_fplr },
+  { 0xc0, 0x80, 1, &Decoder::opcode_save_fplr_x },
+  { 0xf8, 0xc0, 2, &Decoder::opcode_alloc_m },
+  { 0xfc, 0xc8, 2, &Decoder::opcode_save_regp },
+  { 0xfc, 0xcc, 2, &Decoder::opcode_save_regp_x },
+  { 0xfc, 0xd0, 2, &Decoder::opcode_save_reg },
+  { 0xfe, 0xd4, 2, &Decoder::opcode_save_reg_x },
+  { 0xfe, 0xd6, 2, &Decoder::opcode_save_lrpair },
+  { 0xfe, 0xd8, 2, &Decoder::opcode_save_fregp },
+  { 0xfe, 0xda, 2, &Decoder::opcode_save_fregp_x },
+  { 0xfe, 0xdc, 2, &Decoder::opcode_save_freg },
+  { 0xff, 0xde, 2, &Decoder::opcode_save_freg_x },
+  { 0xff, 0xe0, 4, &Decoder::opcode_alloc_l },
+  { 0xff, 0xe1, 1, &Decoder::opcode_setfp },
+  { 0xff, 0xe2, 2, &Decoder::opcode_addfp },
+  { 0xff, 0xe3, 1, &Decoder::opcode_nop },
+  { 0xff, 0xe4, 1, &Decoder::opcode_end },
+  { 0xff, 0xe5, 1, &Decoder::opcode_end_c },
+};
+
+void Decoder::printRegisters(const std::pair<uint16_t, uint32_t> &RegisterMask) {
+  static const char * const GPRRegisterNames[16] = {
+    "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+    "r11", "ip", "sp", "lr", "pc",
+  };
+
+  const uint16_t GPRMask = std::get<0>(RegisterMask);
+  const uint16_t VFPMask = std::get<1>(RegisterMask);
+
+  OS << '{';
+  bool Comma = false;
+  for (unsigned RI = 0, RE = 11; RI < RE; ++RI) {
+    if (GPRMask & (1 << RI)) {
+      if (Comma)
+        OS << ", ";
+      OS << GPRRegisterNames[RI];
+      Comma = true;
+    }
+  }
+  for (unsigned RI = 0, RE = 32; RI < RE; ++RI) {
+    if (VFPMask & (1 << RI)) {
+      if (Comma)
+        OS << ", ";
+      OS << "d" << unsigned(RI);
+      Comma = true;
+    }
+  }
+  for (unsigned RI = 11, RE = 16; RI < RE; ++RI) {
+    if (GPRMask & (1 << RI)) {
+      if (Comma)
+        OS << ", ";
+      OS << GPRRegisterNames[RI];
+      Comma = true;
+    }
+  }
+  OS << '}';
+}
+
+ErrorOr<object::SectionRef>
+Decoder::getSectionContaining(const COFFObjectFile &COFF, uint64_t VA) {
+  for (const auto &Section : COFF.sections()) {
+    uint64_t Address = Section.getAddress();
+    uint64_t Size = Section.getSize();
+
+    if (VA >= Address && (VA - Address) <= Size)
+      return Section;
+  }
+  return readobj_error::unknown_symbol;
+}
+
+ErrorOr<object::SymbolRef> Decoder::getSymbol(const COFFObjectFile &COFF,
+                                              uint64_t VA, bool FunctionOnly) {
+  for (const auto &Symbol : COFF.symbols()) {
+    Expected<SymbolRef::Type> Type = Symbol.getType();
+    if (!Type)
+      return errorToErrorCode(Type.takeError());
+    if (FunctionOnly && *Type != SymbolRef::ST_Function)
+      continue;
+
+    Expected<uint64_t> Address = Symbol.getAddress();
+    if (!Address)
+      return errorToErrorCode(Address.takeError());
+    if (*Address == VA)
+      return Symbol;
+  }
+  return readobj_error::unknown_symbol;
+}
+
+ErrorOr<SymbolRef> Decoder::getRelocatedSymbol(const COFFObjectFile &,
+                                               const SectionRef &Section,
+                                               uint64_t Offset) {
+  for (const auto &Relocation : Section.relocations()) {
+    uint64_t RelocationOffset = Relocation.getOffset();
+    if (RelocationOffset == Offset)
+      return *Relocation.getSymbol();
+  }
+  return readobj_error::unknown_symbol;
+}
+
+bool Decoder::opcode_0xxxxxxx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint8_t Imm = OC[Offset] & 0x7f;
+  SW.startLine() << format("0x%02x                ; %s sp, #(%u * 4)\n",
+                           OC[Offset],
+                           static_cast<const char *>(Prologue ? "sub" : "add"),
+                           Imm);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_10Lxxxxx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  unsigned Link = (OC[Offset] & 0x20) >> 5;
+  uint16_t RegisterMask = (Link << (Prologue ? 14 : 15))
+                        | ((OC[Offset + 0] & 0x1f) << 8)
+                        | ((OC[Offset + 1] & 0xff) << 0);
+  assert((~RegisterMask & (1 << 13)) && "sp must not be set");
+  assert((~RegisterMask & (1 << (Prologue ? 15 : 14))) && "pc must not be set");
+
+  SW.startLine() << format("0x%02x 0x%02x           ; %s.w ",
+                           OC[Offset + 0], OC[Offset + 1],
+                           Prologue ? "push" : "pop");
+  printRegisters(std::make_pair(RegisterMask, 0));
+  OS << '\n';
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_1100xxxx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  if (Prologue)
+    SW.startLine() << format("0x%02x                ; mov r%u, sp\n",
+                             OC[Offset], OC[Offset] & 0xf);
+  else
+    SW.startLine() << format("0x%02x                ; mov sp, r%u\n",
+                             OC[Offset], OC[Offset] & 0xf);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_11010Lxx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  unsigned Link = (OC[Offset] & 0x4) >> 3;
+  unsigned Count = (OC[Offset] & 0x3);
+
+  uint16_t GPRMask = (Link << (Prologue ? 14 : 15))
+                   | (((1 << (Count + 1)) - 1) << 4);
+
+  SW.startLine() << format("0x%02x                ; %s ", OC[Offset],
+                           Prologue ? "push" : "pop");
+  printRegisters(std::make_pair(GPRMask, 0));
+  OS << '\n';
+
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_11011Lxx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  unsigned Link = (OC[Offset] & 0x4) >> 2;
+  unsigned Count = (OC[Offset] & 0x3) + 4;
+
+  uint16_t GPRMask = (Link << (Prologue ? 14 : 15))
+                   | (((1 << (Count + 1)) - 1) << 4);
+
+  SW.startLine() << format("0x%02x                ; %s.w ", OC[Offset],
+                           Prologue ? "push" : "pop");
+  printRegisters(std::make_pair(GPRMask, 0));
+  OS << '\n';
+
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_11100xxx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  unsigned High = (OC[Offset] & 0x7);
+  uint32_t VFPMask = (((1 << (High + 1)) - 1) << 8);
+
+  SW.startLine() << format("0x%02x                ; %s ", OC[Offset],
+                           Prologue ? "vpush" : "vpop");
+  printRegisters(std::make_pair(0, VFPMask));
+  OS << '\n';
+
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_111010xx(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint16_t Imm = ((OC[Offset + 0] & 0x03) << 8) | ((OC[Offset + 1] & 0xff) << 0);
+
+  SW.startLine() << format("0x%02x 0x%02x           ; %s.w sp, #(%u * 4)\n",
+                           OC[Offset + 0], OC[Offset + 1],
+                           static_cast<const char *>(Prologue ? "sub" : "add"),
+                           Imm);
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_1110110L(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint8_t GPRMask = ((OC[Offset + 0] & 0x01) << (Prologue ? 14 : 15))
+                  | ((OC[Offset + 1] & 0xff) << 0);
+
+  SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
+                           OC[Offset + 1], Prologue ? "push" : "pop");
+  printRegisters(std::make_pair(GPRMask, 0));
+  OS << '\n';
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_11101110(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  assert(!Prologue && "may not be used in prologue");
+
+  if (OC[Offset + 1] & 0xf0)
+    SW.startLine() << format("0x%02x 0x%02x           ; reserved\n",
+                             OC[Offset + 0], OC[Offset +  1]);
+  else
+    SW.startLine()
+      << format("0x%02x 0x%02x           ; microsoft-specific (type: %u)\n",
+                OC[Offset + 0], OC[Offset + 1], OC[Offset + 1] & 0x0f);
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_11101111(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  assert(!Prologue && "may not be used in prologue");
+
+  if (OC[Offset + 1] & 0xf0)
+    SW.startLine() << format("0x%02x 0x%02x           ; reserved\n",
+                             OC[Offset + 0], OC[Offset +  1]);
+  else
+    SW.startLine()
+      << format("0x%02x 0x%02x           ; ldr.w lr, [sp], #%u\n",
+                OC[Offset + 0], OC[Offset + 1], OC[Offset + 1] << 2);
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_11110101(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  unsigned Start = (OC[Offset + 1] & 0xf0) >> 4;
+  unsigned End = (OC[Offset + 1] & 0x0f) >> 0;
+  uint32_t VFPMask = ((1 << (End - Start)) - 1) << Start;
+
+  SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
+                           OC[Offset + 1], Prologue ? "vpush" : "vpop");
+  printRegisters(std::make_pair(0, VFPMask));
+  OS << '\n';
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_11110110(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  unsigned Start = (OC[Offset + 1] & 0xf0) >> 4;
+  unsigned End = (OC[Offset + 1] & 0x0f) >> 0;
+  uint32_t VFPMask = ((1 << (End - Start)) - 1) << 16;
+
+  SW.startLine() << format("0x%02x 0x%02x           ; %s ", OC[Offset + 0],
+                           OC[Offset + 1], Prologue ? "vpush" : "vpop");
+  printRegisters(std::make_pair(0, VFPMask));
+  OS << '\n';
+
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_11110111(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint32_t Imm = (OC[Offset + 1] << 8) | (OC[Offset + 2] << 0);
+
+  SW.startLine() << format("0x%02x 0x%02x 0x%02x      ; %s sp, sp, #(%u * 4)\n",
+                           OC[Offset + 0], OC[Offset + 1], OC[Offset + 2],
+                           static_cast<const char *>(Prologue ? "sub" : "add"),
+                           Imm);
+
+  Offset += 3;
+  return false;
+}
+
+bool Decoder::opcode_11111000(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint32_t Imm = (OC[Offset + 1] << 16)
+               | (OC[Offset + 2] << 8)
+               | (OC[Offset + 3] << 0);
+
+  SW.startLine()
+    << format("0x%02x 0x%02x 0x%02x 0x%02x ; %s sp, sp, #(%u * 4)\n",
+              OC[Offset + 0], OC[Offset + 1], OC[Offset + 2], OC[Offset + 3],
+              static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
+
+  Offset += 4;
+  return false;
+}
+
+bool Decoder::opcode_11111001(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint32_t Imm = (OC[Offset + 1] << 8) | (OC[Offset + 2] << 0);
+
+  SW.startLine()
+    << format("0x%02x 0x%02x 0x%02x      ; %s.w sp, sp, #(%u * 4)\n",
+              OC[Offset + 0], OC[Offset + 1], OC[Offset + 2],
+              static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
+
+  Offset += 3;
+  return false;
+}
+
+bool Decoder::opcode_11111010(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint32_t Imm = (OC[Offset + 1] << 16)
+               | (OC[Offset + 2] << 8)
+               | (OC[Offset + 3] << 0);
+
+  SW.startLine()
+    << format("0x%02x 0x%02x 0x%02x 0x%02x ; %s.w sp, sp, #(%u * 4)\n",
+              OC[Offset + 0], OC[Offset + 1], OC[Offset + 2], OC[Offset + 3],
+              static_cast<const char *>(Prologue ? "sub" : "add"), Imm);
+
+  Offset += 4;
+  return false;
+}
+
+bool Decoder::opcode_11111011(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  SW.startLine() << format("0x%02x                ; nop\n", OC[Offset]);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_11111100(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  SW.startLine() << format("0x%02x                ; nop.w\n", OC[Offset]);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_11111101(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  SW.startLine() << format("0x%02x                ; b\n", OC[Offset]);
+  ++Offset;
+  return true;
+}
+
+bool Decoder::opcode_11111110(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  SW.startLine() << format("0x%02x                ; b.w\n", OC[Offset]);
+  ++Offset;
+  return true;
+}
+
+bool Decoder::opcode_11111111(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  ++Offset;
+  return true;
+}
+
+// ARM64 unwind codes start here.
+bool Decoder::opcode_alloc_s(const uint8_t *OC, unsigned &Offset,
+                             unsigned Length, bool Prologue) {
+  uint32_t NumBytes = (OC[Offset] & 0x1F) << 4;
+  SW.startLine() << format("0x%02x                ; %s sp, #%u\n", OC[Offset],
+                           static_cast<const char *>(Prologue ? "sub" : "add"),
+                           NumBytes);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_save_r19r20_x(const uint8_t *OC, unsigned &Offset,
+                                   unsigned Length, bool Prologue) {
+  uint32_t Off = (OC[Offset] & 0x1F) << 3;
+  if (Prologue)
+    SW.startLine() << format(
+        "0x%02x                ; stp x19, x20, [sp, #-%u]!\n", OC[Offset], Off);
+  else
+    SW.startLine() << format(
+        "0x%02x                ; ldp x19, x20, [sp], #%u\n", OC[Offset], Off);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_save_fplr(const uint8_t *OC, unsigned &Offset,
+                               unsigned Length, bool Prologue) {
+  uint32_t Off = (OC[Offset] & 0x3F) << 3;
+  SW.startLine() << format(
+      "0x%02x                ; %s x29, x30, [sp, #%u]\n", OC[Offset],
+      static_cast<const char *>(Prologue ? "stp" : "ldp"), Off);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_save_fplr_x(const uint8_t *OC, unsigned &Offset,
+                                 unsigned Length, bool Prologue) {
+  uint32_t Off = ((OC[Offset] & 0x3F) + 1) << 3;
+  if (Prologue)
+    SW.startLine() << format(
+        "0x%02x                ; stp x29, x30, [sp, #-%u]!\n", OC[Offset], Off);
+  else
+    SW.startLine() << format(
+        "0x%02x                ; ldp x29, x30, [sp], #%u\n", OC[Offset], Off);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_alloc_m(const uint8_t *OC, unsigned &Offset,
+                             unsigned Length, bool Prologue) {
+  uint32_t NumBytes = ((OC[Offset] & 0x07) << 8);
+  NumBytes |= (OC[Offset + 1] & 0xFF);
+  NumBytes <<= 4;
+  SW.startLine() << format("0x%02x%02x              ; %s sp, #%u\n",
+                           OC[Offset], OC[Offset + 1],
+                           static_cast<const char *>(Prologue ? "sub" : "add"),
+                           NumBytes);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_regp(const uint8_t *OC, unsigned &Offset,
+                               unsigned Length, bool Prologue) {
+  uint32_t Reg = ((OC[Offset] & 0x03) << 8);
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg += 19;
+  uint32_t Off = (OC[Offset + 1] & 0x3F) << 3;
+  SW.startLine() << format(
+      "0x%02x%02x              ; %s x%u, x%u, [sp, #%u]\n",
+      OC[Offset], OC[Offset + 1],
+      static_cast<const char *>(Prologue ? "stp" : "ldp"), Reg, Reg + 1, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_regp_x(const uint8_t *OC, unsigned &Offset,
+                                 unsigned Length, bool Prologue) {
+  uint32_t Reg = ((OC[Offset] & 0x03) << 8);
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg += 19;
+  uint32_t Off = ((OC[Offset + 1] & 0x3F) + 1) << 3;
+  if (Prologue)
+    SW.startLine() << format(
+        "0x%02x%02x              ; stp x%u, x%u, [sp, #-%u]!\n",
+        OC[Offset], OC[Offset + 1], Reg,
+        Reg + 1, Off);
+  else
+    SW.startLine() << format(
+        "0x%02x%02x              ; ldp x%u, x%u, [sp], #%u\n",
+        OC[Offset], OC[Offset + 1], Reg,
+        Reg + 1, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_reg(const uint8_t *OC, unsigned &Offset,
+                              unsigned Length, bool Prologue) {
+  uint32_t Reg = (OC[Offset] & 0x03) << 8;
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg += 19;
+  uint32_t Off = (OC[Offset + 1] & 0x3F) << 3;
+  SW.startLine() << format("0x%02x%02x              ; %s x%u, [sp, #%u]\n",
+                           OC[Offset], OC[Offset + 1],
+                           static_cast<const char *>(Prologue ? "str" : "ldr"),
+                           Reg, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_reg_x(const uint8_t *OC, unsigned &Offset,
+                                unsigned Length, bool Prologue) {
+  uint32_t Reg = (OC[Offset] & 0x01) << 8;
+  Reg |= (OC[Offset + 1] & 0xE0);
+  Reg >>= 5;
+  Reg += 19;
+  uint32_t Off = ((OC[Offset + 1] & 0x1F) + 1) << 3;
+  if (Prologue)
+    SW.startLine() << format("0x%02x%02x              ; str x%u, [sp, #%u]!\n",
+                             OC[Offset], OC[Offset + 1], Reg, Off);
+  else
+    SW.startLine() << format("0x%02x%02x              ; ldr x%u, [sp], #%u\n",
+                             OC[Offset], OC[Offset + 1], Reg, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_lrpair(const uint8_t *OC, unsigned &Offset,
+                                 unsigned Length, bool Prologue) {
+  uint32_t Reg = (OC[Offset] & 0x01) << 8;
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg *= 2;
+  Reg += 19;
+  uint32_t Off = (OC[Offset + 1] & 0x3F) << 3;
+  SW.startLine() << format("0x%02x%02x              ; %s x%u, lr, [sp, #%u]\n",
+                           OC[Offset], OC[Offset + 1],
+                           static_cast<const char *>(Prologue ? "stp" : "ldp"),
+                           Reg, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_fregp(const uint8_t *OC, unsigned &Offset,
+                                unsigned Length, bool Prologue) {
+  uint32_t Reg = (OC[Offset] & 0x01) << 8;
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg += 8;
+  uint32_t Off = (OC[Offset + 1] & 0x3F) << 3;
+  SW.startLine() << format("0x%02x%02x              ; %s d%u, d%u, [sp, #%u]\n",
+                           OC[Offset], OC[Offset + 1],
+                           static_cast<const char *>(Prologue ? "stp" : "ldp"),
+                           Reg, Reg + 1, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_fregp_x(const uint8_t *OC, unsigned &Offset,
+                                  unsigned Length, bool Prologue) {
+  uint32_t Reg = (OC[Offset] & 0x01) << 8;
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg += 8;
+  uint32_t Off = ((OC[Offset + 1] & 0x3F) + 1) << 3;
+  if (Prologue)
+    SW.startLine() << format(
+        "0x%02x%02x              ; stp d%u, d%u, [sp, #-%u]!\n", OC[Offset],
+        OC[Offset + 1], Reg, Reg + 1, Off);
+  else
+    SW.startLine() << format(
+        "0x%02x%02x              ; ldp d%u, d%u, [sp], #%u\n", OC[Offset],
+        OC[Offset + 1], Reg, Reg + 1, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_freg(const uint8_t *OC, unsigned &Offset,
+                               unsigned Length, bool Prologue) {
+  uint32_t Reg = (OC[Offset] & 0x01) << 8;
+  Reg |= (OC[Offset + 1] & 0xC0);
+  Reg >>= 6;
+  Reg += 8;
+  uint32_t Off = (OC[Offset + 1] & 0x3F) << 3;
+  SW.startLine() << format("0x%02x%02x                ; %s d%u, [sp, #%u]\n",
+                           OC[Offset], OC[Offset + 1],
+                           static_cast<const char *>(Prologue ? "str" : "ldr"),
+                           Reg, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_save_freg_x(const uint8_t *OC, unsigned &Offset,
+                                 unsigned Length, bool Prologue) {
+  uint32_t Reg = ((OC[Offset + 1] & 0xE0) >> 5) + 8;
+  uint32_t Off = ((OC[Offset + 1] & 0x1F) + 1) << 3;
+  if (Prologue)
+    SW.startLine() << format(
+        "0x%02x%02x              ; str d%u, [sp, #-%u]!\n", OC[Offset],
+        OC[Offset + 1], Reg, Off);
+  else
+    SW.startLine() << format(
+        "0x%02x%02x              ; ldr d%u, [sp], #%u\n", OC[Offset],
+        OC[Offset + 1], Reg, Off);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_alloc_l(const uint8_t *OC, unsigned &Offset,
+                             unsigned Length, bool Prologue) {
+  unsigned Off =
+      (OC[Offset + 1] << 16) | (OC[Offset + 2] << 8) | (OC[Offset + 3] << 0);
+  Off <<= 4;
+  SW.startLine() << format(
+      "0x%02x%02x%02x%02x          ; %s sp, #%u\n", OC[Offset], OC[Offset + 1],
+      OC[Offset + 2], OC[Offset + 3],
+      static_cast<const char *>(Prologue ? "sub" : "add"), Off);
+  Offset += 4;
+  return false;
+}
+
+bool Decoder::opcode_setfp(const uint8_t *OC, unsigned &Offset, unsigned Length,
+                           bool Prologue) {
+  SW.startLine() << format("0x%02x                ; mov fp, sp\n", OC[Offset]);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_addfp(const uint8_t *OC, unsigned &Offset, unsigned Length,
+                           bool Prologue) {
+  unsigned NumBytes = OC[Offset + 1] << 3;
+  SW.startLine() << format("0x%02x%02x              ; add fp, sp, #%u\n",
+                           OC[Offset], OC[Offset + 1], NumBytes);
+  Offset += 2;
+  return false;
+}
+
+bool Decoder::opcode_nop(const uint8_t *OC, unsigned &Offset, unsigned Length,
+                         bool Prologue) {
+  SW.startLine() << format("0x%02x                ; nop\n", OC[Offset]);
+  ++Offset;
+  return false;
+}
+
+bool Decoder::opcode_end(const uint8_t *OC, unsigned &Offset, unsigned Length,
+                         bool Prologue) {
+  SW.startLine() << format("0x%02x                ; end\n", OC[Offset]);
+  ++Offset;
+  return true;
+}
+
+bool Decoder::opcode_end_c(const uint8_t *OC, unsigned &Offset, unsigned Length,
+                           bool Prologue) {
+  SW.startLine() << format("0x%02x                ; end_c\n", OC[Offset]);
+  ++Offset;
+  return true;
+}
+
+void Decoder::decodeOpcodes(ArrayRef<uint8_t> Opcodes, unsigned Offset,
+                            bool Prologue) {
+  assert((!Prologue || Offset == 0) && "prologue should always use offset 0");
+  const RingEntry* DecodeRing = isAArch64 ? Ring64 : Ring;
+  bool Terminated = false;
+  for (unsigned OI = Offset, OE = Opcodes.size(); !Terminated && OI < OE; ) {
+    for (unsigned DI = 0;; ++DI) {
+      if ((isAArch64 && (DI >= array_lengthof(Ring64))) ||
+          (!isAArch64 && (DI >= array_lengthof(Ring)))) {
+        SW.startLine() << format("0x%02x                ; Bad opcode!\n",
+                                 Opcodes.data()[OI]);
+        ++OI;
+        break;
+      }
+
+      if ((Opcodes[OI] & DecodeRing[DI].Mask) == DecodeRing[DI].Value) {
+        if (OI + DecodeRing[DI].Length > OE) {
+          SW.startLine() << format("Opcode 0x%02x goes past the unwind data\n",
+                                    Opcodes[OI]);
+          OI += DecodeRing[DI].Length;
+          break;
+        }
+        Terminated =
+            (this->*DecodeRing[DI].Routine)(Opcodes.data(), OI, 0, Prologue);
+        break;
+      }
+    }
+  }
+}
+
+bool Decoder::dumpXDataRecord(const COFFObjectFile &COFF,
+                              const SectionRef &Section,
+                              uint64_t FunctionAddress, uint64_t VA) {
+  ArrayRef<uint8_t> Contents;
+  if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
+    return false;
+
+  uint64_t SectionVA = Section.getAddress();
+  uint64_t Offset = VA - SectionVA;
+  const ulittle32_t *Data =
+    reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
+
+  // Sanity check to ensure that the .xdata header is present.
+  // A header is one or two words, followed by at least one word to describe
+  // the unwind codes. Applicable to both ARM and AArch64.
+  if (Contents.size() - Offset < 8)
+    report_fatal_error(".xdata must be at least 8 bytes in size");
+
+  const ExceptionDataRecord XData(Data, isAArch64);
+  DictScope XRS(SW, "ExceptionData");
+  SW.printNumber("FunctionLength",
+                 isAArch64 ? XData.FunctionLengthInBytesAArch64() :
+                 XData.FunctionLengthInBytesARM());
+  SW.printNumber("Version", XData.Vers());
+  SW.printBoolean("ExceptionData", XData.X());
+  SW.printBoolean("EpiloguePacked", XData.E());
+  if (!isAArch64)
+    SW.printBoolean("Fragment", XData.F());
+  SW.printNumber(XData.E() ? "EpilogueOffset" : "EpilogueScopes",
+                 XData.EpilogueCount());
+  uint64_t ByteCodeLength = XData.CodeWords() * sizeof(uint32_t);
+  SW.printNumber("ByteCodeLength", ByteCodeLength);
+
+  if ((int64_t)(Contents.size() - Offset - 4 * HeaderWords(XData) -
+                (XData.E() ? 0 : XData.EpilogueCount() * 4) -
+                (XData.X() ? 8 : 0)) < (int64_t)ByteCodeLength) {
+    SW.flush();
+    report_fatal_error("Malformed unwind data");
+  }
+
+  if (XData.E()) {
+    ArrayRef<uint8_t> UC = XData.UnwindByteCode();
+    if (isAArch64 || !XData.F()) {
+      ListScope PS(SW, "Prologue");
+      decodeOpcodes(UC, 0, /*Prologue=*/true);
+    }
+    if (XData.EpilogueCount()) {
+      ListScope ES(SW, "Epilogue");
+      decodeOpcodes(UC, XData.EpilogueCount(), /*Prologue=*/false);
+    }
+  } else {
+    {
+      ListScope PS(SW, "Prologue");
+      decodeOpcodes(XData.UnwindByteCode(), 0, /*Prologue=*/true);
+    }
+    ArrayRef<ulittle32_t> EpilogueScopes = XData.EpilogueScopes();
+    ListScope ESS(SW, "EpilogueScopes");
+    for (const EpilogueScope ES : EpilogueScopes) {
+      DictScope ESES(SW, "EpilogueScope");
+      SW.printNumber("StartOffset", ES.EpilogueStartOffset());
+      if (!isAArch64)
+        SW.printNumber("Condition", ES.Condition());
+      SW.printNumber("EpilogueStartIndex",
+                     isAArch64 ? ES.EpilogueStartIndexAArch64()
+                               : ES.EpilogueStartIndexARM());
+      if (ES.ES & ~0xffc3ffff)
+        SW.printNumber("ReservedBits", (ES.ES >> 18) & 0xF);
+
+      ListScope Opcodes(SW, "Opcodes");
+      decodeOpcodes(XData.UnwindByteCode(),
+                    isAArch64 ? ES.EpilogueStartIndexAArch64()
+                              : ES.EpilogueStartIndexARM(),
+                    /*Prologue=*/false);
+    }
+  }
+
+  if (XData.X()) {
+    const uint32_t Address = XData.ExceptionHandlerRVA();
+    const uint32_t Parameter = XData.ExceptionHandlerParameter();
+    const size_t HandlerOffset = HeaderWords(XData)
+                               + (XData.E() ? 0 : XData.EpilogueCount())
+                               + XData.CodeWords();
+
+    ErrorOr<SymbolRef> Symbol = getRelocatedSymbol(
+        COFF, Section, Offset + HandlerOffset * sizeof(uint32_t));
+    if (!Symbol)
+      Symbol = getSymbol(COFF, Address, /*FunctionOnly=*/true);
+    if (!Symbol) {
+      ListScope EHS(SW, "ExceptionHandler");
+      SW.printString("Routine", "(null)");
+      return true;
+    }
+
+    Expected<StringRef> Name = Symbol->getName();
+    if (!Name) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(Name.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+
+    ListScope EHS(SW, "ExceptionHandler");
+    SW.printString("Routine", formatSymbol(*Name, Address));
+    SW.printHex("Parameter", Parameter);
+  }
+
+  return true;
+}
+
+bool Decoder::dumpUnpackedEntry(const COFFObjectFile &COFF,
+                                const SectionRef Section, uint64_t Offset,
+                                unsigned Index, const RuntimeFunction &RF) {
+  assert(RF.Flag() == RuntimeFunctionFlag::RFF_Unpacked &&
+         "packed entry cannot be treated as an unpacked entry");
+
+  ErrorOr<SymbolRef> Function = getRelocatedSymbol(COFF, Section, Offset);
+  if (!Function)
+    Function = getSymbol(COFF, RF.BeginAddress, /*FunctionOnly=*/true);
+
+  ErrorOr<SymbolRef> XDataRecord = getRelocatedSymbol(COFF, Section, Offset + 4);
+  if (!XDataRecord)
+    XDataRecord = getSymbol(COFF, RF.ExceptionInformationRVA());
+
+  if (!RF.BeginAddress && !Function)
+    return false;
+  if (!RF.UnwindData && !XDataRecord)
+    return false;
+
+  StringRef FunctionName;
+  uint64_t FunctionAddress;
+  if (Function) {
+    Expected<StringRef> FunctionNameOrErr = Function->getName();
+    if (!FunctionNameOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(FunctionNameOrErr.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+    FunctionName = *FunctionNameOrErr;
+    Expected<uint64_t> FunctionAddressOrErr = Function->getAddress();
+    if (!FunctionAddressOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(FunctionAddressOrErr.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+    FunctionAddress = *FunctionAddressOrErr;
+  } else {
+    FunctionAddress = COFF.getImageBase() + RF.BeginAddress;
+  }
+
+  SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
+
+  if (XDataRecord) {
+    Expected<StringRef> Name = XDataRecord->getName();
+    if (!Name) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(Name.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+
+    Expected<uint64_t> AddressOrErr = XDataRecord->getAddress();
+    if (!AddressOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(AddressOrErr.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+    uint64_t Address = *AddressOrErr;
+
+    SW.printString("ExceptionRecord", formatSymbol(*Name, Address));
+
+    Expected<section_iterator> SIOrErr = XDataRecord->getSection();
+    if (!SIOrErr) {
+      // TODO: Actually report errors helpfully.
+      consumeError(SIOrErr.takeError());
+      return false;
+    }
+    section_iterator SI = *SIOrErr;
+
+    // FIXME: Do we need to add an offset from the relocation?
+    return dumpXDataRecord(COFF, *SI, FunctionAddress,
+                           RF.ExceptionInformationRVA());
+  } else {
+    uint64_t Address = COFF.getImageBase() + RF.ExceptionInformationRVA();
+    SW.printString("ExceptionRecord", formatSymbol("", Address));
+
+    ErrorOr<SectionRef> Section = getSectionContaining(COFF, Address);
+    if (!Section)
+      return false;
+
+    return dumpXDataRecord(COFF, *Section, FunctionAddress, Address);
+  }
+}
+
+bool Decoder::dumpPackedEntry(const object::COFFObjectFile &COFF,
+                              const SectionRef Section, uint64_t Offset,
+                              unsigned Index, const RuntimeFunction &RF) {
+  assert((RF.Flag() == RuntimeFunctionFlag::RFF_Packed ||
+          RF.Flag() == RuntimeFunctionFlag::RFF_PackedFragment) &&
+         "unpacked entry cannot be treated as a packed entry");
+
+  ErrorOr<SymbolRef> Function = getRelocatedSymbol(COFF, Section, Offset);
+  if (!Function)
+    Function = getSymbol(COFF, RF.BeginAddress, /*FunctionOnly=*/true);
+
+  StringRef FunctionName;
+  uint64_t FunctionAddress;
+  if (Function) {
+    Expected<StringRef> FunctionNameOrErr = Function->getName();
+    if (!FunctionNameOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(FunctionNameOrErr.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+    FunctionName = *FunctionNameOrErr;
+    Expected<uint64_t> FunctionAddressOrErr = Function->getAddress();
+    if (!FunctionAddressOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(FunctionAddressOrErr.takeError(), OS);
+      OS.flush();
+      report_fatal_error(Buf);
+    }
+    FunctionAddress = *FunctionAddressOrErr;
+  } else {
+    FunctionAddress = COFF.getPE32Header()->ImageBase + RF.BeginAddress;
+  }
+
+  SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
+  if (!isAArch64)
+    SW.printBoolean("Fragment",
+                    RF.Flag() == RuntimeFunctionFlag::RFF_PackedFragment);
+  SW.printNumber("FunctionLength", RF.FunctionLength());
+  SW.startLine() << "ReturnType: " << RF.Ret() << '\n';
+  SW.printBoolean("HomedParameters", RF.H());
+  SW.startLine() << "SavedRegisters: ";
+                 printRegisters(SavedRegisterMask(RF));
+  OS << '\n';
+  SW.printNumber("StackAdjustment", StackAdjustment(RF) << 2);
+
+  return true;
+}
+
+bool Decoder::dumpProcedureDataEntry(const COFFObjectFile &COFF,
+                                     const SectionRef Section, unsigned Index,
+                                     ArrayRef<uint8_t> Contents) {
+  uint64_t Offset = PDataEntrySize * Index;
+  const ulittle32_t *Data =
+    reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
+
+  const RuntimeFunction Entry(Data);
+  DictScope RFS(SW, "RuntimeFunction");
+  if (Entry.Flag() == RuntimeFunctionFlag::RFF_Unpacked)
+    return dumpUnpackedEntry(COFF, Section, Offset, Index, Entry);
+  if (isAArch64) {
+    SW.startLine() << "Packed unwind data not yet supported for ARM64\n";
+    return true;
+  }
+  return dumpPackedEntry(COFF, Section, Offset, Index, Entry);
+}
+
+void Decoder::dumpProcedureData(const COFFObjectFile &COFF,
+                                const SectionRef Section) {
+  ArrayRef<uint8_t> Contents;
+  if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
+    return;
+
+  if (Contents.size() % PDataEntrySize) {
+    errs() << ".pdata content is not " << PDataEntrySize << "-byte aligned\n";
+    return;
+  }
+
+  for (unsigned EI = 0, EE = Contents.size() / PDataEntrySize; EI < EE; ++EI)
+    if (!dumpProcedureDataEntry(COFF, Section, EI, Contents))
+      break;
+}
+
+Error Decoder::dumpProcedureData(const COFFObjectFile &COFF) {
+  for (const auto &Section : COFF.sections()) {
+    Expected<StringRef> NameOrErr =
+        COFF.getSectionName(COFF.getCOFFSection(Section));
+    if (!NameOrErr)
+      return NameOrErr.takeError();
+
+    if (NameOrErr->startswith(".pdata"))
+      dumpProcedureData(COFF, Section);
+  }
+  return Error::success();
+}
+}
+}
+}