xref: /llvm-project/lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp (revision c4fb7180cbbe977f1ab1ce945a691550f8fdd1fb)
1 //===-- DisassemblerLLVMC.cpp ---------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "DisassemblerLLVMC.h"
10 
11 #include "llvm-c/Disassembler.h"
12 #include "llvm/ADT/SmallString.h"
13 #include "llvm/ADT/StringExtras.h"
14 #include "llvm/MC/MCAsmInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
17 #include "llvm/MC/MCDisassembler/MCExternalSymbolizer.h"
18 #include "llvm/MC/MCDisassembler/MCRelocationInfo.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/MC/MCInstPrinter.h"
21 #include "llvm/MC/MCInstrAnalysis.h"
22 #include "llvm/MC/MCInstrInfo.h"
23 #include "llvm/MC/MCRegisterInfo.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/MC/MCTargetOptions.h"
26 #include "llvm/MC/TargetRegistry.h"
27 #include "llvm/Support/ErrorHandling.h"
28 #include "llvm/Support/ScopedPrinter.h"
29 #include "llvm/Support/TargetSelect.h"
30 #include "llvm/TargetParser/AArch64TargetParser.h"
31 
32 #include "lldb/Core/Address.h"
33 #include "lldb/Core/Module.h"
34 #include "lldb/Symbol/SymbolContext.h"
35 #include "lldb/Target/ExecutionContext.h"
36 #include "lldb/Target/Process.h"
37 #include "lldb/Target/RegisterContext.h"
38 #include "lldb/Target/SectionLoadList.h"
39 #include "lldb/Target/StackFrame.h"
40 #include "lldb/Target/Target.h"
41 #include "lldb/Utility/DataExtractor.h"
42 #include "lldb/Utility/LLDBLog.h"
43 #include "lldb/Utility/Log.h"
44 #include "lldb/Utility/RegularExpression.h"
45 #include "lldb/Utility/Stream.h"
46 #include <optional>
47 
48 using namespace lldb;
49 using namespace lldb_private;
50 
51 LLDB_PLUGIN_DEFINE(DisassemblerLLVMC)
52 
53 class DisassemblerLLVMC::MCDisasmInstance {
54 public:
55   static std::unique_ptr<MCDisasmInstance>
56   Create(const char *triple, const char *cpu, const char *features_str,
57          unsigned flavor, DisassemblerLLVMC &owner);
58 
59   ~MCDisasmInstance() = default;
60 
61   uint64_t GetMCInst(const uint8_t *opcode_data, size_t opcode_data_len,
62                      lldb::addr_t pc, llvm::MCInst &mc_inst) const;
63   void PrintMCInst(llvm::MCInst &mc_inst, lldb::addr_t pc,
64                    std::string &inst_string, std::string &comments_string);
65   void SetStyle(bool use_hex_immed, HexImmediateStyle hex_style);
66   void SetUseColor(bool use_color);
67   bool GetUseColor() const;
68   bool CanBranch(llvm::MCInst &mc_inst) const;
69   bool HasDelaySlot(llvm::MCInst &mc_inst) const;
70   bool IsCall(llvm::MCInst &mc_inst) const;
71   bool IsLoad(llvm::MCInst &mc_inst) const;
72   bool IsAuthenticated(llvm::MCInst &mc_inst) const;
73 
74 private:
75   MCDisasmInstance(std::unique_ptr<llvm::MCInstrInfo> &&instr_info_up,
76                    std::unique_ptr<llvm::MCRegisterInfo> &&reg_info_up,
77                    std::unique_ptr<llvm::MCSubtargetInfo> &&subtarget_info_up,
78                    std::unique_ptr<llvm::MCAsmInfo> &&asm_info_up,
79                    std::unique_ptr<llvm::MCContext> &&context_up,
80                    std::unique_ptr<llvm::MCDisassembler> &&disasm_up,
81                    std::unique_ptr<llvm::MCInstPrinter> &&instr_printer_up,
82                    std::unique_ptr<llvm::MCInstrAnalysis> &&instr_analysis_up);
83 
84   std::unique_ptr<llvm::MCInstrInfo> m_instr_info_up;
85   std::unique_ptr<llvm::MCRegisterInfo> m_reg_info_up;
86   std::unique_ptr<llvm::MCSubtargetInfo> m_subtarget_info_up;
87   std::unique_ptr<llvm::MCAsmInfo> m_asm_info_up;
88   std::unique_ptr<llvm::MCContext> m_context_up;
89   std::unique_ptr<llvm::MCDisassembler> m_disasm_up;
90   std::unique_ptr<llvm::MCInstPrinter> m_instr_printer_up;
91   std::unique_ptr<llvm::MCInstrAnalysis> m_instr_analysis_up;
92 };
93 
94 namespace x86 {
95 
96 /// These are the three values deciding instruction control flow kind.
97 /// InstructionLengthDecode function decodes an instruction and get this struct.
98 ///
99 /// primary_opcode
100 ///    Primary opcode of the instruction.
101 ///    For one-byte opcode instruction, it's the first byte after prefix.
102 ///    For two- and three-byte opcodes, it's the second byte.
103 ///
104 /// opcode_len
105 ///    The length of opcode in bytes. Valid opcode lengths are 1, 2, or 3.
106 ///
107 /// modrm
108 ///    ModR/M byte of the instruction.
109 ///    Bits[7:6] indicate MOD. Bits[5:3] specify a register and R/M bits[2:0]
110 ///    may contain a register or specify an addressing mode, depending on MOD.
111 struct InstructionOpcodeAndModrm {
112   uint8_t primary_opcode;
113   uint8_t opcode_len;
114   uint8_t modrm;
115 };
116 
117 /// Determine the InstructionControlFlowKind based on opcode and modrm bytes.
118 /// Refer to http://ref.x86asm.net/coder.html for the full list of opcode and
119 /// instruction set.
120 ///
121 /// \param[in] opcode_and_modrm
122 ///    Contains primary_opcode byte, its length, and ModR/M byte.
123 ///    Refer to the struct InstructionOpcodeAndModrm for details.
124 ///
125 /// \return
126 ///   The control flow kind of the instruction or
127 ///   eInstructionControlFlowKindOther if the instruction doesn't affect
128 ///   the control flow of the program.
129 lldb::InstructionControlFlowKind
130 MapOpcodeIntoControlFlowKind(InstructionOpcodeAndModrm opcode_and_modrm) {
131   uint8_t opcode = opcode_and_modrm.primary_opcode;
132   uint8_t opcode_len = opcode_and_modrm.opcode_len;
133   uint8_t modrm = opcode_and_modrm.modrm;
134 
135   if (opcode_len > 2)
136     return lldb::eInstructionControlFlowKindOther;
137 
138   if (opcode >= 0x70 && opcode <= 0x7F) {
139     if (opcode_len == 1)
140       return lldb::eInstructionControlFlowKindCondJump;
141     else
142       return lldb::eInstructionControlFlowKindOther;
143   }
144 
145   if (opcode >= 0x80 && opcode <= 0x8F) {
146     if (opcode_len == 2)
147       return lldb::eInstructionControlFlowKindCondJump;
148     else
149       return lldb::eInstructionControlFlowKindOther;
150   }
151 
152   switch (opcode) {
153   case 0x9A:
154     if (opcode_len == 1)
155       return lldb::eInstructionControlFlowKindFarCall;
156     break;
157   case 0xFF:
158     if (opcode_len == 1) {
159       uint8_t modrm_reg = (modrm >> 3) & 7;
160       if (modrm_reg == 2)
161         return lldb::eInstructionControlFlowKindCall;
162       else if (modrm_reg == 3)
163         return lldb::eInstructionControlFlowKindFarCall;
164       else if (modrm_reg == 4)
165         return lldb::eInstructionControlFlowKindJump;
166       else if (modrm_reg == 5)
167         return lldb::eInstructionControlFlowKindFarJump;
168     }
169     break;
170   case 0xE8:
171     if (opcode_len == 1)
172       return lldb::eInstructionControlFlowKindCall;
173     break;
174   case 0xCD:
175   case 0xCC:
176   case 0xCE:
177   case 0xF1:
178     if (opcode_len == 1)
179       return lldb::eInstructionControlFlowKindFarCall;
180     break;
181   case 0xCF:
182     if (opcode_len == 1)
183       return lldb::eInstructionControlFlowKindFarReturn;
184     break;
185   case 0xE9:
186   case 0xEB:
187     if (opcode_len == 1)
188       return lldb::eInstructionControlFlowKindJump;
189     break;
190   case 0xEA:
191     if (opcode_len == 1)
192       return lldb::eInstructionControlFlowKindFarJump;
193     break;
194   case 0xE3:
195   case 0xE0:
196   case 0xE1:
197   case 0xE2:
198     if (opcode_len == 1)
199       return lldb::eInstructionControlFlowKindCondJump;
200     break;
201   case 0xC3:
202   case 0xC2:
203     if (opcode_len == 1)
204       return lldb::eInstructionControlFlowKindReturn;
205     break;
206   case 0xCB:
207   case 0xCA:
208     if (opcode_len == 1)
209       return lldb::eInstructionControlFlowKindFarReturn;
210     break;
211   case 0x05:
212   case 0x34:
213     if (opcode_len == 2)
214       return lldb::eInstructionControlFlowKindFarCall;
215     break;
216   case 0x35:
217   case 0x07:
218     if (opcode_len == 2)
219       return lldb::eInstructionControlFlowKindFarReturn;
220     break;
221   case 0x01:
222     if (opcode_len == 2) {
223       switch (modrm) {
224       case 0xc1:
225         return lldb::eInstructionControlFlowKindFarCall;
226       case 0xc2:
227       case 0xc3:
228         return lldb::eInstructionControlFlowKindFarReturn;
229       default:
230         break;
231       }
232     }
233     break;
234   default:
235     break;
236   }
237 
238   return lldb::eInstructionControlFlowKindOther;
239 }
240 
241 /// Decode an instruction into opcode, modrm and opcode_len.
242 /// Refer to http://ref.x86asm.net/coder.html for the instruction bytes layout.
243 /// Opcodes in x86 are generally the first byte of instruction, though two-byte
244 /// instructions and prefixes exist. ModR/M is the byte following the opcode
245 /// and adds additional information for how the instruction is executed.
246 ///
247 /// \param[in] inst_bytes
248 ///    Raw bytes of the instruction
249 ///
250 ///
251 /// \param[in] bytes_len
252 ///    The length of the inst_bytes array.
253 ///
254 /// \param[in] is_exec_mode_64b
255 ///    If true, the execution mode is 64 bit.
256 ///
257 /// \return
258 ///    Returns decoded instruction as struct InstructionOpcodeAndModrm, holding
259 ///    primary_opcode, opcode_len and modrm byte. Refer to the struct definition
260 ///    for more details.
261 ///    Otherwise if the given instruction is invalid, returns std::nullopt.
262 std::optional<InstructionOpcodeAndModrm>
263 InstructionLengthDecode(const uint8_t *inst_bytes, int bytes_len,
264                         bool is_exec_mode_64b) {
265   int op_idx = 0;
266   bool prefix_done = false;
267   InstructionOpcodeAndModrm ret = {0, 0, 0};
268 
269   // In most cases, the primary_opcode is the first byte of the instruction
270   // but some instructions have a prefix to be skipped for these calculations.
271   // The following mapping is inspired from libipt's instruction decoding logic
272   // in `src/pt_ild.c`
273   while (!prefix_done) {
274     if (op_idx >= bytes_len)
275       return std::nullopt;
276 
277     ret.primary_opcode = inst_bytes[op_idx];
278     switch (ret.primary_opcode) {
279     // prefix_ignore
280     case 0x26:
281     case 0x2e:
282     case 0x36:
283     case 0x3e:
284     case 0x64:
285     case 0x65:
286     // prefix_osz, prefix_asz
287     case 0x66:
288     case 0x67:
289     // prefix_lock, prefix_f2, prefix_f3
290     case 0xf0:
291     case 0xf2:
292     case 0xf3:
293       op_idx++;
294       break;
295 
296     // prefix_rex
297     case 0x40:
298     case 0x41:
299     case 0x42:
300     case 0x43:
301     case 0x44:
302     case 0x45:
303     case 0x46:
304     case 0x47:
305     case 0x48:
306     case 0x49:
307     case 0x4a:
308     case 0x4b:
309     case 0x4c:
310     case 0x4d:
311     case 0x4e:
312     case 0x4f:
313       if (is_exec_mode_64b)
314         op_idx++;
315       else
316         prefix_done = true;
317       break;
318 
319     // prefix_vex_c4, c5
320     case 0xc5:
321       if (!is_exec_mode_64b && (inst_bytes[op_idx + 1] & 0xc0) != 0xc0) {
322         prefix_done = true;
323         break;
324       }
325 
326       ret.opcode_len = 2;
327       ret.primary_opcode = inst_bytes[op_idx + 2];
328       ret.modrm = inst_bytes[op_idx + 3];
329       return ret;
330 
331     case 0xc4:
332       if (!is_exec_mode_64b && (inst_bytes[op_idx + 1] & 0xc0) != 0xc0) {
333         prefix_done = true;
334         break;
335       }
336       ret.opcode_len = inst_bytes[op_idx + 1] & 0x1f;
337       ret.primary_opcode = inst_bytes[op_idx + 3];
338       ret.modrm = inst_bytes[op_idx + 4];
339       return ret;
340 
341     // prefix_evex
342     case 0x62:
343       if (!is_exec_mode_64b && (inst_bytes[op_idx + 1] & 0xc0) != 0xc0) {
344         prefix_done = true;
345         break;
346       }
347       ret.opcode_len = inst_bytes[op_idx + 1] & 0x03;
348       ret.primary_opcode = inst_bytes[op_idx + 4];
349       ret.modrm = inst_bytes[op_idx + 5];
350       return ret;
351 
352     default:
353       prefix_done = true;
354       break;
355     }
356   } // prefix done
357 
358   ret.primary_opcode = inst_bytes[op_idx];
359   ret.modrm = inst_bytes[op_idx + 1];
360   ret.opcode_len = 1;
361 
362   // If the first opcode is 0F, it's two- or three- byte opcodes.
363   if (ret.primary_opcode == 0x0F) {
364     ret.primary_opcode = inst_bytes[++op_idx]; // get the next byte
365 
366     if (ret.primary_opcode == 0x38) {
367       ret.opcode_len = 3;
368       ret.primary_opcode = inst_bytes[++op_idx]; // get the next byte
369       ret.modrm = inst_bytes[op_idx + 1];
370     } else if (ret.primary_opcode == 0x3A) {
371       ret.opcode_len = 3;
372       ret.primary_opcode = inst_bytes[++op_idx];
373       ret.modrm = inst_bytes[op_idx + 1];
374     } else if ((ret.primary_opcode & 0xf8) == 0x38) {
375       ret.opcode_len = 0;
376       ret.primary_opcode = inst_bytes[++op_idx];
377       ret.modrm = inst_bytes[op_idx + 1];
378     } else if (ret.primary_opcode == 0x0F) {
379       ret.opcode_len = 3;
380       // opcode is 0x0F, no needs to update
381       ret.modrm = inst_bytes[op_idx + 1];
382     } else {
383       ret.opcode_len = 2;
384       ret.modrm = inst_bytes[op_idx + 1];
385     }
386   }
387 
388   return ret;
389 }
390 
391 lldb::InstructionControlFlowKind GetControlFlowKind(bool is_exec_mode_64b,
392                                                     Opcode m_opcode) {
393   std::optional<InstructionOpcodeAndModrm> ret;
394 
395   if (m_opcode.GetOpcodeBytes() == nullptr || m_opcode.GetByteSize() <= 0) {
396     // x86_64 and i386 instructions are categorized as Opcode::Type::eTypeBytes
397     return lldb::eInstructionControlFlowKindUnknown;
398   }
399 
400   // Opcode bytes will be decoded into primary_opcode, modrm and opcode length.
401   // These are the three values deciding instruction control flow kind.
402   ret = InstructionLengthDecode((const uint8_t *)m_opcode.GetOpcodeBytes(),
403                                 m_opcode.GetByteSize(), is_exec_mode_64b);
404   if (!ret)
405     return lldb::eInstructionControlFlowKindUnknown;
406   else
407     return MapOpcodeIntoControlFlowKind(*ret);
408 }
409 
410 } // namespace x86
411 
412 class InstructionLLVMC : public lldb_private::Instruction {
413 public:
414   InstructionLLVMC(DisassemblerLLVMC &disasm,
415                    const lldb_private::Address &address,
416                    AddressClass addr_class)
417       : Instruction(address, addr_class),
418         m_disasm_wp(std::static_pointer_cast<DisassemblerLLVMC>(
419             disasm.shared_from_this())) {}
420 
421   ~InstructionLLVMC() override = default;
422 
423   bool DoesBranch() override {
424     VisitInstruction();
425     return m_does_branch;
426   }
427 
428   bool HasDelaySlot() override {
429     VisitInstruction();
430     return m_has_delay_slot;
431   }
432 
433   bool IsLoad() override {
434     VisitInstruction();
435     return m_is_load;
436   }
437 
438   bool IsAuthenticated() override {
439     VisitInstruction();
440     return m_is_authenticated;
441   }
442 
443   DisassemblerLLVMC::MCDisasmInstance *GetDisasmToUse(bool &is_alternate_isa) {
444     DisassemblerScope disasm(*this);
445     return GetDisasmToUse(is_alternate_isa, disasm);
446   }
447 
448   size_t Decode(const lldb_private::Disassembler &disassembler,
449                 const lldb_private::DataExtractor &data,
450                 lldb::offset_t data_offset) override {
451     // All we have to do is read the opcode which can be easy for some
452     // architectures
453     bool got_op = false;
454     DisassemblerScope disasm(*this);
455     if (disasm) {
456       const ArchSpec &arch = disasm->GetArchitecture();
457       const lldb::ByteOrder byte_order = data.GetByteOrder();
458 
459       const uint32_t min_op_byte_size = arch.GetMinimumOpcodeByteSize();
460       const uint32_t max_op_byte_size = arch.GetMaximumOpcodeByteSize();
461       if (min_op_byte_size == max_op_byte_size) {
462         // Fixed size instructions, just read that amount of data.
463         if (!data.ValidOffsetForDataOfSize(data_offset, min_op_byte_size))
464           return false;
465 
466         switch (min_op_byte_size) {
467         case 1:
468           m_opcode.SetOpcode8(data.GetU8(&data_offset), byte_order);
469           got_op = true;
470           break;
471 
472         case 2:
473           m_opcode.SetOpcode16(data.GetU16(&data_offset), byte_order);
474           got_op = true;
475           break;
476 
477         case 4:
478           m_opcode.SetOpcode32(data.GetU32(&data_offset), byte_order);
479           got_op = true;
480           break;
481 
482         case 8:
483           m_opcode.SetOpcode64(data.GetU64(&data_offset), byte_order);
484           got_op = true;
485           break;
486 
487         default:
488           m_opcode.SetOpcodeBytes(data.PeekData(data_offset, min_op_byte_size),
489                                   min_op_byte_size);
490           got_op = true;
491           break;
492         }
493       }
494       if (!got_op) {
495         bool is_alternate_isa = false;
496         DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr =
497             GetDisasmToUse(is_alternate_isa, disasm);
498 
499         const llvm::Triple::ArchType machine = arch.GetMachine();
500         if (machine == llvm::Triple::arm || machine == llvm::Triple::thumb) {
501           if (machine == llvm::Triple::thumb || is_alternate_isa) {
502             uint32_t thumb_opcode = data.GetU16(&data_offset);
503             if ((thumb_opcode & 0xe000) != 0xe000 ||
504                 ((thumb_opcode & 0x1800u) == 0)) {
505               m_opcode.SetOpcode16(thumb_opcode, byte_order);
506               m_is_valid = true;
507             } else {
508               thumb_opcode <<= 16;
509               thumb_opcode |= data.GetU16(&data_offset);
510               m_opcode.SetOpcode16_2(thumb_opcode, byte_order);
511               m_is_valid = true;
512             }
513           } else {
514             m_opcode.SetOpcode32(data.GetU32(&data_offset), byte_order);
515             m_is_valid = true;
516           }
517         } else {
518           // The opcode isn't evenly sized, so we need to actually use the llvm
519           // disassembler to parse it and get the size.
520           uint8_t *opcode_data =
521               const_cast<uint8_t *>(data.PeekData(data_offset, 1));
522           const size_t opcode_data_len = data.BytesLeft(data_offset);
523           const addr_t pc = m_address.GetFileAddress();
524           llvm::MCInst inst;
525 
526           const size_t inst_size =
527               mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
528           if (inst_size == 0)
529             m_opcode.Clear();
530           else {
531             m_opcode.SetOpcodeBytes(opcode_data, inst_size);
532             m_is_valid = true;
533           }
534         }
535       }
536       return m_opcode.GetByteSize();
537     }
538     return 0;
539   }
540 
541   void AppendComment(std::string &description) {
542     if (m_comment.empty())
543       m_comment.swap(description);
544     else {
545       m_comment.append(", ");
546       m_comment.append(description);
547     }
548   }
549 
550   lldb::InstructionControlFlowKind
551   GetControlFlowKind(const lldb_private::ExecutionContext *exe_ctx) override {
552     DisassemblerScope disasm(*this, exe_ctx);
553     if (disasm){
554       if (disasm->GetArchitecture().GetMachine() == llvm::Triple::x86)
555         return x86::GetControlFlowKind(/*is_64b=*/false, m_opcode);
556       else if (disasm->GetArchitecture().GetMachine() == llvm::Triple::x86_64)
557         return x86::GetControlFlowKind(/*is_64b=*/true, m_opcode);
558     }
559 
560     return eInstructionControlFlowKindUnknown;
561   }
562 
563   void CalculateMnemonicOperandsAndComment(
564       const lldb_private::ExecutionContext *exe_ctx) override {
565     DataExtractor data;
566     const AddressClass address_class = GetAddressClass();
567 
568     if (m_opcode.GetData(data)) {
569       std::string out_string;
570       std::string markup_out_string;
571       std::string comment_string;
572       std::string markup_comment_string;
573 
574       DisassemblerScope disasm(*this, exe_ctx);
575       if (disasm) {
576         DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr;
577 
578         if (address_class == AddressClass::eCodeAlternateISA)
579           mc_disasm_ptr = disasm->m_alternate_disasm_up.get();
580         else
581           mc_disasm_ptr = disasm->m_disasm_up.get();
582 
583         lldb::addr_t pc = m_address.GetFileAddress();
584         m_using_file_addr = true;
585 
586         bool use_hex_immediates = true;
587         Disassembler::HexImmediateStyle hex_style = Disassembler::eHexStyleC;
588 
589         if (exe_ctx) {
590           Target *target = exe_ctx->GetTargetPtr();
591           if (target) {
592             use_hex_immediates = target->GetUseHexImmediates();
593             hex_style = target->GetHexImmediateStyle();
594 
595             const lldb::addr_t load_addr = m_address.GetLoadAddress(target);
596             if (load_addr != LLDB_INVALID_ADDRESS) {
597               pc = load_addr;
598               m_using_file_addr = false;
599             }
600           }
601         }
602 
603         const uint8_t *opcode_data = data.GetDataStart();
604         const size_t opcode_data_len = data.GetByteSize();
605         llvm::MCInst inst;
606         size_t inst_size =
607             mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
608 
609         if (inst_size > 0) {
610           mc_disasm_ptr->SetStyle(use_hex_immediates, hex_style);
611 
612           const bool saved_use_color = mc_disasm_ptr->GetUseColor();
613           mc_disasm_ptr->SetUseColor(false);
614           mc_disasm_ptr->PrintMCInst(inst, pc, out_string, comment_string);
615           mc_disasm_ptr->SetUseColor(true);
616           mc_disasm_ptr->PrintMCInst(inst, pc, markup_out_string,
617                                      markup_comment_string);
618           mc_disasm_ptr->SetUseColor(saved_use_color);
619 
620           if (!comment_string.empty()) {
621             AppendComment(comment_string);
622           }
623         }
624 
625         if (inst_size == 0) {
626           m_comment.assign("unknown opcode");
627           inst_size = m_opcode.GetByteSize();
628           StreamString mnemonic_strm;
629           lldb::offset_t offset = 0;
630           lldb::ByteOrder byte_order = data.GetByteOrder();
631           switch (inst_size) {
632           case 1: {
633             const uint8_t uval8 = data.GetU8(&offset);
634             m_opcode.SetOpcode8(uval8, byte_order);
635             m_opcode_name.assign(".byte");
636             mnemonic_strm.Printf("0x%2.2x", uval8);
637           } break;
638           case 2: {
639             const uint16_t uval16 = data.GetU16(&offset);
640             m_opcode.SetOpcode16(uval16, byte_order);
641             m_opcode_name.assign(".short");
642             mnemonic_strm.Printf("0x%4.4x", uval16);
643           } break;
644           case 4: {
645             const uint32_t uval32 = data.GetU32(&offset);
646             m_opcode.SetOpcode32(uval32, byte_order);
647             m_opcode_name.assign(".long");
648             mnemonic_strm.Printf("0x%8.8x", uval32);
649           } break;
650           case 8: {
651             const uint64_t uval64 = data.GetU64(&offset);
652             m_opcode.SetOpcode64(uval64, byte_order);
653             m_opcode_name.assign(".quad");
654             mnemonic_strm.Printf("0x%16.16" PRIx64, uval64);
655           } break;
656           default:
657             if (inst_size == 0)
658               return;
659             else {
660               const uint8_t *bytes = data.PeekData(offset, inst_size);
661               if (bytes == nullptr)
662                 return;
663               m_opcode_name.assign(".byte");
664               m_opcode.SetOpcodeBytes(bytes, inst_size);
665               mnemonic_strm.Printf("0x%2.2x", bytes[0]);
666               for (uint32_t i = 1; i < inst_size; ++i)
667                 mnemonic_strm.Printf(" 0x%2.2x", bytes[i]);
668             }
669             break;
670           }
671           m_mnemonics = std::string(mnemonic_strm.GetString());
672           return;
673         }
674 
675         static RegularExpression s_regex(
676             llvm::StringRef("[ \t]*([^ ^\t]+)[ \t]*([^ ^\t].*)?"));
677 
678         llvm::SmallVector<llvm::StringRef, 4> matches;
679         if (s_regex.Execute(out_string, &matches)) {
680           m_opcode_name = matches[1].str();
681           m_mnemonics = matches[2].str();
682         }
683         matches.clear();
684         if (s_regex.Execute(markup_out_string, &matches)) {
685           m_markup_opcode_name = matches[1].str();
686           m_markup_mnemonics = matches[2].str();
687         }
688       }
689     }
690   }
691 
692   bool IsValid() const { return m_is_valid; }
693 
694   bool UsingFileAddress() const { return m_using_file_addr; }
695   size_t GetByteSize() const { return m_opcode.GetByteSize(); }
696 
697   /// Grants exclusive access to the disassembler and initializes it with the
698   /// given InstructionLLVMC and an optional ExecutionContext.
699   class DisassemblerScope {
700     std::shared_ptr<DisassemblerLLVMC> m_disasm;
701 
702   public:
703     explicit DisassemblerScope(
704         InstructionLLVMC &i,
705         const lldb_private::ExecutionContext *exe_ctx = nullptr)
706         : m_disasm(i.m_disasm_wp.lock()) {
707       m_disasm->m_mutex.lock();
708       m_disasm->m_inst = &i;
709       m_disasm->m_exe_ctx = exe_ctx;
710     }
711     ~DisassemblerScope() { m_disasm->m_mutex.unlock(); }
712 
713     /// Evaluates to true if this scope contains a valid disassembler.
714     operator bool() const { return static_cast<bool>(m_disasm); }
715 
716     std::shared_ptr<DisassemblerLLVMC> operator->() { return m_disasm; }
717   };
718 
719   static llvm::StringRef::const_iterator
720   ConsumeWhitespace(llvm::StringRef::const_iterator osi,
721                     llvm::StringRef::const_iterator ose) {
722     while (osi != ose) {
723       switch (*osi) {
724       default:
725         return osi;
726       case ' ':
727       case '\t':
728         break;
729       }
730       ++osi;
731     }
732 
733     return osi;
734   }
735 
736   static std::pair<bool, llvm::StringRef::const_iterator>
737   ConsumeChar(llvm::StringRef::const_iterator osi, const char c,
738               llvm::StringRef::const_iterator ose) {
739     bool found = false;
740 
741     osi = ConsumeWhitespace(osi, ose);
742     if (osi != ose && *osi == c) {
743       found = true;
744       ++osi;
745     }
746 
747     return std::make_pair(found, osi);
748   }
749 
750   static std::pair<Operand, llvm::StringRef::const_iterator>
751   ParseRegisterName(llvm::StringRef::const_iterator osi,
752                     llvm::StringRef::const_iterator ose) {
753     Operand ret;
754     ret.m_type = Operand::Type::Register;
755     std::string str;
756 
757     osi = ConsumeWhitespace(osi, ose);
758 
759     while (osi != ose) {
760       if (*osi >= '0' && *osi <= '9') {
761         if (str.empty()) {
762           return std::make_pair(Operand(), osi);
763         } else {
764           str.push_back(*osi);
765         }
766       } else if (*osi >= 'a' && *osi <= 'z') {
767         str.push_back(*osi);
768       } else {
769         switch (*osi) {
770         default:
771           if (str.empty()) {
772             return std::make_pair(Operand(), osi);
773           } else {
774             ret.m_register = ConstString(str);
775             return std::make_pair(ret, osi);
776           }
777         case '%':
778           if (!str.empty()) {
779             return std::make_pair(Operand(), osi);
780           }
781           break;
782         }
783       }
784       ++osi;
785     }
786 
787     ret.m_register = ConstString(str);
788     return std::make_pair(ret, osi);
789   }
790 
791   static std::pair<Operand, llvm::StringRef::const_iterator>
792   ParseImmediate(llvm::StringRef::const_iterator osi,
793                  llvm::StringRef::const_iterator ose) {
794     Operand ret;
795     ret.m_type = Operand::Type::Immediate;
796     std::string str;
797     bool is_hex = false;
798 
799     osi = ConsumeWhitespace(osi, ose);
800 
801     while (osi != ose) {
802       if (*osi >= '0' && *osi <= '9') {
803         str.push_back(*osi);
804       } else if (*osi >= 'a' && *osi <= 'f') {
805         if (is_hex) {
806           str.push_back(*osi);
807         } else {
808           return std::make_pair(Operand(), osi);
809         }
810       } else {
811         switch (*osi) {
812         default:
813           if (str.empty()) {
814             return std::make_pair(Operand(), osi);
815           } else {
816             ret.m_immediate = strtoull(str.c_str(), nullptr, 0);
817             return std::make_pair(ret, osi);
818           }
819         case 'x':
820           if (!str.compare("0")) {
821             is_hex = true;
822             str.push_back(*osi);
823           } else {
824             return std::make_pair(Operand(), osi);
825           }
826           break;
827         case '#':
828         case '$':
829           if (!str.empty()) {
830             return std::make_pair(Operand(), osi);
831           }
832           break;
833         case '-':
834           if (str.empty()) {
835             ret.m_negative = true;
836           } else {
837             return std::make_pair(Operand(), osi);
838           }
839         }
840       }
841       ++osi;
842     }
843 
844     ret.m_immediate = strtoull(str.c_str(), nullptr, 0);
845     return std::make_pair(ret, osi);
846   }
847 
848   // -0x5(%rax,%rax,2)
849   static std::pair<Operand, llvm::StringRef::const_iterator>
850   ParseIntelIndexedAccess(llvm::StringRef::const_iterator osi,
851                           llvm::StringRef::const_iterator ose) {
852     std::pair<Operand, llvm::StringRef::const_iterator> offset_and_iterator =
853         ParseImmediate(osi, ose);
854     if (offset_and_iterator.first.IsValid()) {
855       osi = offset_and_iterator.second;
856     }
857 
858     bool found = false;
859     std::tie(found, osi) = ConsumeChar(osi, '(', ose);
860     if (!found) {
861       return std::make_pair(Operand(), osi);
862     }
863 
864     std::pair<Operand, llvm::StringRef::const_iterator> base_and_iterator =
865         ParseRegisterName(osi, ose);
866     if (base_and_iterator.first.IsValid()) {
867       osi = base_and_iterator.second;
868     } else {
869       return std::make_pair(Operand(), osi);
870     }
871 
872     std::tie(found, osi) = ConsumeChar(osi, ',', ose);
873     if (!found) {
874       return std::make_pair(Operand(), osi);
875     }
876 
877     std::pair<Operand, llvm::StringRef::const_iterator> index_and_iterator =
878         ParseRegisterName(osi, ose);
879     if (index_and_iterator.first.IsValid()) {
880       osi = index_and_iterator.second;
881     } else {
882       return std::make_pair(Operand(), osi);
883     }
884 
885     std::tie(found, osi) = ConsumeChar(osi, ',', ose);
886     if (!found) {
887       return std::make_pair(Operand(), osi);
888     }
889 
890     std::pair<Operand, llvm::StringRef::const_iterator>
891         multiplier_and_iterator = ParseImmediate(osi, ose);
892     if (index_and_iterator.first.IsValid()) {
893       osi = index_and_iterator.second;
894     } else {
895       return std::make_pair(Operand(), osi);
896     }
897 
898     std::tie(found, osi) = ConsumeChar(osi, ')', ose);
899     if (!found) {
900       return std::make_pair(Operand(), osi);
901     }
902 
903     Operand product;
904     product.m_type = Operand::Type::Product;
905     product.m_children.push_back(index_and_iterator.first);
906     product.m_children.push_back(multiplier_and_iterator.first);
907 
908     Operand index;
909     index.m_type = Operand::Type::Sum;
910     index.m_children.push_back(base_and_iterator.first);
911     index.m_children.push_back(product);
912 
913     if (offset_and_iterator.first.IsValid()) {
914       Operand offset;
915       offset.m_type = Operand::Type::Sum;
916       offset.m_children.push_back(offset_and_iterator.first);
917       offset.m_children.push_back(index);
918 
919       Operand deref;
920       deref.m_type = Operand::Type::Dereference;
921       deref.m_children.push_back(offset);
922       return std::make_pair(deref, osi);
923     } else {
924       Operand deref;
925       deref.m_type = Operand::Type::Dereference;
926       deref.m_children.push_back(index);
927       return std::make_pair(deref, osi);
928     }
929   }
930 
931   // -0x10(%rbp)
932   static std::pair<Operand, llvm::StringRef::const_iterator>
933   ParseIntelDerefAccess(llvm::StringRef::const_iterator osi,
934                         llvm::StringRef::const_iterator ose) {
935     std::pair<Operand, llvm::StringRef::const_iterator> offset_and_iterator =
936         ParseImmediate(osi, ose);
937     if (offset_and_iterator.first.IsValid()) {
938       osi = offset_and_iterator.second;
939     }
940 
941     bool found = false;
942     std::tie(found, osi) = ConsumeChar(osi, '(', ose);
943     if (!found) {
944       return std::make_pair(Operand(), osi);
945     }
946 
947     std::pair<Operand, llvm::StringRef::const_iterator> base_and_iterator =
948         ParseRegisterName(osi, ose);
949     if (base_and_iterator.first.IsValid()) {
950       osi = base_and_iterator.second;
951     } else {
952       return std::make_pair(Operand(), osi);
953     }
954 
955     std::tie(found, osi) = ConsumeChar(osi, ')', ose);
956     if (!found) {
957       return std::make_pair(Operand(), osi);
958     }
959 
960     if (offset_and_iterator.first.IsValid()) {
961       Operand offset;
962       offset.m_type = Operand::Type::Sum;
963       offset.m_children.push_back(offset_and_iterator.first);
964       offset.m_children.push_back(base_and_iterator.first);
965 
966       Operand deref;
967       deref.m_type = Operand::Type::Dereference;
968       deref.m_children.push_back(offset);
969       return std::make_pair(deref, osi);
970     } else {
971       Operand deref;
972       deref.m_type = Operand::Type::Dereference;
973       deref.m_children.push_back(base_and_iterator.first);
974       return std::make_pair(deref, osi);
975     }
976   }
977 
978   // [sp, #8]!
979   static std::pair<Operand, llvm::StringRef::const_iterator>
980   ParseARMOffsetAccess(llvm::StringRef::const_iterator osi,
981                        llvm::StringRef::const_iterator ose) {
982     bool found = false;
983     std::tie(found, osi) = ConsumeChar(osi, '[', ose);
984     if (!found) {
985       return std::make_pair(Operand(), osi);
986     }
987 
988     std::pair<Operand, llvm::StringRef::const_iterator> base_and_iterator =
989         ParseRegisterName(osi, ose);
990     if (base_and_iterator.first.IsValid()) {
991       osi = base_and_iterator.second;
992     } else {
993       return std::make_pair(Operand(), osi);
994     }
995 
996     std::tie(found, osi) = ConsumeChar(osi, ',', ose);
997     if (!found) {
998       return std::make_pair(Operand(), osi);
999     }
1000 
1001     std::pair<Operand, llvm::StringRef::const_iterator> offset_and_iterator =
1002         ParseImmediate(osi, ose);
1003     if (offset_and_iterator.first.IsValid()) {
1004       osi = offset_and_iterator.second;
1005     }
1006 
1007     std::tie(found, osi) = ConsumeChar(osi, ']', ose);
1008     if (!found) {
1009       return std::make_pair(Operand(), osi);
1010     }
1011 
1012     Operand offset;
1013     offset.m_type = Operand::Type::Sum;
1014     offset.m_children.push_back(offset_and_iterator.first);
1015     offset.m_children.push_back(base_and_iterator.first);
1016 
1017     Operand deref;
1018     deref.m_type = Operand::Type::Dereference;
1019     deref.m_children.push_back(offset);
1020     return std::make_pair(deref, osi);
1021   }
1022 
1023   // [sp]
1024   static std::pair<Operand, llvm::StringRef::const_iterator>
1025   ParseARMDerefAccess(llvm::StringRef::const_iterator osi,
1026                       llvm::StringRef::const_iterator ose) {
1027     bool found = false;
1028     std::tie(found, osi) = ConsumeChar(osi, '[', ose);
1029     if (!found) {
1030       return std::make_pair(Operand(), osi);
1031     }
1032 
1033     std::pair<Operand, llvm::StringRef::const_iterator> base_and_iterator =
1034         ParseRegisterName(osi, ose);
1035     if (base_and_iterator.first.IsValid()) {
1036       osi = base_and_iterator.second;
1037     } else {
1038       return std::make_pair(Operand(), osi);
1039     }
1040 
1041     std::tie(found, osi) = ConsumeChar(osi, ']', ose);
1042     if (!found) {
1043       return std::make_pair(Operand(), osi);
1044     }
1045 
1046     Operand deref;
1047     deref.m_type = Operand::Type::Dereference;
1048     deref.m_children.push_back(base_and_iterator.first);
1049     return std::make_pair(deref, osi);
1050   }
1051 
1052   static void DumpOperand(const Operand &op, Stream &s) {
1053     switch (op.m_type) {
1054     case Operand::Type::Dereference:
1055       s.PutCString("*");
1056       DumpOperand(op.m_children[0], s);
1057       break;
1058     case Operand::Type::Immediate:
1059       if (op.m_negative) {
1060         s.PutCString("-");
1061       }
1062       s.PutCString(llvm::to_string(op.m_immediate));
1063       break;
1064     case Operand::Type::Invalid:
1065       s.PutCString("Invalid");
1066       break;
1067     case Operand::Type::Product:
1068       s.PutCString("(");
1069       DumpOperand(op.m_children[0], s);
1070       s.PutCString("*");
1071       DumpOperand(op.m_children[1], s);
1072       s.PutCString(")");
1073       break;
1074     case Operand::Type::Register:
1075       s.PutCString(op.m_register.GetStringRef());
1076       break;
1077     case Operand::Type::Sum:
1078       s.PutCString("(");
1079       DumpOperand(op.m_children[0], s);
1080       s.PutCString("+");
1081       DumpOperand(op.m_children[1], s);
1082       s.PutCString(")");
1083       break;
1084     }
1085   }
1086 
1087   bool ParseOperands(
1088       llvm::SmallVectorImpl<Instruction::Operand> &operands) override {
1089     const char *operands_string = GetOperands(nullptr);
1090 
1091     if (!operands_string) {
1092       return false;
1093     }
1094 
1095     llvm::StringRef operands_ref(operands_string);
1096 
1097     llvm::StringRef::const_iterator osi = operands_ref.begin();
1098     llvm::StringRef::const_iterator ose = operands_ref.end();
1099 
1100     while (osi != ose) {
1101       Operand operand;
1102       llvm::StringRef::const_iterator iter;
1103 
1104       if ((std::tie(operand, iter) = ParseIntelIndexedAccess(osi, ose),
1105            operand.IsValid()) ||
1106           (std::tie(operand, iter) = ParseIntelDerefAccess(osi, ose),
1107            operand.IsValid()) ||
1108           (std::tie(operand, iter) = ParseARMOffsetAccess(osi, ose),
1109            operand.IsValid()) ||
1110           (std::tie(operand, iter) = ParseARMDerefAccess(osi, ose),
1111            operand.IsValid()) ||
1112           (std::tie(operand, iter) = ParseRegisterName(osi, ose),
1113            operand.IsValid()) ||
1114           (std::tie(operand, iter) = ParseImmediate(osi, ose),
1115            operand.IsValid())) {
1116         osi = iter;
1117         operands.push_back(operand);
1118       } else {
1119         return false;
1120       }
1121 
1122       std::pair<bool, llvm::StringRef::const_iterator> found_and_iter =
1123           ConsumeChar(osi, ',', ose);
1124       if (found_and_iter.first) {
1125         osi = found_and_iter.second;
1126       }
1127 
1128       osi = ConsumeWhitespace(osi, ose);
1129     }
1130 
1131     DisassemblerSP disasm_sp = m_disasm_wp.lock();
1132 
1133     if (disasm_sp && operands.size() > 1) {
1134       // TODO tie this into the MC Disassembler's notion of clobbers.
1135       switch (disasm_sp->GetArchitecture().GetMachine()) {
1136       default:
1137         break;
1138       case llvm::Triple::x86:
1139       case llvm::Triple::x86_64:
1140         operands[operands.size() - 1].m_clobbered = true;
1141         break;
1142       case llvm::Triple::arm:
1143         operands[0].m_clobbered = true;
1144         break;
1145       }
1146     }
1147 
1148     if (Log *log = GetLog(LLDBLog::Process)) {
1149       StreamString ss;
1150 
1151       ss.Printf("[%s] expands to %zu operands:\n", operands_string,
1152                 operands.size());
1153       for (const Operand &operand : operands) {
1154         ss.PutCString("  ");
1155         DumpOperand(operand, ss);
1156         ss.PutCString("\n");
1157       }
1158 
1159       log->PutString(ss.GetString());
1160     }
1161 
1162     return true;
1163   }
1164 
1165   bool IsCall() override {
1166     VisitInstruction();
1167     return m_is_call;
1168   }
1169 
1170 protected:
1171   std::weak_ptr<DisassemblerLLVMC> m_disasm_wp;
1172 
1173   bool m_is_valid = false;
1174   bool m_using_file_addr = false;
1175   bool m_has_visited_instruction = false;
1176 
1177   // Be conservative. If we didn't understand the instruction, say it:
1178   //   - Might branch
1179   //   - Does not have a delay slot
1180   //   - Is not a call
1181   //   - Is not a load
1182   //   - Is not an authenticated instruction
1183   bool m_does_branch = true;
1184   bool m_has_delay_slot = false;
1185   bool m_is_call = false;
1186   bool m_is_load = false;
1187   bool m_is_authenticated = false;
1188 
1189   void VisitInstruction() {
1190     if (m_has_visited_instruction)
1191       return;
1192 
1193     DisassemblerScope disasm(*this);
1194     if (!disasm)
1195       return;
1196 
1197     DataExtractor data;
1198     if (!m_opcode.GetData(data))
1199       return;
1200 
1201     bool is_alternate_isa;
1202     lldb::addr_t pc = m_address.GetFileAddress();
1203     DisassemblerLLVMC::MCDisasmInstance *mc_disasm_ptr =
1204         GetDisasmToUse(is_alternate_isa, disasm);
1205     const uint8_t *opcode_data = data.GetDataStart();
1206     const size_t opcode_data_len = data.GetByteSize();
1207     llvm::MCInst inst;
1208     const size_t inst_size =
1209         mc_disasm_ptr->GetMCInst(opcode_data, opcode_data_len, pc, inst);
1210     if (inst_size == 0)
1211       return;
1212 
1213     m_has_visited_instruction = true;
1214     m_does_branch = mc_disasm_ptr->CanBranch(inst);
1215     m_has_delay_slot = mc_disasm_ptr->HasDelaySlot(inst);
1216     m_is_call = mc_disasm_ptr->IsCall(inst);
1217     m_is_load = mc_disasm_ptr->IsLoad(inst);
1218     m_is_authenticated = mc_disasm_ptr->IsAuthenticated(inst);
1219   }
1220 
1221 private:
1222   DisassemblerLLVMC::MCDisasmInstance *
1223   GetDisasmToUse(bool &is_alternate_isa, DisassemblerScope &disasm) {
1224     is_alternate_isa = false;
1225     if (disasm) {
1226       if (disasm->m_alternate_disasm_up) {
1227         const AddressClass address_class = GetAddressClass();
1228 
1229         if (address_class == AddressClass::eCodeAlternateISA) {
1230           is_alternate_isa = true;
1231           return disasm->m_alternate_disasm_up.get();
1232         }
1233       }
1234       return disasm->m_disasm_up.get();
1235     }
1236     return nullptr;
1237   }
1238 };
1239 
1240 std::unique_ptr<DisassemblerLLVMC::MCDisasmInstance>
1241 DisassemblerLLVMC::MCDisasmInstance::Create(const char *triple, const char *cpu,
1242                                             const char *features_str,
1243                                             unsigned flavor,
1244                                             DisassemblerLLVMC &owner) {
1245   using Instance = std::unique_ptr<DisassemblerLLVMC::MCDisasmInstance>;
1246 
1247   std::string Status;
1248   const llvm::Target *curr_target =
1249       llvm::TargetRegistry::lookupTarget(triple, Status);
1250   if (!curr_target)
1251     return Instance();
1252 
1253   std::unique_ptr<llvm::MCInstrInfo> instr_info_up(
1254       curr_target->createMCInstrInfo());
1255   if (!instr_info_up)
1256     return Instance();
1257 
1258   std::unique_ptr<llvm::MCRegisterInfo> reg_info_up(
1259       curr_target->createMCRegInfo(triple));
1260   if (!reg_info_up)
1261     return Instance();
1262 
1263   std::unique_ptr<llvm::MCSubtargetInfo> subtarget_info_up(
1264       curr_target->createMCSubtargetInfo(triple, cpu, features_str));
1265   if (!subtarget_info_up)
1266     return Instance();
1267 
1268   llvm::MCTargetOptions MCOptions;
1269   std::unique_ptr<llvm::MCAsmInfo> asm_info_up(
1270       curr_target->createMCAsmInfo(*reg_info_up, triple, MCOptions));
1271   if (!asm_info_up)
1272     return Instance();
1273 
1274   std::unique_ptr<llvm::MCContext> context_up(
1275       new llvm::MCContext(llvm::Triple(triple), asm_info_up.get(),
1276                           reg_info_up.get(), subtarget_info_up.get()));
1277   if (!context_up)
1278     return Instance();
1279 
1280   std::unique_ptr<llvm::MCDisassembler> disasm_up(
1281       curr_target->createMCDisassembler(*subtarget_info_up, *context_up));
1282   if (!disasm_up)
1283     return Instance();
1284 
1285   std::unique_ptr<llvm::MCRelocationInfo> rel_info_up(
1286       curr_target->createMCRelocationInfo(triple, *context_up));
1287   if (!rel_info_up)
1288     return Instance();
1289 
1290   std::unique_ptr<llvm::MCSymbolizer> symbolizer_up(
1291       curr_target->createMCSymbolizer(
1292           triple, nullptr, DisassemblerLLVMC::SymbolLookupCallback, &owner,
1293           context_up.get(), std::move(rel_info_up)));
1294   disasm_up->setSymbolizer(std::move(symbolizer_up));
1295 
1296   unsigned asm_printer_variant =
1297       flavor == ~0U ? asm_info_up->getAssemblerDialect() : flavor;
1298 
1299   std::unique_ptr<llvm::MCInstPrinter> instr_printer_up(
1300       curr_target->createMCInstPrinter(llvm::Triple{triple},
1301                                        asm_printer_variant, *asm_info_up,
1302                                        *instr_info_up, *reg_info_up));
1303   if (!instr_printer_up)
1304     return Instance();
1305 
1306   instr_printer_up->setPrintBranchImmAsAddress(true);
1307 
1308   // Not all targets may have registered createMCInstrAnalysis().
1309   std::unique_ptr<llvm::MCInstrAnalysis> instr_analysis_up(
1310       curr_target->createMCInstrAnalysis(instr_info_up.get()));
1311 
1312   return Instance(new MCDisasmInstance(
1313       std::move(instr_info_up), std::move(reg_info_up),
1314       std::move(subtarget_info_up), std::move(asm_info_up),
1315       std::move(context_up), std::move(disasm_up), std::move(instr_printer_up),
1316       std::move(instr_analysis_up)));
1317 }
1318 
1319 DisassemblerLLVMC::MCDisasmInstance::MCDisasmInstance(
1320     std::unique_ptr<llvm::MCInstrInfo> &&instr_info_up,
1321     std::unique_ptr<llvm::MCRegisterInfo> &&reg_info_up,
1322     std::unique_ptr<llvm::MCSubtargetInfo> &&subtarget_info_up,
1323     std::unique_ptr<llvm::MCAsmInfo> &&asm_info_up,
1324     std::unique_ptr<llvm::MCContext> &&context_up,
1325     std::unique_ptr<llvm::MCDisassembler> &&disasm_up,
1326     std::unique_ptr<llvm::MCInstPrinter> &&instr_printer_up,
1327     std::unique_ptr<llvm::MCInstrAnalysis> &&instr_analysis_up)
1328     : m_instr_info_up(std::move(instr_info_up)),
1329       m_reg_info_up(std::move(reg_info_up)),
1330       m_subtarget_info_up(std::move(subtarget_info_up)),
1331       m_asm_info_up(std::move(asm_info_up)),
1332       m_context_up(std::move(context_up)), m_disasm_up(std::move(disasm_up)),
1333       m_instr_printer_up(std::move(instr_printer_up)),
1334       m_instr_analysis_up(std::move(instr_analysis_up)) {
1335   assert(m_instr_info_up && m_reg_info_up && m_subtarget_info_up &&
1336          m_asm_info_up && m_context_up && m_disasm_up && m_instr_printer_up);
1337 }
1338 
1339 uint64_t DisassemblerLLVMC::MCDisasmInstance::GetMCInst(
1340     const uint8_t *opcode_data, size_t opcode_data_len, lldb::addr_t pc,
1341     llvm::MCInst &mc_inst) const {
1342   llvm::ArrayRef<uint8_t> data(opcode_data, opcode_data_len);
1343   llvm::MCDisassembler::DecodeStatus status;
1344 
1345   uint64_t new_inst_size;
1346   status = m_disasm_up->getInstruction(mc_inst, new_inst_size, data, pc,
1347                                        llvm::nulls());
1348   if (status == llvm::MCDisassembler::Success)
1349     return new_inst_size;
1350   else
1351     return 0;
1352 }
1353 
1354 void DisassemblerLLVMC::MCDisasmInstance::PrintMCInst(
1355     llvm::MCInst &mc_inst, lldb::addr_t pc, std::string &inst_string,
1356     std::string &comments_string) {
1357   llvm::raw_string_ostream inst_stream(inst_string);
1358   llvm::raw_string_ostream comments_stream(comments_string);
1359 
1360   inst_stream.enable_colors(m_instr_printer_up->getUseColor());
1361   m_instr_printer_up->setCommentStream(comments_stream);
1362   m_instr_printer_up->printInst(&mc_inst, pc, llvm::StringRef(),
1363                                 *m_subtarget_info_up, inst_stream);
1364   m_instr_printer_up->setCommentStream(llvm::nulls());
1365 
1366   static std::string g_newlines("\r\n");
1367 
1368   for (size_t newline_pos = 0;
1369        (newline_pos = comments_string.find_first_of(g_newlines, newline_pos)) !=
1370        comments_string.npos;
1371        /**/) {
1372     comments_string.replace(comments_string.begin() + newline_pos,
1373                             comments_string.begin() + newline_pos + 1, 1, ' ');
1374   }
1375 }
1376 
1377 void DisassemblerLLVMC::MCDisasmInstance::SetStyle(
1378     bool use_hex_immed, HexImmediateStyle hex_style) {
1379   m_instr_printer_up->setPrintImmHex(use_hex_immed);
1380   switch (hex_style) {
1381   case eHexStyleC:
1382     m_instr_printer_up->setPrintHexStyle(llvm::HexStyle::C);
1383     break;
1384   case eHexStyleAsm:
1385     m_instr_printer_up->setPrintHexStyle(llvm::HexStyle::Asm);
1386     break;
1387   }
1388 }
1389 
1390 void DisassemblerLLVMC::MCDisasmInstance::SetUseColor(bool use_color) {
1391   m_instr_printer_up->setUseColor(use_color);
1392 }
1393 
1394 bool DisassemblerLLVMC::MCDisasmInstance::GetUseColor() const {
1395   return m_instr_printer_up->getUseColor();
1396 }
1397 
1398 bool DisassemblerLLVMC::MCDisasmInstance::CanBranch(
1399     llvm::MCInst &mc_inst) const {
1400   if (m_instr_analysis_up)
1401     return m_instr_analysis_up->mayAffectControlFlow(mc_inst, *m_reg_info_up);
1402   return m_instr_info_up->get(mc_inst.getOpcode())
1403       .mayAffectControlFlow(mc_inst, *m_reg_info_up);
1404 }
1405 
1406 bool DisassemblerLLVMC::MCDisasmInstance::HasDelaySlot(
1407     llvm::MCInst &mc_inst) const {
1408   return m_instr_info_up->get(mc_inst.getOpcode()).hasDelaySlot();
1409 }
1410 
1411 bool DisassemblerLLVMC::MCDisasmInstance::IsCall(llvm::MCInst &mc_inst) const {
1412   if (m_instr_analysis_up)
1413     return m_instr_analysis_up->isCall(mc_inst);
1414   return m_instr_info_up->get(mc_inst.getOpcode()).isCall();
1415 }
1416 
1417 bool DisassemblerLLVMC::MCDisasmInstance::IsLoad(llvm::MCInst &mc_inst) const {
1418   return m_instr_info_up->get(mc_inst.getOpcode()).mayLoad();
1419 }
1420 
1421 bool DisassemblerLLVMC::MCDisasmInstance::IsAuthenticated(
1422     llvm::MCInst &mc_inst) const {
1423   const auto &InstrDesc = m_instr_info_up->get(mc_inst.getOpcode());
1424 
1425   // Treat software auth traps (brk 0xc470 + aut key, where 0x70 == 'p', 0xc4
1426   // == 'a' + 'c') as authenticated instructions for reporting purposes, in
1427   // addition to the standard authenticated instructions specified in ARMv8.3.
1428   bool IsBrkC47x = false;
1429   if (InstrDesc.isTrap() && mc_inst.getNumOperands() == 1) {
1430     const llvm::MCOperand &Op0 = mc_inst.getOperand(0);
1431     if (Op0.isImm() && Op0.getImm() >= 0xc470 && Op0.getImm() <= 0xc474)
1432       IsBrkC47x = true;
1433   }
1434 
1435   return InstrDesc.isAuthenticated() || IsBrkC47x;
1436 }
1437 
1438 DisassemblerLLVMC::DisassemblerLLVMC(const ArchSpec &arch,
1439                                      const char *flavor_string,
1440                                      const char *cpu_string,
1441                                      const char *features_string)
1442     : Disassembler(arch, flavor_string), m_exe_ctx(nullptr), m_inst(nullptr),
1443       m_data_from_file(false), m_adrp_address(LLDB_INVALID_ADDRESS),
1444       m_adrp_insn() {
1445   if (!FlavorValidForArchSpec(arch, m_flavor.c_str())) {
1446     m_flavor.assign("default");
1447   }
1448 
1449   const bool cpu_or_features_overriden = cpu_string || features_string;
1450   unsigned flavor = ~0U;
1451   llvm::Triple triple = arch.GetTriple();
1452 
1453   // So far the only supported flavor is "intel" on x86.  The base class will
1454   // set this correctly coming in.
1455   if (triple.getArch() == llvm::Triple::x86 ||
1456       triple.getArch() == llvm::Triple::x86_64) {
1457     if (m_flavor == "intel") {
1458       flavor = 1;
1459     } else if (m_flavor == "att") {
1460       flavor = 0;
1461     }
1462   }
1463 
1464   ArchSpec thumb_arch(arch);
1465   if (triple.getArch() == llvm::Triple::arm) {
1466     std::string thumb_arch_name(thumb_arch.GetTriple().getArchName().str());
1467     // Replace "arm" with "thumb" so we get all thumb variants correct
1468     if (thumb_arch_name.size() > 3) {
1469       thumb_arch_name.erase(0, 3);
1470       thumb_arch_name.insert(0, "thumb");
1471     } else {
1472       thumb_arch_name = "thumbv9.3a";
1473     }
1474     thumb_arch.GetTriple().setArchName(llvm::StringRef(thumb_arch_name));
1475   }
1476 
1477   // If no sub architecture specified then use the most recent arm architecture
1478   // so the disassembler will return all instructions. Without it we will see a
1479   // lot of unknown opcodes if the code uses instructions which are not
1480   // available in the oldest arm version (which is used when no sub architecture
1481   // is specified).
1482   if (triple.getArch() == llvm::Triple::arm &&
1483       triple.getSubArch() == llvm::Triple::NoSubArch)
1484     triple.setArchName("armv9.3a");
1485 
1486   std::string features_str =
1487       features_string ? std::string(features_string) : "";
1488   const char *triple_str = triple.getTriple().c_str();
1489 
1490   // ARM Cortex M0-M7 devices only execute thumb instructions
1491   if (arch.IsAlwaysThumbInstructions()) {
1492     triple_str = thumb_arch.GetTriple().getTriple().c_str();
1493     if (!features_string)
1494       features_str += "+fp-armv8,";
1495   }
1496 
1497   const char *cpu = cpu_string;
1498 
1499   if (!cpu_or_features_overriden) {
1500     switch (arch.GetCore()) {
1501     case ArchSpec::eCore_mips32:
1502     case ArchSpec::eCore_mips32el:
1503       cpu = "mips32";
1504       break;
1505     case ArchSpec::eCore_mips32r2:
1506     case ArchSpec::eCore_mips32r2el:
1507       cpu = "mips32r2";
1508       break;
1509     case ArchSpec::eCore_mips32r3:
1510     case ArchSpec::eCore_mips32r3el:
1511       cpu = "mips32r3";
1512       break;
1513     case ArchSpec::eCore_mips32r5:
1514     case ArchSpec::eCore_mips32r5el:
1515       cpu = "mips32r5";
1516       break;
1517     case ArchSpec::eCore_mips32r6:
1518     case ArchSpec::eCore_mips32r6el:
1519       cpu = "mips32r6";
1520       break;
1521     case ArchSpec::eCore_mips64:
1522     case ArchSpec::eCore_mips64el:
1523       cpu = "mips64";
1524       break;
1525     case ArchSpec::eCore_mips64r2:
1526     case ArchSpec::eCore_mips64r2el:
1527       cpu = "mips64r2";
1528       break;
1529     case ArchSpec::eCore_mips64r3:
1530     case ArchSpec::eCore_mips64r3el:
1531       cpu = "mips64r3";
1532       break;
1533     case ArchSpec::eCore_mips64r5:
1534     case ArchSpec::eCore_mips64r5el:
1535       cpu = "mips64r5";
1536       break;
1537     case ArchSpec::eCore_mips64r6:
1538     case ArchSpec::eCore_mips64r6el:
1539       cpu = "mips64r6";
1540       break;
1541     default:
1542       cpu = "";
1543       break;
1544     }
1545   }
1546 
1547   if (arch.IsMIPS() && !cpu_or_features_overriden) {
1548     uint32_t arch_flags = arch.GetFlags();
1549     if (arch_flags & ArchSpec::eMIPSAse_msa)
1550       features_str += "+msa,";
1551     if (arch_flags & ArchSpec::eMIPSAse_dsp)
1552       features_str += "+dsp,";
1553     if (arch_flags & ArchSpec::eMIPSAse_dspr2)
1554       features_str += "+dspr2,";
1555   }
1556 
1557   // If any AArch64 variant, enable latest ISA with all extensions unless the
1558   // CPU or features were overridden.
1559   if (triple.isAArch64() && !cpu_or_features_overriden) {
1560     features_str += "+all,";
1561     if (triple.getVendor() == llvm::Triple::Apple)
1562       cpu = "apple-latest";
1563   }
1564 
1565   if (triple.isRISCV() && !cpu_or_features_overriden) {
1566     uint32_t arch_flags = arch.GetFlags();
1567     if (arch_flags & ArchSpec::eRISCV_rvc)
1568       features_str += "+c,";
1569     if (arch_flags & ArchSpec::eRISCV_rve)
1570       features_str += "+e,";
1571     if ((arch_flags & ArchSpec::eRISCV_float_abi_single) ==
1572         ArchSpec::eRISCV_float_abi_single)
1573       features_str += "+f,";
1574     if ((arch_flags & ArchSpec::eRISCV_float_abi_double) ==
1575         ArchSpec::eRISCV_float_abi_double)
1576       features_str += "+f,+d,";
1577     if ((arch_flags & ArchSpec::eRISCV_float_abi_quad) ==
1578         ArchSpec::eRISCV_float_abi_quad)
1579       features_str += "+f,+d,+q,";
1580     // FIXME: how do we detect features such as `+a`, `+m`?
1581     // Turn them on by default now, since everyone seems to use them
1582     features_str += "+a,+m,";
1583   }
1584 
1585   // We use m_disasm_up.get() to tell whether we are valid or not, so if this
1586   // isn't good for some reason, we won't be valid and FindPlugin will fail and
1587   // we won't get used.
1588   m_disasm_up = MCDisasmInstance::Create(triple_str, cpu, features_str.c_str(),
1589                                          flavor, *this);
1590 
1591   llvm::Triple::ArchType llvm_arch = triple.getArch();
1592 
1593   // For arm CPUs that can execute arm or thumb instructions, also create a
1594   // thumb instruction disassembler.
1595   if (llvm_arch == llvm::Triple::arm) {
1596     std::string thumb_triple(thumb_arch.GetTriple().getTriple());
1597     m_alternate_disasm_up =
1598         MCDisasmInstance::Create(thumb_triple.c_str(), "", features_str.c_str(),
1599                                  flavor, *this);
1600     if (!m_alternate_disasm_up)
1601       m_disasm_up.reset();
1602 
1603   } else if (arch.IsMIPS()) {
1604     /* Create alternate disassembler for MIPS16 and microMIPS */
1605     uint32_t arch_flags = arch.GetFlags();
1606     if (arch_flags & ArchSpec::eMIPSAse_mips16)
1607       features_str += "+mips16,";
1608     else if (arch_flags & ArchSpec::eMIPSAse_micromips)
1609       features_str += "+micromips,";
1610 
1611     m_alternate_disasm_up = MCDisasmInstance::Create(
1612         triple_str, cpu, features_str.c_str(), flavor, *this);
1613     if (!m_alternate_disasm_up)
1614       m_disasm_up.reset();
1615   }
1616 }
1617 
1618 DisassemblerLLVMC::~DisassemblerLLVMC() = default;
1619 
1620 lldb::DisassemblerSP DisassemblerLLVMC::CreateInstance(const ArchSpec &arch,
1621                                                        const char *flavor,
1622                                                        const char *cpu,
1623                                                        const char *features) {
1624   if (arch.GetTriple().getArch() != llvm::Triple::UnknownArch) {
1625     auto disasm_sp =
1626         std::make_shared<DisassemblerLLVMC>(arch, flavor, cpu, features);
1627     if (disasm_sp && disasm_sp->IsValid())
1628       return disasm_sp;
1629   }
1630   return lldb::DisassemblerSP();
1631 }
1632 
1633 size_t DisassemblerLLVMC::DecodeInstructions(const Address &base_addr,
1634                                              const DataExtractor &data,
1635                                              lldb::offset_t data_offset,
1636                                              size_t num_instructions,
1637                                              bool append, bool data_from_file) {
1638   if (!append)
1639     m_instruction_list.Clear();
1640 
1641   if (!IsValid())
1642     return 0;
1643 
1644   m_data_from_file = data_from_file;
1645   uint32_t data_cursor = data_offset;
1646   const size_t data_byte_size = data.GetByteSize();
1647   uint32_t instructions_parsed = 0;
1648   Address inst_addr(base_addr);
1649 
1650   while (data_cursor < data_byte_size &&
1651          instructions_parsed < num_instructions) {
1652 
1653     AddressClass address_class = AddressClass::eCode;
1654 
1655     if (m_alternate_disasm_up)
1656       address_class = inst_addr.GetAddressClass();
1657 
1658     InstructionSP inst_sp(
1659         new InstructionLLVMC(*this, inst_addr, address_class));
1660 
1661     if (!inst_sp)
1662       break;
1663 
1664     uint32_t inst_size = inst_sp->Decode(*this, data, data_cursor);
1665 
1666     if (inst_size == 0)
1667       break;
1668 
1669     m_instruction_list.Append(inst_sp);
1670     data_cursor += inst_size;
1671     inst_addr.Slide(inst_size);
1672     instructions_parsed++;
1673   }
1674 
1675   return data_cursor - data_offset;
1676 }
1677 
1678 void DisassemblerLLVMC::Initialize() {
1679   PluginManager::RegisterPlugin(GetPluginNameStatic(),
1680                                 "Disassembler that uses LLVM MC to disassemble "
1681                                 "i386, x86_64, ARM, and ARM64.",
1682                                 CreateInstance);
1683 
1684   llvm::InitializeAllTargetInfos();
1685   llvm::InitializeAllTargetMCs();
1686   llvm::InitializeAllAsmParsers();
1687   llvm::InitializeAllDisassemblers();
1688 }
1689 
1690 void DisassemblerLLVMC::Terminate() {
1691   PluginManager::UnregisterPlugin(CreateInstance);
1692 }
1693 
1694 int DisassemblerLLVMC::OpInfoCallback(void *disassembler, uint64_t pc,
1695                                       uint64_t offset, uint64_t size,
1696                                       int tag_type, void *tag_bug) {
1697   return static_cast<DisassemblerLLVMC *>(disassembler)
1698       ->OpInfo(pc, offset, size, tag_type, tag_bug);
1699 }
1700 
1701 const char *DisassemblerLLVMC::SymbolLookupCallback(void *disassembler,
1702                                                     uint64_t value,
1703                                                     uint64_t *type, uint64_t pc,
1704                                                     const char **name) {
1705   return static_cast<DisassemblerLLVMC *>(disassembler)
1706       ->SymbolLookup(value, type, pc, name);
1707 }
1708 
1709 bool DisassemblerLLVMC::FlavorValidForArchSpec(
1710     const lldb_private::ArchSpec &arch, const char *flavor) {
1711   llvm::Triple triple = arch.GetTriple();
1712   if (flavor == nullptr || strcmp(flavor, "default") == 0)
1713     return true;
1714 
1715   if (triple.getArch() == llvm::Triple::x86 ||
1716       triple.getArch() == llvm::Triple::x86_64) {
1717     return strcmp(flavor, "intel") == 0 || strcmp(flavor, "att") == 0;
1718   } else
1719     return false;
1720 }
1721 
1722 bool DisassemblerLLVMC::IsValid() const { return m_disasm_up.operator bool(); }
1723 
1724 int DisassemblerLLVMC::OpInfo(uint64_t PC, uint64_t Offset, uint64_t Size,
1725                               int tag_type, void *tag_bug) {
1726   switch (tag_type) {
1727   default:
1728     break;
1729   case 1:
1730     memset(tag_bug, 0, sizeof(::LLVMOpInfo1));
1731     break;
1732   }
1733   return 0;
1734 }
1735 
1736 const char *DisassemblerLLVMC::SymbolLookup(uint64_t value, uint64_t *type_ptr,
1737                                             uint64_t pc, const char **name) {
1738   if (*type_ptr) {
1739     if (m_exe_ctx && m_inst) {
1740       // std::string remove_this_prior_to_checkin;
1741       Target *target = m_exe_ctx ? m_exe_ctx->GetTargetPtr() : nullptr;
1742       Address value_so_addr;
1743       Address pc_so_addr;
1744       if (target->GetArchitecture().GetMachine() == llvm::Triple::aarch64 ||
1745           target->GetArchitecture().GetMachine() == llvm::Triple::aarch64_be ||
1746           target->GetArchitecture().GetMachine() == llvm::Triple::aarch64_32) {
1747         if (*type_ptr == LLVMDisassembler_ReferenceType_In_ARM64_ADRP) {
1748           m_adrp_address = pc;
1749           m_adrp_insn = value;
1750           *name = nullptr;
1751           *type_ptr = LLVMDisassembler_ReferenceType_InOut_None;
1752           return nullptr;
1753         }
1754         // If this instruction is an ADD and
1755         // the previous instruction was an ADRP and
1756         // the ADRP's register and this ADD's register are the same,
1757         // then this is a pc-relative address calculation.
1758         if (*type_ptr == LLVMDisassembler_ReferenceType_In_ARM64_ADDXri &&
1759             m_adrp_insn && m_adrp_address == pc - 4 &&
1760             (*m_adrp_insn & 0x1f) == ((value >> 5) & 0x1f)) {
1761           uint32_t addxri_inst;
1762           uint64_t adrp_imm, addxri_imm;
1763           // Get immlo and immhi bits, OR them together to get the ADRP imm
1764           // value.
1765           adrp_imm =
1766               ((*m_adrp_insn & 0x00ffffe0) >> 3) | ((*m_adrp_insn >> 29) & 0x3);
1767           // if high bit of immhi after right-shifting set, sign extend
1768           if (adrp_imm & (1ULL << 20))
1769             adrp_imm |= ~((1ULL << 21) - 1);
1770 
1771           addxri_inst = value;
1772           addxri_imm = (addxri_inst >> 10) & 0xfff;
1773           // check if 'sh' bit is set, shift imm value up if so
1774           // (this would make no sense, ADRP already gave us this part)
1775           if ((addxri_inst >> (12 + 5 + 5)) & 1)
1776             addxri_imm <<= 12;
1777           value = (m_adrp_address & 0xfffffffffffff000LL) + (adrp_imm << 12) +
1778                   addxri_imm;
1779         }
1780         m_adrp_address = LLDB_INVALID_ADDRESS;
1781         m_adrp_insn.reset();
1782       }
1783 
1784       if (m_inst->UsingFileAddress()) {
1785         ModuleSP module_sp(m_inst->GetAddress().GetModule());
1786         if (module_sp) {
1787           module_sp->ResolveFileAddress(value, value_so_addr);
1788           module_sp->ResolveFileAddress(pc, pc_so_addr);
1789         }
1790       } else if (target && target->HasLoadedSections()) {
1791         target->ResolveLoadAddress(value, value_so_addr);
1792         target->ResolveLoadAddress(pc, pc_so_addr);
1793       }
1794 
1795       SymbolContext sym_ctx;
1796       const SymbolContextItem resolve_scope =
1797           eSymbolContextFunction | eSymbolContextSymbol;
1798       if (pc_so_addr.IsValid() && pc_so_addr.GetModule()) {
1799         pc_so_addr.GetModule()->ResolveSymbolContextForAddress(
1800             pc_so_addr, resolve_scope, sym_ctx);
1801       }
1802 
1803       if (value_so_addr.IsValid() && value_so_addr.GetSection()) {
1804         StreamString ss;
1805 
1806         bool format_omitting_current_func_name = false;
1807         if (sym_ctx.symbol || sym_ctx.function) {
1808           AddressRange range;
1809           if (sym_ctx.GetAddressRange(resolve_scope, 0, false, range) &&
1810               range.GetBaseAddress().IsValid() &&
1811               range.ContainsLoadAddress(value_so_addr, target)) {
1812             format_omitting_current_func_name = true;
1813           }
1814         }
1815 
1816         // If the "value" address (the target address we're symbolicating) is
1817         // inside the same SymbolContext as the current instruction pc
1818         // (pc_so_addr), don't print the full function name - just print it
1819         // with DumpStyleNoFunctionName style, e.g. "<+36>".
1820         if (format_omitting_current_func_name) {
1821           value_so_addr.Dump(&ss, target, Address::DumpStyleNoFunctionName,
1822                              Address::DumpStyleSectionNameOffset);
1823         } else {
1824           value_so_addr.Dump(
1825               &ss, target,
1826               Address::DumpStyleResolvedDescriptionNoFunctionArguments,
1827               Address::DumpStyleSectionNameOffset);
1828         }
1829 
1830         if (!ss.GetString().empty()) {
1831           // If Address::Dump returned a multi-line description, most commonly
1832           // seen when we have multiple levels of inlined functions at an
1833           // address, only show the first line.
1834           std::string str = std::string(ss.GetString());
1835           size_t first_eol_char = str.find_first_of("\r\n");
1836           if (first_eol_char != std::string::npos) {
1837             str.erase(first_eol_char);
1838           }
1839           m_inst->AppendComment(str);
1840         }
1841       }
1842     }
1843   }
1844 
1845   // TODO: llvm-objdump sets the type_ptr to the
1846   // LLVMDisassembler_ReferenceType_Out_* values
1847   // based on where value_so_addr is pointing, with
1848   // Mach-O specific augmentations in MachODump.cpp. e.g.
1849   // see what AArch64ExternalSymbolizer::tryAddingSymbolicOperand
1850   // handles.
1851   *type_ptr = LLVMDisassembler_ReferenceType_InOut_None;
1852   *name = nullptr;
1853   return nullptr;
1854 }
1855