xref: /llvm-project/lldb/source/Commands/CommandObjectDisassemble.cpp (revision 7ced9fff95473c1794b51a3cfd099b4fea3d1a58)
1 //===-- CommandObjectDisassemble.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 "CommandObjectDisassemble.h"
10 #include "lldb/Core/AddressRange.h"
11 #include "lldb/Core/Disassembler.h"
12 #include "lldb/Core/Module.h"
13 #include "lldb/Host/OptionParser.h"
14 #include "lldb/Interpreter/CommandInterpreter.h"
15 #include "lldb/Interpreter/CommandOptionArgumentTable.h"
16 #include "lldb/Interpreter/CommandReturnObject.h"
17 #include "lldb/Interpreter/OptionArgParser.h"
18 #include "lldb/Interpreter/Options.h"
19 #include "lldb/Symbol/Function.h"
20 #include "lldb/Symbol/Symbol.h"
21 #include "lldb/Target/SectionLoadList.h"
22 #include "lldb/Target/StackFrame.h"
23 #include "lldb/Target/Target.h"
24 
25 static constexpr unsigned default_disasm_byte_size = 32;
26 static constexpr unsigned default_disasm_num_ins = 4;
27 
28 using namespace lldb;
29 using namespace lldb_private;
30 
31 #define LLDB_OPTIONS_disassemble
32 #include "CommandOptions.inc"
33 
34 CommandObjectDisassemble::CommandOptions::CommandOptions() {
35   OptionParsingStarting(nullptr);
36 }
37 
38 CommandObjectDisassemble::CommandOptions::~CommandOptions() = default;
39 
40 Status CommandObjectDisassemble::CommandOptions::SetOptionValue(
41     uint32_t option_idx, llvm::StringRef option_arg,
42     ExecutionContext *execution_context) {
43   Status error;
44 
45   const int short_option = m_getopt_table[option_idx].val;
46 
47   switch (short_option) {
48   case 'm':
49     show_mixed = true;
50     break;
51 
52   case 'C':
53     if (option_arg.getAsInteger(0, num_lines_context))
54       error.SetErrorStringWithFormat("invalid num context lines string: \"%s\"",
55                                      option_arg.str().c_str());
56     break;
57 
58   case 'c':
59     if (option_arg.getAsInteger(0, num_instructions))
60       error.SetErrorStringWithFormat(
61           "invalid num of instructions string: \"%s\"",
62           option_arg.str().c_str());
63     break;
64 
65   case 'b':
66     show_bytes = true;
67     break;
68 
69   case 'k':
70     show_control_flow_kind = true;
71     break;
72 
73   case 's': {
74     start_addr = OptionArgParser::ToAddress(execution_context, option_arg,
75                                             LLDB_INVALID_ADDRESS, &error);
76     if (start_addr != LLDB_INVALID_ADDRESS)
77       some_location_specified = true;
78   } break;
79   case 'e': {
80     end_addr = OptionArgParser::ToAddress(execution_context, option_arg,
81                                           LLDB_INVALID_ADDRESS, &error);
82     if (end_addr != LLDB_INVALID_ADDRESS)
83       some_location_specified = true;
84   } break;
85 
86   case 'n':
87     func_name.assign(std::string(option_arg));
88     some_location_specified = true;
89     break;
90 
91   case 'p':
92     at_pc = true;
93     some_location_specified = true;
94     break;
95 
96   case 'l':
97     frame_line = true;
98     // Disassemble the current source line kind of implies showing mixed source
99     // code context.
100     show_mixed = true;
101     some_location_specified = true;
102     break;
103 
104   case 'P':
105     plugin_name.assign(std::string(option_arg));
106     break;
107 
108   case 'F': {
109     TargetSP target_sp =
110         execution_context ? execution_context->GetTargetSP() : TargetSP();
111     if (target_sp && (target_sp->GetArchitecture().GetTriple().getArch() ==
112                           llvm::Triple::x86 ||
113                       target_sp->GetArchitecture().GetTriple().getArch() ==
114                           llvm::Triple::x86_64)) {
115       flavor_string.assign(std::string(option_arg));
116     } else
117       error.SetErrorStringWithFormat("Disassembler flavors are currently only "
118                                      "supported for x86 and x86_64 targets.");
119     break;
120   }
121 
122   case 'r':
123     raw = true;
124     break;
125 
126   case 'f':
127     current_function = true;
128     some_location_specified = true;
129     break;
130 
131   case 'A':
132     if (execution_context) {
133       const auto &target_sp = execution_context->GetTargetSP();
134       auto platform_ptr = target_sp ? target_sp->GetPlatform().get() : nullptr;
135       arch = Platform::GetAugmentedArchSpec(platform_ptr, option_arg);
136     }
137     break;
138 
139   case 'a': {
140     symbol_containing_addr = OptionArgParser::ToAddress(
141         execution_context, option_arg, LLDB_INVALID_ADDRESS, &error);
142     if (symbol_containing_addr != LLDB_INVALID_ADDRESS) {
143       some_location_specified = true;
144     }
145   } break;
146 
147   case '\x01':
148     force = true;
149     break;
150 
151   default:
152     llvm_unreachable("Unimplemented option");
153   }
154 
155   return error;
156 }
157 
158 void CommandObjectDisassemble::CommandOptions::OptionParsingStarting(
159     ExecutionContext *execution_context) {
160   show_mixed = false;
161   show_bytes = false;
162   show_control_flow_kind = false;
163   num_lines_context = 0;
164   num_instructions = 0;
165   func_name.clear();
166   current_function = false;
167   at_pc = false;
168   frame_line = false;
169   start_addr = LLDB_INVALID_ADDRESS;
170   end_addr = LLDB_INVALID_ADDRESS;
171   symbol_containing_addr = LLDB_INVALID_ADDRESS;
172   raw = false;
173   plugin_name.clear();
174 
175   Target *target =
176       execution_context ? execution_context->GetTargetPtr() : nullptr;
177 
178   // This is a hack till we get the ability to specify features based on
179   // architecture.  For now GetDisassemblyFlavor is really only valid for x86
180   // (and for the llvm assembler plugin, but I'm papering over that since that
181   // is the only disassembler plugin we have...
182   if (target) {
183     if (target->GetArchitecture().GetTriple().getArch() == llvm::Triple::x86 ||
184         target->GetArchitecture().GetTriple().getArch() ==
185             llvm::Triple::x86_64) {
186       flavor_string.assign(target->GetDisassemblyFlavor());
187     } else
188       flavor_string.assign("default");
189 
190   } else
191     flavor_string.assign("default");
192 
193   arch.Clear();
194   some_location_specified = false;
195   force = false;
196 }
197 
198 Status CommandObjectDisassemble::CommandOptions::OptionParsingFinished(
199     ExecutionContext *execution_context) {
200   if (!some_location_specified)
201     current_function = true;
202   return Status();
203 }
204 
205 llvm::ArrayRef<OptionDefinition>
206 CommandObjectDisassemble::CommandOptions::GetDefinitions() {
207   return llvm::makeArrayRef(g_disassemble_options);
208 }
209 
210 // CommandObjectDisassemble
211 
212 CommandObjectDisassemble::CommandObjectDisassemble(
213     CommandInterpreter &interpreter)
214     : CommandObjectParsed(
215           interpreter, "disassemble",
216           "Disassemble specified instructions in the current target.  "
217           "Defaults to the current function for the current thread and "
218           "stack frame.",
219           "disassemble [<cmd-options>]", eCommandRequiresTarget),
220       m_options() {}
221 
222 CommandObjectDisassemble::~CommandObjectDisassemble() = default;
223 
224 llvm::Error CommandObjectDisassemble::CheckRangeSize(const AddressRange &range,
225                                                      llvm::StringRef what) {
226   if (m_options.num_instructions > 0 || m_options.force ||
227       range.GetByteSize() < GetDebugger().GetStopDisassemblyMaxSize())
228     return llvm::Error::success();
229   StreamString msg;
230   msg << "Not disassembling " << what << " because it is very large ";
231   range.Dump(&msg, &GetSelectedTarget(), Address::DumpStyleLoadAddress,
232              Address::DumpStyleFileAddress);
233   msg << ". To disassemble specify an instruction count limit, start/stop "
234          "addresses or use the --force option.";
235   return llvm::createStringError(llvm::inconvertibleErrorCode(),
236                                  msg.GetString());
237 }
238 
239 llvm::Expected<std::vector<AddressRange>>
240 CommandObjectDisassemble::GetContainingAddressRanges() {
241   std::vector<AddressRange> ranges;
242   const auto &get_range = [&](Address addr) {
243     ModuleSP module_sp(addr.GetModule());
244     SymbolContext sc;
245     bool resolve_tail_call_address = true;
246     addr.GetModule()->ResolveSymbolContextForAddress(
247         addr, eSymbolContextEverything, sc, resolve_tail_call_address);
248     if (sc.function || sc.symbol) {
249       AddressRange range;
250       sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0,
251                          false, range);
252       ranges.push_back(range);
253     }
254   };
255 
256   Target &target = GetSelectedTarget();
257   if (!target.GetSectionLoadList().IsEmpty()) {
258     Address symbol_containing_address;
259     if (target.GetSectionLoadList().ResolveLoadAddress(
260             m_options.symbol_containing_addr, symbol_containing_address)) {
261       get_range(symbol_containing_address);
262     }
263   } else {
264     for (lldb::ModuleSP module_sp : target.GetImages().Modules()) {
265       Address file_address;
266       if (module_sp->ResolveFileAddress(m_options.symbol_containing_addr,
267                                         file_address)) {
268         get_range(file_address);
269       }
270     }
271   }
272 
273   if (ranges.empty()) {
274     return llvm::createStringError(
275         llvm::inconvertibleErrorCode(),
276         "Could not find function bounds for address 0x%" PRIx64,
277         m_options.symbol_containing_addr);
278   }
279 
280   if (llvm::Error err = CheckRangeSize(ranges[0], "the function"))
281     return std::move(err);
282   return ranges;
283 }
284 
285 llvm::Expected<std::vector<AddressRange>>
286 CommandObjectDisassemble::GetCurrentFunctionRanges() {
287   Process *process = m_exe_ctx.GetProcessPtr();
288   StackFrame *frame = m_exe_ctx.GetFramePtr();
289   if (!frame) {
290     if (process) {
291       return llvm::createStringError(
292           llvm::inconvertibleErrorCode(),
293           "Cannot disassemble around the current "
294           "function without the process being stopped.\n");
295     } else {
296       return llvm::createStringError(llvm::inconvertibleErrorCode(),
297                                      "Cannot disassemble around the current "
298                                      "function without a selected frame: "
299                                      "no currently running process.\n");
300     }
301   }
302   SymbolContext sc(
303       frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
304   AddressRange range;
305   if (sc.function)
306     range = sc.function->GetAddressRange();
307   else if (sc.symbol && sc.symbol->ValueIsAddress()) {
308     range = {sc.symbol->GetAddress(), sc.symbol->GetByteSize()};
309   } else
310     range = {frame->GetFrameCodeAddress(), default_disasm_byte_size};
311 
312   if (llvm::Error err = CheckRangeSize(range, "the current function"))
313     return std::move(err);
314   return std::vector<AddressRange>{range};
315 }
316 
317 llvm::Expected<std::vector<AddressRange>>
318 CommandObjectDisassemble::GetCurrentLineRanges() {
319   Process *process = m_exe_ctx.GetProcessPtr();
320   StackFrame *frame = m_exe_ctx.GetFramePtr();
321   if (!frame) {
322     if (process) {
323       return llvm::createStringError(
324           llvm::inconvertibleErrorCode(),
325           "Cannot disassemble around the current "
326           "function without the process being stopped.\n");
327     } else {
328       return llvm::createStringError(llvm::inconvertibleErrorCode(),
329                                      "Cannot disassemble around the current "
330                                      "line without a selected frame: "
331                                      "no currently running process.\n");
332     }
333   }
334 
335   LineEntry pc_line_entry(
336       frame->GetSymbolContext(eSymbolContextLineEntry).line_entry);
337   if (pc_line_entry.IsValid())
338     return std::vector<AddressRange>{pc_line_entry.range};
339 
340   // No line entry, so just disassemble around the current pc
341   m_options.show_mixed = false;
342   return GetPCRanges();
343 }
344 
345 llvm::Expected<std::vector<AddressRange>>
346 CommandObjectDisassemble::GetNameRanges(CommandReturnObject &result) {
347   ConstString name(m_options.func_name.c_str());
348 
349   ModuleFunctionSearchOptions function_options;
350   function_options.include_symbols = true;
351   function_options.include_inlines = true;
352 
353   // Find functions matching the given name.
354   SymbolContextList sc_list;
355   GetSelectedTarget().GetImages().FindFunctions(name, eFunctionNameTypeAuto,
356                                                 function_options, sc_list);
357 
358   std::vector<AddressRange> ranges;
359   llvm::Error range_errs = llvm::Error::success();
360   AddressRange range;
361   const uint32_t scope =
362       eSymbolContextBlock | eSymbolContextFunction | eSymbolContextSymbol;
363   const bool use_inline_block_range = true;
364   for (SymbolContext sc : sc_list.SymbolContexts()) {
365     for (uint32_t range_idx = 0;
366          sc.GetAddressRange(scope, range_idx, use_inline_block_range, range);
367          ++range_idx) {
368       if (llvm::Error err = CheckRangeSize(range, "a range"))
369         range_errs = joinErrors(std::move(range_errs), std::move(err));
370       else
371         ranges.push_back(range);
372     }
373   }
374   if (ranges.empty()) {
375     if (range_errs)
376       return std::move(range_errs);
377     return llvm::createStringError(llvm::inconvertibleErrorCode(),
378                                    "Unable to find symbol with name '%s'.\n",
379                                    name.GetCString());
380   }
381   if (range_errs)
382     result.AppendWarning(toString(std::move(range_errs)));
383   return ranges;
384 }
385 
386 llvm::Expected<std::vector<AddressRange>>
387 CommandObjectDisassemble::GetPCRanges() {
388   Process *process = m_exe_ctx.GetProcessPtr();
389   StackFrame *frame = m_exe_ctx.GetFramePtr();
390   if (!frame) {
391     if (process) {
392       return llvm::createStringError(
393           llvm::inconvertibleErrorCode(),
394           "Cannot disassemble around the current "
395           "function without the process being stopped.\n");
396     } else {
397       return llvm::createStringError(llvm::inconvertibleErrorCode(),
398                                      "Cannot disassemble around the current "
399                                      "PC without a selected frame: "
400                                      "no currently running process.\n");
401     }
402   }
403 
404   if (m_options.num_instructions == 0) {
405     // Disassembling at the PC always disassembles some number of
406     // instructions (not the whole function).
407     m_options.num_instructions = default_disasm_num_ins;
408   }
409   return std::vector<AddressRange>{{frame->GetFrameCodeAddress(), 0}};
410 }
411 
412 llvm::Expected<std::vector<AddressRange>>
413 CommandObjectDisassemble::GetStartEndAddressRanges() {
414   addr_t size = 0;
415   if (m_options.end_addr != LLDB_INVALID_ADDRESS) {
416     if (m_options.end_addr <= m_options.start_addr) {
417       return llvm::createStringError(llvm::inconvertibleErrorCode(),
418                                      "End address before start address.");
419     }
420     size = m_options.end_addr - m_options.start_addr;
421   }
422   return std::vector<AddressRange>{{Address(m_options.start_addr), size}};
423 }
424 
425 llvm::Expected<std::vector<AddressRange>>
426 CommandObjectDisassemble::GetRangesForSelectedMode(
427     CommandReturnObject &result) {
428   if (m_options.symbol_containing_addr != LLDB_INVALID_ADDRESS)
429     return CommandObjectDisassemble::GetContainingAddressRanges();
430   if (m_options.current_function)
431     return CommandObjectDisassemble::GetCurrentFunctionRanges();
432   if (m_options.frame_line)
433     return CommandObjectDisassemble::GetCurrentLineRanges();
434   if (!m_options.func_name.empty())
435     return CommandObjectDisassemble::GetNameRanges(result);
436   if (m_options.start_addr != LLDB_INVALID_ADDRESS)
437     return CommandObjectDisassemble::GetStartEndAddressRanges();
438   return CommandObjectDisassemble::GetPCRanges();
439 }
440 
441 bool CommandObjectDisassemble::DoExecute(Args &command,
442                                          CommandReturnObject &result) {
443   Target *target = &GetSelectedTarget();
444 
445   if (!m_options.arch.IsValid())
446     m_options.arch = target->GetArchitecture();
447 
448   if (!m_options.arch.IsValid()) {
449     result.AppendError(
450         "use the --arch option or set the target architecture to disassemble");
451     return false;
452   }
453 
454   const char *plugin_name = m_options.GetPluginName();
455   const char *flavor_string = m_options.GetFlavorString();
456 
457   DisassemblerSP disassembler =
458       Disassembler::FindPlugin(m_options.arch, flavor_string, plugin_name);
459 
460   if (!disassembler) {
461     if (plugin_name) {
462       result.AppendErrorWithFormat(
463           "Unable to find Disassembler plug-in named '%s' that supports the "
464           "'%s' architecture.\n",
465           plugin_name, m_options.arch.GetArchitectureName());
466     } else
467       result.AppendErrorWithFormat(
468           "Unable to find Disassembler plug-in for the '%s' architecture.\n",
469           m_options.arch.GetArchitectureName());
470     return false;
471   } else if (flavor_string != nullptr && !disassembler->FlavorValidForArchSpec(
472                                              m_options.arch, flavor_string))
473     result.AppendWarningWithFormat(
474         "invalid disassembler flavor \"%s\", using default.\n", flavor_string);
475 
476   result.SetStatus(eReturnStatusSuccessFinishResult);
477 
478   if (!command.empty()) {
479     result.AppendErrorWithFormat(
480         "\"disassemble\" arguments are specified as options.\n");
481     const int terminal_width =
482         GetCommandInterpreter().GetDebugger().GetTerminalWidth();
483     GetOptions()->GenerateOptionUsage(result.GetErrorStream(), *this,
484                                       terminal_width);
485     return false;
486   }
487 
488   if (m_options.show_mixed && m_options.num_lines_context == 0)
489     m_options.num_lines_context = 2;
490 
491   // Always show the PC in the disassembly
492   uint32_t options = Disassembler::eOptionMarkPCAddress;
493 
494   // Mark the source line for the current PC only if we are doing mixed source
495   // and assembly
496   if (m_options.show_mixed)
497     options |= Disassembler::eOptionMarkPCSourceLine;
498 
499   if (m_options.show_bytes)
500     options |= Disassembler::eOptionShowBytes;
501 
502   if (m_options.show_control_flow_kind)
503     options |= Disassembler::eOptionShowControlFlowKind;
504 
505   if (m_options.raw)
506     options |= Disassembler::eOptionRawOuput;
507 
508   llvm::Expected<std::vector<AddressRange>> ranges =
509       GetRangesForSelectedMode(result);
510   if (!ranges) {
511     result.AppendError(toString(ranges.takeError()));
512     return result.Succeeded();
513   }
514 
515   bool print_sc_header = ranges->size() > 1;
516   for (AddressRange cur_range : *ranges) {
517     Disassembler::Limit limit;
518     if (m_options.num_instructions == 0) {
519       limit = {Disassembler::Limit::Bytes, cur_range.GetByteSize()};
520       if (limit.value == 0)
521         limit.value = default_disasm_byte_size;
522     } else {
523       limit = {Disassembler::Limit::Instructions, m_options.num_instructions};
524     }
525     if (Disassembler::Disassemble(
526             GetDebugger(), m_options.arch, plugin_name, flavor_string,
527             m_exe_ctx, cur_range.GetBaseAddress(), limit, m_options.show_mixed,
528             m_options.show_mixed ? m_options.num_lines_context : 0, options,
529             result.GetOutputStream())) {
530       result.SetStatus(eReturnStatusSuccessFinishResult);
531     } else {
532       if (m_options.symbol_containing_addr != LLDB_INVALID_ADDRESS) {
533         result.AppendErrorWithFormat(
534             "Failed to disassemble memory in function at 0x%8.8" PRIx64 ".\n",
535             m_options.symbol_containing_addr);
536       } else {
537         result.AppendErrorWithFormat(
538             "Failed to disassemble memory at 0x%8.8" PRIx64 ".\n",
539             cur_range.GetBaseAddress().GetLoadAddress(target));
540       }
541     }
542     if (print_sc_header)
543       result.GetOutputStream() << "\n";
544   }
545 
546   return result.Succeeded();
547 }
548