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