1 //===-- CommandObjectRegister.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 "CommandObjectRegister.h"
10 #include "lldb/Core/Debugger.h"
11 #include "lldb/Core/DumpRegisterValue.h"
12 #include "lldb/Host/OptionParser.h"
13 #include "lldb/Interpreter/CommandReturnObject.h"
14 #include "lldb/Interpreter/OptionGroupFormat.h"
15 #include "lldb/Interpreter/OptionValueArray.h"
16 #include "lldb/Interpreter/OptionValueBoolean.h"
17 #include "lldb/Interpreter/OptionValueUInt64.h"
18 #include "lldb/Interpreter/Options.h"
19 #include "lldb/Target/ExecutionContext.h"
20 #include "lldb/Target/Process.h"
21 #include "lldb/Target/RegisterContext.h"
22 #include "lldb/Target/SectionLoadList.h"
23 #include "lldb/Target/Thread.h"
24 #include "lldb/Utility/Args.h"
25 #include "lldb/Utility/DataExtractor.h"
26 #include "lldb/Utility/RegisterValue.h"
27 #include "llvm/Support/Errno.h"
28
29 using namespace lldb;
30 using namespace lldb_private;
31
32 // "register read"
33 #define LLDB_OPTIONS_register_read
34 #include "CommandOptions.inc"
35
36 class CommandObjectRegisterRead : public CommandObjectParsed {
37 public:
CommandObjectRegisterRead(CommandInterpreter & interpreter)38 CommandObjectRegisterRead(CommandInterpreter &interpreter)
39 : CommandObjectParsed(
40 interpreter, "register read",
41 "Dump the contents of one or more register values from the current "
42 "frame. If no register is specified, dumps them all.",
43 nullptr,
44 eCommandRequiresFrame | eCommandRequiresRegContext |
45 eCommandProcessMustBeLaunched | eCommandProcessMustBePaused),
46 m_option_group(), m_format_options(eFormatDefault),
47 m_command_options() {
48 CommandArgumentEntry arg;
49 CommandArgumentData register_arg;
50
51 // Define the first (and only) variant of this arg.
52 register_arg.arg_type = eArgTypeRegisterName;
53 register_arg.arg_repetition = eArgRepeatStar;
54
55 // There is only one variant this argument could be; put it into the
56 // argument entry.
57 arg.push_back(register_arg);
58
59 // Push the data for the first argument into the m_arguments vector.
60 m_arguments.push_back(arg);
61
62 // Add the "--format"
63 m_option_group.Append(&m_format_options,
64 OptionGroupFormat::OPTION_GROUP_FORMAT |
65 OptionGroupFormat::OPTION_GROUP_GDB_FMT,
66 LLDB_OPT_SET_ALL);
67 m_option_group.Append(&m_command_options);
68 m_option_group.Finalize();
69 }
70
71 ~CommandObjectRegisterRead() override = default;
72
73 void
HandleArgumentCompletion(CompletionRequest & request,OptionElementVector & opt_element_vector)74 HandleArgumentCompletion(CompletionRequest &request,
75 OptionElementVector &opt_element_vector) override {
76 if (!m_exe_ctx.HasProcessScope())
77 return;
78
79 CommandCompletions::InvokeCommonCompletionCallbacks(
80 GetCommandInterpreter(), CommandCompletions::eRegisterCompletion,
81 request, nullptr);
82 }
83
GetOptions()84 Options *GetOptions() override { return &m_option_group; }
85
DumpRegister(const ExecutionContext & exe_ctx,Stream & strm,RegisterContext * reg_ctx,const RegisterInfo * reg_info)86 bool DumpRegister(const ExecutionContext &exe_ctx, Stream &strm,
87 RegisterContext *reg_ctx, const RegisterInfo *reg_info) {
88 if (reg_info) {
89 RegisterValue reg_value;
90
91 if (reg_ctx->ReadRegister(reg_info, reg_value)) {
92 strm.Indent();
93
94 bool prefix_with_altname = (bool)m_command_options.alternate_name;
95 bool prefix_with_name = !prefix_with_altname;
96 DumpRegisterValue(reg_value, &strm, reg_info, prefix_with_name,
97 prefix_with_altname, m_format_options.GetFormat(), 8);
98 if ((reg_info->encoding == eEncodingUint) ||
99 (reg_info->encoding == eEncodingSint)) {
100 Process *process = exe_ctx.GetProcessPtr();
101 if (process && reg_info->byte_size == process->GetAddressByteSize()) {
102 addr_t reg_addr = reg_value.GetAsUInt64(LLDB_INVALID_ADDRESS);
103 if (reg_addr != LLDB_INVALID_ADDRESS) {
104 Address so_reg_addr;
105 if (exe_ctx.GetTargetRef()
106 .GetSectionLoadList()
107 .ResolveLoadAddress(reg_addr, so_reg_addr)) {
108 strm.PutCString(" ");
109 so_reg_addr.Dump(&strm, exe_ctx.GetBestExecutionContextScope(),
110 Address::DumpStyleResolvedDescription);
111 }
112 }
113 }
114 }
115 strm.EOL();
116 return true;
117 }
118 }
119 return false;
120 }
121
DumpRegisterSet(const ExecutionContext & exe_ctx,Stream & strm,RegisterContext * reg_ctx,size_t set_idx,bool primitive_only=false)122 bool DumpRegisterSet(const ExecutionContext &exe_ctx, Stream &strm,
123 RegisterContext *reg_ctx, size_t set_idx,
124 bool primitive_only = false) {
125 uint32_t unavailable_count = 0;
126 uint32_t available_count = 0;
127
128 if (!reg_ctx)
129 return false; // thread has no registers (i.e. core files are corrupt,
130 // incomplete crash logs...)
131
132 const RegisterSet *const reg_set = reg_ctx->GetRegisterSet(set_idx);
133 if (reg_set) {
134 strm.Printf("%s:\n", (reg_set->name ? reg_set->name : "unknown"));
135 strm.IndentMore();
136 const size_t num_registers = reg_set->num_registers;
137 for (size_t reg_idx = 0; reg_idx < num_registers; ++reg_idx) {
138 const uint32_t reg = reg_set->registers[reg_idx];
139 const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(reg);
140 // Skip the dumping of derived register if primitive_only is true.
141 if (primitive_only && reg_info && reg_info->value_regs)
142 continue;
143
144 if (DumpRegister(exe_ctx, strm, reg_ctx, reg_info))
145 ++available_count;
146 else
147 ++unavailable_count;
148 }
149 strm.IndentLess();
150 if (unavailable_count) {
151 strm.Indent();
152 strm.Printf("%u registers were unavailable.\n", unavailable_count);
153 }
154 strm.EOL();
155 }
156 return available_count > 0;
157 }
158
159 protected:
DoExecute(Args & command,CommandReturnObject & result)160 bool DoExecute(Args &command, CommandReturnObject &result) override {
161 Stream &strm = result.GetOutputStream();
162 RegisterContext *reg_ctx = m_exe_ctx.GetRegisterContext();
163
164 const RegisterInfo *reg_info = nullptr;
165 if (command.GetArgumentCount() == 0) {
166 size_t set_idx;
167
168 size_t num_register_sets = 1;
169 const size_t set_array_size = m_command_options.set_indexes.GetSize();
170 if (set_array_size > 0) {
171 for (size_t i = 0; i < set_array_size; ++i) {
172 set_idx = m_command_options.set_indexes[i]->GetUInt64Value(UINT32_MAX,
173 nullptr);
174 if (set_idx < reg_ctx->GetRegisterSetCount()) {
175 if (!DumpRegisterSet(m_exe_ctx, strm, reg_ctx, set_idx)) {
176 if (errno)
177 result.AppendErrorWithFormatv("register read failed: {0}\n",
178 llvm::sys::StrError());
179 else
180 result.AppendError("unknown error while reading registers.\n");
181 result.SetStatus(eReturnStatusFailed);
182 break;
183 }
184 } else {
185 result.AppendErrorWithFormat(
186 "invalid register set index: %" PRIu64 "\n", (uint64_t)set_idx);
187 result.SetStatus(eReturnStatusFailed);
188 break;
189 }
190 }
191 } else {
192 if (m_command_options.dump_all_sets)
193 num_register_sets = reg_ctx->GetRegisterSetCount();
194
195 for (set_idx = 0; set_idx < num_register_sets; ++set_idx) {
196 // When dump_all_sets option is set, dump primitive as well as
197 // derived registers.
198 DumpRegisterSet(m_exe_ctx, strm, reg_ctx, set_idx,
199 !m_command_options.dump_all_sets.GetCurrentValue());
200 }
201 }
202 } else {
203 if (m_command_options.dump_all_sets) {
204 result.AppendError("the --all option can't be used when registers "
205 "names are supplied as arguments\n");
206 result.SetStatus(eReturnStatusFailed);
207 } else if (m_command_options.set_indexes.GetSize() > 0) {
208 result.AppendError("the --set <set> option can't be used when "
209 "registers names are supplied as arguments\n");
210 result.SetStatus(eReturnStatusFailed);
211 } else {
212 for (auto &entry : command) {
213 // in most LLDB commands we accept $rbx as the name for register RBX
214 // - and here we would reject it and non-existant. we should be more
215 // consistent towards the user and allow them to say reg read $rbx -
216 // internally, however, we should be strict and not allow ourselves
217 // to call our registers $rbx in our own API
218 auto arg_str = entry.ref();
219 arg_str.consume_front("$");
220
221 reg_info = reg_ctx->GetRegisterInfoByName(arg_str);
222
223 if (reg_info) {
224 if (!DumpRegister(m_exe_ctx, strm, reg_ctx, reg_info))
225 strm.Printf("%-12s = error: unavailable\n", reg_info->name);
226 } else {
227 result.AppendErrorWithFormat("Invalid register name '%s'.\n",
228 arg_str.str().c_str());
229 }
230 }
231 }
232 }
233 return result.Succeeded();
234 }
235
236 class CommandOptions : public OptionGroup {
237 public:
CommandOptions()238 CommandOptions()
239 : OptionGroup(),
240 set_indexes(OptionValue::ConvertTypeToMask(OptionValue::eTypeUInt64)),
241 dump_all_sets(false, false), // Initial and default values are false
242 alternate_name(false, false) {}
243
244 ~CommandOptions() override = default;
245
GetDefinitions()246 llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
247 return llvm::makeArrayRef(g_register_read_options);
248 }
249
OptionParsingStarting(ExecutionContext * execution_context)250 void OptionParsingStarting(ExecutionContext *execution_context) override {
251 set_indexes.Clear();
252 dump_all_sets.Clear();
253 alternate_name.Clear();
254 }
255
SetOptionValue(uint32_t option_idx,llvm::StringRef option_value,ExecutionContext * execution_context)256 Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_value,
257 ExecutionContext *execution_context) override {
258 Status error;
259 const int short_option = GetDefinitions()[option_idx].short_option;
260 switch (short_option) {
261 case 's': {
262 OptionValueSP value_sp(OptionValueUInt64::Create(option_value, error));
263 if (value_sp)
264 set_indexes.AppendValue(value_sp);
265 } break;
266
267 case 'a':
268 // When we don't use OptionValue::SetValueFromCString(const char *) to
269 // set an option value, it won't be marked as being set in the options
270 // so we make a call to let users know the value was set via option
271 dump_all_sets.SetCurrentValue(true);
272 dump_all_sets.SetOptionWasSet();
273 break;
274
275 case 'A':
276 // When we don't use OptionValue::SetValueFromCString(const char *) to
277 // set an option value, it won't be marked as being set in the options
278 // so we make a call to let users know the value was set via option
279 alternate_name.SetCurrentValue(true);
280 dump_all_sets.SetOptionWasSet();
281 break;
282
283 default:
284 llvm_unreachable("Unimplemented option");
285 }
286 return error;
287 }
288
289 // Instance variables to hold the values for command options.
290 OptionValueArray set_indexes;
291 OptionValueBoolean dump_all_sets;
292 OptionValueBoolean alternate_name;
293 };
294
295 OptionGroupOptions m_option_group;
296 OptionGroupFormat m_format_options;
297 CommandOptions m_command_options;
298 };
299
300 // "register write"
301 class CommandObjectRegisterWrite : public CommandObjectParsed {
302 public:
CommandObjectRegisterWrite(CommandInterpreter & interpreter)303 CommandObjectRegisterWrite(CommandInterpreter &interpreter)
304 : CommandObjectParsed(interpreter, "register write",
305 "Modify a single register value.", nullptr,
306 eCommandRequiresFrame | eCommandRequiresRegContext |
307 eCommandProcessMustBeLaunched |
308 eCommandProcessMustBePaused) {
309 CommandArgumentEntry arg1;
310 CommandArgumentEntry arg2;
311 CommandArgumentData register_arg;
312 CommandArgumentData value_arg;
313
314 // Define the first (and only) variant of this arg.
315 register_arg.arg_type = eArgTypeRegisterName;
316 register_arg.arg_repetition = eArgRepeatPlain;
317
318 // There is only one variant this argument could be; put it into the
319 // argument entry.
320 arg1.push_back(register_arg);
321
322 // Define the first (and only) variant of this arg.
323 value_arg.arg_type = eArgTypeValue;
324 value_arg.arg_repetition = eArgRepeatPlain;
325
326 // There is only one variant this argument could be; put it into the
327 // argument entry.
328 arg2.push_back(value_arg);
329
330 // Push the data for the first argument into the m_arguments vector.
331 m_arguments.push_back(arg1);
332 m_arguments.push_back(arg2);
333 }
334
335 ~CommandObjectRegisterWrite() override = default;
336
337 void
HandleArgumentCompletion(CompletionRequest & request,OptionElementVector & opt_element_vector)338 HandleArgumentCompletion(CompletionRequest &request,
339 OptionElementVector &opt_element_vector) override {
340 if (!m_exe_ctx.HasProcessScope() || request.GetCursorIndex() != 0)
341 return;
342
343 CommandCompletions::InvokeCommonCompletionCallbacks(
344 GetCommandInterpreter(), CommandCompletions::eRegisterCompletion,
345 request, nullptr);
346 }
347
348 protected:
DoExecute(Args & command,CommandReturnObject & result)349 bool DoExecute(Args &command, CommandReturnObject &result) override {
350 DataExtractor reg_data;
351 RegisterContext *reg_ctx = m_exe_ctx.GetRegisterContext();
352
353 if (command.GetArgumentCount() != 2) {
354 result.AppendError(
355 "register write takes exactly 2 arguments: <reg-name> <value>");
356 result.SetStatus(eReturnStatusFailed);
357 } else {
358 auto reg_name = command[0].ref();
359 auto value_str = command[1].ref();
360
361 // in most LLDB commands we accept $rbx as the name for register RBX -
362 // and here we would reject it and non-existant. we should be more
363 // consistent towards the user and allow them to say reg write $rbx -
364 // internally, however, we should be strict and not allow ourselves to
365 // call our registers $rbx in our own API
366 reg_name.consume_front("$");
367
368 const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName(reg_name);
369
370 if (reg_info) {
371 RegisterValue reg_value;
372
373 Status error(reg_value.SetValueFromString(reg_info, value_str));
374 if (error.Success()) {
375 if (reg_ctx->WriteRegister(reg_info, reg_value)) {
376 // Toss all frames and anything else in the thread after a register
377 // has been written.
378 m_exe_ctx.GetThreadRef().Flush();
379 result.SetStatus(eReturnStatusSuccessFinishNoResult);
380 return true;
381 }
382 }
383 if (error.AsCString()) {
384 result.AppendErrorWithFormat(
385 "Failed to write register '%s' with value '%s': %s\n",
386 reg_name.str().c_str(), value_str.str().c_str(),
387 error.AsCString());
388 } else {
389 result.AppendErrorWithFormat(
390 "Failed to write register '%s' with value '%s'",
391 reg_name.str().c_str(), value_str.str().c_str());
392 }
393 result.SetStatus(eReturnStatusFailed);
394 } else {
395 result.AppendErrorWithFormat("Register not found for '%s'.\n",
396 reg_name.str().c_str());
397 result.SetStatus(eReturnStatusFailed);
398 }
399 }
400 return result.Succeeded();
401 }
402 };
403
404 // CommandObjectRegister constructor
CommandObjectRegister(CommandInterpreter & interpreter)405 CommandObjectRegister::CommandObjectRegister(CommandInterpreter &interpreter)
406 : CommandObjectMultiword(interpreter, "register",
407 "Commands to access registers for the current "
408 "thread and stack frame.",
409 "register [read|write] ...") {
410 LoadSubCommand("read",
411 CommandObjectSP(new CommandObjectRegisterRead(interpreter)));
412 LoadSubCommand("write",
413 CommandObjectSP(new CommandObjectRegisterWrite(interpreter)));
414 }
415
416 CommandObjectRegister::~CommandObjectRegister() = default;
417