1 //===-- CommandObjectRegister.cpp -------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 #include "llvm/ADT/STLExtras.h"
14 
15 // Project includes
16 #include "CommandObjectRegister.h"
17 #include "lldb/Core/DataExtractor.h"
18 #include "lldb/Core/Debugger.h"
19 #include "lldb/Core/RegisterValue.h"
20 #include "lldb/Core/Scalar.h"
21 #include "lldb/Interpreter/Args.h"
22 #include "lldb/Interpreter/CommandInterpreter.h"
23 #include "lldb/Interpreter/CommandReturnObject.h"
24 #include "lldb/Interpreter/OptionGroupFormat.h"
25 #include "lldb/Interpreter/OptionValueArray.h"
26 #include "lldb/Interpreter/OptionValueBoolean.h"
27 #include "lldb/Interpreter/OptionValueUInt64.h"
28 #include "lldb/Interpreter/Options.h"
29 #include "lldb/Target/ExecutionContext.h"
30 #include "lldb/Target/Process.h"
31 #include "lldb/Target/RegisterContext.h"
32 #include "lldb/Target/SectionLoadList.h"
33 #include "lldb/Target/Thread.h"
34 
35 using namespace lldb;
36 using namespace lldb_private;
37 
38 //----------------------------------------------------------------------
39 // "register read"
40 //----------------------------------------------------------------------
41 
42 static OptionDefinition g_register_read_options[] = {
43     // clang-format off
44   { LLDB_OPT_SET_ALL, false, "alternate", 'A', OptionParser::eNoArgument,       nullptr, nullptr, 0, eArgTypeNone,  "Display register names using the alternate register name if there is one." },
45   { LLDB_OPT_SET_1,   false, "set",       's', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeIndex, "Specify which register sets to dump by index." },
46   { LLDB_OPT_SET_2,   false, "all",       'a', OptionParser::eNoArgument,       nullptr, nullptr, 0, eArgTypeNone,  "Show all register sets." },
47     // clang-format on
48 };
49 
50 class CommandObjectRegisterRead : public CommandObjectParsed {
51 public:
52   CommandObjectRegisterRead(CommandInterpreter &interpreter)
53       : CommandObjectParsed(
54             interpreter, "register read",
55             "Dump the contents of one or more register values from the current "
56             "frame.  If no register is specified, dumps them all.",
57             nullptr,
58             eCommandRequiresFrame | eCommandRequiresRegContext |
59                 eCommandProcessMustBeLaunched | eCommandProcessMustBePaused),
60         m_option_group(), m_format_options(eFormatDefault),
61         m_command_options() {
62     CommandArgumentEntry arg;
63     CommandArgumentData register_arg;
64 
65     // Define the first (and only) variant of this arg.
66     register_arg.arg_type = eArgTypeRegisterName;
67     register_arg.arg_repetition = eArgRepeatStar;
68 
69     // There is only one variant this argument could be; put it into the
70     // argument entry.
71     arg.push_back(register_arg);
72 
73     // Push the data for the first argument into the m_arguments vector.
74     m_arguments.push_back(arg);
75 
76     // Add the "--format"
77     m_option_group.Append(&m_format_options,
78                           OptionGroupFormat::OPTION_GROUP_FORMAT |
79                               OptionGroupFormat::OPTION_GROUP_GDB_FMT,
80                           LLDB_OPT_SET_ALL);
81     m_option_group.Append(&m_command_options);
82     m_option_group.Finalize();
83   }
84 
85   ~CommandObjectRegisterRead() override = default;
86 
87   Options *GetOptions() override { return &m_option_group; }
88 
89   bool DumpRegister(const ExecutionContext &exe_ctx, Stream &strm,
90                     RegisterContext *reg_ctx, const RegisterInfo *reg_info) {
91     if (reg_info) {
92       RegisterValue reg_value;
93 
94       if (reg_ctx->ReadRegister(reg_info, reg_value)) {
95         strm.Indent();
96 
97         bool prefix_with_altname = (bool)m_command_options.alternate_name;
98         bool prefix_with_name = !prefix_with_altname;
99         reg_value.Dump(&strm, reg_info, prefix_with_name, prefix_with_altname,
100                        m_format_options.GetFormat(), 8);
101         if ((reg_info->encoding == eEncodingUint) ||
102             (reg_info->encoding == eEncodingSint)) {
103           Process *process = exe_ctx.GetProcessPtr();
104           if (process && reg_info->byte_size == process->GetAddressByteSize()) {
105             addr_t reg_addr = reg_value.GetAsUInt64(LLDB_INVALID_ADDRESS);
106             if (reg_addr != LLDB_INVALID_ADDRESS) {
107               Address so_reg_addr;
108               if (exe_ctx.GetTargetRef()
109                       .GetSectionLoadList()
110                       .ResolveLoadAddress(reg_addr, so_reg_addr)) {
111                 strm.PutCString("  ");
112                 so_reg_addr.Dump(&strm, exe_ctx.GetBestExecutionContextScope(),
113                                  Address::DumpStyleResolvedDescription);
114               }
115             }
116           }
117         }
118         strm.EOL();
119         return true;
120       }
121     }
122     return false;
123   }
124 
125   bool DumpRegisterSet(const ExecutionContext &exe_ctx, Stream &strm,
126                        RegisterContext *reg_ctx, size_t set_idx,
127                        bool primitive_only = false) {
128     uint32_t unavailable_count = 0;
129     uint32_t available_count = 0;
130 
131     if (!reg_ctx)
132       return false; // thread has no registers (i.e. core files are corrupt,
133                     // incomplete crash logs...)
134 
135     const RegisterSet *const reg_set = reg_ctx->GetRegisterSet(set_idx);
136     if (reg_set) {
137       strm.Printf("%s:\n", (reg_set->name ? reg_set->name : "unknown"));
138       strm.IndentMore();
139       const size_t num_registers = reg_set->num_registers;
140       for (size_t reg_idx = 0; reg_idx < num_registers; ++reg_idx) {
141         const uint32_t reg = reg_set->registers[reg_idx];
142         const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(reg);
143         // Skip the dumping of derived register if primitive_only is true.
144         if (primitive_only && reg_info && reg_info->value_regs)
145           continue;
146 
147         if (DumpRegister(exe_ctx, strm, reg_ctx, reg_info))
148           ++available_count;
149         else
150           ++unavailable_count;
151       }
152       strm.IndentLess();
153       if (unavailable_count) {
154         strm.Indent();
155         strm.Printf("%u registers were unavailable.\n", unavailable_count);
156       }
157       strm.EOL();
158     }
159     return available_count > 0;
160   }
161 
162 protected:
163   bool DoExecute(Args &command, CommandReturnObject &result) override {
164     Stream &strm = result.GetOutputStream();
165     RegisterContext *reg_ctx = m_exe_ctx.GetRegisterContext();
166 
167     const RegisterInfo *reg_info = nullptr;
168     if (command.GetArgumentCount() == 0) {
169       size_t set_idx;
170 
171       size_t num_register_sets = 1;
172       const size_t set_array_size = m_command_options.set_indexes.GetSize();
173       if (set_array_size > 0) {
174         for (size_t i = 0; i < set_array_size; ++i) {
175           set_idx = m_command_options.set_indexes[i]->GetUInt64Value(UINT32_MAX,
176                                                                      nullptr);
177           if (set_idx < reg_ctx->GetRegisterSetCount()) {
178             if (!DumpRegisterSet(m_exe_ctx, strm, reg_ctx, set_idx)) {
179               if (errno)
180                 result.AppendErrorWithFormat("register read failed: %s\n",
181                                              strerror(errno));
182               else
183                 result.AppendError("unknown error while reading registers.\n");
184               result.SetStatus(eReturnStatusFailed);
185               break;
186             }
187           } else {
188             result.AppendErrorWithFormat(
189                 "invalid register set index: %" PRIu64 "\n", (uint64_t)set_idx);
190             result.SetStatus(eReturnStatusFailed);
191             break;
192           }
193         }
194       } else {
195         if (m_command_options.dump_all_sets)
196           num_register_sets = reg_ctx->GetRegisterSetCount();
197 
198         for (set_idx = 0; set_idx < num_register_sets; ++set_idx) {
199           // When dump_all_sets option is set, dump primitive as well as derived
200           // registers.
201           DumpRegisterSet(m_exe_ctx, strm, reg_ctx, set_idx,
202                           !m_command_options.dump_all_sets.GetCurrentValue());
203         }
204       }
205     } else {
206       if (m_command_options.dump_all_sets) {
207         result.AppendError("the --all option can't be used when registers "
208                            "names are supplied as arguments\n");
209         result.SetStatus(eReturnStatusFailed);
210       } else if (m_command_options.set_indexes.GetSize() > 0) {
211         result.AppendError("the --set <set> option can't be used when "
212                            "registers names are supplied as arguments\n");
213         result.SetStatus(eReturnStatusFailed);
214       } else {
215         const char *arg_cstr;
216         for (int arg_idx = 0;
217              (arg_cstr = command.GetArgumentAtIndex(arg_idx)) != nullptr;
218              ++arg_idx) {
219           // in most LLDB commands we accept $rbx as the name for register RBX -
220           // and here we would
221           // reject it and non-existant. we should be more consistent towards
222           // the user and allow them
223           // to say reg read $rbx - internally, however, we should be strict and
224           // not allow ourselves
225           // to call our registers $rbx in our own API
226           if (*arg_cstr == '$')
227             arg_cstr = arg_cstr + 1;
228           reg_info = reg_ctx->GetRegisterInfoByName(arg_cstr);
229 
230           if (reg_info) {
231             if (!DumpRegister(m_exe_ctx, strm, reg_ctx, reg_info))
232               strm.Printf("%-12s = error: unavailable\n", reg_info->name);
233           } else {
234             result.AppendErrorWithFormat("Invalid register name '%s'.\n",
235                                          arg_cstr);
236           }
237         }
238       }
239     }
240     return result.Succeeded();
241   }
242 
243   class CommandOptions : public OptionGroup {
244   public:
245     CommandOptions()
246         : OptionGroup(),
247           set_indexes(OptionValue::ConvertTypeToMask(OptionValue::eTypeUInt64)),
248           dump_all_sets(false, false), // Initial and default values are false
249           alternate_name(false, false) {}
250 
251     ~CommandOptions() override = default;
252 
253     llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
254       return llvm::makeArrayRef(g_register_read_options);
255     }
256 
257     void OptionParsingStarting(ExecutionContext *execution_context) override {
258       set_indexes.Clear();
259       dump_all_sets.Clear();
260       alternate_name.Clear();
261     }
262 
263     Error SetOptionValue(uint32_t option_idx, llvm::StringRef option_value,
264                          ExecutionContext *execution_context) override {
265       Error error;
266       const int short_option = GetDefinitions()[option_idx].short_option;
267       switch (short_option) {
268       case 's': {
269         OptionValueSP value_sp(OptionValueUInt64::Create(option_value, error));
270         if (value_sp)
271           set_indexes.AppendValue(value_sp);
272       } break;
273 
274       case 'a':
275         // When we don't use OptionValue::SetValueFromCString(const char *) to
276         // set an option value, it won't be marked as being set in the options
277         // so we make a call to let users know the value was set via option
278         dump_all_sets.SetCurrentValue(true);
279         dump_all_sets.SetOptionWasSet();
280         break;
281 
282       case 'A':
283         // When we don't use OptionValue::SetValueFromCString(const char *) to
284         // set an option value, it won't be marked as being set in the options
285         // so we make a call to let users know the value was set via option
286         alternate_name.SetCurrentValue(true);
287         dump_all_sets.SetOptionWasSet();
288         break;
289 
290       default:
291         error.SetErrorStringWithFormat("unrecognized short option '%c'",
292                                        short_option);
293         break;
294       }
295       return error;
296     }
297 
298     // Instance variables to hold the values for command options.
299     OptionValueArray set_indexes;
300     OptionValueBoolean dump_all_sets;
301     OptionValueBoolean alternate_name;
302   };
303 
304   OptionGroupOptions m_option_group;
305   OptionGroupFormat m_format_options;
306   CommandOptions m_command_options;
307 };
308 
309 //----------------------------------------------------------------------
310 // "register write"
311 //----------------------------------------------------------------------
312 class CommandObjectRegisterWrite : public CommandObjectParsed {
313 public:
314   CommandObjectRegisterWrite(CommandInterpreter &interpreter)
315       : CommandObjectParsed(interpreter, "register write",
316                             "Modify a single register value.", nullptr,
317                             eCommandRequiresFrame | eCommandRequiresRegContext |
318                                 eCommandProcessMustBeLaunched |
319                                 eCommandProcessMustBePaused) {
320     CommandArgumentEntry arg1;
321     CommandArgumentEntry arg2;
322     CommandArgumentData register_arg;
323     CommandArgumentData value_arg;
324 
325     // Define the first (and only) variant of this arg.
326     register_arg.arg_type = eArgTypeRegisterName;
327     register_arg.arg_repetition = eArgRepeatPlain;
328 
329     // There is only one variant this argument could be; put it into the
330     // argument entry.
331     arg1.push_back(register_arg);
332 
333     // Define the first (and only) variant of this arg.
334     value_arg.arg_type = eArgTypeValue;
335     value_arg.arg_repetition = eArgRepeatPlain;
336 
337     // There is only one variant this argument could be; put it into the
338     // argument entry.
339     arg2.push_back(value_arg);
340 
341     // Push the data for the first argument into the m_arguments vector.
342     m_arguments.push_back(arg1);
343     m_arguments.push_back(arg2);
344   }
345 
346   ~CommandObjectRegisterWrite() override = default;
347 
348 protected:
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       const char *reg_name = command.GetArgumentAtIndex(0);
359       const char *value_str = command.GetArgumentAtIndex(1);
360 
361       // in most LLDB commands we accept $rbx as the name for register RBX - and
362       // here we would
363       // reject it and non-existant. we should be more consistent towards the
364       // user and allow them
365       // to say reg write $rbx - internally, however, we should be strict and
366       // not allow ourselves
367       // to call our registers $rbx in our own API
368       if (reg_name && *reg_name == '$')
369         reg_name = reg_name + 1;
370 
371       const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName(reg_name);
372 
373       if (reg_info) {
374         RegisterValue reg_value;
375 
376         Error error(reg_value.SetValueFromCString(reg_info, value_str));
377         if (error.Success()) {
378           if (reg_ctx->WriteRegister(reg_info, reg_value)) {
379             // Toss all frames and anything else in the thread
380             // after a register has been written.
381             m_exe_ctx.GetThreadRef().Flush();
382             result.SetStatus(eReturnStatusSuccessFinishNoResult);
383             return true;
384           }
385         }
386         if (error.AsCString()) {
387           result.AppendErrorWithFormat(
388               "Failed to write register '%s' with value '%s': %s\n", reg_name,
389               value_str, error.AsCString());
390         } else {
391           result.AppendErrorWithFormat(
392               "Failed to write register '%s' with value '%s'", reg_name,
393               value_str);
394         }
395         result.SetStatus(eReturnStatusFailed);
396       } else {
397         result.AppendErrorWithFormat("Register not found for '%s'.\n",
398                                      reg_name);
399         result.SetStatus(eReturnStatusFailed);
400       }
401     }
402     return result.Succeeded();
403   }
404 };
405 
406 //----------------------------------------------------------------------
407 // CommandObjectRegister constructor
408 //----------------------------------------------------------------------
409 CommandObjectRegister::CommandObjectRegister(CommandInterpreter &interpreter)
410     : CommandObjectMultiword(interpreter, "register",
411                              "Commands to access registers for the current "
412                              "thread and stack frame.",
413                              "register [read|write] ...") {
414   LoadSubCommand("read",
415                  CommandObjectSP(new CommandObjectRegisterRead(interpreter)));
416   LoadSubCommand("write",
417                  CommandObjectSP(new CommandObjectRegisterWrite(interpreter)));
418 }
419 
420 CommandObjectRegister::~CommandObjectRegister() = default;
421