xref: /llvm-project/lldb/source/Commands/CommandObjectExpression.cpp (revision c2a58d73ce3aa7a678b9a00b086944c111aea02a)
1 //===-- CommandObjectExpression.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 #include "lldb/lldb-python.h"
11 
12 #include "CommandObjectExpression.h"
13 
14 // C Includes
15 // C++ Includes
16 // Other libraries and framework includes
17 // Project includes
18 #include "lldb/Interpreter/Args.h"
19 #include "lldb/Core/Value.h"
20 #include "lldb/Core/InputReader.h"
21 #include "lldb/Core/ValueObjectVariable.h"
22 #include "lldb/Expression/ClangExpressionVariable.h"
23 #include "lldb/Expression/ClangUserExpression.h"
24 #include "lldb/Expression/ClangFunction.h"
25 #include "lldb/Expression/DWARFExpression.h"
26 #include "lldb/Host/Host.h"
27 #include "lldb/Core/Debugger.h"
28 #include "lldb/Interpreter/CommandInterpreter.h"
29 #include "lldb/Interpreter/CommandReturnObject.h"
30 #include "lldb/Target/ObjCLanguageRuntime.h"
31 #include "lldb/Symbol/ObjectFile.h"
32 #include "lldb/Symbol/Variable.h"
33 #include "lldb/Target/Process.h"
34 #include "lldb/Target/StackFrame.h"
35 #include "lldb/Target/Target.h"
36 #include "lldb/Target/Thread.h"
37 #include "llvm/ADT/StringRef.h"
38 
39 using namespace lldb;
40 using namespace lldb_private;
41 
42 CommandObjectExpression::CommandOptions::CommandOptions () :
43     OptionGroup()
44 {
45 }
46 
47 
48 CommandObjectExpression::CommandOptions::~CommandOptions ()
49 {
50 }
51 
52 OptionDefinition
53 CommandObjectExpression::CommandOptions::g_option_table[] =
54 {
55     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "all-threads",        'a', required_argument, NULL, 0, eArgTypeBoolean,    "Should we run all threads if the execution doesn't complete on one thread."},
56     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "ignore-breakpoints", 'i', required_argument, NULL, 0, eArgTypeBoolean,    "Ignore breakpoint hits while running expressions"},
57     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "timeout",            't', required_argument, NULL, 0, eArgTypeUnsignedInteger,  "Timeout value for running the expression."},
58     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "unwind-on-error",    'u', required_argument, NULL, 0, eArgTypeBoolean,    "Clean up program state if the expression causes a crash, breakpoint hit or signal."},
59 };
60 
61 
62 uint32_t
63 CommandObjectExpression::CommandOptions::GetNumDefinitions ()
64 {
65     return sizeof(g_option_table)/sizeof(OptionDefinition);
66 }
67 
68 Error
69 CommandObjectExpression::CommandOptions::SetOptionValue (CommandInterpreter &interpreter,
70                                                          uint32_t option_idx,
71                                                          const char *option_arg)
72 {
73     Error error;
74 
75     const int short_option = g_option_table[option_idx].short_option;
76 
77     switch (short_option)
78     {
79       //case 'l':
80       //if (language.SetLanguageFromCString (option_arg) == false)
81       //{
82       //    error.SetErrorStringWithFormat("invalid language option argument '%s'", option_arg);
83       //}
84       //break;
85 
86     case 'a':
87         {
88             bool success;
89             bool result;
90             result = Args::StringToBoolean(option_arg, true, &success);
91             if (!success)
92                 error.SetErrorStringWithFormat("invalid all-threads value setting: \"%s\"", option_arg);
93             else
94                 try_all_threads = result;
95         }
96         break;
97 
98     case 'i':
99         {
100             bool success;
101             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
102             if (success)
103                 ignore_breakpoints = tmp_value;
104             else
105                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
106             break;
107         }
108     case 't':
109         {
110             bool success;
111             uint32_t result;
112             result = Args::StringToUInt32(option_arg, 0, 0, &success);
113             if (success)
114                 timeout = result;
115             else
116                 error.SetErrorStringWithFormat ("invalid timeout setting \"%s\"", option_arg);
117         }
118         break;
119 
120     case 'u':
121         {
122             bool success;
123             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
124             if (success)
125                 unwind_on_error = tmp_value;
126             else
127                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
128             break;
129         }
130     default:
131         error.SetErrorStringWithFormat("invalid short option character '%c'", short_option);
132         break;
133     }
134 
135     return error;
136 }
137 
138 void
139 CommandObjectExpression::CommandOptions::OptionParsingStarting (CommandInterpreter &interpreter)
140 {
141     Process *process = interpreter.GetExecutionContext().GetProcessPtr();
142     if (process != NULL)
143     {
144         ignore_breakpoints = process->GetIgnoreBreakpointsInExpressions();
145         unwind_on_error    = process->GetUnwindOnErrorInExpressions();
146     }
147     else
148     {
149         ignore_breakpoints = false;
150         unwind_on_error = true;
151     }
152 
153     show_summary = true;
154     try_all_threads = true;
155     timeout = 0;
156 }
157 
158 const OptionDefinition*
159 CommandObjectExpression::CommandOptions::GetDefinitions ()
160 {
161     return g_option_table;
162 }
163 
164 CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) :
165     CommandObjectRaw (interpreter,
166                       "expression",
167                       "Evaluate a C/ObjC/C++ expression in the current program context, using user defined variables and variables currently in scope.",
168                       NULL,
169                       eFlagProcessMustBePaused | eFlagTryTargetAPILock),
170     m_option_group (interpreter),
171     m_format_options (eFormatDefault),
172     m_command_options (),
173     m_expr_line_count (0),
174     m_expr_lines ()
175 {
176   SetHelpLong(
177 "Timeouts:\n\
178     If the expression can be evaluated statically (without runnning code) then it will be.\n\
179     Otherwise, by default the expression will run on the current thread with a short timeout:\n\
180     currently .25 seconds.  If it doesn't return in that time, the evaluation will be interrupted\n\
181     and resumed with all threads running.  You can use the -a option to disable retrying on all\n\
182     threads.  You can use the -t option to set a shorter timeout.\n\
183 \n\
184 User defined variables:\n\
185     You can define your own variables for convenience or to be used in subsequent expressions.\n\
186     You define them the same way you would define variables in C.  If the first character of \n\
187     your user defined variable is a $, then the variable's value will be available in future\n\
188     expressions, otherwise it will just be available in the current expression.\n\
189 \n\
190 Examples: \n\
191 \n\
192    expr my_struct->a = my_array[3] \n\
193    expr -f bin -- (index * 8) + 5 \n\
194    expr unsigned int $foo = 5\n\
195    expr char c[] = \"foo\"; c[0]\n");
196 
197     CommandArgumentEntry arg;
198     CommandArgumentData expression_arg;
199 
200     // Define the first (and only) variant of this arg.
201     expression_arg.arg_type = eArgTypeExpression;
202     expression_arg.arg_repetition = eArgRepeatPlain;
203 
204     // There is only one variant this argument could be; put it into the argument entry.
205     arg.push_back (expression_arg);
206 
207     // Push the data for the first argument into the m_arguments vector.
208     m_arguments.push_back (arg);
209 
210     // Add the "--format" and "--gdb-format"
211     m_option_group.Append (&m_format_options, OptionGroupFormat::OPTION_GROUP_FORMAT | OptionGroupFormat::OPTION_GROUP_GDB_FMT, LLDB_OPT_SET_1);
212     m_option_group.Append (&m_command_options);
213     m_option_group.Append (&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
214     m_option_group.Finalize();
215 }
216 
217 CommandObjectExpression::~CommandObjectExpression ()
218 {
219 }
220 
221 Options *
222 CommandObjectExpression::GetOptions ()
223 {
224     return &m_option_group;
225 }
226 
227 size_t
228 CommandObjectExpression::MultiLineExpressionCallback
229 (
230     void *baton,
231     InputReader &reader,
232     lldb::InputReaderAction notification,
233     const char *bytes,
234     size_t bytes_len
235 )
236 {
237     CommandObjectExpression *cmd_object_expr = (CommandObjectExpression *) baton;
238     bool batch_mode = reader.GetDebugger().GetCommandInterpreter().GetBatchCommandMode();
239 
240     switch (notification)
241     {
242     case eInputReaderActivate:
243         if (!batch_mode)
244         {
245             StreamSP async_strm_sp(reader.GetDebugger().GetAsyncOutputStream());
246             if (async_strm_sp)
247             {
248                 async_strm_sp->PutCString("Enter expressions, then terminate with an empty line to evaluate:\n");
249                 async_strm_sp->Flush();
250             }
251         }
252         // Fall through
253     case eInputReaderReactivate:
254         break;
255 
256     case eInputReaderDeactivate:
257         break;
258 
259     case eInputReaderAsynchronousOutputWritten:
260         break;
261 
262     case eInputReaderGotToken:
263         ++cmd_object_expr->m_expr_line_count;
264         if (bytes && bytes_len)
265         {
266             cmd_object_expr->m_expr_lines.append (bytes, bytes_len + 1);
267         }
268 
269         if (bytes_len == 0)
270             reader.SetIsDone(true);
271         break;
272 
273     case eInputReaderInterrupt:
274         cmd_object_expr->m_expr_lines.clear();
275         reader.SetIsDone (true);
276         if (!batch_mode)
277         {
278             StreamSP async_strm_sp (reader.GetDebugger().GetAsyncOutputStream());
279             if (async_strm_sp)
280             {
281                 async_strm_sp->PutCString("Expression evaluation cancelled.\n");
282                 async_strm_sp->Flush();
283             }
284         }
285         break;
286 
287     case eInputReaderEndOfFile:
288         reader.SetIsDone (true);
289         break;
290 
291     case eInputReaderDone:
292 		if (cmd_object_expr->m_expr_lines.size() > 0)
293         {
294             StreamSP output_stream = reader.GetDebugger().GetAsyncOutputStream();
295             StreamSP error_stream = reader.GetDebugger().GetAsyncErrorStream();
296             cmd_object_expr->EvaluateExpression (cmd_object_expr->m_expr_lines.c_str(),
297                                                  output_stream.get(),
298                                                  error_stream.get());
299             output_stream->Flush();
300             error_stream->Flush();
301         }
302         break;
303     }
304 
305     return bytes_len;
306 }
307 
308 bool
309 CommandObjectExpression::EvaluateExpression
310 (
311     const char *expr,
312     Stream *output_stream,
313     Stream *error_stream,
314     CommandReturnObject *result
315 )
316 {
317     // Don't use m_exe_ctx as this might be called asynchronously
318     // after the command object DoExecute has finished when doing
319     // multi-line expression that use an input reader...
320     ExecutionContext exe_ctx (m_interpreter.GetExecutionContext());
321 
322     Target *target = exe_ctx.GetTargetPtr();
323 
324     if (!target)
325         target = Host::GetDummyTarget(m_interpreter.GetDebugger()).get();
326 
327     if (target)
328     {
329         lldb::ValueObjectSP result_valobj_sp;
330 
331         ExecutionResults exe_results;
332 
333         bool keep_in_memory = true;
334 
335         EvaluateExpressionOptions options;
336         options.SetCoerceToId(m_varobj_options.use_objc)
337         .SetUnwindOnError(m_command_options.unwind_on_error)
338         .SetIgnoreBreakpoints (m_command_options.ignore_breakpoints)
339         .SetKeepInMemory(keep_in_memory)
340         .SetUseDynamic(m_varobj_options.use_dynamic)
341         .SetRunOthers(m_command_options.try_all_threads)
342         .SetTimeoutUsec(m_command_options.timeout);
343 
344         exe_results = target->EvaluateExpression (expr,
345                                                   exe_ctx.GetFramePtr(),
346                                                   result_valobj_sp,
347                                                   options);
348 
349         if ((exe_results == eExecutionInterrupted && !m_command_options.unwind_on_error)
350             ||(exe_results == eExecutionHitBreakpoint && !m_command_options.ignore_breakpoints))
351         {
352             uint32_t start_frame = 0;
353             uint32_t num_frames = 1;
354             uint32_t num_frames_with_source = 0;
355             Thread *thread = exe_ctx.GetThreadPtr();
356             if (thread)
357             {
358                 thread->GetStatus (result->GetOutputStream(),
359                                    start_frame,
360                                    num_frames,
361                                    num_frames_with_source);
362             }
363             else
364             {
365                 Process *process = exe_ctx.GetProcessPtr();
366                 if (process)
367                 {
368                     bool only_threads_with_stop_reason = true;
369                     process->GetThreadStatus (result->GetOutputStream(),
370                                               only_threads_with_stop_reason,
371                                               start_frame,
372                                               num_frames,
373                                               num_frames_with_source);
374                 }
375             }
376         }
377 
378         if (result_valobj_sp)
379         {
380             Format format = m_format_options.GetFormat();
381 
382             if (result_valobj_sp->GetError().Success())
383             {
384                 if (format != eFormatVoid)
385                 {
386                     if (format != eFormatDefault)
387                         result_valobj_sp->SetFormat (format);
388 
389                     ValueObject::DumpValueObjectOptions options;
390                     options.SetMaximumPointerDepth(m_varobj_options.ptr_depth);
391                     if (m_varobj_options.use_objc)
392                         options.SetShowSummary(false);
393                     else
394                         options.SetOmitSummaryDepth(m_varobj_options.no_summary_depth);
395                     options.SetMaximumDepth(m_varobj_options.max_depth)
396                            .SetShowTypes(m_varobj_options.show_types)
397                            .SetShowLocation(m_varobj_options.show_location)
398                            .SetUseObjectiveC(m_varobj_options.use_objc)
399                            .SetUseDynamicType(m_varobj_options.use_dynamic)
400                            .SetUseSyntheticValue(m_varobj_options.use_synth)
401                            .SetFlatOutput(m_varobj_options.flat_output)
402                            .SetIgnoreCap(m_varobj_options.ignore_cap)
403                            .SetFormat(format)
404                            .SetHideRootType(m_varobj_options.use_objc)
405                            .SetHideName(m_varobj_options.use_objc)
406                            .SetHideValue(m_varobj_options.use_objc);
407 
408                     if (m_varobj_options.be_raw)
409                         options.SetRawDisplay(true);
410 
411                     ValueObject::DumpValueObject (*(output_stream),
412                                                   result_valobj_sp.get(),   // Variable object to dump
413                                                   options);
414                     if (result)
415                         result->SetStatus (eReturnStatusSuccessFinishResult);
416                 }
417             }
418             else
419             {
420                 if (result_valobj_sp->GetError().GetError() == ClangUserExpression::kNoResult)
421                 {
422                     if (format != eFormatVoid && m_interpreter.GetDebugger().GetNotifyVoid())
423                     {
424                         error_stream->PutCString("(void)\n");
425                     }
426 
427                     if (result)
428                         result->SetStatus (eReturnStatusSuccessFinishResult);
429                 }
430                 else
431                 {
432                     const char *error_cstr = result_valobj_sp->GetError().AsCString();
433                     if (error_cstr && error_cstr[0])
434                     {
435                         const size_t error_cstr_len = strlen (error_cstr);
436                         const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n';
437                         if (strstr(error_cstr, "error:") != error_cstr)
438                             error_stream->PutCString ("error: ");
439                         error_stream->Write(error_cstr, error_cstr_len);
440                         if (!ends_with_newline)
441                             error_stream->EOL();
442                     }
443                     else
444                     {
445                         error_stream->PutCString ("error: unknown error\n");
446                     }
447 
448                     if (result)
449                         result->SetStatus (eReturnStatusFailed);
450                 }
451             }
452         }
453     }
454     else
455     {
456         error_stream->Printf ("error: invalid execution context for expression\n");
457         return false;
458     }
459 
460     return true;
461 }
462 
463 bool
464 CommandObjectExpression::DoExecute
465 (
466     const char *command,
467     CommandReturnObject &result
468 )
469 {
470     m_option_group.NotifyOptionParsingStarting();
471 
472     const char * expr = NULL;
473 
474     if (command[0] == '\0')
475     {
476         m_expr_lines.clear();
477         m_expr_line_count = 0;
478 
479         InputReaderSP reader_sp (new InputReader(m_interpreter.GetDebugger()));
480         if (reader_sp)
481         {
482             Error err (reader_sp->Initialize (CommandObjectExpression::MultiLineExpressionCallback,
483                                               this,                         // baton
484                                               eInputReaderGranularityLine,  // token size, to pass to callback function
485                                               NULL,                         // end token
486                                               NULL,                         // prompt
487                                               true));                       // echo input
488             if (err.Success())
489             {
490                 m_interpreter.GetDebugger().PushInputReader (reader_sp);
491                 result.SetStatus (eReturnStatusSuccessFinishNoResult);
492             }
493             else
494             {
495                 result.AppendError (err.AsCString());
496                 result.SetStatus (eReturnStatusFailed);
497             }
498         }
499         else
500         {
501             result.AppendError("out of memory");
502             result.SetStatus (eReturnStatusFailed);
503         }
504         return result.Succeeded();
505     }
506 
507     if (command[0] == '-')
508     {
509         // We have some options and these options MUST end with --.
510         const char *end_options = NULL;
511         const char *s = command;
512         while (s && s[0])
513         {
514             end_options = ::strstr (s, "--");
515             if (end_options)
516             {
517                 end_options += 2; // Get past the "--"
518                 if (::isspace (end_options[0]))
519                 {
520                     expr = end_options;
521                     while (::isspace (*expr))
522                         ++expr;
523                     break;
524                 }
525             }
526             s = end_options;
527         }
528 
529         if (end_options)
530         {
531             Args args (command, end_options - command);
532             if (!ParseOptions (args, result))
533                 return false;
534 
535             Error error (m_option_group.NotifyOptionParsingFinished());
536             if (error.Fail())
537             {
538                 result.AppendError (error.AsCString());
539                 result.SetStatus (eReturnStatusFailed);
540                 return false;
541             }
542         }
543     }
544 
545     if (expr == NULL)
546         expr = command;
547 
548     if (EvaluateExpression (expr, &(result.GetOutputStream()), &(result.GetErrorStream()), &result))
549         return true;
550 
551     result.SetStatus (eReturnStatusFailed);
552     return false;
553 }
554 
555