xref: /llvm-project/lldb/source/Commands/CommandObjectExpression.cpp (revision 3bfdaa2a4735262a1d246ced4db906a3531ba330)
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 "CommandObjectExpression.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Interpreter/Args.h"
17 #include "lldb/Core/Value.h"
18 #include "lldb/Core/InputReader.h"
19 #include "lldb/Core/ValueObjectVariable.h"
20 #include "lldb/Expression/ClangExpressionVariable.h"
21 #include "lldb/Expression/ClangUserExpression.h"
22 #include "lldb/Expression/ClangFunction.h"
23 #include "lldb/Expression/DWARFExpression.h"
24 #include "lldb/Host/Host.h"
25 #include "lldb/Core/Debugger.h"
26 #include "lldb/Interpreter/CommandInterpreter.h"
27 #include "lldb/Interpreter/CommandReturnObject.h"
28 #include "lldb/Target/ObjCLanguageRuntime.h"
29 #include "lldb/Symbol/ObjectFile.h"
30 #include "lldb/Symbol/Variable.h"
31 #include "lldb/Target/Process.h"
32 #include "lldb/Target/StackFrame.h"
33 #include "lldb/Target/Target.h"
34 #include "lldb/Target/Thread.h"
35 #include "llvm/ADT/StringRef.h"
36 
37 using namespace lldb;
38 using namespace lldb_private;
39 
40 CommandObjectExpression::CommandOptions::CommandOptions (CommandInterpreter &interpreter) :
41     Options(interpreter)
42 {
43     // Keep only one place to reset the values to their defaults
44     OptionParsingStarting();
45 }
46 
47 
48 CommandObjectExpression::CommandOptions::~CommandOptions ()
49 {
50 }
51 
52 Error
53 CommandObjectExpression::CommandOptions::SetOptionValue (uint32_t option_idx, const char *option_arg)
54 {
55     Error error;
56 
57     char short_option = (char) m_getopt_table[option_idx].val;
58 
59     switch (short_option)
60     {
61       //case 'l':
62       //if (language.SetLanguageFromCString (option_arg) == false)
63       //{
64       //    error.SetErrorStringWithFormat("Invalid language option argument '%s'.\n", option_arg);
65       //}
66       //break;
67 
68     case 'g':
69         debug = true;
70         break;
71 
72     case 'f':
73         error = Args::StringToFormat(option_arg, format, NULL);
74         break;
75 
76     case 'o':
77         print_object = true;
78         break;
79 
80     case 'd':
81         {
82             bool success;
83             bool result;
84             result = Args::StringToBoolean(option_arg, true, &success);
85             if (!success)
86                 error.SetErrorStringWithFormat("Invalid dynamic value setting: \"%s\".\n", option_arg);
87             else
88             {
89                 if (result)
90                     use_dynamic = eLazyBoolYes;
91                 else
92                     use_dynamic = eLazyBoolNo;
93             }
94         }
95         break;
96 
97     case 'u':
98         {
99             bool success;
100             unwind_on_error = Args::StringToBoolean(option_arg, true, &success);
101             if (!success)
102                 error.SetErrorStringWithFormat("Could not convert \"%s\" to a boolean value.", option_arg);
103             break;
104         }
105     default:
106         error.SetErrorStringWithFormat("Invalid short option character '%c'.\n", short_option);
107         break;
108     }
109 
110     return error;
111 }
112 
113 void
114 CommandObjectExpression::CommandOptions::OptionParsingStarting ()
115 {
116     //language.Clear();
117     debug = false;
118     format = eFormatDefault;
119     print_object = false;
120     use_dynamic = eLazyBoolCalculate;
121     unwind_on_error = true;
122     show_types = true;
123     show_summary = true;
124 }
125 
126 const OptionDefinition*
127 CommandObjectExpression::CommandOptions::GetDefinitions ()
128 {
129     return g_option_table;
130 }
131 
132 CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) :
133     CommandObject (interpreter,
134                    "expression",
135                    "Evaluate a C/ObjC/C++ expression in the current program context, using variables currently in scope.",
136                    NULL),
137     m_options (interpreter),
138     m_expr_line_count (0),
139     m_expr_lines ()
140 {
141   SetHelpLong(
142 "Examples: \n\
143 \n\
144    expr my_struct->a = my_array[3] \n\
145    expr -f bin -- (index * 8) + 5 \n\
146    expr char c[] = \"foo\"; c[0]\n");
147 
148     CommandArgumentEntry arg;
149     CommandArgumentData expression_arg;
150 
151     // Define the first (and only) variant of this arg.
152     expression_arg.arg_type = eArgTypeExpression;
153     expression_arg.arg_repetition = eArgRepeatPlain;
154 
155     // There is only one variant this argument could be; put it into the argument entry.
156     arg.push_back (expression_arg);
157 
158     // Push the data for the first argument into the m_arguments vector.
159     m_arguments.push_back (arg);
160 }
161 
162 CommandObjectExpression::~CommandObjectExpression ()
163 {
164 }
165 
166 Options *
167 CommandObjectExpression::GetOptions ()
168 {
169     return &m_options;
170 }
171 
172 
173 bool
174 CommandObjectExpression::Execute
175 (
176     Args& command,
177     CommandReturnObject &result
178 )
179 {
180     return false;
181 }
182 
183 
184 size_t
185 CommandObjectExpression::MultiLineExpressionCallback
186 (
187     void *baton,
188     InputReader &reader,
189     lldb::InputReaderAction notification,
190     const char *bytes,
191     size_t bytes_len
192 )
193 {
194     CommandObjectExpression *cmd_object_expr = (CommandObjectExpression *) baton;
195     bool batch_mode = reader.GetDebugger().GetCommandInterpreter().GetBatchCommandMode();
196 
197     switch (notification)
198     {
199     case eInputReaderActivate:
200         if (!batch_mode)
201         {
202             StreamSP async_strm_sp(reader.GetDebugger().GetAsyncOutputStream());
203             if (async_strm_sp)
204             {
205                 async_strm_sp->PutCString("Enter expressions, then terminate with an empty line to evaluate:\n");
206                 async_strm_sp->Flush();
207             }
208         }
209         // Fall through
210     case eInputReaderReactivate:
211         break;
212 
213     case eInputReaderDeactivate:
214         break;
215 
216     case eInputReaderAsynchronousOutputWritten:
217         break;
218 
219     case eInputReaderGotToken:
220         ++cmd_object_expr->m_expr_line_count;
221         if (bytes && bytes_len)
222         {
223             cmd_object_expr->m_expr_lines.append (bytes, bytes_len + 1);
224         }
225 
226         if (bytes_len == 0)
227             reader.SetIsDone(true);
228         break;
229 
230     case eInputReaderInterrupt:
231         cmd_object_expr->m_expr_lines.clear();
232         reader.SetIsDone (true);
233         if (!batch_mode)
234         {
235             StreamSP async_strm_sp (reader.GetDebugger().GetAsyncOutputStream());
236             if (async_strm_sp)
237             {
238                 async_strm_sp->PutCString("Expression evaluation cancelled.\n");
239                 async_strm_sp->Flush();
240             }
241         }
242         break;
243 
244     case eInputReaderEndOfFile:
245         reader.SetIsDone (true);
246         break;
247 
248     case eInputReaderDone:
249 		if (cmd_object_expr->m_expr_lines.size() > 0)
250         {
251             StreamSP output_stream = reader.GetDebugger().GetAsyncOutputStream();
252             StreamSP error_stream = reader.GetDebugger().GetAsyncErrorStream();
253             cmd_object_expr->EvaluateExpression (cmd_object_expr->m_expr_lines.c_str(),
254                                                  output_stream.get(),
255                                                  error_stream.get());
256             output_stream->Flush();
257             error_stream->Flush();
258         }
259         break;
260     }
261 
262     return bytes_len;
263 }
264 
265 bool
266 CommandObjectExpression::EvaluateExpression
267 (
268     const char *expr,
269     Stream *output_stream,
270     Stream *error_stream,
271     CommandReturnObject *result
272 )
273 {
274     if (m_exe_ctx.target)
275     {
276         lldb::ValueObjectSP result_valobj_sp;
277 
278         ExecutionResults exe_results;
279 
280         bool keep_in_memory = true;
281         lldb::DynamicValueType use_dynamic;
282         // If use dynamic is not set, get it from the target:
283         switch (m_options.use_dynamic)
284         {
285         case eLazyBoolCalculate:
286             use_dynamic = m_exe_ctx.target->GetPreferDynamicValue();
287             break;
288         case eLazyBoolYes:
289             use_dynamic = lldb::eDynamicCanRunTarget;
290             break;
291         case eLazyBoolNo:
292             use_dynamic = lldb::eNoDynamicValues;
293             break;
294         }
295 
296         exe_results = m_exe_ctx.target->EvaluateExpression(expr,
297                                                            m_exe_ctx.frame,
298                                                            eExecutionPolicyOnlyWhenNeeded,
299                                                            m_options.unwind_on_error,
300                                                            keep_in_memory,
301                                                            use_dynamic,
302                                                            result_valobj_sp);
303 
304         if (exe_results == eExecutionInterrupted && !m_options.unwind_on_error)
305         {
306             uint32_t start_frame = 0;
307             uint32_t num_frames = 1;
308             uint32_t num_frames_with_source = 0;
309             if (m_exe_ctx.thread)
310             {
311                 m_exe_ctx.thread->GetStatus (result->GetOutputStream(),
312                                              start_frame,
313                                              num_frames,
314                                              num_frames_with_source);
315             }
316             else if (m_exe_ctx.process)
317             {
318                 bool only_threads_with_stop_reason = true;
319                 m_exe_ctx.process->GetThreadStatus (result->GetOutputStream(),
320                                                     only_threads_with_stop_reason,
321                                                     start_frame,
322                                                     num_frames,
323                                                     num_frames_with_source);
324             }
325         }
326 
327         if (result_valobj_sp)
328         {
329             if (result_valobj_sp->GetError().Success())
330             {
331                 if (m_options.format != eFormatDefault)
332                     result_valobj_sp->SetFormat (m_options.format);
333 
334                 ValueObject::DumpValueObject (*(output_stream),
335                                               result_valobj_sp.get(),   // Variable object to dump
336                                               result_valobj_sp->GetName().GetCString(),// Root object name
337                                               0,                        // Pointer depth to traverse (zero means stop at pointers)
338                                               0,                        // Current depth, this is the top most, so zero...
339                                               UINT32_MAX,               // Max depth to go when dumping concrete types, dump everything...
340                                               m_options.show_types,     // Show types when dumping?
341                                               false,                    // Show locations of variables, no since this is a host address which we don't care to see
342                                               m_options.print_object,   // Print the objective C object?
343                                               use_dynamic,
344                                               true,                     // Use synthetic children if available
345                                               true,                     // Scope is already checked. Const results are always in scope.
346                                               false,                    // Don't flatten output
347                                               0,                        // Always use summaries (you might want an option --no-summary like there is for frame variable)
348                                               false);                   // Do not show more children than settings allow
349                 if (result)
350                     result->SetStatus (eReturnStatusSuccessFinishResult);
351             }
352             else
353             {
354                 if (result_valobj_sp->GetError().GetError() == ClangUserExpression::kNoResult)
355                 {
356                     error_stream->PutCString("<no result>\n");
357 
358                     if (result)
359                         result->SetStatus (eReturnStatusSuccessFinishResult);
360                 }
361                 else
362                 {
363                     const char *error_cstr = result_valobj_sp->GetError().AsCString();
364                     if (error_cstr && error_cstr[0])
365                     {
366                         int error_cstr_len = strlen (error_cstr);
367                         const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n';
368                         if (strstr(error_cstr, "error:") != error_cstr)
369                             error_stream->PutCString ("error: ");
370                         error_stream->Write(error_cstr, error_cstr_len);
371                         if (!ends_with_newline)
372                             error_stream->EOL();
373                     }
374                     else
375                     {
376                         error_stream->PutCString ("error: unknown error\n");
377                     }
378 
379                     if (result)
380                         result->SetStatus (eReturnStatusFailed);
381                 }
382             }
383         }
384     }
385     else
386     {
387         error_stream->Printf ("error: invalid execution context for expression\n");
388         return false;
389     }
390 
391     return true;
392 }
393 
394 bool
395 CommandObjectExpression::ExecuteRawCommandString
396 (
397     const char *command,
398     CommandReturnObject &result
399 )
400 {
401     m_exe_ctx = m_interpreter.GetExecutionContext();
402 
403     m_options.NotifyOptionParsingStarting();
404 
405     const char * expr = NULL;
406 
407     if (command[0] == '\0')
408     {
409         m_expr_lines.clear();
410         m_expr_line_count = 0;
411 
412         InputReaderSP reader_sp (new InputReader(m_interpreter.GetDebugger()));
413         if (reader_sp)
414         {
415             Error err (reader_sp->Initialize (CommandObjectExpression::MultiLineExpressionCallback,
416                                               this,                         // baton
417                                               eInputReaderGranularityLine,  // token size, to pass to callback function
418                                               NULL,                         // end token
419                                               NULL,                         // prompt
420                                               true));                       // echo input
421             if (err.Success())
422             {
423                 m_interpreter.GetDebugger().PushInputReader (reader_sp);
424                 result.SetStatus (eReturnStatusSuccessFinishNoResult);
425             }
426             else
427             {
428                 result.AppendError (err.AsCString());
429                 result.SetStatus (eReturnStatusFailed);
430             }
431         }
432         else
433         {
434             result.AppendError("out of memory");
435             result.SetStatus (eReturnStatusFailed);
436         }
437         return result.Succeeded();
438     }
439 
440     if (command[0] == '-')
441     {
442         // We have some options and these options MUST end with --.
443         const char *end_options = NULL;
444         const char *s = command;
445         while (s && s[0])
446         {
447             end_options = ::strstr (s, "--");
448             if (end_options)
449             {
450                 end_options += 2; // Get past the "--"
451                 if (::isspace (end_options[0]))
452                 {
453                     expr = end_options;
454                     while (::isspace (*expr))
455                         ++expr;
456                     break;
457                 }
458             }
459             s = end_options;
460         }
461 
462         if (end_options)
463         {
464             Args args (command, end_options - command);
465             if (!ParseOptions (args, result))
466                 return false;
467 
468             Error error (m_options.NotifyOptionParsingFinished());
469             if (error.Fail())
470             {
471                 result.AppendError (error.AsCString());
472                 result.SetStatus (eReturnStatusFailed);
473                 return false;
474             }
475         }
476     }
477 
478     if (expr == NULL)
479         expr = command;
480 
481     if (EvaluateExpression (expr, &(result.GetOutputStream()), &(result.GetErrorStream()), &result))
482         return true;
483 
484     result.SetStatus (eReturnStatusFailed);
485     return false;
486 }
487 
488 OptionDefinition
489 CommandObjectExpression::CommandOptions::g_option_table[] =
490 {
491 //{ LLDB_OPT_SET_ALL, false, "language",   'l', required_argument, NULL, 0, "[c|c++|objc|objc++]",          "Sets the language to use when parsing the expression."},
492 //{ LLDB_OPT_SET_1, false, "format",     'f', required_argument, NULL, 0, "[ [bool|b] | [bin] | [char|c] | [oct|o] | [dec|i|d|u] | [hex|x] | [float|f] | [cstr|s] ]",  "Specify the format that the expression output should use."},
493 { LLDB_OPT_SET_1,   false, "format",             'f', required_argument, NULL, 0, eArgTypeExprFormat, "Specify the format that the expression output should use."},
494 { LLDB_OPT_SET_2,   false, "object-description", 'o', no_argument,       NULL, 0, eArgTypeNone,       "Print the object description of the value resulting from the expression."},
495 { LLDB_OPT_SET_2,   false, "dynamic-value",      'd', required_argument, NULL, 0, eArgTypeBoolean,    "Upcast the value resulting from the expression to its dynamic type if available."},
496 { LLDB_OPT_SET_ALL, false, "unwind-on-error",    'u', required_argument, NULL, 0, eArgTypeBoolean,    "Clean up program state if the expression causes a crash, breakpoint hit or signal."},
497 { LLDB_OPT_SET_ALL, false, "debug",              'g', no_argument,       NULL, 0, eArgTypeNone,       "Enable verbose debug logging of the expression parsing and evaluation."},
498 { 0,                false, NULL,                 0,   0,                 NULL, 0, eArgTypeNone,       NULL }
499 };
500 
501