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/Core/Value.h"
17 #include "lldb/Core/ValueObjectVariable.h"
18 #include "lldb/DataFormatters/ValueObjectPrinter.h"
19 #include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h"
20 #include "lldb/Expression/UserExpression.h"
21 #include "lldb/Expression/DWARFExpression.h"
22 #include "lldb/Host/Host.h"
23 #include "lldb/Host/StringConvert.h"
24 #include "lldb/Core/Debugger.h"
25 #include "lldb/Interpreter/CommandInterpreter.h"
26 #include "lldb/Interpreter/CommandReturnObject.h"
27 #include "lldb/Target/Language.h"
28 #include "lldb/Symbol/ObjectFile.h"
29 #include "lldb/Symbol/Variable.h"
30 #include "lldb/Target/Process.h"
31 #include "lldb/Target/StackFrame.h"
32 #include "lldb/Target/Target.h"
33 #include "lldb/Target/Thread.h"
34 #include "llvm/ADT/STLExtras.h"
35 #include "llvm/ADT/StringRef.h"
36 
37 using namespace lldb;
38 using namespace lldb_private;
39 
40 CommandObjectExpression::CommandOptions::CommandOptions () :
41     OptionGroup()
42 {
43 }
44 
45 
46 CommandObjectExpression::CommandOptions::~CommandOptions ()
47 {
48 }
49 
50 static OptionEnumValueElement g_description_verbosity_type[] =
51 {
52     { eLanguageRuntimeDescriptionDisplayVerbosityCompact,      "compact",       "Only show the description string"},
53     { eLanguageRuntimeDescriptionDisplayVerbosityFull,         "full",          "Show the full output, including persistent variable's name and type"},
54     { 0, NULL, NULL }
55 };
56 
57 OptionDefinition
58 CommandObjectExpression::CommandOptions::g_option_table[] =
59 {
60     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "all-threads",        'a', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean,    "Should we run all threads if the execution doesn't complete on one thread."},
61     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "ignore-breakpoints", 'i', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean,    "Ignore breakpoint hits while running expressions"},
62     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "timeout",            't', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeUnsignedInteger,  "Timeout value (in microseconds) for running the expression."},
63     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "unwind-on-error",    'u', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean,    "Clean up program state if the expression causes a crash, or raises a signal.  Note, unlike gdb hitting a breakpoint is controlled by another option (-i)."},
64     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "debug",              'g', OptionParser::eNoArgument      , NULL, NULL, 0, eArgTypeNone,       "When specified, debug the JIT code by setting a breakpoint on the first instruction and forcing breakpoints to not be ignored (-i0) and no unwinding to happen on error (-u0)."},
65     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "language",           'l', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeLanguage,   "Specifies the Language to use when parsing the expression.  If not set the target.language setting is used." },
66     { LLDB_OPT_SET_1, false, "description-verbosity", 'v', OptionParser::eOptionalArgument, NULL, g_description_verbosity_type, 0, eArgTypeDescriptionVerbosity,        "How verbose should the output of this expression be, if the object description is asked for."},
67 };
68 
69 
70 uint32_t
71 CommandObjectExpression::CommandOptions::GetNumDefinitions ()
72 {
73     return llvm::array_lengthof(g_option_table);
74 }
75 
76 Error
77 CommandObjectExpression::CommandOptions::SetOptionValue (CommandInterpreter &interpreter,
78                                                          uint32_t option_idx,
79                                                          const char *option_arg)
80 {
81     Error error;
82 
83     const int short_option = g_option_table[option_idx].short_option;
84 
85     switch (short_option)
86     {
87     case 'l':
88         language = Language::GetLanguageTypeFromString (option_arg);
89         if (language == eLanguageTypeUnknown)
90             error.SetErrorStringWithFormat ("unknown language type: '%s' for expression", option_arg);
91         break;
92 
93     case 'a':
94         {
95             bool success;
96             bool result;
97             result = Args::StringToBoolean(option_arg, true, &success);
98             if (!success)
99                 error.SetErrorStringWithFormat("invalid all-threads value setting: \"%s\"", option_arg);
100             else
101                 try_all_threads = result;
102         }
103         break;
104 
105     case 'i':
106         {
107             bool success;
108             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
109             if (success)
110                 ignore_breakpoints = tmp_value;
111             else
112                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
113             break;
114         }
115     case 't':
116         {
117             bool success;
118             uint32_t result;
119             result = StringConvert::ToUInt32(option_arg, 0, 0, &success);
120             if (success)
121                 timeout = result;
122             else
123                 error.SetErrorStringWithFormat ("invalid timeout setting \"%s\"", option_arg);
124         }
125         break;
126 
127     case 'u':
128         {
129             bool success;
130             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
131             if (success)
132                 unwind_on_error = tmp_value;
133             else
134                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
135             break;
136         }
137 
138     case 'v':
139         if (!option_arg)
140         {
141             m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull;
142             break;
143         }
144         m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity) Args::StringToOptionEnum(option_arg, g_option_table[option_idx].enum_values, 0, error);
145         if (!error.Success())
146             error.SetErrorStringWithFormat ("unrecognized value for description-verbosity '%s'", option_arg);
147         break;
148 
149     case 'g':
150         debug = true;
151         unwind_on_error = false;
152         ignore_breakpoints = false;
153         break;
154 
155     default:
156         error.SetErrorStringWithFormat("invalid short option character '%c'", short_option);
157         break;
158     }
159 
160     return error;
161 }
162 
163 void
164 CommandObjectExpression::CommandOptions::OptionParsingStarting (CommandInterpreter &interpreter)
165 {
166     Process *process = interpreter.GetExecutionContext().GetProcessPtr();
167     if (process != NULL)
168     {
169         ignore_breakpoints = process->GetIgnoreBreakpointsInExpressions();
170         unwind_on_error    = process->GetUnwindOnErrorInExpressions();
171     }
172     else
173     {
174         ignore_breakpoints = true;
175         unwind_on_error = true;
176     }
177 
178     show_summary = true;
179     try_all_threads = true;
180     timeout = 0;
181     debug = false;
182     language = eLanguageTypeUnknown;
183     m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact;
184 }
185 
186 const OptionDefinition*
187 CommandObjectExpression::CommandOptions::GetDefinitions ()
188 {
189     return g_option_table;
190 }
191 
192 CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) :
193     CommandObjectRaw (interpreter,
194                       "expression",
195                       "Evaluate an expression in the current program context, using user defined variables and variables currently in scope.",
196                       NULL,
197                       eCommandProcessMustBePaused | eCommandTryTargetAPILock),
198     IOHandlerDelegate (IOHandlerDelegate::Completion::Expression),
199     m_option_group (interpreter),
200     m_format_options (eFormatDefault),
201     m_command_options (),
202     m_expr_line_count (0),
203     m_expr_lines ()
204 {
205     SetHelpLong(
206 R"(
207 Timeouts:
208 
209 )" "    If the expression can be evaluated statically (without running code) then it will be.  \
210 Otherwise, by default the expression will run on the current thread with a short timeout: \
211 currently .25 seconds.  If it doesn't return in that time, the evaluation will be interrupted \
212 and resumed with all threads running.  You can use the -a option to disable retrying on all \
213 threads.  You can use the -t option to set a shorter timeout." R"(
214 
215 User defined variables:
216 
217 )" "    You can define your own variables for convenience or to be used in subsequent expressions.  \
218 You define them the same way you would define variables in C.  If the first character of \
219 your user defined variable is a $, then the variable's value will be available in future \
220 expressions, otherwise it will just be available in the current expression." R"(
221 
222 Continuing evaluation after a breakpoint:
223 
224 )" "    If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \
225 you are done with your investigation, you can either remove the expression execution frames \
226 from the stack with \"thread return -x\" or if you are still interested in the expression result \
227 you can issue the \"continue\" command and the expression evaluation will complete and the \
228 expression result will be available using the \"thread.completed-expression\" key in the thread \
229 format." R"(
230 
231 Examples:
232 
233     expr my_struct->a = my_array[3]
234     expr -f bin -- (index * 8) + 5
235     expr unsigned int $foo = 5
236     expr char c[] = \"foo\"; c[0])"
237     );
238 
239     CommandArgumentEntry arg;
240     CommandArgumentData expression_arg;
241 
242     // Define the first (and only) variant of this arg.
243     expression_arg.arg_type = eArgTypeExpression;
244     expression_arg.arg_repetition = eArgRepeatPlain;
245 
246     // There is only one variant this argument could be; put it into the argument entry.
247     arg.push_back (expression_arg);
248 
249     // Push the data for the first argument into the m_arguments vector.
250     m_arguments.push_back (arg);
251 
252     // Add the "--format" and "--gdb-format"
253     m_option_group.Append (&m_format_options, OptionGroupFormat::OPTION_GROUP_FORMAT | OptionGroupFormat::OPTION_GROUP_GDB_FMT, LLDB_OPT_SET_1);
254     m_option_group.Append (&m_command_options);
255     m_option_group.Append (&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
256     m_option_group.Finalize();
257 }
258 
259 CommandObjectExpression::~CommandObjectExpression ()
260 {
261 }
262 
263 Options *
264 CommandObjectExpression::GetOptions ()
265 {
266     return &m_option_group;
267 }
268 
269 bool
270 CommandObjectExpression::EvaluateExpression
271 (
272     const char *expr,
273     Stream *output_stream,
274     Stream *error_stream,
275     CommandReturnObject *result
276 )
277 {
278     // Don't use m_exe_ctx as this might be called asynchronously
279     // after the command object DoExecute has finished when doing
280     // multi-line expression that use an input reader...
281     ExecutionContext exe_ctx (m_interpreter.GetExecutionContext());
282 
283     Target *target = exe_ctx.GetTargetPtr();
284 
285     if (!target)
286         target = GetDummyTarget();
287 
288     if (target)
289     {
290         lldb::ValueObjectSP result_valobj_sp;
291         bool keep_in_memory = true;
292         StackFrame *frame = exe_ctx.GetFramePtr();
293 
294         EvaluateExpressionOptions options;
295         options.SetCoerceToId(m_varobj_options.use_objc);
296         options.SetUnwindOnError(m_command_options.unwind_on_error);
297         options.SetIgnoreBreakpoints (m_command_options.ignore_breakpoints);
298         options.SetKeepInMemory(keep_in_memory);
299         options.SetUseDynamic(m_varobj_options.use_dynamic);
300         options.SetTryAllThreads(m_command_options.try_all_threads);
301         options.SetDebug(m_command_options.debug);
302 
303         // If the language was not specified in the expression command,
304         // set it to the language in the target's properties if
305         // specified, else default to the langage for the frame.
306         if (m_command_options.language != eLanguageTypeUnknown)
307             options.SetLanguage(m_command_options.language);
308         else if (target->GetLanguage() != eLanguageTypeUnknown)
309             options.SetLanguage(target->GetLanguage());
310         else if (frame)
311             options.SetLanguage(frame->GetLanguage());
312 
313         // If there is any chance we are going to stop and want to see
314         // what went wrong with our expression, we should generate debug info
315         if (!m_command_options.ignore_breakpoints ||
316             !m_command_options.unwind_on_error)
317             options.SetGenerateDebugInfo(true);
318 
319         if (m_command_options.timeout > 0)
320             options.SetTimeoutUsec(m_command_options.timeout);
321         else
322             options.SetTimeoutUsec(0);
323 
324         target->EvaluateExpression(expr, frame, result_valobj_sp, options);
325 
326         if (result_valobj_sp)
327         {
328             Format format = m_format_options.GetFormat();
329 
330             if (result_valobj_sp->GetError().Success())
331             {
332                 if (format != eFormatVoid)
333                 {
334                     if (format != eFormatDefault)
335                         result_valobj_sp->SetFormat (format);
336 
337                     DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(m_command_options.m_verbosity,format));
338 
339                     result_valobj_sp->Dump(*output_stream,options);
340 
341                     if (result)
342                         result->SetStatus (eReturnStatusSuccessFinishResult);
343                 }
344             }
345             else
346             {
347                 if (result_valobj_sp->GetError().GetError() == UserExpression::kNoResult)
348                 {
349                     if (format != eFormatVoid && m_interpreter.GetDebugger().GetNotifyVoid())
350                     {
351                         error_stream->PutCString("(void)\n");
352                     }
353 
354                     if (result)
355                         result->SetStatus (eReturnStatusSuccessFinishResult);
356                 }
357                 else
358                 {
359                     const char *error_cstr = result_valobj_sp->GetError().AsCString();
360                     if (error_cstr && error_cstr[0])
361                     {
362                         const size_t error_cstr_len = strlen (error_cstr);
363                         const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n';
364                         if (strstr(error_cstr, "error:") != error_cstr)
365                             error_stream->PutCString ("error: ");
366                         error_stream->Write(error_cstr, error_cstr_len);
367                         if (!ends_with_newline)
368                             error_stream->EOL();
369                     }
370                     else
371                     {
372                         error_stream->PutCString ("error: unknown error\n");
373                     }
374 
375                     if (result)
376                         result->SetStatus (eReturnStatusFailed);
377                 }
378             }
379         }
380     }
381     else
382     {
383         error_stream->Printf ("error: invalid execution context for expression\n");
384         return false;
385     }
386 
387     return true;
388 }
389 
390 void
391 CommandObjectExpression::IOHandlerInputComplete (IOHandler &io_handler, std::string &line)
392 {
393     io_handler.SetIsDone(true);
394 //    StreamSP output_stream = io_handler.GetDebugger().GetAsyncOutputStream();
395 //    StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream();
396     StreamFileSP output_sp(io_handler.GetOutputStreamFile());
397     StreamFileSP error_sp(io_handler.GetErrorStreamFile());
398 
399     EvaluateExpression (line.c_str(),
400                         output_sp.get(),
401                         error_sp.get());
402     if (output_sp)
403         output_sp->Flush();
404     if (error_sp)
405         error_sp->Flush();
406 }
407 
408 LineStatus
409 CommandObjectExpression::IOHandlerLinesUpdated (IOHandler &io_handler,
410                                                 StringList &lines,
411                                                 uint32_t line_idx,
412                                                 Error &error)
413 {
414     if (line_idx == UINT32_MAX)
415     {
416         // Remove the last line from "lines" so it doesn't appear
417         // in our final expression
418         lines.PopBack();
419         error.Clear();
420         return LineStatus::Done;
421     }
422     else if (line_idx + 1 == lines.GetSize())
423     {
424         // The last line was edited, if this line is empty, then we are done
425         // getting our multiple lines.
426         if (lines[line_idx].empty())
427             return LineStatus::Done;
428     }
429     return LineStatus::Success;
430 }
431 
432 void
433 CommandObjectExpression::GetMultilineExpression ()
434 {
435     m_expr_lines.clear();
436     m_expr_line_count = 0;
437 
438     Debugger &debugger = GetCommandInterpreter().GetDebugger();
439     bool color_prompt = debugger.GetUseColor();
440     const bool multiple_lines = true; // Get multiple lines
441     IOHandlerSP io_handler_sp (new IOHandlerEditline (debugger,
442                                                       IOHandler::Type::Expression,
443                                                       "lldb-expr",      // Name of input reader for history
444                                                       NULL,             // No prompt
445                                                       NULL,             // Continuation prompt
446                                                       multiple_lines,
447                                                       color_prompt,
448                                                       1,                // Show line numbers starting at 1
449                                                       *this));
450 
451     StreamFileSP output_sp(io_handler_sp->GetOutputStreamFile());
452     if (output_sp)
453     {
454         output_sp->PutCString("Enter expressions, then terminate with an empty line to evaluate:\n");
455         output_sp->Flush();
456     }
457     debugger.PushIOHandler(io_handler_sp);
458 }
459 
460 bool
461 CommandObjectExpression::DoExecute
462 (
463     const char *command,
464     CommandReturnObject &result
465 )
466 {
467     m_option_group.NotifyOptionParsingStarting();
468 
469     const char * expr = NULL;
470 
471     if (command[0] == '\0')
472     {
473         GetMultilineExpression ();
474         return result.Succeeded();
475     }
476 
477     if (command[0] == '-')
478     {
479         // We have some options and these options MUST end with --.
480         const char *end_options = NULL;
481         const char *s = command;
482         while (s && s[0])
483         {
484             end_options = ::strstr (s, "--");
485             if (end_options)
486             {
487                 end_options += 2; // Get past the "--"
488                 if (::isspace (end_options[0]))
489                 {
490                     expr = end_options;
491                     while (::isspace (*expr))
492                         ++expr;
493                     break;
494                 }
495             }
496             s = end_options;
497         }
498 
499         if (end_options)
500         {
501             Args args (llvm::StringRef(command, end_options - command));
502             if (!ParseOptions (args, result))
503                 return false;
504 
505             Error error (m_option_group.NotifyOptionParsingFinished());
506             if (error.Fail())
507             {
508                 result.AppendError (error.AsCString());
509                 result.SetStatus (eReturnStatusFailed);
510                 return false;
511             }
512 
513             // No expression following options
514             if (expr == NULL || expr[0] == '\0')
515             {
516                 GetMultilineExpression ();
517                 return result.Succeeded();
518             }
519         }
520     }
521 
522     if (expr == NULL)
523         expr = command;
524 
525     if (EvaluateExpression (expr, &(result.GetOutputStream()), &(result.GetErrorStream()), &result))
526         return true;
527 
528     result.SetStatus (eReturnStatusFailed);
529     return false;
530 }
531 
532