xref: /llvm-project/lldb/source/Commands/CommandObjectExpression.cpp (revision 15663c530ed23d15c8122649ab331d25b64b4f63)
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 "lldb/Expression/ClangExpressionVariable.h"
20 #include "lldb/Expression/ClangUserExpression.h"
21 #include "lldb/Expression/ClangFunction.h"
22 #include "lldb/Expression/DWARFExpression.h"
23 #include "lldb/Host/Host.h"
24 #include "lldb/Host/StringConvert.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/STLExtras.h"
36 #include "llvm/ADT/StringRef.h"
37 
38 using namespace lldb;
39 using namespace lldb_private;
40 
41 CommandObjectExpression::CommandOptions::CommandOptions () :
42     OptionGroup()
43 {
44 }
45 
46 
47 CommandObjectExpression::CommandOptions::~CommandOptions ()
48 {
49 }
50 
51 static OptionEnumValueElement g_description_verbosity_type[] =
52 {
53     { eLanguageRuntimeDescriptionDisplayVerbosityCompact,      "compact",       "Only show the description string"},
54     { eLanguageRuntimeDescriptionDisplayVerbosityFull,         "full",          "Show the full output, including persistent variable's name and type"},
55     { 0, NULL, NULL }
56 };
57 
58 OptionDefinition
59 CommandObjectExpression::CommandOptions::g_option_table[] =
60 {
61     { 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."},
62     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "ignore-breakpoints", 'i', OptionParser::eRequiredArgument, NULL, NULL, 0, eArgTypeBoolean,    "Ignore breakpoint hits while running expressions"},
63     { 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."},
64     { 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)."},
65     { 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)."},
66     { 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." },
67     { 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."},
68 };
69 
70 
71 uint32_t
72 CommandObjectExpression::CommandOptions::GetNumDefinitions ()
73 {
74     return llvm::array_lengthof(g_option_table);
75 }
76 
77 Error
78 CommandObjectExpression::CommandOptions::SetOptionValue (CommandInterpreter &interpreter,
79                                                          uint32_t option_idx,
80                                                          const char *option_arg)
81 {
82     Error error;
83 
84     const int short_option = g_option_table[option_idx].short_option;
85 
86     switch (short_option)
87     {
88     case 'l':
89         language = LanguageRuntime::GetLanguageTypeFromString (option_arg);
90         if (language == eLanguageTypeUnknown)
91             error.SetErrorStringWithFormat ("unknown language type: '%s' for expression", option_arg);
92         break;
93 
94     case 'a':
95         {
96             bool success;
97             bool result;
98             result = Args::StringToBoolean(option_arg, true, &success);
99             if (!success)
100                 error.SetErrorStringWithFormat("invalid all-threads value setting: \"%s\"", option_arg);
101             else
102                 try_all_threads = result;
103         }
104         break;
105 
106     case 'i':
107         {
108             bool success;
109             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
110             if (success)
111                 ignore_breakpoints = tmp_value;
112             else
113                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
114             break;
115         }
116     case 't':
117         {
118             bool success;
119             uint32_t result;
120             result = StringConvert::ToUInt32(option_arg, 0, 0, &success);
121             if (success)
122                 timeout = result;
123             else
124                 error.SetErrorStringWithFormat ("invalid timeout setting \"%s\"", option_arg);
125         }
126         break;
127 
128     case 'u':
129         {
130             bool success;
131             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
132             if (success)
133                 unwind_on_error = tmp_value;
134             else
135                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
136             break;
137         }
138 
139     case 'v':
140         if (!option_arg)
141         {
142             m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull;
143             break;
144         }
145         m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity) Args::StringToOptionEnum(option_arg, g_option_table[option_idx].enum_values, 0, error);
146         if (!error.Success())
147             error.SetErrorStringWithFormat ("unrecognized value for description-verbosity '%s'", option_arg);
148         break;
149 
150     case 'g':
151         debug = true;
152         unwind_on_error = false;
153         ignore_breakpoints = false;
154         break;
155 
156     default:
157         error.SetErrorStringWithFormat("invalid short option character '%c'", short_option);
158         break;
159     }
160 
161     return error;
162 }
163 
164 void
165 CommandObjectExpression::CommandOptions::OptionParsingStarting (CommandInterpreter &interpreter)
166 {
167     Process *process = interpreter.GetExecutionContext().GetProcessPtr();
168     if (process != NULL)
169     {
170         ignore_breakpoints = process->GetIgnoreBreakpointsInExpressions();
171         unwind_on_error    = process->GetUnwindOnErrorInExpressions();
172     }
173     else
174     {
175         ignore_breakpoints = true;
176         unwind_on_error = true;
177     }
178 
179     show_summary = true;
180     try_all_threads = true;
181     timeout = 0;
182     debug = false;
183     language = eLanguageTypeUnknown;
184     m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact;
185 }
186 
187 const OptionDefinition*
188 CommandObjectExpression::CommandOptions::GetDefinitions ()
189 {
190     return g_option_table;
191 }
192 
193 CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) :
194     CommandObjectRaw (interpreter,
195                       "expression",
196                       "Evaluate an expression in the current program context, using user defined variables and variables currently in scope.",
197                       NULL,
198                       eCommandProcessMustBePaused | eCommandTryTargetAPILock),
199     IOHandlerDelegate (IOHandlerDelegate::Completion::Expression),
200     m_option_group (interpreter),
201     m_format_options (eFormatDefault),
202     m_command_options (),
203     m_expr_line_count (0),
204     m_expr_lines ()
205 {
206     SetHelpLong(
207 R"(
208 Timeouts:
209 
210 )" "    If the expression can be evaluated statically (without running code) then it will be.  \
211 Otherwise, by default the expression will run on the current thread with a short timeout: \
212 currently .25 seconds.  If it doesn't return in that time, the evaluation will be interrupted \
213 and resumed with all threads running.  You can use the -a option to disable retrying on all \
214 threads.  You can use the -t option to set a shorter timeout." R"(
215 
216 User defined variables:
217 
218 )" "    You can define your own variables for convenience or to be used in subsequent expressions.  \
219 You define them the same way you would define variables in C.  If the first character of \
220 your user defined variable is a $, then the variable's value will be available in future \
221 expressions, otherwise it will just be available in the current expression." R"(
222 
223 Continuing evaluation after a breakpoint:
224 
225 )" "    If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \
226 you are done with your investigation, you can either remove the expression execution frames \
227 from the stack with \"thread return -x\" or if you are still interested in the expression result \
228 you can issue the \"continue\" command and the expression evaluation will complete and the \
229 expression result will be available using the \"thread.completed-expression\" key in the thread \
230 format." R"(
231 
232 Examples:
233 
234     expr my_struct->a = my_array[3]
235     expr -f bin -- (index * 8) + 5
236     expr unsigned int $foo = 5
237     expr char c[] = \"foo\"; c[0])"
238     );
239 
240     CommandArgumentEntry arg;
241     CommandArgumentData expression_arg;
242 
243     // Define the first (and only) variant of this arg.
244     expression_arg.arg_type = eArgTypeExpression;
245     expression_arg.arg_repetition = eArgRepeatPlain;
246 
247     // There is only one variant this argument could be; put it into the argument entry.
248     arg.push_back (expression_arg);
249 
250     // Push the data for the first argument into the m_arguments vector.
251     m_arguments.push_back (arg);
252 
253     // Add the "--format" and "--gdb-format"
254     m_option_group.Append (&m_format_options, OptionGroupFormat::OPTION_GROUP_FORMAT | OptionGroupFormat::OPTION_GROUP_GDB_FMT, LLDB_OPT_SET_1);
255     m_option_group.Append (&m_command_options);
256     m_option_group.Append (&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
257     m_option_group.Finalize();
258 }
259 
260 CommandObjectExpression::~CommandObjectExpression ()
261 {
262 }
263 
264 Options *
265 CommandObjectExpression::GetOptions ()
266 {
267     return &m_option_group;
268 }
269 
270 bool
271 CommandObjectExpression::EvaluateExpression
272 (
273     const char *expr,
274     Stream *output_stream,
275     Stream *error_stream,
276     CommandReturnObject *result
277 )
278 {
279     // Don't use m_exe_ctx as this might be called asynchronously
280     // after the command object DoExecute has finished when doing
281     // multi-line expression that use an input reader...
282     ExecutionContext exe_ctx (m_interpreter.GetExecutionContext());
283 
284     Target *target = exe_ctx.GetTargetPtr();
285 
286     if (!target)
287         target = GetDummyTarget();
288 
289     if (target)
290     {
291         lldb::ValueObjectSP result_valobj_sp;
292 
293         bool keep_in_memory = true;
294 
295         EvaluateExpressionOptions options;
296         options.SetCoerceToId(m_varobj_options.use_objc);
297         options.SetUnwindOnError(m_command_options.unwind_on_error);
298         options.SetIgnoreBreakpoints (m_command_options.ignore_breakpoints);
299         options.SetKeepInMemory(keep_in_memory);
300         options.SetUseDynamic(m_varobj_options.use_dynamic);
301         options.SetTryAllThreads(m_command_options.try_all_threads);
302         options.SetDebug(m_command_options.debug);
303 
304         // If the language was not specified, set it from target's properties
305         if (m_command_options.language != eLanguageTypeUnknown)
306             options.SetLanguage(m_command_options.language);
307         else
308             options.SetLanguage(target->GetLanguage());
309 
310         // If there is any chance we are going to stop and want to see
311         // what went wrong with our expression, we should generate debug info
312         if (!m_command_options.ignore_breakpoints ||
313             !m_command_options.unwind_on_error)
314             options.SetGenerateDebugInfo(true);
315 
316         if (m_command_options.timeout > 0)
317             options.SetTimeoutUsec(m_command_options.timeout);
318         else
319             options.SetTimeoutUsec(0);
320 
321         target->EvaluateExpression(expr, exe_ctx.GetFramePtr(),
322                                    result_valobj_sp, options);
323 
324         if (result_valobj_sp)
325         {
326             Format format = m_format_options.GetFormat();
327 
328             if (result_valobj_sp->GetError().Success())
329             {
330                 if (format != eFormatVoid)
331                 {
332                     if (format != eFormatDefault)
333                         result_valobj_sp->SetFormat (format);
334 
335                     DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(m_command_options.m_verbosity,format));
336 
337                     result_valobj_sp->Dump(*output_stream,options);
338 
339                     if (result)
340                         result->SetStatus (eReturnStatusSuccessFinishResult);
341                 }
342             }
343             else
344             {
345                 if (result_valobj_sp->GetError().GetError() == ClangUserExpression::kNoResult)
346                 {
347                     if (format != eFormatVoid && m_interpreter.GetDebugger().GetNotifyVoid())
348                     {
349                         error_stream->PutCString("(void)\n");
350                     }
351 
352                     if (result)
353                         result->SetStatus (eReturnStatusSuccessFinishResult);
354                 }
355                 else
356                 {
357                     const char *error_cstr = result_valobj_sp->GetError().AsCString();
358                     if (error_cstr && error_cstr[0])
359                     {
360                         const size_t error_cstr_len = strlen (error_cstr);
361                         const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n';
362                         if (strstr(error_cstr, "error:") != error_cstr)
363                             error_stream->PutCString ("error: ");
364                         error_stream->Write(error_cstr, error_cstr_len);
365                         if (!ends_with_newline)
366                             error_stream->EOL();
367                     }
368                     else
369                     {
370                         error_stream->PutCString ("error: unknown error\n");
371                     }
372 
373                     if (result)
374                         result->SetStatus (eReturnStatusFailed);
375                 }
376             }
377         }
378     }
379     else
380     {
381         error_stream->Printf ("error: invalid execution context for expression\n");
382         return false;
383     }
384 
385     return true;
386 }
387 
388 void
389 CommandObjectExpression::IOHandlerInputComplete (IOHandler &io_handler, std::string &line)
390 {
391     io_handler.SetIsDone(true);
392 //    StreamSP output_stream = io_handler.GetDebugger().GetAsyncOutputStream();
393 //    StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream();
394     StreamFileSP output_sp(io_handler.GetOutputStreamFile());
395     StreamFileSP error_sp(io_handler.GetErrorStreamFile());
396 
397     EvaluateExpression (line.c_str(),
398                         output_sp.get(),
399                         error_sp.get());
400     if (output_sp)
401         output_sp->Flush();
402     if (error_sp)
403         error_sp->Flush();
404 }
405 
406 LineStatus
407 CommandObjectExpression::IOHandlerLinesUpdated (IOHandler &io_handler,
408                                                 StringList &lines,
409                                                 uint32_t line_idx,
410                                                 Error &error)
411 {
412     if (line_idx == UINT32_MAX)
413     {
414         // Remove the last line from "lines" so it doesn't appear
415         // in our final expression
416         lines.PopBack();
417         error.Clear();
418         return LineStatus::Done;
419     }
420     else if (line_idx + 1 == lines.GetSize())
421     {
422         // The last line was edited, if this line is empty, then we are done
423         // getting our multiple lines.
424         if (lines[line_idx].empty())
425             return LineStatus::Done;
426     }
427     return LineStatus::Success;
428 }
429 
430 void
431 CommandObjectExpression::GetMultilineExpression ()
432 {
433     m_expr_lines.clear();
434     m_expr_line_count = 0;
435 
436     Debugger &debugger = GetCommandInterpreter().GetDebugger();
437     bool color_prompt = debugger.GetUseColor();
438     const bool multiple_lines = true; // Get multiple lines
439     IOHandlerSP io_handler_sp (new IOHandlerEditline (debugger,
440                                                       IOHandler::Type::Expression,
441                                                       "lldb-expr",      // Name of input reader for history
442                                                       NULL,             // No prompt
443                                                       NULL,             // Continuation prompt
444                                                       multiple_lines,
445                                                       color_prompt,
446                                                       1,                // Show line numbers starting at 1
447                                                       *this));
448 
449     StreamFileSP output_sp(io_handler_sp->GetOutputStreamFile());
450     if (output_sp)
451     {
452         output_sp->PutCString("Enter expressions, then terminate with an empty line to evaluate:\n");
453         output_sp->Flush();
454     }
455     debugger.PushIOHandler(io_handler_sp);
456 }
457 
458 bool
459 CommandObjectExpression::DoExecute
460 (
461     const char *command,
462     CommandReturnObject &result
463 )
464 {
465     m_option_group.NotifyOptionParsingStarting();
466 
467     const char * expr = NULL;
468 
469     if (command[0] == '\0')
470     {
471         GetMultilineExpression ();
472         return result.Succeeded();
473     }
474 
475     if (command[0] == '-')
476     {
477         // We have some options and these options MUST end with --.
478         const char *end_options = NULL;
479         const char *s = command;
480         while (s && s[0])
481         {
482             end_options = ::strstr (s, "--");
483             if (end_options)
484             {
485                 end_options += 2; // Get past the "--"
486                 if (::isspace (end_options[0]))
487                 {
488                     expr = end_options;
489                     while (::isspace (*expr))
490                         ++expr;
491                     break;
492                 }
493             }
494             s = end_options;
495         }
496 
497         if (end_options)
498         {
499             Args args (llvm::StringRef(command, end_options - command));
500             if (!ParseOptions (args, result))
501                 return false;
502 
503             Error error (m_option_group.NotifyOptionParsingFinished());
504             if (error.Fail())
505             {
506                 result.AppendError (error.AsCString());
507                 result.SetStatus (eReturnStatusFailed);
508                 return false;
509             }
510 
511             // No expression following options
512             if (expr == NULL || expr[0] == '\0')
513             {
514                 GetMultilineExpression ();
515                 return result.Succeeded();
516             }
517         }
518     }
519 
520     if (expr == NULL)
521         expr = command;
522 
523     if (EvaluateExpression (expr, &(result.GetOutputStream()), &(result.GetErrorStream()), &result))
524         return true;
525 
526     result.SetStatus (eReturnStatusFailed);
527     return false;
528 }
529 
530