xref: /llvm-project/lldb/source/Commands/CommandObjectExpression.cpp (revision 3fe71581743ceb838b113ee728e6de7f7ee8d25d)
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 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/ADT/StringRef.h"
15 
16 // Project includes
17 #include "CommandObjectExpression.h"
18 #include "lldb/Core/Value.h"
19 #include "lldb/Core/ValueObjectVariable.h"
20 #include "lldb/DataFormatters/ValueObjectPrinter.h"
21 #include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h"
22 #include "lldb/Expression/UserExpression.h"
23 #include "lldb/Expression/DWARFExpression.h"
24 #include "lldb/Expression/REPL.h"
25 #include "lldb/Host/Host.h"
26 #include "lldb/Host/StringConvert.h"
27 #include "lldb/Core/Debugger.h"
28 #include "lldb/Interpreter/CommandInterpreter.h"
29 #include "lldb/Interpreter/CommandReturnObject.h"
30 #include "lldb/Target/Language.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 
38 using namespace lldb;
39 using namespace lldb_private;
40 
41 CommandObjectExpression::CommandOptions::CommandOptions () :
42     OptionGroup()
43 {
44 }
45 
46 CommandObjectExpression::CommandOptions::~CommandOptions() = default;
47 
48 static OptionEnumValueElement g_description_verbosity_type[] =
49 {
50     { eLanguageRuntimeDescriptionDisplayVerbosityCompact,      "compact",       "Only show the description string"},
51     { eLanguageRuntimeDescriptionDisplayVerbosityFull,         "full",          "Show the full output, including persistent variable's name and type"},
52     { 0, nullptr, nullptr }
53 };
54 
55 OptionDefinition
56 CommandObjectExpression::CommandOptions::g_option_table[] =
57 {
58     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "all-threads",        'a', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeBoolean,    "Should we run all threads if the execution doesn't complete on one thread."},
59     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "ignore-breakpoints", 'i', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeBoolean,    "Ignore breakpoint hits while running expressions"},
60     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "timeout",            't', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeUnsignedInteger,  "Timeout value (in microseconds) for running the expression."},
61     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "unwind-on-error",    'u', OptionParser::eRequiredArgument, nullptr, nullptr, 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)."},
62     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "debug",              'g', OptionParser::eNoArgument      , nullptr, nullptr, 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)."},
63     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "language",           'l', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeLanguage,   "Specifies the Language to use when parsing the expression.  If not set the target.language setting is used." },
64     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "apply-fixits",       'X', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeLanguage,   "If true, simple FixIt hints will be automatically applied to the expression." },
65     { LLDB_OPT_SET_1, false, "description-verbosity", 'v', OptionParser::eOptionalArgument, nullptr, g_description_verbosity_type, 0, eArgTypeDescriptionVerbosity,        "How verbose should the output of this expression be, if the object description is asked for."},
66     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "top-level",          'p', OptionParser::eNoArgument      , NULL, NULL, 0, eArgTypeNone,       "Interpret the expression as top-level definitions rather than code to be immediately executed."},
67     { LLDB_OPT_SET_1 | LLDB_OPT_SET_2, false, "allow-jit",          'j', OptionParser::eRequiredArgument, nullptr, nullptr, 0, eArgTypeBoolean,    "Controls whether the expression can fall back to being JITted if it's not supported by the interpreter (defaults to true)."}
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 
116     case 'j':
117         {
118             bool success;
119             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
120             if (success)
121                 allow_jit = tmp_value;
122             else
123                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
124             break;
125         }
126 
127     case 't':
128         {
129             bool success;
130             uint32_t result;
131             result = StringConvert::ToUInt32(option_arg, 0, 0, &success);
132             if (success)
133                 timeout = result;
134             else
135                 error.SetErrorStringWithFormat ("invalid timeout setting \"%s\"", option_arg);
136         }
137         break;
138 
139     case 'u':
140         {
141             bool success;
142             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
143             if (success)
144                 unwind_on_error = tmp_value;
145             else
146                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
147             break;
148         }
149 
150     case 'v':
151         if (!option_arg)
152         {
153             m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull;
154             break;
155         }
156         m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity) Args::StringToOptionEnum(option_arg, g_option_table[option_idx].enum_values, 0, error);
157         if (!error.Success())
158             error.SetErrorStringWithFormat ("unrecognized value for description-verbosity '%s'", option_arg);
159         break;
160 
161     case 'g':
162         debug = true;
163         unwind_on_error = false;
164         ignore_breakpoints = false;
165         break;
166 
167     case 'p':
168         top_level = true;
169         break;
170 
171     case 'X':
172         {
173             bool success;
174             bool tmp_value = Args::StringToBoolean(option_arg, true, &success);
175             if (success)
176                 auto_apply_fixits = tmp_value ? eLazyBoolYes : eLazyBoolNo;
177             else
178                 error.SetErrorStringWithFormat("could not convert \"%s\" to a boolean value.", option_arg);
179             break;
180         }
181 
182     default:
183         error.SetErrorStringWithFormat("invalid short option character '%c'", short_option);
184         break;
185     }
186 
187     return error;
188 }
189 
190 void
191 CommandObjectExpression::CommandOptions::OptionParsingStarting (CommandInterpreter &interpreter)
192 {
193     Process *process = interpreter.GetExecutionContext().GetProcessPtr();
194     if (process != nullptr)
195     {
196         ignore_breakpoints = process->GetIgnoreBreakpointsInExpressions();
197         unwind_on_error    = process->GetUnwindOnErrorInExpressions();
198     }
199     else
200     {
201         ignore_breakpoints = true;
202         unwind_on_error = true;
203     }
204 
205     show_summary = true;
206     try_all_threads = true;
207     timeout = 0;
208     debug = false;
209     language = eLanguageTypeUnknown;
210     m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact;
211     auto_apply_fixits = eLazyBoolCalculate;
212     top_level = false;
213     allow_jit = true;
214 }
215 
216 const OptionDefinition*
217 CommandObjectExpression::CommandOptions::GetDefinitions ()
218 {
219     return g_option_table;
220 }
221 
222 CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) :
223     CommandObjectRaw(interpreter,
224                      "expression",
225                      "Evaluate an expression in the current program context, using user defined variables and variables currently in scope.",
226                      nullptr,
227                      eCommandProcessMustBePaused | eCommandTryTargetAPILock),
228     IOHandlerDelegate (IOHandlerDelegate::Completion::Expression),
229     m_option_group (interpreter),
230     m_format_options (eFormatDefault),
231     m_repl_option (LLDB_OPT_SET_1, false, "repl", 'r', "Drop into REPL", false, true),
232     m_command_options (),
233     m_expr_line_count (0),
234     m_expr_lines ()
235 {
236     SetHelpLong(
237 R"(
238 Timeouts:
239 
240 )" "    If the expression can be evaluated statically (without running code) then it will be.  \
241 Otherwise, by default the expression will run on the current thread with a short timeout: \
242 currently .25 seconds.  If it doesn't return in that time, the evaluation will be interrupted \
243 and resumed with all threads running.  You can use the -a option to disable retrying on all \
244 threads.  You can use the -t option to set a shorter timeout." R"(
245 
246 User defined variables:
247 
248 )" "    You can define your own variables for convenience or to be used in subsequent expressions.  \
249 You define them the same way you would define variables in C.  If the first character of \
250 your user defined variable is a $, then the variable's value will be available in future \
251 expressions, otherwise it will just be available in the current expression." R"(
252 
253 Continuing evaluation after a breakpoint:
254 
255 )" "    If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \
256 you are done with your investigation, you can either remove the expression execution frames \
257 from the stack with \"thread return -x\" or if you are still interested in the expression result \
258 you can issue the \"continue\" command and the expression evaluation will complete and the \
259 expression result will be available using the \"thread.completed-expression\" key in the thread \
260 format." R"(
261 
262 Examples:
263 
264     expr my_struct->a = my_array[3]
265     expr -f bin -- (index * 8) + 5
266     expr unsigned int $foo = 5
267     expr char c[] = \"foo\"; c[0])"
268     );
269 
270     CommandArgumentEntry arg;
271     CommandArgumentData expression_arg;
272 
273     // Define the first (and only) variant of this arg.
274     expression_arg.arg_type = eArgTypeExpression;
275     expression_arg.arg_repetition = eArgRepeatPlain;
276 
277     // There is only one variant this argument could be; put it into the argument entry.
278     arg.push_back (expression_arg);
279 
280     // Push the data for the first argument into the m_arguments vector.
281     m_arguments.push_back (arg);
282 
283     // Add the "--format" and "--gdb-format"
284     m_option_group.Append (&m_format_options, OptionGroupFormat::OPTION_GROUP_FORMAT | OptionGroupFormat::OPTION_GROUP_GDB_FMT, LLDB_OPT_SET_1);
285     m_option_group.Append (&m_command_options);
286     m_option_group.Append (&m_varobj_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
287     m_option_group.Append (&m_repl_option, LLDB_OPT_SET_ALL, LLDB_OPT_SET_3);
288     m_option_group.Finalize();
289 }
290 
291 CommandObjectExpression::~CommandObjectExpression() = default;
292 
293 Options *
294 CommandObjectExpression::GetOptions ()
295 {
296     return &m_option_group;
297 }
298 
299 static lldb_private::Error
300 CanBeUsedForElementCountPrinting (ValueObject& valobj)
301 {
302     CompilerType type(valobj.GetCompilerType());
303     CompilerType pointee;
304     if (!type.IsPointerType(&pointee))
305         return Error("as it does not refer to a pointer");
306     if (pointee.IsVoidType())
307         return Error("as it refers to a pointer to void");
308     return Error();
309 }
310 
311 bool
312 CommandObjectExpression::EvaluateExpression(const char *expr,
313                                             Stream *output_stream,
314                                             Stream *error_stream,
315                                             CommandReturnObject *result)
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 = GetDummyTarget();
326 
327     if (target)
328     {
329         lldb::ValueObjectSP result_valobj_sp;
330         bool keep_in_memory = true;
331         StackFrame *frame = exe_ctx.GetFramePtr();
332 
333         EvaluateExpressionOptions options;
334         options.SetCoerceToId(m_varobj_options.use_objc);
335         options.SetUnwindOnError(m_command_options.unwind_on_error);
336         options.SetIgnoreBreakpoints (m_command_options.ignore_breakpoints);
337         options.SetKeepInMemory(keep_in_memory);
338         options.SetUseDynamic(m_varobj_options.use_dynamic);
339         options.SetTryAllThreads(m_command_options.try_all_threads);
340         options.SetDebug(m_command_options.debug);
341         options.SetLanguage(m_command_options.language);
342         options.SetExecutionPolicy(m_command_options.allow_jit ?
343             EvaluateExpressionOptions::default_execution_policy :
344             lldb_private::eExecutionPolicyNever);
345 
346         bool auto_apply_fixits;
347         if (m_command_options.auto_apply_fixits == eLazyBoolCalculate)
348             auto_apply_fixits = target->GetEnableAutoApplyFixIts();
349         else
350             auto_apply_fixits = m_command_options.auto_apply_fixits == eLazyBoolYes ? true : false;
351 
352         options.SetAutoApplyFixIts(auto_apply_fixits);
353 
354         if (m_command_options.top_level)
355             options.SetExecutionPolicy(eExecutionPolicyTopLevel);
356 
357         // If there is any chance we are going to stop and want to see
358         // what went wrong with our expression, we should generate debug info
359         if (!m_command_options.ignore_breakpoints ||
360             !m_command_options.unwind_on_error)
361             options.SetGenerateDebugInfo(true);
362 
363         if (m_command_options.timeout > 0)
364             options.SetTimeoutUsec(m_command_options.timeout);
365         else
366             options.SetTimeoutUsec(0);
367 
368         ExpressionResults success = target->EvaluateExpression(expr, frame, result_valobj_sp, options, &m_fixed_expression);
369 
370         // We only tell you about the FixIt if we applied it.  The compiler errors will suggest the FixIt if it parsed.
371         if (error_stream && !m_fixed_expression.empty() && target->GetEnableNotifyAboutFixIts())
372         {
373             if (success == eExpressionCompleted)
374                 error_stream->Printf ("  Fixit applied, fixed expression was: \n    %s\n", m_fixed_expression.c_str());
375         }
376 
377         if (result_valobj_sp)
378         {
379             Format format = m_format_options.GetFormat();
380 
381             if (result_valobj_sp->GetError().Success())
382             {
383                 if (format != eFormatVoid)
384                 {
385                     if (format != eFormatDefault)
386                         result_valobj_sp->SetFormat (format);
387 
388                     if (m_varobj_options.elem_count > 0)
389                     {
390                         Error error(CanBeUsedForElementCountPrinting(*result_valobj_sp));
391                         if (error.Fail())
392                         {
393                             result->AppendErrorWithFormat("expression cannot be used with --element-count %s\n", error.AsCString(""));
394                             result->SetStatus(eReturnStatusFailed);
395                             return false;
396                         }
397                     }
398 
399                     DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(m_command_options.m_verbosity,format));
400                     options.SetVariableFormatDisplayLanguage(result_valobj_sp->GetPreferredDisplayLanguage());
401 
402                     result_valobj_sp->Dump(*output_stream,options);
403 
404                     if (result)
405                         result->SetStatus (eReturnStatusSuccessFinishResult);
406                 }
407             }
408             else
409             {
410                 if (result_valobj_sp->GetError().GetError() == UserExpression::kNoResult)
411                 {
412                     if (format != eFormatVoid && m_interpreter.GetDebugger().GetNotifyVoid())
413                     {
414                         error_stream->PutCString("(void)\n");
415                     }
416 
417                     if (result)
418                         result->SetStatus (eReturnStatusSuccessFinishResult);
419                 }
420                 else
421                 {
422                     const char *error_cstr = result_valobj_sp->GetError().AsCString();
423                     if (error_cstr && error_cstr[0])
424                     {
425                         const size_t error_cstr_len = strlen (error_cstr);
426                         const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n';
427                         if (strstr(error_cstr, "error:") != error_cstr)
428                             error_stream->PutCString ("error: ");
429                         error_stream->Write(error_cstr, error_cstr_len);
430                         if (!ends_with_newline)
431                             error_stream->EOL();
432                     }
433                     else
434                     {
435                         error_stream->PutCString ("error: unknown error\n");
436                     }
437 
438                     if (result)
439                         result->SetStatus (eReturnStatusFailed);
440                 }
441             }
442         }
443     }
444     else
445     {
446         error_stream->Printf ("error: invalid execution context for expression\n");
447         return false;
448     }
449 
450     return true;
451 }
452 
453 void
454 CommandObjectExpression::IOHandlerInputComplete (IOHandler &io_handler, std::string &line)
455 {
456     io_handler.SetIsDone(true);
457 //    StreamSP output_stream = io_handler.GetDebugger().GetAsyncOutputStream();
458 //    StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream();
459     StreamFileSP output_sp(io_handler.GetOutputStreamFile());
460     StreamFileSP error_sp(io_handler.GetErrorStreamFile());
461 
462     EvaluateExpression (line.c_str(),
463                         output_sp.get(),
464                         error_sp.get());
465     if (output_sp)
466         output_sp->Flush();
467     if (error_sp)
468         error_sp->Flush();
469 }
470 
471 bool
472 CommandObjectExpression::IOHandlerIsInputComplete (IOHandler &io_handler,
473                                                    StringList &lines)
474 {
475     // An empty lines is used to indicate the end of input
476     const size_t num_lines = lines.GetSize();
477     if (num_lines > 0 && lines[num_lines - 1].empty())
478     {
479         // Remove the last empty line from "lines" so it doesn't appear
480         // in our resulting input and return true to indicate we are done
481         // getting lines
482         lines.PopBack();
483         return true;
484     }
485     return false;
486 }
487 
488 void
489 CommandObjectExpression::GetMultilineExpression ()
490 {
491     m_expr_lines.clear();
492     m_expr_line_count = 0;
493 
494     Debugger &debugger = GetCommandInterpreter().GetDebugger();
495     bool color_prompt = debugger.GetUseColor();
496     const bool multiple_lines = true; // Get multiple lines
497     IOHandlerSP io_handler_sp(new IOHandlerEditline(debugger,
498                                                     IOHandler::Type::Expression,
499                                                     "lldb-expr",      // Name of input reader for history
500                                                     nullptr,          // No prompt
501                                                     nullptr,          // Continuation prompt
502                                                     multiple_lines,
503                                                     color_prompt,
504                                                     1,                // Show line numbers starting at 1
505                                                     *this));
506 
507     StreamFileSP output_sp(io_handler_sp->GetOutputStreamFile());
508     if (output_sp)
509     {
510         output_sp->PutCString("Enter expressions, then terminate with an empty line to evaluate:\n");
511         output_sp->Flush();
512     }
513     debugger.PushIOHandler(io_handler_sp);
514 }
515 
516 bool
517 CommandObjectExpression::DoExecute(const char *command,
518                                    CommandReturnObject &result)
519 {
520     m_fixed_expression.clear();
521     m_option_group.NotifyOptionParsingStarting();
522 
523     const char * expr = nullptr;
524 
525     if (command[0] == '\0')
526     {
527         GetMultilineExpression ();
528         return result.Succeeded();
529     }
530 
531     if (command[0] == '-')
532     {
533         // We have some options and these options MUST end with --.
534         const char *end_options = nullptr;
535         const char *s = command;
536         while (s && s[0])
537         {
538             end_options = ::strstr (s, "--");
539             if (end_options)
540             {
541                 end_options += 2; // Get past the "--"
542                 if (::isspace (end_options[0]))
543                 {
544                     expr = end_options;
545                     while (::isspace (*expr))
546                         ++expr;
547                     break;
548                 }
549             }
550             s = end_options;
551         }
552 
553         if (end_options)
554         {
555             Args args (llvm::StringRef(command, end_options - command));
556             if (!ParseOptions (args, result))
557                 return false;
558 
559             Error error (m_option_group.NotifyOptionParsingFinished());
560             if (error.Fail())
561             {
562                 result.AppendError (error.AsCString());
563                 result.SetStatus (eReturnStatusFailed);
564                 return false;
565             }
566 
567             if (m_repl_option.GetOptionValue().GetCurrentValue())
568             {
569                 Target *target = m_interpreter.GetExecutionContext().GetTargetPtr();
570                 if (target)
571                 {
572                     // Drop into REPL
573                     m_expr_lines.clear();
574                     m_expr_line_count = 0;
575 
576                     Debugger &debugger = target->GetDebugger();
577 
578                     // Check if the LLDB command interpreter is sitting on top of a REPL that
579                     // launched it...
580                     if (debugger.CheckTopIOHandlerTypes(IOHandler::Type::CommandInterpreter, IOHandler::Type::REPL))
581                     {
582                         // the LLDB command interpreter is sitting on top of a REPL that launched it,
583                         // so just say the command interpreter is done and fall back to the existing REPL
584                         m_interpreter.GetIOHandler(false)->SetIsDone(true);
585                     }
586                     else
587                     {
588                         // We are launching the REPL on top of the current LLDB command interpreter,
589                         // so just push one
590                         bool initialize = false;
591                         Error repl_error;
592                         REPLSP repl_sp (target->GetREPL(repl_error, m_command_options.language, nullptr, false));
593 
594                         if (!repl_sp)
595                         {
596                             initialize = true;
597                             repl_sp = target->GetREPL(repl_error, m_command_options.language, nullptr, true);
598                             if (!repl_error.Success())
599                             {
600                                 result.SetError(repl_error);
601                                 return result.Succeeded();
602                             }
603                         }
604 
605                         if (repl_sp)
606                         {
607                             if (initialize)
608                             {
609                                 repl_sp->SetCommandOptions(m_command_options);
610                                 repl_sp->SetFormatOptions(m_format_options);
611                                 repl_sp->SetValueObjectDisplayOptions(m_varobj_options);
612                             }
613 
614                             IOHandlerSP io_handler_sp (repl_sp->GetIOHandler());
615 
616                             io_handler_sp->SetIsDone(false);
617 
618                             debugger.PushIOHandler(io_handler_sp);
619                         }
620                         else
621                         {
622                             repl_error.SetErrorStringWithFormat("Couldn't create a REPL for %s", Language::GetNameForLanguageType(m_command_options.language));
623                             result.SetError(repl_error);
624                             return result.Succeeded();
625                         }
626                     }
627                 }
628             }
629             // No expression following options
630             else if (expr == nullptr || expr[0] == '\0')
631             {
632                 GetMultilineExpression ();
633                 return result.Succeeded();
634             }
635         }
636     }
637 
638     if (expr == nullptr)
639         expr = command;
640 
641     if (EvaluateExpression (expr, &(result.GetOutputStream()), &(result.GetErrorStream()), &result))
642     {
643         Target *target = m_interpreter.GetExecutionContext().GetTargetPtr();
644         if (!m_fixed_expression.empty() && target->GetEnableNotifyAboutFixIts())
645         {
646             CommandHistory &history = m_interpreter.GetCommandHistory();
647             // FIXME: Can we figure out what the user actually typed (e.g. some alias for expr???)
648             // If we can it would be nice to show that.
649             std::string fixed_command("expression ");
650             if (expr == command)
651                 fixed_command.append(m_fixed_expression);
652             else
653             {
654                 // Add in any options that might have been in the original command:
655                 fixed_command.append(command, expr - command);
656                 fixed_command.append(m_fixed_expression);
657             }
658             history.AppendString(fixed_command);
659         }
660         return true;
661     }
662 
663     result.SetStatus (eReturnStatusFailed);
664     return false;
665 }
666