1 //===-- Options.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/Interpreter/Options.h"
11 
12 // C Includes
13 // C++ Includes
14 #include <algorithm>
15 #include <bitset>
16 #include <set>
17 
18 // Other libraries and framework includes
19 // Project includes
20 #include "lldb/Interpreter/CommandObject.h"
21 #include "lldb/Interpreter/CommandReturnObject.h"
22 #include "lldb/Interpreter/CommandCompletions.h"
23 #include "lldb/Interpreter/CommandInterpreter.h"
24 #include "lldb/Core/StreamString.h"
25 #include "lldb/Target/Target.h"
26 
27 using namespace lldb;
28 using namespace lldb_private;
29 
30 //-------------------------------------------------------------------------
31 // Options
32 //-------------------------------------------------------------------------
33 Options::Options (CommandInterpreter &interpreter) :
34     m_interpreter (interpreter),
35     m_getopt_table ()
36 {
37     BuildValidOptionSets();
38 }
39 
40 Options::~Options ()
41 {
42 }
43 
44 void
45 Options::NotifyOptionParsingStarting ()
46 {
47     m_seen_options.clear();
48     // Let the subclass reset its option values
49     OptionParsingStarting ();
50 }
51 
52 Error
53 Options::NotifyOptionParsingFinished ()
54 {
55     return OptionParsingFinished ();
56 }
57 
58 void
59 Options::OptionSeen (int option_idx)
60 {
61     m_seen_options.insert ((char) option_idx);
62 }
63 
64 // Returns true is set_a is a subset of set_b;  Otherwise returns false.
65 
66 bool
67 Options::IsASubset (const OptionSet& set_a, const OptionSet& set_b)
68 {
69     bool is_a_subset = true;
70     OptionSet::const_iterator pos_a;
71     OptionSet::const_iterator pos_b;
72 
73     // set_a is a subset of set_b if every member of set_a is also a member of set_b
74 
75     for (pos_a = set_a.begin(); pos_a != set_a.end() && is_a_subset; ++pos_a)
76     {
77         pos_b = set_b.find(*pos_a);
78         if (pos_b == set_b.end())
79             is_a_subset = false;
80     }
81 
82     return is_a_subset;
83 }
84 
85 // Returns the set difference set_a - set_b, i.e. { x | ElementOf (x, set_a) && !ElementOf (x, set_b) }
86 
87 size_t
88 Options::OptionsSetDiff (const OptionSet& set_a, const OptionSet& set_b, OptionSet& diffs)
89 {
90     size_t num_diffs = 0;
91     OptionSet::const_iterator pos_a;
92     OptionSet::const_iterator pos_b;
93 
94     for (pos_a = set_a.begin(); pos_a != set_a.end(); ++pos_a)
95     {
96         pos_b = set_b.find(*pos_a);
97         if (pos_b == set_b.end())
98         {
99             ++num_diffs;
100             diffs.insert(*pos_a);
101         }
102     }
103 
104     return num_diffs;
105 }
106 
107 // Returns the union of set_a and set_b.  Does not put duplicate members into the union.
108 
109 void
110 Options::OptionsSetUnion (const OptionSet &set_a, const OptionSet &set_b, OptionSet &union_set)
111 {
112     OptionSet::const_iterator pos;
113     OptionSet::iterator pos_union;
114 
115     // Put all the elements of set_a into the union.
116 
117     for (pos = set_a.begin(); pos != set_a.end(); ++pos)
118         union_set.insert(*pos);
119 
120     // Put all the elements of set_b that are not already there into the union.
121     for (pos = set_b.begin(); pos != set_b.end(); ++pos)
122     {
123         pos_union = union_set.find(*pos);
124         if (pos_union == union_set.end())
125             union_set.insert(*pos);
126     }
127 }
128 
129 bool
130 Options::VerifyOptions (CommandReturnObject &result)
131 {
132     bool options_are_valid = false;
133 
134     int num_levels = GetRequiredOptions().size();
135     if (num_levels)
136     {
137         for (int i = 0; i < num_levels && !options_are_valid; ++i)
138         {
139             // This is the correct set of options if:  1). m_seen_options contains all of m_required_options[i]
140             // (i.e. all the required options at this level are a subset of m_seen_options); AND
141             // 2). { m_seen_options - m_required_options[i] is a subset of m_options_options[i] (i.e. all the rest of
142             // m_seen_options are in the set of optional options at this level.
143 
144             // Check to see if all of m_required_options[i] are a subset of m_seen_options
145             if (IsASubset (GetRequiredOptions()[i], m_seen_options))
146             {
147                 // Construct the set difference: remaining_options = {m_seen_options} - {m_required_options[i]}
148                 OptionSet remaining_options;
149                 OptionsSetDiff (m_seen_options, GetRequiredOptions()[i], remaining_options);
150                 // Check to see if remaining_options is a subset of m_optional_options[i]
151                 if (IsASubset (remaining_options, GetOptionalOptions()[i]))
152                     options_are_valid = true;
153             }
154         }
155     }
156     else
157     {
158         options_are_valid = true;
159     }
160 
161     if (options_are_valid)
162     {
163         result.SetStatus (eReturnStatusSuccessFinishNoResult);
164     }
165     else
166     {
167         result.AppendError ("invalid combination of options for the given command");
168         result.SetStatus (eReturnStatusFailed);
169     }
170 
171     return options_are_valid;
172 }
173 
174 // This is called in the Options constructor, though we could call it lazily if that ends up being
175 // a performance problem.
176 
177 void
178 Options::BuildValidOptionSets ()
179 {
180     // Check to see if we already did this.
181     if (m_required_options.size() != 0)
182         return;
183 
184     // Check to see if there are any options.
185     int num_options = NumCommandOptions ();
186     if (num_options == 0)
187         return;
188 
189     const OptionDefinition *opt_defs = GetDefinitions();
190     m_required_options.resize(1);
191     m_optional_options.resize(1);
192 
193     // First count the number of option sets we've got.  Ignore LLDB_ALL_OPTION_SETS...
194 
195     uint32_t num_option_sets = 0;
196 
197     for (int i = 0; i < num_options; i++)
198     {
199         uint32_t this_usage_mask = opt_defs[i].usage_mask;
200         if (this_usage_mask == LLDB_OPT_SET_ALL)
201         {
202             if (num_option_sets == 0)
203                 num_option_sets = 1;
204         }
205         else
206         {
207             for (int j = 0; j < LLDB_MAX_NUM_OPTION_SETS; j++)
208             {
209                 if (this_usage_mask & (1 << j))
210                 {
211                     if (num_option_sets <= j)
212                         num_option_sets = j + 1;
213                 }
214             }
215         }
216     }
217 
218     if (num_option_sets > 0)
219     {
220         m_required_options.resize(num_option_sets);
221         m_optional_options.resize(num_option_sets);
222 
223         for (int i = 0; i < num_options; ++i)
224         {
225             for (int j = 0; j < num_option_sets; j++)
226             {
227                 if (opt_defs[i].usage_mask & 1 << j)
228                 {
229                     if (opt_defs[i].required)
230                         m_required_options[j].insert(opt_defs[i].short_option);
231                     else
232                         m_optional_options[j].insert(opt_defs[i].short_option);
233                 }
234             }
235         }
236     }
237 }
238 
239 uint32_t
240 Options::NumCommandOptions ()
241 {
242     const OptionDefinition *opt_defs = GetDefinitions ();
243     if (opt_defs == NULL)
244         return 0;
245 
246     int i = 0;
247 
248     if (opt_defs != NULL)
249     {
250         while (opt_defs[i].long_option != NULL)
251             ++i;
252     }
253 
254     return i;
255 }
256 
257 struct option *
258 Options::GetLongOptions ()
259 {
260     // Check to see if this has already been done.
261     if (m_getopt_table.empty())
262     {
263         // Check to see if there are any options.
264         const uint32_t num_options = NumCommandOptions();
265         if (num_options == 0)
266             return NULL;
267 
268         uint32_t i;
269         uint32_t j;
270         const OptionDefinition *opt_defs = GetDefinitions();
271 
272         std::bitset<256> option_seen;
273 
274         m_getopt_table.resize(num_options + 1);
275         for (i = 0, j = 0; i < num_options; ++i)
276         {
277             char short_opt = opt_defs[i].short_option;
278 
279             if (option_seen.test(short_opt) == false)
280             {
281                 m_getopt_table[j].name    = opt_defs[i].long_option;
282                 m_getopt_table[j].has_arg = opt_defs[i].option_has_arg;
283                 m_getopt_table[j].flag    = NULL;
284                 m_getopt_table[j].val     = opt_defs[i].short_option;
285                 option_seen.set(short_opt);
286                 ++j;
287             }
288         }
289 
290         //getopt_long requires a NULL final entry in the table:
291 
292         m_getopt_table[j].name    = NULL;
293         m_getopt_table[j].has_arg = 0;
294         m_getopt_table[j].flag    = NULL;
295         m_getopt_table[j].val     = 0;
296     }
297 
298     if (m_getopt_table.empty())
299         return NULL;
300 
301     return &m_getopt_table.front();
302 }
303 
304 
305 // This function takes INDENT, which tells how many spaces to output at the front of each line; SPACES, which is
306 // a string containing 80 spaces; and TEXT, which is the text that is to be output.   It outputs the text, on
307 // multiple lines if necessary, to RESULT, with INDENT spaces at the front of each line.  It breaks lines on spaces,
308 // tabs or newlines, shortening the line if necessary to not break in the middle of a word.  It assumes that each
309 // output line should contain a maximum of OUTPUT_MAX_COLUMNS characters.
310 
311 
312 void
313 Options::OutputFormattedUsageText
314 (
315     Stream &strm,
316     const char *text,
317     uint32_t output_max_columns
318 )
319 {
320     int len = strlen (text);
321 
322     // Will it all fit on one line?
323 
324     if ((len + strm.GetIndentLevel()) < output_max_columns)
325     {
326         // Output it as a single line.
327         strm.Indent (text);
328         strm.EOL();
329     }
330     else
331     {
332         // We need to break it up into multiple lines.
333 
334         int text_width = output_max_columns - strm.GetIndentLevel() - 1;
335         int start = 0;
336         int end = start;
337         int final_end = strlen (text);
338         int sub_len;
339 
340         while (end < final_end)
341         {
342             // Don't start the 'text' on a space, since we're already outputting the indentation.
343             while ((start < final_end) && (text[start] == ' '))
344                 start++;
345 
346             end = start + text_width;
347             if (end > final_end)
348                 end = final_end;
349             else
350             {
351                 // If we're not at the end of the text, make sure we break the line on white space.
352                 while (end > start
353                        && text[end] != ' ' && text[end] != '\t' && text[end] != '\n')
354                     end--;
355             }
356 
357             sub_len = end - start;
358             if (start != 0)
359                 strm.EOL();
360             strm.Indent();
361             assert (start < final_end);
362             assert (start + sub_len <= final_end);
363             strm.Write(text + start, sub_len);
364             start = end + 1;
365         }
366         strm.EOL();
367     }
368 }
369 
370 bool
371 Options::SupportsLongOption (const char *long_option)
372 {
373     if (long_option && long_option[0])
374     {
375         const OptionDefinition *opt_defs = GetDefinitions ();
376         if (opt_defs)
377         {
378             const char *long_option_name = long_option;
379             if (long_option[0] == '-' && long_option[1] == '-')
380                 long_option_name += 2;
381 
382             for (uint32_t i = 0; opt_defs[i].long_option; ++i)
383             {
384                 if (strcmp(opt_defs[i].long_option, long_option_name) == 0)
385                     return true;
386             }
387         }
388     }
389     return false;
390 }
391 
392 void
393 Options::GenerateOptionUsage
394 (
395     Stream &strm,
396     CommandObject *cmd
397 )
398 {
399     const uint32_t screen_width = m_interpreter.GetDebugger().GetTerminalWidth();
400 
401     const OptionDefinition *opt_defs = GetDefinitions();
402     const uint32_t save_indent_level = strm.GetIndentLevel();
403     const char *name;
404 
405     StreamString arguments_str;
406 
407     if (cmd)
408     {
409         name = cmd->GetCommandName();
410         cmd->GetFormattedCommandArguments (arguments_str);
411     }
412     else
413         name = "";
414 
415     strm.PutCString ("\nCommand Options Usage:\n");
416 
417     strm.IndentMore(2);
418 
419     // First, show each usage level set of options, e.g. <cmd> [options-for-level-0]
420     //                                                   <cmd> [options-for-level-1]
421     //                                                   etc.
422 
423     const uint32_t num_options = NumCommandOptions();
424     if (num_options == 0)
425         return;
426 
427     int num_option_sets = GetRequiredOptions().size();
428 
429     uint32_t i;
430 
431     for (uint32_t opt_set = 0; opt_set < num_option_sets; ++opt_set)
432     {
433         uint32_t opt_set_mask;
434 
435         opt_set_mask = 1 << opt_set;
436         if (opt_set > 0)
437             strm.Printf ("\n");
438         strm.Indent (name);
439 
440         // First go through and print all options that take no arguments as
441         // a single string. If a command has "-a" "-b" and "-c", this will show
442         // up as [-abc]
443 
444         std::set<char> options;
445         std::set<char>::const_iterator options_pos, options_end;
446         bool first;
447         for (i = 0, first = true; i < num_options; ++i)
448         {
449             if (opt_defs[i].usage_mask & opt_set_mask)
450             {
451                 // Add current option to the end of out_stream.
452 
453                 if (opt_defs[i].required == true &&
454                     opt_defs[i].option_has_arg == no_argument)
455                 {
456                     options.insert (opt_defs[i].short_option);
457                 }
458             }
459         }
460 
461         if (options.empty() == false)
462         {
463             // We have some required options with no arguments
464             strm.PutCString(" -");
465             for (i=0; i<2; ++i)
466                 for (options_pos = options.begin(), options_end = options.end();
467                      options_pos != options_end;
468                      ++options_pos)
469                 {
470                     if (i==0 && ::isupper (*options_pos))
471                         continue;
472                     if (i==1 && ::islower (*options_pos))
473                         continue;
474                     strm << *options_pos;
475                 }
476         }
477 
478         for (i = 0, options.clear(); i < num_options; ++i)
479         {
480             if (opt_defs[i].usage_mask & opt_set_mask)
481             {
482                 // Add current option to the end of out_stream.
483 
484                 if (opt_defs[i].required == false &&
485                     opt_defs[i].option_has_arg == no_argument)
486                 {
487                     options.insert (opt_defs[i].short_option);
488                 }
489             }
490         }
491 
492         if (options.empty() == false)
493         {
494             // We have some required options with no arguments
495             strm.PutCString(" [-");
496             for (i=0; i<2; ++i)
497                 for (options_pos = options.begin(), options_end = options.end();
498                      options_pos != options_end;
499                      ++options_pos)
500                 {
501                     if (i==0 && ::isupper (*options_pos))
502                         continue;
503                     if (i==1 && ::islower (*options_pos))
504                         continue;
505                     strm << *options_pos;
506                 }
507             strm.PutChar(']');
508         }
509 
510         // First go through and print the required options (list them up front).
511 
512         for (i = 0; i < num_options; ++i)
513         {
514             if (opt_defs[i].usage_mask & opt_set_mask)
515             {
516                 // Add current option to the end of out_stream.
517                 CommandArgumentType arg_type = opt_defs[i].argument_type;
518 
519                 if (opt_defs[i].required)
520                 {
521                     if (opt_defs[i].option_has_arg == required_argument)
522                     {
523                         strm.Printf (" -%c <%s>",
524                                      opt_defs[i].short_option,
525                                      CommandObject::GetArgumentName (arg_type));
526                     }
527                     else if (opt_defs[i].option_has_arg == optional_argument)
528                     {
529                         strm.Printf (" -%c [<%s>]",
530                                      opt_defs[i].short_option,
531                                      CommandObject::GetArgumentName (arg_type));
532                     }
533                 }
534             }
535         }
536 
537         // Now go through again, and this time only print the optional options.
538 
539         for (i = 0; i < num_options; ++i)
540         {
541             if (opt_defs[i].usage_mask & opt_set_mask)
542             {
543                 // Add current option to the end of out_stream.
544 
545                 CommandArgumentType arg_type = opt_defs[i].argument_type;
546 
547                 if (! opt_defs[i].required)
548                 {
549                     if (opt_defs[i].option_has_arg == required_argument)
550                         strm.Printf (" [-%c <%s>]", opt_defs[i].short_option,
551                                      CommandObject::GetArgumentName (arg_type));
552                     else if (opt_defs[i].option_has_arg == optional_argument)
553                         strm.Printf (" [-%c [<%s>]]", opt_defs[i].short_option,
554                                      CommandObject::GetArgumentName (arg_type));
555                 }
556             }
557         }
558 
559         if (arguments_str.GetSize() > 0)
560         {
561             if (cmd->WantsRawCommandString())
562                 strm.Printf(" --");
563 
564             strm.Printf (" %s", arguments_str.GetData());
565         }
566     }
567 
568     if (cmd->WantsRawCommandString() &&
569         arguments_str.GetSize() > 0)
570     {
571         strm.PutChar('\n');
572         strm.Indent(name);
573         strm.Printf(" %s", arguments_str.GetData());
574     }
575 
576     strm.Printf ("\n\n");
577 
578     // Now print out all the detailed information about the various options:  long form, short form and help text:
579     //   --long_name <argument>  ( -short <argument> )
580     //   help text
581 
582     // This variable is used to keep track of which options' info we've printed out, because some options can be in
583     // more than one usage level, but we only want to print the long form of its information once.
584 
585     OptionSet options_seen;
586     OptionSet::iterator pos;
587     strm.IndentMore (5);
588 
589     std::vector<char> sorted_options;
590 
591 
592     // Put the unique command options in a vector & sort it, so we can output them alphabetically (by short_option)
593     // when writing out detailed help for each option.
594 
595     for (i = 0; i < num_options; ++i)
596     {
597         pos = options_seen.find (opt_defs[i].short_option);
598         if (pos == options_seen.end())
599         {
600             options_seen.insert (opt_defs[i].short_option);
601             sorted_options.push_back (opt_defs[i].short_option);
602         }
603     }
604 
605     std::sort (sorted_options.begin(), sorted_options.end());
606 
607     // Go through the unique'd and alphabetically sorted vector of options, find the table entry for each option
608     // and write out the detailed help information for that option.
609 
610     int first_option_printed = 1;
611     size_t end = sorted_options.size();
612     for (size_t j = 0; j < end; ++j)
613     {
614         char option = sorted_options[j];
615         bool found = false;
616         for (i = 0; i < num_options && !found; ++i)
617         {
618             if (opt_defs[i].short_option == option)
619             {
620                 found = true;
621                 //Print out the help information for this option.
622 
623                 // Put a newline separation between arguments
624                 if (first_option_printed)
625                     first_option_printed = 0;
626                 else
627                     strm.EOL();
628 
629                 CommandArgumentType arg_type = opt_defs[i].argument_type;
630 
631                 StreamString arg_name_str;
632                 arg_name_str.Printf ("<%s>", CommandObject::GetArgumentName (arg_type));
633 
634                 strm.Indent ();
635                 strm.Printf ("-%c", opt_defs[i].short_option);
636                 if (arg_type != eArgTypeNone)
637                     strm.Printf (" <%s>",  CommandObject::GetArgumentName (arg_type));
638                 strm.Printf ("  ( --%s", opt_defs[i].long_option);
639                 if (arg_type != eArgTypeNone)
640                     strm.Printf (" <%s>", CommandObject::GetArgumentName (arg_type));
641                 strm.PutCString(" )\n");
642 
643                 strm.IndentMore (5);
644 
645                 if (opt_defs[i].usage_text)
646                     OutputFormattedUsageText (strm,
647                                               opt_defs[i].usage_text,
648                                               screen_width);
649                 if (opt_defs[i].enum_values != NULL)
650                 {
651                     strm.Indent ();
652                     strm.Printf("Values: ");
653                     for (int k = 0; opt_defs[i].enum_values[k].string_value != NULL; k++)
654                     {
655                         if (k == 0)
656                             strm.Printf("%s", opt_defs[i].enum_values[k].string_value);
657                         else
658                             strm.Printf(" | %s", opt_defs[i].enum_values[k].string_value);
659                     }
660                     strm.EOL();
661                 }
662                 strm.IndentLess (5);
663             }
664         }
665     }
666 
667     // Restore the indent level
668     strm.SetIndentLevel (save_indent_level);
669 }
670 
671 // This function is called when we have been given a potentially incomplete set of
672 // options, such as when an alias has been defined (more options might be added at
673 // at the time the alias is invoked).  We need to verify that the options in the set
674 // m_seen_options are all part of a set that may be used together, but m_seen_options
675 // may be missing some of the "required" options.
676 
677 bool
678 Options::VerifyPartialOptions (CommandReturnObject &result)
679 {
680     bool options_are_valid = false;
681 
682     int num_levels = GetRequiredOptions().size();
683     if (num_levels)
684       {
685         for (int i = 0; i < num_levels && !options_are_valid; ++i)
686           {
687             // In this case we are treating all options as optional rather than required.
688             // Therefore a set of options is correct if m_seen_options is a subset of the
689             // union of m_required_options and m_optional_options.
690             OptionSet union_set;
691             OptionsSetUnion (GetRequiredOptions()[i], GetOptionalOptions()[i], union_set);
692             if (IsASubset (m_seen_options, union_set))
693                 options_are_valid = true;
694           }
695       }
696 
697     return options_are_valid;
698 }
699 
700 bool
701 Options::HandleOptionCompletion
702 (
703     Args &input,
704     OptionElementVector &opt_element_vector,
705     int cursor_index,
706     int char_pos,
707     int match_start_point,
708     int max_return_elements,
709     bool &word_complete,
710     lldb_private::StringList &matches
711 )
712 {
713     word_complete = true;
714 
715     // For now we just scan the completions to see if the cursor position is in
716     // an option or its argument.  Otherwise we'll call HandleArgumentCompletion.
717     // In the future we can use completion to validate options as well if we want.
718 
719     const OptionDefinition *opt_defs = GetDefinitions();
720 
721     std::string cur_opt_std_str (input.GetArgumentAtIndex(cursor_index));
722     cur_opt_std_str.erase(char_pos);
723     const char *cur_opt_str = cur_opt_std_str.c_str();
724 
725     for (int i = 0; i < opt_element_vector.size(); i++)
726     {
727         int opt_pos = opt_element_vector[i].opt_pos;
728         int opt_arg_pos = opt_element_vector[i].opt_arg_pos;
729         int opt_defs_index = opt_element_vector[i].opt_defs_index;
730         if (opt_pos == cursor_index)
731         {
732             // We're completing the option itself.
733 
734             if (opt_defs_index == OptionArgElement::eBareDash)
735             {
736                 // We're completing a bare dash.  That means all options are open.
737                 // FIXME: We should scan the other options provided and only complete options
738                 // within the option group they belong to.
739                 char opt_str[3] = {'-', 'a', '\0'};
740 
741                 for (int j = 0 ; opt_defs[j].short_option != 0 ; j++)
742                 {
743                     opt_str[1] = opt_defs[j].short_option;
744                     matches.AppendString (opt_str);
745                 }
746                 return true;
747             }
748             else if (opt_defs_index == OptionArgElement::eBareDoubleDash)
749             {
750                 std::string full_name ("--");
751                 for (int j = 0 ; opt_defs[j].short_option != 0 ; j++)
752                 {
753                     full_name.erase(full_name.begin() + 2, full_name.end());
754                     full_name.append (opt_defs[j].long_option);
755                     matches.AppendString (full_name.c_str());
756                 }
757                 return true;
758             }
759             else if (opt_defs_index != OptionArgElement::eUnrecognizedArg)
760             {
761                 // We recognized it, if it an incomplete long option, complete it anyway (getopt_long is
762                 // happy with shortest unique string, but it's still a nice thing to do.)  Otherwise return
763                 // The string so the upper level code will know this is a full match and add the " ".
764                 if (cur_opt_str && strlen (cur_opt_str) > 2
765                     && cur_opt_str[0] == '-' && cur_opt_str[1] == '-'
766                     && strcmp (opt_defs[opt_defs_index].long_option, cur_opt_str) != 0)
767                 {
768                         std::string full_name ("--");
769                         full_name.append (opt_defs[opt_defs_index].long_option);
770                         matches.AppendString(full_name.c_str());
771                         return true;
772                 }
773                 else
774                 {
775                     matches.AppendString(input.GetArgumentAtIndex(cursor_index));
776                     return true;
777                 }
778             }
779             else
780             {
781                 // FIXME - not handling wrong options yet:
782                 // Check to see if they are writing a long option & complete it.
783                 // I think we will only get in here if the long option table has two elements
784                 // that are not unique up to this point.  getopt_long does shortest unique match
785                 // for long options already.
786 
787                 if (cur_opt_str && strlen (cur_opt_str) > 2
788                     && cur_opt_str[0] == '-' && cur_opt_str[1] == '-')
789                 {
790                     for (int j = 0 ; opt_defs[j].short_option != 0 ; j++)
791                     {
792                         if (strstr(opt_defs[j].long_option, cur_opt_str + 2) == opt_defs[j].long_option)
793                         {
794                             std::string full_name ("--");
795                             full_name.append (opt_defs[j].long_option);
796                             // The options definitions table has duplicates because of the
797                             // way the grouping information is stored, so only add once.
798                             bool duplicate = false;
799                             for (int k = 0; k < matches.GetSize(); k++)
800                             {
801                                 if (matches.GetStringAtIndex(k) == full_name)
802                                 {
803                                     duplicate = true;
804                                     break;
805                                 }
806                             }
807                             if (!duplicate)
808                                 matches.AppendString(full_name.c_str());
809                         }
810                     }
811                 }
812                 return true;
813             }
814 
815 
816         }
817         else if (opt_arg_pos == cursor_index)
818         {
819             // Okay the cursor is on the completion of an argument.
820             // See if it has a completion, otherwise return no matches.
821 
822             if (opt_defs_index != -1)
823             {
824                 HandleOptionArgumentCompletion (input,
825                                                 cursor_index,
826                                                 strlen (input.GetArgumentAtIndex(cursor_index)),
827                                                 opt_element_vector,
828                                                 i,
829                                                 match_start_point,
830                                                 max_return_elements,
831                                                 word_complete,
832                                                 matches);
833                 return true;
834             }
835             else
836             {
837                 // No completion callback means no completions...
838                 return true;
839             }
840 
841         }
842         else
843         {
844             // Not the last element, keep going.
845             continue;
846         }
847     }
848     return false;
849 }
850 
851 bool
852 Options::HandleOptionArgumentCompletion
853 (
854     Args &input,
855     int cursor_index,
856     int char_pos,
857     OptionElementVector &opt_element_vector,
858     int opt_element_index,
859     int match_start_point,
860     int max_return_elements,
861     bool &word_complete,
862     lldb_private::StringList &matches
863 )
864 {
865     const OptionDefinition *opt_defs = GetDefinitions();
866     std::auto_ptr<SearchFilter> filter_ap;
867 
868     int opt_arg_pos = opt_element_vector[opt_element_index].opt_arg_pos;
869     int opt_defs_index = opt_element_vector[opt_element_index].opt_defs_index;
870 
871     // See if this is an enumeration type option, and if so complete it here:
872 
873     OptionEnumValueElement *enum_values = opt_defs[opt_defs_index].enum_values;
874     if (enum_values != NULL)
875     {
876         bool return_value = false;
877         std::string match_string(input.GetArgumentAtIndex (opt_arg_pos), input.GetArgumentAtIndex (opt_arg_pos) + char_pos);
878         for (int i = 0; enum_values[i].string_value != NULL; i++)
879         {
880             if (strstr(enum_values[i].string_value, match_string.c_str()) == enum_values[i].string_value)
881             {
882                 matches.AppendString (enum_values[i].string_value);
883                 return_value = true;
884             }
885         }
886         return return_value;
887     }
888 
889     // If this is a source file or symbol type completion, and  there is a
890     // -shlib option somewhere in the supplied arguments, then make a search filter
891     // for that shared library.
892     // FIXME: Do we want to also have an "OptionType" so we don't have to match string names?
893 
894     uint32_t completion_mask = opt_defs[opt_defs_index].completion_type;
895 
896     if (completion_mask == 0)
897     {
898         lldb::CommandArgumentType option_arg_type = opt_defs[opt_defs_index].argument_type;
899         if (option_arg_type != eArgTypeNone)
900         {
901             CommandObject::ArgumentTableEntry *arg_entry = CommandObject::FindArgumentDataByType (opt_defs[opt_defs_index].argument_type);
902             if (arg_entry)
903                 completion_mask = arg_entry->completion_type;
904         }
905     }
906 
907     if (completion_mask & CommandCompletions::eSourceFileCompletion
908         || completion_mask & CommandCompletions::eSymbolCompletion)
909     {
910         for (int i = 0; i < opt_element_vector.size(); i++)
911         {
912             int cur_defs_index = opt_element_vector[i].opt_defs_index;
913             int cur_arg_pos    = opt_element_vector[i].opt_arg_pos;
914             const char *cur_opt_name = opt_defs[cur_defs_index].long_option;
915 
916             // If this is the "shlib" option and there was an argument provided,
917             // restrict it to that shared library.
918             if (strcmp(cur_opt_name, "shlib") == 0 && cur_arg_pos != -1)
919             {
920                 const char *module_name = input.GetArgumentAtIndex(cur_arg_pos);
921                 if (module_name)
922                 {
923                     FileSpec module_spec(module_name, false);
924                     lldb::TargetSP target_sp = m_interpreter.GetDebugger().GetSelectedTarget();
925                     // Search filters require a target...
926                     if (target_sp)
927                         filter_ap.reset (new SearchFilterByModule (target_sp, module_spec));
928                 }
929                 break;
930             }
931         }
932     }
933 
934     return CommandCompletions::InvokeCommonCompletionCallbacks (m_interpreter,
935                                                                 completion_mask,
936                                                                 input.GetArgumentAtIndex (opt_arg_pos),
937                                                                 match_start_point,
938                                                                 max_return_elements,
939                                                                 filter_ap.get(),
940                                                                 word_complete,
941                                                                 matches);
942 
943 }
944 
945 
946 void
947 OptionGroupOptions::Append (OptionGroup* group)
948 {
949     const OptionDefinition* group_option_defs = group->GetDefinitions ();
950     const uint32_t group_option_count = group->GetNumDefinitions();
951     for (uint32_t i=0; i<group_option_count; ++i)
952     {
953         m_option_infos.push_back (OptionInfo (group, i));
954         m_option_defs.push_back (group_option_defs[i]);
955     }
956 }
957 
958 void
959 OptionGroupOptions::Append (OptionGroup* group,
960                             uint32_t src_mask,
961                             uint32_t dst_mask)
962 {
963     const OptionDefinition* group_option_defs = group->GetDefinitions ();
964     const uint32_t group_option_count = group->GetNumDefinitions();
965     for (uint32_t i=0; i<group_option_count; ++i)
966     {
967         if (group_option_defs[i].usage_mask & src_mask)
968         {
969             m_option_infos.push_back (OptionInfo (group, i));
970             m_option_defs.push_back (group_option_defs[i]);
971             m_option_defs.back().usage_mask = dst_mask;
972         }
973     }
974 }
975 
976 void
977 OptionGroupOptions::Finalize ()
978 {
979     m_did_finalize = true;
980     OptionDefinition empty_option_def = { 0, false, NULL, 0, 0, NULL, 0, eArgTypeNone, NULL };
981     m_option_defs.push_back (empty_option_def);
982 }
983 
984 Error
985 OptionGroupOptions::SetOptionValue (uint32_t option_idx,
986                                     const char *option_value)
987 {
988     // After calling OptionGroupOptions::Append(...), you must finalize the groups
989     // by calling OptionGroupOptions::Finlize()
990     assert (m_did_finalize);
991     assert (m_option_infos.size() + 1 == m_option_defs.size());
992     Error error;
993     if (option_idx < m_option_infos.size())
994     {
995         error = m_option_infos[option_idx].option_group->SetOptionValue (m_interpreter,
996                                                                          m_option_infos[option_idx].option_index,
997                                                                          option_value);
998 
999     }
1000     else
1001     {
1002         error.SetErrorString ("invalid option index"); // Shouldn't happen...
1003     }
1004     return error;
1005 }
1006 
1007 void
1008 OptionGroupOptions::OptionParsingStarting ()
1009 {
1010     std::set<OptionGroup*> group_set;
1011     OptionInfos::iterator pos, end = m_option_infos.end();
1012     for (pos = m_option_infos.begin(); pos != end; ++pos)
1013     {
1014         OptionGroup* group = pos->option_group;
1015         if (group_set.find(group) == group_set.end())
1016         {
1017             group->OptionParsingStarting (m_interpreter);
1018             group_set.insert(group);
1019         }
1020     }
1021 }
1022 Error
1023 OptionGroupOptions::OptionParsingFinished ()
1024 {
1025     std::set<OptionGroup*> group_set;
1026     Error error;
1027     OptionInfos::iterator pos, end = m_option_infos.end();
1028     for (pos = m_option_infos.begin(); pos != end; ++pos)
1029     {
1030         OptionGroup* group = pos->option_group;
1031         if (group_set.find(group) == group_set.end())
1032         {
1033             error = group->OptionParsingFinished (m_interpreter);
1034             group_set.insert(group);
1035             if (error.Fail())
1036                 return error;
1037         }
1038     }
1039     return error;
1040 }
1041