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      1 //===-- CommandLine.cpp - Command line parser implementation --------------===//
      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 // This class implements a command line argument processor that is useful when
     11 // creating a tool.  It provides a simple, minimalistic interface that is easily
     12 // extensible and supports nonlocal (library) command line options.
     13 //
     14 // Note that rather than trying to figure out what this code does, you could try
     15 // reading the library documentation located in docs/CommandLine.html
     16 //
     17 //===----------------------------------------------------------------------===//
     18 
     19 #include "llvm/Support/CommandLine.h"
     20 #include "llvm-c/Support.h"
     21 #include "llvm/ADT/ArrayRef.h"
     22 #include "llvm/ADT/DenseMap.h"
     23 #include "llvm/ADT/STLExtras.h"
     24 #include "llvm/ADT/SmallPtrSet.h"
     25 #include "llvm/ADT/SmallString.h"
     26 #include "llvm/ADT/StringMap.h"
     27 #include "llvm/ADT/Twine.h"
     28 #include "llvm/Config/config.h"
     29 #include "llvm/Support/ConvertUTF.h"
     30 #include "llvm/Support/Debug.h"
     31 #include "llvm/Support/ErrorHandling.h"
     32 #include "llvm/Support/Host.h"
     33 #include "llvm/Support/ManagedStatic.h"
     34 #include "llvm/Support/MemoryBuffer.h"
     35 #include "llvm/Support/Path.h"
     36 #include "llvm/Support/StringSaver.h"
     37 #include "llvm/Support/raw_ostream.h"
     38 #include <cstdlib>
     39 #include <map>
     40 using namespace llvm;
     41 using namespace cl;
     42 
     43 #define DEBUG_TYPE "commandline"
     44 
     45 //===----------------------------------------------------------------------===//
     46 // Template instantiations and anchors.
     47 //
     48 namespace llvm {
     49 namespace cl {
     50 template class basic_parser<bool>;
     51 template class basic_parser<boolOrDefault>;
     52 template class basic_parser<int>;
     53 template class basic_parser<unsigned>;
     54 template class basic_parser<unsigned long long>;
     55 template class basic_parser<double>;
     56 template class basic_parser<float>;
     57 template class basic_parser<std::string>;
     58 template class basic_parser<char>;
     59 
     60 template class opt<unsigned>;
     61 template class opt<int>;
     62 template class opt<std::string>;
     63 template class opt<char>;
     64 template class opt<bool>;
     65 }
     66 } // end namespace llvm::cl
     67 
     68 // Pin the vtables to this file.
     69 void GenericOptionValue::anchor() {}
     70 void OptionValue<boolOrDefault>::anchor() {}
     71 void OptionValue<std::string>::anchor() {}
     72 void Option::anchor() {}
     73 void basic_parser_impl::anchor() {}
     74 void parser<bool>::anchor() {}
     75 void parser<boolOrDefault>::anchor() {}
     76 void parser<int>::anchor() {}
     77 void parser<unsigned>::anchor() {}
     78 void parser<unsigned long long>::anchor() {}
     79 void parser<double>::anchor() {}
     80 void parser<float>::anchor() {}
     81 void parser<std::string>::anchor() {}
     82 void parser<char>::anchor() {}
     83 
     84 //===----------------------------------------------------------------------===//
     85 
     86 namespace {
     87 
     88 class CommandLineParser {
     89 public:
     90   // Globals for name and overview of program.  Program name is not a string to
     91   // avoid static ctor/dtor issues.
     92   std::string ProgramName;
     93   const char *ProgramOverview;
     94 
     95   // This collects additional help to be printed.
     96   std::vector<const char *> MoreHelp;
     97 
     98   // This collects the different option categories that have been registered.
     99   SmallPtrSet<OptionCategory *, 16> RegisteredOptionCategories;
    100 
    101   // This collects the different subcommands that have been registered.
    102   SmallPtrSet<SubCommand *, 4> RegisteredSubCommands;
    103 
    104   CommandLineParser() : ProgramOverview(nullptr), ActiveSubCommand(nullptr) {
    105     registerSubCommand(&*TopLevelSubCommand);
    106     registerSubCommand(&*AllSubCommands);
    107   }
    108 
    109   void ResetAllOptionOccurrences();
    110 
    111   bool ParseCommandLineOptions(int argc, const char *const *argv,
    112                                const char *Overview, bool IgnoreErrors);
    113 
    114   void addLiteralOption(Option &Opt, SubCommand *SC, const char *Name) {
    115     if (Opt.hasArgStr())
    116       return;
    117     if (!SC->OptionsMap.insert(std::make_pair(Name, &Opt)).second) {
    118       errs() << ProgramName << ": CommandLine Error: Option '" << Name
    119              << "' registered more than once!\n";
    120       report_fatal_error("inconsistency in registered CommandLine options");
    121     }
    122 
    123     // If we're adding this to all sub-commands, add it to the ones that have
    124     // already been registered.
    125     if (SC == &*AllSubCommands) {
    126       for (const auto &Sub : RegisteredSubCommands) {
    127         if (SC == Sub)
    128           continue;
    129         addLiteralOption(Opt, Sub, Name);
    130       }
    131     }
    132   }
    133 
    134   void addLiteralOption(Option &Opt, const char *Name) {
    135     if (Opt.Subs.empty())
    136       addLiteralOption(Opt, &*TopLevelSubCommand, Name);
    137     else {
    138       for (auto SC : Opt.Subs)
    139         addLiteralOption(Opt, SC, Name);
    140     }
    141   }
    142 
    143   void addOption(Option *O, SubCommand *SC) {
    144     bool HadErrors = false;
    145     if (O->hasArgStr()) {
    146       // Add argument to the argument map!
    147       if (!SC->OptionsMap.insert(std::make_pair(O->ArgStr, O)).second) {
    148         errs() << ProgramName << ": CommandLine Error: Option '" << O->ArgStr
    149                << "' registered more than once!\n";
    150         HadErrors = true;
    151       }
    152     }
    153 
    154     // Remember information about positional options.
    155     if (O->getFormattingFlag() == cl::Positional)
    156       SC->PositionalOpts.push_back(O);
    157     else if (O->getMiscFlags() & cl::Sink) // Remember sink options
    158       SC->SinkOpts.push_back(O);
    159     else if (O->getNumOccurrencesFlag() == cl::ConsumeAfter) {
    160       if (SC->ConsumeAfterOpt) {
    161         O->error("Cannot specify more than one option with cl::ConsumeAfter!");
    162         HadErrors = true;
    163       }
    164       SC->ConsumeAfterOpt = O;
    165     }
    166 
    167     // Fail hard if there were errors. These are strictly unrecoverable and
    168     // indicate serious issues such as conflicting option names or an
    169     // incorrectly
    170     // linked LLVM distribution.
    171     if (HadErrors)
    172       report_fatal_error("inconsistency in registered CommandLine options");
    173 
    174     // If we're adding this to all sub-commands, add it to the ones that have
    175     // already been registered.
    176     if (SC == &*AllSubCommands) {
    177       for (const auto &Sub : RegisteredSubCommands) {
    178         if (SC == Sub)
    179           continue;
    180         addOption(O, Sub);
    181       }
    182     }
    183   }
    184 
    185   void addOption(Option *O) {
    186     if (O->Subs.empty()) {
    187       addOption(O, &*TopLevelSubCommand);
    188     } else {
    189       for (auto SC : O->Subs)
    190         addOption(O, SC);
    191     }
    192   }
    193 
    194   void removeOption(Option *O, SubCommand *SC) {
    195     SmallVector<StringRef, 16> OptionNames;
    196     O->getExtraOptionNames(OptionNames);
    197     if (O->hasArgStr())
    198       OptionNames.push_back(O->ArgStr);
    199 
    200     SubCommand &Sub = *SC;
    201     for (auto Name : OptionNames)
    202       Sub.OptionsMap.erase(Name);
    203 
    204     if (O->getFormattingFlag() == cl::Positional)
    205       for (auto Opt = Sub.PositionalOpts.begin();
    206            Opt != Sub.PositionalOpts.end(); ++Opt) {
    207         if (*Opt == O) {
    208           Sub.PositionalOpts.erase(Opt);
    209           break;
    210         }
    211       }
    212     else if (O->getMiscFlags() & cl::Sink)
    213       for (auto Opt = Sub.SinkOpts.begin(); Opt != Sub.SinkOpts.end(); ++Opt) {
    214         if (*Opt == O) {
    215           Sub.SinkOpts.erase(Opt);
    216           break;
    217         }
    218       }
    219     else if (O == Sub.ConsumeAfterOpt)
    220       Sub.ConsumeAfterOpt = nullptr;
    221   }
    222 
    223   void removeOption(Option *O) {
    224     if (O->Subs.empty())
    225       removeOption(O, &*TopLevelSubCommand);
    226     else {
    227       if (O->isInAllSubCommands()) {
    228         for (auto SC : RegisteredSubCommands)
    229           removeOption(O, SC);
    230       } else {
    231         for (auto SC : O->Subs)
    232           removeOption(O, SC);
    233       }
    234     }
    235   }
    236 
    237   bool hasOptions(const SubCommand &Sub) const {
    238     return (!Sub.OptionsMap.empty() || !Sub.PositionalOpts.empty() ||
    239             nullptr != Sub.ConsumeAfterOpt);
    240   }
    241 
    242   bool hasOptions() const {
    243     for (const auto &S : RegisteredSubCommands) {
    244       if (hasOptions(*S))
    245         return true;
    246     }
    247     return false;
    248   }
    249 
    250   SubCommand *getActiveSubCommand() { return ActiveSubCommand; }
    251 
    252   void updateArgStr(Option *O, StringRef NewName, SubCommand *SC) {
    253     SubCommand &Sub = *SC;
    254     if (!Sub.OptionsMap.insert(std::make_pair(NewName, O)).second) {
    255       errs() << ProgramName << ": CommandLine Error: Option '" << O->ArgStr
    256              << "' registered more than once!\n";
    257       report_fatal_error("inconsistency in registered CommandLine options");
    258     }
    259     Sub.OptionsMap.erase(O->ArgStr);
    260   }
    261 
    262   void updateArgStr(Option *O, StringRef NewName) {
    263     if (O->Subs.empty())
    264       updateArgStr(O, NewName, &*TopLevelSubCommand);
    265     else {
    266       for (auto SC : O->Subs)
    267         updateArgStr(O, NewName, SC);
    268     }
    269   }
    270 
    271   void printOptionValues();
    272 
    273   void registerCategory(OptionCategory *cat) {
    274     assert(count_if(RegisteredOptionCategories,
    275                     [cat](const OptionCategory *Category) {
    276              return cat->getName() == Category->getName();
    277            }) == 0 &&
    278            "Duplicate option categories");
    279 
    280     RegisteredOptionCategories.insert(cat);
    281   }
    282 
    283   void registerSubCommand(SubCommand *sub) {
    284     assert(count_if(RegisteredSubCommands,
    285                     [sub](const SubCommand *Sub) {
    286                       return (sub->getName() != nullptr) &&
    287                              (Sub->getName() == sub->getName());
    288                     }) == 0 &&
    289            "Duplicate subcommands");
    290     RegisteredSubCommands.insert(sub);
    291 
    292     // For all options that have been registered for all subcommands, add the
    293     // option to this subcommand now.
    294     if (sub != &*AllSubCommands) {
    295       for (auto &E : AllSubCommands->OptionsMap) {
    296         Option *O = E.second;
    297         if ((O->isPositional() || O->isSink() || O->isConsumeAfter()) ||
    298             O->hasArgStr())
    299           addOption(O, sub);
    300         else
    301           addLiteralOption(*O, sub, E.first().str().c_str());
    302       }
    303     }
    304   }
    305 
    306   void unregisterSubCommand(SubCommand *sub) {
    307     RegisteredSubCommands.erase(sub);
    308   }
    309 
    310   void reset() {
    311     ActiveSubCommand = nullptr;
    312     ProgramName.clear();
    313     ProgramOverview = nullptr;
    314 
    315     MoreHelp.clear();
    316     RegisteredOptionCategories.clear();
    317 
    318     ResetAllOptionOccurrences();
    319     RegisteredSubCommands.clear();
    320 
    321     TopLevelSubCommand->reset();
    322     AllSubCommands->reset();
    323     registerSubCommand(&*TopLevelSubCommand);
    324     registerSubCommand(&*AllSubCommands);
    325   }
    326 
    327 private:
    328   SubCommand *ActiveSubCommand;
    329 
    330   Option *LookupOption(SubCommand &Sub, StringRef &Arg, StringRef &Value);
    331   SubCommand *LookupSubCommand(const char *Name);
    332 };
    333 
    334 } // namespace
    335 
    336 static ManagedStatic<CommandLineParser> GlobalParser;
    337 
    338 void cl::AddLiteralOption(Option &O, const char *Name) {
    339   GlobalParser->addLiteralOption(O, Name);
    340 }
    341 
    342 extrahelp::extrahelp(const char *Help) : morehelp(Help) {
    343   GlobalParser->MoreHelp.push_back(Help);
    344 }
    345 
    346 void Option::addArgument() {
    347   GlobalParser->addOption(this);
    348   FullyInitialized = true;
    349 }
    350 
    351 void Option::removeArgument() { GlobalParser->removeOption(this); }
    352 
    353 void Option::setArgStr(StringRef S) {
    354   if (FullyInitialized)
    355     GlobalParser->updateArgStr(this, S);
    356   ArgStr = S;
    357 }
    358 
    359 // Initialise the general option category.
    360 OptionCategory llvm::cl::GeneralCategory("General options");
    361 
    362 void OptionCategory::registerCategory() {
    363   GlobalParser->registerCategory(this);
    364 }
    365 
    366 // A special subcommand representing no subcommand
    367 ManagedStatic<SubCommand> llvm::cl::TopLevelSubCommand;
    368 
    369 // A special subcommand that can be used to put an option into all subcommands.
    370 ManagedStatic<SubCommand> llvm::cl::AllSubCommands;
    371 
    372 void SubCommand::registerSubCommand() {
    373   GlobalParser->registerSubCommand(this);
    374 }
    375 
    376 void SubCommand::unregisterSubCommand() {
    377   GlobalParser->unregisterSubCommand(this);
    378 }
    379 
    380 void SubCommand::reset() {
    381   PositionalOpts.clear();
    382   SinkOpts.clear();
    383   OptionsMap.clear();
    384 
    385   ConsumeAfterOpt = nullptr;
    386 }
    387 
    388 SubCommand::operator bool() const {
    389   return (GlobalParser->getActiveSubCommand() == this);
    390 }
    391 
    392 //===----------------------------------------------------------------------===//
    393 // Basic, shared command line option processing machinery.
    394 //
    395 
    396 /// LookupOption - Lookup the option specified by the specified option on the
    397 /// command line.  If there is a value specified (after an equal sign) return
    398 /// that as well.  This assumes that leading dashes have already been stripped.
    399 Option *CommandLineParser::LookupOption(SubCommand &Sub, StringRef &Arg,
    400                                         StringRef &Value) {
    401   // Reject all dashes.
    402   if (Arg.empty())
    403     return nullptr;
    404   assert(&Sub != &*AllSubCommands);
    405 
    406   size_t EqualPos = Arg.find('=');
    407 
    408   // If we have an equals sign, remember the value.
    409   if (EqualPos == StringRef::npos) {
    410     // Look up the option.
    411     auto I = Sub.OptionsMap.find(Arg);
    412     if (I == Sub.OptionsMap.end())
    413       return nullptr;
    414 
    415     return I != Sub.OptionsMap.end() ? I->second : nullptr;
    416   }
    417 
    418   // If the argument before the = is a valid option name, we match.  If not,
    419   // return Arg unmolested.
    420   auto I = Sub.OptionsMap.find(Arg.substr(0, EqualPos));
    421   if (I == Sub.OptionsMap.end())
    422     return nullptr;
    423 
    424   Value = Arg.substr(EqualPos + 1);
    425   Arg = Arg.substr(0, EqualPos);
    426   return I->second;
    427 }
    428 
    429 SubCommand *CommandLineParser::LookupSubCommand(const char *Name) {
    430   if (Name == nullptr)
    431     return &*TopLevelSubCommand;
    432   for (auto S : RegisteredSubCommands) {
    433     if (S == &*AllSubCommands)
    434       continue;
    435     if (S->getName() == nullptr)
    436       continue;
    437 
    438     if (StringRef(S->getName()) == StringRef(Name))
    439       return S;
    440   }
    441   return &*TopLevelSubCommand;
    442 }
    443 
    444 /// LookupNearestOption - Lookup the closest match to the option specified by
    445 /// the specified option on the command line.  If there is a value specified
    446 /// (after an equal sign) return that as well.  This assumes that leading dashes
    447 /// have already been stripped.
    448 static Option *LookupNearestOption(StringRef Arg,
    449                                    const StringMap<Option *> &OptionsMap,
    450                                    std::string &NearestString) {
    451   // Reject all dashes.
    452   if (Arg.empty())
    453     return nullptr;
    454 
    455   // Split on any equal sign.
    456   std::pair<StringRef, StringRef> SplitArg = Arg.split('=');
    457   StringRef &LHS = SplitArg.first; // LHS == Arg when no '=' is present.
    458   StringRef &RHS = SplitArg.second;
    459 
    460   // Find the closest match.
    461   Option *Best = nullptr;
    462   unsigned BestDistance = 0;
    463   for (StringMap<Option *>::const_iterator it = OptionsMap.begin(),
    464                                            ie = OptionsMap.end();
    465        it != ie; ++it) {
    466     Option *O = it->second;
    467     SmallVector<StringRef, 16> OptionNames;
    468     O->getExtraOptionNames(OptionNames);
    469     if (O->hasArgStr())
    470       OptionNames.push_back(O->ArgStr);
    471 
    472     bool PermitValue = O->getValueExpectedFlag() != cl::ValueDisallowed;
    473     StringRef Flag = PermitValue ? LHS : Arg;
    474     for (auto Name : OptionNames) {
    475       unsigned Distance = StringRef(Name).edit_distance(
    476           Flag, /*AllowReplacements=*/true, /*MaxEditDistance=*/BestDistance);
    477       if (!Best || Distance < BestDistance) {
    478         Best = O;
    479         BestDistance = Distance;
    480         if (RHS.empty() || !PermitValue)
    481           NearestString = Name;
    482         else
    483           NearestString = (Twine(Name) + "=" + RHS).str();
    484       }
    485     }
    486   }
    487 
    488   return Best;
    489 }
    490 
    491 /// CommaSeparateAndAddOccurrence - A wrapper around Handler->addOccurrence()
    492 /// that does special handling of cl::CommaSeparated options.
    493 static bool CommaSeparateAndAddOccurrence(Option *Handler, unsigned pos,
    494                                           StringRef ArgName, StringRef Value,
    495                                           bool MultiArg = false) {
    496   // Check to see if this option accepts a comma separated list of values.  If
    497   // it does, we have to split up the value into multiple values.
    498   if (Handler->getMiscFlags() & CommaSeparated) {
    499     StringRef Val(Value);
    500     StringRef::size_type Pos = Val.find(',');
    501 
    502     while (Pos != StringRef::npos) {
    503       // Process the portion before the comma.
    504       if (Handler->addOccurrence(pos, ArgName, Val.substr(0, Pos), MultiArg))
    505         return true;
    506       // Erase the portion before the comma, AND the comma.
    507       Val = Val.substr(Pos + 1);
    508       Value.substr(Pos + 1); // Increment the original value pointer as well.
    509       // Check for another comma.
    510       Pos = Val.find(',');
    511     }
    512 
    513     Value = Val;
    514   }
    515 
    516   return Handler->addOccurrence(pos, ArgName, Value, MultiArg);
    517 }
    518 
    519 /// ProvideOption - For Value, this differentiates between an empty value ("")
    520 /// and a null value (StringRef()).  The later is accepted for arguments that
    521 /// don't allow a value (-foo) the former is rejected (-foo=).
    522 static inline bool ProvideOption(Option *Handler, StringRef ArgName,
    523                                  StringRef Value, int argc,
    524                                  const char *const *argv, int &i) {
    525   // Is this a multi-argument option?
    526   unsigned NumAdditionalVals = Handler->getNumAdditionalVals();
    527 
    528   // Enforce value requirements
    529   switch (Handler->getValueExpectedFlag()) {
    530   case ValueRequired:
    531     if (!Value.data()) { // No value specified?
    532       if (i + 1 >= argc)
    533         return Handler->error("requires a value!");
    534       // Steal the next argument, like for '-o filename'
    535       assert(argv && "null check");
    536       Value = argv[++i];
    537     }
    538     break;
    539   case ValueDisallowed:
    540     if (NumAdditionalVals > 0)
    541       return Handler->error("multi-valued option specified"
    542                             " with ValueDisallowed modifier!");
    543 
    544     if (Value.data())
    545       return Handler->error("does not allow a value! '" + Twine(Value) +
    546                             "' specified.");
    547     break;
    548   case ValueOptional:
    549     break;
    550   }
    551 
    552   // If this isn't a multi-arg option, just run the handler.
    553   if (NumAdditionalVals == 0)
    554     return CommaSeparateAndAddOccurrence(Handler, i, ArgName, Value);
    555 
    556   // If it is, run the handle several times.
    557   bool MultiArg = false;
    558 
    559   if (Value.data()) {
    560     if (CommaSeparateAndAddOccurrence(Handler, i, ArgName, Value, MultiArg))
    561       return true;
    562     --NumAdditionalVals;
    563     MultiArg = true;
    564   }
    565 
    566   while (NumAdditionalVals > 0) {
    567     if (i + 1 >= argc)
    568       return Handler->error("not enough values!");
    569     assert(argv && "null check");
    570     Value = argv[++i];
    571 
    572     if (CommaSeparateAndAddOccurrence(Handler, i, ArgName, Value, MultiArg))
    573       return true;
    574     MultiArg = true;
    575     --NumAdditionalVals;
    576   }
    577   return false;
    578 }
    579 
    580 static bool ProvidePositionalOption(Option *Handler, StringRef Arg, int i) {
    581   int Dummy = i;
    582   return ProvideOption(Handler, Handler->ArgStr, Arg, 0, nullptr, Dummy);
    583 }
    584 
    585 // Option predicates...
    586 static inline bool isGrouping(const Option *O) {
    587   return O->getFormattingFlag() == cl::Grouping;
    588 }
    589 static inline bool isPrefixedOrGrouping(const Option *O) {
    590   return isGrouping(O) || O->getFormattingFlag() == cl::Prefix;
    591 }
    592 
    593 // getOptionPred - Check to see if there are any options that satisfy the
    594 // specified predicate with names that are the prefixes in Name.  This is
    595 // checked by progressively stripping characters off of the name, checking to
    596 // see if there options that satisfy the predicate.  If we find one, return it,
    597 // otherwise return null.
    598 //
    599 static Option *getOptionPred(StringRef Name, size_t &Length,
    600                              bool (*Pred)(const Option *),
    601                              const StringMap<Option *> &OptionsMap) {
    602 
    603   StringMap<Option *>::const_iterator OMI = OptionsMap.find(Name);
    604 
    605   // Loop while we haven't found an option and Name still has at least two
    606   // characters in it (so that the next iteration will not be the empty
    607   // string.
    608   while (OMI == OptionsMap.end() && Name.size() > 1) {
    609     Name = Name.substr(0, Name.size() - 1); // Chop off the last character.
    610     OMI = OptionsMap.find(Name);
    611   }
    612 
    613   if (OMI != OptionsMap.end() && Pred(OMI->second)) {
    614     Length = Name.size();
    615     return OMI->second; // Found one!
    616   }
    617   return nullptr; // No option found!
    618 }
    619 
    620 /// HandlePrefixedOrGroupedOption - The specified argument string (which started
    621 /// with at least one '-') does not fully match an available option.  Check to
    622 /// see if this is a prefix or grouped option.  If so, split arg into output an
    623 /// Arg/Value pair and return the Option to parse it with.
    624 static Option *
    625 HandlePrefixedOrGroupedOption(StringRef &Arg, StringRef &Value,
    626                               bool &ErrorParsing,
    627                               const StringMap<Option *> &OptionsMap) {
    628   if (Arg.size() == 1)
    629     return nullptr;
    630 
    631   // Do the lookup!
    632   size_t Length = 0;
    633   Option *PGOpt = getOptionPred(Arg, Length, isPrefixedOrGrouping, OptionsMap);
    634   if (!PGOpt)
    635     return nullptr;
    636 
    637   // If the option is a prefixed option, then the value is simply the
    638   // rest of the name...  so fall through to later processing, by
    639   // setting up the argument name flags and value fields.
    640   if (PGOpt->getFormattingFlag() == cl::Prefix) {
    641     Value = Arg.substr(Length);
    642     Arg = Arg.substr(0, Length);
    643     assert(OptionsMap.count(Arg) && OptionsMap.find(Arg)->second == PGOpt);
    644     return PGOpt;
    645   }
    646 
    647   // This must be a grouped option... handle them now.  Grouping options can't
    648   // have values.
    649   assert(isGrouping(PGOpt) && "Broken getOptionPred!");
    650 
    651   do {
    652     // Move current arg name out of Arg into OneArgName.
    653     StringRef OneArgName = Arg.substr(0, Length);
    654     Arg = Arg.substr(Length);
    655 
    656     // Because ValueRequired is an invalid flag for grouped arguments,
    657     // we don't need to pass argc/argv in.
    658     assert(PGOpt->getValueExpectedFlag() != cl::ValueRequired &&
    659            "Option can not be cl::Grouping AND cl::ValueRequired!");
    660     int Dummy = 0;
    661     ErrorParsing |=
    662         ProvideOption(PGOpt, OneArgName, StringRef(), 0, nullptr, Dummy);
    663 
    664     // Get the next grouping option.
    665     PGOpt = getOptionPred(Arg, Length, isGrouping, OptionsMap);
    666   } while (PGOpt && Length != Arg.size());
    667 
    668   // Return the last option with Arg cut down to just the last one.
    669   return PGOpt;
    670 }
    671 
    672 static bool RequiresValue(const Option *O) {
    673   return O->getNumOccurrencesFlag() == cl::Required ||
    674          O->getNumOccurrencesFlag() == cl::OneOrMore;
    675 }
    676 
    677 static bool EatsUnboundedNumberOfValues(const Option *O) {
    678   return O->getNumOccurrencesFlag() == cl::ZeroOrMore ||
    679          O->getNumOccurrencesFlag() == cl::OneOrMore;
    680 }
    681 
    682 static bool isWhitespace(char C) { return strchr(" \t\n\r\f\v", C); }
    683 
    684 static bool isQuote(char C) { return C == '\"' || C == '\''; }
    685 
    686 void cl::TokenizeGNUCommandLine(StringRef Src, StringSaver &Saver,
    687                                 SmallVectorImpl<const char *> &NewArgv,
    688                                 bool MarkEOLs) {
    689   SmallString<128> Token;
    690   for (size_t I = 0, E = Src.size(); I != E; ++I) {
    691     // Consume runs of whitespace.
    692     if (Token.empty()) {
    693       while (I != E && isWhitespace(Src[I])) {
    694         // Mark the end of lines in response files
    695         if (MarkEOLs && Src[I] == '\n')
    696           NewArgv.push_back(nullptr);
    697         ++I;
    698       }
    699       if (I == E)
    700         break;
    701     }
    702 
    703     // Backslash escapes the next character.
    704     if (I + 1 < E && Src[I] == '\\') {
    705       ++I; // Skip the escape.
    706       Token.push_back(Src[I]);
    707       continue;
    708     }
    709 
    710     // Consume a quoted string.
    711     if (isQuote(Src[I])) {
    712       char Quote = Src[I++];
    713       while (I != E && Src[I] != Quote) {
    714         // Backslash escapes the next character.
    715         if (Src[I] == '\\' && I + 1 != E)
    716           ++I;
    717         Token.push_back(Src[I]);
    718         ++I;
    719       }
    720       if (I == E)
    721         break;
    722       continue;
    723     }
    724 
    725     // End the token if this is whitespace.
    726     if (isWhitespace(Src[I])) {
    727       if (!Token.empty())
    728         NewArgv.push_back(Saver.save(Token.c_str()));
    729       Token.clear();
    730       continue;
    731     }
    732 
    733     // This is a normal character.  Append it.
    734     Token.push_back(Src[I]);
    735   }
    736 
    737   // Append the last token after hitting EOF with no whitespace.
    738   if (!Token.empty())
    739     NewArgv.push_back(Saver.save(Token.c_str()));
    740   // Mark the end of response files
    741   if (MarkEOLs)
    742     NewArgv.push_back(nullptr);
    743 }
    744 
    745 /// Backslashes are interpreted in a rather complicated way in the Windows-style
    746 /// command line, because backslashes are used both to separate path and to
    747 /// escape double quote. This method consumes runs of backslashes as well as the
    748 /// following double quote if it's escaped.
    749 ///
    750 ///  * If an even number of backslashes is followed by a double quote, one
    751 ///    backslash is output for every pair of backslashes, and the last double
    752 ///    quote remains unconsumed. The double quote will later be interpreted as
    753 ///    the start or end of a quoted string in the main loop outside of this
    754 ///    function.
    755 ///
    756 ///  * If an odd number of backslashes is followed by a double quote, one
    757 ///    backslash is output for every pair of backslashes, and a double quote is
    758 ///    output for the last pair of backslash-double quote. The double quote is
    759 ///    consumed in this case.
    760 ///
    761 ///  * Otherwise, backslashes are interpreted literally.
    762 static size_t parseBackslash(StringRef Src, size_t I, SmallString<128> &Token) {
    763   size_t E = Src.size();
    764   int BackslashCount = 0;
    765   // Skip the backslashes.
    766   do {
    767     ++I;
    768     ++BackslashCount;
    769   } while (I != E && Src[I] == '\\');
    770 
    771   bool FollowedByDoubleQuote = (I != E && Src[I] == '"');
    772   if (FollowedByDoubleQuote) {
    773     Token.append(BackslashCount / 2, '\\');
    774     if (BackslashCount % 2 == 0)
    775       return I - 1;
    776     Token.push_back('"');
    777     return I;
    778   }
    779   Token.append(BackslashCount, '\\');
    780   return I - 1;
    781 }
    782 
    783 void cl::TokenizeWindowsCommandLine(StringRef Src, StringSaver &Saver,
    784                                     SmallVectorImpl<const char *> &NewArgv,
    785                                     bool MarkEOLs) {
    786   SmallString<128> Token;
    787 
    788   // This is a small state machine to consume characters until it reaches the
    789   // end of the source string.
    790   enum { INIT, UNQUOTED, QUOTED } State = INIT;
    791   for (size_t I = 0, E = Src.size(); I != E; ++I) {
    792     // INIT state indicates that the current input index is at the start of
    793     // the string or between tokens.
    794     if (State == INIT) {
    795       if (isWhitespace(Src[I])) {
    796         // Mark the end of lines in response files
    797         if (MarkEOLs && Src[I] == '\n')
    798           NewArgv.push_back(nullptr);
    799         continue;
    800       }
    801       if (Src[I] == '"') {
    802         State = QUOTED;
    803         continue;
    804       }
    805       if (Src[I] == '\\') {
    806         I = parseBackslash(Src, I, Token);
    807         State = UNQUOTED;
    808         continue;
    809       }
    810       Token.push_back(Src[I]);
    811       State = UNQUOTED;
    812       continue;
    813     }
    814 
    815     // UNQUOTED state means that it's reading a token not quoted by double
    816     // quotes.
    817     if (State == UNQUOTED) {
    818       // Whitespace means the end of the token.
    819       if (isWhitespace(Src[I])) {
    820         NewArgv.push_back(Saver.save(Token.c_str()));
    821         Token.clear();
    822         State = INIT;
    823         // Mark the end of lines in response files
    824         if (MarkEOLs && Src[I] == '\n')
    825           NewArgv.push_back(nullptr);
    826         continue;
    827       }
    828       if (Src[I] == '"') {
    829         State = QUOTED;
    830         continue;
    831       }
    832       if (Src[I] == '\\') {
    833         I = parseBackslash(Src, I, Token);
    834         continue;
    835       }
    836       Token.push_back(Src[I]);
    837       continue;
    838     }
    839 
    840     // QUOTED state means that it's reading a token quoted by double quotes.
    841     if (State == QUOTED) {
    842       if (Src[I] == '"') {
    843         State = UNQUOTED;
    844         continue;
    845       }
    846       if (Src[I] == '\\') {
    847         I = parseBackslash(Src, I, Token);
    848         continue;
    849       }
    850       Token.push_back(Src[I]);
    851     }
    852   }
    853   // Append the last token after hitting EOF with no whitespace.
    854   if (!Token.empty())
    855     NewArgv.push_back(Saver.save(Token.c_str()));
    856   // Mark the end of response files
    857   if (MarkEOLs)
    858     NewArgv.push_back(nullptr);
    859 }
    860 
    861 // It is called byte order marker but the UTF-8 BOM is actually not affected
    862 // by the host system's endianness.
    863 static bool hasUTF8ByteOrderMark(ArrayRef<char> S) {
    864   return (S.size() >= 3 && S[0] == '\xef' && S[1] == '\xbb' && S[2] == '\xbf');
    865 }
    866 
    867 static bool ExpandResponseFile(const char *FName, StringSaver &Saver,
    868                                TokenizerCallback Tokenizer,
    869                                SmallVectorImpl<const char *> &NewArgv,
    870                                bool MarkEOLs = false) {
    871   ErrorOr<std::unique_ptr<MemoryBuffer>> MemBufOrErr =
    872       MemoryBuffer::getFile(FName);
    873   if (!MemBufOrErr)
    874     return false;
    875   MemoryBuffer &MemBuf = *MemBufOrErr.get();
    876   StringRef Str(MemBuf.getBufferStart(), MemBuf.getBufferSize());
    877 
    878   // If we have a UTF-16 byte order mark, convert to UTF-8 for parsing.
    879   ArrayRef<char> BufRef(MemBuf.getBufferStart(), MemBuf.getBufferEnd());
    880   std::string UTF8Buf;
    881   if (hasUTF16ByteOrderMark(BufRef)) {
    882     if (!convertUTF16ToUTF8String(BufRef, UTF8Buf))
    883       return false;
    884     Str = StringRef(UTF8Buf);
    885   }
    886   // If we see UTF-8 BOM sequence at the beginning of a file, we shall remove
    887   // these bytes before parsing.
    888   // Reference: http://en.wikipedia.org/wiki/UTF-8#Byte_order_mark
    889   else if (hasUTF8ByteOrderMark(BufRef))
    890     Str = StringRef(BufRef.data() + 3, BufRef.size() - 3);
    891 
    892   // Tokenize the contents into NewArgv.
    893   Tokenizer(Str, Saver, NewArgv, MarkEOLs);
    894 
    895   return true;
    896 }
    897 
    898 /// \brief Expand response files on a command line recursively using the given
    899 /// StringSaver and tokenization strategy.
    900 bool cl::ExpandResponseFiles(StringSaver &Saver, TokenizerCallback Tokenizer,
    901                              SmallVectorImpl<const char *> &Argv,
    902                              bool MarkEOLs) {
    903   unsigned RspFiles = 0;
    904   bool AllExpanded = true;
    905 
    906   // Don't cache Argv.size() because it can change.
    907   for (unsigned I = 0; I != Argv.size();) {
    908     const char *Arg = Argv[I];
    909     // Check if it is an EOL marker
    910     if (Arg == nullptr) {
    911       ++I;
    912       continue;
    913     }
    914     if (Arg[0] != '@') {
    915       ++I;
    916       continue;
    917     }
    918 
    919     // If we have too many response files, leave some unexpanded.  This avoids
    920     // crashing on self-referential response files.
    921     if (RspFiles++ > 20)
    922       return false;
    923 
    924     // Replace this response file argument with the tokenization of its
    925     // contents.  Nested response files are expanded in subsequent iterations.
    926     // FIXME: If a nested response file uses a relative path, is it relative to
    927     // the cwd of the process or the response file?
    928     SmallVector<const char *, 0> ExpandedArgv;
    929     if (!ExpandResponseFile(Arg + 1, Saver, Tokenizer, ExpandedArgv,
    930                             MarkEOLs)) {
    931       // We couldn't read this file, so we leave it in the argument stream and
    932       // move on.
    933       AllExpanded = false;
    934       ++I;
    935       continue;
    936     }
    937     Argv.erase(Argv.begin() + I);
    938     Argv.insert(Argv.begin() + I, ExpandedArgv.begin(), ExpandedArgv.end());
    939   }
    940   return AllExpanded;
    941 }
    942 
    943 /// ParseEnvironmentOptions - An alternative entry point to the
    944 /// CommandLine library, which allows you to read the program's name
    945 /// from the caller (as PROGNAME) and its command-line arguments from
    946 /// an environment variable (whose name is given in ENVVAR).
    947 ///
    948 void cl::ParseEnvironmentOptions(const char *progName, const char *envVar,
    949                                  const char *Overview) {
    950   // Check args.
    951   assert(progName && "Program name not specified");
    952   assert(envVar && "Environment variable name missing");
    953 
    954   // Get the environment variable they want us to parse options out of.
    955 #ifdef _WIN32
    956   std::wstring wenvVar;
    957   if (!llvm::ConvertUTF8toWide(envVar, wenvVar)) {
    958     assert(false &&
    959            "Unicode conversion of environment variable name failed");
    960     return;
    961   }
    962   const wchar_t *wenvValue = _wgetenv(wenvVar.c_str());
    963   if (!wenvValue)
    964     return;
    965   std::string envValueBuffer;
    966   if (!llvm::convertWideToUTF8(wenvValue, envValueBuffer)) {
    967     assert(false &&
    968            "Unicode conversion of environment variable value failed");
    969     return;
    970   }
    971   const char *envValue = envValueBuffer.c_str();
    972 #else
    973   const char *envValue = getenv(envVar);
    974   if (!envValue)
    975     return;
    976 #endif
    977 
    978   // Get program's "name", which we wouldn't know without the caller
    979   // telling us.
    980   SmallVector<const char *, 20> newArgv;
    981   BumpPtrAllocator A;
    982   StringSaver Saver(A);
    983   newArgv.push_back(Saver.save(progName));
    984 
    985   // Parse the value of the environment variable into a "command line"
    986   // and hand it off to ParseCommandLineOptions().
    987   TokenizeGNUCommandLine(envValue, Saver, newArgv);
    988   int newArgc = static_cast<int>(newArgv.size());
    989   ParseCommandLineOptions(newArgc, &newArgv[0], Overview);
    990 }
    991 
    992 bool cl::ParseCommandLineOptions(int argc, const char *const *argv,
    993                                  const char *Overview, bool IgnoreErrors) {
    994   return GlobalParser->ParseCommandLineOptions(argc, argv, Overview,
    995                                                IgnoreErrors);
    996 }
    997 
    998 void CommandLineParser::ResetAllOptionOccurrences() {
    999   // So that we can parse different command lines multiple times in succession
   1000   // we reset all option values to look like they have never been seen before.
   1001   for (auto SC : RegisteredSubCommands) {
   1002     for (auto &O : SC->OptionsMap)
   1003       O.second->reset();
   1004   }
   1005 }
   1006 
   1007 bool CommandLineParser::ParseCommandLineOptions(int argc,
   1008                                                 const char *const *argv,
   1009                                                 const char *Overview,
   1010                                                 bool IgnoreErrors) {
   1011   assert(hasOptions() && "No options specified!");
   1012 
   1013   // Expand response files.
   1014   SmallVector<const char *, 20> newArgv(argv, argv + argc);
   1015   BumpPtrAllocator A;
   1016   StringSaver Saver(A);
   1017   ExpandResponseFiles(Saver, TokenizeGNUCommandLine, newArgv);
   1018   argv = &newArgv[0];
   1019   argc = static_cast<int>(newArgv.size());
   1020 
   1021   // Copy the program name into ProgName, making sure not to overflow it.
   1022   ProgramName = sys::path::filename(argv[0]);
   1023 
   1024   ProgramOverview = Overview;
   1025   bool ErrorParsing = false;
   1026 
   1027   // Check out the positional arguments to collect information about them.
   1028   unsigned NumPositionalRequired = 0;
   1029 
   1030   // Determine whether or not there are an unlimited number of positionals
   1031   bool HasUnlimitedPositionals = false;
   1032 
   1033   int FirstArg = 1;
   1034   SubCommand *ChosenSubCommand = &*TopLevelSubCommand;
   1035   if (argc >= 2 && argv[FirstArg][0] != '-') {
   1036     // If the first argument specifies a valid subcommand, start processing
   1037     // options from the second argument.
   1038     ChosenSubCommand = LookupSubCommand(argv[FirstArg]);
   1039     if (ChosenSubCommand != &*TopLevelSubCommand)
   1040       FirstArg = 2;
   1041   }
   1042   GlobalParser->ActiveSubCommand = ChosenSubCommand;
   1043 
   1044   assert(ChosenSubCommand);
   1045   auto &ConsumeAfterOpt = ChosenSubCommand->ConsumeAfterOpt;
   1046   auto &PositionalOpts = ChosenSubCommand->PositionalOpts;
   1047   auto &SinkOpts = ChosenSubCommand->SinkOpts;
   1048   auto &OptionsMap = ChosenSubCommand->OptionsMap;
   1049 
   1050   if (ConsumeAfterOpt) {
   1051     assert(PositionalOpts.size() > 0 &&
   1052            "Cannot specify cl::ConsumeAfter without a positional argument!");
   1053   }
   1054   if (!PositionalOpts.empty()) {
   1055 
   1056     // Calculate how many positional values are _required_.
   1057     bool UnboundedFound = false;
   1058     for (size_t i = 0, e = PositionalOpts.size(); i != e; ++i) {
   1059       Option *Opt = PositionalOpts[i];
   1060       if (RequiresValue(Opt))
   1061         ++NumPositionalRequired;
   1062       else if (ConsumeAfterOpt) {
   1063         // ConsumeAfter cannot be combined with "optional" positional options
   1064         // unless there is only one positional argument...
   1065         if (PositionalOpts.size() > 1) {
   1066           if (!IgnoreErrors)
   1067             Opt->error("error - this positional option will never be matched, "
   1068                        "because it does not Require a value, and a "
   1069                        "cl::ConsumeAfter option is active!");
   1070           ErrorParsing = true;
   1071         }
   1072       } else if (UnboundedFound && !Opt->hasArgStr()) {
   1073         // This option does not "require" a value...  Make sure this option is
   1074         // not specified after an option that eats all extra arguments, or this
   1075         // one will never get any!
   1076         //
   1077         if (!IgnoreErrors) {
   1078           Opt->error("error - option can never match, because "
   1079                      "another positional argument will match an "
   1080                      "unbounded number of values, and this option"
   1081                      " does not require a value!");
   1082           errs() << ProgramName << ": CommandLine Error: Option '"
   1083                  << Opt->ArgStr << "' is all messed up!\n";
   1084           errs() << PositionalOpts.size();
   1085         }
   1086         ErrorParsing = true;
   1087       }
   1088       UnboundedFound |= EatsUnboundedNumberOfValues(Opt);
   1089     }
   1090     HasUnlimitedPositionals = UnboundedFound || ConsumeAfterOpt;
   1091   }
   1092 
   1093   // PositionalVals - A vector of "positional" arguments we accumulate into
   1094   // the process at the end.
   1095   //
   1096   SmallVector<std::pair<StringRef, unsigned>, 4> PositionalVals;
   1097 
   1098   // If the program has named positional arguments, and the name has been run
   1099   // across, keep track of which positional argument was named.  Otherwise put
   1100   // the positional args into the PositionalVals list...
   1101   Option *ActivePositionalArg = nullptr;
   1102 
   1103   // Loop over all of the arguments... processing them.
   1104   bool DashDashFound = false; // Have we read '--'?
   1105   for (int i = FirstArg; i < argc; ++i) {
   1106     Option *Handler = nullptr;
   1107     Option *NearestHandler = nullptr;
   1108     std::string NearestHandlerString;
   1109     StringRef Value;
   1110     StringRef ArgName = "";
   1111 
   1112     // Check to see if this is a positional argument.  This argument is
   1113     // considered to be positional if it doesn't start with '-', if it is "-"
   1114     // itself, or if we have seen "--" already.
   1115     //
   1116     if (argv[i][0] != '-' || argv[i][1] == 0 || DashDashFound) {
   1117       // Positional argument!
   1118       if (ActivePositionalArg) {
   1119         ProvidePositionalOption(ActivePositionalArg, argv[i], i);
   1120         continue; // We are done!
   1121       }
   1122 
   1123       if (!PositionalOpts.empty()) {
   1124         PositionalVals.push_back(std::make_pair(argv[i], i));
   1125 
   1126         // All of the positional arguments have been fulfulled, give the rest to
   1127         // the consume after option... if it's specified...
   1128         //
   1129         if (PositionalVals.size() >= NumPositionalRequired && ConsumeAfterOpt) {
   1130           for (++i; i < argc; ++i)
   1131             PositionalVals.push_back(std::make_pair(argv[i], i));
   1132           break; // Handle outside of the argument processing loop...
   1133         }
   1134 
   1135         // Delay processing positional arguments until the end...
   1136         continue;
   1137       }
   1138     } else if (argv[i][0] == '-' && argv[i][1] == '-' && argv[i][2] == 0 &&
   1139                !DashDashFound) {
   1140       DashDashFound = true; // This is the mythical "--"?
   1141       continue;             // Don't try to process it as an argument itself.
   1142     } else if (ActivePositionalArg &&
   1143                (ActivePositionalArg->getMiscFlags() & PositionalEatsArgs)) {
   1144       // If there is a positional argument eating options, check to see if this
   1145       // option is another positional argument.  If so, treat it as an argument,
   1146       // otherwise feed it to the eating positional.
   1147       ArgName = argv[i] + 1;
   1148       // Eat leading dashes.
   1149       while (!ArgName.empty() && ArgName[0] == '-')
   1150         ArgName = ArgName.substr(1);
   1151 
   1152       Handler = LookupOption(*ChosenSubCommand, ArgName, Value);
   1153       if (!Handler || Handler->getFormattingFlag() != cl::Positional) {
   1154         ProvidePositionalOption(ActivePositionalArg, argv[i], i);
   1155         continue; // We are done!
   1156       }
   1157 
   1158     } else { // We start with a '-', must be an argument.
   1159       ArgName = argv[i] + 1;
   1160       // Eat leading dashes.
   1161       while (!ArgName.empty() && ArgName[0] == '-')
   1162         ArgName = ArgName.substr(1);
   1163 
   1164       Handler = LookupOption(*ChosenSubCommand, ArgName, Value);
   1165 
   1166       // Check to see if this "option" is really a prefixed or grouped argument.
   1167       if (!Handler)
   1168         Handler = HandlePrefixedOrGroupedOption(ArgName, Value, ErrorParsing,
   1169                                                 OptionsMap);
   1170 
   1171       // Otherwise, look for the closest available option to report to the user
   1172       // in the upcoming error.
   1173       if (!Handler && SinkOpts.empty())
   1174         NearestHandler =
   1175             LookupNearestOption(ArgName, OptionsMap, NearestHandlerString);
   1176     }
   1177 
   1178     if (!Handler) {
   1179       if (SinkOpts.empty()) {
   1180         if (!IgnoreErrors) {
   1181           errs() << ProgramName << ": Unknown command line argument '"
   1182                  << argv[i] << "'.  Try: '" << argv[0] << " -help'\n";
   1183 
   1184           if (NearestHandler) {
   1185             // If we know a near match, report it as well.
   1186             errs() << ProgramName << ": Did you mean '-" << NearestHandlerString
   1187                    << "'?\n";
   1188           }
   1189         }
   1190 
   1191         ErrorParsing = true;
   1192       } else {
   1193         for (SmallVectorImpl<Option *>::iterator I = SinkOpts.begin(),
   1194                                                  E = SinkOpts.end();
   1195              I != E; ++I)
   1196           (*I)->addOccurrence(i, "", argv[i]);
   1197       }
   1198       continue;
   1199     }
   1200 
   1201     // If this is a named positional argument, just remember that it is the
   1202     // active one...
   1203     if (Handler->getFormattingFlag() == cl::Positional)
   1204       ActivePositionalArg = Handler;
   1205     else
   1206       ErrorParsing |= ProvideOption(Handler, ArgName, Value, argc, argv, i);
   1207   }
   1208 
   1209   // Check and handle positional arguments now...
   1210   if (NumPositionalRequired > PositionalVals.size()) {
   1211     if (!IgnoreErrors) {
   1212       errs() << ProgramName
   1213              << ": Not enough positional command line arguments specified!\n"
   1214              << "Must specify at least " << NumPositionalRequired
   1215              << " positional arguments: See: " << argv[0] << " -help\n";
   1216     }
   1217 
   1218     ErrorParsing = true;
   1219   } else if (!HasUnlimitedPositionals &&
   1220              PositionalVals.size() > PositionalOpts.size()) {
   1221     if (!IgnoreErrors) {
   1222       errs() << ProgramName << ": Too many positional arguments specified!\n"
   1223              << "Can specify at most " << PositionalOpts.size()
   1224              << " positional arguments: See: " << argv[0] << " -help\n";
   1225     }
   1226     ErrorParsing = true;
   1227 
   1228   } else if (!ConsumeAfterOpt) {
   1229     // Positional args have already been handled if ConsumeAfter is specified.
   1230     unsigned ValNo = 0, NumVals = static_cast<unsigned>(PositionalVals.size());
   1231     for (size_t i = 0, e = PositionalOpts.size(); i != e; ++i) {
   1232       if (RequiresValue(PositionalOpts[i])) {
   1233         ProvidePositionalOption(PositionalOpts[i], PositionalVals[ValNo].first,
   1234                                 PositionalVals[ValNo].second);
   1235         ValNo++;
   1236         --NumPositionalRequired; // We fulfilled our duty...
   1237       }
   1238 
   1239       // If we _can_ give this option more arguments, do so now, as long as we
   1240       // do not give it values that others need.  'Done' controls whether the
   1241       // option even _WANTS_ any more.
   1242       //
   1243       bool Done = PositionalOpts[i]->getNumOccurrencesFlag() == cl::Required;
   1244       while (NumVals - ValNo > NumPositionalRequired && !Done) {
   1245         switch (PositionalOpts[i]->getNumOccurrencesFlag()) {
   1246         case cl::Optional:
   1247           Done = true; // Optional arguments want _at most_ one value
   1248         // FALL THROUGH
   1249         case cl::ZeroOrMore: // Zero or more will take all they can get...
   1250         case cl::OneOrMore:  // One or more will take all they can get...
   1251           ProvidePositionalOption(PositionalOpts[i],
   1252                                   PositionalVals[ValNo].first,
   1253                                   PositionalVals[ValNo].second);
   1254           ValNo++;
   1255           break;
   1256         default:
   1257           llvm_unreachable("Internal error, unexpected NumOccurrences flag in "
   1258                            "positional argument processing!");
   1259         }
   1260       }
   1261     }
   1262   } else {
   1263     assert(ConsumeAfterOpt && NumPositionalRequired <= PositionalVals.size());
   1264     unsigned ValNo = 0;
   1265     for (size_t j = 1, e = PositionalOpts.size(); j != e; ++j)
   1266       if (RequiresValue(PositionalOpts[j])) {
   1267         ErrorParsing |= ProvidePositionalOption(PositionalOpts[j],
   1268                                                 PositionalVals[ValNo].first,
   1269                                                 PositionalVals[ValNo].second);
   1270         ValNo++;
   1271       }
   1272 
   1273     // Handle the case where there is just one positional option, and it's
   1274     // optional.  In this case, we want to give JUST THE FIRST option to the
   1275     // positional option and keep the rest for the consume after.  The above
   1276     // loop would have assigned no values to positional options in this case.
   1277     //
   1278     if (PositionalOpts.size() == 1 && ValNo == 0 && !PositionalVals.empty()) {
   1279       ErrorParsing |= ProvidePositionalOption(PositionalOpts[0],
   1280                                               PositionalVals[ValNo].first,
   1281                                               PositionalVals[ValNo].second);
   1282       ValNo++;
   1283     }
   1284 
   1285     // Handle over all of the rest of the arguments to the
   1286     // cl::ConsumeAfter command line option...
   1287     for (; ValNo != PositionalVals.size(); ++ValNo)
   1288       ErrorParsing |=
   1289           ProvidePositionalOption(ConsumeAfterOpt, PositionalVals[ValNo].first,
   1290                                   PositionalVals[ValNo].second);
   1291   }
   1292 
   1293   // Loop over args and make sure all required args are specified!
   1294   for (const auto &Opt : OptionsMap) {
   1295     switch (Opt.second->getNumOccurrencesFlag()) {
   1296     case Required:
   1297     case OneOrMore:
   1298       if (Opt.second->getNumOccurrences() == 0) {
   1299         Opt.second->error("must be specified at least once!");
   1300         ErrorParsing = true;
   1301       }
   1302     // Fall through
   1303     default:
   1304       break;
   1305     }
   1306   }
   1307 
   1308   // Now that we know if -debug is specified, we can use it.
   1309   // Note that if ReadResponseFiles == true, this must be done before the
   1310   // memory allocated for the expanded command line is free()d below.
   1311   DEBUG(dbgs() << "Args: ";
   1312         for (int i = 0; i < argc; ++i) dbgs() << argv[i] << ' ';
   1313         dbgs() << '\n';);
   1314 
   1315   // Free all of the memory allocated to the map.  Command line options may only
   1316   // be processed once!
   1317   MoreHelp.clear();
   1318 
   1319   // If we had an error processing our arguments, don't let the program execute
   1320   if (ErrorParsing) {
   1321     if (!IgnoreErrors)
   1322       exit(1);
   1323     return false;
   1324   }
   1325   return true;
   1326 }
   1327 
   1328 //===----------------------------------------------------------------------===//
   1329 // Option Base class implementation
   1330 //
   1331 
   1332 bool Option::error(const Twine &Message, StringRef ArgName) {
   1333   if (!ArgName.data())
   1334     ArgName = ArgStr;
   1335   if (ArgName.empty())
   1336     errs() << HelpStr; // Be nice for positional arguments
   1337   else
   1338     errs() << GlobalParser->ProgramName << ": for the -" << ArgName;
   1339 
   1340   errs() << " option: " << Message << "\n";
   1341   return true;
   1342 }
   1343 
   1344 bool Option::addOccurrence(unsigned pos, StringRef ArgName, StringRef Value,
   1345                            bool MultiArg) {
   1346   if (!MultiArg)
   1347     NumOccurrences++; // Increment the number of times we have been seen
   1348 
   1349   switch (getNumOccurrencesFlag()) {
   1350   case Optional:
   1351     if (NumOccurrences > 1)
   1352       return error("may only occur zero or one times!", ArgName);
   1353     break;
   1354   case Required:
   1355     if (NumOccurrences > 1)
   1356       return error("must occur exactly one time!", ArgName);
   1357   // Fall through
   1358   case OneOrMore:
   1359   case ZeroOrMore:
   1360   case ConsumeAfter:
   1361     break;
   1362   }
   1363 
   1364   return handleOccurrence(pos, ArgName, Value);
   1365 }
   1366 
   1367 // getValueStr - Get the value description string, using "DefaultMsg" if nothing
   1368 // has been specified yet.
   1369 //
   1370 static StringRef getValueStr(const Option &O, StringRef DefaultMsg) {
   1371   if (O.ValueStr.empty())
   1372     return DefaultMsg;
   1373   return O.ValueStr;
   1374 }
   1375 
   1376 //===----------------------------------------------------------------------===//
   1377 // cl::alias class implementation
   1378 //
   1379 
   1380 // Return the width of the option tag for printing...
   1381 size_t alias::getOptionWidth() const { return ArgStr.size() + 6; }
   1382 
   1383 static void printHelpStr(StringRef HelpStr, size_t Indent,
   1384                          size_t FirstLineIndentedBy) {
   1385   std::pair<StringRef, StringRef> Split = HelpStr.split('\n');
   1386   outs().indent(Indent - FirstLineIndentedBy) << " - " << Split.first << "\n";
   1387   while (!Split.second.empty()) {
   1388     Split = Split.second.split('\n');
   1389     outs().indent(Indent) << Split.first << "\n";
   1390   }
   1391 }
   1392 
   1393 // Print out the option for the alias.
   1394 void alias::printOptionInfo(size_t GlobalWidth) const {
   1395   outs() << "  -" << ArgStr;
   1396   printHelpStr(HelpStr, GlobalWidth, ArgStr.size() + 6);
   1397 }
   1398 
   1399 //===----------------------------------------------------------------------===//
   1400 // Parser Implementation code...
   1401 //
   1402 
   1403 // basic_parser implementation
   1404 //
   1405 
   1406 // Return the width of the option tag for printing...
   1407 size_t basic_parser_impl::getOptionWidth(const Option &O) const {
   1408   size_t Len = O.ArgStr.size();
   1409   if (const char *ValName = getValueName())
   1410     Len += getValueStr(O, ValName).size() + 3;
   1411 
   1412   return Len + 6;
   1413 }
   1414 
   1415 // printOptionInfo - Print out information about this option.  The
   1416 // to-be-maintained width is specified.
   1417 //
   1418 void basic_parser_impl::printOptionInfo(const Option &O,
   1419                                         size_t GlobalWidth) const {
   1420   outs() << "  -" << O.ArgStr;
   1421 
   1422   if (const char *ValName = getValueName())
   1423     outs() << "=<" << getValueStr(O, ValName) << '>';
   1424 
   1425   printHelpStr(O.HelpStr, GlobalWidth, getOptionWidth(O));
   1426 }
   1427 
   1428 void basic_parser_impl::printOptionName(const Option &O,
   1429                                         size_t GlobalWidth) const {
   1430   outs() << "  -" << O.ArgStr;
   1431   outs().indent(GlobalWidth - O.ArgStr.size());
   1432 }
   1433 
   1434 // parser<bool> implementation
   1435 //
   1436 bool parser<bool>::parse(Option &O, StringRef ArgName, StringRef Arg,
   1437                          bool &Value) {
   1438   if (Arg == "" || Arg == "true" || Arg == "TRUE" || Arg == "True" ||
   1439       Arg == "1") {
   1440     Value = true;
   1441     return false;
   1442   }
   1443 
   1444   if (Arg == "false" || Arg == "FALSE" || Arg == "False" || Arg == "0") {
   1445     Value = false;
   1446     return false;
   1447   }
   1448   return O.error("'" + Arg +
   1449                  "' is invalid value for boolean argument! Try 0 or 1");
   1450 }
   1451 
   1452 // parser<boolOrDefault> implementation
   1453 //
   1454 bool parser<boolOrDefault>::parse(Option &O, StringRef ArgName, StringRef Arg,
   1455                                   boolOrDefault &Value) {
   1456   if (Arg == "" || Arg == "true" || Arg == "TRUE" || Arg == "True" ||
   1457       Arg == "1") {
   1458     Value = BOU_TRUE;
   1459     return false;
   1460   }
   1461   if (Arg == "false" || Arg == "FALSE" || Arg == "False" || Arg == "0") {
   1462     Value = BOU_FALSE;
   1463     return false;
   1464   }
   1465 
   1466   return O.error("'" + Arg +
   1467                  "' is invalid value for boolean argument! Try 0 or 1");
   1468 }
   1469 
   1470 // parser<int> implementation
   1471 //
   1472 bool parser<int>::parse(Option &O, StringRef ArgName, StringRef Arg,
   1473                         int &Value) {
   1474   if (Arg.getAsInteger(0, Value))
   1475     return O.error("'" + Arg + "' value invalid for integer argument!");
   1476   return false;
   1477 }
   1478 
   1479 // parser<unsigned> implementation
   1480 //
   1481 bool parser<unsigned>::parse(Option &O, StringRef ArgName, StringRef Arg,
   1482                              unsigned &Value) {
   1483 
   1484   if (Arg.getAsInteger(0, Value))
   1485     return O.error("'" + Arg + "' value invalid for uint argument!");
   1486   return false;
   1487 }
   1488 
   1489 // parser<unsigned long long> implementation
   1490 //
   1491 bool parser<unsigned long long>::parse(Option &O, StringRef ArgName,
   1492                                        StringRef Arg,
   1493                                        unsigned long long &Value) {
   1494 
   1495   if (Arg.getAsInteger(0, Value))
   1496     return O.error("'" + Arg + "' value invalid for uint argument!");
   1497   return false;
   1498 }
   1499 
   1500 // parser<double>/parser<float> implementation
   1501 //
   1502 static bool parseDouble(Option &O, StringRef Arg, double &Value) {
   1503   SmallString<32> TmpStr(Arg.begin(), Arg.end());
   1504   const char *ArgStart = TmpStr.c_str();
   1505   char *End;
   1506   Value = strtod(ArgStart, &End);
   1507   if (*End != 0)
   1508     return O.error("'" + Arg + "' value invalid for floating point argument!");
   1509   return false;
   1510 }
   1511 
   1512 bool parser<double>::parse(Option &O, StringRef ArgName, StringRef Arg,
   1513                            double &Val) {
   1514   return parseDouble(O, Arg, Val);
   1515 }
   1516 
   1517 bool parser<float>::parse(Option &O, StringRef ArgName, StringRef Arg,
   1518                           float &Val) {
   1519   double dVal;
   1520   if (parseDouble(O, Arg, dVal))
   1521     return true;
   1522   Val = (float)dVal;
   1523   return false;
   1524 }
   1525 
   1526 // generic_parser_base implementation
   1527 //
   1528 
   1529 // findOption - Return the option number corresponding to the specified
   1530 // argument string.  If the option is not found, getNumOptions() is returned.
   1531 //
   1532 unsigned generic_parser_base::findOption(const char *Name) {
   1533   unsigned e = getNumOptions();
   1534 
   1535   for (unsigned i = 0; i != e; ++i) {
   1536     if (strcmp(getOption(i), Name) == 0)
   1537       return i;
   1538   }
   1539   return e;
   1540 }
   1541 
   1542 // Return the width of the option tag for printing...
   1543 size_t generic_parser_base::getOptionWidth(const Option &O) const {
   1544   if (O.hasArgStr()) {
   1545     size_t Size = O.ArgStr.size() + 6;
   1546     for (unsigned i = 0, e = getNumOptions(); i != e; ++i)
   1547       Size = std::max(Size, std::strlen(getOption(i)) + 8);
   1548     return Size;
   1549   } else {
   1550     size_t BaseSize = 0;
   1551     for (unsigned i = 0, e = getNumOptions(); i != e; ++i)
   1552       BaseSize = std::max(BaseSize, std::strlen(getOption(i)) + 8);
   1553     return BaseSize;
   1554   }
   1555 }
   1556 
   1557 // printOptionInfo - Print out information about this option.  The
   1558 // to-be-maintained width is specified.
   1559 //
   1560 void generic_parser_base::printOptionInfo(const Option &O,
   1561                                           size_t GlobalWidth) const {
   1562   if (O.hasArgStr()) {
   1563     outs() << "  -" << O.ArgStr;
   1564     printHelpStr(O.HelpStr, GlobalWidth, O.ArgStr.size() + 6);
   1565 
   1566     for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
   1567       size_t NumSpaces = GlobalWidth - strlen(getOption(i)) - 8;
   1568       outs() << "    =" << getOption(i);
   1569       outs().indent(NumSpaces) << " -   " << getDescription(i) << '\n';
   1570     }
   1571   } else {
   1572     if (!O.HelpStr.empty())
   1573       outs() << "  " << O.HelpStr << '\n';
   1574     for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
   1575       const char *Option = getOption(i);
   1576       outs() << "    -" << Option;
   1577       printHelpStr(getDescription(i), GlobalWidth, std::strlen(Option) + 8);
   1578     }
   1579   }
   1580 }
   1581 
   1582 static const size_t MaxOptWidth = 8; // arbitrary spacing for printOptionDiff
   1583 
   1584 // printGenericOptionDiff - Print the value of this option and it's default.
   1585 //
   1586 // "Generic" options have each value mapped to a name.
   1587 void generic_parser_base::printGenericOptionDiff(
   1588     const Option &O, const GenericOptionValue &Value,
   1589     const GenericOptionValue &Default, size_t GlobalWidth) const {
   1590   outs() << "  -" << O.ArgStr;
   1591   outs().indent(GlobalWidth - O.ArgStr.size());
   1592 
   1593   unsigned NumOpts = getNumOptions();
   1594   for (unsigned i = 0; i != NumOpts; ++i) {
   1595     if (Value.compare(getOptionValue(i)))
   1596       continue;
   1597 
   1598     outs() << "= " << getOption(i);
   1599     size_t L = std::strlen(getOption(i));
   1600     size_t NumSpaces = MaxOptWidth > L ? MaxOptWidth - L : 0;
   1601     outs().indent(NumSpaces) << " (default: ";
   1602     for (unsigned j = 0; j != NumOpts; ++j) {
   1603       if (Default.compare(getOptionValue(j)))
   1604         continue;
   1605       outs() << getOption(j);
   1606       break;
   1607     }
   1608     outs() << ")\n";
   1609     return;
   1610   }
   1611   outs() << "= *unknown option value*\n";
   1612 }
   1613 
   1614 // printOptionDiff - Specializations for printing basic value types.
   1615 //
   1616 #define PRINT_OPT_DIFF(T)                                                      \
   1617   void parser<T>::printOptionDiff(const Option &O, T V, OptionValue<T> D,      \
   1618                                   size_t GlobalWidth) const {                  \
   1619     printOptionName(O, GlobalWidth);                                           \
   1620     std::string Str;                                                           \
   1621     {                                                                          \
   1622       raw_string_ostream SS(Str);                                              \
   1623       SS << V;                                                                 \
   1624     }                                                                          \
   1625     outs() << "= " << Str;                                                     \
   1626     size_t NumSpaces =                                                         \
   1627         MaxOptWidth > Str.size() ? MaxOptWidth - Str.size() : 0;               \
   1628     outs().indent(NumSpaces) << " (default: ";                                 \
   1629     if (D.hasValue())                                                          \
   1630       outs() << D.getValue();                                                  \
   1631     else                                                                       \
   1632       outs() << "*no default*";                                                \
   1633     outs() << ")\n";                                                           \
   1634   }
   1635 
   1636 PRINT_OPT_DIFF(bool)
   1637 PRINT_OPT_DIFF(boolOrDefault)
   1638 PRINT_OPT_DIFF(int)
   1639 PRINT_OPT_DIFF(unsigned)
   1640 PRINT_OPT_DIFF(unsigned long long)
   1641 PRINT_OPT_DIFF(double)
   1642 PRINT_OPT_DIFF(float)
   1643 PRINT_OPT_DIFF(char)
   1644 
   1645 void parser<std::string>::printOptionDiff(const Option &O, StringRef V,
   1646                                           const OptionValue<std::string> &D,
   1647                                           size_t GlobalWidth) const {
   1648   printOptionName(O, GlobalWidth);
   1649   outs() << "= " << V;
   1650   size_t NumSpaces = MaxOptWidth > V.size() ? MaxOptWidth - V.size() : 0;
   1651   outs().indent(NumSpaces) << " (default: ";
   1652   if (D.hasValue())
   1653     outs() << D.getValue();
   1654   else
   1655     outs() << "*no default*";
   1656   outs() << ")\n";
   1657 }
   1658 
   1659 // Print a placeholder for options that don't yet support printOptionDiff().
   1660 void basic_parser_impl::printOptionNoValue(const Option &O,
   1661                                            size_t GlobalWidth) const {
   1662   printOptionName(O, GlobalWidth);
   1663   outs() << "= *cannot print option value*\n";
   1664 }
   1665 
   1666 //===----------------------------------------------------------------------===//
   1667 // -help and -help-hidden option implementation
   1668 //
   1669 
   1670 static int OptNameCompare(const std::pair<const char *, Option *> *LHS,
   1671                           const std::pair<const char *, Option *> *RHS) {
   1672   return strcmp(LHS->first, RHS->first);
   1673 }
   1674 
   1675 static int SubNameCompare(const std::pair<const char *, SubCommand *> *LHS,
   1676                           const std::pair<const char *, SubCommand *> *RHS) {
   1677   return strcmp(LHS->first, RHS->first);
   1678 }
   1679 
   1680 // Copy Options into a vector so we can sort them as we like.
   1681 static void sortOpts(StringMap<Option *> &OptMap,
   1682                      SmallVectorImpl<std::pair<const char *, Option *>> &Opts,
   1683                      bool ShowHidden) {
   1684   SmallPtrSet<Option *, 32> OptionSet; // Duplicate option detection.
   1685 
   1686   for (StringMap<Option *>::iterator I = OptMap.begin(), E = OptMap.end();
   1687        I != E; ++I) {
   1688     // Ignore really-hidden options.
   1689     if (I->second->getOptionHiddenFlag() == ReallyHidden)
   1690       continue;
   1691 
   1692     // Unless showhidden is set, ignore hidden flags.
   1693     if (I->second->getOptionHiddenFlag() == Hidden && !ShowHidden)
   1694       continue;
   1695 
   1696     // If we've already seen this option, don't add it to the list again.
   1697     if (!OptionSet.insert(I->second).second)
   1698       continue;
   1699 
   1700     Opts.push_back(
   1701         std::pair<const char *, Option *>(I->getKey().data(), I->second));
   1702   }
   1703 
   1704   // Sort the options list alphabetically.
   1705   array_pod_sort(Opts.begin(), Opts.end(), OptNameCompare);
   1706 }
   1707 
   1708 static void
   1709 sortSubCommands(const SmallPtrSetImpl<SubCommand *> &SubMap,
   1710                 SmallVectorImpl<std::pair<const char *, SubCommand *>> &Subs) {
   1711   for (const auto &S : SubMap) {
   1712     if (S->getName() == nullptr)
   1713       continue;
   1714     Subs.push_back(std::make_pair(S->getName(), S));
   1715   }
   1716   array_pod_sort(Subs.begin(), Subs.end(), SubNameCompare);
   1717 }
   1718 
   1719 namespace {
   1720 
   1721 class HelpPrinter {
   1722 protected:
   1723   const bool ShowHidden;
   1724   typedef SmallVector<std::pair<const char *, Option *>, 128>
   1725       StrOptionPairVector;
   1726   typedef SmallVector<std::pair<const char *, SubCommand *>, 128>
   1727       StrSubCommandPairVector;
   1728   // Print the options. Opts is assumed to be alphabetically sorted.
   1729   virtual void printOptions(StrOptionPairVector &Opts, size_t MaxArgLen) {
   1730     for (size_t i = 0, e = Opts.size(); i != e; ++i)
   1731       Opts[i].second->printOptionInfo(MaxArgLen);
   1732   }
   1733 
   1734   void printSubCommands(StrSubCommandPairVector &Subs, size_t MaxSubLen) {
   1735     for (const auto &S : Subs) {
   1736       outs() << "  " << S.first;
   1737       if (S.second->getDescription()) {
   1738         outs().indent(MaxSubLen - strlen(S.first));
   1739         outs() << " - " << S.second->getDescription();
   1740       }
   1741       outs() << "\n";
   1742     }
   1743   }
   1744 
   1745 public:
   1746   explicit HelpPrinter(bool showHidden) : ShowHidden(showHidden) {}
   1747   virtual ~HelpPrinter() {}
   1748 
   1749   // Invoke the printer.
   1750   void operator=(bool Value) {
   1751     if (!Value)
   1752       return;
   1753 
   1754     SubCommand *Sub = GlobalParser->getActiveSubCommand();
   1755     auto &OptionsMap = Sub->OptionsMap;
   1756     auto &PositionalOpts = Sub->PositionalOpts;
   1757     auto &ConsumeAfterOpt = Sub->ConsumeAfterOpt;
   1758 
   1759     StrOptionPairVector Opts;
   1760     sortOpts(OptionsMap, Opts, ShowHidden);
   1761 
   1762     StrSubCommandPairVector Subs;
   1763     sortSubCommands(GlobalParser->RegisteredSubCommands, Subs);
   1764 
   1765     if (GlobalParser->ProgramOverview)
   1766       outs() << "OVERVIEW: " << GlobalParser->ProgramOverview << "\n";
   1767 
   1768     if (Sub == &*TopLevelSubCommand)
   1769       outs() << "USAGE: " << GlobalParser->ProgramName
   1770              << " [subcommand] [options]";
   1771     else {
   1772       if (Sub->getDescription() != nullptr) {
   1773         outs() << "SUBCOMMAND '" << Sub->getName()
   1774                << "': " << Sub->getDescription() << "\n\n";
   1775       }
   1776       outs() << "USAGE: " << GlobalParser->ProgramName << " " << Sub->getName()
   1777              << " [options]";
   1778     }
   1779 
   1780     for (auto Opt : PositionalOpts) {
   1781       if (Opt->hasArgStr())
   1782         outs() << " --" << Opt->ArgStr;
   1783       outs() << " " << Opt->HelpStr;
   1784     }
   1785 
   1786     // Print the consume after option info if it exists...
   1787     if (ConsumeAfterOpt)
   1788       outs() << " " << ConsumeAfterOpt->HelpStr;
   1789 
   1790     if (Sub == &*TopLevelSubCommand && Subs.size() > 2) {
   1791       // Compute the maximum subcommand length...
   1792       size_t MaxSubLen = 0;
   1793       for (size_t i = 0, e = Subs.size(); i != e; ++i)
   1794         MaxSubLen = std::max(MaxSubLen, strlen(Subs[i].first));
   1795 
   1796       outs() << "\n\n";
   1797       outs() << "SUBCOMMANDS:\n\n";
   1798       printSubCommands(Subs, MaxSubLen);
   1799       outs() << "\n";
   1800       outs() << "  Type \"" << GlobalParser->ProgramName
   1801              << " <subcommand> -help\" to get more help on a specific "
   1802                 "subcommand";
   1803     }
   1804 
   1805     outs() << "\n\n";
   1806 
   1807     // Compute the maximum argument length...
   1808     size_t MaxArgLen = 0;
   1809     for (size_t i = 0, e = Opts.size(); i != e; ++i)
   1810       MaxArgLen = std::max(MaxArgLen, Opts[i].second->getOptionWidth());
   1811 
   1812     outs() << "OPTIONS:\n";
   1813     printOptions(Opts, MaxArgLen);
   1814 
   1815     // Print any extra help the user has declared.
   1816     for (auto I : GlobalParser->MoreHelp)
   1817       outs() << I;
   1818     GlobalParser->MoreHelp.clear();
   1819 
   1820     // Halt the program since help information was printed
   1821     exit(0);
   1822   }
   1823 };
   1824 
   1825 class CategorizedHelpPrinter : public HelpPrinter {
   1826 public:
   1827   explicit CategorizedHelpPrinter(bool showHidden) : HelpPrinter(showHidden) {}
   1828 
   1829   // Helper function for printOptions().
   1830   // It shall return a negative value if A's name should be lexicographically
   1831   // ordered before B's name. It returns a value greater equal zero otherwise.
   1832   static int OptionCategoryCompare(OptionCategory *const *A,
   1833                                    OptionCategory *const *B) {
   1834     return strcmp((*A)->getName(), (*B)->getName());
   1835   }
   1836 
   1837   // Make sure we inherit our base class's operator=()
   1838   using HelpPrinter::operator=;
   1839 
   1840 protected:
   1841   void printOptions(StrOptionPairVector &Opts, size_t MaxArgLen) override {
   1842     std::vector<OptionCategory *> SortedCategories;
   1843     std::map<OptionCategory *, std::vector<Option *>> CategorizedOptions;
   1844 
   1845     // Collect registered option categories into vector in preparation for
   1846     // sorting.
   1847     for (auto I = GlobalParser->RegisteredOptionCategories.begin(),
   1848               E = GlobalParser->RegisteredOptionCategories.end();
   1849          I != E; ++I) {
   1850       SortedCategories.push_back(*I);
   1851     }
   1852 
   1853     // Sort the different option categories alphabetically.
   1854     assert(SortedCategories.size() > 0 && "No option categories registered!");
   1855     array_pod_sort(SortedCategories.begin(), SortedCategories.end(),
   1856                    OptionCategoryCompare);
   1857 
   1858     // Create map to empty vectors.
   1859     for (std::vector<OptionCategory *>::const_iterator
   1860              I = SortedCategories.begin(),
   1861              E = SortedCategories.end();
   1862          I != E; ++I)
   1863       CategorizedOptions[*I] = std::vector<Option *>();
   1864 
   1865     // Walk through pre-sorted options and assign into categories.
   1866     // Because the options are already alphabetically sorted the
   1867     // options within categories will also be alphabetically sorted.
   1868     for (size_t I = 0, E = Opts.size(); I != E; ++I) {
   1869       Option *Opt = Opts[I].second;
   1870       assert(CategorizedOptions.count(Opt->Category) > 0 &&
   1871              "Option has an unregistered category");
   1872       CategorizedOptions[Opt->Category].push_back(Opt);
   1873     }
   1874 
   1875     // Now do printing.
   1876     for (std::vector<OptionCategory *>::const_iterator
   1877              Category = SortedCategories.begin(),
   1878              E = SortedCategories.end();
   1879          Category != E; ++Category) {
   1880       // Hide empty categories for -help, but show for -help-hidden.
   1881       const auto &CategoryOptions = CategorizedOptions[*Category];
   1882       bool IsEmptyCategory = CategoryOptions.empty();
   1883       if (!ShowHidden && IsEmptyCategory)
   1884         continue;
   1885 
   1886       // Print category information.
   1887       outs() << "\n";
   1888       outs() << (*Category)->getName() << ":\n";
   1889 
   1890       // Check if description is set.
   1891       if ((*Category)->getDescription() != nullptr)
   1892         outs() << (*Category)->getDescription() << "\n\n";
   1893       else
   1894         outs() << "\n";
   1895 
   1896       // When using -help-hidden explicitly state if the category has no
   1897       // options associated with it.
   1898       if (IsEmptyCategory) {
   1899         outs() << "  This option category has no options.\n";
   1900         continue;
   1901       }
   1902       // Loop over the options in the category and print.
   1903       for (const Option *Opt : CategoryOptions)
   1904         Opt->printOptionInfo(MaxArgLen);
   1905     }
   1906   }
   1907 };
   1908 
   1909 // This wraps the Uncategorizing and Categorizing printers and decides
   1910 // at run time which should be invoked.
   1911 class HelpPrinterWrapper {
   1912 private:
   1913   HelpPrinter &UncategorizedPrinter;
   1914   CategorizedHelpPrinter &CategorizedPrinter;
   1915 
   1916 public:
   1917   explicit HelpPrinterWrapper(HelpPrinter &UncategorizedPrinter,
   1918                               CategorizedHelpPrinter &CategorizedPrinter)
   1919       : UncategorizedPrinter(UncategorizedPrinter),
   1920         CategorizedPrinter(CategorizedPrinter) {}
   1921 
   1922   // Invoke the printer.
   1923   void operator=(bool Value);
   1924 };
   1925 
   1926 } // End anonymous namespace
   1927 
   1928 // Declare the four HelpPrinter instances that are used to print out help, or
   1929 // help-hidden as an uncategorized list or in categories.
   1930 static HelpPrinter UncategorizedNormalPrinter(false);
   1931 static HelpPrinter UncategorizedHiddenPrinter(true);
   1932 static CategorizedHelpPrinter CategorizedNormalPrinter(false);
   1933 static CategorizedHelpPrinter CategorizedHiddenPrinter(true);
   1934 
   1935 // Declare HelpPrinter wrappers that will decide whether or not to invoke
   1936 // a categorizing help printer
   1937 static HelpPrinterWrapper WrappedNormalPrinter(UncategorizedNormalPrinter,
   1938                                                CategorizedNormalPrinter);
   1939 static HelpPrinterWrapper WrappedHiddenPrinter(UncategorizedHiddenPrinter,
   1940                                                CategorizedHiddenPrinter);
   1941 
   1942 // Define a category for generic options that all tools should have.
   1943 static cl::OptionCategory GenericCategory("Generic Options");
   1944 
   1945 // Define uncategorized help printers.
   1946 // -help-list is hidden by default because if Option categories are being used
   1947 // then -help behaves the same as -help-list.
   1948 static cl::opt<HelpPrinter, true, parser<bool>> HLOp(
   1949     "help-list",
   1950     cl::desc("Display list of available options (-help-list-hidden for more)"),
   1951     cl::location(UncategorizedNormalPrinter), cl::Hidden, cl::ValueDisallowed,
   1952     cl::cat(GenericCategory), cl::sub(*AllSubCommands));
   1953 
   1954 static cl::opt<HelpPrinter, true, parser<bool>>
   1955     HLHOp("help-list-hidden", cl::desc("Display list of all available options"),
   1956           cl::location(UncategorizedHiddenPrinter), cl::Hidden,
   1957           cl::ValueDisallowed, cl::cat(GenericCategory),
   1958           cl::sub(*AllSubCommands));
   1959 
   1960 // Define uncategorized/categorized help printers. These printers change their
   1961 // behaviour at runtime depending on whether one or more Option categories have
   1962 // been declared.
   1963 static cl::opt<HelpPrinterWrapper, true, parser<bool>>
   1964     HOp("help", cl::desc("Display available options (-help-hidden for more)"),
   1965         cl::location(WrappedNormalPrinter), cl::ValueDisallowed,
   1966         cl::cat(GenericCategory), cl::sub(*AllSubCommands));
   1967 
   1968 static cl::opt<HelpPrinterWrapper, true, parser<bool>>
   1969     HHOp("help-hidden", cl::desc("Display all available options"),
   1970          cl::location(WrappedHiddenPrinter), cl::Hidden, cl::ValueDisallowed,
   1971          cl::cat(GenericCategory), cl::sub(*AllSubCommands));
   1972 
   1973 static cl::opt<bool> PrintOptions(
   1974     "print-options",
   1975     cl::desc("Print non-default options after command line parsing"),
   1976     cl::Hidden, cl::init(false), cl::cat(GenericCategory),
   1977     cl::sub(*AllSubCommands));
   1978 
   1979 static cl::opt<bool> PrintAllOptions(
   1980     "print-all-options",
   1981     cl::desc("Print all option values after command line parsing"), cl::Hidden,
   1982     cl::init(false), cl::cat(GenericCategory), cl::sub(*AllSubCommands));
   1983 
   1984 void HelpPrinterWrapper::operator=(bool Value) {
   1985   if (!Value)
   1986     return;
   1987 
   1988   // Decide which printer to invoke. If more than one option category is
   1989   // registered then it is useful to show the categorized help instead of
   1990   // uncategorized help.
   1991   if (GlobalParser->RegisteredOptionCategories.size() > 1) {
   1992     // unhide -help-list option so user can have uncategorized output if they
   1993     // want it.
   1994     HLOp.setHiddenFlag(NotHidden);
   1995 
   1996     CategorizedPrinter = true; // Invoke categorized printer
   1997   } else
   1998     UncategorizedPrinter = true; // Invoke uncategorized printer
   1999 }
   2000 
   2001 // Print the value of each option.
   2002 void cl::PrintOptionValues() { GlobalParser->printOptionValues(); }
   2003 
   2004 void CommandLineParser::printOptionValues() {
   2005   if (!PrintOptions && !PrintAllOptions)
   2006     return;
   2007 
   2008   SmallVector<std::pair<const char *, Option *>, 128> Opts;
   2009   sortOpts(ActiveSubCommand->OptionsMap, Opts, /*ShowHidden*/ true);
   2010 
   2011   // Compute the maximum argument length...
   2012   size_t MaxArgLen = 0;
   2013   for (size_t i = 0, e = Opts.size(); i != e; ++i)
   2014     MaxArgLen = std::max(MaxArgLen, Opts[i].second->getOptionWidth());
   2015 
   2016   for (size_t i = 0, e = Opts.size(); i != e; ++i)
   2017     Opts[i].second->printOptionValue(MaxArgLen, PrintAllOptions);
   2018 }
   2019 
   2020 static void (*OverrideVersionPrinter)() = nullptr;
   2021 
   2022 static std::vector<void (*)()> *ExtraVersionPrinters = nullptr;
   2023 
   2024 namespace {
   2025 class VersionPrinter {
   2026 public:
   2027   void print() {
   2028     raw_ostream &OS = outs();
   2029 #ifdef PACKAGE_VENDOR
   2030     OS << PACKAGE_VENDOR << " ";
   2031 #else
   2032     OS << "LLVM (http://llvm.org/):\n  ";
   2033 #endif
   2034     OS << PACKAGE_NAME << " version " << PACKAGE_VERSION;
   2035 #ifdef LLVM_VERSION_INFO
   2036     OS << " " << LLVM_VERSION_INFO;
   2037 #endif
   2038     OS << "\n  ";
   2039 #ifndef __OPTIMIZE__
   2040     OS << "DEBUG build";
   2041 #else
   2042     OS << "Optimized build";
   2043 #endif
   2044 #ifndef NDEBUG
   2045     OS << " with assertions";
   2046 #endif
   2047     std::string CPU = sys::getHostCPUName();
   2048     if (CPU == "generic")
   2049       CPU = "(unknown)";
   2050     OS << ".\n"
   2051        << "  Default target: " << sys::getDefaultTargetTriple() << '\n'
   2052        << "  Host CPU: " << CPU << '\n';
   2053   }
   2054   void operator=(bool OptionWasSpecified) {
   2055     if (!OptionWasSpecified)
   2056       return;
   2057 
   2058     if (OverrideVersionPrinter != nullptr) {
   2059       (*OverrideVersionPrinter)();
   2060       exit(0);
   2061     }
   2062     print();
   2063 
   2064     // Iterate over any registered extra printers and call them to add further
   2065     // information.
   2066     if (ExtraVersionPrinters != nullptr) {
   2067       outs() << '\n';
   2068       for (std::vector<void (*)()>::iterator I = ExtraVersionPrinters->begin(),
   2069                                              E = ExtraVersionPrinters->end();
   2070            I != E; ++I)
   2071         (*I)();
   2072     }
   2073 
   2074     exit(0);
   2075   }
   2076 };
   2077 } // End anonymous namespace
   2078 
   2079 // Define the --version option that prints out the LLVM version for the tool
   2080 static VersionPrinter VersionPrinterInstance;
   2081 
   2082 static cl::opt<VersionPrinter, true, parser<bool>>
   2083     VersOp("version", cl::desc("Display the version of this program"),
   2084            cl::location(VersionPrinterInstance), cl::ValueDisallowed,
   2085            cl::cat(GenericCategory));
   2086 
   2087 // Utility function for printing the help message.
   2088 void cl::PrintHelpMessage(bool Hidden, bool Categorized) {
   2089   // This looks weird, but it actually prints the help message. The Printers are
   2090   // types of HelpPrinter and the help gets printed when its operator= is
   2091   // invoked. That's because the "normal" usages of the help printer is to be
   2092   // assigned true/false depending on whether -help or -help-hidden was given or
   2093   // not.  Since we're circumventing that we have to make it look like -help or
   2094   // -help-hidden were given, so we assign true.
   2095 
   2096   if (!Hidden && !Categorized)
   2097     UncategorizedNormalPrinter = true;
   2098   else if (!Hidden && Categorized)
   2099     CategorizedNormalPrinter = true;
   2100   else if (Hidden && !Categorized)
   2101     UncategorizedHiddenPrinter = true;
   2102   else
   2103     CategorizedHiddenPrinter = true;
   2104 }
   2105 
   2106 /// Utility function for printing version number.
   2107 void cl::PrintVersionMessage() { VersionPrinterInstance.print(); }
   2108 
   2109 void cl::SetVersionPrinter(void (*func)()) { OverrideVersionPrinter = func; }
   2110 
   2111 void cl::AddExtraVersionPrinter(void (*func)()) {
   2112   if (!ExtraVersionPrinters)
   2113     ExtraVersionPrinters = new std::vector<void (*)()>;
   2114 
   2115   ExtraVersionPrinters->push_back(func);
   2116 }
   2117 
   2118 StringMap<Option *> &cl::getRegisteredOptions(SubCommand &Sub) {
   2119   auto &Subs = GlobalParser->RegisteredSubCommands;
   2120   (void)Subs;
   2121   assert(std::find(Subs.begin(), Subs.end(), &Sub) != Subs.end());
   2122   return Sub.OptionsMap;
   2123 }
   2124 
   2125 void cl::HideUnrelatedOptions(cl::OptionCategory &Category, SubCommand &Sub) {
   2126   for (auto &I : Sub.OptionsMap) {
   2127     if (I.second->Category != &Category &&
   2128         I.second->Category != &GenericCategory)
   2129       I.second->setHiddenFlag(cl::ReallyHidden);
   2130   }
   2131 }
   2132 
   2133 void cl::HideUnrelatedOptions(ArrayRef<const cl::OptionCategory *> Categories,
   2134                               SubCommand &Sub) {
   2135   auto CategoriesBegin = Categories.begin();
   2136   auto CategoriesEnd = Categories.end();
   2137   for (auto &I : Sub.OptionsMap) {
   2138     if (std::find(CategoriesBegin, CategoriesEnd, I.second->Category) ==
   2139             CategoriesEnd &&
   2140         I.second->Category != &GenericCategory)
   2141       I.second->setHiddenFlag(cl::ReallyHidden);
   2142   }
   2143 }
   2144 
   2145 void cl::ResetCommandLineParser() { GlobalParser->reset(); }
   2146 void cl::ResetAllOptionOccurrences() {
   2147   GlobalParser->ResetAllOptionOccurrences();
   2148 }
   2149 
   2150 void LLVMParseCommandLineOptions(int argc, const char *const *argv,
   2151                                  const char *Overview) {
   2152   llvm::cl::ParseCommandLineOptions(argc, argv, Overview, true);
   2153 }
   2154