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      1 //===--- OptTable.cpp - Option Table 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 #include "llvm/Option/OptTable.h"
     11 #include "llvm/Option/Arg.h"
     12 #include "llvm/Option/ArgList.h"
     13 #include "llvm/Option/Option.h"
     14 #include "llvm/Support/ErrorHandling.h"
     15 #include "llvm/Support/raw_ostream.h"
     16 #include <algorithm>
     17 #include <cctype>
     18 #include <map>
     19 
     20 using namespace llvm;
     21 using namespace llvm::opt;
     22 
     23 namespace llvm {
     24 namespace opt {
     25 
     26 // Ordering on Info. The ordering is *almost* case-insensitive lexicographic,
     27 // with an exceptions. '\0' comes at the end of the alphabet instead of the
     28 // beginning (thus options precede any other options which prefix them).
     29 static int StrCmpOptionNameIgnoreCase(const char *A, const char *B) {
     30   const char *X = A, *Y = B;
     31   char a = tolower(*A), b = tolower(*B);
     32   while (a == b) {
     33     if (a == '\0')
     34       return 0;
     35 
     36     a = tolower(*++X);
     37     b = tolower(*++Y);
     38   }
     39 
     40   if (a == '\0') // A is a prefix of B.
     41     return 1;
     42   if (b == '\0') // B is a prefix of A.
     43     return -1;
     44 
     45   // Otherwise lexicographic.
     46   return (a < b) ? -1 : 1;
     47 }
     48 
     49 #ifndef NDEBUG
     50 static int StrCmpOptionName(const char *A, const char *B) {
     51   if (int N = StrCmpOptionNameIgnoreCase(A, B))
     52     return N;
     53   return strcmp(A, B);
     54 }
     55 
     56 static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
     57   if (&A == &B)
     58     return false;
     59 
     60   if (int N = StrCmpOptionName(A.Name, B.Name))
     61     return N < 0;
     62 
     63   for (const char * const *APre = A.Prefixes,
     64                   * const *BPre = B.Prefixes;
     65                           *APre != nullptr && *BPre != nullptr; ++APre, ++BPre){
     66     if (int N = StrCmpOptionName(*APre, *BPre))
     67       return N < 0;
     68   }
     69 
     70   // Names are the same, check that classes are in order; exactly one
     71   // should be joined, and it should succeed the other.
     72   assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
     73          "Unexpected classes for options with same name.");
     74   return B.Kind == Option::JoinedClass;
     75 }
     76 #endif
     77 
     78 // Support lower_bound between info and an option name.
     79 static inline bool operator<(const OptTable::Info &I, const char *Name) {
     80   return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
     81 }
     82 }
     83 }
     84 
     85 OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
     86 
     87 OptTable::OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos,
     88                    bool _IgnoreCase)
     89   : OptionInfos(_OptionInfos),
     90     NumOptionInfos(_NumOptionInfos),
     91     IgnoreCase(_IgnoreCase),
     92     TheInputOptionID(0),
     93     TheUnknownOptionID(0),
     94     FirstSearchableIndex(0)
     95 {
     96   // Explicitly zero initialize the error to work around a bug in array
     97   // value-initialization on MinGW with gcc 4.3.5.
     98 
     99   // Find start of normal options.
    100   for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
    101     unsigned Kind = getInfo(i + 1).Kind;
    102     if (Kind == Option::InputClass) {
    103       assert(!TheInputOptionID && "Cannot have multiple input options!");
    104       TheInputOptionID = getInfo(i + 1).ID;
    105     } else if (Kind == Option::UnknownClass) {
    106       assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
    107       TheUnknownOptionID = getInfo(i + 1).ID;
    108     } else if (Kind != Option::GroupClass) {
    109       FirstSearchableIndex = i;
    110       break;
    111     }
    112   }
    113   assert(FirstSearchableIndex != 0 && "No searchable options?");
    114 
    115 #ifndef NDEBUG
    116   // Check that everything after the first searchable option is a
    117   // regular option class.
    118   for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
    119     Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
    120     assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
    121             Kind != Option::GroupClass) &&
    122            "Special options should be defined first!");
    123   }
    124 
    125   // Check that options are in order.
    126   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
    127     if (!(getInfo(i) < getInfo(i + 1))) {
    128       getOption(i).dump();
    129       getOption(i + 1).dump();
    130       llvm_unreachable("Options are not in order!");
    131     }
    132   }
    133 #endif
    134 
    135   // Build prefixes.
    136   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
    137                 i != e; ++i) {
    138     if (const char *const *P = getInfo(i).Prefixes) {
    139       for (; *P != nullptr; ++P) {
    140         PrefixesUnion.insert(*P);
    141       }
    142     }
    143   }
    144 
    145   // Build prefix chars.
    146   for (llvm::StringSet<>::const_iterator I = PrefixesUnion.begin(),
    147                                          E = PrefixesUnion.end(); I != E; ++I) {
    148     StringRef Prefix = I->getKey();
    149     for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
    150                                    C != CE; ++C)
    151       if (std::find(PrefixChars.begin(), PrefixChars.end(), *C)
    152             == PrefixChars.end())
    153         PrefixChars.push_back(*C);
    154   }
    155 }
    156 
    157 OptTable::~OptTable() {
    158 }
    159 
    160 const Option OptTable::getOption(OptSpecifier Opt) const {
    161   unsigned id = Opt.getID();
    162   if (id == 0)
    163     return Option(nullptr, nullptr);
    164   assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
    165   return Option(&getInfo(id), this);
    166 }
    167 
    168 static bool isInput(const llvm::StringSet<> &Prefixes, StringRef Arg) {
    169   if (Arg == "-")
    170     return true;
    171   for (llvm::StringSet<>::const_iterator I = Prefixes.begin(),
    172                                          E = Prefixes.end(); I != E; ++I)
    173     if (Arg.startswith(I->getKey()))
    174       return false;
    175   return true;
    176 }
    177 
    178 /// \returns Matched size. 0 means no match.
    179 static unsigned matchOption(const OptTable::Info *I, StringRef Str,
    180                             bool IgnoreCase) {
    181   for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
    182     StringRef Prefix(*Pre);
    183     if (Str.startswith(Prefix)) {
    184       StringRef Rest = Str.substr(Prefix.size());
    185       bool Matched = IgnoreCase
    186           ? Rest.startswith_lower(I->Name)
    187           : Rest.startswith(I->Name);
    188       if (Matched)
    189         return Prefix.size() + StringRef(I->Name).size();
    190     }
    191   }
    192   return 0;
    193 }
    194 
    195 Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
    196                            unsigned FlagsToInclude,
    197                            unsigned FlagsToExclude) const {
    198   unsigned Prev = Index;
    199   const char *Str = Args.getArgString(Index);
    200 
    201   // Anything that doesn't start with PrefixesUnion is an input, as is '-'
    202   // itself.
    203   if (isInput(PrefixesUnion, Str))
    204     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
    205 
    206   const Info *Start = OptionInfos + FirstSearchableIndex;
    207   const Info *End = OptionInfos + getNumOptions();
    208   StringRef Name = StringRef(Str).ltrim(PrefixChars);
    209 
    210   // Search for the first next option which could be a prefix.
    211   Start = std::lower_bound(Start, End, Name.data());
    212 
    213   // Options are stored in sorted order, with '\0' at the end of the
    214   // alphabet. Since the only options which can accept a string must
    215   // prefix it, we iteratively search for the next option which could
    216   // be a prefix.
    217   //
    218   // FIXME: This is searching much more than necessary, but I am
    219   // blanking on the simplest way to make it fast. We can solve this
    220   // problem when we move to TableGen.
    221   for (; Start != End; ++Start) {
    222     unsigned ArgSize = 0;
    223     // Scan for first option which is a proper prefix.
    224     for (; Start != End; ++Start)
    225       if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
    226         break;
    227     if (Start == End)
    228       break;
    229 
    230     Option Opt(Start, this);
    231 
    232     if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
    233       continue;
    234     if (Opt.hasFlag(FlagsToExclude))
    235       continue;
    236 
    237     // See if this option matches.
    238     if (Arg *A = Opt.accept(Args, Index, ArgSize))
    239       return A;
    240 
    241     // Otherwise, see if this argument was missing values.
    242     if (Prev != Index)
    243       return nullptr;
    244   }
    245 
    246   // If we failed to find an option and this arg started with /, then it's
    247   // probably an input path.
    248   if (Str[0] == '/')
    249     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
    250 
    251   return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
    252 }
    253 
    254 InputArgList *OptTable::ParseArgs(const char *const *ArgBegin,
    255                                   const char *const *ArgEnd,
    256                                   unsigned &MissingArgIndex,
    257                                   unsigned &MissingArgCount,
    258                                   unsigned FlagsToInclude,
    259                                   unsigned FlagsToExclude) const {
    260   InputArgList *Args = new InputArgList(ArgBegin, ArgEnd);
    261 
    262   // FIXME: Handle '@' args (or at least error on them).
    263 
    264   MissingArgIndex = MissingArgCount = 0;
    265   unsigned Index = 0, End = ArgEnd - ArgBegin;
    266   while (Index < End) {
    267     // Ignore empty arguments (other things may still take them as arguments).
    268     StringRef Str = Args->getArgString(Index);
    269     if (Str == "") {
    270       ++Index;
    271       continue;
    272     }
    273 
    274     unsigned Prev = Index;
    275     Arg *A = ParseOneArg(*Args, Index, FlagsToInclude, FlagsToExclude);
    276     assert(Index > Prev && "Parser failed to consume argument.");
    277 
    278     // Check for missing argument error.
    279     if (!A) {
    280       assert(Index >= End && "Unexpected parser error.");
    281       assert(Index - Prev - 1 && "No missing arguments!");
    282       MissingArgIndex = Prev;
    283       MissingArgCount = Index - Prev - 1;
    284       break;
    285     }
    286 
    287     Args->append(A);
    288   }
    289 
    290   return Args;
    291 }
    292 
    293 static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
    294   const Option O = Opts.getOption(Id);
    295   std::string Name = O.getPrefixedName();
    296 
    297   // Add metavar, if used.
    298   switch (O.getKind()) {
    299   case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
    300     llvm_unreachable("Invalid option with help text.");
    301 
    302   case Option::MultiArgClass:
    303     llvm_unreachable("Cannot print metavar for this kind of option.");
    304 
    305   case Option::FlagClass:
    306     break;
    307 
    308   case Option::SeparateClass: case Option::JoinedOrSeparateClass:
    309   case Option::RemainingArgsClass:
    310     Name += ' ';
    311     // FALLTHROUGH
    312   case Option::JoinedClass: case Option::CommaJoinedClass:
    313   case Option::JoinedAndSeparateClass:
    314     if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
    315       Name += MetaVarName;
    316     else
    317       Name += "<value>";
    318     break;
    319   }
    320 
    321   return Name;
    322 }
    323 
    324 static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
    325                                 std::vector<std::pair<std::string,
    326                                 const char*> > &OptionHelp) {
    327   OS << Title << ":\n";
    328 
    329   // Find the maximum option length.
    330   unsigned OptionFieldWidth = 0;
    331   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
    332     // Skip titles.
    333     if (!OptionHelp[i].second)
    334       continue;
    335 
    336     // Limit the amount of padding we are willing to give up for alignment.
    337     unsigned Length = OptionHelp[i].first.size();
    338     if (Length <= 23)
    339       OptionFieldWidth = std::max(OptionFieldWidth, Length);
    340   }
    341 
    342   const unsigned InitialPad = 2;
    343   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
    344     const std::string &Option = OptionHelp[i].first;
    345     int Pad = OptionFieldWidth - int(Option.size());
    346     OS.indent(InitialPad) << Option;
    347 
    348     // Break on long option names.
    349     if (Pad < 0) {
    350       OS << "\n";
    351       Pad = OptionFieldWidth + InitialPad;
    352     }
    353     OS.indent(Pad + 1) << OptionHelp[i].second << '\n';
    354   }
    355 }
    356 
    357 static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
    358   unsigned GroupID = Opts.getOptionGroupID(Id);
    359 
    360   // If not in a group, return the default help group.
    361   if (!GroupID)
    362     return "OPTIONS";
    363 
    364   // Abuse the help text of the option groups to store the "help group"
    365   // name.
    366   //
    367   // FIXME: Split out option groups.
    368   if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
    369     return GroupHelp;
    370 
    371   // Otherwise keep looking.
    372   return getOptionHelpGroup(Opts, GroupID);
    373 }
    374 
    375 void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
    376                          bool ShowHidden) const {
    377   PrintHelp(OS, Name, Title, /*Include*/ 0, /*Exclude*/
    378             (ShowHidden ? 0 : HelpHidden));
    379 }
    380 
    381 
    382 void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
    383                          unsigned FlagsToInclude,
    384                          unsigned FlagsToExclude) const {
    385   OS << "OVERVIEW: " << Title << "\n";
    386   OS << '\n';
    387   OS << "USAGE: " << Name << " [options] <inputs>\n";
    388   OS << '\n';
    389 
    390   // Render help text into a map of group-name to a list of (option, help)
    391   // pairs.
    392   typedef std::map<std::string,
    393                  std::vector<std::pair<std::string, const char*> > > helpmap_ty;
    394   helpmap_ty GroupedOptionHelp;
    395 
    396   for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
    397     unsigned Id = i + 1;
    398 
    399     // FIXME: Split out option groups.
    400     if (getOptionKind(Id) == Option::GroupClass)
    401       continue;
    402 
    403     unsigned Flags = getInfo(Id).Flags;
    404     if (FlagsToInclude && !(Flags & FlagsToInclude))
    405       continue;
    406     if (Flags & FlagsToExclude)
    407       continue;
    408 
    409     if (const char *Text = getOptionHelpText(Id)) {
    410       const char *HelpGroup = getOptionHelpGroup(*this, Id);
    411       const std::string &OptName = getOptionHelpName(*this, Id);
    412       GroupedOptionHelp[HelpGroup].push_back(std::make_pair(OptName, Text));
    413     }
    414   }
    415 
    416   for (helpmap_ty::iterator it = GroupedOptionHelp .begin(),
    417          ie = GroupedOptionHelp.end(); it != ie; ++it) {
    418     if (it != GroupedOptionHelp .begin())
    419       OS << "\n";
    420     PrintHelpOptionList(OS, it->first, it->second);
    421   }
    422 
    423   OS.flush();
    424 }
    425