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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(ArrayRef<Info> OptionInfos, bool IgnoreCase)
     88     : OptionInfos(OptionInfos), IgnoreCase(IgnoreCase), TheInputOptionID(0),
     89       TheUnknownOptionID(0), FirstSearchableIndex(0) {
     90   // Explicitly zero initialize the error to work around a bug in array
     91   // value-initialization on MinGW with gcc 4.3.5.
     92 
     93   // Find start of normal options.
     94   for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
     95     unsigned Kind = getInfo(i + 1).Kind;
     96     if (Kind == Option::InputClass) {
     97       assert(!TheInputOptionID && "Cannot have multiple input options!");
     98       TheInputOptionID = getInfo(i + 1).ID;
     99     } else if (Kind == Option::UnknownClass) {
    100       assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
    101       TheUnknownOptionID = getInfo(i + 1).ID;
    102     } else if (Kind != Option::GroupClass) {
    103       FirstSearchableIndex = i;
    104       break;
    105     }
    106   }
    107   assert(FirstSearchableIndex != 0 && "No searchable options?");
    108 
    109 #ifndef NDEBUG
    110   // Check that everything after the first searchable option is a
    111   // regular option class.
    112   for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
    113     Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
    114     assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
    115             Kind != Option::GroupClass) &&
    116            "Special options should be defined first!");
    117   }
    118 
    119   // Check that options are in order.
    120   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
    121     if (!(getInfo(i) < getInfo(i + 1))) {
    122       getOption(i).dump();
    123       getOption(i + 1).dump();
    124       llvm_unreachable("Options are not in order!");
    125     }
    126   }
    127 #endif
    128 
    129   // Build prefixes.
    130   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
    131                 i != e; ++i) {
    132     if (const char *const *P = getInfo(i).Prefixes) {
    133       for (; *P != nullptr; ++P) {
    134         PrefixesUnion.insert(*P);
    135       }
    136     }
    137   }
    138 
    139   // Build prefix chars.
    140   for (llvm::StringSet<>::const_iterator I = PrefixesUnion.begin(),
    141                                          E = PrefixesUnion.end(); I != E; ++I) {
    142     StringRef Prefix = I->getKey();
    143     for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
    144                                    C != CE; ++C)
    145       if (std::find(PrefixChars.begin(), PrefixChars.end(), *C)
    146             == PrefixChars.end())
    147         PrefixChars.push_back(*C);
    148   }
    149 }
    150 
    151 OptTable::~OptTable() {
    152 }
    153 
    154 const Option OptTable::getOption(OptSpecifier Opt) const {
    155   unsigned id = Opt.getID();
    156   if (id == 0)
    157     return Option(nullptr, nullptr);
    158   assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
    159   return Option(&getInfo(id), this);
    160 }
    161 
    162 static bool isInput(const llvm::StringSet<> &Prefixes, StringRef Arg) {
    163   if (Arg == "-")
    164     return true;
    165   for (llvm::StringSet<>::const_iterator I = Prefixes.begin(),
    166                                          E = Prefixes.end(); I != E; ++I)
    167     if (Arg.startswith(I->getKey()))
    168       return false;
    169   return true;
    170 }
    171 
    172 /// \returns Matched size. 0 means no match.
    173 static unsigned matchOption(const OptTable::Info *I, StringRef Str,
    174                             bool IgnoreCase) {
    175   for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
    176     StringRef Prefix(*Pre);
    177     if (Str.startswith(Prefix)) {
    178       StringRef Rest = Str.substr(Prefix.size());
    179       bool Matched = IgnoreCase
    180           ? Rest.startswith_lower(I->Name)
    181           : Rest.startswith(I->Name);
    182       if (Matched)
    183         return Prefix.size() + StringRef(I->Name).size();
    184     }
    185   }
    186   return 0;
    187 }
    188 
    189 Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
    190                            unsigned FlagsToInclude,
    191                            unsigned FlagsToExclude) const {
    192   unsigned Prev = Index;
    193   const char *Str = Args.getArgString(Index);
    194 
    195   // Anything that doesn't start with PrefixesUnion is an input, as is '-'
    196   // itself.
    197   if (isInput(PrefixesUnion, Str))
    198     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
    199 
    200   const Info *Start = OptionInfos.begin() + FirstSearchableIndex;
    201   const Info *End = OptionInfos.end();
    202   StringRef Name = StringRef(Str).ltrim(PrefixChars);
    203 
    204   // Search for the first next option which could be a prefix.
    205   Start = std::lower_bound(Start, End, Name.data());
    206 
    207   // Options are stored in sorted order, with '\0' at the end of the
    208   // alphabet. Since the only options which can accept a string must
    209   // prefix it, we iteratively search for the next option which could
    210   // be a prefix.
    211   //
    212   // FIXME: This is searching much more than necessary, but I am
    213   // blanking on the simplest way to make it fast. We can solve this
    214   // problem when we move to TableGen.
    215   for (; Start != End; ++Start) {
    216     unsigned ArgSize = 0;
    217     // Scan for first option which is a proper prefix.
    218     for (; Start != End; ++Start)
    219       if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
    220         break;
    221     if (Start == End)
    222       break;
    223 
    224     Option Opt(Start, this);
    225 
    226     if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
    227       continue;
    228     if (Opt.hasFlag(FlagsToExclude))
    229       continue;
    230 
    231     // See if this option matches.
    232     if (Arg *A = Opt.accept(Args, Index, ArgSize))
    233       return A;
    234 
    235     // Otherwise, see if this argument was missing values.
    236     if (Prev != Index)
    237       return nullptr;
    238   }
    239 
    240   // If we failed to find an option and this arg started with /, then it's
    241   // probably an input path.
    242   if (Str[0] == '/')
    243     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
    244 
    245   return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
    246 }
    247 
    248 InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
    249                                  unsigned &MissingArgIndex,
    250                                  unsigned &MissingArgCount,
    251                                  unsigned FlagsToInclude,
    252                                  unsigned FlagsToExclude) const {
    253   InputArgList Args(ArgArr.begin(), ArgArr.end());
    254 
    255   // FIXME: Handle '@' args (or at least error on them).
    256 
    257   MissingArgIndex = MissingArgCount = 0;
    258   unsigned Index = 0, End = ArgArr.size();
    259   while (Index < End) {
    260     // Ingore nullptrs, they are response file's EOL markers
    261     if (Args.getArgString(Index) == nullptr) {
    262       ++Index;
    263       continue;
    264     }
    265     // Ignore empty arguments (other things may still take them as arguments).
    266     StringRef Str = Args.getArgString(Index);
    267     if (Str == "") {
    268       ++Index;
    269       continue;
    270     }
    271 
    272     unsigned Prev = Index;
    273     Arg *A = ParseOneArg(Args, Index, FlagsToInclude, FlagsToExclude);
    274     assert(Index > Prev && "Parser failed to consume argument.");
    275 
    276     // Check for missing argument error.
    277     if (!A) {
    278       assert(Index >= End && "Unexpected parser error.");
    279       assert(Index - Prev - 1 && "No missing arguments!");
    280       MissingArgIndex = Prev;
    281       MissingArgCount = Index - Prev - 1;
    282       break;
    283     }
    284 
    285     Args.append(A);
    286   }
    287 
    288   return Args;
    289 }
    290 
    291 static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
    292   const Option O = Opts.getOption(Id);
    293   std::string Name = O.getPrefixedName();
    294 
    295   // Add metavar, if used.
    296   switch (O.getKind()) {
    297   case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
    298     llvm_unreachable("Invalid option with help text.");
    299 
    300   case Option::MultiArgClass:
    301     if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
    302       // For MultiArgs, metavar is full list of all argument names.
    303       Name += ' ';
    304       Name += MetaVarName;
    305     }
    306     else {
    307       // For MultiArgs<N>, if metavar not supplied, print <value> N times.
    308       for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
    309         Name += " <value>";
    310       }
    311     }
    312     break;
    313 
    314   case Option::FlagClass:
    315     break;
    316 
    317   case Option::SeparateClass: case Option::JoinedOrSeparateClass:
    318   case Option::RemainingArgsClass:
    319     Name += ' ';
    320     // FALLTHROUGH
    321   case Option::JoinedClass: case Option::CommaJoinedClass:
    322   case Option::JoinedAndSeparateClass:
    323     if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
    324       Name += MetaVarName;
    325     else
    326       Name += "<value>";
    327     break;
    328   }
    329 
    330   return Name;
    331 }
    332 
    333 static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
    334                                 std::vector<std::pair<std::string,
    335                                 const char*> > &OptionHelp) {
    336   OS << Title << ":\n";
    337 
    338   // Find the maximum option length.
    339   unsigned OptionFieldWidth = 0;
    340   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
    341     // Skip titles.
    342     if (!OptionHelp[i].second)
    343       continue;
    344 
    345     // Limit the amount of padding we are willing to give up for alignment.
    346     unsigned Length = OptionHelp[i].first.size();
    347     if (Length <= 23)
    348       OptionFieldWidth = std::max(OptionFieldWidth, Length);
    349   }
    350 
    351   const unsigned InitialPad = 2;
    352   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
    353     const std::string &Option = OptionHelp[i].first;
    354     int Pad = OptionFieldWidth - int(Option.size());
    355     OS.indent(InitialPad) << Option;
    356 
    357     // Break on long option names.
    358     if (Pad < 0) {
    359       OS << "\n";
    360       Pad = OptionFieldWidth + InitialPad;
    361     }
    362     OS.indent(Pad + 1) << OptionHelp[i].second << '\n';
    363   }
    364 }
    365 
    366 static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
    367   unsigned GroupID = Opts.getOptionGroupID(Id);
    368 
    369   // If not in a group, return the default help group.
    370   if (!GroupID)
    371     return "OPTIONS";
    372 
    373   // Abuse the help text of the option groups to store the "help group"
    374   // name.
    375   //
    376   // FIXME: Split out option groups.
    377   if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
    378     return GroupHelp;
    379 
    380   // Otherwise keep looking.
    381   return getOptionHelpGroup(Opts, GroupID);
    382 }
    383 
    384 void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
    385                          bool ShowHidden) const {
    386   PrintHelp(OS, Name, Title, /*Include*/ 0, /*Exclude*/
    387             (ShowHidden ? 0 : HelpHidden));
    388 }
    389 
    390 
    391 void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
    392                          unsigned FlagsToInclude,
    393                          unsigned FlagsToExclude) const {
    394   OS << "OVERVIEW: " << Title << "\n";
    395   OS << '\n';
    396   OS << "USAGE: " << Name << " [options] <inputs>\n";
    397   OS << '\n';
    398 
    399   // Render help text into a map of group-name to a list of (option, help)
    400   // pairs.
    401   typedef std::map<std::string,
    402                  std::vector<std::pair<std::string, const char*> > > helpmap_ty;
    403   helpmap_ty GroupedOptionHelp;
    404 
    405   for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
    406     unsigned Id = i + 1;
    407 
    408     // FIXME: Split out option groups.
    409     if (getOptionKind(Id) == Option::GroupClass)
    410       continue;
    411 
    412     unsigned Flags = getInfo(Id).Flags;
    413     if (FlagsToInclude && !(Flags & FlagsToInclude))
    414       continue;
    415     if (Flags & FlagsToExclude)
    416       continue;
    417 
    418     if (const char *Text = getOptionHelpText(Id)) {
    419       const char *HelpGroup = getOptionHelpGroup(*this, Id);
    420       const std::string &OptName = getOptionHelpName(*this, Id);
    421       GroupedOptionHelp[HelpGroup].push_back(std::make_pair(OptName, Text));
    422     }
    423   }
    424 
    425   for (helpmap_ty::iterator it = GroupedOptionHelp .begin(),
    426          ie = GroupedOptionHelp.end(); it != ie; ++it) {
    427     if (it != GroupedOptionHelp .begin())
    428       OS << "\n";
    429     PrintHelpOptionList(OS, it->first, it->second);
    430   }
    431 
    432   OS.flush();
    433 }
    434