lib/Option/OptTable.cpp

   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/ADT/STLExtras.h"
  11 #include "llvm/ADT/StringRef.h"
  12 #include "llvm/ADT/StringSet.h"
  13 #include "llvm/Option/Arg.h"
  14 #include "llvm/Option/ArgList.h"
  15 #include "llvm/Option/Option.h"
  16 #include "llvm/Option/OptSpecifier.h"
  17 #include "llvm/Option/OptTable.h"
  18 #include "llvm/Support/Compiler.h"
  19 #include "llvm/Support/ErrorHandling.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 #include <algorithm>
  22 #include <cassert>
  23 #include <cctype>
  24 #include <cstring>
  25 #include <map>
  26 #include <string>
  27 #include <utility>
  28 #include <vector>
  29
  30 using namespace llvm;
  31 using namespace llvm::opt;
  32
  33 namespace llvm {
  34 namespace opt {
  35
  36 // Ordering on Info. The ordering is *almost* case-insensitive lexicographic,
  37 // with an exception. '\0' comes at the end of the alphabet instead of the
  38 // beginning (thus options precede any other options which prefix them).
  39 static int StrCmpOptionNameIgnoreCase(const char *A, const char *B) {
  40   const char *X = A, *Y = B;
  41   char a = tolower(*A), b = tolower(*B);
  42   while (a == b) {
  43     if (a == '\0')
  44       return 0;
  45
  46     a = tolower(*++X);
  47     b = tolower(*++Y);
  48   }
  49
  50   if (a == '\0') // A is a prefix of B.
  51     return 1;
  52   if (b == '\0') // B is a prefix of A.
  53     return -1;
  54
  55   // Otherwise lexicographic.
  56   return (a < b) ? -1 : 1;
  57 }
  58
  59 #ifndef NDEBUG
  60 static int StrCmpOptionName(const char *A, const char *B) {
  61   if (int N = StrCmpOptionNameIgnoreCase(A, B))
  62     return N;
  63   return strcmp(A, B);
  64 }
  65
  66 static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
  67   if (&A == &B)
  68     return false;
  69
  70   if (int N = StrCmpOptionName(A.Name, B.Name))
  71     return N < 0;
  72
  73   for (const char * const *APre = A.Prefixes,
  74                   * const *BPre = B.Prefixes;
  75                           *APre != nullptr && *BPre != nullptr; ++APre, ++BPre){
  76     if (int N = StrCmpOptionName(*APre, *BPre))
  77       return N < 0;
  78   }
  79
  80   // Names are the same, check that classes are in order; exactly one
  81   // should be joined, and it should succeed the other.
  82   assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
  83          "Unexpected classes for options with same name.");
  84   return B.Kind == Option::JoinedClass;
  85 }
  86 #endif
  87
  88 // Support lower_bound between info and an option name.
  89 static inline bool operator<(const OptTable::Info &I, const char *Name) {
  90   return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
  91 }
  92
  93 } // end namespace opt
  94 } // end namespace llvm
  95
  96 OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
  97
  98 OptTable::OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase)
  99     : OptionInfos(OptionInfos), IgnoreCase(IgnoreCase) {
 100   // Explicitly zero initialize the error to work around a bug in array
 101   // value-initialization on MinGW with gcc 4.3.5.
 102
 103   // Find start of normal options.
 104   for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
 105     unsigned Kind = getInfo(i + 1).Kind;
 106     if (Kind == Option::InputClass) {
 107       assert(!TheInputOptionID && "Cannot have multiple input options!");
 108       TheInputOptionID = getInfo(i + 1).ID;
 109     } else if (Kind == Option::UnknownClass) {
 110       assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
 111       TheUnknownOptionID = getInfo(i + 1).ID;
 112     } else if (Kind != Option::GroupClass) {
 113       FirstSearchableIndex = i;
 114       break;
 115     }
 116   }
 117   assert(FirstSearchableIndex != 0 && "No searchable options?");
 118
 119 #ifndef NDEBUG
 120   // Check that everything after the first searchable option is a
 121   // regular option class.
 122   for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
 123     Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
 124     assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
 125             Kind != Option::GroupClass) &&
 126            "Special options should be defined first!");
 127   }
 128
 129   // Check that options are in order.
 130   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
 131     if (!(getInfo(i) < getInfo(i + 1))) {
 132       getOption(i).dump();
 133       getOption(i + 1).dump();
 134       llvm_unreachable("Options are not in order!");
 135     }
 136   }
 137 #endif
 138
 139   // Build prefixes.
 140   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
 141                 i != e; ++i) {
 142     if (const char *const *P = getInfo(i).Prefixes) {
 143       for (; *P != nullptr; ++P) {
 144         PrefixesUnion.insert(*P);
 145       }
 146     }
 147   }
 148
 149   // Build prefix chars.
 150   for (StringSet<>::const_iterator I = PrefixesUnion.begin(),
 151                                    E = PrefixesUnion.end(); I != E; ++I) {
 152     StringRef Prefix = I->getKey();
 153     for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
 154                                    C != CE; ++C)
 155       if (!is_contained(PrefixChars, *C))
 156         PrefixChars.push_back(*C);
 157   }
 158 }
 159
 160 OptTable::~OptTable() = default;
 161
 162 const Option OptTable::getOption(OptSpecifier Opt) const {
 163   unsigned id = Opt.getID();
 164   if (id == 0)
 165     return Option(nullptr, nullptr);
 166   assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
 167   return Option(&getInfo(id), this);
 168 }
 169
 170 static bool isInput(const StringSet<> &Prefixes, StringRef Arg) {
 171   if (Arg == "-")
 172     return true;
 173   for (StringSet<>::const_iterator I = Prefixes.begin(),
 174                                    E = Prefixes.end(); I != E; ++I)
 175     if (Arg.startswith(I->getKey()))
 176       return false;
 177   return true;
 178 }
 179
 180 /// \returns Matched size. 0 means no match.
 181 static unsigned matchOption(const OptTable::Info *I, StringRef Str,
 182                             bool IgnoreCase) {
 183   for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
 184     StringRef Prefix(*Pre);
 185     if (Str.startswith(Prefix)) {
 186       StringRef Rest = Str.substr(Prefix.size());
 187       bool Matched = IgnoreCase
 188           ? Rest.startswith_lower(I->Name)
 189           : Rest.startswith(I->Name);
 190       if (Matched)
 191         return Prefix.size() + StringRef(I->Name).size();
 192     }
 193   }
 194   return 0;
 195 }
 196
 197 // Returns true if one of the Prefixes + In.Names matches Option
 198 static bool optionMatches(const OptTable::Info &In, StringRef Option) {
 199   if (In.Prefixes)
 200     for (size_t I = 0; In.Prefixes[I]; I++)
 201       if (Option == std::string(In.Prefixes[I]) + In.Name)
 202         return true;
 203   return false;
 204 }
 205
 206 // This function is for flag value completion.
 207 // Eg. When "-stdlib=" and "l" was passed to this function, it will return
 208 // appropiriate values for stdlib, which starts with l.
 209 std::vector<std::string>
 210 OptTable::suggestValueCompletions(StringRef Option, StringRef Arg) const {
 211   // Search all options and return possible values.
 212   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 213     const Info &In = OptionInfos[I];
 214     if (!In.Values || !optionMatches(In, Option))
 215       continue;
 216
 217     SmallVector<StringRef, 8> Candidates;
 218     StringRef(In.Values).split(Candidates, ",", -1, false);
 219
 220     std::vector<std::string> Result;
 221     for (StringRef Val : Candidates)
 222       if (Val.startswith(Arg) && Arg.compare(Val))
 223         Result.push_back(Val);
 224     return Result;
 225   }
 226   return {};
 227 }
 228
 229 std::vector<std::string>
 230 OptTable::findByPrefix(StringRef Cur, unsigned short DisableFlags) const {
 231   std::vector<std::string> Ret;
 232   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 233     const Info &In = OptionInfos[I];
 234     if (!In.Prefixes || (!In.HelpText && !In.GroupID))
 235       continue;
 236     if (In.Flags & DisableFlags)
 237       continue;
 238
 239     for (int I = 0; In.Prefixes[I]; I++) {
 240       std::string S = std::string(In.Prefixes[I]) + std::string(In.Name) + "\t";
 241       if (In.HelpText)
 242         S += In.HelpText;
 243       if (StringRef(S).startswith(Cur) && S.compare(std::string(Cur) + "\t"))
 244         Ret.push_back(S);
 245     }
 246   }
 247   return Ret;
 248 }
 249
 250 unsigned OptTable::findNearest(StringRef Option, std::string &NearestString,
 251                                unsigned FlagsToInclude, unsigned FlagsToExclude,
 252                                unsigned MinimumLength) const {
 253   assert(!Option.empty());
 254
 255   // Consider each option as a candidate, finding the closest match.
 256   unsigned BestDistance = UINT_MAX;
 257   for (const Info &CandidateInfo :
 258        ArrayRef<Info>(OptionInfos).drop_front(FirstSearchableIndex)) {
 259     StringRef CandidateName = CandidateInfo.Name;
 260
 261     // Ignore option candidates with empty names, such as "--", or names
 262     // that do not meet the minimum length.
 263     if (CandidateName.empty() || CandidateName.size() < MinimumLength)
 264       continue;
 265
 266     // If FlagsToInclude were specified, ignore options that don't include
 267     // those flags.
 268     if (FlagsToInclude && !(CandidateInfo.Flags & FlagsToInclude))
 269       continue;
 270     // Ignore options that contain the FlagsToExclude.
 271     if (CandidateInfo.Flags & FlagsToExclude)
 272       continue;
 273
 274     // Ignore positional argument option candidates (which do not
 275     // have prefixes).
 276     if (!CandidateInfo.Prefixes)
 277       continue;
 278     // Find the most appropriate prefix. For example, if a user asks for
 279     // "--helm", suggest "--help" over "-help".
 280     StringRef Prefix = CandidateInfo.Prefixes[0];
 281     for (int P = 1; CandidateInfo.Prefixes[P]; P++) {
 282       if (Option.startswith(CandidateInfo.Prefixes[P]))
 283         Prefix = CandidateInfo.Prefixes[P];
 284     }
 285
 286     // Check if the candidate ends with a character commonly used when
 287     // delimiting an option from its value, such as '=' or ':'. If it does,
 288     // attempt to split the given option based on that delimiter.
 289     std::string Delimiter = "";
 290     char Last = CandidateName.back();
 291     if (Last == '=' || Last == ':')
 292       Delimiter = std::string(1, Last);
 293
 294     StringRef LHS, RHS;
 295     if (Delimiter.empty())
 296       LHS = Option;
 297     else
 298       std::tie(LHS, RHS) = Option.split(Last);
 299
 300     std::string NormalizedName =
 301         (LHS.drop_front(Prefix.size()) + Delimiter).str();
 302     unsigned Distance =
 303         CandidateName.edit_distance(NormalizedName, /*AllowReplacements=*/true,
 304                                     /*MaxEditDistance=*/BestDistance);
 305     if (Distance < BestDistance) {
 306       BestDistance = Distance;
 307       NearestString = (Prefix + CandidateName + RHS).str();
 308     }
 309   }
 310   return BestDistance;
 311 }
 312
 313 bool OptTable::addValues(const char *Option, const char *Values) {
 314   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 315     Info &In = OptionInfos[I];
 316     if (optionMatches(In, Option)) {
 317       In.Values = Values;
 318       return true;
 319     }
 320   }
 321   return false;
 322 }
 323
 324 Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
 325                            unsigned FlagsToInclude,
 326                            unsigned FlagsToExclude) const {
 327   unsigned Prev = Index;
 328   const char *Str = Args.getArgString(Index);
 329
 330   // Anything that doesn't start with PrefixesUnion is an input, as is '-'
 331   // itself.
 332   if (isInput(PrefixesUnion, Str))
 333     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 334
 335   const Info *Start = OptionInfos.data() + FirstSearchableIndex;
 336   const Info *End = OptionInfos.data() + OptionInfos.size();
 337   StringRef Name = StringRef(Str).ltrim(PrefixChars);
 338
 339   // Search for the first next option which could be a prefix.
 340   Start = std::lower_bound(Start, End, Name.data());
 341
 342   // Options are stored in sorted order, with '\0' at the end of the
 343   // alphabet. Since the only options which can accept a string must
 344   // prefix it, we iteratively search for the next option which could
 345   // be a prefix.
 346   //
 347   // FIXME: This is searching much more than necessary, but I am
 348   // blanking on the simplest way to make it fast. We can solve this
 349   // problem when we move to TableGen.
 350   for (; Start != End; ++Start) {
 351     unsigned ArgSize = 0;
 352     // Scan for first option which is a proper prefix.
 353     for (; Start != End; ++Start)
 354       if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
 355         break;
 356     if (Start == End)
 357       break;
 358
 359     Option Opt(Start, this);
 360
 361     if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
 362       continue;
 363     if (Opt.hasFlag(FlagsToExclude))
 364       continue;
 365
 366     // See if this option matches.
 367     if (Arg *A = Opt.accept(Args, Index, ArgSize))
 368       return A;
 369
 370     // Otherwise, see if this argument was missing values.
 371     if (Prev != Index)
 372       return nullptr;
 373   }
 374
 375   // If we failed to find an option and this arg started with /, then it's
 376   // probably an input path.
 377   if (Str[0] == '/')
 378     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 379
 380   return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
 381 }
 382
 383 InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
 384                                  unsigned &MissingArgIndex,
 385                                  unsigned &MissingArgCount,
 386                                  unsigned FlagsToInclude,
 387                                  unsigned FlagsToExclude) const {
 388   InputArgList Args(ArgArr.begin(), ArgArr.end());
 389
 390   // FIXME: Handle '@' args (or at least error on them).
 391
 392   MissingArgIndex = MissingArgCount = 0;
 393   unsigned Index = 0, End = ArgArr.size();
 394   while (Index < End) {
 395     // Ingore nullptrs, they are response file's EOL markers
 396     if (Args.getArgString(Index) == nullptr) {
 397       ++Index;
 398       continue;
 399     }
 400     // Ignore empty arguments (other things may still take them as arguments).
 401     StringRef Str = Args.getArgString(Index);
 402     if (Str == "") {
 403       ++Index;
 404       continue;
 405     }
 406
 407     unsigned Prev = Index;
 408     Arg *A = ParseOneArg(Args, Index, FlagsToInclude, FlagsToExclude);
 409     assert(Index > Prev && "Parser failed to consume argument.");
 410
 411     // Check for missing argument error.
 412     if (!A) {
 413       assert(Index >= End && "Unexpected parser error.");
 414       assert(Index - Prev - 1 && "No missing arguments!");
 415       MissingArgIndex = Prev;
 416       MissingArgCount = Index - Prev - 1;
 417       break;
 418     }
 419
 420     Args.append(A);
 421   }
 422
 423   return Args;
 424 }
 425
 426 static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
 427   const Option O = Opts.getOption(Id);
 428   std::string Name = O.getPrefixedName();
 429
 430   // Add metavar, if used.
 431   switch (O.getKind()) {
 432   case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
 433     llvm_unreachable("Invalid option with help text.");
 434
 435   case Option::MultiArgClass:
 436     if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
 437       // For MultiArgs, metavar is full list of all argument names.
 438       Name += ' ';
 439       Name += MetaVarName;
 440     }
 441     else {
 442       // For MultiArgs<N>, if metavar not supplied, print <value> N times.
 443       for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
 444         Name += " <value>";
 445       }
 446     }
 447     break;
 448
 449   case Option::FlagClass:
 450     break;
 451
 452   case Option::ValuesClass:
 453     break;
 454
 455   case Option::SeparateClass: case Option::JoinedOrSeparateClass:
 456   case Option::RemainingArgsClass: case Option::RemainingArgsJoinedClass:
 457     Name += ' ';
 458     LLVM_FALLTHROUGH;
 459   case Option::JoinedClass: case Option::CommaJoinedClass:
 460   case Option::JoinedAndSeparateClass:
 461     if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
 462       Name += MetaVarName;
 463     else
 464       Name += "<value>";
 465     break;
 466   }
 467
 468   return Name;
 469 }
 470
 471 namespace {
 472 struct OptionInfo {
 473   std::string Name;
 474   StringRef HelpText;
 475 };
 476 } // namespace
 477
 478 static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
 479                                 std::vector<OptionInfo> &OptionHelp) {
 480   OS << Title << ":\n";
 481
 482   // Find the maximum option length.
 483   unsigned OptionFieldWidth = 0;
 484   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
 485     // Limit the amount of padding we are willing to give up for alignment.
 486     unsigned Length = OptionHelp[i].Name.size();
 487     if (Length <= 23)
 488       OptionFieldWidth = std::max(OptionFieldWidth, Length);
 489   }
 490
 491   const unsigned InitialPad = 2;
 492   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
 493     const std::string &Option = OptionHelp[i].Name;
 494     int Pad = OptionFieldWidth - int(Option.size());
 495     OS.indent(InitialPad) << Option;
 496
 497     // Break on long option names.
 498     if (Pad < 0) {
 499       OS << "\n";
 500       Pad = OptionFieldWidth + InitialPad;
 501     }
 502     OS.indent(Pad + 1) << OptionHelp[i].HelpText << '\n';
 503   }
 504 }
 505
 506 static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
 507   unsigned GroupID = Opts.getOptionGroupID(Id);
 508
 509   // If not in a group, return the default help group.
 510   if (!GroupID)
 511     return "OPTIONS";
 512
 513   // Abuse the help text of the option groups to store the "help group"
 514   // name.
 515   //
 516   // FIXME: Split out option groups.
 517   if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
 518     return GroupHelp;
 519
 520   // Otherwise keep looking.
 521   return getOptionHelpGroup(Opts, GroupID);
 522 }
 523
 524 void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
 525                          bool ShowHidden, bool ShowAllAliases) const {
 526   PrintHelp(OS, Usage, Title, /*Include*/ 0, /*Exclude*/
 527             (ShowHidden ? 0 : HelpHidden), ShowAllAliases);
 528 }
 529
 530 void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
 531                          unsigned FlagsToInclude, unsigned FlagsToExclude,
 532                          bool ShowAllAliases) const {
 533   OS << "OVERVIEW: " << Title << "\n\n";
 534   OS << "USAGE: " << Usage << "\n\n";
 535
 536   // Render help text into a map of group-name to a list of (option, help)
 537   // pairs.
 538   std::map<std::string, std::vector<OptionInfo>> GroupedOptionHelp;
 539
 540   for (unsigned Id = 1, e = getNumOptions() + 1; Id != e; ++Id) {
 541     // FIXME: Split out option groups.
 542     if (getOptionKind(Id) == Option::GroupClass)
 543       continue;
 544
 545     unsigned Flags = getInfo(Id).Flags;
 546     if (FlagsToInclude && !(Flags & FlagsToInclude))
 547       continue;
 548     if (Flags & FlagsToExclude)
 549       continue;
 550
 551     // If an alias doesn't have a help text, show a help text for the aliased
 552     // option instead.
 553     const char *HelpText = getOptionHelpText(Id);
 554     if (!HelpText && ShowAllAliases) {
 555       const Option Alias = getOption(Id).getAlias();
 556       if (Alias.isValid())
 557         HelpText = getOptionHelpText(Alias.getID());
 558     }
 559
 560     if (HelpText) {
 561       const char *HelpGroup = getOptionHelpGroup(*this, Id);
 562       const std::string &OptName = getOptionHelpName(*this, Id);
 563       GroupedOptionHelp[HelpGroup].push_back({OptName, HelpText});
 564     }
 565   }
 566
 567   for (auto& OptionGroup : GroupedOptionHelp) {
 568     if (OptionGroup.first != GroupedOptionHelp.begin()->first)
 569       OS << "\n";
 570     PrintHelpOptionList(OS, OptionGroup.first, OptionGroup.second);
 571   }
 572
 573   OS.flush();
 574 }