lib/Option/OptTable.cpp

   1 //===- OptTable.cpp - Option Table Implementation -------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ADT/STLExtras.h"
  10 #include "llvm/ADT/StringRef.h"
  11 #include "llvm/ADT/StringSet.h"
  12 #include "llvm/Option/Arg.h"
  13 #include "llvm/Option/ArgList.h"
  14 #include "llvm/Option/Option.h"
  15 #include "llvm/Option/OptSpecifier.h"
  16 #include "llvm/Option/OptTable.h"
  17 #include "llvm/Support/Compiler.h"
  18 #include "llvm/Support/ErrorHandling.h"
  19 #include "llvm/Support/raw_ostream.h"
  20 #include <algorithm>
  21 #include <cassert>
  22 #include <cctype>
  23 #include <cstring>
  24 #include <map>
  25 #include <string>
  26 #include <utility>
  27 #include <vector>
  28
  29 using namespace llvm;
  30 using namespace llvm::opt;
  31
  32 namespace llvm {
  33 namespace opt {
  34
  35 // Ordering on Info. The ordering is *almost* case-insensitive lexicographic,
  36 // with an exception. '\0' comes at the end of the alphabet instead of the
  37 // beginning (thus options precede any other options which prefix them).
  38 static int StrCmpOptionNameIgnoreCase(const char *A, const char *B) {
  39   const char *X = A, *Y = B;
  40   char a = tolower(*A), b = tolower(*B);
  41   while (a == b) {
  42     if (a == '\0')
  43       return 0;
  44
  45     a = tolower(*++X);
  46     b = tolower(*++Y);
  47   }
  48
  49   if (a == '\0') // A is a prefix of B.
  50     return 1;
  51   if (b == '\0') // B is a prefix of A.
  52     return -1;
  53
  54   // Otherwise lexicographic.
  55   return (a < b) ? -1 : 1;
  56 }
  57
  58 #ifndef NDEBUG
  59 static int StrCmpOptionName(const char *A, const char *B) {
  60   if (int N = StrCmpOptionNameIgnoreCase(A, B))
  61     return N;
  62   return strcmp(A, B);
  63 }
  64
  65 static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
  66   if (&A == &B)
  67     return false;
  68
  69   if (int N = StrCmpOptionName(A.Name, B.Name))
  70     return N < 0;
  71
  72   for (const char * const *APre = A.Prefixes,
  73                   * const *BPre = B.Prefixes;
  74                           *APre != nullptr && *BPre != nullptr; ++APre, ++BPre){
  75     if (int N = StrCmpOptionName(*APre, *BPre))
  76       return N < 0;
  77   }
  78
  79   // Names are the same, check that classes are in order; exactly one
  80   // should be joined, and it should succeed the other.
  81   assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
  82          "Unexpected classes for options with same name.");
  83   return B.Kind == Option::JoinedClass;
  84 }
  85 #endif
  86
  87 // Support lower_bound between info and an option name.
  88 static inline bool operator<(const OptTable::Info &I, const char *Name) {
  89   return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
  90 }
  91
  92 } // end namespace opt
  93 } // end namespace llvm
  94
  95 OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
  96
  97 OptTable::OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase)
  98     : OptionInfos(OptionInfos), IgnoreCase(IgnoreCase) {
  99   // Explicitly zero initialize the error to work around a bug in array
 100   // value-initialization on MinGW with gcc 4.3.5.
 101
 102   // Find start of normal options.
 103   for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
 104     unsigned Kind = getInfo(i + 1).Kind;
 105     if (Kind == Option::InputClass) {
 106       assert(!TheInputOptionID && "Cannot have multiple input options!");
 107       TheInputOptionID = getInfo(i + 1).ID;
 108     } else if (Kind == Option::UnknownClass) {
 109       assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
 110       TheUnknownOptionID = getInfo(i + 1).ID;
 111     } else if (Kind != Option::GroupClass) {
 112       FirstSearchableIndex = i;
 113       break;
 114     }
 115   }
 116   assert(FirstSearchableIndex != 0 && "No searchable options?");
 117
 118 #ifndef NDEBUG
 119   // Check that everything after the first searchable option is a
 120   // regular option class.
 121   for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
 122     Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
 123     assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
 124             Kind != Option::GroupClass) &&
 125            "Special options should be defined first!");
 126   }
 127
 128   // Check that options are in order.
 129   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
 130     if (!(getInfo(i) < getInfo(i + 1))) {
 131       getOption(i).dump();
 132       getOption(i + 1).dump();
 133       llvm_unreachable("Options are not in order!");
 134     }
 135   }
 136 #endif
 137
 138   // Build prefixes.
 139   for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
 140                 i != e; ++i) {
 141     if (const char *const *P = getInfo(i).Prefixes) {
 142       for (; *P != nullptr; ++P) {
 143         PrefixesUnion.insert(*P);
 144       }
 145     }
 146   }
 147
 148   // Build prefix chars.
 149   for (StringSet<>::const_iterator I = PrefixesUnion.begin(),
 150                                    E = PrefixesUnion.end(); I != E; ++I) {
 151     StringRef Prefix = I->getKey();
 152     for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
 153                                    C != CE; ++C)
 154       if (!is_contained(PrefixChars, *C))
 155         PrefixChars.push_back(*C);
 156   }
 157 }
 158
 159 OptTable::~OptTable() = default;
 160
 161 const Option OptTable::getOption(OptSpecifier Opt) const {
 162   unsigned id = Opt.getID();
 163   if (id == 0)
 164     return Option(nullptr, nullptr);
 165   assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
 166   return Option(&getInfo(id), this);
 167 }
 168
 169 static bool isInput(const StringSet<> &Prefixes, StringRef Arg) {
 170   if (Arg == "-")
 171     return true;
 172   for (StringSet<>::const_iterator I = Prefixes.begin(),
 173                                    E = Prefixes.end(); I != E; ++I)
 174     if (Arg.startswith(I->getKey()))
 175       return false;
 176   return true;
 177 }
 178
 179 /// \returns Matched size. 0 means no match.
 180 static unsigned matchOption(const OptTable::Info *I, StringRef Str,
 181                             bool IgnoreCase) {
 182   for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
 183     StringRef Prefix(*Pre);
 184     if (Str.startswith(Prefix)) {
 185       StringRef Rest = Str.substr(Prefix.size());
 186       bool Matched = IgnoreCase
 187           ? Rest.startswith_lower(I->Name)
 188           : Rest.startswith(I->Name);
 189       if (Matched)
 190         return Prefix.size() + StringRef(I->Name).size();
 191     }
 192   }
 193   return 0;
 194 }
 195
 196 // Returns true if one of the Prefixes + In.Names matches Option
 197 static bool optionMatches(const OptTable::Info &In, StringRef Option) {
 198   if (In.Prefixes)
 199     for (size_t I = 0; In.Prefixes[I]; I++)
 200       if (Option == std::string(In.Prefixes[I]) + In.Name)
 201         return true;
 202   return false;
 203 }
 204
 205 // This function is for flag value completion.
 206 // Eg. When "-stdlib=" and "l" was passed to this function, it will return
 207 // appropiriate values for stdlib, which starts with l.
 208 std::vector<std::string>
 209 OptTable::suggestValueCompletions(StringRef Option, StringRef Arg) const {
 210   // Search all options and return possible values.
 211   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 212     const Info &In = OptionInfos[I];
 213     if (!In.Values || !optionMatches(In, Option))
 214       continue;
 215
 216     SmallVector<StringRef, 8> Candidates;
 217     StringRef(In.Values).split(Candidates, ",", -1, false);
 218
 219     std::vector<std::string> Result;
 220     for (StringRef Val : Candidates)
 221       if (Val.startswith(Arg) && Arg.compare(Val))
 222         Result.push_back(Val);
 223     return Result;
 224   }
 225   return {};
 226 }
 227
 228 std::vector<std::string>
 229 OptTable::findByPrefix(StringRef Cur, unsigned short DisableFlags) const {
 230   std::vector<std::string> Ret;
 231   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 232     const Info &In = OptionInfos[I];
 233     if (!In.Prefixes || (!In.HelpText && !In.GroupID))
 234       continue;
 235     if (In.Flags & DisableFlags)
 236       continue;
 237
 238     for (int I = 0; In.Prefixes[I]; I++) {
 239       std::string S = std::string(In.Prefixes[I]) + std::string(In.Name) + "\t";
 240       if (In.HelpText)
 241         S += In.HelpText;
 242       if (StringRef(S).startswith(Cur) && S.compare(std::string(Cur) + "\t"))
 243         Ret.push_back(S);
 244     }
 245   }
 246   return Ret;
 247 }
 248
 249 unsigned OptTable::findNearest(StringRef Option, std::string &NearestString,
 250                                unsigned FlagsToInclude, unsigned FlagsToExclude,
 251                                unsigned MinimumLength) const {
 252   assert(!Option.empty());
 253
 254   // Consider each [option prefix + option name] pair as a candidate, finding
 255   // 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     // We can eliminate some option prefix/name pairs as candidates right away:
 262     // * Ignore option candidates with empty names, such as "--", or names
 263     //   that do not meet the minimum length.
 264     if (CandidateName.empty() || CandidateName.size() < MinimumLength)
 265       continue;
 266
 267     // * If FlagsToInclude were specified, ignore options that don't include
 268     //   those flags.
 269     if (FlagsToInclude && !(CandidateInfo.Flags & FlagsToInclude))
 270       continue;
 271     // * Ignore options that contain the FlagsToExclude.
 272     if (CandidateInfo.Flags & FlagsToExclude)
 273       continue;
 274
 275     // * Ignore positional argument option candidates (which do not
 276     //   have prefixes).
 277     if (!CandidateInfo.Prefixes)
 278       continue;
 279
 280     // Now check if the candidate ends with a character commonly used when
 281     // delimiting an option from its value, such as '=' or ':'. If it does,
 282     // attempt to split the given option based on that delimiter.
 283     StringRef LHS, RHS;
 284     char Last = CandidateName.back();
 285     bool CandidateHasDelimiter = Last == '=' || Last == ':';
 286     std::string NormalizedName = Option;
 287     if (CandidateHasDelimiter) {
 288       std::tie(LHS, RHS) = Option.split(Last);
 289       NormalizedName = LHS;
 290       if (Option.find(Last) == LHS.size())
 291         NormalizedName += Last;
 292     }
 293
 294     // Consider each possible prefix for each candidate to find the most
 295     // appropriate one. For example, if a user asks for "--helm", suggest
 296     // "--help" over "-help".
 297     for (int P = 0;
 298          const char *const CandidatePrefix = CandidateInfo.Prefixes[P]; P++) {
 299       std::string Candidate = (CandidatePrefix + CandidateName).str();
 300       StringRef CandidateRef = Candidate;
 301       unsigned Distance =
 302           CandidateRef.edit_distance(NormalizedName, /*AllowReplacements=*/true,
 303                                      /*MaxEditDistance=*/BestDistance);
 304       if (RHS.empty() && CandidateHasDelimiter) {
 305         // The Candidate ends with a = or : delimiter, but the option passed in
 306         // didn't contain the delimiter (or doesn't have anything after it).
 307         // In that case, penalize the correction: `-nodefaultlibs` is more
 308         // likely to be a spello for `-nodefaultlib` than `-nodefaultlib:` even
 309         // though both have an unmodified editing distance of 1, since the
 310         // latter would need an argument.
 311         ++Distance;
 312       }
 313       if (Distance < BestDistance) {
 314         BestDistance = Distance;
 315         NearestString = (Candidate + RHS).str();
 316       }
 317     }
 318   }
 319   return BestDistance;
 320 }
 321
 322 bool OptTable::addValues(const char *Option, const char *Values) {
 323   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 324     Info &In = OptionInfos[I];
 325     if (optionMatches(In, Option)) {
 326       In.Values = Values;
 327       return true;
 328     }
 329   }
 330   return false;
 331 }
 332
 333 Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
 334                            unsigned FlagsToInclude,
 335                            unsigned FlagsToExclude) const {
 336   unsigned Prev = Index;
 337   const char *Str = Args.getArgString(Index);
 338
 339   // Anything that doesn't start with PrefixesUnion is an input, as is '-'
 340   // itself.
 341   if (isInput(PrefixesUnion, Str))
 342     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 343
 344   const Info *Start = OptionInfos.data() + FirstSearchableIndex;
 345   const Info *End = OptionInfos.data() + OptionInfos.size();
 346   StringRef Name = StringRef(Str).ltrim(PrefixChars);
 347
 348   // Search for the first next option which could be a prefix.
 349   Start = std::lower_bound(Start, End, Name.data());
 350
 351   // Options are stored in sorted order, with '\0' at the end of the
 352   // alphabet. Since the only options which can accept a string must
 353   // prefix it, we iteratively search for the next option which could
 354   // be a prefix.
 355   //
 356   // FIXME: This is searching much more than necessary, but I am
 357   // blanking on the simplest way to make it fast. We can solve this
 358   // problem when we move to TableGen.
 359   for (; Start != End; ++Start) {
 360     unsigned ArgSize = 0;
 361     // Scan for first option which is a proper prefix.
 362     for (; Start != End; ++Start)
 363       if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
 364         break;
 365     if (Start == End)
 366       break;
 367
 368     Option Opt(Start, this);
 369
 370     if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
 371       continue;
 372     if (Opt.hasFlag(FlagsToExclude))
 373       continue;
 374
 375     // See if this option matches.
 376     if (Arg *A = Opt.accept(Args, Index, ArgSize))
 377       return A;
 378
 379     // Otherwise, see if this argument was missing values.
 380     if (Prev != Index)
 381       return nullptr;
 382   }
 383
 384   // If we failed to find an option and this arg started with /, then it's
 385   // probably an input path.
 386   if (Str[0] == '/')
 387     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 388
 389   return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
 390 }
 391
 392 InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
 393                                  unsigned &MissingArgIndex,
 394                                  unsigned &MissingArgCount,
 395                                  unsigned FlagsToInclude,
 396                                  unsigned FlagsToExclude) const {
 397   InputArgList Args(ArgArr.begin(), ArgArr.end());
 398
 399   // FIXME: Handle '@' args (or at least error on them).
 400
 401   MissingArgIndex = MissingArgCount = 0;
 402   unsigned Index = 0, End = ArgArr.size();
 403   while (Index < End) {
 404     // Ingore nullptrs, they are response file's EOL markers
 405     if (Args.getArgString(Index) == nullptr) {
 406       ++Index;
 407       continue;
 408     }
 409     // Ignore empty arguments (other things may still take them as arguments).
 410     StringRef Str = Args.getArgString(Index);
 411     if (Str == "") {
 412       ++Index;
 413       continue;
 414     }
 415
 416     unsigned Prev = Index;
 417     Arg *A = ParseOneArg(Args, Index, FlagsToInclude, FlagsToExclude);
 418     assert(Index > Prev && "Parser failed to consume argument.");
 419
 420     // Check for missing argument error.
 421     if (!A) {
 422       assert(Index >= End && "Unexpected parser error.");
 423       assert(Index - Prev - 1 && "No missing arguments!");
 424       MissingArgIndex = Prev;
 425       MissingArgCount = Index - Prev - 1;
 426       break;
 427     }
 428
 429     Args.append(A);
 430   }
 431
 432   return Args;
 433 }
 434
 435 static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
 436   const Option O = Opts.getOption(Id);
 437   std::string Name = O.getPrefixedName();
 438
 439   // Add metavar, if used.
 440   switch (O.getKind()) {
 441   case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
 442     llvm_unreachable("Invalid option with help text.");
 443
 444   case Option::MultiArgClass:
 445     if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
 446       // For MultiArgs, metavar is full list of all argument names.
 447       Name += ' ';
 448       Name += MetaVarName;
 449     }
 450     else {
 451       // For MultiArgs<N>, if metavar not supplied, print <value> N times.
 452       for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
 453         Name += " <value>";
 454       }
 455     }
 456     break;
 457
 458   case Option::FlagClass:
 459     break;
 460
 461   case Option::ValuesClass:
 462     break;
 463
 464   case Option::SeparateClass: case Option::JoinedOrSeparateClass:
 465   case Option::RemainingArgsClass: case Option::RemainingArgsJoinedClass:
 466     Name += ' ';
 467     LLVM_FALLTHROUGH;
 468   case Option::JoinedClass: case Option::CommaJoinedClass:
 469   case Option::JoinedAndSeparateClass:
 470     if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
 471       Name += MetaVarName;
 472     else
 473       Name += "<value>";
 474     break;
 475   }
 476
 477   return Name;
 478 }
 479
 480 namespace {
 481 struct OptionInfo {
 482   std::string Name;
 483   StringRef HelpText;
 484 };
 485 } // namespace
 486
 487 static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
 488                                 std::vector<OptionInfo> &OptionHelp) {
 489   OS << Title << ":\n";
 490
 491   // Find the maximum option length.
 492   unsigned OptionFieldWidth = 0;
 493   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
 494     // Limit the amount of padding we are willing to give up for alignment.
 495     unsigned Length = OptionHelp[i].Name.size();
 496     if (Length <= 23)
 497       OptionFieldWidth = std::max(OptionFieldWidth, Length);
 498   }
 499
 500   const unsigned InitialPad = 2;
 501   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
 502     const std::string &Option = OptionHelp[i].Name;
 503     int Pad = OptionFieldWidth - int(Option.size());
 504     OS.indent(InitialPad) << Option;
 505
 506     // Break on long option names.
 507     if (Pad < 0) {
 508       OS << "\n";
 509       Pad = OptionFieldWidth + InitialPad;
 510     }
 511     OS.indent(Pad + 1) << OptionHelp[i].HelpText << '\n';
 512   }
 513 }
 514
 515 static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
 516   unsigned GroupID = Opts.getOptionGroupID(Id);
 517
 518   // If not in a group, return the default help group.
 519   if (!GroupID)
 520     return "OPTIONS";
 521
 522   // Abuse the help text of the option groups to store the "help group"
 523   // name.
 524   //
 525   // FIXME: Split out option groups.
 526   if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
 527     return GroupHelp;
 528
 529   // Otherwise keep looking.
 530   return getOptionHelpGroup(Opts, GroupID);
 531 }
 532
 533 void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
 534                          bool ShowHidden, bool ShowAllAliases) const {
 535   PrintHelp(OS, Usage, Title, /*Include*/ 0, /*Exclude*/
 536             (ShowHidden ? 0 : HelpHidden), ShowAllAliases);
 537 }
 538
 539 void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
 540                          unsigned FlagsToInclude, unsigned FlagsToExclude,
 541                          bool ShowAllAliases) const {
 542   OS << "OVERVIEW: " << Title << "\n\n";
 543   OS << "USAGE: " << Usage << "\n\n";
 544
 545   // Render help text into a map of group-name to a list of (option, help)
 546   // pairs.
 547   std::map<std::string, std::vector<OptionInfo>> GroupedOptionHelp;
 548
 549   for (unsigned Id = 1, e = getNumOptions() + 1; Id != e; ++Id) {
 550     // FIXME: Split out option groups.
 551     if (getOptionKind(Id) == Option::GroupClass)
 552       continue;
 553
 554     unsigned Flags = getInfo(Id).Flags;
 555     if (FlagsToInclude && !(Flags & FlagsToInclude))
 556       continue;
 557     if (Flags & FlagsToExclude)
 558       continue;
 559
 560     // If an alias doesn't have a help text, show a help text for the aliased
 561     // option instead.
 562     const char *HelpText = getOptionHelpText(Id);
 563     if (!HelpText && ShowAllAliases) {
 564       const Option Alias = getOption(Id).getAlias();
 565       if (Alias.isValid())
 566         HelpText = getOptionHelpText(Alias.getID());
 567     }
 568
 569     if (HelpText) {
 570       const char *HelpGroup = getOptionHelpGroup(*this, Id);
 571       const std::string &OptName = getOptionHelpName(*this, Id);
 572       GroupedOptionHelp[HelpGroup].push_back({OptName, HelpText});
 573     }
 574   }
 575
 576   for (auto& OptionGroup : GroupedOptionHelp) {
 577     if (OptionGroup.first != GroupedOptionHelp.begin()->first)
 578       OS << "\n";
 579     PrintHelpOptionList(OS, OptionGroup.first, OptionGroup.second);
 580   }
 581
 582   OS.flush();
 583 }