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 as a candidate, finding the closest match.
 255   unsigned BestDistance = UINT_MAX;
 256   for (const Info &CandidateInfo :
 257        ArrayRef<Info>(OptionInfos).drop_front(FirstSearchableIndex)) {
 258     StringRef CandidateName = CandidateInfo.Name;
 259
 260     // Ignore option candidates with empty names, such as "--", or names
 261     // that do not meet the minimum length.
 262     if (CandidateName.empty() || CandidateName.size() < MinimumLength)
 263       continue;
 264
 265     // If FlagsToInclude were specified, ignore options that don't include
 266     // those flags.
 267     if (FlagsToInclude && !(CandidateInfo.Flags & FlagsToInclude))
 268       continue;
 269     // Ignore options that contain the FlagsToExclude.
 270     if (CandidateInfo.Flags & FlagsToExclude)
 271       continue;
 272
 273     // Ignore positional argument option candidates (which do not
 274     // have prefixes).
 275     if (!CandidateInfo.Prefixes)
 276       continue;
 277     // Find the most appropriate prefix. For example, if a user asks for
 278     // "--helm", suggest "--help" over "-help".
 279     StringRef Prefix = CandidateInfo.Prefixes[0];
 280     for (int P = 1; CandidateInfo.Prefixes[P]; P++) {
 281       if (Option.startswith(CandidateInfo.Prefixes[P]))
 282         Prefix = CandidateInfo.Prefixes[P];
 283     }
 284
 285     // Check if the candidate ends with a character commonly used when
 286     // delimiting an option from its value, such as '=' or ':'. If it does,
 287     // attempt to split the given option based on that delimiter.
 288     std::string Delimiter = "";
 289     char Last = CandidateName.back();
 290     if (Last == '=' || Last == ':')
 291       Delimiter = std::string(1, Last);
 292
 293     StringRef LHS, RHS;
 294     if (Delimiter.empty())
 295       LHS = Option;
 296     else
 297       std::tie(LHS, RHS) = Option.split(Last);
 298
 299     std::string NormalizedName =
 300         (LHS.drop_front(Prefix.size()) + Delimiter).str();
 301     unsigned Distance =
 302         CandidateName.edit_distance(NormalizedName, /*AllowReplacements=*/true,
 303                                     /*MaxEditDistance=*/BestDistance);
 304     if (Distance < BestDistance) {
 305       BestDistance = Distance;
 306       NearestString = (Prefix + CandidateName + RHS).str();
 307     }
 308   }
 309   return BestDistance;
 310 }
 311
 312 bool OptTable::addValues(const char *Option, const char *Values) {
 313   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
 314     Info &In = OptionInfos[I];
 315     if (optionMatches(In, Option)) {
 316       In.Values = Values;
 317       return true;
 318     }
 319   }
 320   return false;
 321 }
 322
 323 Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
 324                            unsigned FlagsToInclude,
 325                            unsigned FlagsToExclude) const {
 326   unsigned Prev = Index;
 327   const char *Str = Args.getArgString(Index);
 328
 329   // Anything that doesn't start with PrefixesUnion is an input, as is '-'
 330   // itself.
 331   if (isInput(PrefixesUnion, Str))
 332     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 333
 334   const Info *Start = OptionInfos.data() + FirstSearchableIndex;
 335   const Info *End = OptionInfos.data() + OptionInfos.size();
 336   StringRef Name = StringRef(Str).ltrim(PrefixChars);
 337
 338   // Search for the first next option which could be a prefix.
 339   Start = std::lower_bound(Start, End, Name.data());
 340
 341   // Options are stored in sorted order, with '\0' at the end of the
 342   // alphabet. Since the only options which can accept a string must
 343   // prefix it, we iteratively search for the next option which could
 344   // be a prefix.
 345   //
 346   // FIXME: This is searching much more than necessary, but I am
 347   // blanking on the simplest way to make it fast. We can solve this
 348   // problem when we move to TableGen.
 349   for (; Start != End; ++Start) {
 350     unsigned ArgSize = 0;
 351     // Scan for first option which is a proper prefix.
 352     for (; Start != End; ++Start)
 353       if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
 354         break;
 355     if (Start == End)
 356       break;
 357
 358     Option Opt(Start, this);
 359
 360     if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
 361       continue;
 362     if (Opt.hasFlag(FlagsToExclude))
 363       continue;
 364
 365     // See if this option matches.
 366     if (Arg *A = Opt.accept(Args, Index, ArgSize))
 367       return A;
 368
 369     // Otherwise, see if this argument was missing values.
 370     if (Prev != Index)
 371       return nullptr;
 372   }
 373
 374   // If we failed to find an option and this arg started with /, then it's
 375   // probably an input path.
 376   if (Str[0] == '/')
 377     return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
 378
 379   return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
 380 }
 381
 382 InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
 383                                  unsigned &MissingArgIndex,
 384                                  unsigned &MissingArgCount,
 385                                  unsigned FlagsToInclude,
 386                                  unsigned FlagsToExclude) const {
 387   InputArgList Args(ArgArr.begin(), ArgArr.end());
 388
 389   // FIXME: Handle '@' args (or at least error on them).
 390
 391   MissingArgIndex = MissingArgCount = 0;
 392   unsigned Index = 0, End = ArgArr.size();
 393   while (Index < End) {
 394     // Ingore nullptrs, they are response file's EOL markers
 395     if (Args.getArgString(Index) == nullptr) {
 396       ++Index;
 397       continue;
 398     }
 399     // Ignore empty arguments (other things may still take them as arguments).
 400     StringRef Str = Args.getArgString(Index);
 401     if (Str == "") {
 402       ++Index;
 403       continue;
 404     }
 405
 406     unsigned Prev = Index;
 407     Arg *A = ParseOneArg(Args, Index, FlagsToInclude, FlagsToExclude);
 408     assert(Index > Prev && "Parser failed to consume argument.");
 409
 410     // Check for missing argument error.
 411     if (!A) {
 412       assert(Index >= End && "Unexpected parser error.");
 413       assert(Index - Prev - 1 && "No missing arguments!");
 414       MissingArgIndex = Prev;
 415       MissingArgCount = Index - Prev - 1;
 416       break;
 417     }
 418
 419     Args.append(A);
 420   }
 421
 422   return Args;
 423 }
 424
 425 static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
 426   const Option O = Opts.getOption(Id);
 427   std::string Name = O.getPrefixedName();
 428
 429   // Add metavar, if used.
 430   switch (O.getKind()) {
 431   case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
 432     llvm_unreachable("Invalid option with help text.");
 433
 434   case Option::MultiArgClass:
 435     if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
 436       // For MultiArgs, metavar is full list of all argument names.
 437       Name += ' ';
 438       Name += MetaVarName;
 439     }
 440     else {
 441       // For MultiArgs<N>, if metavar not supplied, print <value> N times.
 442       for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
 443         Name += " <value>";
 444       }
 445     }
 446     break;
 447
 448   case Option::FlagClass:
 449     break;
 450
 451   case Option::ValuesClass:
 452     break;
 453
 454   case Option::SeparateClass: case Option::JoinedOrSeparateClass:
 455   case Option::RemainingArgsClass: case Option::RemainingArgsJoinedClass:
 456     Name += ' ';
 457     LLVM_FALLTHROUGH;
 458   case Option::JoinedClass: case Option::CommaJoinedClass:
 459   case Option::JoinedAndSeparateClass:
 460     if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
 461       Name += MetaVarName;
 462     else
 463       Name += "<value>";
 464     break;
 465   }
 466
 467   return Name;
 468 }
 469
 470 namespace {
 471 struct OptionInfo {
 472   std::string Name;
 473   StringRef HelpText;
 474 };
 475 } // namespace
 476
 477 static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
 478                                 std::vector<OptionInfo> &OptionHelp) {
 479   OS << Title << ":\n";
 480
 481   // Find the maximum option length.
 482   unsigned OptionFieldWidth = 0;
 483   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
 484     // Limit the amount of padding we are willing to give up for alignment.
 485     unsigned Length = OptionHelp[i].Name.size();
 486     if (Length <= 23)
 487       OptionFieldWidth = std::max(OptionFieldWidth, Length);
 488   }
 489
 490   const unsigned InitialPad = 2;
 491   for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
 492     const std::string &Option = OptionHelp[i].Name;
 493     int Pad = OptionFieldWidth - int(Option.size());
 494     OS.indent(InitialPad) << Option;
 495
 496     // Break on long option names.
 497     if (Pad < 0) {
 498       OS << "\n";
 499       Pad = OptionFieldWidth + InitialPad;
 500     }
 501     OS.indent(Pad + 1) << OptionHelp[i].HelpText << '\n';
 502   }
 503 }
 504
 505 static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
 506   unsigned GroupID = Opts.getOptionGroupID(Id);
 507
 508   // If not in a group, return the default help group.
 509   if (!GroupID)
 510     return "OPTIONS";
 511
 512   // Abuse the help text of the option groups to store the "help group"
 513   // name.
 514   //
 515   // FIXME: Split out option groups.
 516   if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
 517     return GroupHelp;
 518
 519   // Otherwise keep looking.
 520   return getOptionHelpGroup(Opts, GroupID);
 521 }
 522
 523 void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
 524                          bool ShowHidden, bool ShowAllAliases) const {
 525   PrintHelp(OS, Usage, Title, /*Include*/ 0, /*Exclude*/
 526             (ShowHidden ? 0 : HelpHidden), ShowAllAliases);
 527 }
 528
 529 void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
 530                          unsigned FlagsToInclude, unsigned FlagsToExclude,
 531                          bool ShowAllAliases) const {
 532   OS << "OVERVIEW: " << Title << "\n\n";
 533   OS << "USAGE: " << Usage << "\n\n";
 534
 535   // Render help text into a map of group-name to a list of (option, help)
 536   // pairs.
 537   std::map<std::string, std::vector<OptionInfo>> GroupedOptionHelp;
 538
 539   for (unsigned Id = 1, e = getNumOptions() + 1; Id != e; ++Id) {
 540     // FIXME: Split out option groups.
 541     if (getOptionKind(Id) == Option::GroupClass)
 542       continue;
 543
 544     unsigned Flags = getInfo(Id).Flags;
 545     if (FlagsToInclude && !(Flags & FlagsToInclude))
 546       continue;
 547     if (Flags & FlagsToExclude)
 548       continue;
 549
 550     // If an alias doesn't have a help text, show a help text for the aliased
 551     // option instead.
 552     const char *HelpText = getOptionHelpText(Id);
 553     if (!HelpText && ShowAllAliases) {
 554       const Option Alias = getOption(Id).getAlias();
 555       if (Alias.isValid())
 556         HelpText = getOptionHelpText(Alias.getID());
 557     }
 558
 559     if (HelpText) {
 560       const char *HelpGroup = getOptionHelpGroup(*this, Id);
 561       const std::string &OptName = getOptionHelpName(*this, Id);
 562       GroupedOptionHelp[HelpGroup].push_back({OptName, HelpText});
 563     }
 564   }
 565
 566   for (auto& OptionGroup : GroupedOptionHelp) {
 567     if (OptionGroup.first != GroupedOptionHelp.begin()->first)
 568       OS << "\n";
 569     PrintHelpOptionList(OS, OptionGroup.first, OptionGroup.second);
 570   }
 571
 572   OS.flush();
 573 }