OptTable.cpp revision 344779 
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
30using namespace llvm;
31using namespace llvm::opt;
32
33namespace llvm {
34namespace 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).
39static 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
60static 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
66static 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.
89static 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
96OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
97
98OptTable::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
160OptTable::~OptTable() = default;
161
162const 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
170static 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.
181static 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
198static 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.
209std::vector<std::string>
210OptTable::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
229std::vector<std::string>
230OptTable::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
250unsigned 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
313bool 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
324Arg *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
383InputArgList 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
426static 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
471namespace {
472struct OptionInfo {
473  std::string Name;
474  StringRef HelpText;
475};
476} // namespace
477
478static 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
506static 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
524void 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
530void 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}
575