OptTable.cpp revision 280031 
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
20using namespace llvm;
21using namespace llvm::opt;
22
23namespace llvm {
24namespace 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).
29static 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
50static 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
56static 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.
79static inline bool operator<(const OptTable::Info &I, const char *Name) {
80  return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
81}
82}
83}
84
85OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
86
87OptTable::OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos,
88                   bool _IgnoreCase)
89  : OptionInfos(_OptionInfos),
90    NumOptionInfos(_NumOptionInfos),
91    IgnoreCase(_IgnoreCase),
92    TheInputOptionID(0),
93    TheUnknownOptionID(0),
94    FirstSearchableIndex(0)
95{
96  // Explicitly zero initialize the error to work around a bug in array
97  // value-initialization on MinGW with gcc 4.3.5.
98
99  // Find start of normal options.
100  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
101    unsigned Kind = getInfo(i + 1).Kind;
102    if (Kind == Option::InputClass) {
103      assert(!TheInputOptionID && "Cannot have multiple input options!");
104      TheInputOptionID = getInfo(i + 1).ID;
105    } else if (Kind == Option::UnknownClass) {
106      assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
107      TheUnknownOptionID = getInfo(i + 1).ID;
108    } else if (Kind != Option::GroupClass) {
109      FirstSearchableIndex = i;
110      break;
111    }
112  }
113  assert(FirstSearchableIndex != 0 && "No searchable options?");
114
115#ifndef NDEBUG
116  // Check that everything after the first searchable option is a
117  // regular option class.
118  for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
119    Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
120    assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
121            Kind != Option::GroupClass) &&
122           "Special options should be defined first!");
123  }
124
125  // Check that options are in order.
126  for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
127    if (!(getInfo(i) < getInfo(i + 1))) {
128      getOption(i).dump();
129      getOption(i + 1).dump();
130      llvm_unreachable("Options are not in order!");
131    }
132  }
133#endif
134
135  // Build prefixes.
136  for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
137                i != e; ++i) {
138    if (const char *const *P = getInfo(i).Prefixes) {
139      for (; *P != nullptr; ++P) {
140        PrefixesUnion.insert(*P);
141      }
142    }
143  }
144
145  // Build prefix chars.
146  for (llvm::StringSet<>::const_iterator I = PrefixesUnion.begin(),
147                                         E = PrefixesUnion.end(); I != E; ++I) {
148    StringRef Prefix = I->getKey();
149    for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
150                                   C != CE; ++C)
151      if (std::find(PrefixChars.begin(), PrefixChars.end(), *C)
152            == PrefixChars.end())
153        PrefixChars.push_back(*C);
154  }
155}
156
157OptTable::~OptTable() {
158}
159
160const Option OptTable::getOption(OptSpecifier Opt) const {
161  unsigned id = Opt.getID();
162  if (id == 0)
163    return Option(nullptr, nullptr);
164  assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
165  return Option(&getInfo(id), this);
166}
167
168static bool isInput(const llvm::StringSet<> &Prefixes, StringRef Arg) {
169  if (Arg == "-")
170    return true;
171  for (llvm::StringSet<>::const_iterator I = Prefixes.begin(),
172                                         E = Prefixes.end(); I != E; ++I)
173    if (Arg.startswith(I->getKey()))
174      return false;
175  return true;
176}
177
178/// \returns Matched size. 0 means no match.
179static unsigned matchOption(const OptTable::Info *I, StringRef Str,
180                            bool IgnoreCase) {
181  for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
182    StringRef Prefix(*Pre);
183    if (Str.startswith(Prefix)) {
184      StringRef Rest = Str.substr(Prefix.size());
185      bool Matched = IgnoreCase
186          ? Rest.startswith_lower(I->Name)
187          : Rest.startswith(I->Name);
188      if (Matched)
189        return Prefix.size() + StringRef(I->Name).size();
190    }
191  }
192  return 0;
193}
194
195Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
196                           unsigned FlagsToInclude,
197                           unsigned FlagsToExclude) const {
198  unsigned Prev = Index;
199  const char *Str = Args.getArgString(Index);
200
201  // Anything that doesn't start with PrefixesUnion is an input, as is '-'
202  // itself.
203  if (isInput(PrefixesUnion, Str))
204    return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
205
206  const Info *Start = OptionInfos + FirstSearchableIndex;
207  const Info *End = OptionInfos + getNumOptions();
208  StringRef Name = StringRef(Str).ltrim(PrefixChars);
209
210  // Search for the first next option which could be a prefix.
211  Start = std::lower_bound(Start, End, Name.data());
212
213  // Options are stored in sorted order, with '\0' at the end of the
214  // alphabet. Since the only options which can accept a string must
215  // prefix it, we iteratively search for the next option which could
216  // be a prefix.
217  //
218  // FIXME: This is searching much more than necessary, but I am
219  // blanking on the simplest way to make it fast. We can solve this
220  // problem when we move to TableGen.
221  for (; Start != End; ++Start) {
222    unsigned ArgSize = 0;
223    // Scan for first option which is a proper prefix.
224    for (; Start != End; ++Start)
225      if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
226        break;
227    if (Start == End)
228      break;
229
230    Option Opt(Start, this);
231
232    if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
233      continue;
234    if (Opt.hasFlag(FlagsToExclude))
235      continue;
236
237    // See if this option matches.
238    if (Arg *A = Opt.accept(Args, Index, ArgSize))
239      return A;
240
241    // Otherwise, see if this argument was missing values.
242    if (Prev != Index)
243      return nullptr;
244  }
245
246  // If we failed to find an option and this arg started with /, then it's
247  // probably an input path.
248  if (Str[0] == '/')
249    return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
250
251  return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
252}
253
254InputArgList *OptTable::ParseArgs(const char *const *ArgBegin,
255                                  const char *const *ArgEnd,
256                                  unsigned &MissingArgIndex,
257                                  unsigned &MissingArgCount,
258                                  unsigned FlagsToInclude,
259                                  unsigned FlagsToExclude) const {
260  InputArgList *Args = new InputArgList(ArgBegin, ArgEnd);
261
262  // FIXME: Handle '@' args (or at least error on them).
263
264  MissingArgIndex = MissingArgCount = 0;
265  unsigned Index = 0, End = ArgEnd - ArgBegin;
266  while (Index < End) {
267    // Ingore nullptrs, they are response file's EOL markers
268    if (Args->getArgString(Index) == nullptr) {
269      ++Index;
270      continue;
271    }
272    // Ignore empty arguments (other things may still take them as arguments).
273    StringRef Str = Args->getArgString(Index);
274    if (Str == "") {
275      ++Index;
276      continue;
277    }
278
279    unsigned Prev = Index;
280    Arg *A = ParseOneArg(*Args, Index, FlagsToInclude, FlagsToExclude);
281    assert(Index > Prev && "Parser failed to consume argument.");
282
283    // Check for missing argument error.
284    if (!A) {
285      assert(Index >= End && "Unexpected parser error.");
286      assert(Index - Prev - 1 && "No missing arguments!");
287      MissingArgIndex = Prev;
288      MissingArgCount = Index - Prev - 1;
289      break;
290    }
291
292    Args->append(A);
293  }
294
295  return Args;
296}
297
298static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
299  const Option O = Opts.getOption(Id);
300  std::string Name = O.getPrefixedName();
301
302  // Add metavar, if used.
303  switch (O.getKind()) {
304  case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
305    llvm_unreachable("Invalid option with help text.");
306
307  case Option::MultiArgClass:
308    if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
309      // For MultiArgs, metavar is full list of all argument names.
310      Name += ' ';
311      Name += MetaVarName;
312    }
313    else {
314      // For MultiArgs<N>, if metavar not supplied, print <value> N times.
315      for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
316        Name += " <value>";
317      }
318    }
319    break;
320
321  case Option::FlagClass:
322    break;
323
324  case Option::SeparateClass: case Option::JoinedOrSeparateClass:
325  case Option::RemainingArgsClass:
326    Name += ' ';
327    // FALLTHROUGH
328  case Option::JoinedClass: case Option::CommaJoinedClass:
329  case Option::JoinedAndSeparateClass:
330    if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
331      Name += MetaVarName;
332    else
333      Name += "<value>";
334    break;
335  }
336
337  return Name;
338}
339
340static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
341                                std::vector<std::pair<std::string,
342                                const char*> > &OptionHelp) {
343  OS << Title << ":\n";
344
345  // Find the maximum option length.
346  unsigned OptionFieldWidth = 0;
347  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
348    // Skip titles.
349    if (!OptionHelp[i].second)
350      continue;
351
352    // Limit the amount of padding we are willing to give up for alignment.
353    unsigned Length = OptionHelp[i].first.size();
354    if (Length <= 23)
355      OptionFieldWidth = std::max(OptionFieldWidth, Length);
356  }
357
358  const unsigned InitialPad = 2;
359  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
360    const std::string &Option = OptionHelp[i].first;
361    int Pad = OptionFieldWidth - int(Option.size());
362    OS.indent(InitialPad) << Option;
363
364    // Break on long option names.
365    if (Pad < 0) {
366      OS << "\n";
367      Pad = OptionFieldWidth + InitialPad;
368    }
369    OS.indent(Pad + 1) << OptionHelp[i].second << '\n';
370  }
371}
372
373static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
374  unsigned GroupID = Opts.getOptionGroupID(Id);
375
376  // If not in a group, return the default help group.
377  if (!GroupID)
378    return "OPTIONS";
379
380  // Abuse the help text of the option groups to store the "help group"
381  // name.
382  //
383  // FIXME: Split out option groups.
384  if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
385    return GroupHelp;
386
387  // Otherwise keep looking.
388  return getOptionHelpGroup(Opts, GroupID);
389}
390
391void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
392                         bool ShowHidden) const {
393  PrintHelp(OS, Name, Title, /*Include*/ 0, /*Exclude*/
394            (ShowHidden ? 0 : HelpHidden));
395}
396
397
398void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
399                         unsigned FlagsToInclude,
400                         unsigned FlagsToExclude) const {
401  OS << "OVERVIEW: " << Title << "\n";
402  OS << '\n';
403  OS << "USAGE: " << Name << " [options] <inputs>\n";
404  OS << '\n';
405
406  // Render help text into a map of group-name to a list of (option, help)
407  // pairs.
408  typedef std::map<std::string,
409                 std::vector<std::pair<std::string, const char*> > > helpmap_ty;
410  helpmap_ty GroupedOptionHelp;
411
412  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
413    unsigned Id = i + 1;
414
415    // FIXME: Split out option groups.
416    if (getOptionKind(Id) == Option::GroupClass)
417      continue;
418
419    unsigned Flags = getInfo(Id).Flags;
420    if (FlagsToInclude && !(Flags & FlagsToInclude))
421      continue;
422    if (Flags & FlagsToExclude)
423      continue;
424
425    if (const char *Text = getOptionHelpText(Id)) {
426      const char *HelpGroup = getOptionHelpGroup(*this, Id);
427      const std::string &OptName = getOptionHelpName(*this, Id);
428      GroupedOptionHelp[HelpGroup].push_back(std::make_pair(OptName, Text));
429    }
430  }
431
432  for (helpmap_ty::iterator it = GroupedOptionHelp .begin(),
433         ie = GroupedOptionHelp.end(); it != ie; ++it) {
434    if (it != GroupedOptionHelp .begin())
435      OS << "\n";
436    PrintHelpOptionList(OS, it->first, it->second);
437  }
438
439  OS.flush();
440}
441