OptTable.cpp revision 314564 
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/ADT/STLExtras.h"
12#include "llvm/Option/Arg.h"
13#include "llvm/Option/ArgList.h"
14#include "llvm/Option/Option.h"
15#include "llvm/Support/ErrorHandling.h"
16#include "llvm/Support/raw_ostream.h"
17#include <algorithm>
18#include <cctype>
19#include <map>
20
21using namespace llvm;
22using namespace llvm::opt;
23
24namespace llvm {
25namespace opt {
26
27// Ordering on Info. The ordering is *almost* case-insensitive lexicographic,
28// with an exceptions. '\0' comes at the end of the alphabet instead of the
29// beginning (thus options precede any other options which prefix them).
30static int StrCmpOptionNameIgnoreCase(const char *A, const char *B) {
31  const char *X = A, *Y = B;
32  char a = tolower(*A), b = tolower(*B);
33  while (a == b) {
34    if (a == '\0')
35      return 0;
36
37    a = tolower(*++X);
38    b = tolower(*++Y);
39  }
40
41  if (a == '\0') // A is a prefix of B.
42    return 1;
43  if (b == '\0') // B is a prefix of A.
44    return -1;
45
46  // Otherwise lexicographic.
47  return (a < b) ? -1 : 1;
48}
49
50#ifndef NDEBUG
51static int StrCmpOptionName(const char *A, const char *B) {
52  if (int N = StrCmpOptionNameIgnoreCase(A, B))
53    return N;
54  return strcmp(A, B);
55}
56
57static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
58  if (&A == &B)
59    return false;
60
61  if (int N = StrCmpOptionName(A.Name, B.Name))
62    return N < 0;
63
64  for (const char * const *APre = A.Prefixes,
65                  * const *BPre = B.Prefixes;
66                          *APre != nullptr && *BPre != nullptr; ++APre, ++BPre){
67    if (int N = StrCmpOptionName(*APre, *BPre))
68      return N < 0;
69  }
70
71  // Names are the same, check that classes are in order; exactly one
72  // should be joined, and it should succeed the other.
73  assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
74         "Unexpected classes for options with same name.");
75  return B.Kind == Option::JoinedClass;
76}
77#endif
78
79// Support lower_bound between info and an option name.
80static inline bool operator<(const OptTable::Info &I, const char *Name) {
81  return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
82}
83}
84}
85
86OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
87
88OptTable::OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase)
89    : OptionInfos(OptionInfos), IgnoreCase(IgnoreCase), TheInputOptionID(0),
90      TheUnknownOptionID(0), FirstSearchableIndex(0) {
91  // Explicitly zero initialize the error to work around a bug in array
92  // value-initialization on MinGW with gcc 4.3.5.
93
94  // Find start of normal options.
95  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
96    unsigned Kind = getInfo(i + 1).Kind;
97    if (Kind == Option::InputClass) {
98      assert(!TheInputOptionID && "Cannot have multiple input options!");
99      TheInputOptionID = getInfo(i + 1).ID;
100    } else if (Kind == Option::UnknownClass) {
101      assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
102      TheUnknownOptionID = getInfo(i + 1).ID;
103    } else if (Kind != Option::GroupClass) {
104      FirstSearchableIndex = i;
105      break;
106    }
107  }
108  assert(FirstSearchableIndex != 0 && "No searchable options?");
109
110#ifndef NDEBUG
111  // Check that everything after the first searchable option is a
112  // regular option class.
113  for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
114    Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
115    assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
116            Kind != Option::GroupClass) &&
117           "Special options should be defined first!");
118  }
119
120  // Check that options are in order.
121  for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
122    if (!(getInfo(i) < getInfo(i + 1))) {
123      getOption(i).dump();
124      getOption(i + 1).dump();
125      llvm_unreachable("Options are not in order!");
126    }
127  }
128#endif
129
130  // Build prefixes.
131  for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
132                i != e; ++i) {
133    if (const char *const *P = getInfo(i).Prefixes) {
134      for (; *P != nullptr; ++P) {
135        PrefixesUnion.insert(*P);
136      }
137    }
138  }
139
140  // Build prefix chars.
141  for (llvm::StringSet<>::const_iterator I = PrefixesUnion.begin(),
142                                         E = PrefixesUnion.end(); I != E; ++I) {
143    StringRef Prefix = I->getKey();
144    for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
145                                   C != CE; ++C)
146      if (!is_contained(PrefixChars, *C))
147        PrefixChars.push_back(*C);
148  }
149}
150
151OptTable::~OptTable() {
152}
153
154const Option OptTable::getOption(OptSpecifier Opt) const {
155  unsigned id = Opt.getID();
156  if (id == 0)
157    return Option(nullptr, nullptr);
158  assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
159  return Option(&getInfo(id), this);
160}
161
162static bool isInput(const llvm::StringSet<> &Prefixes, StringRef Arg) {
163  if (Arg == "-")
164    return true;
165  for (llvm::StringSet<>::const_iterator I = Prefixes.begin(),
166                                         E = Prefixes.end(); I != E; ++I)
167    if (Arg.startswith(I->getKey()))
168      return false;
169  return true;
170}
171
172/// \returns Matched size. 0 means no match.
173static unsigned matchOption(const OptTable::Info *I, StringRef Str,
174                            bool IgnoreCase) {
175  for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
176    StringRef Prefix(*Pre);
177    if (Str.startswith(Prefix)) {
178      StringRef Rest = Str.substr(Prefix.size());
179      bool Matched = IgnoreCase
180          ? Rest.startswith_lower(I->Name)
181          : Rest.startswith(I->Name);
182      if (Matched)
183        return Prefix.size() + StringRef(I->Name).size();
184    }
185  }
186  return 0;
187}
188
189Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
190                           unsigned FlagsToInclude,
191                           unsigned FlagsToExclude) const {
192  unsigned Prev = Index;
193  const char *Str = Args.getArgString(Index);
194
195  // Anything that doesn't start with PrefixesUnion is an input, as is '-'
196  // itself.
197  if (isInput(PrefixesUnion, Str))
198    return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
199
200  const Info *Start = OptionInfos.begin() + FirstSearchableIndex;
201  const Info *End = OptionInfos.end();
202  StringRef Name = StringRef(Str).ltrim(PrefixChars);
203
204  // Search for the first next option which could be a prefix.
205  Start = std::lower_bound(Start, End, Name.data());
206
207  // Options are stored in sorted order, with '\0' at the end of the
208  // alphabet. Since the only options which can accept a string must
209  // prefix it, we iteratively search for the next option which could
210  // be a prefix.
211  //
212  // FIXME: This is searching much more than necessary, but I am
213  // blanking on the simplest way to make it fast. We can solve this
214  // problem when we move to TableGen.
215  for (; Start != End; ++Start) {
216    unsigned ArgSize = 0;
217    // Scan for first option which is a proper prefix.
218    for (; Start != End; ++Start)
219      if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
220        break;
221    if (Start == End)
222      break;
223
224    Option Opt(Start, this);
225
226    if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
227      continue;
228    if (Opt.hasFlag(FlagsToExclude))
229      continue;
230
231    // See if this option matches.
232    if (Arg *A = Opt.accept(Args, Index, ArgSize))
233      return A;
234
235    // Otherwise, see if this argument was missing values.
236    if (Prev != Index)
237      return nullptr;
238  }
239
240  // If we failed to find an option and this arg started with /, then it's
241  // probably an input path.
242  if (Str[0] == '/')
243    return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
244
245  return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
246}
247
248InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
249                                 unsigned &MissingArgIndex,
250                                 unsigned &MissingArgCount,
251                                 unsigned FlagsToInclude,
252                                 unsigned FlagsToExclude) const {
253  InputArgList Args(ArgArr.begin(), ArgArr.end());
254
255  // FIXME: Handle '@' args (or at least error on them).
256
257  MissingArgIndex = MissingArgCount = 0;
258  unsigned Index = 0, End = ArgArr.size();
259  while (Index < End) {
260    // Ingore nullptrs, they are response file's EOL markers
261    if (Args.getArgString(Index) == nullptr) {
262      ++Index;
263      continue;
264    }
265    // Ignore empty arguments (other things may still take them as arguments).
266    StringRef Str = Args.getArgString(Index);
267    if (Str == "") {
268      ++Index;
269      continue;
270    }
271
272    unsigned Prev = Index;
273    Arg *A = ParseOneArg(Args, Index, FlagsToInclude, FlagsToExclude);
274    assert(Index > Prev && "Parser failed to consume argument.");
275
276    // Check for missing argument error.
277    if (!A) {
278      assert(Index >= End && "Unexpected parser error.");
279      assert(Index - Prev - 1 && "No missing arguments!");
280      MissingArgIndex = Prev;
281      MissingArgCount = Index - Prev - 1;
282      break;
283    }
284
285    Args.append(A);
286  }
287
288  return Args;
289}
290
291static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
292  const Option O = Opts.getOption(Id);
293  std::string Name = O.getPrefixedName();
294
295  // Add metavar, if used.
296  switch (O.getKind()) {
297  case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
298    llvm_unreachable("Invalid option with help text.");
299
300  case Option::MultiArgClass:
301    if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
302      // For MultiArgs, metavar is full list of all argument names.
303      Name += ' ';
304      Name += MetaVarName;
305    }
306    else {
307      // For MultiArgs<N>, if metavar not supplied, print <value> N times.
308      for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
309        Name += " <value>";
310      }
311    }
312    break;
313
314  case Option::FlagClass:
315    break;
316
317  case Option::SeparateClass: case Option::JoinedOrSeparateClass:
318  case Option::RemainingArgsClass: case Option::RemainingArgsJoinedClass:
319    Name += ' ';
320    LLVM_FALLTHROUGH;
321  case Option::JoinedClass: case Option::CommaJoinedClass:
322  case Option::JoinedAndSeparateClass:
323    if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
324      Name += MetaVarName;
325    else
326      Name += "<value>";
327    break;
328  }
329
330  return Name;
331}
332
333static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
334                                std::vector<std::pair<std::string,
335                                const char*> > &OptionHelp) {
336  OS << Title << ":\n";
337
338  // Find the maximum option length.
339  unsigned OptionFieldWidth = 0;
340  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
341    // Skip titles.
342    if (!OptionHelp[i].second)
343      continue;
344
345    // Limit the amount of padding we are willing to give up for alignment.
346    unsigned Length = OptionHelp[i].first.size();
347    if (Length <= 23)
348      OptionFieldWidth = std::max(OptionFieldWidth, Length);
349  }
350
351  const unsigned InitialPad = 2;
352  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
353    const std::string &Option = OptionHelp[i].first;
354    int Pad = OptionFieldWidth - int(Option.size());
355    OS.indent(InitialPad) << Option;
356
357    // Break on long option names.
358    if (Pad < 0) {
359      OS << "\n";
360      Pad = OptionFieldWidth + InitialPad;
361    }
362    OS.indent(Pad + 1) << OptionHelp[i].second << '\n';
363  }
364}
365
366static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
367  unsigned GroupID = Opts.getOptionGroupID(Id);
368
369  // If not in a group, return the default help group.
370  if (!GroupID)
371    return "OPTIONS";
372
373  // Abuse the help text of the option groups to store the "help group"
374  // name.
375  //
376  // FIXME: Split out option groups.
377  if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
378    return GroupHelp;
379
380  // Otherwise keep looking.
381  return getOptionHelpGroup(Opts, GroupID);
382}
383
384void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
385                         bool ShowHidden) const {
386  PrintHelp(OS, Name, Title, /*Include*/ 0, /*Exclude*/
387            (ShowHidden ? 0 : HelpHidden));
388}
389
390
391void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
392                         unsigned FlagsToInclude,
393                         unsigned FlagsToExclude) const {
394  OS << "OVERVIEW: " << Title << "\n";
395  OS << '\n';
396  OS << "USAGE: " << Name << " [options] <inputs>\n";
397  OS << '\n';
398
399  // Render help text into a map of group-name to a list of (option, help)
400  // pairs.
401  typedef std::map<std::string,
402                 std::vector<std::pair<std::string, const char*> > > helpmap_ty;
403  helpmap_ty GroupedOptionHelp;
404
405  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
406    unsigned Id = i + 1;
407
408    // FIXME: Split out option groups.
409    if (getOptionKind(Id) == Option::GroupClass)
410      continue;
411
412    unsigned Flags = getInfo(Id).Flags;
413    if (FlagsToInclude && !(Flags & FlagsToInclude))
414      continue;
415    if (Flags & FlagsToExclude)
416      continue;
417
418    if (const char *Text = getOptionHelpText(Id)) {
419      const char *HelpGroup = getOptionHelpGroup(*this, Id);
420      const std::string &OptName = getOptionHelpName(*this, Id);
421      GroupedOptionHelp[HelpGroup].push_back(std::make_pair(OptName, Text));
422    }
423  }
424
425  for (helpmap_ty::iterator it = GroupedOptionHelp .begin(),
426         ie = GroupedOptionHelp.end(); it != ie; ++it) {
427    if (it != GroupedOptionHelp .begin())
428      OS << "\n";
429    PrintHelpOptionList(OS, it->first, it->second);
430  }
431
432  OS.flush();
433}
434