OptTable.cpp revision 1ee21dc1e11abdc56102d0f54265af73f5468bf9 
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 <map>
18
19using namespace llvm;
20using namespace llvm::opt;
21
22// Ordering on Info. The ordering is *almost* lexicographic, with two
23// exceptions. First, '\0' comes at the end of the alphabet instead of
24// the beginning (thus options precede any other options which prefix
25// them). Second, for options with the same name, the less permissive
26// version should come first; a Flag option should precede a Joined
27// option, for example.
28
29static int StrCmpOptionName(const char *A, const char *B) {
30  char a = *A, b = *B;
31  while (a == b) {
32    if (a == '\0')
33      return 0;
34
35    a = *++A;
36    b = *++B;
37  }
38
39  if (a == '\0') // A is a prefix of B.
40    return 1;
41  if (b == '\0') // B is a prefix of A.
42    return -1;
43
44  // Otherwise lexicographic.
45  return (a < b) ? -1 : 1;
46}
47
48namespace llvm {
49namespace opt {
50
51static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
52  if (&A == &B)
53    return false;
54
55  if (int N = StrCmpOptionName(A.Name, B.Name))
56    return N == -1;
57
58  for (const char * const *APre = A.Prefixes,
59                  * const *BPre = B.Prefixes;
60                          *APre != 0 && *BPre != 0; ++APre, ++BPre) {
61    if (int N = StrCmpOptionName(*APre, *BPre))
62      return N == -1;
63  }
64
65  // Names are the same, check that classes are in order; exactly one
66  // should be joined, and it should succeed the other.
67  assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
68         "Unexpected classes for options with same name.");
69  return B.Kind == Option::JoinedClass;
70}
71
72// Support lower_bound between info and an option name.
73static inline bool operator<(const OptTable::Info &I, const char *Name) {
74  return StrCmpOptionName(I.Name, Name) == -1;
75}
76static inline bool operator<(const char *Name, const OptTable::Info &I) {
77  return StrCmpOptionName(Name, I.Name) == -1;
78}
79}
80}
81
82OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
83
84OptTable::OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos)
85  : OptionInfos(_OptionInfos),
86    NumOptionInfos(_NumOptionInfos),
87    TheInputOptionID(0),
88    TheUnknownOptionID(0),
89    FirstSearchableIndex(0)
90{
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 != 0; ++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 (std::find(PrefixChars.begin(), PrefixChars.end(), *C)
147            == PrefixChars.end())
148        PrefixChars.push_back(*C);
149  }
150}
151
152OptTable::~OptTable() {
153}
154
155const Option OptTable::getOption(OptSpecifier Opt) const {
156  unsigned id = Opt.getID();
157  if (id == 0)
158    return Option(0, 0);
159  assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
160  return Option(&getInfo(id), this);
161}
162
163static bool isInput(const llvm::StringSet<> &Prefixes, StringRef Arg) {
164  if (Arg == "-")
165    return true;
166  for (llvm::StringSet<>::const_iterator I = Prefixes.begin(),
167                                         E = Prefixes.end(); I != E; ++I)
168    if (Arg.startswith(I->getKey()))
169      return false;
170  return true;
171}
172
173/// \returns Matched size. 0 means no match.
174static unsigned matchOption(const OptTable::Info *I, StringRef Str) {
175  for (const char * const *Pre = I->Prefixes; *Pre != 0; ++Pre) {
176    StringRef Prefix(*Pre);
177    if (Str.startswith(Prefix) && Str.substr(Prefix.size()).startswith(I->Name))
178      return Prefix.size() + StringRef(I->Name).size();
179  }
180  return 0;
181}
182
183Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index) const {
184  unsigned Prev = Index;
185  const char *Str = Args.getArgString(Index);
186
187  // Anything that doesn't start with PrefixesUnion is an input, as is '-'
188  // itself.
189  if (isInput(PrefixesUnion, Str))
190    return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
191
192  const Info *Start = OptionInfos + FirstSearchableIndex;
193  const Info *End = OptionInfos + getNumOptions();
194  StringRef Name = StringRef(Str).ltrim(PrefixChars);
195
196  // Search for the first next option which could be a prefix.
197  Start = std::lower_bound(Start, End, Name.data());
198
199  // Options are stored in sorted order, with '\0' at the end of the
200  // alphabet. Since the only options which can accept a string must
201  // prefix it, we iteratively search for the next option which could
202  // be a prefix.
203  //
204  // FIXME: This is searching much more than necessary, but I am
205  // blanking on the simplest way to make it fast. We can solve this
206  // problem when we move to TableGen.
207  for (; Start != End; ++Start) {
208    unsigned ArgSize = 0;
209    // Scan for first option which is a proper prefix.
210    for (; Start != End; ++Start)
211      if ((ArgSize = matchOption(Start, Str)))
212        break;
213    if (Start == End)
214      break;
215
216    // See if this option matches.
217    if (Arg *A = Option(Start, this).accept(Args, Index, ArgSize))
218      return A;
219
220    // Otherwise, see if this argument was missing values.
221    if (Prev != Index)
222      return 0;
223  }
224
225  return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
226}
227
228InputArgList *OptTable::ParseArgs(const char* const *ArgBegin,
229                                  const char* const *ArgEnd,
230                                  unsigned &MissingArgIndex,
231                                  unsigned &MissingArgCount) const {
232  InputArgList *Args = new InputArgList(ArgBegin, ArgEnd);
233
234  // FIXME: Handle '@' args (or at least error on them).
235
236  MissingArgIndex = MissingArgCount = 0;
237  unsigned Index = 0, End = ArgEnd - ArgBegin;
238  while (Index < End) {
239    // Ignore empty arguments (other things may still take them as arguments).
240    if (Args->getArgString(Index)[0] == '\0') {
241      ++Index;
242      continue;
243    }
244
245    unsigned Prev = Index;
246    Arg *A = ParseOneArg(*Args, Index);
247    assert(Index > Prev && "Parser failed to consume argument.");
248
249    // Check for missing argument error.
250    if (!A) {
251      assert(Index >= End && "Unexpected parser error.");
252      assert(Index - Prev - 1 && "No missing arguments!");
253      MissingArgIndex = Prev;
254      MissingArgCount = Index - Prev - 1;
255      break;
256    }
257
258    Args->append(A);
259  }
260
261  return Args;
262}
263
264static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
265  const Option O = Opts.getOption(Id);
266  std::string Name = O.getPrefixedName();
267
268  // Add metavar, if used.
269  switch (O.getKind()) {
270  case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
271    llvm_unreachable("Invalid option with help text.");
272
273  case Option::MultiArgClass:
274    llvm_unreachable("Cannot print metavar for this kind of option.");
275
276  case Option::FlagClass:
277    break;
278
279  case Option::SeparateClass: case Option::JoinedOrSeparateClass:
280    Name += ' ';
281    // FALLTHROUGH
282  case Option::JoinedClass: case Option::CommaJoinedClass:
283  case Option::JoinedAndSeparateClass:
284    if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
285      Name += MetaVarName;
286    else
287      Name += "<value>";
288    break;
289  }
290
291  return Name;
292}
293
294static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
295                                std::vector<std::pair<std::string,
296                                const char*> > &OptionHelp) {
297  OS << Title << ":\n";
298
299  // Find the maximum option length.
300  unsigned OptionFieldWidth = 0;
301  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
302    // Skip titles.
303    if (!OptionHelp[i].second)
304      continue;
305
306    // Limit the amount of padding we are willing to give up for alignment.
307    unsigned Length = OptionHelp[i].first.size();
308    if (Length <= 23)
309      OptionFieldWidth = std::max(OptionFieldWidth, Length);
310  }
311
312  const unsigned InitialPad = 2;
313  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
314    const std::string &Option = OptionHelp[i].first;
315    int Pad = OptionFieldWidth - int(Option.size());
316    OS.indent(InitialPad) << Option;
317
318    // Break on long option names.
319    if (Pad < 0) {
320      OS << "\n";
321      Pad = OptionFieldWidth + InitialPad;
322    }
323    OS.indent(Pad + 1) << OptionHelp[i].second << '\n';
324  }
325}
326
327static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
328  unsigned GroupID = Opts.getOptionGroupID(Id);
329
330  // If not in a group, return the default help group.
331  if (!GroupID)
332    return "OPTIONS";
333
334  // Abuse the help text of the option groups to store the "help group"
335  // name.
336  //
337  // FIXME: Split out option groups.
338  if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
339    return GroupHelp;
340
341  // Otherwise keep looking.
342  return getOptionHelpGroup(Opts, GroupID);
343}
344
345void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
346                         bool ShowHidden) const {
347  PrintHelp(OS, Name, Title, /*Include*/ 0, /*Exclude*/
348            (ShowHidden ? 0 : HelpHidden));
349}
350
351
352void OptTable::PrintHelp(raw_ostream &OS, const char *Name, const char *Title,
353                         unsigned FlagsToInclude,
354                         unsigned FlagsToExclude) const {
355  OS << "OVERVIEW: " << Title << "\n";
356  OS << '\n';
357  OS << "USAGE: " << Name << " [options] <inputs>\n";
358  OS << '\n';
359
360  // Render help text into a map of group-name to a list of (option, help)
361  // pairs.
362  typedef std::map<std::string,
363                 std::vector<std::pair<std::string, const char*> > > helpmap_ty;
364  helpmap_ty GroupedOptionHelp;
365
366  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
367    unsigned Id = i + 1;
368
369    // FIXME: Split out option groups.
370    if (getOptionKind(Id) == Option::GroupClass)
371      continue;
372
373    unsigned Flags = getInfo(Id).Flags;
374    if (FlagsToInclude && !(Flags & FlagsToInclude))
375      continue;
376    if (Flags & FlagsToExclude)
377      continue;
378
379    if (const char *Text = getOptionHelpText(Id)) {
380      const char *HelpGroup = getOptionHelpGroup(*this, Id);
381      const std::string &OptName = getOptionHelpName(*this, Id);
382      GroupedOptionHelp[HelpGroup].push_back(std::make_pair(OptName, Text));
383    }
384  }
385
386  for (helpmap_ty::iterator it = GroupedOptionHelp .begin(),
387         ie = GroupedOptionHelp.end(); it != ie; ++it) {
388    if (it != GroupedOptionHelp .begin())
389      OS << "\n";
390    PrintHelpOptionList(OS, it->first, it->second);
391  }
392
393  OS.flush();
394}
395