OptTable.h revision 263508 
1//===--- OptTable.h - Option Table ------------------------------*- C++ -*-===//
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#ifndef LLVM_OPTION_OPTTABLE_H
11#define LLVM_OPTION_OPTTABLE_H
12
13#include "llvm/ADT/StringSet.h"
14#include "llvm/Option/OptSpecifier.h"
15
16namespace llvm {
17class raw_ostream;
18namespace opt {
19class Arg;
20class ArgList;
21class InputArgList;
22class Option;
23
24/// \brief Provide access to the Option info table.
25///
26/// The OptTable class provides a layer of indirection which allows Option
27/// instance to be created lazily. In the common case, only a few options will
28/// be needed at runtime; the OptTable class maintains enough information to
29/// parse command lines without instantiating Options, while letting other
30/// parts of the driver still use Option instances where convenient.
31class OptTable {
32public:
33  /// \brief Entry for a single option instance in the option data table.
34  struct Info {
35    /// A null terminated array of prefix strings to apply to name while
36    /// matching.
37    const char *const *Prefixes;
38    const char *Name;
39    const char *HelpText;
40    const char *MetaVar;
41    unsigned ID;
42    unsigned char Kind;
43    unsigned char Param;
44    unsigned short Flags;
45    unsigned short GroupID;
46    unsigned short AliasID;
47    const char *AliasArgs;
48  };
49
50private:
51  /// \brief The static option information table.
52  const Info *OptionInfos;
53  unsigned NumOptionInfos;
54  bool IgnoreCase;
55
56  unsigned TheInputOptionID;
57  unsigned TheUnknownOptionID;
58
59  /// The index of the first option which can be parsed (i.e., is not a
60  /// special option like 'input' or 'unknown', and is not an option group).
61  unsigned FirstSearchableIndex;
62
63  /// The union of all option prefixes. If an argument does not begin with
64  /// one of these, it is an input.
65  StringSet<> PrefixesUnion;
66  std::string PrefixChars;
67
68private:
69  const Info &getInfo(OptSpecifier Opt) const {
70    unsigned id = Opt.getID();
71    assert(id > 0 && id - 1 < getNumOptions() && "Invalid Option ID.");
72    return OptionInfos[id - 1];
73  }
74
75protected:
76  OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos,
77           bool _IgnoreCase = false);
78public:
79  ~OptTable();
80
81  /// \brief Return the total number of option classes.
82  unsigned getNumOptions() const { return NumOptionInfos; }
83
84  /// \brief Get the given Opt's Option instance, lazily creating it
85  /// if necessary.
86  ///
87  /// \return The option, or null for the INVALID option id.
88  const Option getOption(OptSpecifier Opt) const;
89
90  /// \brief Lookup the name of the given option.
91  const char *getOptionName(OptSpecifier id) const {
92    return getInfo(id).Name;
93  }
94
95  /// \brief Get the kind of the given option.
96  unsigned getOptionKind(OptSpecifier id) const {
97    return getInfo(id).Kind;
98  }
99
100  /// \brief Get the group id for the given option.
101  unsigned getOptionGroupID(OptSpecifier id) const {
102    return getInfo(id).GroupID;
103  }
104
105  /// \brief Get the help text to use to describe this option.
106  const char *getOptionHelpText(OptSpecifier id) const {
107    return getInfo(id).HelpText;
108  }
109
110  /// \brief Get the meta-variable name to use when describing
111  /// this options values in the help text.
112  const char *getOptionMetaVar(OptSpecifier id) const {
113    return getInfo(id).MetaVar;
114  }
115
116  /// \brief Parse a single argument; returning the new argument and
117  /// updating Index.
118  ///
119  /// \param [in,out] Index - The current parsing position in the argument
120  /// string list; on return this will be the index of the next argument
121  /// string to parse.
122  /// \param [in] FlagsToInclude - Only parse options with any of these flags.
123  /// Zero is the default which includes all flags.
124  /// \param [in] FlagsToExclude - Don't parse options with this flag.  Zero
125  /// is the default and means exclude nothing.
126  ///
127  /// \return The parsed argument, or 0 if the argument is missing values
128  /// (in which case Index still points at the conceptual next argument string
129  /// to parse).
130  Arg *ParseOneArg(const ArgList &Args, unsigned &Index,
131                   unsigned FlagsToInclude = 0,
132                   unsigned FlagsToExclude = 0) const;
133
134  /// \brief Parse an list of arguments into an InputArgList.
135  ///
136  /// The resulting InputArgList will reference the strings in [\p ArgBegin,
137  /// \p ArgEnd), and their lifetime should extend past that of the returned
138  /// InputArgList.
139  ///
140  /// The only error that can occur in this routine is if an argument is
141  /// missing values; in this case \p MissingArgCount will be non-zero.
142  ///
143  /// \param ArgBegin - The beginning of the argument vector.
144  /// \param ArgEnd - The end of the argument vector.
145  /// \param MissingArgIndex - On error, the index of the option which could
146  /// not be parsed.
147  /// \param MissingArgCount - On error, the number of missing options.
148  /// \param FlagsToInclude - Only parse options with any of these flags.
149  /// Zero is the default which includes all flags.
150  /// \param FlagsToExclude - Don't parse options with this flag.  Zero
151  /// is the default and means exclude nothing.
152  /// \return An InputArgList; on error this will contain all the options
153  /// which could be parsed.
154  InputArgList *ParseArgs(const char* const *ArgBegin,
155                          const char* const *ArgEnd,
156                          unsigned &MissingArgIndex,
157                          unsigned &MissingArgCount,
158                          unsigned FlagsToInclude = 0,
159                          unsigned FlagsToExclude = 0) const;
160
161  /// \brief Render the help text for an option table.
162  ///
163  /// \param OS - The stream to write the help text to.
164  /// \param Name - The name to use in the usage line.
165  /// \param Title - The title to use in the usage line.
166  /// \param FlagsToInclude - If non-zero, only include options with any
167  ///                         of these flags set.
168  /// \param FlagsToExclude - Exclude options with any of these flags set.
169  void PrintHelp(raw_ostream &OS, const char *Name,
170                 const char *Title, unsigned FlagsToInclude,
171                 unsigned FlagsToExclude) const;
172
173  void PrintHelp(raw_ostream &OS, const char *Name,
174                  const char *Title, bool ShowHidden = false) const;
175};
176} // end namespace opt
177} // end namespace llvm
178
179#endif
180