OptTable.h revision 1ee21dc1e11abdc56102d0f54265af73f5468bf9 
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  };
48
49private:
50  /// \brief The static option information table.
51  const Info *OptionInfos;
52  unsigned NumOptionInfos;
53
54  unsigned TheInputOptionID;
55  unsigned TheUnknownOptionID;
56
57  /// The index of the first option which can be parsed (i.e., is not a
58  /// special option like 'input' or 'unknown', and is not an option group).
59  unsigned FirstSearchableIndex;
60
61  /// The union of all option prefixes. If an argument does not begin with
62  /// one of these, it is an input.
63  StringSet<> PrefixesUnion;
64  std::string PrefixChars;
65
66private:
67  const Info &getInfo(OptSpecifier Opt) const {
68    unsigned id = Opt.getID();
69    assert(id > 0 && id - 1 < getNumOptions() && "Invalid Option ID.");
70    return OptionInfos[id - 1];
71  }
72
73protected:
74  OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos);
75public:
76  ~OptTable();
77
78  /// \brief Return the total number of option classes.
79  unsigned getNumOptions() const { return NumOptionInfos; }
80
81  /// \brief Get the given Opt's Option instance, lazily creating it
82  /// if necessary.
83  ///
84  /// \return The option, or null for the INVALID option id.
85  const Option getOption(OptSpecifier Opt) const;
86
87  /// \brief Lookup the name of the given option.
88  const char *getOptionName(OptSpecifier id) const {
89    return getInfo(id).Name;
90  }
91
92  /// \brief Get the kind of the given option.
93  unsigned getOptionKind(OptSpecifier id) const {
94    return getInfo(id).Kind;
95  }
96
97  /// \brief Get the group id for the given option.
98  unsigned getOptionGroupID(OptSpecifier id) const {
99    return getInfo(id).GroupID;
100  }
101
102  /// \brief Get the help text to use to describe this option.
103  const char *getOptionHelpText(OptSpecifier id) const {
104    return getInfo(id).HelpText;
105  }
106
107  /// \brief Get the meta-variable name to use when describing
108  /// this options values in the help text.
109  const char *getOptionMetaVar(OptSpecifier id) const {
110    return getInfo(id).MetaVar;
111  }
112
113  /// \brief Parse a single argument; returning the new argument and
114  /// updating Index.
115  ///
116  /// \param [in,out] Index - The current parsing position in the argument
117  /// string list; on return this will be the index of the next argument
118  /// string to parse.
119  ///
120  /// \return The parsed argument, or 0 if the argument is missing values
121  /// (in which case Index still points at the conceptual next argument string
122  /// to parse).
123  Arg *ParseOneArg(const ArgList &Args, unsigned &Index) const;
124
125  /// \brief Parse an list of arguments into an InputArgList.
126  ///
127  /// The resulting InputArgList will reference the strings in [\p ArgBegin,
128  /// \p ArgEnd), and their lifetime should extend past that of the returned
129  /// InputArgList.
130  ///
131  /// The only error that can occur in this routine is if an argument is
132  /// missing values; in this case \p MissingArgCount will be non-zero.
133  ///
134  /// \param ArgBegin - The beginning of the argument vector.
135  /// \param ArgEnd - The end of the argument vector.
136  /// \param MissingArgIndex - On error, the index of the option which could
137  /// not be parsed.
138  /// \param MissingArgCount - On error, the number of missing options.
139  /// \return An InputArgList; on error this will contain all the options
140  /// which could be parsed.
141  InputArgList *ParseArgs(const char* const *ArgBegin,
142                          const char* const *ArgEnd,
143                          unsigned &MissingArgIndex,
144                          unsigned &MissingArgCount) const;
145
146  /// \brief Render the help text for an option table.
147  ///
148  /// \param OS - The stream to write the help text to.
149  /// \param Name - The name to use in the usage line.
150  /// \param Title - The title to use in the usage line.
151  /// \param FlagsToInclude - If non-zero, only include options with any
152  ///                         of these flags set.
153  /// \param FlagsToExclude - Exclude options with any of these flags set.
154  void PrintHelp(raw_ostream &OS, const char *Name,
155                 const char *Title, unsigned FlagsToInclude,
156                 unsigned FlagsToExclude) const;
157
158  void PrintHelp(raw_ostream &OS, const char *Name,
159                  const char *Title, bool ShowHidden = false) const;
160};
161} // end namespace opt
162} // end namespace llvm
163
164#endif
165