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/ArrayRef.h"
14 #include "llvm/ADT/StringSet.h"
15 #include "llvm/Option/OptSpecifier.h"
16 
17 namespace llvm {
18 class raw_ostream;
19 namespace opt {
20 class Arg;
21 class ArgList;
22 class InputArgList;
23 class Option;
24 
25 /// \brief Provide access to the Option info table.
26 ///
27 /// The OptTable class provides a layer of indirection which allows Option
28 /// instance to be created lazily. In the common case, only a few options will
29 /// be needed at runtime; the OptTable class maintains enough information to
30 /// parse command lines without instantiating Options, while letting other
31 /// parts of the driver still use Option instances where convenient.
32 class OptTable {
33 public:
34   /// \brief Entry for a single option instance in the option data table.
35   struct Info {
36     /// A null terminated array of prefix strings to apply to name while
37     /// matching.
38     const char *const *Prefixes;
39     const char *Name;
40     const char *HelpText;
41     const char *MetaVar;
42     unsigned ID;
43     unsigned char Kind;
44     unsigned char Param;
45     unsigned short Flags;
46     unsigned short GroupID;
47     unsigned short AliasID;
48     const char *AliasArgs;
49   };
50 
51 private:
52   /// \brief The static option information table.
53   ArrayRef<Info> OptionInfos;
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 
68 private:
getInfo(OptSpecifier Opt)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 
75 protected:
76   OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase = false);
77 
78 public:
79   ~OptTable();
80 
81   /// \brief Return the total number of option classes.
getNumOptions()82   unsigned getNumOptions() const { return OptionInfos.size(); }
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.
getOptionName(OptSpecifier id)91   const char *getOptionName(OptSpecifier id) const {
92     return getInfo(id).Name;
93   }
94 
95   /// \brief Get the kind of the given option.
getOptionKind(OptSpecifier id)96   unsigned getOptionKind(OptSpecifier id) const {
97     return getInfo(id).Kind;
98   }
99 
100   /// \brief Get the group id for the given option.
getOptionGroupID(OptSpecifier id)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.
getOptionHelpText(OptSpecifier id)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.
getOptionMetaVar(OptSpecifier id)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 MissingArgIndex - On error, the index of the option which could
144   /// not be parsed.
145   /// \param MissingArgCount - On error, the number of missing options.
146   /// \param FlagsToInclude - Only parse options with any of these flags.
147   /// Zero is the default which includes all flags.
148   /// \param FlagsToExclude - Don't parse options with this flag.  Zero
149   /// is the default and means exclude nothing.
150   /// \return An InputArgList; on error this will contain all the options
151   /// which could be parsed.
152   InputArgList ParseArgs(ArrayRef<const char *> Args, unsigned &MissingArgIndex,
153                          unsigned &MissingArgCount, unsigned FlagsToInclude = 0,
154                          unsigned FlagsToExclude = 0) const;
155 
156   /// \brief Render the help text for an option table.
157   ///
158   /// \param OS - The stream to write the help text to.
159   /// \param Name - The name to use in the usage line.
160   /// \param Title - The title to use in the usage line.
161   /// \param FlagsToInclude - If non-zero, only include options with any
162   ///                         of these flags set.
163   /// \param FlagsToExclude - Exclude options with any of these flags set.
164   void PrintHelp(raw_ostream &OS, const char *Name,
165                  const char *Title, unsigned FlagsToInclude,
166                  unsigned FlagsToExclude) const;
167 
168   void PrintHelp(raw_ostream &OS, const char *Name,
169                   const char *Title, bool ShowHidden = false) const;
170 };
171 } // end namespace opt
172 } // end namespace llvm
173 
174 #endif
175