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      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 CLANG_DRIVER_OPTTABLE_H
     11 #define CLANG_DRIVER_OPTTABLE_H
     12 
     13 #include "clang/Basic/LLVM.h"
     14 #include "clang/Driver/OptSpecifier.h"
     15 
     16 namespace clang {
     17 namespace driver {
     18 namespace options {
     19   enum DriverFlag {
     20     DriverOption     = (1 << 0),
     21     HelpHidden       = (1 << 1),
     22     LinkerInput      = (1 << 2),
     23     NoArgumentUnused = (1 << 3),
     24     NoForward        = (1 << 4),
     25     RenderAsInput    = (1 << 5),
     26     RenderJoined     = (1 << 6),
     27     RenderSeparate   = (1 << 7),
     28     Unsupported      = (1 << 8)
     29   };
     30 }
     31 
     32   class Arg;
     33   class ArgList;
     34   class InputArgList;
     35   class Option;
     36 
     37   /// OptTable - Provide access to the Option info table.
     38   ///
     39   /// The OptTable class provides a layer of indirection which allows Option
     40   /// instance to be created lazily. In the common case, only a few options will
     41   /// be needed at runtime; the OptTable class maintains enough information to
     42   /// parse command lines without instantiating Options, while letting other
     43   /// parts of the driver still use Option instances where convenient.
     44   class OptTable {
     45   public:
     46     /// Info - Entry for a single option instance in the option data table.
     47     struct Info {
     48       const char *Name;
     49       const char *HelpText;
     50       const char *MetaVar;
     51       unsigned char Kind;
     52       unsigned char Param;
     53       unsigned short Flags;
     54       unsigned short GroupID;
     55       unsigned short AliasID;
     56     };
     57 
     58   private:
     59     /// The static option information table.
     60     const Info *OptionInfos;
     61     unsigned NumOptionInfos;
     62 
     63     /// The lazily constructed options table, indexed by option::ID - 1.
     64     mutable Option **Options;
     65 
     66     /// Prebound input option instance.
     67     const Option *TheInputOption;
     68 
     69     /// Prebound unknown option instance.
     70     const Option *TheUnknownOption;
     71 
     72     /// The index of the first option which can be parsed (i.e., is not a
     73     /// special option like 'input' or 'unknown', and is not an option group).
     74     unsigned FirstSearchableIndex;
     75 
     76   private:
     77     const Info &getInfo(OptSpecifier Opt) const {
     78       unsigned id = Opt.getID();
     79       assert(id > 0 && id - 1 < getNumOptions() && "Invalid Option ID.");
     80       return OptionInfos[id - 1];
     81     }
     82 
     83     Option *CreateOption(unsigned id) const;
     84 
     85   protected:
     86     OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos);
     87   public:
     88     ~OptTable();
     89 
     90     /// getNumOptions - Return the total number of option classes.
     91     unsigned getNumOptions() const { return NumOptionInfos; }
     92 
     93     /// getOption - Get the given \arg id's Option instance, lazily creating it
     94     /// if necessary.
     95     ///
     96     /// \return The option, or null for the INVALID option id.
     97     const Option *getOption(OptSpecifier Opt) const {
     98       unsigned id = Opt.getID();
     99       if (id == 0)
    100         return 0;
    101 
    102       assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
    103       Option *&Entry = Options[id - 1];
    104       if (!Entry)
    105         Entry = CreateOption(id);
    106       return Entry;
    107     }
    108 
    109     /// getOptionName - Lookup the name of the given option.
    110     const char *getOptionName(OptSpecifier id) const {
    111       return getInfo(id).Name;
    112     }
    113 
    114     /// getOptionKind - Get the kind of the given option.
    115     unsigned getOptionKind(OptSpecifier id) const {
    116       return getInfo(id).Kind;
    117     }
    118 
    119     /// getOptionGroupID - Get the group id for the given option.
    120     unsigned getOptionGroupID(OptSpecifier id) const {
    121       return getInfo(id).GroupID;
    122     }
    123 
    124     /// isOptionHelpHidden - Should the help for the given option be hidden by
    125     /// default.
    126     bool isOptionHelpHidden(OptSpecifier id) const {
    127       return getInfo(id).Flags & options::HelpHidden;
    128     }
    129 
    130     /// getOptionHelpText - Get the help text to use to describe this option.
    131     const char *getOptionHelpText(OptSpecifier id) const {
    132       return getInfo(id).HelpText;
    133     }
    134 
    135     /// getOptionMetaVar - Get the meta-variable name to use when describing
    136     /// this options values in the help text.
    137     const char *getOptionMetaVar(OptSpecifier id) const {
    138       return getInfo(id).MetaVar;
    139     }
    140 
    141     /// ParseOneArg - Parse a single argument; returning the new argument and
    142     /// updating Index.
    143     ///
    144     /// \param [in] [out] Index - The current parsing position in the argument
    145     /// string list; on return this will be the index of the next argument
    146     /// string to parse.
    147     ///
    148     /// \return - The parsed argument, or 0 if the argument is missing values
    149     /// (in which case Index still points at the conceptual next argument string
    150     /// to parse).
    151     Arg *ParseOneArg(const ArgList &Args, unsigned &Index) const;
    152 
    153     /// ParseArgs - Parse an list of arguments into an InputArgList.
    154     ///
    155     /// The resulting InputArgList will reference the strings in [ArgBegin,
    156     /// ArgEnd), and their lifetime should extend past that of the returned
    157     /// InputArgList.
    158     ///
    159     /// The only error that can occur in this routine is if an argument is
    160     /// missing values; in this case \arg MissingArgCount will be non-zero.
    161     ///
    162     /// \param ArgBegin - The beginning of the argument vector.
    163     /// \param ArgEnd - The end of the argument vector.
    164     /// \param MissingArgIndex - On error, the index of the option which could
    165     /// not be parsed.
    166     /// \param MissingArgCount - On error, the number of missing options.
    167     /// \return - An InputArgList; on error this will contain all the options
    168     /// which could be parsed.
    169     InputArgList *ParseArgs(const char* const *ArgBegin,
    170                             const char* const *ArgEnd,
    171                             unsigned &MissingArgIndex,
    172                             unsigned &MissingArgCount) const;
    173 
    174     /// PrintHelp - Render the help text for an option table.
    175     ///
    176     /// \param OS - The stream to write the help text to.
    177     /// \param Name - The name to use in the usage line.
    178     /// \param Title - The title to use in the usage line.
    179     /// \param ShowHidden - Whether help-hidden arguments should be shown.
    180     void PrintHelp(raw_ostream &OS, const char *Name,
    181                    const char *Title, bool ShowHidden = false) const;
    182   };
    183 }
    184 }
    185 
    186 #endif
    187