Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- OptTable.h - Option Table --------------------------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_OPTION_OPTTABLE_H

#define LLVM_OPTION_OPTTABLE_H

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Option/OptSpecifier.h"

#include "llvm/Support/StringSaver.h"

#include <cassert>

#include <string>

#include <vector>

namespace llvm {

class raw_ostream;

template <typename Fn> class function_ref;

namespace opt {

class Arg;

class ArgList;

class InputArgList;

class Option;

/// Provide access to the Option info table.

///

/// The OptTable class provides a layer of indirection which allows Option

/// instance to be created lazily. In the common case, only a few options will

/// be needed at runtime; the OptTable class maintains enough information to

/// parse command lines without instantiating Options, while letting other

/// parts of the driver still use Option instances where convenient.

class OptTable {

public:

  /// Entry for a single option instance in the option data table.

  struct Info {

    /// A null terminated array of prefix strings to apply to name while

    /// matching.

    ArrayRef<StringLiteral> Prefixes;

    StringRef Name;

    const char *HelpText;

    const char *MetaVar;

    unsigned ID;

    unsigned char Kind;

    unsigned char Param;

    unsigned int Flags;

    unsigned short GroupID;

    unsigned short AliasID;

    const char *AliasArgs;

    const char *Values;

  };

private:

  /// The option information table.

  ArrayRef<Info> OptionInfos;

  bool IgnoreCase;

  bool GroupedShortOptions = false;

  const char *EnvVar = nullptr;

  unsigned InputOptionID = 0;

  unsigned UnknownOptionID = 0;

protected:

  /// The index of the first option which can be parsed (i.e., is not a

  /// special option like 'input' or 'unknown', and is not an option group).

  unsigned FirstSearchableIndex = 0;

  /// The union of the first element of all option prefixes.

  SmallString<8> PrefixChars;

  /// The union of all option prefixes. If an argument does not begin with

  /// one of these, it is an input.

  virtual ArrayRef<StringLiteral> getPrefixesUnion() const = 0;

private:

  const Info &getInfo(OptSpecifier Opt) const {

    unsigned id = Opt.getID();

    assert(id > 0 && id - 1 < getNumOptions() && "Invalid Option ID.");

    return OptionInfos[id - 1];

  }

  std::unique_ptr<Arg> parseOneArgGrouped(InputArgList &Args,

                                          unsigned &Index) const;

protected:

  /// Initialize OptTable using Tablegen'ed OptionInfos. Child class must

  /// manually call \c buildPrefixChars once they are fully constructed.

  OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase = false);

  /// Build (or rebuild) the PrefixChars member.

  void buildPrefixChars();

public:

  virtual ~OptTable();

  /// Return the total number of option classes.

  unsigned getNumOptions() const { return OptionInfos.size(); }

  /// Get the given Opt's Option instance, lazily creating it

  /// if necessary.

  ///

  /// \return The option, or null for the INVALID option id.

  const Option getOption(OptSpecifier Opt) const;

  /// Lookup the name of the given option.

  StringRef getOptionName(OptSpecifier id) const { return getInfo(id).Name; }

  /// Get the kind of the given option.

  unsigned getOptionKind(OptSpecifier id) const {

    return getInfo(id).Kind;

  }

  /// Get the group id for the given option.

  unsigned getOptionGroupID(OptSpecifier id) const {

    return getInfo(id).GroupID;

  }

  /// Get the help text to use to describe this option.

  const char *getOptionHelpText(OptSpecifier id) const {

    return getInfo(id).HelpText;

  }

  /// Get the meta-variable name to use when describing

  /// this options values in the help text.

  const char *getOptionMetaVar(OptSpecifier id) const {

    return getInfo(id).MetaVar;

  }

  /// Specify the environment variable where initial options should be read.

  void setInitialOptionsFromEnvironment(const char *E) { EnvVar = E; }

  /// Support grouped short options. e.g. -ab represents -a -b.

  void setGroupedShortOptions(bool Value) { GroupedShortOptions = Value; }

  /// Find possible value for given flags. This is used for shell

  /// autocompletion.

  ///

  /// \param [in] Option - Key flag like "-stdlib=" when "-stdlib=l"

  /// was passed to clang.

  ///

  /// \param [in] Arg - Value which we want to autocomplete like "l"

  /// when "-stdlib=l" was passed to clang.

  ///

  /// \return The vector of possible values.

  std::vector<std::string> suggestValueCompletions(StringRef Option,

                                                   StringRef Arg) const;

  /// Find flags from OptTable which starts with Cur.

  ///

  /// \param [in] Cur - String prefix that all returned flags need

  //  to start with.

  ///

  /// \return The vector of flags which start with Cur.

  std::vector<std::string> findByPrefix(StringRef Cur,

                                        unsigned int DisableFlags) const;

  /// Find the OptTable option that most closely matches the given string.

  ///

  /// \param [in] Option - A string, such as "-stdlibs=l", that represents user

  /// input of an option that may not exist in the OptTable. Note that the

  /// string includes prefix dashes "-" as well as values "=l".

  /// \param [out] NearestString - The nearest option string found in the

  /// OptTable.

  /// \param [in] FlagsToInclude - Only find options with any of these flags.

  /// Zero is the default, which includes all flags.

  /// \param [in] FlagsToExclude - Don't find options with this flag. Zero

  /// is the default, and means exclude nothing.

  /// \param [in] MinimumLength - Don't find options shorter than this length.

  /// For example, a minimum length of 3 prevents "-x" from being considered

  /// near to "-S".

  /// \param [in] MaximumDistance - Don't find options whose distance is greater

  /// than this value.

  ///

  /// \return The edit distance of the nearest string found.

  unsigned findNearest(StringRef Option, std::string &NearestString,

                       unsigned FlagsToInclude = 0, unsigned FlagsToExclude = 0,

                       unsigned MinimumLength = 4,

                       unsigned MaximumDistance = UINT_MAX) const;

  bool findExact(StringRef Option, std::string &ExactString,

                 unsigned FlagsToInclude = 0,

                 unsigned FlagsToExclude = 0) const {

    return findNearest(Option, ExactString, FlagsToInclude, FlagsToExclude, 4,

                       0) == 0;

  }

  /// Parse a single argument; returning the new argument and

  /// updating Index.

  ///

  /// \param [in,out] Index - The current parsing position in the argument

  /// string list; on return this will be the index of the next argument

  /// string to parse.

  /// \param [in] FlagsToInclude - Only parse options with any of these flags.

  /// Zero is the default which includes all flags.

  /// \param [in] FlagsToExclude - Don't parse options with this flag.  Zero

  /// is the default and means exclude nothing.

  ///

  /// \return The parsed argument, or 0 if the argument is missing values

  /// (in which case Index still points at the conceptual next argument string

  /// to parse).

  std::unique_ptr<Arg> ParseOneArg(const ArgList &Args, unsigned &Index,

                                   unsigned FlagsToInclude = 0,

                                   unsigned FlagsToExclude = 0) const;

  /// Parse an list of arguments into an InputArgList.

  ///

  /// The resulting InputArgList will reference the strings in [\p ArgBegin,

  /// \p ArgEnd), and their lifetime should extend past that of the returned

  /// InputArgList.

  ///

  /// The only error that can occur in this routine is if an argument is

  /// missing values; in this case \p MissingArgCount will be non-zero.

  ///

  /// \param MissingArgIndex - On error, the index of the option which could

  /// not be parsed.

  /// \param MissingArgCount - On error, the number of missing options.

  /// \param FlagsToInclude - Only parse options with any of these flags.

  /// Zero is the default which includes all flags.

  /// \param FlagsToExclude - Don't parse options with this flag.  Zero

  /// is the default and means exclude nothing.

  /// \return An InputArgList; on error this will contain all the options

  /// which could be parsed.

  InputArgList ParseArgs(ArrayRef<const char *> Args, unsigned &MissingArgIndex,

                         unsigned &MissingArgCount, unsigned FlagsToInclude = 0,

                         unsigned FlagsToExclude = 0) const;

  /// A convenience helper which handles optional initial options populated from

  /// an environment variable, expands response files recursively and parses

  /// options.

  ///

  /// \param ErrorFn - Called on a formatted error message for missing arguments

  /// or unknown options.

  /// \return An InputArgList; on error this will contain all the options which

  /// could be parsed.

  InputArgList parseArgs(int Argc, char *const *Argv, OptSpecifier Unknown,

                         StringSaver &Saver,

                         function_ref<void(StringRef)> ErrorFn) const;

  /// Render the help text for an option table.

  ///

  /// \param OS - The stream to write the help text to.

  /// \param Usage - USAGE: Usage

  /// \param Title - OVERVIEW: Title

  /// \param FlagsToInclude - If non-zero, only include options with any

  ///                         of these flags set.

  /// \param FlagsToExclude - Exclude options with any of these flags set.

  /// \param ShowAllAliases - If true, display all options including aliases

  ///                         that don't have help texts. By default, we display

  ///                         only options that are not hidden and have help

  ///                         texts.

  void printHelp(raw_ostream &OS, const char *Usage, const char *Title,

                 unsigned FlagsToInclude, unsigned FlagsToExclude,

                 bool ShowAllAliases) const;

  void printHelp(raw_ostream &OS, const char *Usage, const char *Title,

                 bool ShowHidden = false, bool ShowAllAliases = false) const;

};

/// Specialization of OptTable

class GenericOptTable : public OptTable {

  SmallVector<StringLiteral> PrefixesUnionBuffer;

protected:

  GenericOptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase = false);

  ArrayRef<StringLiteral> getPrefixesUnion() const final {

    return PrefixesUnionBuffer;

  }

};

class PrecomputedOptTable : public OptTable {

  ArrayRef<StringLiteral> PrefixesUnion;

protected:

  PrecomputedOptTable(ArrayRef<Info> OptionInfos,

                      ArrayRef<StringLiteral> PrefixesTable,

                      bool IgnoreCase = false)

      : OptTable(OptionInfos, IgnoreCase), PrefixesUnion(PrefixesTable) {

    buildPrefixChars();

  }

  ArrayRef<StringLiteral> getPrefixesUnion() const final {

    return PrefixesUnion;

  }

};

} // end namespace opt

} // end namespace llvm

#endif // LLVM_OPTION_OPTTABLE_H