Copy clang/Driver/<Option parsing stuff> to llvm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169344 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Option/OptTable.h

@@ -0,0 +1,161 @@
+//===--- OptTable.h - Option Table ------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_OPTTABLE_H
+#define LLVM_SUPPORT_OPTTABLE_H
+
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Option/OptSpecifier.h"
+
+namespace llvm {
+class raw_ostream;
+namespace opt {
+class Arg;
+class ArgList;
+class InputArgList;
+class Option;
+
+/// \brief 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:
+  /// \brief 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.
+    const char *const *Prefixes;
+    const char *Name;
+    const char *HelpText;
+    const char *MetaVar;
+    unsigned ID;
+    unsigned char Kind;
+    unsigned char Param;
+    unsigned short Flags;
+    unsigned short GroupID;
+    unsigned short AliasID;
+  };
+
+private:
+  /// \brief The static option information table.
+  const Info *OptionInfos;
+  unsigned NumOptionInfos;
+
+  unsigned TheInputOptionID;
+  unsigned TheUnknownOptionID;
+
+  /// 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;
+
+  /// The union of all option prefixes. If an argument does not begin with
+  /// one of these, it is an input.
+  StringSet<> PrefixesUnion;
+  std::string PrefixChars;
+
+private:
+  const Info &getInfo(OptSpecifier Opt) const {
+    unsigned id = Opt.getID();
+    assert(id > 0 && id - 1 < getNumOptions() && "Invalid Option ID.");
+    return OptionInfos[id - 1];
+  }
+
+protected:
+  OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos);
+public:
+  ~OptTable();
+
+  /// \brief Return the total number of option classes.
+  unsigned getNumOptions() const { return NumOptionInfos; }
+
+  /// \brief 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;
+
+  /// \brief Lookup the name of the given option.
+  const char *getOptionName(OptSpecifier id) const {
+    return getInfo(id).Name;
+  }
+
+  /// \brief Get the kind of the given option.
+  unsigned getOptionKind(OptSpecifier id) const {
+    return getInfo(id).Kind;
+  }
+
+  /// \brief Get the group id for the given option.
+  unsigned getOptionGroupID(OptSpecifier id) const {
+    return getInfo(id).GroupID;
+  }
+
+  /// \brief Should the help for the given option be hidden by default.
+  bool isOptionHelpHidden(OptSpecifier id) const;
+
+  /// \brief Get the help text to use to describe this option.
+  const char *getOptionHelpText(OptSpecifier id) const {
+    return getInfo(id).HelpText;
+  }
+
+  /// \brief 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;
+  }
+
+  /// \brief 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.
+  ///
+  /// \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).
+  Arg *ParseOneArg(const ArgList &Args, unsigned &Index) const;
+
+  /// \brief 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 ArgBegin - The beginning of the argument vector.
+  /// \param ArgEnd - The end of the argument vector.
+  /// \param MissingArgIndex - On error, the index of the option which could
+  /// not be parsed.
+  /// \param MissingArgCount - On error, the number of missing options.
+  /// \return An InputArgList; on error this will contain all the options
+  /// which could be parsed.
+  InputArgList *ParseArgs(const char* const *ArgBegin,
+                          const char* const *ArgEnd,
+                          unsigned &MissingArgIndex,
+                          unsigned &MissingArgCount) const;
+
+  /// \brief Render the help text for an option table.
+  ///
+  /// \param OS - The stream to write the help text to.
+  /// \param Name - The name to use in the usage line.
+  /// \param Title - The title to use in the usage line.
+  /// \param ShowHidden - Whether help-hidden arguments should be shown.
+  void PrintHelp(raw_ostream &OS, const char *Name,
+                  const char *Title, bool ShowHidden = false) const;
+};
+} // end namespace opt
+} // end namespace llvm
+
+#endif