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      1 //===- Arg.h - Parsed Argument Classes --------------------------*- C++ -*-===//
      2 //
      3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
      4 // See https://llvm.org/LICENSE.txt for license information.
      5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
      6 //
      7 //===----------------------------------------------------------------------===//
      8 ///
      9 /// \file
     10 /// Defines the llvm::Arg class for parsed arguments.
     11 ///
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_OPTION_ARG_H
     15 #define LLVM_OPTION_ARG_H
     16 
     17 #include "llvm/ADT/SmallVector.h"
     18 #include "llvm/ADT/StringRef.h"
     19 #include "llvm/Option/Option.h"
     20 #include <string>
     21 
     22 namespace llvm {
     23 
     24 class raw_ostream;
     25 
     26 namespace opt {
     27 
     28 class ArgList;
     29 
     30 /// A concrete instance of a particular driver option.
     31 ///
     32 /// The Arg class encodes just enough information to be able to
     33 /// derive the argument values efficiently.
     34 class Arg {
     35 private:
     36   /// The option this argument is an instance of.
     37   const Option Opt;
     38 
     39   /// The argument this argument was derived from (during tool chain
     40   /// argument translation), if any.
     41   const Arg *BaseArg;
     42 
     43   /// How this instance of the option was spelled.
     44   StringRef Spelling;
     45 
     46   /// The index at which this argument appears in the containing
     47   /// ArgList.
     48   unsigned Index;
     49 
     50   /// Was this argument used to effect compilation?
     51   ///
     52   /// This is used for generating "argument unused" diagnostics.
     53   mutable unsigned Claimed : 1;
     54 
     55   /// Does this argument own its values?
     56   mutable unsigned OwnsValues : 1;
     57 
     58   /// The argument values, as C strings.
     59   SmallVector<const char *, 2> Values;
     60 
     61   /// If this arg was created through an alias, this is the original alias arg.
     62   /// For example, *this might be "-finput-charset=utf-8" and Alias might
     63   /// point to an arg representing "/source-charset:utf-8".
     64   std::unique_ptr<Arg> Alias;
     65 
     66 public:
     67   Arg(const Option Opt, StringRef Spelling, unsigned Index,
     68       const Arg *BaseArg = nullptr);
     69   Arg(const Option Opt, StringRef Spelling, unsigned Index,
     70       const char *Value0, const Arg *BaseArg = nullptr);
     71   Arg(const Option Opt, StringRef Spelling, unsigned Index,
     72       const char *Value0, const char *Value1, const Arg *BaseArg = nullptr);
     73   Arg(const Arg &) = delete;
     74   Arg &operator=(const Arg &) = delete;
     75   ~Arg();
     76 
     77   const Option &getOption() const { return Opt; }
     78 
     79   /// Returns the used prefix and name of the option:
     80   /// For `--foo=bar`, returns `--foo=`.
     81   /// This is often the wrong function to call:
     82   /// * Use `getValue()` to get `bar`.
     83   /// * Use `getAsString()` to get a string suitable for printing an Arg in
     84   ///   a diagnostic.
     85   StringRef getSpelling() const { return Spelling; }
     86 
     87   unsigned getIndex() const { return Index; }
     88 
     89   /// Return the base argument which generated this arg.
     90   ///
     91   /// This is either the argument itself or the argument it was
     92   /// derived from during tool chain specific argument translation.
     93   const Arg &getBaseArg() const {
     94     return BaseArg ? *BaseArg : *this;
     95   }
     96   void setBaseArg(const Arg *BaseArg) { this->BaseArg = BaseArg; }
     97 
     98   /// Args are converted to their unaliased form.  For args that originally
     99   /// came from an alias, this returns the alias the arg was produced from.
    100   const Arg* getAlias() const { return Alias.get(); }
    101   void setAlias(std::unique_ptr<Arg> Alias) { this->Alias = std::move(Alias); }
    102 
    103   bool getOwnsValues() const { return OwnsValues; }
    104   void setOwnsValues(bool Value) const { OwnsValues = Value; }
    105 
    106   bool isClaimed() const { return getBaseArg().Claimed; }
    107 
    108   /// Set the Arg claimed bit.
    109   void claim() const { getBaseArg().Claimed = true; }
    110 
    111   unsigned getNumValues() const { return Values.size(); }
    112 
    113   const char *getValue(unsigned N = 0) const {
    114     return Values[N];
    115   }
    116 
    117   SmallVectorImpl<const char *> &getValues() { return Values; }
    118   const SmallVectorImpl<const char *> &getValues() const { return Values; }
    119 
    120   bool containsValue(StringRef Value) const {
    121     for (unsigned i = 0, e = getNumValues(); i != e; ++i)
    122       if (Values[i] == Value)
    123         return true;
    124     return false;
    125   }
    126 
    127   /// Append the argument onto the given array as strings.
    128   void render(const ArgList &Args, ArgStringList &Output) const;
    129 
    130   /// Append the argument, render as an input, onto the given
    131   /// array as strings.
    132   ///
    133   /// The distinction is that some options only render their values
    134   /// when rendered as a input (e.g., Xlinker).
    135   void renderAsInput(const ArgList &Args, ArgStringList &Output) const;
    136 
    137   void print(raw_ostream &O) const;
    138   void dump() const;
    139 
    140   /// Return a formatted version of the argument and its values, for
    141   /// diagnostics. Since this is for diagnostics, if this Arg was produced
    142   /// through an alias, this returns the string representation of the alias
    143   /// that the user wrote.
    144   std::string getAsString(const ArgList &Args) const;
    145 };
    146 
    147 } // end namespace opt
    148 
    149 } // end namespace llvm
    150 
    151 #endif // LLVM_OPTION_ARG_H
    152