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     return llvm::is_contained(Values, Value);
122   }
123 
124   /// Append the argument onto the given array as strings.
125   void render(const ArgList &Args, ArgStringList &Output) const;
126 
127   /// Append the argument, render as an input, onto the given
128   /// array as strings.
129   ///
130   /// The distinction is that some options only render their values
131   /// when rendered as a input (e.g., Xlinker).
132   void renderAsInput(const ArgList &Args, ArgStringList &Output) const;
133 
134   void print(raw_ostream &O) const;
135   void dump() const;
136 
137   /// Return a formatted version of the argument and its values, for
138   /// diagnostics. Since this is for diagnostics, if this Arg was produced
139   /// through an alias, this returns the string representation of the alias
140   /// that the user wrote.
141   std::string getAsString(const ArgList &Args) const;
142 };
143 
144 } // end namespace opt
145 
146 } // end namespace llvm
147 
148 #endif // LLVM_OPTION_ARG_H
149