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 affect compilation?
51   ///
52   /// This is used to generate an "argument unused" warning (without
53   /// clang::driver::options::TargetSpecific) or "unsupported option" error
54   /// (with TargetSpecific).
55   mutable unsigned Claimed : 1;
56 
57   /// Used by an unclaimed option with the TargetSpecific flag. If set, report
58   /// an "argument unused" warning instead of an "unsupported option" error.
59   unsigned IgnoredTargetSpecific : 1;
60 
61   /// Does this argument own its values?
62   mutable unsigned OwnsValues : 1;
63 
64   /// The argument values, as C strings.
65   SmallVector<const char *, 2> Values;
66 
67   /// If this arg was created through an alias, this is the original alias arg.
68   /// For example, *this might be "-finput-charset=utf-8" and Alias might
69   /// point to an arg representing "/source-charset:utf-8".
70   std::unique_ptr<Arg> Alias;
71 
72 public:
73   Arg(const Option Opt, StringRef Spelling, unsigned Index,
74       const Arg *BaseArg = nullptr);
75   Arg(const Option Opt, StringRef Spelling, unsigned Index,
76       const char *Value0, const Arg *BaseArg = nullptr);
77   Arg(const Option Opt, StringRef Spelling, unsigned Index,
78       const char *Value0, const char *Value1, const Arg *BaseArg = nullptr);
79   Arg(const Arg &) = delete;
80   Arg &operator=(const Arg &) = delete;
81   ~Arg();
82 
83   const Option &getOption() const { return Opt; }
84 
85   /// Returns the used prefix and name of the option:
86   /// For `--foo=bar`, returns `--foo=`.
87   /// This is often the wrong function to call:
88   /// * Use `getValue()` to get `bar`.
89   /// * Use `getAsString()` to get a string suitable for printing an Arg in
90   ///   a diagnostic.
91   StringRef getSpelling() const { return Spelling; }
92 
93   unsigned getIndex() const { return Index; }
94 
95   /// Return the base argument which generated this arg.
96   ///
97   /// This is either the argument itself or the argument it was
98   /// derived from during tool chain specific argument translation.
99   const Arg &getBaseArg() const {
100     return BaseArg ? *BaseArg : *this;
101   }
102   Arg &getBaseArg() { return BaseArg ? const_cast<Arg &>(*BaseArg) : *this; }
103   void setBaseArg(const Arg *BaseArg) { this->BaseArg = BaseArg; }
104 
105   /// Args are converted to their unaliased form.  For args that originally
106   /// came from an alias, this returns the alias the arg was produced from.
107   const Arg* getAlias() const { return Alias.get(); }
108   void setAlias(std::unique_ptr<Arg> Alias) { this->Alias = std::move(Alias); }
109 
110   bool getOwnsValues() const { return OwnsValues; }
111   void setOwnsValues(bool Value) const { OwnsValues = Value; }
112 
113   bool isClaimed() const { return getBaseArg().Claimed; }
114   void claim() const { getBaseArg().Claimed = true; }
115 
116   bool isIgnoredTargetSpecific() const {
117     return getBaseArg().IgnoredTargetSpecific;
118   }
119   void ignoreTargetSpecific() {
120     getBaseArg().IgnoredTargetSpecific = true;
121   }
122 
123   unsigned getNumValues() const { return Values.size(); }
124 
125   const char *getValue(unsigned N = 0) const {
126     return Values[N];
127   }
128 
129   SmallVectorImpl<const char *> &getValues() { return Values; }
130   const SmallVectorImpl<const char *> &getValues() const { return Values; }
131 
132   bool containsValue(StringRef Value) const {
133     return llvm::is_contained(Values, Value);
134   }
135 
136   /// Append the argument onto the given array as strings.
137   void render(const ArgList &Args, ArgStringList &Output) const;
138 
139   /// Append the argument, render as an input, onto the given
140   /// array as strings.
141   ///
142   /// The distinction is that some options only render their values
143   /// when rendered as a input (e.g., Xlinker).
144   void renderAsInput(const ArgList &Args, ArgStringList &Output) const;
145 
146   void print(raw_ostream &O) const;
147   void dump() const;
148 
149   /// Return a formatted version of the argument and its values, for
150   /// diagnostics. Since this is for diagnostics, if this Arg was produced
151   /// through an alias, this returns the string representation of the alias
152   /// that the user wrote.
153   std::string getAsString(const ArgList &Args) const;
154 };
155 
156 } // end namespace opt
157 
158 } // end namespace llvm
159 
160 #endif // LLVM_OPTION_ARG_H
161