1 //===- Option.h - Abstract Driver Options -----------------------*- 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 #ifndef LLVM_OPTION_OPTION_H
10 #define LLVM_OPTION_OPTION_H
11 
12 #include "llvm/ADT/SmallVector.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/Option/OptSpecifier.h"
15 #include "llvm/Option/OptTable.h"
16 #include "llvm/Support/ErrorHandling.h"
17 #include <cassert>
18 #include <string>
19 
20 namespace llvm {
21 
22 class raw_ostream;
23 
24 namespace opt {
25 
26 class Arg;
27 class ArgList;
28 
29 /// ArgStringList - Type used for constructing argv lists for subprocesses.
30 using ArgStringList = SmallVector<const char *, 16>;
31 
32 /// Base flags for all options. Custom flags may be added after.
33 enum DriverFlag {
34   HelpHidden       = (1 << 0),
35   RenderAsInput    = (1 << 1),
36   RenderJoined     = (1 << 2),
37   RenderSeparate   = (1 << 3)
38 };
39 
40 /// Option - Abstract representation for a single form of driver
41 /// argument.
42 ///
43 /// An Option class represents a form of option that the driver
44 /// takes, for example how many arguments the option has and how
45 /// they can be provided. Individual option instances store
46 /// additional information about what group the option is a member
47 /// of (if any), if the option is an alias, and a number of
48 /// flags. At runtime the driver parses the command line into
49 /// concrete Arg instances, each of which corresponds to a
50 /// particular Option instance.
51 class Option {
52 public:
53   enum OptionClass {
54     GroupClass = 0,
55     InputClass,
56     UnknownClass,
57     FlagClass,
58     JoinedClass,
59     ValuesClass,
60     SeparateClass,
61     RemainingArgsClass,
62     RemainingArgsJoinedClass,
63     CommaJoinedClass,
64     MultiArgClass,
65     JoinedOrSeparateClass,
66     JoinedAndSeparateClass
67   };
68 
69   enum RenderStyleKind {
70     RenderCommaJoinedStyle,
71     RenderJoinedStyle,
72     RenderSeparateStyle,
73     RenderValuesStyle
74   };
75 
76 protected:
77   const OptTable::Info *Info;
78   const OptTable *Owner;
79 
80 public:
81   Option(const OptTable::Info *Info, const OptTable *Owner);
82 
83   bool isValid() const {
84     return Info != nullptr;
85   }
86 
87   unsigned getID() const {
88     assert(Info && "Must have a valid info!");
89     return Info->ID;
90   }
91 
92   OptionClass getKind() const {
93     assert(Info && "Must have a valid info!");
94     return OptionClass(Info->Kind);
95   }
96 
97   /// Get the name of this option without any prefix.
98   StringRef getName() const {
99     assert(Info && "Must have a valid info!");
100     return Info->Name;
101   }
102 
103   const Option getGroup() const {
104     assert(Info && "Must have a valid info!");
105     assert(Owner && "Must have a valid owner!");
106     return Owner->getOption(Info->GroupID);
107   }
108 
109   const Option getAlias() const {
110     assert(Info && "Must have a valid info!");
111     assert(Owner && "Must have a valid owner!");
112     return Owner->getOption(Info->AliasID);
113   }
114 
115   /// Get the alias arguments as a \0 separated list.
116   /// E.g. ["foo", "bar"] would be returned as "foo\0bar\0".
117   const char *getAliasArgs() const {
118     assert(Info && "Must have a valid info!");
119     assert((!Info->AliasArgs || Info->AliasArgs[0] != 0) &&
120            "AliasArgs should be either 0 or non-empty.");
121 
122     return Info->AliasArgs;
123   }
124 
125   /// Get the default prefix for this option.
126   StringRef getPrefix() const {
127     const char *Prefix = *Info->Prefixes;
128     return Prefix ? Prefix : StringRef();
129   }
130 
131   /// Get the name of this option with the default prefix.
132   std::string getPrefixedName() const {
133     std::string Ret(getPrefix());
134     Ret += getName();
135     return Ret;
136   }
137 
138   /// Get the help text for this option.
139   StringRef getHelpText() const {
140     assert(Info && "Must have a valid info!");
141     return Info->HelpText;
142   }
143 
144   /// Get the meta-variable list for this option.
145   StringRef getMetaVar() const {
146     assert(Info && "Must have a valid info!");
147     return Info->MetaVar;
148   }
149 
150   unsigned getNumArgs() const { return Info->Param; }
151 
152   bool hasNoOptAsInput() const { return Info->Flags & RenderAsInput;}
153 
154   RenderStyleKind getRenderStyle() const {
155     if (Info->Flags & RenderJoined)
156       return RenderJoinedStyle;
157     if (Info->Flags & RenderSeparate)
158       return RenderSeparateStyle;
159     switch (getKind()) {
160     case GroupClass:
161     case InputClass:
162     case UnknownClass:
163       return RenderValuesStyle;
164     case JoinedClass:
165     case JoinedAndSeparateClass:
166       return RenderJoinedStyle;
167     case CommaJoinedClass:
168       return RenderCommaJoinedStyle;
169     case FlagClass:
170     case ValuesClass:
171     case SeparateClass:
172     case MultiArgClass:
173     case JoinedOrSeparateClass:
174     case RemainingArgsClass:
175     case RemainingArgsJoinedClass:
176       return RenderSeparateStyle;
177     }
178     llvm_unreachable("Unexpected kind!");
179   }
180 
181   /// Test if this option has the flag \a Val.
182   bool hasFlag(unsigned Val) const {
183     return Info->Flags & Val;
184   }
185 
186   /// getUnaliasedOption - Return the final option this option
187   /// aliases (itself, if the option has no alias).
188   const Option getUnaliasedOption() const {
189     const Option Alias = getAlias();
190     if (Alias.isValid()) return Alias.getUnaliasedOption();
191     return *this;
192   }
193 
194   /// getRenderName - Return the name to use when rendering this
195   /// option.
196   StringRef getRenderName() const {
197     return getUnaliasedOption().getName();
198   }
199 
200   /// matches - Predicate for whether this option is part of the
201   /// given option (which may be a group).
202   ///
203   /// Note that matches against options which are an alias should never be
204   /// done -- aliases do not participate in matching and so such a query will
205   /// always be false.
206   bool matches(OptSpecifier ID) const;
207 
208   /// accept - Potentially accept the current argument, returning a
209   /// new Arg instance, or 0 if the option does not accept this
210   /// argument (or the argument is missing values).
211   ///
212   /// If the option accepts the current argument, accept() sets
213   /// Index to the position where argument parsing should resume
214   /// (even if the argument is missing values).
215   ///
216   /// \p CurArg The argument to be matched. It may be shorter than the
217   /// underlying storage to represent a Joined argument.
218   /// \p GroupedShortOption If true, we are handling the fallback case of
219   /// parsing a prefix of the current argument as a short option.
220   Arg *accept(const ArgList &Args, StringRef CurArg, bool GroupedShortOption,
221               unsigned &Index) const;
222 
223 private:
224   Arg *acceptInternal(const ArgList &Args, StringRef CurArg,
225                       unsigned &Index) const;
226 
227 public:
228   void print(raw_ostream &O) const;
229   void dump() const;
230 };
231 
232 } // end namespace opt
233 
234 } // end namespace llvm
235 
236 #endif // LLVM_OPTION_OPTION_H
237