1 //===- Option.cpp - Abstract Driver Options -------------------------------===//
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 #include "llvm/ADT/StringRef.h"
10 #include "llvm/ADT/Twine.h"
11 #include "llvm/Config/llvm-config.h"
12 #include "llvm/Option/Arg.h"
13 #include "llvm/Option/ArgList.h"
14 #include "llvm/Option/Option.h"
15 #include "llvm/Option/OptTable.h"
16 #include "llvm/Support/Compiler.h"
17 #include "llvm/Support/Debug.h"
18 #include "llvm/Support/ErrorHandling.h"
19 #include "llvm/Support/raw_ostream.h"
20 #include <cassert>
21 #include <cstring>
22 
23 using namespace llvm;
24 using namespace llvm::opt;
25 
26 Option::Option(const OptTable::Info *info, const OptTable *owner)
27   : Info(info), Owner(owner) {
28   // Multi-level aliases are not supported. This just simplifies option
29   // tracking, it is not an inherent limitation.
30   assert((!Info || !getAlias().isValid() || !getAlias().getAlias().isValid()) &&
31          "Multi-level aliases are not supported.");
32 
33   if (Info && getAliasArgs()) {
34     assert(getAlias().isValid() && "Only alias options can have alias args.");
35     assert(getKind() == FlagClass && "Only Flag aliases can have alias args.");
36     assert(getAlias().getKind() != FlagClass &&
37            "Cannot provide alias args to a flag option.");
38   }
39 }
40 
41 void Option::print(raw_ostream &O) const {
42   O << "<";
43   switch (getKind()) {
44 #define P(N) case N: O << #N; break
45     P(GroupClass);
46     P(InputClass);
47     P(UnknownClass);
48     P(FlagClass);
49     P(JoinedClass);
50     P(ValuesClass);
51     P(SeparateClass);
52     P(CommaJoinedClass);
53     P(MultiArgClass);
54     P(JoinedOrSeparateClass);
55     P(JoinedAndSeparateClass);
56     P(RemainingArgsClass);
57     P(RemainingArgsJoinedClass);
58 #undef P
59   }
60 
61   if (!Info->Prefixes.empty()) {
62     O << " Prefixes:[";
63     for (size_t I = 0, N = Info->Prefixes.size(); I != N; ++I)
64       O << '"' << Info->Prefixes[I] << (I == N - 1 ? "\"" : "\", ");
65     O << ']';
66   }
67 
68   O << " Name:\"" << getName() << '"';
69 
70   const Option Group = getGroup();
71   if (Group.isValid()) {
72     O << " Group:";
73     Group.print(O);
74   }
75 
76   const Option Alias = getAlias();
77   if (Alias.isValid()) {
78     O << " Alias:";
79     Alias.print(O);
80   }
81 
82   if (getKind() == MultiArgClass)
83     O << " NumArgs:" << getNumArgs();
84 
85   O << ">\n";
86 }
87 
88 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
89 LLVM_DUMP_METHOD void Option::dump() const { print(dbgs()); }
90 #endif
91 
92 bool Option::matches(OptSpecifier Opt) const {
93   // Aliases are never considered in matching, look through them.
94   const Option Alias = getAlias();
95   if (Alias.isValid())
96     return Alias.matches(Opt);
97 
98   // Check exact match.
99   if (getID() == Opt.getID())
100     return true;
101 
102   const Option Group = getGroup();
103   if (Group.isValid())
104     return Group.matches(Opt);
105   return false;
106 }
107 
108 std::unique_ptr<Arg> Option::acceptInternal(const ArgList &Args,
109                                             StringRef Spelling,
110                                             unsigned &Index) const {
111   const size_t SpellingSize = Spelling.size();
112   const size_t ArgStringSize = StringRef(Args.getArgString(Index)).size();
113   switch (getKind()) {
114   case FlagClass: {
115     if (SpellingSize != ArgStringSize)
116       return nullptr;
117     return std::make_unique<Arg>(*this, Spelling, Index++);
118   }
119   case JoinedClass: {
120     const char *Value = Args.getArgString(Index) + SpellingSize;
121     return std::make_unique<Arg>(*this, Spelling, Index++, Value);
122   }
123   case CommaJoinedClass: {
124     // Always matches.
125     const char *Str = Args.getArgString(Index) + SpellingSize;
126     auto A = std::make_unique<Arg>(*this, Spelling, Index++);
127 
128     // Parse out the comma separated values.
129     const char *Prev = Str;
130     for (;; ++Str) {
131       char c = *Str;
132 
133       if (!c || c == ',') {
134         if (Prev != Str) {
135           char *Value = new char[Str - Prev + 1];
136           memcpy(Value, Prev, Str - Prev);
137           Value[Str - Prev] = '\0';
138           A->getValues().push_back(Value);
139         }
140 
141         if (!c)
142           break;
143 
144         Prev = Str + 1;
145       }
146     }
147     A->setOwnsValues(true);
148 
149     return A;
150   }
151   case SeparateClass:
152     // Matches iff this is an exact match.
153     if (SpellingSize != ArgStringSize)
154       return nullptr;
155 
156     Index += 2;
157     if (Index > Args.getNumInputArgStrings() ||
158         Args.getArgString(Index - 1) == nullptr)
159       return nullptr;
160 
161     return std::make_unique<Arg>(*this, Spelling, Index - 2,
162                                  Args.getArgString(Index - 1));
163   case MultiArgClass: {
164     // Matches iff this is an exact match.
165     if (SpellingSize != ArgStringSize)
166       return nullptr;
167 
168     Index += 1 + getNumArgs();
169     if (Index > Args.getNumInputArgStrings())
170       return nullptr;
171 
172     auto A = std::make_unique<Arg>(*this, Spelling, Index - 1 - getNumArgs(),
173                                    Args.getArgString(Index - getNumArgs()));
174     for (unsigned i = 1; i != getNumArgs(); ++i)
175       A->getValues().push_back(Args.getArgString(Index - getNumArgs() + i));
176     return A;
177   }
178   case JoinedOrSeparateClass: {
179     // If this is not an exact match, it is a joined arg.
180     if (SpellingSize != ArgStringSize) {
181       const char *Value = Args.getArgString(Index) + SpellingSize;
182       return std::make_unique<Arg>(*this, Spelling, Index++, Value);
183     }
184 
185     // Otherwise it must be separate.
186     Index += 2;
187     if (Index > Args.getNumInputArgStrings() ||
188         Args.getArgString(Index - 1) == nullptr)
189       return nullptr;
190 
191     return std::make_unique<Arg>(*this, Spelling, Index - 2,
192                                  Args.getArgString(Index - 1));
193   }
194   case JoinedAndSeparateClass:
195     // Always matches.
196     Index += 2;
197     if (Index > Args.getNumInputArgStrings() ||
198         Args.getArgString(Index - 1) == nullptr)
199       return nullptr;
200 
201     return std::make_unique<Arg>(*this, Spelling, Index - 2,
202                                  Args.getArgString(Index - 2) + SpellingSize,
203                                  Args.getArgString(Index - 1));
204   case RemainingArgsClass: {
205     // Matches iff this is an exact match.
206     if (SpellingSize != ArgStringSize)
207       return nullptr;
208     auto A = std::make_unique<Arg>(*this, Spelling, Index++);
209     while (Index < Args.getNumInputArgStrings() &&
210            Args.getArgString(Index) != nullptr)
211       A->getValues().push_back(Args.getArgString(Index++));
212     return A;
213   }
214   case RemainingArgsJoinedClass: {
215     auto A = std::make_unique<Arg>(*this, Spelling, Index);
216     if (SpellingSize != ArgStringSize) {
217       // An inexact match means there is a joined arg.
218       A->getValues().push_back(Args.getArgString(Index) + SpellingSize);
219     }
220     Index++;
221     while (Index < Args.getNumInputArgStrings() &&
222            Args.getArgString(Index) != nullptr)
223       A->getValues().push_back(Args.getArgString(Index++));
224     return A;
225   }
226 
227   default:
228     llvm_unreachable("Invalid option kind!");
229   }
230 }
231 
232 std::unique_ptr<Arg> Option::accept(const ArgList &Args, StringRef CurArg,
233                                     bool GroupedShortOption,
234                                     unsigned &Index) const {
235   auto A(GroupedShortOption && getKind() == FlagClass
236                              ? std::make_unique<Arg>(*this, CurArg, Index)
237                              : acceptInternal(Args, CurArg, Index));
238   if (!A)
239     return nullptr;
240 
241   const Option &UnaliasedOption = getUnaliasedOption();
242   if (getID() == UnaliasedOption.getID())
243     return A;
244 
245   // "A" is an alias for a different flag. For most clients it's more convenient
246   // if this function returns unaliased Args, so create an unaliased arg for
247   // returning.
248 
249   // This creates a completely new Arg object for the unaliased Arg because
250   // the alias and the unaliased arg can have different Kinds and different
251   // Values (due to AliasArgs<>).
252 
253   // Get the spelling from the unaliased option.
254   StringRef UnaliasedSpelling = Args.MakeArgString(
255       Twine(UnaliasedOption.getPrefix()) + Twine(UnaliasedOption.getName()));
256 
257   // It's a bit weird that aliased and unaliased arg share one index, but
258   // the index is mostly use as a memory optimization in render().
259   // Due to this, ArgList::getArgString(A->getIndex()) will return the spelling
260   // of the aliased arg always, while A->getSpelling() returns either the
261   // unaliased or the aliased arg, depending on which Arg object it's called on.
262   auto UnaliasedA =
263       std::make_unique<Arg>(UnaliasedOption, UnaliasedSpelling, A->getIndex());
264   Arg *RawA = A.get();
265   UnaliasedA->setAlias(std::move(A));
266 
267   if (getKind() != FlagClass) {
268     // Values are usually owned by the ArgList. The exception are
269     // CommaJoined flags, where the Arg owns the values. For aliased flags,
270     // make the unaliased Arg the owner of the values.
271     // FIXME: There aren't many uses of CommaJoined -- try removing
272     // CommaJoined in favor of just calling StringRef::split(',') instead.
273     UnaliasedA->getValues() = RawA->getValues();
274     UnaliasedA->setOwnsValues(RawA->getOwnsValues());
275     RawA->setOwnsValues(false);
276     return UnaliasedA;
277   }
278 
279   // FlagClass aliases can have AliasArgs<>; add those to the unaliased arg.
280   if (const char *Val = getAliasArgs()) {
281     while (*Val != '\0') {
282       UnaliasedA->getValues().push_back(Val);
283 
284       // Move past the '\0' to the next argument.
285       Val += strlen(Val) + 1;
286     }
287   }
288   if (UnaliasedOption.getKind() == JoinedClass && !getAliasArgs())
289     // A Flag alias for a Joined option must provide an argument.
290     UnaliasedA->getValues().push_back("");
291   return UnaliasedA;
292 }
293