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   size_t ArgSize = Spelling.size();
112   switch (getKind()) {
113   case FlagClass: {
114     if (ArgSize != strlen(Args.getArgString(Index)))
115       return nullptr;
116     return std::make_unique<Arg>(*this, Spelling, Index++);
117   }
118   case JoinedClass: {
119     const char *Value = Args.getArgString(Index) + ArgSize;
120     return std::make_unique<Arg>(*this, Spelling, Index++, Value);
121   }
122   case CommaJoinedClass: {
123     // Always matches.
124     const char *Str = Args.getArgString(Index) + ArgSize;
125     auto A = std::make_unique<Arg>(*this, Spelling, Index++);
126 
127     // Parse out the comma separated values.
128     const char *Prev = Str;
129     for (;; ++Str) {
130       char c = *Str;
131 
132       if (!c || c == ',') {
133         if (Prev != Str) {
134           char *Value = new char[Str - Prev + 1];
135           memcpy(Value, Prev, Str - Prev);
136           Value[Str - Prev] = '\0';
137           A->getValues().push_back(Value);
138         }
139 
140         if (!c)
141           break;
142 
143         Prev = Str + 1;
144       }
145     }
146     A->setOwnsValues(true);
147 
148     return A;
149   }
150   case SeparateClass:
151     // Matches iff this is an exact match.
152     // FIXME: Avoid strlen.
153     if (ArgSize != strlen(Args.getArgString(Index)))
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     // FIXME: Avoid strlen.
166     if (ArgSize != strlen(Args.getArgString(Index)))
167       return nullptr;
168 
169     Index += 1 + getNumArgs();
170     if (Index > Args.getNumInputArgStrings())
171       return nullptr;
172 
173     auto A = std::make_unique<Arg>(*this, Spelling, Index - 1 - getNumArgs(),
174                                    Args.getArgString(Index - getNumArgs()));
175     for (unsigned i = 1; i != getNumArgs(); ++i)
176       A->getValues().push_back(Args.getArgString(Index - getNumArgs() + i));
177     return A;
178   }
179   case JoinedOrSeparateClass: {
180     // If this is not an exact match, it is a joined arg.
181     // FIXME: Avoid strlen.
182     if (ArgSize != strlen(Args.getArgString(Index))) {
183       const char *Value = Args.getArgString(Index) + ArgSize;
184       return std::make_unique<Arg>(*this, Spelling, Index++, Value);
185     }
186 
187     // Otherwise it must be separate.
188     Index += 2;
189     if (Index > Args.getNumInputArgStrings() ||
190         Args.getArgString(Index - 1) == nullptr)
191       return nullptr;
192 
193     return std::make_unique<Arg>(*this, Spelling, Index - 2,
194                                  Args.getArgString(Index - 1));
195   }
196   case JoinedAndSeparateClass:
197     // Always matches.
198     Index += 2;
199     if (Index > Args.getNumInputArgStrings() ||
200         Args.getArgString(Index - 1) == nullptr)
201       return nullptr;
202 
203     return std::make_unique<Arg>(*this, Spelling, Index - 2,
204                                  Args.getArgString(Index - 2) + ArgSize,
205                                  Args.getArgString(Index - 1));
206   case RemainingArgsClass: {
207     // Matches iff this is an exact match.
208     // FIXME: Avoid strlen.
209     if (ArgSize != strlen(Args.getArgString(Index)))
210       return nullptr;
211     auto A = std::make_unique<Arg>(*this, Spelling, Index++);
212     while (Index < Args.getNumInputArgStrings() &&
213            Args.getArgString(Index) != nullptr)
214       A->getValues().push_back(Args.getArgString(Index++));
215     return A;
216   }
217   case RemainingArgsJoinedClass: {
218     auto A = std::make_unique<Arg>(*this, Spelling, Index);
219     if (ArgSize != strlen(Args.getArgString(Index))) {
220       // An inexact match means there is a joined arg.
221       A->getValues().push_back(Args.getArgString(Index) + ArgSize);
222     }
223     Index++;
224     while (Index < Args.getNumInputArgStrings() &&
225            Args.getArgString(Index) != nullptr)
226       A->getValues().push_back(Args.getArgString(Index++));
227     return A;
228   }
229 
230   default:
231     llvm_unreachable("Invalid option kind!");
232   }
233 }
234 
235 std::unique_ptr<Arg> Option::accept(const ArgList &Args, StringRef CurArg,
236                                     bool GroupedShortOption,
237                                     unsigned &Index) const {
238   auto A(GroupedShortOption && getKind() == FlagClass
239                              ? std::make_unique<Arg>(*this, CurArg, Index)
240                              : acceptInternal(Args, CurArg, Index));
241   if (!A)
242     return nullptr;
243 
244   const Option &UnaliasedOption = getUnaliasedOption();
245   if (getID() == UnaliasedOption.getID())
246     return A;
247 
248   // "A" is an alias for a different flag. For most clients it's more convenient
249   // if this function returns unaliased Args, so create an unaliased arg for
250   // returning.
251 
252   // This creates a completely new Arg object for the unaliased Arg because
253   // the alias and the unaliased arg can have different Kinds and different
254   // Values (due to AliasArgs<>).
255 
256   // Get the spelling from the unaliased option.
257   StringRef UnaliasedSpelling = Args.MakeArgString(
258       Twine(UnaliasedOption.getPrefix()) + Twine(UnaliasedOption.getName()));
259 
260   // It's a bit weird that aliased and unaliased arg share one index, but
261   // the index is mostly use as a memory optimization in render().
262   // Due to this, ArgList::getArgString(A->getIndex()) will return the spelling
263   // of the aliased arg always, while A->getSpelling() returns either the
264   // unaliased or the aliased arg, depending on which Arg object it's called on.
265   auto UnaliasedA =
266       std::make_unique<Arg>(UnaliasedOption, UnaliasedSpelling, A->getIndex());
267   Arg *RawA = A.get();
268   UnaliasedA->setAlias(std::move(A));
269 
270   if (getKind() != FlagClass) {
271     // Values are usually owned by the ArgList. The exception are
272     // CommaJoined flags, where the Arg owns the values. For aliased flags,
273     // make the unaliased Arg the owner of the values.
274     // FIXME: There aren't many uses of CommaJoined -- try removing
275     // CommaJoined in favor of just calling StringRef::split(',') instead.
276     UnaliasedA->getValues() = RawA->getValues();
277     UnaliasedA->setOwnsValues(RawA->getOwnsValues());
278     RawA->setOwnsValues(false);
279     return UnaliasedA;
280   }
281 
282   // FlagClass aliases can have AliasArgs<>; add those to the unaliased arg.
283   if (const char *Val = getAliasArgs()) {
284     while (*Val != '\0') {
285       UnaliasedA->getValues().push_back(Val);
286 
287       // Move past the '\0' to the next argument.
288       Val += strlen(Val) + 1;
289     }
290   }
291   if (UnaliasedOption.getKind() == JoinedClass && !getAliasArgs())
292     // A Flag alias for a Joined option must provide an argument.
293     UnaliasedA->getValues().push_back("");
294   return UnaliasedA;
295 }
296