1 | //===--- VariantValue.h - Polymorphic value type ----------------*- 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 | /// Polymorphic value type. |
11 | /// |
12 | /// Supports all the types required for dynamic Matcher construction. |
13 | /// Used by the registry to construct matchers in a generic way. |
14 | /// |
15 | //===----------------------------------------------------------------------===// |
16 | |
17 | #ifndef LLVM_CLANG_ASTMATCHERS_DYNAMIC_VARIANTVALUE_H |
18 | #define LLVM_CLANG_ASTMATCHERS_DYNAMIC_VARIANTVALUE_H |
19 | |
20 | #include "clang/ASTMatchers/ASTMatchers.h" |
21 | #include "clang/ASTMatchers/ASTMatchersInternal.h" |
22 | #include "llvm/ADT/IntrusiveRefCntPtr.h" |
23 | #include <memory> |
24 | #include <optional> |
25 | #include <vector> |
26 | |
27 | namespace clang { |
28 | namespace ast_matchers { |
29 | namespace dynamic { |
30 | |
31 | /// Kind identifier. |
32 | /// |
33 | /// It supports all types that VariantValue can contain. |
34 | class ArgKind { |
35 | public: |
36 | enum Kind { |
37 | AK_Matcher, |
38 | AK_Node, |
39 | AK_Boolean, |
40 | AK_Double, |
41 | AK_Unsigned, |
42 | AK_String |
43 | }; |
44 | /// Constructor for non-matcher types. |
45 | ArgKind(Kind K) : K(K) { assert(K != AK_Matcher); } |
46 | |
47 | /// Constructor for matcher types. |
48 | static ArgKind MakeMatcherArg(ASTNodeKind MatcherKind) { |
49 | return ArgKind{AK_Matcher, MatcherKind}; |
50 | } |
51 | |
52 | static ArgKind MakeNodeArg(ASTNodeKind MatcherKind) { |
53 | return ArgKind{AK_Node, MatcherKind}; |
54 | } |
55 | |
56 | Kind getArgKind() const { return K; } |
57 | ASTNodeKind getMatcherKind() const { |
58 | assert(K == AK_Matcher); |
59 | return NodeKind; |
60 | } |
61 | ASTNodeKind getNodeKind() const { |
62 | assert(K == AK_Node); |
63 | return NodeKind; |
64 | } |
65 | |
66 | /// Determines if this type can be converted to \p To. |
67 | /// |
68 | /// \param To the requested destination type. |
69 | /// |
70 | /// \param Specificity value corresponding to the "specificity" of the |
71 | /// conversion. |
72 | bool isConvertibleTo(ArgKind To, unsigned *Specificity) const; |
73 | |
74 | bool operator<(const ArgKind &Other) const { |
75 | if ((K == AK_Matcher && Other.K == AK_Matcher) || |
76 | (K == AK_Node && Other.K == AK_Node)) |
77 | return NodeKind < Other.NodeKind; |
78 | return K < Other.K; |
79 | } |
80 | |
81 | /// String representation of the type. |
82 | std::string asString() const; |
83 | |
84 | private: |
85 | ArgKind(Kind K, ASTNodeKind NK) : K(K), NodeKind(NK) {} |
86 | Kind K; |
87 | ASTNodeKind NodeKind; |
88 | }; |
89 | |
90 | using ast_matchers::internal::DynTypedMatcher; |
91 | |
92 | /// A variant matcher object. |
93 | /// |
94 | /// The purpose of this object is to abstract simple and polymorphic matchers |
95 | /// into a single object type. |
96 | /// Polymorphic matchers might be implemented as a list of all the possible |
97 | /// overloads of the matcher. \c VariantMatcher knows how to select the |
98 | /// appropriate overload when needed. |
99 | /// To get a real matcher object out of a \c VariantMatcher you can do: |
100 | /// - getSingleMatcher() which returns a matcher, only if it is not ambiguous |
101 | /// to decide which matcher to return. Eg. it contains only a single |
102 | /// matcher, or a polymorphic one with only one overload. |
103 | /// - hasTypedMatcher<T>()/getTypedMatcher<T>(): These calls will determine if |
104 | /// the underlying matcher(s) can unambiguously return a Matcher<T>. |
105 | class VariantMatcher { |
106 | /// Methods that depend on T from hasTypedMatcher/getTypedMatcher. |
107 | class MatcherOps { |
108 | public: |
109 | MatcherOps(ASTNodeKind NodeKind) : NodeKind(NodeKind) {} |
110 | |
111 | bool canConstructFrom(const DynTypedMatcher &Matcher, |
112 | bool &IsExactMatch) const; |
113 | |
114 | /// Convert \p Matcher the destination type and return it as a new |
115 | /// DynTypedMatcher. |
116 | DynTypedMatcher convertMatcher(const DynTypedMatcher &Matcher) const; |
117 | |
118 | /// Constructs a variadic typed matcher from \p InnerMatchers. |
119 | /// Will try to convert each inner matcher to the destination type and |
120 | /// return std::nullopt if it fails to do so. |
121 | std::optional<DynTypedMatcher> |
122 | constructVariadicOperator(DynTypedMatcher::VariadicOperator Op, |
123 | ArrayRef<VariantMatcher> InnerMatchers) const; |
124 | |
125 | private: |
126 | ASTNodeKind NodeKind; |
127 | }; |
128 | |
129 | /// Payload interface to be specialized by each matcher type. |
130 | /// |
131 | /// It follows a similar interface as VariantMatcher itself. |
132 | class Payload { |
133 | public: |
134 | virtual ~Payload(); |
135 | virtual std::optional<DynTypedMatcher> getSingleMatcher() const = 0; |
136 | virtual std::string getTypeAsString() const = 0; |
137 | virtual std::optional<DynTypedMatcher> |
138 | getTypedMatcher(const MatcherOps &Ops) const = 0; |
139 | virtual bool isConvertibleTo(ASTNodeKind Kind, |
140 | unsigned *Specificity) const = 0; |
141 | }; |
142 | |
143 | public: |
144 | /// A null matcher. |
145 | VariantMatcher(); |
146 | |
147 | /// Clones the provided matcher. |
148 | static VariantMatcher SingleMatcher(const DynTypedMatcher &Matcher); |
149 | |
150 | /// Clones the provided matchers. |
151 | /// |
152 | /// They should be the result of a polymorphic matcher. |
153 | static VariantMatcher |
154 | PolymorphicMatcher(std::vector<DynTypedMatcher> Matchers); |
155 | |
156 | /// Creates a 'variadic' operator matcher. |
157 | /// |
158 | /// It will bind to the appropriate type on getTypedMatcher<T>(). |
159 | static VariantMatcher |
160 | VariadicOperatorMatcher(DynTypedMatcher::VariadicOperator Op, |
161 | std::vector<VariantMatcher> Args); |
162 | |
163 | /// Makes the matcher the "null" matcher. |
164 | void reset(); |
165 | |
166 | /// Whether the matcher is null. |
167 | bool isNull() const { return !Value; } |
168 | |
169 | /// Return a single matcher, if there is no ambiguity. |
170 | /// |
171 | /// \returns the matcher, if there is only one matcher. An empty Optional, if |
172 | /// the underlying matcher is a polymorphic matcher with more than one |
173 | /// representation. |
174 | std::optional<DynTypedMatcher> getSingleMatcher() const; |
175 | |
176 | /// Determines if the contained matcher can be converted to |
177 | /// \c Matcher<T>. |
178 | /// |
179 | /// For the Single case, it returns true if it can be converted to |
180 | /// \c Matcher<T>. |
181 | /// For the Polymorphic case, it returns true if one, and only one, of the |
182 | /// overloads can be converted to \c Matcher<T>. If there are more than one |
183 | /// that can, the result would be ambiguous and false is returned. |
184 | template <class T> |
185 | bool hasTypedMatcher() const { |
186 | return hasTypedMatcher(ASTNodeKind::getFromNodeKind<T>()); |
187 | } |
188 | |
189 | bool hasTypedMatcher(ASTNodeKind NK) const { |
190 | if (!Value) return false; |
191 | return Value->getTypedMatcher(Ops: MatcherOps(NK)).has_value(); |
192 | } |
193 | |
194 | /// Determines if the contained matcher can be converted to \p Kind. |
195 | /// |
196 | /// \param Kind the requested destination type. |
197 | /// |
198 | /// \param Specificity value corresponding to the "specificity" of the |
199 | /// conversion. |
200 | bool isConvertibleTo(ASTNodeKind Kind, unsigned *Specificity) const { |
201 | if (Value) |
202 | return Value->isConvertibleTo(Kind, Specificity); |
203 | return false; |
204 | } |
205 | |
206 | /// Return this matcher as a \c Matcher<T>. |
207 | /// |
208 | /// Handles the different types (Single, Polymorphic) accordingly. |
209 | /// Asserts that \c hasTypedMatcher<T>() is true. |
210 | template <class T> |
211 | ast_matchers::internal::Matcher<T> getTypedMatcher() const { |
212 | assert(hasTypedMatcher<T>() && "hasTypedMatcher<T>() == false" ); |
213 | return Value->getTypedMatcher(Ops: MatcherOps(ASTNodeKind::getFromNodeKind<T>())) |
214 | ->template convertTo<T>(); |
215 | } |
216 | |
217 | DynTypedMatcher getTypedMatcher(ASTNodeKind NK) const { |
218 | assert(hasTypedMatcher(NK) && "hasTypedMatcher(NK) == false" ); |
219 | return *Value->getTypedMatcher(Ops: MatcherOps(NK)); |
220 | } |
221 | |
222 | /// String representation of the type of the value. |
223 | /// |
224 | /// If the underlying matcher is a polymorphic one, the string will show all |
225 | /// the types. |
226 | std::string getTypeAsString() const; |
227 | |
228 | private: |
229 | explicit VariantMatcher(std::shared_ptr<Payload> Value) |
230 | : Value(std::move(Value)) {} |
231 | |
232 | |
233 | class SinglePayload; |
234 | class PolymorphicPayload; |
235 | class VariadicOpPayload; |
236 | |
237 | std::shared_ptr<const Payload> Value; |
238 | }; |
239 | |
240 | /// Variant value class. |
241 | /// |
242 | /// Basically, a tagged union with value type semantics. |
243 | /// It is used by the registry as the return value and argument type for the |
244 | /// matcher factory methods. |
245 | /// It can be constructed from any of the supported types. It supports |
246 | /// copy/assignment. |
247 | /// |
248 | /// Supported types: |
249 | /// - \c bool |
250 | // - \c double |
251 | /// - \c unsigned |
252 | /// - \c llvm::StringRef |
253 | /// - \c VariantMatcher (\c DynTypedMatcher / \c Matcher<T>) |
254 | class VariantValue { |
255 | public: |
256 | VariantValue() : Type(VT_Nothing) {} |
257 | |
258 | VariantValue(const VariantValue &Other); |
259 | ~VariantValue(); |
260 | VariantValue &operator=(const VariantValue &Other); |
261 | |
262 | /// Specific constructors for each supported type. |
263 | VariantValue(bool Boolean); |
264 | VariantValue(double Double); |
265 | VariantValue(unsigned Unsigned); |
266 | VariantValue(StringRef String); |
267 | VariantValue(ASTNodeKind NodeKind); |
268 | VariantValue(const VariantMatcher &Matchers); |
269 | |
270 | /// Constructs an \c unsigned value (disambiguation from bool). |
271 | VariantValue(int Signed) : VariantValue(static_cast<unsigned>(Signed)) {} |
272 | |
273 | /// Returns true iff this is not an empty value. |
274 | explicit operator bool() const { return hasValue(); } |
275 | bool hasValue() const { return Type != VT_Nothing; } |
276 | |
277 | /// Boolean value functions. |
278 | bool isBoolean() const; |
279 | bool getBoolean() const; |
280 | void setBoolean(bool Boolean); |
281 | |
282 | /// Double value functions. |
283 | bool isDouble() const; |
284 | double getDouble() const; |
285 | void setDouble(double Double); |
286 | |
287 | /// Unsigned value functions. |
288 | bool isUnsigned() const; |
289 | unsigned getUnsigned() const; |
290 | void setUnsigned(unsigned Unsigned); |
291 | |
292 | /// String value functions. |
293 | bool isString() const; |
294 | const std::string &getString() const; |
295 | void setString(StringRef String); |
296 | |
297 | bool isNodeKind() const; |
298 | const ASTNodeKind &getNodeKind() const; |
299 | void setNodeKind(ASTNodeKind NodeKind); |
300 | |
301 | /// Matcher value functions. |
302 | bool isMatcher() const; |
303 | const VariantMatcher &getMatcher() const; |
304 | void setMatcher(const VariantMatcher &Matcher); |
305 | |
306 | /// Determines if the contained value can be converted to \p Kind. |
307 | /// |
308 | /// \param Kind the requested destination type. |
309 | /// |
310 | /// \param Specificity value corresponding to the "specificity" of the |
311 | /// conversion. |
312 | bool isConvertibleTo(ArgKind Kind, unsigned* Specificity) const; |
313 | |
314 | /// Determines if the contained value can be converted to any kind |
315 | /// in \p Kinds. |
316 | /// |
317 | /// \param Kinds the requested destination types. |
318 | /// |
319 | /// \param Specificity value corresponding to the "specificity" of the |
320 | /// conversion. It is the maximum specificity of all the possible |
321 | /// conversions. |
322 | bool isConvertibleTo(ArrayRef<ArgKind> Kinds, unsigned *Specificity) const; |
323 | |
324 | /// String representation of the type of the value. |
325 | std::string getTypeAsString() const; |
326 | |
327 | private: |
328 | void reset(); |
329 | |
330 | /// All supported value types. |
331 | enum ValueType { |
332 | VT_Nothing, |
333 | VT_Boolean, |
334 | VT_Double, |
335 | VT_Unsigned, |
336 | VT_String, |
337 | VT_Matcher, |
338 | VT_NodeKind |
339 | }; |
340 | |
341 | /// All supported value types. |
342 | union AllValues { |
343 | unsigned Unsigned; |
344 | double Double; |
345 | bool Boolean; |
346 | std::string *String; |
347 | VariantMatcher *Matcher; |
348 | ASTNodeKind *NodeKind; |
349 | }; |
350 | |
351 | ValueType Type; |
352 | AllValues Value; |
353 | }; |
354 | |
355 | } // end namespace dynamic |
356 | } // end namespace ast_matchers |
357 | } // end namespace clang |
358 | |
359 | #endif // LLVM_CLANG_ASTMATCHERS_DYNAMIC_VARIANTVALUE_H |
360 | |