1//===--- ASTMatchersInternal.cpp - Structural query framework -------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  Implements the base layer of the matcher framework.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/ASTMatchers/ASTMatchers.h"
15#include "clang/ASTMatchers/ASTMatchersInternal.h"
16#include "llvm/ADT/SmallString.h"
17#include "llvm/Support/ManagedStatic.h"
18
19namespace clang {
20namespace ast_matchers {
21namespace internal {
22
23bool NotUnaryOperator(const ast_type_traits::DynTypedNode DynNode,
24                      ASTMatchFinder *Finder, BoundNodesTreeBuilder *Builder,
25                      ArrayRef<DynTypedMatcher> InnerMatchers);
26
27bool AllOfVariadicOperator(const ast_type_traits::DynTypedNode DynNode,
28                           ASTMatchFinder *Finder,
29                           BoundNodesTreeBuilder *Builder,
30                           ArrayRef<DynTypedMatcher> InnerMatchers);
31
32bool EachOfVariadicOperator(const ast_type_traits::DynTypedNode DynNode,
33                            ASTMatchFinder *Finder,
34                            BoundNodesTreeBuilder *Builder,
35                            ArrayRef<DynTypedMatcher> InnerMatchers);
36
37bool AnyOfVariadicOperator(const ast_type_traits::DynTypedNode DynNode,
38                           ASTMatchFinder *Finder,
39                           BoundNodesTreeBuilder *Builder,
40                           ArrayRef<DynTypedMatcher> InnerMatchers);
41
42
43void BoundNodesTreeBuilder::visitMatches(Visitor *ResultVisitor) {
44  if (Bindings.empty())
45    Bindings.push_back(BoundNodesMap());
46  for (BoundNodesMap &Binding : Bindings) {
47    ResultVisitor->visitMatch(BoundNodes(Binding));
48  }
49}
50
51namespace {
52
53typedef bool (*VariadicOperatorFunction)(
54    const ast_type_traits::DynTypedNode DynNode, ASTMatchFinder *Finder,
55    BoundNodesTreeBuilder *Builder, ArrayRef<DynTypedMatcher> InnerMatchers);
56
57template <VariadicOperatorFunction Func>
58class VariadicMatcher : public DynMatcherInterface {
59public:
60  VariadicMatcher(std::vector<DynTypedMatcher> InnerMatchers)
61      : InnerMatchers(std::move(InnerMatchers)) {}
62
63  bool dynMatches(const ast_type_traits::DynTypedNode &DynNode,
64                  ASTMatchFinder *Finder,
65                  BoundNodesTreeBuilder *Builder) const override {
66    return Func(DynNode, Finder, Builder, InnerMatchers);
67  }
68
69private:
70  std::vector<DynTypedMatcher> InnerMatchers;
71};
72
73class IdDynMatcher : public DynMatcherInterface {
74 public:
75  IdDynMatcher(StringRef ID,
76               const IntrusiveRefCntPtr<DynMatcherInterface> &InnerMatcher)
77      : ID(ID), InnerMatcher(InnerMatcher) {}
78
79  bool dynMatches(const ast_type_traits::DynTypedNode &DynNode,
80                  ASTMatchFinder *Finder,
81                  BoundNodesTreeBuilder *Builder) const override {
82    bool Result = InnerMatcher->dynMatches(DynNode, Finder, Builder);
83    if (Result) Builder->setBinding(ID, DynNode);
84    return Result;
85  }
86
87 private:
88  const std::string ID;
89  const IntrusiveRefCntPtr<DynMatcherInterface> InnerMatcher;
90};
91
92/// \brief A matcher that always returns true.
93///
94/// We only ever need one instance of this matcher, so we create a global one
95/// and reuse it to reduce the overhead of the matcher and increase the chance
96/// of cache hits.
97class TrueMatcherImpl : public DynMatcherInterface {
98public:
99  TrueMatcherImpl() {
100    Retain(); // Reference count will never become zero.
101  }
102  bool dynMatches(const ast_type_traits::DynTypedNode &, ASTMatchFinder *,
103                  BoundNodesTreeBuilder *) const override {
104    return true;
105  }
106};
107static llvm::ManagedStatic<TrueMatcherImpl> TrueMatcherInstance;
108
109}  // namespace
110
111DynTypedMatcher DynTypedMatcher::constructVariadic(
112    DynTypedMatcher::VariadicOperator Op,
113    std::vector<DynTypedMatcher> InnerMatchers) {
114  assert(InnerMatchers.size() > 0 && "Array must not be empty.");
115  assert(std::all_of(InnerMatchers.begin(), InnerMatchers.end(),
116                     [&InnerMatchers](const DynTypedMatcher &M) {
117           return InnerMatchers[0].SupportedKind.isSame(M.SupportedKind);
118         }) &&
119         "SupportedKind must match!");
120
121  auto SupportedKind = InnerMatchers[0].SupportedKind;
122  // We must relax the restrict kind here.
123  // The different operators might deal differently with a mismatch.
124  // Make it the same as SupportedKind, since that is the broadest type we are
125  // allowed to accept.
126  auto RestrictKind = SupportedKind;
127
128  switch (Op) {
129  case VO_AllOf:
130    // In the case of allOf() we must pass all the checks, so making
131    // RestrictKind the most restrictive can save us time. This way we reject
132    // invalid types earlier and we can elide the kind checks inside the
133    // matcher.
134    for (auto &IM : InnerMatchers) {
135      RestrictKind = ast_type_traits::ASTNodeKind::getMostDerivedType(
136          RestrictKind, IM.RestrictKind);
137    }
138    return DynTypedMatcher(
139        SupportedKind, RestrictKind,
140        new VariadicMatcher<AllOfVariadicOperator>(std::move(InnerMatchers)));
141
142  case VO_AnyOf:
143    return DynTypedMatcher(
144        SupportedKind, RestrictKind,
145        new VariadicMatcher<AnyOfVariadicOperator>(std::move(InnerMatchers)));
146
147  case VO_EachOf:
148    return DynTypedMatcher(
149        SupportedKind, RestrictKind,
150        new VariadicMatcher<EachOfVariadicOperator>(std::move(InnerMatchers)));
151
152  case VO_UnaryNot:
153    // FIXME: Implement the Not operator to take a single matcher instead of a
154    // vector.
155    return DynTypedMatcher(
156        SupportedKind, RestrictKind,
157        new VariadicMatcher<NotUnaryOperator>(std::move(InnerMatchers)));
158  }
159  llvm_unreachable("Invalid Op value.");
160}
161
162DynTypedMatcher DynTypedMatcher::trueMatcher(
163    ast_type_traits::ASTNodeKind NodeKind) {
164  return DynTypedMatcher(NodeKind, NodeKind, &*TrueMatcherInstance);
165}
166
167bool DynTypedMatcher::canMatchNodesOfKind(
168    ast_type_traits::ASTNodeKind Kind) const {
169  return RestrictKind.isBaseOf(Kind);
170}
171
172DynTypedMatcher DynTypedMatcher::dynCastTo(
173    const ast_type_traits::ASTNodeKind Kind) const {
174  auto Copy = *this;
175  Copy.SupportedKind = Kind;
176  Copy.RestrictKind =
177      ast_type_traits::ASTNodeKind::getMostDerivedType(Kind, RestrictKind);
178  return Copy;
179}
180
181bool DynTypedMatcher::matches(const ast_type_traits::DynTypedNode &DynNode,
182                              ASTMatchFinder *Finder,
183                              BoundNodesTreeBuilder *Builder) const {
184  if (RestrictKind.isBaseOf(DynNode.getNodeKind()) &&
185      Implementation->dynMatches(DynNode, Finder, Builder)) {
186    return true;
187  }
188  // Delete all bindings when a matcher does not match.
189  // This prevents unexpected exposure of bound nodes in unmatches
190  // branches of the match tree.
191  Builder->removeBindings([](const BoundNodesMap &) { return true; });
192  return false;
193}
194
195bool DynTypedMatcher::matchesNoKindCheck(
196    const ast_type_traits::DynTypedNode &DynNode, ASTMatchFinder *Finder,
197    BoundNodesTreeBuilder *Builder) const {
198  assert(RestrictKind.isBaseOf(DynNode.getNodeKind()));
199  if (Implementation->dynMatches(DynNode, Finder, Builder)) {
200    return true;
201  }
202  // Delete all bindings when a matcher does not match.
203  // This prevents unexpected exposure of bound nodes in unmatches
204  // branches of the match tree.
205  Builder->removeBindings([](const BoundNodesMap &) { return true; });
206  return false;
207}
208
209llvm::Optional<DynTypedMatcher> DynTypedMatcher::tryBind(StringRef ID) const {
210  if (!AllowBind) return llvm::None;
211  auto Result = *this;
212  Result.Implementation = new IdDynMatcher(ID, Result.Implementation);
213  return Result;
214}
215
216bool DynTypedMatcher::canConvertTo(ast_type_traits::ASTNodeKind To) const {
217  const auto From = getSupportedKind();
218  auto QualKind = ast_type_traits::ASTNodeKind::getFromNodeKind<QualType>();
219  auto TypeKind = ast_type_traits::ASTNodeKind::getFromNodeKind<Type>();
220  /// Mimic the implicit conversions of Matcher<>.
221  /// - From Matcher<Type> to Matcher<QualType>
222  if (From.isSame(TypeKind) && To.isSame(QualKind)) return true;
223  /// - From Matcher<Base> to Matcher<Derived>
224  return From.isBaseOf(To);
225}
226
227void BoundNodesTreeBuilder::addMatch(const BoundNodesTreeBuilder &Other) {
228  Bindings.append(Other.Bindings.begin(), Other.Bindings.end());
229}
230
231bool NotUnaryOperator(const ast_type_traits::DynTypedNode DynNode,
232                      ASTMatchFinder *Finder, BoundNodesTreeBuilder *Builder,
233                      ArrayRef<DynTypedMatcher> InnerMatchers) {
234  if (InnerMatchers.size() != 1)
235    return false;
236
237  // The 'unless' matcher will always discard the result:
238  // If the inner matcher doesn't match, unless returns true,
239  // but the inner matcher cannot have bound anything.
240  // If the inner matcher matches, the result is false, and
241  // any possible binding will be discarded.
242  // We still need to hand in all the bound nodes up to this
243  // point so the inner matcher can depend on bound nodes,
244  // and we need to actively discard the bound nodes, otherwise
245  // the inner matcher will reset the bound nodes if it doesn't
246  // match, but this would be inversed by 'unless'.
247  BoundNodesTreeBuilder Discard(*Builder);
248  return !InnerMatchers[0].matches(DynNode, Finder, &Discard);
249}
250
251bool AllOfVariadicOperator(const ast_type_traits::DynTypedNode DynNode,
252                           ASTMatchFinder *Finder,
253                           BoundNodesTreeBuilder *Builder,
254                           ArrayRef<DynTypedMatcher> InnerMatchers) {
255  // allOf leads to one matcher for each alternative in the first
256  // matcher combined with each alternative in the second matcher.
257  // Thus, we can reuse the same Builder.
258  for (const DynTypedMatcher &InnerMatcher : InnerMatchers) {
259    if (!InnerMatcher.matchesNoKindCheck(DynNode, Finder, Builder))
260      return false;
261  }
262  return true;
263}
264
265bool EachOfVariadicOperator(const ast_type_traits::DynTypedNode DynNode,
266                            ASTMatchFinder *Finder,
267                            BoundNodesTreeBuilder *Builder,
268                            ArrayRef<DynTypedMatcher> InnerMatchers) {
269  BoundNodesTreeBuilder Result;
270  bool Matched = false;
271  for (const DynTypedMatcher &InnerMatcher : InnerMatchers) {
272    BoundNodesTreeBuilder BuilderInner(*Builder);
273    if (InnerMatcher.matches(DynNode, Finder, &BuilderInner)) {
274      Matched = true;
275      Result.addMatch(BuilderInner);
276    }
277  }
278  *Builder = std::move(Result);
279  return Matched;
280}
281
282bool AnyOfVariadicOperator(const ast_type_traits::DynTypedNode DynNode,
283                           ASTMatchFinder *Finder,
284                           BoundNodesTreeBuilder *Builder,
285                           ArrayRef<DynTypedMatcher> InnerMatchers) {
286  for (const DynTypedMatcher &InnerMatcher : InnerMatchers) {
287    BoundNodesTreeBuilder Result = *Builder;
288    if (InnerMatcher.matches(DynNode, Finder, &Result)) {
289      *Builder = std::move(Result);
290      return true;
291    }
292  }
293  return false;
294}
295
296HasNameMatcher::HasNameMatcher(StringRef NameRef)
297    : UseUnqualifiedMatch(NameRef.find("::") == NameRef.npos), Name(NameRef) {
298  assert(!Name.empty());
299}
300
301bool HasNameMatcher::matchesNodeUnqualified(const NamedDecl &Node) const {
302  assert(UseUnqualifiedMatch);
303  if (Node.getIdentifier()) {
304    // Simple name.
305    return Name == Node.getName();
306  }
307  if (Node.getDeclName()) {
308    // Name needs to be constructed.
309    llvm::SmallString<128> NodeName;
310    llvm::raw_svector_ostream OS(NodeName);
311    Node.printName(OS);
312    return Name == OS.str();
313  }
314  return false;
315}
316
317bool HasNameMatcher::matchesNodeFull(const NamedDecl &Node) const {
318  llvm::SmallString<128> NodeName = StringRef("::");
319  llvm::raw_svector_ostream OS(NodeName);
320  Node.printQualifiedName(OS);
321  const StringRef FullName = OS.str();
322  const StringRef Pattern = Name;
323
324  if (Pattern.startswith("::"))
325    return FullName == Pattern;
326
327  return FullName.endswith(Pattern) &&
328         FullName.drop_back(Pattern.size()).endswith("::");
329}
330
331bool HasNameMatcher::matchesNode(const NamedDecl &Node) const {
332  // FIXME: There is still room for improvement, but it would require copying a
333  // lot of the logic from NamedDecl::printQualifiedName(). The benchmarks do
334  // not show like that extra complexity is needed right now.
335  if (UseUnqualifiedMatch) {
336    assert(matchesNodeUnqualified(Node) == matchesNodeFull(Node));
337    return matchesNodeUnqualified(Node);
338  }
339  return matchesNodeFull(Node);
340}
341
342} // end namespace internal
343} // end namespace ast_matchers
344} // end namespace clang
345