//===--- ASTMatchFinder.cpp - Structural query framework ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implements an algorithm to efficiently search for matches on AST nodes.
// Uses memoization to support recursive matches like HasDescendant.
//
// The general idea is to visit all AST nodes with a RecursiveASTVisitor,
// calling the Matches(...) method of each matcher we are running on each
// AST node. The matcher can recurse via the ASTMatchFinder interface.
//
//===----------------------------------------------------------------------===//
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/Timer.h"
#include <deque>
#include <memory>
#include <set>
namespace clang {
namespace ast_matchers {
namespace internal {
namespace {
typedef MatchFinder::MatchCallback MatchCallback;
// The maximum number of memoization entries to store.
// 10k has been experimentally found to give a good trade-off
// of performance vs. memory consumption by running matcher
// that match on every statement over a very large codebase.
//
// FIXME: Do some performance optimization in general and
// revisit this number; also, put up micro-benchmarks that we can
// optimize this on.
static const unsigned MaxMemoizationEntries = 10000;
// We use memoization to avoid running the same matcher on the same
// AST node twice. This struct is the key for looking up match
// result. It consists of an ID of the MatcherInterface (for
// identifying the matcher), a pointer to the AST node and the
// bound nodes before the matcher was executed.
//
// We currently only memoize on nodes whose pointers identify the
// nodes (\c Stmt and \c Decl, but not \c QualType or \c TypeLoc).
// For \c QualType and \c TypeLoc it is possible to implement
// generation of keys for each type.
// FIXME: Benchmark whether memoization of non-pointer typed nodes
// provides enough benefit for the additional amount of code.
struct MatchKey {
DynTypedMatcher::MatcherIDType MatcherID;
ast_type_traits::DynTypedNode Node;
BoundNodesTreeBuilder BoundNodes;
bool operator<(const MatchKey &Other) const {
return std::tie(MatcherID, Node, BoundNodes) <
std::tie(Other.MatcherID, Other.Node, Other.BoundNodes);
}
};
// Used to store the result of a match and possibly bound nodes.
struct MemoizedMatchResult {
bool ResultOfMatch;
BoundNodesTreeBuilder Nodes;
};
// A RecursiveASTVisitor that traverses all children or all descendants of
// a node.
class MatchChildASTVisitor
: public RecursiveASTVisitor<MatchChildASTVisitor> {
public:
typedef RecursiveASTVisitor<MatchChildASTVisitor> VisitorBase;
// Creates an AST visitor that matches 'matcher' on all children or
// descendants of a traversed node. max_depth is the maximum depth
// to traverse: use 1 for matching the children and INT_MAX for
// matching the descendants.
MatchChildASTVisitor(const DynTypedMatcher *Matcher,
ASTMatchFinder *Finder,
BoundNodesTreeBuilder *Builder,
int MaxDepth,
ASTMatchFinder::TraversalKind Traversal,
ASTMatchFinder::BindKind Bind)
: Matcher(Matcher),
Finder(Finder),
Builder(Builder),
CurrentDepth(0),
MaxDepth(MaxDepth),
Traversal(Traversal),
Bind(Bind),
Matches(false) {}
// Returns true if a match is found in the subtree rooted at the
// given AST node. This is done via a set of mutually recursive
// functions. Here's how the recursion is done (the *wildcard can
// actually be Decl, Stmt, or Type):
//
// - Traverse(node) calls BaseTraverse(node) when it needs
// to visit the descendants of node.
// - BaseTraverse(node) then calls (via VisitorBase::Traverse*(node))
// Traverse*(c) for each child c of 'node'.
// - Traverse*(c) in turn calls Traverse(c), completing the
// recursion.
bool findMatch(const ast_type_traits::DynTypedNode &DynNode) {
reset();
if (const Decl *D = DynNode.get<Decl>())
traverse(*D);
else if (const Stmt *S = DynNode.get<Stmt>())
traverse(*S);
else if (const NestedNameSpecifier *NNS =
DynNode.get<NestedNameSpecifier>())
traverse(*NNS);
else if (const NestedNameSpecifierLoc *NNSLoc =
DynNode.get<NestedNameSpecifierLoc>())
traverse(*NNSLoc);
else if (const QualType *Q = DynNode.get<QualType>())
traverse(*Q);
else if (const TypeLoc *T = DynNode.get<TypeLoc>())
traverse(*T);
// FIXME: Add other base types after adding tests.
// It's OK to always overwrite the bound nodes, as if there was
// no match in this recursive branch, the result set is empty
// anyway.
*Builder = ResultBindings;
return Matches;
}
// The following are overriding methods from the base visitor class.
// They are public only to allow CRTP to work. They are *not *part
// of the public API of this class.
bool TraverseDecl(Decl *DeclNode) {
ScopedIncrement ScopedDepth(&CurrentDepth);
return (DeclNode == nullptr) || traverse(*DeclNode);
}
bool TraverseStmt(Stmt *StmtNode) {
ScopedIncrement ScopedDepth(&CurrentDepth);
const Stmt *StmtToTraverse = StmtNode;
if (Traversal ==
ASTMatchFinder::TK_IgnoreImplicitCastsAndParentheses) {
const Expr *ExprNode = dyn_cast_or_null<Expr>(StmtNode);
if (ExprNode) {
StmtToTraverse = ExprNode->IgnoreParenImpCasts();
}
}
return (StmtToTraverse == nullptr) || traverse(*StmtToTraverse);
}
// We assume that the QualType and the contained type are on the same
// hierarchy level. Thus, we try to match either of them.
bool TraverseType(QualType TypeNode) {
if (TypeNode.isNull())
return true;
ScopedIncrement ScopedDepth(&CurrentDepth);
// Match the Type.
if (!match(*TypeNode))
return false;
// The QualType is matched inside traverse.
return traverse(TypeNode);
}
// We assume that the TypeLoc, contained QualType and contained Type all are
// on the same hierarchy level. Thus, we try to match all of them.
bool TraverseTypeLoc(TypeLoc TypeLocNode) {
if (TypeLocNode.isNull())
return true;
ScopedIncrement ScopedDepth(&CurrentDepth);
// Match the Type.
if (!match(*TypeLocNode.getType()))
return false;
// Match the QualType.
if (!match(TypeLocNode.getType()))
return false;
// The TypeLoc is matched inside traverse.
return traverse(TypeLocNode);
}
bool TraverseNestedNameSpecifier(NestedNameSpecifier *NNS) {
ScopedIncrement ScopedDepth(&CurrentDepth);
return (NNS == nullptr) || traverse(*NNS);
}
bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
if (!NNS)
return true;
ScopedIncrement ScopedDepth(&CurrentDepth);
if (!match(*NNS.getNestedNameSpecifier()))
return false;
return traverse(NNS);
}
bool shouldVisitTemplateInstantiations() const { return true; }
bool shouldVisitImplicitCode() const { return true; }
private:
// Used for updating the depth during traversal.
struct ScopedIncrement {
explicit ScopedIncrement(int *Depth) : Depth(Depth) { ++(*Depth); }
~ScopedIncrement() { --(*Depth); }
private:
int *Depth;
};
// Resets the state of this object.
void reset() {
Matches = false;
CurrentDepth = 0;
}
// Forwards the call to the corresponding Traverse*() method in the
// base visitor class.
bool baseTraverse(const Decl &DeclNode) {
return VisitorBase::TraverseDecl(const_cast<Decl*>(&DeclNode));
}
bool baseTraverse(const Stmt &StmtNode) {
return VisitorBase::TraverseStmt(const_cast<Stmt*>(&StmtNode));
}
bool baseTraverse(QualType TypeNode) {
return VisitorBase::TraverseType(TypeNode);
}
bool baseTraverse(TypeLoc TypeLocNode) {
return VisitorBase::TraverseTypeLoc(TypeLocNode);
}
bool baseTraverse(const NestedNameSpecifier &NNS) {
return VisitorBase::TraverseNestedNameSpecifier(
const_cast<NestedNameSpecifier*>(&NNS));
}
bool baseTraverse(NestedNameSpecifierLoc NNS) {
return VisitorBase::TraverseNestedNameSpecifierLoc(NNS);
}
// Sets 'Matched' to true if 'Matcher' matches 'Node' and:
// 0 < CurrentDepth <= MaxDepth.
//
// Returns 'true' if traversal should continue after this function
// returns, i.e. if no match is found or 'Bind' is 'BK_All'.
template <typename T>
bool match(const T &Node) {
if (CurrentDepth == 0 || CurrentDepth > MaxDepth) {
return true;
}
if (Bind != ASTMatchFinder::BK_All) {
BoundNodesTreeBuilder RecursiveBuilder(*Builder);
if (Matcher->matches(ast_type_traits::DynTypedNode::create(Node), Finder,
&RecursiveBuilder)) {
Matches = true;
ResultBindings.addMatch(RecursiveBuilder);
return false; // Abort as soon as a match is found.
}
} else {
BoundNodesTreeBuilder RecursiveBuilder(*Builder);
if (Matcher->matches(ast_type_traits::DynTypedNode::create(Node), Finder,
&RecursiveBuilder)) {
// After the first match the matcher succeeds.
Matches = true;
ResultBindings.addMatch(RecursiveBuilder);
}
}
return true;
}
// Traverses the subtree rooted at 'Node'; returns true if the
// traversal should continue after this function returns.
template <typename T>
bool traverse(const T &Node) {
static_assert(IsBaseType<T>::value,
"traverse can only be instantiated with base type");
if (!match(Node))
return false;
return baseTraverse(Node);
}
const DynTypedMatcher *const Matcher;
ASTMatchFinder *const Finder;
BoundNodesTreeBuilder *const Builder;
BoundNodesTreeBuilder ResultBindings;
int CurrentDepth;
const int MaxDepth;
const ASTMatchFinder::TraversalKind Traversal;
const ASTMatchFinder::BindKind Bind;
bool Matches;
};
// Controls the outermost traversal of the AST and allows to match multiple
// matchers.
class MatchASTVisitor : public RecursiveASTVisitor<MatchASTVisitor>,
public ASTMatchFinder {
public:
MatchASTVisitor(const MatchFinder::MatchersByType *Matchers,
const MatchFinder::MatchFinderOptions &Options)
: Matchers(Matchers), Options(Options), ActiveASTContext(nullptr) {}
~MatchASTVisitor() override {
if (Options.CheckProfiling) {
Options.CheckProfiling->Records = std::move(TimeByBucket);
}
}
void onStartOfTranslationUnit() {
const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
TimeBucketRegion Timer;
for (MatchCallback *MC : Matchers->AllCallbacks) {
if (EnableCheckProfiling)
Timer.setBucket(&TimeByBucket[MC->getID()]);
MC->onStartOfTranslationUnit();
}
}
void onEndOfTranslationUnit() {
const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
TimeBucketRegion Timer;
for (MatchCallback *MC : Matchers->AllCallbacks) {
if (EnableCheckProfiling)
Timer.setBucket(&TimeByBucket[MC->getID()]);
MC->onEndOfTranslationUnit();
}
}
void set_active_ast_context(ASTContext *NewActiveASTContext) {
ActiveASTContext = NewActiveASTContext;
}
// The following Visit*() and Traverse*() functions "override"
// methods in RecursiveASTVisitor.
bool VisitTypedefNameDecl(TypedefNameDecl *DeclNode) {
// When we see 'typedef A B', we add name 'B' to the set of names
// A's canonical type maps to. This is necessary for implementing
// isDerivedFrom(x) properly, where x can be the name of the base
// class or any of its aliases.
//
// In general, the is-alias-of (as defined by typedefs) relation
// is tree-shaped, as you can typedef a type more than once. For
// example,
//
// typedef A B;
// typedef A C;
// typedef C D;
// typedef C E;
//
// gives you
//
// A
// |- B
// `- C
// |- D
// `- E
//
// It is wrong to assume that the relation is a chain. A correct
// implementation of isDerivedFrom() needs to recognize that B and
// E are aliases, even though neither is a typedef of the other.
// Therefore, we cannot simply walk through one typedef chain to
// find out whether the type name matches.
const Type *TypeNode = DeclNode->getUnderlyingType().getTypePtr();
const Type *CanonicalType = // root of the typedef tree
ActiveASTContext->getCanonicalType(TypeNode);
TypeAliases[CanonicalType].insert(DeclNode);
return true;
}
bool TraverseDecl(Decl *DeclNode);
bool TraverseStmt(Stmt *StmtNode);
bool TraverseType(QualType TypeNode);
bool TraverseTypeLoc(TypeLoc TypeNode);
bool TraverseNestedNameSpecifier(NestedNameSpecifier *NNS);
bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS);
// Matches children or descendants of 'Node' with 'BaseMatcher'.
bool memoizedMatchesRecursively(const ast_type_traits::DynTypedNode &Node,
const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder, int MaxDepth,
TraversalKind Traversal, BindKind Bind) {
// For AST-nodes that don't have an identity, we can't memoize.
if (!Node.getMemoizationData() || !Builder->isComparable())
return matchesRecursively(Node, Matcher, Builder, MaxDepth, Traversal,
Bind);
MatchKey Key;
Key.MatcherID = Matcher.getID();
Key.Node = Node;
// Note that we key on the bindings *before* the match.
Key.BoundNodes = *Builder;
MemoizationMap::iterator I = ResultCache.find(Key);
if (I != ResultCache.end()) {
*Builder = I->second.Nodes;
return I->second.ResultOfMatch;
}
MemoizedMatchResult Result;
Result.Nodes = *Builder;
Result.ResultOfMatch = matchesRecursively(Node, Matcher, &Result.Nodes,
MaxDepth, Traversal, Bind);
MemoizedMatchResult &CachedResult = ResultCache[Key];
CachedResult = std::move(Result);
*Builder = CachedResult.Nodes;
return CachedResult.ResultOfMatch;
}
// Matches children or descendants of 'Node' with 'BaseMatcher'.
bool matchesRecursively(const ast_type_traits::DynTypedNode &Node,
const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder, int MaxDepth,
TraversalKind Traversal, BindKind Bind) {
MatchChildASTVisitor Visitor(
&Matcher, this, Builder, MaxDepth, Traversal, Bind);
return Visitor.findMatch(Node);
}
bool classIsDerivedFrom(const CXXRecordDecl *Declaration,
const Matcher<NamedDecl> &Base,
BoundNodesTreeBuilder *Builder) override;
// Implements ASTMatchFinder::matchesChildOf.
bool matchesChildOf(const ast_type_traits::DynTypedNode &Node,
const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder,
TraversalKind Traversal,
BindKind Bind) override {
if (ResultCache.size() > MaxMemoizationEntries)
ResultCache.clear();
return memoizedMatchesRecursively(Node, Matcher, Builder, 1, Traversal,
Bind);
}
// Implements ASTMatchFinder::matchesDescendantOf.
bool matchesDescendantOf(const ast_type_traits::DynTypedNode &Node,
const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder,
BindKind Bind) override {
if (ResultCache.size() > MaxMemoizationEntries)
ResultCache.clear();
return memoizedMatchesRecursively(Node, Matcher, Builder, INT_MAX,
TK_AsIs, Bind);
}
// Implements ASTMatchFinder::matchesAncestorOf.
bool matchesAncestorOf(const ast_type_traits::DynTypedNode &Node,
const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder,
AncestorMatchMode MatchMode) override {
// Reset the cache outside of the recursive call to make sure we
// don't invalidate any iterators.
if (ResultCache.size() > MaxMemoizationEntries)
ResultCache.clear();
return memoizedMatchesAncestorOfRecursively(Node, Matcher, Builder,
MatchMode);
}
// Matches all registered matchers on the given node and calls the
// result callback for every node that matches.
void match(const ast_type_traits::DynTypedNode &Node) {
// FIXME: Improve this with a switch or a visitor pattern.
if (auto *N = Node.get<Decl>()) {
match(*N);
} else if (auto *N = Node.get<Stmt>()) {
match(*N);
} else if (auto *N = Node.get<Type>()) {
match(*N);
} else if (auto *N = Node.get<QualType>()) {
match(*N);
} else if (auto *N = Node.get<NestedNameSpecifier>()) {
match(*N);
} else if (auto *N = Node.get<NestedNameSpecifierLoc>()) {
match(*N);
} else if (auto *N = Node.get<TypeLoc>()) {
match(*N);
}
}
template <typename T> void match(const T &Node) {
matchDispatch(&Node);
}
// Implements ASTMatchFinder::getASTContext.
ASTContext &getASTContext() const override { return *ActiveASTContext; }
bool shouldVisitTemplateInstantiations() const { return true; }
bool shouldVisitImplicitCode() const { return true; }
private:
class TimeBucketRegion {
public:
TimeBucketRegion() : Bucket(nullptr) {}
~TimeBucketRegion() { setBucket(nullptr); }
/// \brief Start timing for \p NewBucket.
///
/// If there was a bucket already set, it will finish the timing for that
/// other bucket.
/// \p NewBucket will be timed until the next call to \c setBucket() or
/// until the \c TimeBucketRegion is destroyed.
/// If \p NewBucket is the same as the currently timed bucket, this call
/// does nothing.
void setBucket(llvm::TimeRecord *NewBucket) {
if (Bucket != NewBucket) {
auto Now = llvm::TimeRecord::getCurrentTime(true);
if (Bucket)
*Bucket += Now;
if (NewBucket)
*NewBucket -= Now;
Bucket = NewBucket;
}
}
private:
llvm::TimeRecord *Bucket;
};
/// \brief Runs all the \p Matchers on \p Node.
///
/// Used by \c matchDispatch() below.
template <typename T, typename MC>
void matchWithoutFilter(const T &Node, const MC &Matchers) {
const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
TimeBucketRegion Timer;
for (const auto &MP : Matchers) {
if (EnableCheckProfiling)
Timer.setBucket(&TimeByBucket[MP.second->getID()]);
BoundNodesTreeBuilder Builder;
if (MP.first.matches(Node, this, &Builder)) {
MatchVisitor Visitor(ActiveASTContext, MP.second);
Builder.visitMatches(&Visitor);
}
}
}
void matchWithFilter(const ast_type_traits::DynTypedNode &DynNode) {
auto Kind = DynNode.getNodeKind();
auto it = MatcherFiltersMap.find(Kind);
const auto &Filter =
it != MatcherFiltersMap.end() ? it->second : getFilterForKind(Kind);
if (Filter.empty())
return;
const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
TimeBucketRegion Timer;
auto &Matchers = this->Matchers->DeclOrStmt;
for (unsigned short I : Filter) {
auto &MP = Matchers[I];
if (EnableCheckProfiling)
Timer.setBucket(&TimeByBucket[MP.second->getID()]);
BoundNodesTreeBuilder Builder;
if (MP.first.matchesNoKindCheck(DynNode, this, &Builder)) {
MatchVisitor Visitor(ActiveASTContext, MP.second);
Builder.visitMatches(&Visitor);
}
}
}
const std::vector<unsigned short> &
getFilterForKind(ast_type_traits::ASTNodeKind Kind) {
auto &Filter = MatcherFiltersMap[Kind];
auto &Matchers = this->Matchers->DeclOrStmt;
assert((Matchers.size() < USHRT_MAX) && "Too many matchers.");
for (unsigned I = 0, E = Matchers.size(); I != E; ++I) {
if (Matchers[I].first.canMatchNodesOfKind(Kind)) {
Filter.push_back(I);
}
}
return Filter;
}
/// @{
/// \brief Overloads to pair the different node types to their matchers.
void matchDispatch(const Decl *Node) {
return matchWithFilter(ast_type_traits::DynTypedNode::create(*Node));
}
void matchDispatch(const Stmt *Node) {
return matchWithFilter(ast_type_traits::DynTypedNode::create(*Node));
}
void matchDispatch(const Type *Node) {
matchWithoutFilter(QualType(Node, 0), Matchers->Type);
}
void matchDispatch(const TypeLoc *Node) {
matchWithoutFilter(*Node, Matchers->TypeLoc);
}
void matchDispatch(const QualType *Node) {
matchWithoutFilter(*Node, Matchers->Type);
}
void matchDispatch(const NestedNameSpecifier *Node) {
matchWithoutFilter(*Node, Matchers->NestedNameSpecifier);
}
void matchDispatch(const NestedNameSpecifierLoc *Node) {
matchWithoutFilter(*Node, Matchers->NestedNameSpecifierLoc);
}
void matchDispatch(const void *) { /* Do nothing. */ }
/// @}
// Returns whether an ancestor of \p Node matches \p Matcher.
//
// The order of matching ((which can lead to different nodes being bound in
// case there are multiple matches) is breadth first search.
//
// To allow memoization in the very common case of having deeply nested
// expressions inside a template function, we first walk up the AST, memoizing
// the result of the match along the way, as long as there is only a single
// parent.
//
// Once there are multiple parents, the breadth first search order does not
// allow simple memoization on the ancestors. Thus, we only memoize as long
// as there is a single parent.
bool memoizedMatchesAncestorOfRecursively(
const ast_type_traits::DynTypedNode &Node, const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder, AncestorMatchMode MatchMode) {
if (Node.get<TranslationUnitDecl>() ==
ActiveASTContext->getTranslationUnitDecl())
return false;
// For AST-nodes that don't have an identity, we can't memoize.
if (!Builder->isComparable())
return matchesAncestorOfRecursively(Node, Matcher, Builder, MatchMode);
MatchKey Key;
Key.MatcherID = Matcher.getID();
Key.Node = Node;
Key.BoundNodes = *Builder;
// Note that we cannot use insert and reuse the iterator, as recursive
// calls to match might invalidate the result cache iterators.
MemoizationMap::iterator I = ResultCache.find(Key);
if (I != ResultCache.end()) {
*Builder = I->second.Nodes;
return I->second.ResultOfMatch;
}
MemoizedMatchResult Result;
Result.Nodes = *Builder;
Result.ResultOfMatch =
matchesAncestorOfRecursively(Node, Matcher, &Result.Nodes, MatchMode);
MemoizedMatchResult &CachedResult = ResultCache[Key];
CachedResult = std::move(Result);
*Builder = CachedResult.Nodes;
return CachedResult.ResultOfMatch;
}
bool matchesAncestorOfRecursively(const ast_type_traits::DynTypedNode &Node,
const DynTypedMatcher &Matcher,
BoundNodesTreeBuilder *Builder,
AncestorMatchMode MatchMode) {
const auto &Parents = ActiveASTContext->getParents(Node);
assert(!Parents.empty() && "Found node that is not in the parent map.");
if (Parents.size() == 1) {
// Only one parent - do recursive memoization.
const ast_type_traits::DynTypedNode Parent = Parents[0];
BoundNodesTreeBuilder BuilderCopy = *Builder;
if (Matcher.matches(Parent, this, &BuilderCopy)) {
*Builder = std::move(BuilderCopy);
return true;
}
if (MatchMode != ASTMatchFinder::AMM_ParentOnly) {
return memoizedMatchesAncestorOfRecursively(Parent, Matcher, Builder,
MatchMode);
// Once we get back from the recursive call, the result will be the
// same as the parent's result.
}
} else {
// Multiple parents - BFS over the rest of the nodes.
llvm::DenseSet<const void *> Visited;
std::deque<ast_type_traits::DynTypedNode> Queue(Parents.begin(),
Parents.end());
while (!Queue.empty()) {
BoundNodesTreeBuilder BuilderCopy = *Builder;
if (Matcher.matches(Queue.front(), this, &BuilderCopy)) {
*Builder = std::move(BuilderCopy);
return true;
}
if (MatchMode != ASTMatchFinder::AMM_ParentOnly) {
for (const auto &Parent :
ActiveASTContext->getParents(Queue.front())) {
// Make sure we do not visit the same node twice.
// Otherwise, we'll visit the common ancestors as often as there
// are splits on the way down.
if (Visited.insert(Parent.getMemoizationData()).second)
Queue.push_back(Parent);
}
}
Queue.pop_front();
}
}
return false;
}
// Implements a BoundNodesTree::Visitor that calls a MatchCallback with
// the aggregated bound nodes for each match.
class MatchVisitor : public BoundNodesTreeBuilder::Visitor {
public:
MatchVisitor(ASTContext* Context,
MatchFinder::MatchCallback* Callback)
: Context(Context),
Callback(Callback) {}
void visitMatch(const BoundNodes& BoundNodesView) override {
Callback->run(MatchFinder::MatchResult(BoundNodesView, Context));
}
private:
ASTContext* Context;
MatchFinder::MatchCallback* Callback;
};
// Returns true if 'TypeNode' has an alias that matches the given matcher.
bool typeHasMatchingAlias(const Type *TypeNode,
const Matcher<NamedDecl> &Matcher,
BoundNodesTreeBuilder *Builder) {
const Type *const CanonicalType =
ActiveASTContext->getCanonicalType(TypeNode);
for (const TypedefNameDecl *Alias : TypeAliases.lookup(CanonicalType)) {
BoundNodesTreeBuilder Result(*Builder);
if (Matcher.matches(*Alias, this, &Result)) {
*Builder = std::move(Result);
return true;
}
}
return false;
}
/// \brief Bucket to record map.
///
/// Used to get the appropriate bucket for each matcher.
llvm::StringMap<llvm::TimeRecord> TimeByBucket;
const MatchFinder::MatchersByType *Matchers;
/// \brief Filtered list of matcher indices for each matcher kind.
///
/// \c Decl and \c Stmt toplevel matchers usually apply to a specific node
/// kind (and derived kinds) so it is a waste to try every matcher on every
/// node.
/// We precalculate a list of matchers that pass the toplevel restrict check.
/// This also allows us to skip the restrict check at matching time. See
/// use \c matchesNoKindCheck() above.
llvm::DenseMap<ast_type_traits::ASTNodeKind, std::vector<unsigned short>>
MatcherFiltersMap;
const MatchFinder::MatchFinderOptions &Options;
ASTContext *ActiveASTContext;
// Maps a canonical type to its TypedefDecls.
llvm::DenseMap<const Type*, std::set<const TypedefNameDecl*> > TypeAliases;
// Maps (matcher, node) -> the match result for memoization.
typedef std::map<MatchKey, MemoizedMatchResult> MemoizationMap;
MemoizationMap ResultCache;
};
static CXXRecordDecl *
getAsCXXRecordDeclOrPrimaryTemplate(const Type *TypeNode) {
if (auto *RD = TypeNode->getAsCXXRecordDecl())
return RD;
// Find the innermost TemplateSpecializationType that isn't an alias template.
auto *TemplateType = TypeNode->getAs<TemplateSpecializationType>();
while (TemplateType && TemplateType->isTypeAlias())
TemplateType =
TemplateType->getAliasedType()->getAs<TemplateSpecializationType>();
// If this is the name of a (dependent) template specialization, use the
// definition of the template, even though it might be specialized later.
if (TemplateType)
if (auto *ClassTemplate = dyn_cast_or_null<ClassTemplateDecl>(
TemplateType->getTemplateName().getAsTemplateDecl()))
return ClassTemplate->getTemplatedDecl();
return nullptr;
}
// Returns true if the given class is directly or indirectly derived
// from a base type with the given name. A class is not considered to be
// derived from itself.
bool MatchASTVisitor::classIsDerivedFrom(const CXXRecordDecl *Declaration,
const Matcher<NamedDecl> &Base,
BoundNodesTreeBuilder *Builder) {
if (!Declaration->hasDefinition())
return false;
for (const auto &It : Declaration->bases()) {
const Type *TypeNode = It.getType().getTypePtr();
if (typeHasMatchingAlias(TypeNode, Base, Builder))
return true;
// FIXME: Going to the primary template here isn't really correct, but
// unfortunately we accept a Decl matcher for the base class not a Type
// matcher, so it's the best thing we can do with our current interface.
CXXRecordDecl *ClassDecl = getAsCXXRecordDeclOrPrimaryTemplate(TypeNode);
if (!ClassDecl)
continue;
if (ClassDecl == Declaration) {
// This can happen for recursive template definitions; if the
// current declaration did not match, we can safely return false.
return false;
}
BoundNodesTreeBuilder Result(*Builder);
if (Base.matches(*ClassDecl, this, &Result)) {
*Builder = std::move(Result);
return true;
}
if (classIsDerivedFrom(ClassDecl, Base, Builder))
return true;
}
return false;
}
bool MatchASTVisitor::TraverseDecl(Decl *DeclNode) {
if (!DeclNode) {
return true;
}
match(*DeclNode);
return RecursiveASTVisitor<MatchASTVisitor>::TraverseDecl(DeclNode);
}
bool MatchASTVisitor::TraverseStmt(Stmt *StmtNode) {
if (!StmtNode) {
return true;
}
match(*StmtNode);
return RecursiveASTVisitor<MatchASTVisitor>::TraverseStmt(StmtNode);
}
bool MatchASTVisitor::TraverseType(QualType TypeNode) {
match(TypeNode);
return RecursiveASTVisitor<MatchASTVisitor>::TraverseType(TypeNode);
}
bool MatchASTVisitor::TraverseTypeLoc(TypeLoc TypeLocNode) {
// The RecursiveASTVisitor only visits types if they're not within TypeLocs.
// We still want to find those types via matchers, so we match them here. Note
// that the TypeLocs are structurally a shadow-hierarchy to the expressed
// type, so we visit all involved parts of a compound type when matching on
// each TypeLoc.
match(TypeLocNode);
match(TypeLocNode.getType());
return RecursiveASTVisitor<MatchASTVisitor>::TraverseTypeLoc(TypeLocNode);
}
bool MatchASTVisitor::TraverseNestedNameSpecifier(NestedNameSpecifier *NNS) {
match(*NNS);
return RecursiveASTVisitor<MatchASTVisitor>::TraverseNestedNameSpecifier(NNS);
}
bool MatchASTVisitor::TraverseNestedNameSpecifierLoc(
NestedNameSpecifierLoc NNS) {
if (!NNS)
return true;
match(NNS);
// We only match the nested name specifier here (as opposed to traversing it)
// because the traversal is already done in the parallel "Loc"-hierarchy.
if (NNS.hasQualifier())
match(*NNS.getNestedNameSpecifier());
return
RecursiveASTVisitor<MatchASTVisitor>::TraverseNestedNameSpecifierLoc(NNS);
}
class MatchASTConsumer : public ASTConsumer {
public:
MatchASTConsumer(MatchFinder *Finder,
MatchFinder::ParsingDoneTestCallback *ParsingDone)
: Finder(Finder), ParsingDone(ParsingDone) {}
private:
void HandleTranslationUnit(ASTContext &Context) override {
if (ParsingDone != nullptr) {
ParsingDone->run();
}
Finder->matchAST(Context);
}
MatchFinder *Finder;
MatchFinder::ParsingDoneTestCallback *ParsingDone;
};
} // end namespace
} // end namespace internal
MatchFinder::MatchResult::MatchResult(const BoundNodes &Nodes,
ASTContext *Context)
: Nodes(Nodes), Context(Context),
SourceManager(&Context->getSourceManager()) {}
MatchFinder::MatchCallback::~MatchCallback() {}
MatchFinder::ParsingDoneTestCallback::~ParsingDoneTestCallback() {}
MatchFinder::MatchFinder(MatchFinderOptions Options)
: Options(std::move(Options)), ParsingDone(nullptr) {}
MatchFinder::~MatchFinder() {}
void MatchFinder::addMatcher(const DeclarationMatcher &NodeMatch,
MatchCallback *Action) {
Matchers.DeclOrStmt.emplace_back(NodeMatch, Action);
Matchers.AllCallbacks.insert(Action);
}
void MatchFinder::addMatcher(const TypeMatcher &NodeMatch,
MatchCallback *Action) {
Matchers.Type.emplace_back(NodeMatch, Action);
Matchers.AllCallbacks.insert(Action);
}
void MatchFinder::addMatcher(const StatementMatcher &NodeMatch,
MatchCallback *Action) {
Matchers.DeclOrStmt.emplace_back(NodeMatch, Action);
Matchers.AllCallbacks.insert(Action);
}
void MatchFinder::addMatcher(const NestedNameSpecifierMatcher &NodeMatch,
MatchCallback *Action) {
Matchers.NestedNameSpecifier.emplace_back(NodeMatch, Action);
Matchers.AllCallbacks.insert(Action);
}
void MatchFinder::addMatcher(const NestedNameSpecifierLocMatcher &NodeMatch,
MatchCallback *Action) {
Matchers.NestedNameSpecifierLoc.emplace_back(NodeMatch, Action);
Matchers.AllCallbacks.insert(Action);
}
void MatchFinder::addMatcher(const TypeLocMatcher &NodeMatch,
MatchCallback *Action) {
Matchers.TypeLoc.emplace_back(NodeMatch, Action);
Matchers.AllCallbacks.insert(Action);
}
bool MatchFinder::addDynamicMatcher(const internal::DynTypedMatcher &NodeMatch,
MatchCallback *Action) {
if (NodeMatch.canConvertTo<Decl>()) {
addMatcher(NodeMatch.convertTo<Decl>(), Action);
return true;
} else if (NodeMatch.canConvertTo<QualType>()) {
addMatcher(NodeMatch.convertTo<QualType>(), Action);
return true;
} else if (NodeMatch.canConvertTo<Stmt>()) {
addMatcher(NodeMatch.convertTo<Stmt>(), Action);
return true;
} else if (NodeMatch.canConvertTo<NestedNameSpecifier>()) {
addMatcher(NodeMatch.convertTo<NestedNameSpecifier>(), Action);
return true;
} else if (NodeMatch.canConvertTo<NestedNameSpecifierLoc>()) {
addMatcher(NodeMatch.convertTo<NestedNameSpecifierLoc>(), Action);
return true;
} else if (NodeMatch.canConvertTo<TypeLoc>()) {
addMatcher(NodeMatch.convertTo<TypeLoc>(), Action);
return true;
}
return false;
}
std::unique_ptr<ASTConsumer> MatchFinder::newASTConsumer() {
return llvm::make_unique<internal::MatchASTConsumer>(this, ParsingDone);
}
void MatchFinder::match(const clang::ast_type_traits::DynTypedNode &Node,
ASTContext &Context) {
internal::MatchASTVisitor Visitor(&Matchers, Options);
Visitor.set_active_ast_context(&Context);
Visitor.match(Node);
}
void MatchFinder::matchAST(ASTContext &Context) {
internal::MatchASTVisitor Visitor(&Matchers, Options);
Visitor.set_active_ast_context(&Context);
Visitor.onStartOfTranslationUnit();
Visitor.TraverseDecl(Context.getTranslationUnitDecl());
Visitor.onEndOfTranslationUnit();
}
void MatchFinder::registerTestCallbackAfterParsing(
MatchFinder::ParsingDoneTestCallback *NewParsingDone) {
ParsingDone = NewParsingDone;
}
StringRef MatchFinder::MatchCallback::getID() const { return "<unknown>"; }
} // end namespace ast_matchers
} // end namespace clang