clang-tools 8.0.0

HelperDeclRefGraph.h
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1 //===-- UsedHelperDeclFinder.h - AST-based call graph for helper decls ----===//
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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_MOVE_USED_HELPER_DECL_FINDER_H
11 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_MOVE_USED_HELPER_DECL_FINDER_H
12
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14 #include "clang/Analysis/CallGraph.h"
15 #include "llvm/ADT/DenseSet.h"
16 #include <memory>
17 #include <vector>
18
19 namespace clang {
20 namespace move {
21
22 // A reference graph for finding used/unused helper declarations in a single
23 // translation unit (e.g. old.cc). We don't reuse CallGraph in clang/Analysis
24 // because that CallGraph only supports function declarations.
25 //
26 // Helper declarations include following types:
27 // * function/variable/class definitions in an anonymous namespace.
28 // * static function/variable definitions in a global/named namespace.
29 //
30 // The reference graph is a directed graph. Each node in the graph represents a
31 // helper declaration in old.cc or a non-moved/moved declaration (e.g. class,
32 // function) in old.h, which means each node is associated with a Decl.
33 //
34 // To construct the graph, we use AST matcher to find interesting Decls (usually
35 // a pair of Caller and Callee), and add an edge from the Caller node to the
36 // Callee node.
37 //
38 // Specially, for a class, it might have multiple declarations such methods
39 // and member variables. We only use a single node to present this class, and
40 // this node is associated with the class declaration (CXXRecordDecl).
41 //
42 // The graph has 3 types of edges:
43 // 1. moved_decl => helper_decl
44 // 2. non_moved_decl => helper_decl
45 // 3. helper_decl => helper_decl
46 class HelperDeclRefGraph {
47 public:
48 HelperDeclRefGraph() = default;
49 ~HelperDeclRefGraph() = default;
50
51 // Add a directed edge from the caller node to the callee node.
52 // A new node will be created if the node for Caller/Callee doesn't exist.
53 //
54 // Note that, all class member declarations are represented by a single node
55 // in the graph. The corresponding Decl of this node is the class declaration.
56 void addEdge(const Decl *Caller, const Decl *Callee);
57 CallGraphNode *getNode(const Decl *D) const;
58
59 // Get all reachable nodes in the graph from the given declaration D's node,
60 // including D.
61 llvm::DenseSet<const CallGraphNode *> getReachableNodes(const Decl *D) const;
62
63 // Dump the call graph for debug purpose.
64 void dump() const;
65
66 private:
67 void print(raw_ostream &OS) const;
68 // Lookup a node for the given declaration D. If not found, insert a new
69 // node into the graph.
70 CallGraphNode *getOrInsertNode(Decl *D);
71
72 typedef llvm::DenseMap<const Decl *, std::unique_ptr<CallGraphNode>>
73 DeclMapTy;
74
75 // DeclMap owns all CallGraphNodes.
76 DeclMapTy DeclMap;
77 };
78
79 // A builder helps to construct a call graph of helper declarations.
80 class HelperDeclRGBuilder : public ast_matchers::MatchFinder::MatchCallback {
81 public:
82 HelperDeclRGBuilder() : RG(new HelperDeclRefGraph) {}
83 void run(const ast_matchers::MatchFinder::MatchResult &Result) override;
84 const HelperDeclRefGraph *getGraph() const { return RG.get(); }
85
86 // Find out the outmost enclosing class/function declaration of a given D.
87 // For a CXXMethodDecl, get its CXXRecordDecl; For a VarDecl/FunctionDecl, get
88 // its outmost enclosing FunctionDecl or CXXRecordDecl.
89 // Return D if not found.
90 static const Decl *getOutmostClassOrFunDecl(const Decl *D);
91
92 private:
93 std::unique_ptr<HelperDeclRefGraph> RG;
94 };
95
96 } // namespace move
97 } // namespace clang
98
99 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_MOVE_USED_HELPER_DECL_FINDER_H
clang::move::HelperDeclRefGraph
Definition: HelperDeclRefGraph.h:46
clang::move::HelperDeclRefGraph::HelperDeclRefGraph
HelperDeclRefGraph()=default
clang::move::HelperDeclRefGraph::getReachableNodes
llvm::DenseSet< const CallGraphNode * > getReachableNodes(const Decl *D) const
Definition: HelperDeclRefGraph.cpp:73
clang::move::HelperDeclRGBuilder
Definition: HelperDeclRefGraph.h:80
clang::move::HelperDeclRefGraph::addEdge
void addEdge(const Decl *Caller, const Decl *Callee)
Definition: HelperDeclRefGraph.cpp:39
D
const Decl * D
Definition: XRefs.cpp:79
clang::move::HelperDeclRefGraph::dump
void dump() const
Definition: HelperDeclRefGraph.cpp:55
Result
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: ClangdServer.cpp:60
clang::move::HelperDeclRGBuilder::getGraph
const HelperDeclRefGraph * getGraph() const
Definition: HelperDeclRefGraph.h:84
clang::move::HelperDeclRGBuilder::HelperDeclRGBuilder
HelperDeclRGBuilder()
Definition: HelperDeclRefGraph.h:82
clang::move::HelperDeclRefGraph::~HelperDeclRefGraph
~HelperDeclRefGraph()=default
clang::move::HelperDeclRefGraph::getNode
CallGraphNode * getNode(const Decl *D) const
Definition: HelperDeclRefGraph.cpp:67
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ChangeNamespace.cpp:18