1 //== CallGraph.cpp - Call graph building ------------------------*- C++ -*--==//
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 // This file defined the CallGraph and CGBuilder classes.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/Index/CallGraph.h"
15
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/StmtVisitor.h"
18
19 #include "llvm/Support/GraphWriter.h"
20
21 using namespace clang;
22 using namespace idx;
23
24 namespace {
25 class CGBuilder : public StmtVisitor<CGBuilder> {
26
27 CallGraph &G;
28 FunctionDecl *FD;
29
30 Entity CallerEnt;
31
32 CallGraphNode *CallerNode;
33
34 public:
CGBuilder(CallGraph & g,FunctionDecl * fd,Entity E,CallGraphNode * N)35 CGBuilder(CallGraph &g, FunctionDecl *fd, Entity E, CallGraphNode *N)
36 : G(g), FD(fd), CallerEnt(E), CallerNode(N) {}
37
VisitStmt(Stmt * S)38 void VisitStmt(Stmt *S) { VisitChildren(S); }
39
40 void VisitCallExpr(CallExpr *CE);
41
VisitChildren(Stmt * S)42 void VisitChildren(Stmt *S) {
43 for (Stmt::child_range I = S->children(); I; ++I)
44 if (*I)
45 static_cast<CGBuilder*>(this)->Visit(*I);
46 }
47 };
48 }
49
VisitCallExpr(CallExpr * CE)50 void CGBuilder::VisitCallExpr(CallExpr *CE) {
51 if (FunctionDecl *CalleeDecl = CE->getDirectCallee()) {
52 Entity Ent = Entity::get(CalleeDecl, G.getProgram());
53 CallGraphNode *CalleeNode = G.getOrInsertFunction(Ent);
54 CallerNode->addCallee(ASTLocation(FD, CE), CalleeNode);
55 }
56 }
57
CallGraph(Program & P)58 CallGraph::CallGraph(Program &P) : Prog(P), Root(0) {
59 ExternalCallingNode = getOrInsertFunction(Entity());
60 }
61
~CallGraph()62 CallGraph::~CallGraph() {
63 if (!FunctionMap.empty()) {
64 for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
65 I != E; ++I)
66 delete I->second;
67 FunctionMap.clear();
68 }
69 }
70
addTU(ASTContext & Ctx)71 void CallGraph::addTU(ASTContext& Ctx) {
72 DeclContext *DC = Ctx.getTranslationUnitDecl();
73 for (DeclContext::decl_iterator I = DC->decls_begin(), E = DC->decls_end();
74 I != E; ++I) {
75
76 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
77 if (FD->doesThisDeclarationHaveABody()) {
78 // Set caller's ASTContext.
79 Entity Ent = Entity::get(FD, Prog);
80 CallGraphNode *Node = getOrInsertFunction(Ent);
81 CallerCtx[Node] = &Ctx;
82
83 // If this function has external linkage, anything could call it.
84 if (FD->isGlobal())
85 ExternalCallingNode->addCallee(idx::ASTLocation(), Node);
86
87 // Set root node to 'main' function.
88 if (FD->getNameAsString() == "main")
89 Root = Node;
90
91 CGBuilder builder(*this, FD, Ent, Node);
92 builder.Visit(FD->getBody());
93 }
94 }
95 }
96 }
97
getOrInsertFunction(Entity F)98 CallGraphNode *CallGraph::getOrInsertFunction(Entity F) {
99 CallGraphNode *&Node = FunctionMap[F];
100 if (Node)
101 return Node;
102
103 return Node = new CallGraphNode(F);
104 }
105
getDecl(CallGraphNode * Node)106 Decl *CallGraph::getDecl(CallGraphNode *Node) {
107 // Get the function's context.
108 ASTContext *Ctx = CallerCtx[Node];
109
110 return Node->getDecl(*Ctx);
111 }
112
print(llvm::raw_ostream & os)113 void CallGraph::print(llvm::raw_ostream &os) {
114 for (iterator I = begin(), E = end(); I != E; ++I) {
115 if (I->second->hasCallee()) {
116 os << "function: " << I->first.getPrintableName()
117 << " calls:\n";
118 for (CallGraphNode::iterator CI = I->second->begin(),
119 CE = I->second->end(); CI != CE; ++CI) {
120 os << " " << CI->second->getName();
121 }
122 os << '\n';
123 }
124 }
125 }
126
dump()127 void CallGraph::dump() {
128 print(llvm::errs());
129 }
130
ViewCallGraph() const131 void CallGraph::ViewCallGraph() const {
132 llvm::ViewGraph(*this, "CallGraph");
133 }
134
135 namespace llvm {
136
137 template <>
138 struct DOTGraphTraits<CallGraph> : public DefaultDOTGraphTraits {
139
DOTGraphTraitsllvm::DOTGraphTraits140 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
141
getNodeLabelllvm::DOTGraphTraits142 static std::string getNodeLabel(const CallGraphNode *Node,
143 const CallGraph &CG) {
144 return Node->getName();
145
146 }
147
148 };
149
150 }
151