1 files changed, 207 insertions, 0 deletions
diff --git a/lib/Analysis/CallGraph.cpp b/lib/Analysis/CallGraph.cpp
new file mode 100644
index 0000000000..2aaeaf132d
--- /dev/null
+++ b/lib/Analysis/CallGraph.cpp
@@ -0,0 +1,207 @@
+//== CallGraph.cpp - AST-based Call graph  ----------------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the AST-based CallGraph.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Analysis/CallGraph.h"
+
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/StmtVisitor.h"
+
+#include "llvm/Support/GraphWriter.h"
+
+using namespace clang;
+
+/// Determine if a declaration should be included in the graph.
+static bool includeInGraph(const Decl *D) {
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    // We skip function template definitions, as their semantics is
+    // only determined when they are instantiated.
+    if (!FD->isThisDeclarationADefinition() ||
+        FD->isDependentContext())
+      return false;
+
+    IdentifierInfo *II = FD->getIdentifier();
+    if (II && II->getName().startswith("__inline"))
+      return false;
+  }
+
+  if (const ObjCMethodDecl *ID = dyn_cast<ObjCMethodDecl>(D)) {
+    if (!ID->isThisDeclarationADefinition())
+      return false;
+  }
+
+  return true;
+}
+
+namespace {
+/// A helper class, which walks the AST and locates all the call sites in the
+/// given function body.
+class CGBuilder : public StmtVisitor<CGBuilder> {
+  CallGraph *G;
+  const Decl *FD;
+  CallGraphNode *CallerNode;
+
+public:
+  CGBuilder(CallGraph *g, const Decl *D, CallGraphNode *N)
+    : G(g), FD(D), CallerNode(N) {}
+
+  void VisitStmt(Stmt *S) { VisitChildren(S); }
+
+  void VisitCallExpr(CallExpr *CE) {
+    // TODO: We need to handle ObjC method calls as well.
+    if (FunctionDecl *CalleeDecl = CE->getDirectCallee())
+      if (includeInGraph(CalleeDecl)) {
+        CallGraphNode *CalleeNode = G->getOrInsertFunction(CalleeDecl);
+        CallerNode->addCallee(CalleeNode, G);
+      }
+  };
+
+  void VisitChildren(Stmt *S) {
+    for (Stmt::child_range I = S->children(); I; ++I)
+      if (*I)
+        static_cast<CGBuilder*>(this)->Visit(*I);
+  }
+};
+} // end anonymous namespace
+
+CallGraph::CallGraph() {
+  Root = getOrInsertFunction(0);
+}
+
+CallGraph::~CallGraph() {
+  if (!FunctionMap.empty()) {
+    for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
+        I != E; ++I)
+      delete I->second;
+    FunctionMap.clear();
+  }
+}
+
+void CallGraph::addToCallGraph(Decl* D, bool IsGlobal) {
+  CallGraphNode *Node = getOrInsertFunction(D);
+
+  if (IsGlobal)
+    Root->addCallee(Node, this);
+
+  // Process all the calls by this function as well.
+  CGBuilder builder(this, D, Node);
+  builder.Visit(D->getBody());
+}
+
+void CallGraph::addToCallGraph(DeclContext *DC) {
+  for (DeclContext::decl_iterator I = DC->decls_begin(), E = DC->decls_end();
+       I != E; ++I) {
+    Decl *D = *I;
+    switch (D->getKind()) {
+    case Decl::CXXConstructor:
+    case Decl::CXXDestructor:
+    case Decl::CXXConversion:
+    case Decl::CXXMethod:
+    case Decl::Function: {
+      FunctionDecl *FD = cast<FunctionDecl>(D);
+      // We skip function template definitions, as their semantics is
+      // only determined when they are instantiated.
+      if (includeInGraph(FD))
+        // If this function has external linkage, anything could call it.
+        // Note, we are not precise here. For example, the function could have
+        // its address taken.
+        addToCallGraph(FD, FD->isGlobal());
+      break;
+    }
+
+    case Decl::ObjCCategoryImpl:
+    case Decl::ObjCImplementation: {
+      ObjCImplDecl *ID = cast<ObjCImplDecl>(D);
+      for (ObjCContainerDecl::method_iterator MI = ID->meth_begin(),
+          ME = ID->meth_end(); MI != ME; ++MI) {
+        if (includeInGraph(*MI))
+          addToCallGraph(*MI, true);
+      }
+      break;
+    }
+
+    default:
+      break;
+    }
+  }
+}
+
+CallGraphNode *CallGraph::getOrInsertFunction(Decl *F) {
+  CallGraphNode *&Node = FunctionMap[F];
+  if (Node)
+    return Node;
+
+  Node = new CallGraphNode(F);
+  ParentlessNodes.insert(Node);
+  return Node;
+}
+
+void CallGraph::print(raw_ostream &OS) const {
+  OS << " --- Call graph Dump --- \n";
+  for (const_iterator I = begin(), E = end(); I != E; ++I) {
+    OS << "  Function: ";
+    if (I->second == Root)
+      OS << "< root >";
+    else
+      I->second->print(OS);
+    OS << " calls: ";
+    for (CallGraphNode::iterator CI = I->second->begin(),
+        CE = I->second->end(); CI != CE; ++CI) {
+      assert(*CI != Root && "No one can call the root node.");
+      (*CI)->print(OS);
+      OS << " ";
+    }
+    OS << '\n';
+  }
+  OS.flush();
+}
+
+void CallGraph::dump() const {
+  print(llvm::errs());
+}
+
+void CallGraph::viewGraph() const {
+  llvm::ViewGraph(this, "CallGraph");
+}
+
+StringRef CallGraphNode::getName() const {
+  if (const FunctionDecl *D = dyn_cast_or_null<FunctionDecl>(FD))
+    if (const IdentifierInfo *II = D->getIdentifier())
+      return II->getName();
+    return "< >";
+}
+
+void CallGraphNode::print(raw_ostream &os) const {
+  os << getName();
+}
+
+void CallGraphNode::dump() const {
+  print(llvm::errs());
+}
+
+namespace llvm {
+
+template <>
+struct DOTGraphTraits<const CallGraph*> : public DefaultDOTGraphTraits {
+
+  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
+
+  static std::string getNodeLabel(const CallGraphNode *Node,
+                                  const CallGraph *CG) {
+    if (CG->getRoot() == Node) {
+      return "< root >";
+    }
+    return Node->getName();
+  }
+
+};
+}