[llvm-commits] CVS: llvm/lib/Analysis/IPA/CallGraph.cpp

Chris Lattner lattner at cs.uiuc.edu
Wed Dec 21 22:08:04 PST 2005



Changes in directory llvm/lib/Analysis/IPA:

CallGraph.cpp updated: 1.48 -> 1.49
---
Log message:

Separate the call graph implementation from its interface.  This implements
the rough idea sketched out in http://nondot.org/sabre/LLVMNotes/CallGraphClass.txt,
allowing new spiffy implementations of the callgraph interface to be built.

Many thanks to Saem Ghani for contributing this!


---
Diffs of the changes:  (+179 -106)

 CallGraph.cpp |  285 ++++++++++++++++++++++++++++++++++++----------------------
 1 files changed, 179 insertions(+), 106 deletions(-)


Index: llvm/lib/Analysis/IPA/CallGraph.cpp
diff -u llvm/lib/Analysis/IPA/CallGraph.cpp:1.48 llvm/lib/Analysis/IPA/CallGraph.cpp:1.49
--- llvm/lib/Analysis/IPA/CallGraph.cpp:1.48	Thu Apr 21 16:08:44 2005
+++ llvm/lib/Analysis/IPA/CallGraph.cpp	Thu Dec 22 00:07:52 2005
@@ -7,7 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 //
-//  This file implements the CallGraph class.
+// This file implements the CallGraph class and provides the BasicCallGraph
+// default implementation.
 //
 //===----------------------------------------------------------------------===//
 
@@ -15,22 +16,10 @@
 #include "llvm/Module.h"
 #include "llvm/Instructions.h"
 #include "llvm/Support/CallSite.h"
-#include "llvm/ADT/STLExtras.h"
 #include <iostream>
 using namespace llvm;
 
-static RegisterAnalysis<CallGraph> X("callgraph", "Call Graph Construction");
-
-// getNodeFor - Return the node for the specified function or create one if it
-// does not already exist.
-//
-CallGraphNode *CallGraph::getNodeFor(Function *F) {
-  CallGraphNode *&CGN = FunctionMap[F];
-  if (CGN) return CGN;
-
-  assert((!F || F->getParent() == Mod) && "Function not in current module!");
-  return CGN = new CallGraphNode(F);
-}
+void llvm::BasicCallGraphStub() {}
 
 static bool isOnlyADirectCall(Function *F, CallSite CS) {
   if (!CS.getInstruction()) return false;
@@ -39,125 +28,194 @@
   return true;
 }
 
-// addToCallGraph - Add a function to the call graph, and link the node to all
-// of the functions that it calls.
+namespace {
+
+//===----------------------------------------------------------------------===//
+// BasicCallGraph class definition
 //
-void CallGraph::addToCallGraph(Function *F) {
-  CallGraphNode *Node = getNodeFor(F);
+class BasicCallGraph : public CallGraph, public ModulePass {
+  // Root is root of the call graph, or the external node if a 'main' function
+  // couldn't be found.
+  //
+  CallGraphNode *Root;
 
-  // If this function has external linkage, anything could call it...
-  if (!F->hasInternalLinkage()) {
-    ExternalCallingNode->addCalledFunction(Node);
-
-    // Found the entry point?
-    if (F->getName() == "main") {
-      if (Root)    // Found multiple external mains?  Don't pick one.
-        Root = ExternalCallingNode;
-      else
-        Root = Node;          // Found a main, keep track of it!
-    }
+  // ExternalCallingNode - This node has edges to all external functions and
+  // those internal functions that have their address taken.
+  CallGraphNode *ExternalCallingNode;
+
+  // CallsExternalNode - This node has edges to it from all functions making
+  // indirect calls or calling an external function.
+  CallGraphNode *CallsExternalNode;
+
+public:
+  BasicCallGraph() : Root(0), ExternalCallingNode(0), CallsExternalNode(0) {}
+  ~BasicCallGraph() { destroy(); }
+
+  // runOnModule - Compute the call graph for the specified module.
+  virtual bool runOnModule(Module &M) {
+    destroy();
+    CallGraph::initialize(M);
+    
+    ExternalCallingNode = getNodeFor(0);
+    CallsExternalNode = new CallGraphNode(0);
+    Root = 0;
+  
+    // Add every function to the call graph...
+    for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+      addToCallGraph(I);
+  
+    // If we didn't find a main function, use the external call graph node
+    if (Root == 0) Root = ExternalCallingNode;
+    
+    return false;
   }
 
-  // If this function is not defined in this translation unit, it could call
-  // anything.
-  if (F->isExternal() && !F->getIntrinsicID())
-    Node->addCalledFunction(CallsExternalNode);
-
-  // Loop over all of the users of the function... looking for callers...
-  //
-  bool isUsedExternally = false;
-  for (Value::use_iterator I = F->use_begin(), E = F->use_end(); I != E; ++I) {
-    if (Instruction *Inst = dyn_cast<Instruction>(*I)) {
-      if (isOnlyADirectCall(F, CallSite::get(Inst)))
-        getNodeFor(Inst->getParent()->getParent())->addCalledFunction(Node);
-      else
-        isUsedExternally = true;
-    } else if (GlobalValue *GV = dyn_cast<GlobalValue>(*I)) {
-      for (Value::use_iterator I = GV->use_begin(), E = GV->use_end();
-           I != E; ++I)
-        if (Instruction *Inst = dyn_cast<Instruction>(*I)) {
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.setPreservesAll();
+  }
+
+  virtual void print(std::ostream &o, const Module *M) const {
+    o << "CallGraph Root is: ";
+    if (Function *F = getRoot()->getFunction())
+      o << F->getName() << "\n";
+    else
+      o << "<<null function: 0x" << getRoot() << ">>\n";
+    
+    CallGraph::print(o, M);
+  }
+
+  virtual void releaseMemory() {
+    destroy();
+  }
+  
+  /// dump - Print out this call graph.
+  ///
+  inline void dump() const {
+    print(std::cerr, Mod);
+  }
+
+  CallGraphNode* getExternalCallingNode() const { return ExternalCallingNode; }
+  CallGraphNode* getCallsExternalNode()   const { return CallsExternalNode; }
+
+  // getRoot - Return the root of the call graph, which is either main, or if
+  // main cannot be found, the external node.
+  //
+  CallGraphNode *getRoot()             { return Root; }
+  const CallGraphNode *getRoot() const { return Root; }
+
+private:
+  //===---------------------------------------------------------------------
+  // Implementation of CallGraph construction
+  //
+  // getNodeFor - Return the node for the specified function or create one if it
+  // does not already exist.
+  //
+
+  CallGraphNode *getNodeFor(Function *F) {
+    CallGraphNode *&CGN = FunctionMap[F];
+    if (CGN) return CGN;
+
+    assert((!F || F->getParent() == Mod) && "Function not in current module!");
+    return CGN = new CallGraphNode(F);
+  }
+  
+  //
+  // addToCallGraph - Add a function to the call graph, and link the node to all
+  // of the functions that it calls.
+  //
+  void addToCallGraph(Function *F) {
+    CallGraphNode *Node = getNodeFor(F);
+
+    // If this function has external linkage, anything could call it...
+    if (!F->hasInternalLinkage()) {
+      ExternalCallingNode->addCalledFunction(Node);
+
+      // Found the entry point?
+      if (F->getName() == "main") {
+        if (Root)    // Found multiple external mains?  Don't pick one.
+          Root = ExternalCallingNode;
+        else
+          Root = Node;          // Found a main, keep track of it!
+      }
+    }
+
+    // If this function is not defined in this translation unit, it could call
+    // anything.
+    if (F->isExternal() && !F->getIntrinsicID())
+      Node->addCalledFunction(CallsExternalNode);
+
+    // Loop over all of the users of the function... looking for callers...
+    //
+    bool isUsedExternally = false;
+    for (Value::use_iterator I = F->use_begin(), E = F->use_end(); I != E; ++I){
+      if (Instruction *Inst = dyn_cast<Instruction>(*I)) {
+        if (isOnlyADirectCall(F, CallSite::get(Inst)))
+          getNodeFor(Inst->getParent()->getParent())->addCalledFunction(Node);
+        else
+          isUsedExternally = true;
+      } else if (GlobalValue *GV = dyn_cast<GlobalValue>(*I)) {
+        for (Value::use_iterator I = GV->use_begin(), E = GV->use_end();
+             I != E; ++I)
+          if (Instruction *Inst = dyn_cast<Instruction>(*I)) {
           if (isOnlyADirectCall(F, CallSite::get(Inst)))
             getNodeFor(Inst->getParent()->getParent())->addCalledFunction(Node);
           else
             isUsedExternally = true;
-        } else {
-          isUsedExternally = true;
-        }
-    } else {                        // Can't classify the user!
-      isUsedExternally = true;
+          } else {
+            isUsedExternally = true;
+          }
+      } else {                        // Can't classify the user!
+        isUsedExternally = true;
+      }
     }
-  }
-  if (isUsedExternally)
-    ExternalCallingNode->addCalledFunction(Node);
+    if (isUsedExternally)
+      ExternalCallingNode->addCalledFunction(Node);
 
   // Look for an indirect function call...
-  for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
-    for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; ++II){
+    for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
+      for (BasicBlock::iterator II = BB->begin(), IE = BB->end();
+           II != IE; ++II) {
       CallSite CS = CallSite::get(II);
       if (CS.getInstruction() && !CS.getCalledFunction())
         Node->addCalledFunction(CallsExternalNode);
-    }
-}
+      }
+  }
 
-bool CallGraph::runOnModule(Module &M) {
-  destroy();
+  //
+  // destroy - Release memory for the call graph
+  virtual void destroy() {
+    if (!CallsExternalNode) {
+      delete CallsExternalNode;
+      CallsExternalNode = 0;
+    }
+  }
+};
 
-  Mod = &M;
-  ExternalCallingNode = getNodeFor(0);
-  CallsExternalNode = new CallGraphNode(0);
-  Root = 0;
-
-  // Add every function to the call graph...
-  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
-    addToCallGraph(I);
+RegisterAnalysisGroup<CallGraph> X("Call Graph");
+RegisterOpt<BasicCallGraph> Y("basiccg", "Basic CallGraph Construction");
+RegisterAnalysisGroup<CallGraph, BasicCallGraph, true> Z;
 
-  // If we didn't find a main function, use the external call graph node
-  if (Root == 0) Root = ExternalCallingNode;
+} //End anonymous namespace
 
-  return false;
+void CallGraph::initialize(Module &M) {
+  destroy();
+  Mod = &M;
 }
 
 void CallGraph::destroy() {
-  for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
-       I != E; ++I)
-    delete I->second;
-  FunctionMap.clear();
-  delete CallsExternalNode;
-  CallsExternalNode = 0;
-}
-
-void CallGraphNode::print(std::ostream &OS) const {
-  if (Function *F = getFunction())
-    OS << "Call graph node for function: '" << F->getName() <<"'\n";
-  else
-    OS << "Call graph node <<null function: 0x" << this << ">>:\n";
-
-  for (const_iterator I = begin(), E = end(); I != E; ++I)
-    if ((*I)->getFunction())
-      OS << "  Calls function '" << (*I)->getFunction()->getName() << "'\n";
-    else
-      OS << "  Calls external node\n";
-  OS << "\n";
+  if(!FunctionMap.size()) {
+    for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
+        I != E; ++I)
+      delete I->second;
+    FunctionMap.clear();
+  }
 }
 
-void CallGraphNode::dump() const { print(std::cerr); }
-
 void CallGraph::print(std::ostream &OS, const Module *M) const {
-  OS << "CallGraph Root is: ";
-  if (Function *F = getRoot()->getFunction())
-    OS << F->getName() << "\n";
-  else
-    OS << "<<null function: 0x" << getRoot() << ">>\n";
-
   for (CallGraph::const_iterator I = begin(), E = end(); I != E; ++I)
     I->second->print(OS);
 }
 
-void CallGraph::dump() const {
-  print(std::cerr, 0);
-}
-
-
 //===----------------------------------------------------------------------===//
 // Implementations of public modification methods
 //
@@ -193,9 +251,24 @@
   FunctionMap.erase(I);
 }
 
-
 void CallGraph::stub() {}
 
+void CallGraphNode::print(std::ostream &OS) const {
+  if (Function *F = getFunction())
+    OS << "Call graph node for function: '" << F->getName() <<"'\n";
+  else
+    OS << "Call graph node <<null function: 0x" << this << ">>:\n";
+
+  for (const_iterator I = begin(), E = end(); I != E; ++I)
+    if ((*I)->getFunction())
+      OS << "  Calls function '" << (*I)->getFunction()->getName() << "'\n";
+  else
+    OS << "  Calls external node\n";
+  OS << "\n";
+}
+
+void CallGraphNode::dump() const { print(std::cerr); }
+
 void CallGraphNode::removeCallEdgeTo(CallGraphNode *Callee) {
   for (unsigned i = CalledFunctions.size(); ; --i) {
     assert(i && "Cannot find callee to remove!");






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