// This interface is used to build and manipulate a call graph, which is a very
// useful tool for interprocedural optimization.
//
-// Every method in a module is represented as a node in the call graph. The
-// callgraph node keeps track of which methods the are called by the method
+// Every function in a module is represented as a node in the call graph. The
+// callgraph node keeps track of which functions the are called by the function
// corresponding to the node.
//
-// A call graph will contain nodes where the method that they correspond to is
+// A call graph will contain nodes where the function that they correspond to is
// null. This 'external' node is used to represent control flow that is not
// represented (or analyzable) in the module. As such, the external node will
-// have edges to methods with the following properties:
-// 1. All methods in the module without internal linkage, since they could
-// be called by methods outside of the our analysis capability.
-// 2. All methods whose address is used for something more than a direct call,
-// for example being stored into a memory location. Since they may be
-// called by an unknown caller later, they must be tracked as such.
+// have edges to functions with the following properties:
+// 1. All functions in the module without internal linkage, since they could
+// be called by functions outside of the our analysis capability.
+// 2. All functions whose address is used for something more than a direct
+// call, for example being stored into a memory location. Since they may
+// be called by an unknown caller later, they must be tracked as such.
//
-// Similarly, methods have a call edge to the external node iff:
-// 1. The method is external, reflecting the fact that they could call
+// Similarly, functions have a call edge to the external node iff:
+// 1. The function is external, reflecting the fact that they could call
// anything without internal linkage or that has its address taken.
-// 2. The method contains an indirect method call.
+// 2. The function contains an indirect function call.
//
// As an extension in the future, there may be multiple nodes with a null
-// method. These will be used when we can prove (through pointer analysis) that
-// an indirect call site can call only a specific set of methods.
+// function. These will be used when we can prove (through pointer analysis)
+// that an indirect call site can call only a specific set of functions.
//
// Because of these properties, the CallGraph captures a conservative superset
// of all of the caller-callee relationships, which is useful for
// transformations.
//
// The CallGraph class also attempts to figure out what the root of the
-// CallGraph is, which is currently does by looking for a method named 'main'.
-// If no method named 'main' is found, the external node is used as the entry
-// node, reflecting the fact that any method without internal linkage could
+// CallGraph is, which is currently does by looking for a function named 'main'.
+// If no function named 'main' is found, the external node is used as the entry
+// node, reflecting the fact that any function without internal linkage could
// be called into (which is common for libraries).
//
//===----------------------------------------------------------------------===//
AnalysisID CallGraph::ID(AnalysisID::create<CallGraph>());
-// getNodeFor - Return the node for the specified method or create one if it
+// getNodeFor - Return the node for the specified function or create one if it
// does not already exist.
//
CallGraphNode *CallGraph::getNodeFor(Function *F) {
- CallGraphNode *&CGN = MethodMap[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 method to the call graph, and link the node to all of
-// the methods that it calls.
+// addToCallGraph - Add a function to the call graph, and link the node to all
+// of the functions that it calls.
//
void CallGraph::addToCallGraph(Function *M) {
CallGraphNode *Node = getNodeFor(M);
- // If this method has external linkage,
+ // If this function has external linkage,
if (!M->hasInternalLinkage()) {
- ExternalNode->addCalledMethod(Node);
+ ExternalNode->addCalledFunction(Node);
// Found the entry point?
if (M->getName() == "main") {
Root = Node; // Found a main, keep track of it!
}
} else if (M->isExternal()) { // Not defined in this xlation unit?
- Node->addCalledMethod(ExternalNode); // It could call anything...
+ Node->addCalledFunction(ExternalNode); // It could call anything...
}
- // Loop over all of the users of the method... looking for callers...
+ // Loop over all of the users of the function... looking for callers...
//
for (Value::use_iterator I = M->use_begin(), E = M->use_end(); I != E; ++I) {
User *U = *I;
if (CallInst *CI = dyn_cast<CallInst>(U))
- getNodeFor(CI->getParent()->getParent())->addCalledMethod(Node);
+ getNodeFor(CI->getParent()->getParent())->addCalledFunction(Node);
else if (InvokeInst *II = dyn_cast<InvokeInst>(U))
- getNodeFor(II->getParent()->getParent())->addCalledMethod(Node);
+ getNodeFor(II->getParent()->getParent())->addCalledFunction(Node);
else // Can't classify the user!
- ExternalNode->addCalledMethod(Node);
+ ExternalNode->addCalledFunction(Node);
}
- // Look for an indirect method call...
+ // Look for an indirect function call...
for (Function::iterator BB = M->begin(), BBE = M->end(); BB != BBE; ++BB)
for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; ++II){
Instruction &I = *II;
if (CallInst *CI = dyn_cast<CallInst>(&I)) {
if (CI->getCalledFunction() == 0)
- Node->addCalledMethod(ExternalNode);
+ Node->addCalledFunction(ExternalNode);
} else if (InvokeInst *II = dyn_cast<InvokeInst>(&I)) {
if (II->getCalledFunction() == 0)
- Node->addCalledMethod(ExternalNode);
+ Node->addCalledFunction(ExternalNode);
}
}
}
ExternalNode = getNodeFor(0);
Root = 0;
- // Add every method to the call graph...
+ // 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 method, use the external call graph node
+ // If we didn't find a main function, use the external call graph node
if (Root == 0) Root = ExternalNode;
return false;
}
void CallGraph::destroy() {
- for (MethodMapTy::iterator I = MethodMap.begin(), E = MethodMap.end();
+ for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
I != E; ++I)
delete I->second;
- MethodMap.clear();
+ FunctionMap.clear();
}
void WriteToOutput(const CallGraphNode *CGN, std::ostream &o) {
- if (CGN->getMethod())
- o << "Call graph node for method: '" << CGN->getMethod()->getName() <<"'\n";
+ if (CGN->getFunction())
+ o << "Call graph node for function: '"
+ << CGN->getFunction()->getName() <<"'\n";
else
- o << "Call graph node null method:\n";
+ o << "Call graph node null function:\n";
for (unsigned i = 0; i < CGN->size(); ++i)
- if ((*CGN)[i]->getMethod())
- o << " Calls method '" << (*CGN)[i]->getMethod()->getName() << "'\n";
+ if ((*CGN)[i]->getFunction())
+ o << " Calls function '" << (*CGN)[i]->getFunction()->getName() << "'\n";
else
o << " Calls external node\n";
o << "\n";
// Implementations of public modification methods
//
-// Methods to keep a call graph up to date with a method that has been
+// Functions to keep a call graph up to date with a function that has been
// modified
//
-void CallGraph::addMethodToModule(Function *Meth) {
+void CallGraph::addFunctionToModule(Function *Meth) {
assert(0 && "not implemented");
abort();
}
-// removeMethodFromModule - Unlink the method from this module, returning it.
-// Because this removes the method from the module, the call graph node is
-// destroyed. This is only valid if the method does not call any other
-// methods (ie, there are no edges in it's CGN). The easiest way to do this
+// removeFunctionFromModule - Unlink the function from this module, returning
+// it. Because this removes the function from the module, the call graph node
+// is destroyed. This is only valid if the function does not call any other
+// functions (ie, there are no edges in it's CGN). The easiest way to do this
// is to dropAllReferences before calling this.
//
-Function *CallGraph::removeMethodFromModule(CallGraphNode *CGN) {
- assert(CGN->CalledMethods.empty() && "Cannot remove method from call graph"
- " if it references other methods!");
- Function *M = CGN->getMethod(); // Get the function for the call graph node
- delete CGN; // Delete the call graph node for this func
- MethodMap.erase(M); // Remove the call graph node from the map
+Function *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
+ assert(CGN->CalledFunctions.empty() && "Cannot remove function from call "
+ "graph if it references other functions!");
+ Function *M = CGN->getFunction(); // Get the function for the call graph node
+ delete CGN; // Delete the call graph node for this func
+ FunctionMap.erase(M); // Remove the call graph node from the map
Mod->getFunctionList().remove(M);
return M;