//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
-// This file implements the CallGraph class.
+// This file implements the CallGraph class and provides the BasicCallGraph
+// default implementation.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/CallGraph.h"
-#include "llvm/Constants.h" // Remove when ConstantPointerRefs are gone
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/Support/CallSite.h"
-#include "llvm/ADT/STLExtras.h"
-#include <iostream>
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Streams.h"
+#include <ostream>
using namespace llvm;
-static RegisterAnalysis<CallGraph> X("callgraph", "Call Graph Construction");
+namespace {
-// getNodeFor - Return the node for the specified function or create one if it
-// does not already exist.
+//===----------------------------------------------------------------------===//
+// BasicCallGraph class definition
//
-CallGraphNode *CallGraph::getNodeFor(Function *F) {
- CallGraphNode *&CGN = FunctionMap[F];
- if (CGN) return CGN;
+class VISIBILITY_HIDDEN 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;
- assert((!F || F->getParent() == Mod) && "Function not in current module!");
- return CGN = new CallGraphNode(F);
-}
+ // ExternalCallingNode - This node has edges to all external functions and
+ // those internal functions that have their address taken.
+ CallGraphNode *ExternalCallingNode;
-static bool isOnlyADirectCall(Function *F, CallSite CS) {
- if (!CS.getInstruction()) return false;
- for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); I != E; ++I)
- if (*I == F) return false;
- return true;
-}
+ // CallsExternalNode - This node has edges to it from all functions making
+ // indirect calls or calling an external function.
+ CallGraphNode *CallsExternalNode;
-// addToCallGraph - Add a function to the call graph, and link the node to all
-// of the functions that it calls.
-//
-void CallGraph::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!
- }
+public:
+ static char ID; // Class identification, replacement for typeinfo
+ BasicCallGraph() : ModulePass(&ID), Root(0),
+ ExternalCallingNode(0), CallsExternalNode(0) {}
+
+ // runOnModule - Compute the call graph for the specified module.
+ virtual bool runOnModule(Module &M) {
+ CallGraph::initialize(M);
+
+ ExternalCallingNode = getOrInsertFunction(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;
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ }
+
+ void print(std::ostream *o, const Module *M) const {
+ if (o) print(*o, M);
+ }
+
+ 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();
}
- // If this function is not defined in this translation unit, it could call
- // anything.
- if (F->isExternal() && !F->getIntrinsicID())
- Node->addCalledFunction(CallsExternalNode);
+ /// dump - Print out this call graph.
+ ///
+ inline void dump() const {
+ print(cerr, Mod);
+ }
+
+ CallGraphNode* getExternalCallingNode() const { return ExternalCallingNode; }
+ CallGraphNode* getCallsExternalNode() const { return CallsExternalNode; }
- // Loop over all of the users of the function... looking for callers...
+ // getRoot - Return the root of the call graph, which is either main, or if
+ // main cannot be found, the external node.
//
- 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
+ CallGraphNode *getRoot() { return Root; }
+ const CallGraphNode *getRoot() const { return Root; }
+
+private:
+ //===---------------------------------------------------------------------
+ // Implementation of CallGraph construction
+ //
+
+ // 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 = getOrInsertFunction(F);
+
+ // If this function has external linkage, anything could call it.
+ if (!F->hasInternalLinkage()) {
+ ExternalCallingNode->addCalledFunction(CallSite(), 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->isDeclaration() && !F->isIntrinsic())
+ Node->addCalledFunction(CallSite(), CallsExternalNode);
+
+ // Loop over all of the users of the function, looking for non-call uses.
+ bool isUsedExternally = false;
+ for (Value::use_iterator I = F->use_begin(), E = F->use_end();
+ I != E && !isUsedExternally; ++I) {
+ if (Instruction *Inst = dyn_cast<Instruction>(*I)) {
+ CallSite CS = CallSite::get(Inst);
+ // Not a call? Or F being passed as a parameter not as the callee?
+ isUsedExternally = !CS.getInstruction() || I.getOperandNo();
+ } else { // User is not a direct call!
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);
+ }
+ }
+ if (isUsedExternally)
+ ExternalCallingNode->addCalledFunction(CallSite(), Node);
+
+ // Look for calls by this function.
+ 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()) {
+ const Function *Callee = CS.getCalledFunction();
+ if (Callee)
+ Node->addCalledFunction(CS, getOrInsertFunction(Callee));
else
- isUsedExternally = true;
- } else {
- isUsedExternally = true;
+ Node->addCalledFunction(CS, CallsExternalNode);
}
- } else { // Can't classify the user!
- isUsedExternally = true;
- }
+ }
}
- 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){
- CallSite CS = CallSite::get(II);
- if (CS.getInstruction() && !CS.getCalledFunction())
- Node->addCalledFunction(CallsExternalNode);
- }
-}
-bool CallGraph::run(Module &M) {
- destroy();
+ //
+ // destroy - Release memory for the call graph
+ virtual void destroy() {
+ /// CallsExternalNode is not in the function map, delete it explicitly.
+ delete CallsExternalNode;
+ CallsExternalNode = 0;
+ CallGraph::destroy();
+ }
+};
- Mod = &M;
- ExternalCallingNode = getNodeFor(0);
- CallsExternalNode = new CallGraphNode(0);
- Root = 0;
+} //End anonymous namespace
- // Add every function to the call graph...
- for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
- addToCallGraph(I);
+static RegisterAnalysisGroup<CallGraph> X("Call Graph");
+static RegisterPass<BasicCallGraph>
+Y("basiccg", "Basic CallGraph Construction", false, true);
+static RegisterAnalysisGroup<CallGraph, true> Z(Y);
- // If we didn't find a main function, use the external call graph node
- if (Root == 0) Root = ExternalCallingNode;
-
- return false;
-}
+char CallGraph::ID = 0;
+char BasicCallGraph::ID = 0;
-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 CallGraph::initialize(Module &M) {
+ Mod = &M;
}
-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 CallGraph::destroy() {
+ if (!FunctionMap.empty()) {
+ 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);
+ print(cerr, 0);
}
-
//===----------------------------------------------------------------------===//
// Implementations of public modification methods
//
FunctionMap.erase(I);
}
+// getOrInsertFunction - This method is identical to calling operator[], but
+// it will insert a new CallGraphNode for the specified function if one does
+// not already exist.
+CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
+ CallGraphNode *&CGN = FunctionMap[F];
+ if (CGN) return CGN;
+
+ assert((!F || F->getParent() == Mod) && "Function not in current module!");
+ return CGN = new CallGraphNode(const_cast<Function*>(F));
+}
+
+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";
-void CallGraph::stub() {}
+ for (const_iterator I = begin(), E = end(); I != E; ++I)
+ if (I->second->getFunction())
+ OS << " Calls function '" << I->second->getFunction()->getName() <<"'\n";
+ else
+ OS << " Calls external node\n";
+ OS << "\n";
+}
+
+void CallGraphNode::dump() const { print(cerr); }
-void CallGraphNode::removeCallEdgeTo(CallGraphNode *Callee) {
+/// removeCallEdgeFor - This method removes the edge in the node for the
+/// specified call site. Note that this method takes linear time, so it
+/// should be used sparingly.
+void CallGraphNode::removeCallEdgeFor(CallSite CS) {
for (unsigned i = CalledFunctions.size(); ; --i) {
- assert(i && "Cannot find callee to remove!");
- if (CalledFunctions[i-1] == Callee) {
+ assert(i && "Cannot find callsite to remove!");
+ if (CalledFunctions[i-1].first == CS) {
CalledFunctions.erase(CalledFunctions.begin()+i-1);
return;
}
}
}
+
// removeAnyCallEdgeTo - This method removes any call edges from this node to
// the specified callee function. This takes more time to execute than
// removeCallEdgeTo, so it should not be used unless necessary.
void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
- for (std::vector<CallGraphNode*>::iterator I = CalledFunctions.begin(),
- E = CalledFunctions.end(); I != E; ++I)
- if (*I == Callee) {
- CalledFunctions.erase(I);
- E = CalledFunctions.end();
+ for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
+ if (CalledFunctions[i].second == Callee) {
+ CalledFunctions[i] = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ --i; --e;
+ }
+}
+
+/// replaceCallSite - Make the edge in the node for Old CallSite be for
+/// New CallSite instead. Note that this method takes linear time, so it
+/// should be used sparingly.
+void CallGraphNode::replaceCallSite(CallSite Old, CallSite New) {
+ for (unsigned i = CalledFunctions.size(); ; --i) {
+ assert(i && "Cannot find callsite to replace!");
+ if (CalledFunctions[i-1].first == Old) {
+ CalledFunctions[i-1].first = New;
+ return;
}
+ }
}
+
+// Enuse that users of CallGraph.h also link with this file
+DEFINING_FILE_FOR(CallGraph)
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