//===- 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.
-//
-//===----------------------------------------------------------------------===//
+// The LLVM Compiler Infrastructure
//
-// This file implements the CallGraph class.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/CallGraph.h"
-#include "llvm/Constants.h" // Remove when ConstantPointerRefs are gone
-#include "llvm/Module.h"
-#include "llvm/iOther.h"
-#include "llvm/iTerminators.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
#include "llvm/Support/CallSite.h"
-#include "Support/STLExtras.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
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);
+CallGraph::CallGraph()
+ : ModulePass(ID), Root(0), ExternalCallingNode(0), CallsExternalNode(0) {
+ initializeCallGraphPass(*PassRegistry::getPassRegistry());
}
-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;
-}
-
-// 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);
+ CallGraphNode *Node = getOrInsertFunction(F);
- // If this function has external linkage, anything could call it...
- if (!F->hasInternalLinkage()) {
- ExternalCallingNode->addCalledFunction(Node);
+ // If this function has external linkage, anything could call it.
+ if (!F->hasLocalLinkage()) {
+ ExternalCallingNode->addCalledFunction(CallSite(), Node);
// Found the entry point?
if (F->getName() == "main") {
- if (Root) // Found multiple external mains? Don't pick one.
+ if (Root) // Found multiple external mains? Don't pick one.
Root = ExternalCallingNode;
else
- Root = Node; // Found a main, keep track of it!
+ Root = Node; // Found a main, keep track of it!
}
}
-
+
+ // If this function has its address taken, anything could call it.
+ if (F->hasAddressTaken())
+ ExternalCallingNode->addCalledFunction(CallSite(), Node);
+
// 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;
- }
- }
- if (isUsedExternally)
- ExternalCallingNode->addCalledFunction(Node);
+ if (F->isDeclaration() && !F->isIntrinsic())
+ Node->addCalledFunction(CallSite(), CallsExternalNode);
- // Look for an indirect function call...
+ // 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() && !CS.getCalledFunction())
- Node->addCalledFunction(CallsExternalNode);
+ for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE;
+ ++II) {
+ CallSite CS(cast<Value>(II));
+ if (CS) {
+ const Function *Callee = CS.getCalledFunction();
+ if (!Callee)
+ // Indirect calls of intrinsics are not allowed so no need to check.
+ Node->addCalledFunction(CS, CallsExternalNode);
+ else if (!Callee->isIntrinsic())
+ Node->addCalledFunction(CS, getOrInsertFunction(Callee));
+ }
}
}
-bool CallGraph::run(Module &M) {
- destroy();
+void CallGraph::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+}
+
+bool CallGraph::runOnModule(Module &M) {
+ this->M = &M;
- Mod = &M;
- ExternalCallingNode = getNodeFor(0);
+ ExternalCallingNode = getOrInsertFunction(0);
+ assert(!CallsExternalNode);
CallsExternalNode = new CallGraphNode(0);
Root = 0;
- // Add every function 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 function, use the external call graph node
- if (Root == 0) Root = ExternalCallingNode;
-
+ if (Root == 0)
+ Root = ExternalCallingNode;
+
return false;
}
-void CallGraph::destroy() {
+INITIALIZE_PASS(CallGraph, "basiccg", "CallGraph Construction", false, true)
+
+char CallGraph::ID = 0;
+
+void CallGraph::releaseMemory() {
+ /// CallsExternalNode is not in the function map, delete it explicitly.
+ if (CallsExternalNode) {
+ CallsExternalNode->allReferencesDropped();
+ delete CallsExternalNode;
+ CallsExternalNode = 0;
+ }
+
+ if (FunctionMap.empty())
+ return;
+
+// Reset all node's use counts to zero before deleting them to prevent an
+// assertion from firing.
+#ifndef NDEBUG
for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
I != E; ++I)
+ I->second->allReferencesDropped();
+#endif
+
+ for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
+ I != E; ++I)
delete I->second;
FunctionMap.clear();
- delete CallsExternalNode;
- CallsExternalNode = 0;
}
-static void WriteToOutput(const CallGraphNode *CGN, std::ostream &o) {
- if (CGN->getFunction())
- o << "Call graph node for function: '"
- << CGN->getFunction()->getName() <<"'\n";
- else
- o << "Call graph node <<null function: 0x" << CGN << ">>:\n";
-
- for (unsigned i = 0; i < CGN->size(); ++i)
- if ((*CGN)[i]->getFunction())
- o << " Calls function '" << (*CGN)[i]->getFunction()->getName() << "'\n";
- else
- o << " Calls external node\n";
- o << "\n";
-}
+void CallGraph::print(raw_ostream &OS, const Module*) const {
+ OS << "CallGraph Root is: ";
+ if (Function *F = Root->getFunction())
+ OS << F->getName() << "\n";
+ else {
+ OS << "<<null function: 0x" << Root << ">>\n";
+ }
-void CallGraph::print(std::ostream &o, const Module *M) const {
- o << "CallGraph Root is: ";
- if (getRoot()->getFunction())
- o << getRoot()->getFunction()->getName() << "\n";
- else
- o << "<<null function: 0x" << getRoot() << ">>\n";
-
for (CallGraph::const_iterator I = begin(), E = end(); I != E; ++I)
- WriteToOutput(I->second, o);
+ I->second->print(OS);
}
-
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraph::dump() const {
+ print(dbgs(), 0);
+}
+#endif
//===----------------------------------------------------------------------===//
// Implementations of public modification methods
//
-// Functions to keep a call graph up to date with a function that has been
-// modified
-//
-void CallGraph::addFunctionToModule(Function *F) {
- assert(0 && "not implemented");
- abort();
-}
-
// 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
// is to dropAllReferences before calling this.
//
Function *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
- assert(CGN->CalledFunctions.empty() && "Cannot remove function from call "
+ assert(CGN->empty() && "Cannot remove function from call "
"graph if it references other functions!");
Function *F = CGN->getFunction(); // Get the function for the call graph node
delete CGN; // Delete the call graph node for this func
FunctionMap.erase(F); // Remove the call graph node from the map
- Mod->getFunctionList().remove(F);
+ M->getFunctionList().remove(F);
return F;
}
-void CallGraph::stub() {}
+/// spliceFunction - Replace the function represented by this node by another.
+/// This does not rescan the body of the function, so it is suitable when
+/// splicing the body of the old function to the new while also updating all
+/// callers from old to new.
+///
+void CallGraph::spliceFunction(const Function *From, const Function *To) {
+ assert(FunctionMap.count(From) && "No CallGraphNode for function!");
+ assert(!FunctionMap.count(To) &&
+ "Pointing CallGraphNode at a function that already exists");
+ FunctionMapTy::iterator I = FunctionMap.find(From);
+ I->second->F = const_cast<Function*>(To);
+ FunctionMap[To] = I->second;
+ 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() == M) && "Function not in current module!");
+ return CGN = new CallGraphNode(const_cast<Function*>(F));
+}
+
+void CallGraphNode::print(raw_ostream &OS) const {
+ if (Function *F = getFunction())
+ OS << "Call graph node for function: '" << F->getName() << "'";
+ else
+ OS << "Call graph node <<null function>>";
+
+ OS << "<<" << this << ">> #uses=" << getNumReferences() << '\n';
+
+ for (const_iterator I = begin(), E = end(); I != E; ++I) {
+ OS << " CS<" << I->first << "> calls ";
+ if (Function *FI = I->second->getFunction())
+ OS << "function '" << FI->getName() <<"'\n";
+ else
+ OS << "external node\n";
+ }
+ OS << '\n';
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraphNode::dump() const { print(dbgs()); }
+#endif
-void CallGraphNode::removeCallEdgeTo(CallGraphNode *Callee) {
- for (unsigned i = CalledFunctions.size(); ; --i) {
- assert(i && "Cannot find callee to remove!");
- if (CalledFunctions[i-1] == Callee) {
- CalledFunctions.erase(CalledFunctions.begin()+i-1);
+/// 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 (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+ if (I->first == CS.getInstruction()) {
+ I->second->DropRef();
+ *I = CalledFunctions.back();
+ CalledFunctions.pop_back();
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 (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
+ if (CalledFunctions[i].second == Callee) {
+ Callee->DropRef();
+ CalledFunctions[i] = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ --i; --e;
+ }
+}
+
+/// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite
+/// from this node to the specified callee function.
+void CallGraphNode::removeOneAbstractEdgeTo(CallGraphNode *Callee) {
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
+ CallRecord &CR = *I;
+ if (CR.second == Callee && CR.first == 0) {
+ Callee->DropRef();
+ *I = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ return;
+ }
+ }
+}
+
+/// replaceCallEdge - This method replaces the edge in the node for the
+/// specified call site with a new one. Note that this method takes linear
+/// time, so it should be used sparingly.
+void CallGraphNode::replaceCallEdge(CallSite CS,
+ CallSite NewCS, CallGraphNode *NewNode){
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+ if (I->first == CS.getInstruction()) {
+ I->second->DropRef();
+ I->first = NewCS.getInstruction();
+ I->second = NewNode;
+ NewNode->AddRef();
+ return;
+ }
+ }
+}
+
+// Enuse that users of CallGraph.h also link with this file
+DEFINING_FILE_FOR(CallGraph)
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