//===- Local.cpp - Compute a local data structure graph for a function ----===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
//
// Compute the local version of the data structure graph for a function. The
// external interface to this file is the DSGraph constructor.
#include "llvm/Analysis/DSGraph.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Target/TargetData.h"
X("datastructure", "Local Data Structure Analysis");
namespace DS {
- // FIXME: Do something smarter with target data!
- TargetData TD("temp-td");
-
// isPointerType - Return true if this type is big enough to hold a pointer.
bool isPointerType(const Type *Ty) {
if (isa<PointerType>(Ty))
/// graph by performing a single pass over the function in question.
///
class GraphBuilder : InstVisitor<GraphBuilder> {
- Function &F;
DSGraph &G;
- DSNodeHandle &RetNode; // Node that gets returned...
+ DSNodeHandle *RetNode; // Node that gets returned...
DSGraph::ScalarMapTy &ScalarMap;
- std::vector<DSCallSite> &FunctionCalls;
+ std::vector<DSCallSite> *FunctionCalls;
public:
GraphBuilder(Function &f, DSGraph &g, DSNodeHandle &retNode,
- DSGraph::ScalarMapTy &SM, std::vector<DSCallSite> &fc)
- : F(f), G(g), RetNode(retNode), ScalarMap(SM),
- FunctionCalls(fc) {
+ std::vector<DSCallSite> &fc)
+ : G(g), RetNode(&retNode), ScalarMap(G.getScalarMap()),
+ FunctionCalls(&fc) {
// Create scalar nodes for all pointer arguments...
- for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
+ for (Function::aiterator I = f.abegin(), E = f.aend(); I != E; ++I)
if (isPointerType(I->getType()))
getValueDest(*I);
- visit(F); // Single pass over the function
+ visit(f); // Single pass over the function
+ }
+
+ // GraphBuilder ctor for working on the globals graph
+ GraphBuilder(DSGraph &g)
+ : G(g), RetNode(0), ScalarMap(G.getScalarMap()), FunctionCalls(0) {
}
+ void mergeInGlobalInitializer(GlobalVariable *GV);
+
private:
// Visitor functions, used to handle each instruction type we encounter...
friend class InstVisitor<GraphBuilder>;
void visitInstruction(Instruction &I);
void visitCallSite(CallSite CS);
+
+ void MergeConstantInitIntoNode(DSNodeHandle &NH, Constant *C);
private:
// Helper functions used to implement the visitation functions...
//===----------------------------------------------------------------------===//
// DSGraph constructor - Simply use the GraphBuilder to construct the local
// graph.
-DSGraph::DSGraph(Function &F, DSGraph *GG) : GlobalsGraph(GG) {
+DSGraph::DSGraph(const TargetData &td, Function &F, DSGraph *GG)
+ : GlobalsGraph(GG), TD(td) {
PrintAuxCalls = false;
DEBUG(std::cerr << " [Loc] Calculating graph for: " << F.getName() << "\n");
// Use the graph builder to construct the local version of the graph
- GraphBuilder B(F, *this, ReturnNodes[&F], ScalarMap, FunctionCalls);
+ GraphBuilder B(F, *this, ReturnNodes[&F], FunctionCalls);
#ifndef NDEBUG
Timer::addPeakMemoryMeasurement();
#endif
DSNodeHandle Value = getValueDest(*GEP.getOperand(0));
if (Value.getNode() == 0) return;
- unsigned Offset = 0;
const PointerType *PTy = cast<PointerType>(GEP.getOperand(0)->getType());
const Type *CurTy = PTy->getElementType();
return;
}
+ const TargetData &TD = Value.getNode()->getTargetData();
+
#if 0
// Handle the pointer index specially...
if (GEP.getNumOperands() > 1 &&
#endif
// All of these subscripts are indexing INTO the elements we have...
+ unsigned Offset = 0;
for (unsigned i = 2, e = GEP.getNumOperands(); i < e; ++i)
if (GEP.getOperand(i)->getType() == Type::LongTy) {
// Get the type indexing into...
// Mark that the node is written to...
Dest.getNode()->setModifiedMarker();
- // Ensure a typerecord exists...
+ // Ensure a type-record exists...
Dest.getNode()->mergeTypeInfo(StoredTy, Dest.getOffset());
// Avoid adding edges from null, or processing non-"pointer" stores
void GraphBuilder::visitReturnInst(ReturnInst &RI) {
if (RI.getNumOperands() && isPointerType(RI.getOperand(0)->getType()))
- RetNode.mergeWith(getValueDest(*RI.getOperand(0)));
+ RetNode->mergeWith(getValueDest(*RI.getOperand(0)));
}
void GraphBuilder::visitCallInst(CallInst &CI) {
}
void GraphBuilder::visitCallSite(CallSite CS) {
+ // Special case handling of certain libc allocation functions here.
+ if (Function *F = CS.getCalledFunction())
+ if (F->isExternal())
+ if (F->getName() == "calloc") {
+ setDestTo(*CS.getInstruction(),
+ createNode()->setHeapNodeMarker()->setModifiedMarker());
+ return;
+ } else if (F->getName() == "realloc") {
+ DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
+ RetNH.mergeWith(getValueDest(**CS.arg_begin()));
+ if (DSNode *N = RetNH.getNode())
+ N->setHeapNodeMarker()->setModifiedMarker()->setReadMarker();
+ return;
+ } else if (F->getName() == "memset") {
+ // Merge the first argument with the return value, and mark the memory
+ // modified.
+ DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
+ RetNH.mergeWith(getValueDest(**CS.arg_begin()));
+ if (DSNode *N = RetNH.getNode())
+ N->setModifiedMarker();
+ return;
+ } else if (F->getName() == "memmove") {
+ // Merge the first & second arguments with the result, and mark the
+ // memory read and modified.
+ DSNodeHandle RetNH = getValueDest(*CS.getInstruction());
+ RetNH.mergeWith(getValueDest(**CS.arg_begin()));
+ RetNH.mergeWith(getValueDest(**(CS.arg_begin()+1)));
+ if (DSNode *N = RetNH.getNode())
+ N->setModifiedMarker()->setReadMarker();
+ return;
+ } else if (F->getName() == "bzero") {
+ // Mark the memory modified.
+ DSNodeHandle H = getValueDest(**CS.arg_begin());
+ if (DSNode *N = H.getNode())
+ N->setModifiedMarker();
+ return;
+ }
+
+
// Set up the return value...
DSNodeHandle RetVal;
Instruction *I = CS.getInstruction();
RetVal = getValueDest(*I);
DSNode *Callee = 0;
- if (DisableDirectCallOpt || !isa<Function>(CS.getCalledValue()))
+ if (DisableDirectCallOpt || !isa<Function>(CS.getCalledValue())) {
Callee = getValueDest(*CS.getCalledValue()).getNode();
+ if (Callee == 0) {
+ std::cerr << "WARNING: Program is calling through a null pointer?\n"
+ << *I;
+ return; // Calling a null pointer?
+ }
+ }
std::vector<DSNodeHandle> Args;
Args.reserve(CS.arg_end()-CS.arg_begin());
// Add a new function call entry...
if (Callee)
- FunctionCalls.push_back(DSCallSite(CS, RetVal, Callee, Args));
+ FunctionCalls->push_back(DSCallSite(CS, RetVal, Callee, Args));
else
- FunctionCalls.push_back(DSCallSite(CS, RetVal, CS.getCalledFunction(),
- Args));
+ FunctionCalls->push_back(DSCallSite(CS, RetVal, CS.getCalledFunction(),
+ Args));
}
void GraphBuilder::visitFreeInst(FreeInst &FI) {
// LocalDataStructures Implementation
//===----------------------------------------------------------------------===//
+// MergeConstantInitIntoNode - Merge the specified constant into the node
+// pointed to by NH.
+void GraphBuilder::MergeConstantInitIntoNode(DSNodeHandle &NH, Constant *C) {
+ // Ensure a type-record exists...
+ NH.getNode()->mergeTypeInfo(C->getType(), NH.getOffset());
+
+ if (C->getType()->isFirstClassType()) {
+ if (isPointerType(C->getType()))
+ // Avoid adding edges from null, or processing non-"pointer" stores
+ NH.addEdgeTo(getValueDest(*C));
+ return;
+ }
+
+ const TargetData &TD = NH.getNode()->getTargetData();
+
+ if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
+ for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
+ // We don't currently do any indexing for arrays...
+ MergeConstantInitIntoNode(NH, cast<Constant>(CA->getOperand(i)));
+ } else if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
+ const StructLayout *SL = TD.getStructLayout(CS->getType());
+ for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
+ DSNodeHandle NewNH(NH.getNode(), NH.getOffset()+SL->MemberOffsets[i]);
+ MergeConstantInitIntoNode(NewNH, cast<Constant>(CS->getOperand(i)));
+ }
+ } else {
+ assert(0 && "Unknown constant type!");
+ }
+}
+
+void GraphBuilder::mergeInGlobalInitializer(GlobalVariable *GV) {
+ assert(!GV->isExternal() && "Cannot merge in external global!");
+ // Get a node handle to the global node and merge the initializer into it.
+ DSNodeHandle NH = getValueDest(*GV);
+ MergeConstantInitIntoNode(NH, GV->getInitializer());
+}
+
+
bool LocalDataStructures::run(Module &M) {
- GlobalsGraph = new DSGraph();
+ GlobalsGraph = new DSGraph(getAnalysis<TargetData>());
+
+ const TargetData &TD = getAnalysis<TargetData>();
// Calculate all of the graphs...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isExternal())
- DSInfo.insert(std::make_pair(I, new DSGraph(*I, GlobalsGraph)));
+ DSInfo.insert(std::make_pair(I, new DSGraph(TD, *I, GlobalsGraph)));
+
+ GraphBuilder GGB(*GlobalsGraph);
+
+ // Add initializers for all of the globals to the globals graph...
+ for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
+ if (!I->isExternal())
+ GGB.mergeInGlobalInitializer(I);
+
+ GlobalsGraph->markIncompleteNodes(DSGraph::MarkFormalArgs);
+ GlobalsGraph->removeTriviallyDeadNodes();
return false;
}