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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Checker/ExplodedGraph.cpp')
-rw-r--r-- | contrib/llvm/tools/clang/lib/Checker/ExplodedGraph.cpp | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Checker/ExplodedGraph.cpp b/contrib/llvm/tools/clang/lib/Checker/ExplodedGraph.cpp new file mode 100644 index 0000000..20429b9 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Checker/ExplodedGraph.cpp @@ -0,0 +1,281 @@ +//=-- ExplodedGraph.cpp - Local, Path-Sens. "Exploded Graph" -*- C++ -*------=// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines the template classes ExplodedNode and ExplodedGraph, +// which represent a path-sensitive, intra-procedural "exploded graph." +// +//===----------------------------------------------------------------------===// + +#include "clang/Checker/PathSensitive/ExplodedGraph.h" +#include "clang/Checker/PathSensitive/GRState.h" +#include "clang/AST/Stmt.h" +#include "llvm/ADT/DenseSet.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/SmallVector.h" +#include <vector> + +using namespace clang; + +//===----------------------------------------------------------------------===// +// Node auditing. +//===----------------------------------------------------------------------===// + +// An out of line virtual method to provide a home for the class vtable. +ExplodedNode::Auditor::~Auditor() {} + +#ifndef NDEBUG +static ExplodedNode::Auditor* NodeAuditor = 0; +#endif + +void ExplodedNode::SetAuditor(ExplodedNode::Auditor* A) { +#ifndef NDEBUG + NodeAuditor = A; +#endif +} + +//===----------------------------------------------------------------------===// +// ExplodedNode. +//===----------------------------------------------------------------------===// + +static inline BumpVector<ExplodedNode*>& getVector(void* P) { + return *reinterpret_cast<BumpVector<ExplodedNode*>*>(P); +} + +void ExplodedNode::addPredecessor(ExplodedNode* V, ExplodedGraph &G) { + assert (!V->isSink()); + Preds.addNode(V, G); + V->Succs.addNode(this, G); +#ifndef NDEBUG + if (NodeAuditor) NodeAuditor->AddEdge(V, this); +#endif +} + +void ExplodedNode::NodeGroup::addNode(ExplodedNode* N, ExplodedGraph &G) { + assert((reinterpret_cast<uintptr_t>(N) & Mask) == 0x0); + assert(!getFlag()); + + if (getKind() == Size1) { + if (ExplodedNode* NOld = getNode()) { + BumpVectorContext &Ctx = G.getNodeAllocator(); + BumpVector<ExplodedNode*> *V = + G.getAllocator().Allocate<BumpVector<ExplodedNode*> >(); + new (V) BumpVector<ExplodedNode*>(Ctx, 4); + + assert((reinterpret_cast<uintptr_t>(V) & Mask) == 0x0); + V->push_back(NOld, Ctx); + V->push_back(N, Ctx); + P = reinterpret_cast<uintptr_t>(V) | SizeOther; + assert(getPtr() == (void*) V); + assert(getKind() == SizeOther); + } + else { + P = reinterpret_cast<uintptr_t>(N); + assert(getKind() == Size1); + } + } + else { + assert(getKind() == SizeOther); + getVector(getPtr()).push_back(N, G.getNodeAllocator()); + } +} + +unsigned ExplodedNode::NodeGroup::size() const { + if (getFlag()) + return 0; + + if (getKind() == Size1) + return getNode() ? 1 : 0; + else + return getVector(getPtr()).size(); +} + +ExplodedNode **ExplodedNode::NodeGroup::begin() const { + if (getFlag()) + return NULL; + + if (getKind() == Size1) + return (ExplodedNode**) (getPtr() ? &P : NULL); + else + return const_cast<ExplodedNode**>(&*(getVector(getPtr()).begin())); +} + +ExplodedNode** ExplodedNode::NodeGroup::end() const { + if (getFlag()) + return NULL; + + if (getKind() == Size1) + return (ExplodedNode**) (getPtr() ? &P+1 : NULL); + else { + // Dereferencing end() is undefined behaviour. The vector is not empty, so + // we can dereference the last elem and then add 1 to the result. + return const_cast<ExplodedNode**>(getVector(getPtr()).end()); + } +} + +ExplodedNode *ExplodedGraph::getNode(const ProgramPoint& L, + const GRState* State, bool* IsNew) { + // Profile 'State' to determine if we already have an existing node. + llvm::FoldingSetNodeID profile; + void* InsertPos = 0; + + NodeTy::Profile(profile, L, State); + NodeTy* V = Nodes.FindNodeOrInsertPos(profile, InsertPos); + + if (!V) { + // Allocate a new node. + V = (NodeTy*) getAllocator().Allocate<NodeTy>(); + new (V) NodeTy(L, State); + + // Insert the node into the node set and return it. + Nodes.InsertNode(V, InsertPos); + + ++NumNodes; + + if (IsNew) *IsNew = true; + } + else + if (IsNew) *IsNew = false; + + return V; +} + +std::pair<ExplodedGraph*, InterExplodedGraphMap*> +ExplodedGraph::Trim(const NodeTy* const* NBeg, const NodeTy* const* NEnd, + llvm::DenseMap<const void*, const void*> *InverseMap) const { + + if (NBeg == NEnd) + return std::make_pair((ExplodedGraph*) 0, + (InterExplodedGraphMap*) 0); + + assert (NBeg < NEnd); + + llvm::OwningPtr<InterExplodedGraphMap> M(new InterExplodedGraphMap()); + + ExplodedGraph* G = TrimInternal(NBeg, NEnd, M.get(), InverseMap); + + return std::make_pair(static_cast<ExplodedGraph*>(G), M.take()); +} + +ExplodedGraph* +ExplodedGraph::TrimInternal(const ExplodedNode* const* BeginSources, + const ExplodedNode* const* EndSources, + InterExplodedGraphMap* M, + llvm::DenseMap<const void*, const void*> *InverseMap) const { + + typedef llvm::DenseSet<const ExplodedNode*> Pass1Ty; + Pass1Ty Pass1; + + typedef llvm::DenseMap<const ExplodedNode*, ExplodedNode*> Pass2Ty; + Pass2Ty& Pass2 = M->M; + + llvm::SmallVector<const ExplodedNode*, 10> WL1, WL2; + + // ===- Pass 1 (reverse DFS) -=== + for (const ExplodedNode* const* I = BeginSources; I != EndSources; ++I) { + assert(*I); + WL1.push_back(*I); + } + + // Process the first worklist until it is empty. Because it is a std::list + // it acts like a FIFO queue. + while (!WL1.empty()) { + const ExplodedNode *N = WL1.back(); + WL1.pop_back(); + + // Have we already visited this node? If so, continue to the next one. + if (Pass1.count(N)) + continue; + + // Otherwise, mark this node as visited. + Pass1.insert(N); + + // If this is a root enqueue it to the second worklist. + if (N->Preds.empty()) { + WL2.push_back(N); + continue; + } + + // Visit our predecessors and enqueue them. + for (ExplodedNode** I=N->Preds.begin(), **E=N->Preds.end(); I!=E; ++I) + WL1.push_back(*I); + } + + // We didn't hit a root? Return with a null pointer for the new graph. + if (WL2.empty()) + return 0; + + // Create an empty graph. + ExplodedGraph* G = MakeEmptyGraph(); + + // ===- Pass 2 (forward DFS to construct the new graph) -=== + while (!WL2.empty()) { + const ExplodedNode* N = WL2.back(); + WL2.pop_back(); + + // Skip this node if we have already processed it. + if (Pass2.find(N) != Pass2.end()) + continue; + + // Create the corresponding node in the new graph and record the mapping + // from the old node to the new node. + ExplodedNode* NewN = G->getNode(N->getLocation(), N->State, NULL); + Pass2[N] = NewN; + + // Also record the reverse mapping from the new node to the old node. + if (InverseMap) (*InverseMap)[NewN] = N; + + // If this node is a root, designate it as such in the graph. + if (N->Preds.empty()) + G->addRoot(NewN); + + // In the case that some of the intended predecessors of NewN have already + // been created, we should hook them up as predecessors. + + // Walk through the predecessors of 'N' and hook up their corresponding + // nodes in the new graph (if any) to the freshly created node. + for (ExplodedNode **I=N->Preds.begin(), **E=N->Preds.end(); I!=E; ++I) { + Pass2Ty::iterator PI = Pass2.find(*I); + if (PI == Pass2.end()) + continue; + + NewN->addPredecessor(PI->second, *G); + } + + // In the case that some of the intended successors of NewN have already + // been created, we should hook them up as successors. Otherwise, enqueue + // the new nodes from the original graph that should have nodes created + // in the new graph. + for (ExplodedNode **I=N->Succs.begin(), **E=N->Succs.end(); I!=E; ++I) { + Pass2Ty::iterator PI = Pass2.find(*I); + if (PI != Pass2.end()) { + PI->second->addPredecessor(NewN, *G); + continue; + } + + // Enqueue nodes to the worklist that were marked during pass 1. + if (Pass1.count(*I)) + WL2.push_back(*I); + } + + // Finally, explictly mark all nodes without any successors as sinks. + if (N->isSink()) + NewN->markAsSink(); + } + + return G; +} + +ExplodedNode* +InterExplodedGraphMap::getMappedNode(const ExplodedNode* N) const { + llvm::DenseMap<const ExplodedNode*, ExplodedNode*>::const_iterator I = + M.find(N); + + return I == M.end() ? 0 : I->second; +} + |