ExplodedGraph.h revision 226633
144963Sjb//=-- ExplodedGraph.h - Local, Path-Sens. "Exploded Graph" -*- C++ -*-------==// 244963Sjb// 344963Sjb// The LLVM Compiler Infrastructure 444963Sjb// 544963Sjb// This file is distributed under the University of Illinois Open Source 644963Sjb// License. See LICENSE.TXT for details. 744963Sjb// 844963Sjb//===----------------------------------------------------------------------===// 944963Sjb// 1044963Sjb// This file defines the template classes ExplodedNode and ExplodedGraph, 1144963Sjb// which represent a path-sensitive, intra-procedural "exploded graph." 1244963Sjb// See "Precise interprocedural dataflow analysis via graph reachability" 1344963Sjb// by Reps, Horwitz, and Sagiv 1444963Sjb// (http://portal.acm.org/citation.cfm?id=199462) for the definition of an 1544963Sjb// exploded graph. 1644963Sjb// 1744963Sjb//===----------------------------------------------------------------------===// 1844963Sjb 1944963Sjb#ifndef LLVM_CLANG_GR_EXPLODEDGRAPH 2044963Sjb#define LLVM_CLANG_GR_EXPLODEDGRAPH 2144963Sjb 2244963Sjb#include "clang/Analysis/ProgramPoint.h" 2344963Sjb#include "clang/Analysis/AnalysisContext.h" 2444963Sjb#include "clang/AST/Decl.h" 2544963Sjb#include "llvm/ADT/SmallVector.h" 2644963Sjb#include "llvm/ADT/FoldingSet.h" 2744963Sjb#include "llvm/ADT/SmallPtrSet.h" 2844963Sjb#include "llvm/Support/Allocator.h" 2944963Sjb#include "llvm/ADT/OwningPtr.h" 3044963Sjb#include "llvm/ADT/GraphTraits.h" 3144963Sjb#include "llvm/ADT/DepthFirstIterator.h" 3250476Speter#include "llvm/Support/Casting.h" 3344963Sjb#include "clang/Analysis/Support/BumpVector.h" 34174112Sdeischen#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 35174112Sdeischen 3644963Sjbnamespace clang { 3744963Sjb 3844963Sjbclass CFG; 39174112Sdeischen 40103388Smininamespace ento { 4144963Sjb 42156611Sdeischenclass ExplodedGraph; 43156611Sdeischen 44156611Sdeischen//===----------------------------------------------------------------------===// 45156611Sdeischen// ExplodedGraph "implementation" classes. These classes are not typed to 4644963Sjb// contain a specific kind of state. Typed-specialized versions are defined 4775369Sdeischen// on top of these classes. 4875369Sdeischen//===----------------------------------------------------------------------===// 4971581Sdeischen 5044963Sjb// ExplodedNode is not constified all over the engine because we need to add 51174112Sdeischen// successors to it at any time after creating it. 5244963Sjb 53113658Sdeischenclass ExplodedNode : public llvm::FoldingSetNode { 5444963Sjb friend class ExplodedGraph; 5544963Sjb friend class CoreEngine; 5644963Sjb friend class StmtNodeBuilder; 57174112Sdeischen friend class BranchNodeBuilder; 5844963Sjb friend class IndirectGotoNodeBuilder; 59113658Sdeischen friend class SwitchNodeBuilder; 6044963Sjb friend class EndOfFunctionNodeBuilder; 61 62 class NodeGroup { 63 enum { Size1 = 0x0, SizeOther = 0x1, AuxFlag = 0x2, Mask = 0x3 }; 64 uintptr_t P; 65 66 unsigned getKind() const { 67 return P & 0x1; 68 } 69 70 void *getPtr() const { 71 assert (!getFlag()); 72 return reinterpret_cast<void*>(P & ~Mask); 73 } 74 75 ExplodedNode *getNode() const { 76 return reinterpret_cast<ExplodedNode*>(getPtr()); 77 } 78 79 public: 80 NodeGroup() : P(0) {} 81 82 ExplodedNode **begin() const; 83 84 ExplodedNode **end() const; 85 86 unsigned size() const; 87 88 bool empty() const { return (P & ~Mask) == 0; } 89 90 void addNode(ExplodedNode *N, ExplodedGraph &G); 91 92 void replaceNode(ExplodedNode *node); 93 94 void setFlag() { 95 assert(P == 0); 96 P = AuxFlag; 97 } 98 99 bool getFlag() const { 100 return P & AuxFlag ? true : false; 101 } 102 }; 103 104 /// Location - The program location (within a function body) associated 105 /// with this node. 106 const ProgramPoint Location; 107 108 /// State - The state associated with this node. 109 const ProgramState *State; 110 111 /// Preds - The predecessors of this node. 112 NodeGroup Preds; 113 114 /// Succs - The successors of this node. 115 NodeGroup Succs; 116 117public: 118 119 explicit ExplodedNode(const ProgramPoint &loc, const ProgramState *state) 120 : Location(loc), State(state) { 121 const_cast<ProgramState*>(State)->incrementReferenceCount(); 122 } 123 124 ~ExplodedNode() { 125 const_cast<ProgramState*>(State)->decrementReferenceCount(); 126 } 127 128 /// getLocation - Returns the edge associated with the given node. 129 ProgramPoint getLocation() const { return Location; } 130 131 const LocationContext *getLocationContext() const { 132 return getLocation().getLocationContext(); 133 } 134 135 const Decl &getCodeDecl() const { return *getLocationContext()->getDecl(); } 136 137 CFG &getCFG() const { return *getLocationContext()->getCFG(); } 138 139 ParentMap &getParentMap() const {return getLocationContext()->getParentMap();} 140 141 template <typename T> 142 T &getAnalysis() const { 143 return *getLocationContext()->getAnalysis<T>(); 144 } 145 146 const ProgramState *getState() const { return State; } 147 148 template <typename T> 149 const T* getLocationAs() const { return llvm::dyn_cast<T>(&Location); } 150 151 static void Profile(llvm::FoldingSetNodeID &ID, 152 const ProgramPoint &Loc, const ProgramState *state) { 153 ID.Add(Loc); 154 ID.AddPointer(state); 155 } 156 157 void Profile(llvm::FoldingSetNodeID& ID) const { 158 Profile(ID, getLocation(), getState()); 159 } 160 161 /// addPredeccessor - Adds a predecessor to the current node, and 162 /// in tandem add this node as a successor of the other node. 163 void addPredecessor(ExplodedNode *V, ExplodedGraph &G); 164 165 unsigned succ_size() const { return Succs.size(); } 166 unsigned pred_size() const { return Preds.size(); } 167 bool succ_empty() const { return Succs.empty(); } 168 bool pred_empty() const { return Preds.empty(); } 169 170 bool isSink() const { return Succs.getFlag(); } 171 void markAsSink() { Succs.setFlag(); } 172 173 ExplodedNode *getFirstPred() { 174 return pred_empty() ? NULL : *(pred_begin()); 175 } 176 177 const ExplodedNode *getFirstPred() const { 178 return const_cast<ExplodedNode*>(this)->getFirstPred(); 179 } 180 181 // Iterators over successor and predecessor vertices. 182 typedef ExplodedNode** succ_iterator; 183 typedef const ExplodedNode* const * const_succ_iterator; 184 typedef ExplodedNode** pred_iterator; 185 typedef const ExplodedNode* const * const_pred_iterator; 186 187 pred_iterator pred_begin() { return Preds.begin(); } 188 pred_iterator pred_end() { return Preds.end(); } 189 190 const_pred_iterator pred_begin() const { 191 return const_cast<ExplodedNode*>(this)->pred_begin(); 192 } 193 const_pred_iterator pred_end() const { 194 return const_cast<ExplodedNode*>(this)->pred_end(); 195 } 196 197 succ_iterator succ_begin() { return Succs.begin(); } 198 succ_iterator succ_end() { return Succs.end(); } 199 200 const_succ_iterator succ_begin() const { 201 return const_cast<ExplodedNode*>(this)->succ_begin(); 202 } 203 const_succ_iterator succ_end() const { 204 return const_cast<ExplodedNode*>(this)->succ_end(); 205 } 206 207 // For debugging. 208 209public: 210 211 class Auditor { 212 public: 213 virtual ~Auditor(); 214 virtual void AddEdge(ExplodedNode *Src, ExplodedNode *Dst) = 0; 215 }; 216 217 static void SetAuditor(Auditor* A); 218 219private: 220 void replaceSuccessor(ExplodedNode *node) { Succs.replaceNode(node); } 221 void replacePredecessor(ExplodedNode *node) { Preds.replaceNode(node); } 222}; 223 224// FIXME: Is this class necessary? 225class InterExplodedGraphMap { 226 llvm::DenseMap<const ExplodedNode*, ExplodedNode*> M; 227 friend class ExplodedGraph; 228 229public: 230 ExplodedNode *getMappedNode(const ExplodedNode *N) const; 231 232 InterExplodedGraphMap() {} 233 virtual ~InterExplodedGraphMap() {} 234}; 235 236class ExplodedGraph { 237protected: 238 friend class CoreEngine; 239 240 // Type definitions. 241 typedef SmallVector<ExplodedNode*,2> RootsTy; 242 typedef SmallVector<ExplodedNode*,10> EndNodesTy; 243 244 /// Roots - The roots of the simulation graph. Usually there will be only 245 /// one, but clients are free to establish multiple subgraphs within a single 246 /// SimulGraph. Moreover, these subgraphs can often merge when paths from 247 /// different roots reach the same state at the same program location. 248 RootsTy Roots; 249 250 /// EndNodes - The nodes in the simulation graph which have been 251 /// specially marked as the endpoint of an abstract simulation path. 252 EndNodesTy EndNodes; 253 254 /// Nodes - The nodes in the graph. 255 llvm::FoldingSet<ExplodedNode> Nodes; 256 257 /// BVC - Allocator and context for allocating nodes and their predecessor 258 /// and successor groups. 259 BumpVectorContext BVC; 260 261 /// NumNodes - The number of nodes in the graph. 262 unsigned NumNodes; 263 264 /// A list of recently allocated nodes that can potentially be recycled. 265 void *recentlyAllocatedNodes; 266 267 /// A list of nodes that can be reused. 268 void *freeNodes; 269 270 /// A flag that indicates whether nodes should be recycled. 271 bool reclaimNodes; 272 273public: 274 /// getNode - Retrieve the node associated with a (Location,State) pair, 275 /// where the 'Location' is a ProgramPoint in the CFG. If no node for 276 /// this pair exists, it is created. IsNew is set to true if 277 /// the node was freshly created. 278 279 ExplodedNode *getNode(const ProgramPoint &L, const ProgramState *State, 280 bool* IsNew = 0); 281 282 ExplodedGraph* MakeEmptyGraph() const { 283 return new ExplodedGraph(); 284 } 285 286 /// addRoot - Add an untyped node to the set of roots. 287 ExplodedNode *addRoot(ExplodedNode *V) { 288 Roots.push_back(V); 289 return V; 290 } 291 292 /// addEndOfPath - Add an untyped node to the set of EOP nodes. 293 ExplodedNode *addEndOfPath(ExplodedNode *V) { 294 EndNodes.push_back(V); 295 return V; 296 } 297 298 ExplodedGraph() 299 : NumNodes(0), recentlyAllocatedNodes(0), 300 freeNodes(0), reclaimNodes(false) {} 301 302 ~ExplodedGraph(); 303 304 unsigned num_roots() const { return Roots.size(); } 305 unsigned num_eops() const { return EndNodes.size(); } 306 307 bool empty() const { return NumNodes == 0; } 308 unsigned size() const { return NumNodes; } 309 310 // Iterators. 311 typedef ExplodedNode NodeTy; 312 typedef llvm::FoldingSet<ExplodedNode> AllNodesTy; 313 typedef NodeTy** roots_iterator; 314 typedef NodeTy* const * const_roots_iterator; 315 typedef NodeTy** eop_iterator; 316 typedef NodeTy* const * const_eop_iterator; 317 typedef AllNodesTy::iterator node_iterator; 318 typedef AllNodesTy::const_iterator const_node_iterator; 319 320 node_iterator nodes_begin() { return Nodes.begin(); } 321 322 node_iterator nodes_end() { return Nodes.end(); } 323 324 const_node_iterator nodes_begin() const { return Nodes.begin(); } 325 326 const_node_iterator nodes_end() const { return Nodes.end(); } 327 328 roots_iterator roots_begin() { return Roots.begin(); } 329 330 roots_iterator roots_end() { return Roots.end(); } 331 332 const_roots_iterator roots_begin() const { return Roots.begin(); } 333 334 const_roots_iterator roots_end() const { return Roots.end(); } 335 336 eop_iterator eop_begin() { return EndNodes.begin(); } 337 338 eop_iterator eop_end() { return EndNodes.end(); } 339 340 const_eop_iterator eop_begin() const { return EndNodes.begin(); } 341 342 const_eop_iterator eop_end() const { return EndNodes.end(); } 343 344 llvm::BumpPtrAllocator & getAllocator() { return BVC.getAllocator(); } 345 BumpVectorContext &getNodeAllocator() { return BVC; } 346 347 typedef llvm::DenseMap<const ExplodedNode*, ExplodedNode*> NodeMap; 348 349 std::pair<ExplodedGraph*, InterExplodedGraphMap*> 350 Trim(const NodeTy* const* NBeg, const NodeTy* const* NEnd, 351 llvm::DenseMap<const void*, const void*> *InverseMap = 0) const; 352 353 ExplodedGraph* TrimInternal(const ExplodedNode* const * NBeg, 354 const ExplodedNode* const * NEnd, 355 InterExplodedGraphMap *M, 356 llvm::DenseMap<const void*, const void*> *InverseMap) const; 357 358 /// Enable tracking of recently allocated nodes for potential reclamation 359 /// when calling reclaimRecentlyAllocatedNodes(). 360 void enableNodeReclamation() { reclaimNodes = true; } 361 362 /// Reclaim "uninteresting" nodes created since the last time this method 363 /// was called. 364 void reclaimRecentlyAllocatedNodes(); 365}; 366 367class ExplodedNodeSet { 368 typedef llvm::SmallPtrSet<ExplodedNode*,5> ImplTy; 369 ImplTy Impl; 370 371public: 372 ExplodedNodeSet(ExplodedNode *N) { 373 assert (N && !static_cast<ExplodedNode*>(N)->isSink()); 374 Impl.insert(N); 375 } 376 377 ExplodedNodeSet() {} 378 379 inline void Add(ExplodedNode *N) { 380 if (N && !static_cast<ExplodedNode*>(N)->isSink()) Impl.insert(N); 381 } 382 383 ExplodedNodeSet &operator=(const ExplodedNodeSet &X) { 384 Impl = X.Impl; 385 return *this; 386 } 387 388 typedef ImplTy::iterator iterator; 389 typedef ImplTy::const_iterator const_iterator; 390 391 unsigned size() const { return Impl.size(); } 392 bool empty() const { return Impl.empty(); } 393 394 void clear() { Impl.clear(); } 395 void insert(const ExplodedNodeSet &S) { 396 if (empty()) 397 Impl = S.Impl; 398 else 399 Impl.insert(S.begin(), S.end()); 400 } 401 402 inline iterator begin() { return Impl.begin(); } 403 inline iterator end() { return Impl.end(); } 404 405 inline const_iterator begin() const { return Impl.begin(); } 406 inline const_iterator end() const { return Impl.end(); } 407}; 408 409} // end GR namespace 410 411} // end clang namespace 412 413// GraphTraits 414 415namespace llvm { 416 template<> struct GraphTraits<clang::ento::ExplodedNode*> { 417 typedef clang::ento::ExplodedNode NodeType; 418 typedef NodeType::succ_iterator ChildIteratorType; 419 typedef llvm::df_iterator<NodeType*> nodes_iterator; 420 421 static inline NodeType* getEntryNode(NodeType* N) { 422 return N; 423 } 424 425 static inline ChildIteratorType child_begin(NodeType* N) { 426 return N->succ_begin(); 427 } 428 429 static inline ChildIteratorType child_end(NodeType* N) { 430 return N->succ_end(); 431 } 432 433 static inline nodes_iterator nodes_begin(NodeType* N) { 434 return df_begin(N); 435 } 436 437 static inline nodes_iterator nodes_end(NodeType* N) { 438 return df_end(N); 439 } 440 }; 441 442 template<> struct GraphTraits<const clang::ento::ExplodedNode*> { 443 typedef const clang::ento::ExplodedNode NodeType; 444 typedef NodeType::const_succ_iterator ChildIteratorType; 445 typedef llvm::df_iterator<NodeType*> nodes_iterator; 446 447 static inline NodeType* getEntryNode(NodeType* N) { 448 return N; 449 } 450 451 static inline ChildIteratorType child_begin(NodeType* N) { 452 return N->succ_begin(); 453 } 454 455 static inline ChildIteratorType child_end(NodeType* N) { 456 return N->succ_end(); 457 } 458 459 static inline nodes_iterator nodes_begin(NodeType* N) { 460 return df_begin(N); 461 } 462 463 static inline nodes_iterator nodes_end(NodeType* N) { 464 return df_end(N); 465 } 466 }; 467 468} // end llvm namespace 469 470#endif 471