AnalysisContext.h revision 453cb859a3c8dcafe79ae840dfc35ff8eae1b4b3
1//=== AnalysisContext.h - Analysis context for Path Sens analysis --*- C++ -*-//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines AnalysisDeclContext, a class that manages the analysis
11// context data for path sensitive analysis.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_ANALYSIS_ANALYSISCONTEXT_H
16#define LLVM_CLANG_ANALYSIS_ANALYSISCONTEXT_H
17
18#include "clang/AST/Decl.h"
19#include "clang/AST/Expr.h"
20#include "clang/Analysis/CFG.h"
21#include "llvm/ADT/DenseMap.h"
22#include "llvm/ADT/FoldingSet.h"
23#include "llvm/ADT/IntrusiveRefCntPtr.h"
24#include "llvm/ADT/OwningPtr.h"
25#include "llvm/ADT/PointerUnion.h"
26#include "llvm/Support/Allocator.h"
27
28namespace clang {
29
30class Decl;
31class Stmt;
32class CFGReverseBlockReachabilityAnalysis;
33class CFGStmtMap;
34class LiveVariables;
35class ManagedAnalysis;
36class ParentMap;
37class PseudoConstantAnalysis;
38class ImplicitParamDecl;
39class LocationContextManager;
40class StackFrameContext;
41class BlockInvocationContext;
42class AnalysisDeclContextManager;
43class LocationContext;
44
45namespace idx { class TranslationUnit; }
46
47/// The base class of a hierarchy of objects representing analyses tied
48/// to AnalysisDeclContext.
49class ManagedAnalysis {
50protected:
51  ManagedAnalysis() {}
52public:
53  virtual ~ManagedAnalysis();
54
55  // Subclasses need to implement:
56  //
57  //  static const void *getTag();
58  //
59  // Which returns a fixed pointer address to distinguish classes of
60  // analysis objects.  They also need to implement:
61  //
62  //  static [Derived*] create(AnalysisDeclContext &Ctx);
63  //
64  // which creates the analysis object given an AnalysisDeclContext.
65};
66
67
68/// AnalysisDeclContext contains the context data for the function or method
69/// under analysis.
70class AnalysisDeclContext {
71  /// Backpoint to the AnalysisManager object that created this
72  /// AnalysisDeclContext. This may be null.
73  AnalysisDeclContextManager *Manager;
74
75  const Decl * const D;
76
77  OwningPtr<CFG> cfg, completeCFG;
78  OwningPtr<CFGStmtMap> cfgStmtMap;
79
80  CFG::BuildOptions cfgBuildOptions;
81  CFG::BuildOptions::ForcedBlkExprs *forcedBlkExprs;
82
83  bool builtCFG, builtCompleteCFG;
84  OwningPtr<ParentMap> PM;
85  OwningPtr<PseudoConstantAnalysis> PCA;
86  OwningPtr<CFGReverseBlockReachabilityAnalysis> CFA;
87
88  llvm::BumpPtrAllocator A;
89
90  llvm::DenseMap<const BlockDecl*,void*> *ReferencedBlockVars;
91
92  void *ManagedAnalyses;
93
94public:
95  AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
96                  const Decl *D);
97
98  AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
99                  const Decl *D,
100                  const CFG::BuildOptions &BuildOptions);
101
102  ~AnalysisDeclContext();
103
104  ASTContext &getASTContext() const { return D->getASTContext(); }
105  const Decl *getDecl() const { return D; }
106
107  /// Return the AnalysisDeclContextManager (if any) that created
108  /// this AnalysisDeclContext.
109  AnalysisDeclContextManager *getManager() const {
110    return Manager;
111  }
112
113  /// Return the build options used to construct the CFG.
114  CFG::BuildOptions &getCFGBuildOptions() {
115    return cfgBuildOptions;
116  }
117
118  const CFG::BuildOptions &getCFGBuildOptions() const {
119    return cfgBuildOptions;
120  }
121
122  /// getAddEHEdges - Return true iff we are adding exceptional edges from
123  /// callExprs.  If this is false, then try/catch statements and blocks
124  /// reachable from them can appear to be dead in the CFG, analysis passes must
125  /// cope with that.
126  bool getAddEHEdges() const { return cfgBuildOptions.AddEHEdges; }
127  bool getUseUnoptimizedCFG() const {
128      return !cfgBuildOptions.PruneTriviallyFalseEdges;
129  }
130  bool getAddImplicitDtors() const { return cfgBuildOptions.AddImplicitDtors; }
131  bool getAddInitializers() const { return cfgBuildOptions.AddInitializers; }
132
133  void registerForcedBlockExpression(const Stmt *stmt);
134  const CFGBlock *getBlockForRegisteredExpression(const Stmt *stmt);
135
136  /// \brief Get the body of the Declaration.
137  Stmt *getBody() const;
138
139  /// \brief Get the body of the Declaration.
140  /// \param IsAutosynthesized Output parameter that specifies if the body is
141  /// auto-generated by the BodyFarm.
142  Stmt *getBody(bool &IsAutosynthesized) const;
143
144  /// \brief Checks if the body of the Decl is generated by the BodyFarm.
145  ///
146  /// Note, the lookup is not free. We are going to call getBody behind
147  /// the sceines.
148  /// \sa getBody
149  bool isBodyAutosynthesized() const;
150
151  CFG *getCFG();
152
153  CFGStmtMap *getCFGStmtMap();
154
155  CFGReverseBlockReachabilityAnalysis *getCFGReachablityAnalysis();
156
157  /// Return a version of the CFG without any edges pruned.
158  CFG *getUnoptimizedCFG();
159
160  void dumpCFG(bool ShowColors);
161
162  /// \brief Returns true if we have built a CFG for this analysis context.
163  /// Note that this doesn't correspond to whether or not a valid CFG exists, it
164  /// corresponds to whether we *attempted* to build one.
165  bool isCFGBuilt() const { return builtCFG; }
166
167  ParentMap &getParentMap();
168  PseudoConstantAnalysis *getPseudoConstantAnalysis();
169
170  typedef const VarDecl * const * referenced_decls_iterator;
171
172  std::pair<referenced_decls_iterator, referenced_decls_iterator>
173    getReferencedBlockVars(const BlockDecl *BD);
174
175  /// Return the ImplicitParamDecl* associated with 'self' if this
176  /// AnalysisDeclContext wraps an ObjCMethodDecl.  Returns NULL otherwise.
177  const ImplicitParamDecl *getSelfDecl() const;
178
179  const StackFrameContext *getStackFrame(LocationContext const *Parent,
180                                         const Stmt *S,
181                                         const CFGBlock *Blk,
182                                         unsigned Idx);
183
184  const BlockInvocationContext *
185  getBlockInvocationContext(const LocationContext *parent,
186                            const BlockDecl *BD,
187                            const void *ContextData);
188
189  /// Return the specified analysis object, lazily running the analysis if
190  /// necessary.  Return NULL if the analysis could not run.
191  template <typename T>
192  T *getAnalysis() {
193    const void *tag = T::getTag();
194    ManagedAnalysis *&data = getAnalysisImpl(tag);
195    if (!data) {
196      data = T::create(*this);
197    }
198    return static_cast<T*>(data);
199  }
200private:
201  ManagedAnalysis *&getAnalysisImpl(const void* tag);
202
203  LocationContextManager &getLocationContextManager();
204};
205
206class LocationContext : public llvm::FoldingSetNode {
207public:
208  enum ContextKind { StackFrame, Scope, Block };
209
210private:
211  ContextKind Kind;
212
213  // AnalysisDeclContext can't be const since some methods may modify its
214  // member.
215  AnalysisDeclContext *Ctx;
216
217  const LocationContext *Parent;
218
219protected:
220  LocationContext(ContextKind k, AnalysisDeclContext *ctx,
221                  const LocationContext *parent)
222    : Kind(k), Ctx(ctx), Parent(parent) {}
223
224public:
225  virtual ~LocationContext();
226
227  ContextKind getKind() const { return Kind; }
228
229  AnalysisDeclContext *getAnalysisDeclContext() const { return Ctx; }
230
231  const LocationContext *getParent() const { return Parent; }
232
233  bool isParentOf(const LocationContext *LC) const;
234
235  const Decl *getDecl() const { return getAnalysisDeclContext()->getDecl(); }
236
237  CFG *getCFG() const { return getAnalysisDeclContext()->getCFG(); }
238
239  template <typename T>
240  T *getAnalysis() const {
241    return getAnalysisDeclContext()->getAnalysis<T>();
242  }
243
244  ParentMap &getParentMap() const {
245    return getAnalysisDeclContext()->getParentMap();
246  }
247
248  const ImplicitParamDecl *getSelfDecl() const {
249    return Ctx->getSelfDecl();
250  }
251
252  const StackFrameContext *getCurrentStackFrame() const;
253
254  /// Return true if the current LocationContext has no caller context.
255  virtual bool inTopFrame() const;
256
257  virtual void Profile(llvm::FoldingSetNodeID &ID) = 0;
258
259public:
260  static void ProfileCommon(llvm::FoldingSetNodeID &ID,
261                            ContextKind ck,
262                            AnalysisDeclContext *ctx,
263                            const LocationContext *parent,
264                            const void *data);
265};
266
267class StackFrameContext : public LocationContext {
268  // The callsite where this stack frame is established.
269  const Stmt *CallSite;
270
271  // The parent block of the callsite.
272  const CFGBlock *Block;
273
274  // The index of the callsite in the CFGBlock.
275  unsigned Index;
276
277  friend class LocationContextManager;
278  StackFrameContext(AnalysisDeclContext *ctx, const LocationContext *parent,
279                    const Stmt *s, const CFGBlock *blk,
280                    unsigned idx)
281    : LocationContext(StackFrame, ctx, parent), CallSite(s),
282      Block(blk), Index(idx) {}
283
284public:
285  ~StackFrameContext() {}
286
287  const Stmt *getCallSite() const { return CallSite; }
288
289  const CFGBlock *getCallSiteBlock() const { return Block; }
290
291  /// Return true if the current LocationContext has no caller context.
292  virtual bool inTopFrame() const { return getParent() == 0;  }
293
294  unsigned getIndex() const { return Index; }
295
296  void Profile(llvm::FoldingSetNodeID &ID);
297
298  static void Profile(llvm::FoldingSetNodeID &ID, AnalysisDeclContext *ctx,
299                      const LocationContext *parent, const Stmt *s,
300                      const CFGBlock *blk, unsigned idx) {
301    ProfileCommon(ID, StackFrame, ctx, parent, s);
302    ID.AddPointer(blk);
303    ID.AddInteger(idx);
304  }
305
306  static bool classof(const LocationContext *Ctx) {
307    return Ctx->getKind() == StackFrame;
308  }
309};
310
311class ScopeContext : public LocationContext {
312  const Stmt *Enter;
313
314  friend class LocationContextManager;
315  ScopeContext(AnalysisDeclContext *ctx, const LocationContext *parent,
316               const Stmt *s)
317    : LocationContext(Scope, ctx, parent), Enter(s) {}
318
319public:
320  ~ScopeContext() {}
321
322  void Profile(llvm::FoldingSetNodeID &ID);
323
324  static void Profile(llvm::FoldingSetNodeID &ID, AnalysisDeclContext *ctx,
325                      const LocationContext *parent, const Stmt *s) {
326    ProfileCommon(ID, Scope, ctx, parent, s);
327  }
328
329  static bool classof(const LocationContext *Ctx) {
330    return Ctx->getKind() == Scope;
331  }
332};
333
334class BlockInvocationContext : public LocationContext {
335  const BlockDecl *BD;
336
337  // FIXME: Come up with a more type-safe way to model context-sensitivity.
338  const void *ContextData;
339
340  friend class LocationContextManager;
341
342  BlockInvocationContext(AnalysisDeclContext *ctx,
343                         const LocationContext *parent,
344                         const BlockDecl *bd, const void *contextData)
345    : LocationContext(Block, ctx, parent), BD(bd), ContextData(contextData) {}
346
347public:
348  ~BlockInvocationContext() {}
349
350  const BlockDecl *getBlockDecl() const { return BD; }
351
352  const void *getContextData() const { return ContextData; }
353
354  void Profile(llvm::FoldingSetNodeID &ID);
355
356  static void Profile(llvm::FoldingSetNodeID &ID, AnalysisDeclContext *ctx,
357                      const LocationContext *parent, const BlockDecl *bd,
358                      const void *contextData) {
359    ProfileCommon(ID, Block, ctx, parent, bd);
360    ID.AddPointer(contextData);
361  }
362
363  static bool classof(const LocationContext *Ctx) {
364    return Ctx->getKind() == Block;
365  }
366};
367
368class LocationContextManager {
369  llvm::FoldingSet<LocationContext> Contexts;
370public:
371  ~LocationContextManager();
372
373  const StackFrameContext *getStackFrame(AnalysisDeclContext *ctx,
374                                         const LocationContext *parent,
375                                         const Stmt *s,
376                                         const CFGBlock *blk, unsigned idx);
377
378  const ScopeContext *getScope(AnalysisDeclContext *ctx,
379                               const LocationContext *parent,
380                               const Stmt *s);
381
382  const BlockInvocationContext *
383  getBlockInvocationContext(AnalysisDeclContext *ctx,
384                            const LocationContext *parent,
385                            const BlockDecl *BD,
386                            const void *ContextData);
387
388  /// Discard all previously created LocationContext objects.
389  void clear();
390private:
391  template <typename LOC, typename DATA>
392  const LOC *getLocationContext(AnalysisDeclContext *ctx,
393                                const LocationContext *parent,
394                                const DATA *d);
395};
396
397class AnalysisDeclContextManager {
398  typedef llvm::DenseMap<const Decl*, AnalysisDeclContext*> ContextMap;
399
400  ContextMap Contexts;
401  LocationContextManager LocContexts;
402  CFG::BuildOptions cfgBuildOptions;
403
404  /// Flag to indicate whether or not bodies should be synthesized
405  /// for well-known functions.
406  bool SynthesizeBodies;
407
408public:
409  AnalysisDeclContextManager(bool useUnoptimizedCFG = false,
410                             bool addImplicitDtors = false,
411                             bool addInitializers = false,
412                             bool addTemporaryDtors = false,
413                             bool synthesizeBodies = false);
414
415  ~AnalysisDeclContextManager();
416
417  AnalysisDeclContext *getContext(const Decl *D);
418
419  bool getUseUnoptimizedCFG() const {
420    return !cfgBuildOptions.PruneTriviallyFalseEdges;
421  }
422
423  CFG::BuildOptions &getCFGBuildOptions() {
424    return cfgBuildOptions;
425  }
426
427  /// Return true if faux bodies should be synthesized for well-known
428  /// functions.
429  bool synthesizeBodies() const { return SynthesizeBodies; }
430
431  const StackFrameContext *getStackFrame(AnalysisDeclContext *Ctx,
432                                         LocationContext const *Parent,
433                                         const Stmt *S,
434                                         const CFGBlock *Blk,
435                                         unsigned Idx) {
436    return LocContexts.getStackFrame(Ctx, Parent, S, Blk, Idx);
437  }
438
439  // Get the top level stack frame.
440  const StackFrameContext *getStackFrame(const Decl *D) {
441    return LocContexts.getStackFrame(getContext(D), 0, 0, 0, 0);
442  }
443
444  // Get a stack frame with parent.
445  StackFrameContext const *getStackFrame(const Decl *D,
446                                         LocationContext const *Parent,
447                                         const Stmt *S,
448                                         const CFGBlock *Blk,
449                                         unsigned Idx) {
450    return LocContexts.getStackFrame(getContext(D), Parent, S, Blk, Idx);
451  }
452
453  /// Discard all previously created AnalysisDeclContexts.
454  void clear();
455
456private:
457  friend class AnalysisDeclContext;
458
459  LocationContextManager &getLocationContextManager() {
460    return LocContexts;
461  }
462};
463
464} // end clang namespace
465#endif
466