1 //== AnalysisDeclContext.cpp - 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 context
11 // data for path sensitive analysis.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/DeclTemplate.h"
19 #include "clang/AST/ParentMap.h"
20 #include "clang/AST/StmtVisitor.h"
21 #include "clang/Analysis/Analyses/LiveVariables.h"
22 #include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
23 #include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
24 #include "clang/Analysis/AnalysisContext.h"
25 #include "clang/Analysis/CFG.h"
26 #include "clang/Analysis/CFGStmtMap.h"
27 #include "clang/Analysis/Support/BumpVector.h"
28 #include "llvm/Support/SaveAndRestore.h"
29 #include "llvm/ADT/SmallPtrSet.h"
30 #include "llvm/Support/ErrorHandling.h"
31
32 using namespace clang;
33
34 typedef llvm::DenseMap<const void *, ManagedAnalysis *> ManagedAnalysisMap;
35
AnalysisDeclContext(AnalysisDeclContextManager * Mgr,const Decl * d,const CFG::BuildOptions & buildOptions)36 AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
37 const Decl *d,
38 const CFG::BuildOptions &buildOptions)
39 : Manager(Mgr),
40 D(d),
41 cfgBuildOptions(buildOptions),
42 forcedBlkExprs(0),
43 builtCFG(false),
44 builtCompleteCFG(false),
45 ReferencedBlockVars(0),
46 ManagedAnalyses(0)
47 {
48 cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
49 }
50
AnalysisDeclContext(AnalysisDeclContextManager * Mgr,const Decl * d)51 AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
52 const Decl *d)
53 : Manager(Mgr),
54 D(d),
55 forcedBlkExprs(0),
56 builtCFG(false),
57 builtCompleteCFG(false),
58 ReferencedBlockVars(0),
59 ManagedAnalyses(0)
60 {
61 cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
62 }
63
AnalysisDeclContextManager(bool useUnoptimizedCFG,bool addImplicitDtors,bool addInitializers,bool addTemporaryDtors)64 AnalysisDeclContextManager::AnalysisDeclContextManager(bool useUnoptimizedCFG,
65 bool addImplicitDtors,
66 bool addInitializers,
67 bool addTemporaryDtors) {
68 cfgBuildOptions.PruneTriviallyFalseEdges = !useUnoptimizedCFG;
69 cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
70 cfgBuildOptions.AddInitializers = addInitializers;
71 cfgBuildOptions.AddTemporaryDtors = addTemporaryDtors;
72 }
73
clear()74 void AnalysisDeclContextManager::clear() {
75 for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
76 delete I->second;
77 Contexts.clear();
78 }
79
getBody() const80 Stmt *AnalysisDeclContext::getBody() const {
81 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
82 return FD->getBody();
83 else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
84 return MD->getBody();
85 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
86 return BD->getBody();
87 else if (const FunctionTemplateDecl *FunTmpl
88 = dyn_cast_or_null<FunctionTemplateDecl>(D))
89 return FunTmpl->getTemplatedDecl()->getBody();
90
91 llvm_unreachable("unknown code decl");
92 }
93
getSelfDecl() const94 const ImplicitParamDecl *AnalysisDeclContext::getSelfDecl() const {
95 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
96 return MD->getSelfDecl();
97 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
98 // See if 'self' was captured by the block.
99 for (BlockDecl::capture_const_iterator it = BD->capture_begin(),
100 et = BD->capture_end(); it != et; ++it) {
101 const VarDecl *VD = it->getVariable();
102 if (VD->getName() == "self")
103 return dyn_cast<ImplicitParamDecl>(VD);
104 }
105 }
106
107 return NULL;
108 }
109
registerForcedBlockExpression(const Stmt * stmt)110 void AnalysisDeclContext::registerForcedBlockExpression(const Stmt *stmt) {
111 if (!forcedBlkExprs)
112 forcedBlkExprs = new CFG::BuildOptions::ForcedBlkExprs();
113 // Default construct an entry for 'stmt'.
114 if (const Expr *e = dyn_cast<Expr>(stmt))
115 stmt = e->IgnoreParens();
116 (void) (*forcedBlkExprs)[stmt];
117 }
118
119 const CFGBlock *
getBlockForRegisteredExpression(const Stmt * stmt)120 AnalysisDeclContext::getBlockForRegisteredExpression(const Stmt *stmt) {
121 assert(forcedBlkExprs);
122 if (const Expr *e = dyn_cast<Expr>(stmt))
123 stmt = e->IgnoreParens();
124 CFG::BuildOptions::ForcedBlkExprs::const_iterator itr =
125 forcedBlkExprs->find(stmt);
126 assert(itr != forcedBlkExprs->end());
127 return itr->second;
128 }
129
getCFG()130 CFG *AnalysisDeclContext::getCFG() {
131 if (!cfgBuildOptions.PruneTriviallyFalseEdges)
132 return getUnoptimizedCFG();
133
134 if (!builtCFG) {
135 cfg.reset(CFG::buildCFG(D, getBody(),
136 &D->getASTContext(), cfgBuildOptions));
137 // Even when the cfg is not successfully built, we don't
138 // want to try building it again.
139 builtCFG = true;
140 }
141 return cfg.get();
142 }
143
getUnoptimizedCFG()144 CFG *AnalysisDeclContext::getUnoptimizedCFG() {
145 if (!builtCompleteCFG) {
146 SaveAndRestore<bool> NotPrune(cfgBuildOptions.PruneTriviallyFalseEdges,
147 false);
148 completeCFG.reset(CFG::buildCFG(D, getBody(), &D->getASTContext(),
149 cfgBuildOptions));
150 // Even when the cfg is not successfully built, we don't
151 // want to try building it again.
152 builtCompleteCFG = true;
153 }
154 return completeCFG.get();
155 }
156
getCFGStmtMap()157 CFGStmtMap *AnalysisDeclContext::getCFGStmtMap() {
158 if (cfgStmtMap)
159 return cfgStmtMap.get();
160
161 if (CFG *c = getCFG()) {
162 cfgStmtMap.reset(CFGStmtMap::Build(c, &getParentMap()));
163 return cfgStmtMap.get();
164 }
165
166 return 0;
167 }
168
getCFGReachablityAnalysis()169 CFGReverseBlockReachabilityAnalysis *AnalysisDeclContext::getCFGReachablityAnalysis() {
170 if (CFA)
171 return CFA.get();
172
173 if (CFG *c = getCFG()) {
174 CFA.reset(new CFGReverseBlockReachabilityAnalysis(*c));
175 return CFA.get();
176 }
177
178 return 0;
179 }
180
dumpCFG(bool ShowColors)181 void AnalysisDeclContext::dumpCFG(bool ShowColors) {
182 getCFG()->dump(getASTContext().getLangOpts(), ShowColors);
183 }
184
getParentMap()185 ParentMap &AnalysisDeclContext::getParentMap() {
186 if (!PM) {
187 PM.reset(new ParentMap(getBody()));
188 if (const CXXConstructorDecl *C = dyn_cast<CXXConstructorDecl>(getDecl())) {
189 for (CXXConstructorDecl::init_const_iterator I = C->init_begin(),
190 E = C->init_end();
191 I != E; ++I) {
192 PM->addStmt((*I)->getInit());
193 }
194 }
195 }
196 return *PM;
197 }
198
getPseudoConstantAnalysis()199 PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
200 if (!PCA)
201 PCA.reset(new PseudoConstantAnalysis(getBody()));
202 return PCA.get();
203 }
204
getContext(const Decl * D)205 AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D) {
206 AnalysisDeclContext *&AC = Contexts[D];
207 if (!AC)
208 AC = new AnalysisDeclContext(this, D, cfgBuildOptions);
209 return AC;
210 }
211
212 const StackFrameContext *
getStackFrame(LocationContext const * Parent,const Stmt * S,const CFGBlock * Blk,unsigned Idx)213 AnalysisDeclContext::getStackFrame(LocationContext const *Parent, const Stmt *S,
214 const CFGBlock *Blk, unsigned Idx) {
215 return getLocationContextManager().getStackFrame(this, Parent, S, Blk, Idx);
216 }
217
218 const BlockInvocationContext *
getBlockInvocationContext(const LocationContext * parent,const clang::BlockDecl * BD,const void * ContextData)219 AnalysisDeclContext::getBlockInvocationContext(const LocationContext *parent,
220 const clang::BlockDecl *BD,
221 const void *ContextData) {
222 return getLocationContextManager().getBlockInvocationContext(this, parent,
223 BD, ContextData);
224 }
225
getLocationContextManager()226 LocationContextManager & AnalysisDeclContext::getLocationContextManager() {
227 assert(Manager &&
228 "Cannot create LocationContexts without an AnalysisDeclContextManager!");
229 return Manager->getLocationContextManager();
230 }
231
232 //===----------------------------------------------------------------------===//
233 // FoldingSet profiling.
234 //===----------------------------------------------------------------------===//
235
ProfileCommon(llvm::FoldingSetNodeID & ID,ContextKind ck,AnalysisDeclContext * ctx,const LocationContext * parent,const void * data)236 void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
237 ContextKind ck,
238 AnalysisDeclContext *ctx,
239 const LocationContext *parent,
240 const void *data) {
241 ID.AddInteger(ck);
242 ID.AddPointer(ctx);
243 ID.AddPointer(parent);
244 ID.AddPointer(data);
245 }
246
Profile(llvm::FoldingSetNodeID & ID)247 void StackFrameContext::Profile(llvm::FoldingSetNodeID &ID) {
248 Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block, Index);
249 }
250
Profile(llvm::FoldingSetNodeID & ID)251 void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
252 Profile(ID, getAnalysisDeclContext(), getParent(), Enter);
253 }
254
Profile(llvm::FoldingSetNodeID & ID)255 void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
256 Profile(ID, getAnalysisDeclContext(), getParent(), BD, ContextData);
257 }
258
259 //===----------------------------------------------------------------------===//
260 // LocationContext creation.
261 //===----------------------------------------------------------------------===//
262
263 template <typename LOC, typename DATA>
264 const LOC*
getLocationContext(AnalysisDeclContext * ctx,const LocationContext * parent,const DATA * d)265 LocationContextManager::getLocationContext(AnalysisDeclContext *ctx,
266 const LocationContext *parent,
267 const DATA *d) {
268 llvm::FoldingSetNodeID ID;
269 LOC::Profile(ID, ctx, parent, d);
270 void *InsertPos;
271
272 LOC *L = cast_or_null<LOC>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
273
274 if (!L) {
275 L = new LOC(ctx, parent, d);
276 Contexts.InsertNode(L, InsertPos);
277 }
278 return L;
279 }
280
281 const StackFrameContext*
getStackFrame(AnalysisDeclContext * ctx,const LocationContext * parent,const Stmt * s,const CFGBlock * blk,unsigned idx)282 LocationContextManager::getStackFrame(AnalysisDeclContext *ctx,
283 const LocationContext *parent,
284 const Stmt *s,
285 const CFGBlock *blk, unsigned idx) {
286 llvm::FoldingSetNodeID ID;
287 StackFrameContext::Profile(ID, ctx, parent, s, blk, idx);
288 void *InsertPos;
289 StackFrameContext *L =
290 cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
291 if (!L) {
292 L = new StackFrameContext(ctx, parent, s, blk, idx);
293 Contexts.InsertNode(L, InsertPos);
294 }
295 return L;
296 }
297
298 const ScopeContext *
getScope(AnalysisDeclContext * ctx,const LocationContext * parent,const Stmt * s)299 LocationContextManager::getScope(AnalysisDeclContext *ctx,
300 const LocationContext *parent,
301 const Stmt *s) {
302 return getLocationContext<ScopeContext, Stmt>(ctx, parent, s);
303 }
304
305 const BlockInvocationContext *
getBlockInvocationContext(AnalysisDeclContext * ctx,const LocationContext * parent,const BlockDecl * BD,const void * ContextData)306 LocationContextManager::getBlockInvocationContext(AnalysisDeclContext *ctx,
307 const LocationContext *parent,
308 const BlockDecl *BD,
309 const void *ContextData) {
310 llvm::FoldingSetNodeID ID;
311 BlockInvocationContext::Profile(ID, ctx, parent, BD, ContextData);
312 void *InsertPos;
313 BlockInvocationContext *L =
314 cast_or_null<BlockInvocationContext>(Contexts.FindNodeOrInsertPos(ID,
315 InsertPos));
316 if (!L) {
317 L = new BlockInvocationContext(ctx, parent, BD, ContextData);
318 Contexts.InsertNode(L, InsertPos);
319 }
320 return L;
321 }
322
323 //===----------------------------------------------------------------------===//
324 // LocationContext methods.
325 //===----------------------------------------------------------------------===//
326
getCurrentStackFrame() const327 const StackFrameContext *LocationContext::getCurrentStackFrame() const {
328 const LocationContext *LC = this;
329 while (LC) {
330 if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC))
331 return SFC;
332 LC = LC->getParent();
333 }
334 return NULL;
335 }
336
isParentOf(const LocationContext * LC) const337 bool LocationContext::isParentOf(const LocationContext *LC) const {
338 do {
339 const LocationContext *Parent = LC->getParent();
340 if (Parent == this)
341 return true;
342 else
343 LC = Parent;
344 } while (LC);
345
346 return false;
347 }
348
349 //===----------------------------------------------------------------------===//
350 // Lazily generated map to query the external variables referenced by a Block.
351 //===----------------------------------------------------------------------===//
352
353 namespace {
354 class FindBlockDeclRefExprsVals : public StmtVisitor<FindBlockDeclRefExprsVals>{
355 BumpVector<const VarDecl*> &BEVals;
356 BumpVectorContext &BC;
357 llvm::SmallPtrSet<const VarDecl*, 4> Visited;
358 llvm::SmallPtrSet<const DeclContext*, 4> IgnoredContexts;
359 public:
FindBlockDeclRefExprsVals(BumpVector<const VarDecl * > & bevals,BumpVectorContext & bc)360 FindBlockDeclRefExprsVals(BumpVector<const VarDecl*> &bevals,
361 BumpVectorContext &bc)
362 : BEVals(bevals), BC(bc) {}
363
IsTrackedDecl(const VarDecl * VD)364 bool IsTrackedDecl(const VarDecl *VD) {
365 const DeclContext *DC = VD->getDeclContext();
366 return IgnoredContexts.count(DC) == 0;
367 }
368
VisitStmt(Stmt * S)369 void VisitStmt(Stmt *S) {
370 for (Stmt::child_range I = S->children(); I; ++I)
371 if (Stmt *child = *I)
372 Visit(child);
373 }
374
VisitDeclRefExpr(DeclRefExpr * DR)375 void VisitDeclRefExpr(DeclRefExpr *DR) {
376 // Non-local variables are also directly modified.
377 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
378 if (!VD->hasLocalStorage()) {
379 if (Visited.insert(VD))
380 BEVals.push_back(VD, BC);
381 } else if (DR->refersToEnclosingLocal()) {
382 if (Visited.insert(VD) && IsTrackedDecl(VD))
383 BEVals.push_back(VD, BC);
384 }
385 }
386 }
387
VisitBlockExpr(BlockExpr * BR)388 void VisitBlockExpr(BlockExpr *BR) {
389 // Blocks containing blocks can transitively capture more variables.
390 IgnoredContexts.insert(BR->getBlockDecl());
391 Visit(BR->getBlockDecl()->getBody());
392 }
393
VisitPseudoObjectExpr(PseudoObjectExpr * PE)394 void VisitPseudoObjectExpr(PseudoObjectExpr *PE) {
395 for (PseudoObjectExpr::semantics_iterator it = PE->semantics_begin(),
396 et = PE->semantics_end(); it != et; ++it) {
397 Expr *Semantic = *it;
398 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
399 Semantic = OVE->getSourceExpr();
400 Visit(Semantic);
401 }
402 }
403 };
404 } // end anonymous namespace
405
406 typedef BumpVector<const VarDecl*> DeclVec;
407
LazyInitializeReferencedDecls(const BlockDecl * BD,void * & Vec,llvm::BumpPtrAllocator & A)408 static DeclVec* LazyInitializeReferencedDecls(const BlockDecl *BD,
409 void *&Vec,
410 llvm::BumpPtrAllocator &A) {
411 if (Vec)
412 return (DeclVec*) Vec;
413
414 BumpVectorContext BC(A);
415 DeclVec *BV = (DeclVec*) A.Allocate<DeclVec>();
416 new (BV) DeclVec(BC, 10);
417
418 // Find the referenced variables.
419 FindBlockDeclRefExprsVals F(*BV, BC);
420 F.Visit(BD->getBody());
421
422 Vec = BV;
423 return BV;
424 }
425
426 std::pair<AnalysisDeclContext::referenced_decls_iterator,
427 AnalysisDeclContext::referenced_decls_iterator>
getReferencedBlockVars(const BlockDecl * BD)428 AnalysisDeclContext::getReferencedBlockVars(const BlockDecl *BD) {
429 if (!ReferencedBlockVars)
430 ReferencedBlockVars = new llvm::DenseMap<const BlockDecl*,void*>();
431
432 DeclVec *V = LazyInitializeReferencedDecls(BD, (*ReferencedBlockVars)[BD], A);
433 return std::make_pair(V->begin(), V->end());
434 }
435
getAnalysisImpl(const void * tag)436 ManagedAnalysis *&AnalysisDeclContext::getAnalysisImpl(const void *tag) {
437 if (!ManagedAnalyses)
438 ManagedAnalyses = new ManagedAnalysisMap();
439 ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
440 return (*M)[tag];
441 }
442
443 //===----------------------------------------------------------------------===//
444 // Cleanup.
445 //===----------------------------------------------------------------------===//
446
~ManagedAnalysis()447 ManagedAnalysis::~ManagedAnalysis() {}
448
~AnalysisDeclContext()449 AnalysisDeclContext::~AnalysisDeclContext() {
450 delete forcedBlkExprs;
451 delete ReferencedBlockVars;
452 // Release the managed analyses.
453 if (ManagedAnalyses) {
454 ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
455 for (ManagedAnalysisMap::iterator I = M->begin(), E = M->end(); I!=E; ++I)
456 delete I->second;
457 delete M;
458 }
459 }
460
~AnalysisDeclContextManager()461 AnalysisDeclContextManager::~AnalysisDeclContextManager() {
462 for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
463 delete I->second;
464 }
465
~LocationContext()466 LocationContext::~LocationContext() {}
467
~LocationContextManager()468 LocationContextManager::~LocationContextManager() {
469 clear();
470 }
471
clear()472 void LocationContextManager::clear() {
473 for (llvm::FoldingSet<LocationContext>::iterator I = Contexts.begin(),
474 E = Contexts.end(); I != E; ) {
475 LocationContext *LC = &*I;
476 ++I;
477 delete LC;
478 }
479
480 Contexts.clear();
481 }
482
483