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/Decl.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/ParentMap.h"
19 #include "clang/AST/StmtVisitor.h"
20 #include "clang/Analysis/Analyses/LiveVariables.h"
21 #include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
22 #include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
23 #include "clang/Analysis/AnalysisContext.h"
24 #include "clang/Analysis/CFG.h"
25 #include "clang/Analysis/CFGStmtMap.h"
26 #include "clang/Analysis/Support/BumpVector.h"
27 #include "llvm/Support/SaveAndRestore.h"
28 #include "llvm/ADT/SmallPtrSet.h"
29 #include "llvm/Support/ErrorHandling.h"
30
31 using namespace clang;
32
33 typedef llvm::DenseMap<const void *, ManagedAnalysis *> ManagedAnalysisMap;
34
AnalysisDeclContext(AnalysisDeclContextManager * Mgr,const Decl * d,idx::TranslationUnit * tu,const CFG::BuildOptions & buildOptions)35 AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
36 const Decl *d,
37 idx::TranslationUnit *tu,
38 const CFG::BuildOptions &buildOptions)
39 : Manager(Mgr),
40 D(d),
41 TU(tu),
42 cfgBuildOptions(buildOptions),
43 forcedBlkExprs(0),
44 builtCFG(false),
45 builtCompleteCFG(false),
46 ReferencedBlockVars(0),
47 ManagedAnalyses(0)
48 {
49 cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
50 }
51
AnalysisDeclContext(AnalysisDeclContextManager * Mgr,const Decl * d,idx::TranslationUnit * tu)52 AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
53 const Decl *d,
54 idx::TranslationUnit *tu)
55 : Manager(Mgr),
56 D(d),
57 TU(tu),
58 forcedBlkExprs(0),
59 builtCFG(false),
60 builtCompleteCFG(false),
61 ReferencedBlockVars(0),
62 ManagedAnalyses(0)
63 {
64 cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
65 }
66
AnalysisDeclContextManager(bool useUnoptimizedCFG,bool addImplicitDtors,bool addInitializers)67 AnalysisDeclContextManager::AnalysisDeclContextManager(bool useUnoptimizedCFG,
68 bool addImplicitDtors,
69 bool addInitializers) {
70 cfgBuildOptions.PruneTriviallyFalseEdges = !useUnoptimizedCFG;
71 cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
72 cfgBuildOptions.AddInitializers = addInitializers;
73 }
74
clear()75 void AnalysisDeclContextManager::clear() {
76 for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
77 delete I->second;
78 Contexts.clear();
79 }
80
getBody() const81 Stmt *AnalysisDeclContext::getBody() const {
82 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
83 return FD->getBody();
84 else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
85 return MD->getBody();
86 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
87 return BD->getBody();
88 else if (const FunctionTemplateDecl *FunTmpl
89 = dyn_cast_or_null<FunctionTemplateDecl>(D))
90 return FunTmpl->getTemplatedDecl()->getBody();
91
92 llvm_unreachable("unknown code decl");
93 }
94
getSelfDecl() const95 const ImplicitParamDecl *AnalysisDeclContext::getSelfDecl() const {
96 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
97 return MD->getSelfDecl();
98 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
99 // See if 'self' was captured by the block.
100 for (BlockDecl::capture_const_iterator it = BD->capture_begin(),
101 et = BD->capture_end(); it != et; ++it) {
102 const VarDecl *VD = it->getVariable();
103 if (VD->getName() == "self")
104 return dyn_cast<ImplicitParamDecl>(VD);
105 }
106 }
107
108 return NULL;
109 }
110
registerForcedBlockExpression(const Stmt * stmt)111 void AnalysisDeclContext::registerForcedBlockExpression(const Stmt *stmt) {
112 if (!forcedBlkExprs)
113 forcedBlkExprs = new CFG::BuildOptions::ForcedBlkExprs();
114 // Default construct an entry for 'stmt'.
115 if (const Expr *e = dyn_cast<Expr>(stmt))
116 stmt = e->IgnoreParens();
117 (void) (*forcedBlkExprs)[stmt];
118 }
119
120 const CFGBlock *
getBlockForRegisteredExpression(const Stmt * stmt)121 AnalysisDeclContext::getBlockForRegisteredExpression(const Stmt *stmt) {
122 assert(forcedBlkExprs);
123 if (const Expr *e = dyn_cast<Expr>(stmt))
124 stmt = e->IgnoreParens();
125 CFG::BuildOptions::ForcedBlkExprs::const_iterator itr =
126 forcedBlkExprs->find(stmt);
127 assert(itr != forcedBlkExprs->end());
128 return itr->second;
129 }
130
getCFG()131 CFG *AnalysisDeclContext::getCFG() {
132 if (!cfgBuildOptions.PruneTriviallyFalseEdges)
133 return getUnoptimizedCFG();
134
135 if (!builtCFG) {
136 cfg.reset(CFG::buildCFG(D, getBody(),
137 &D->getASTContext(), cfgBuildOptions));
138 // Even when the cfg is not successfully built, we don't
139 // want to try building it again.
140 builtCFG = true;
141 }
142 return cfg.get();
143 }
144
getUnoptimizedCFG()145 CFG *AnalysisDeclContext::getUnoptimizedCFG() {
146 if (!builtCompleteCFG) {
147 SaveAndRestore<bool> NotPrune(cfgBuildOptions.PruneTriviallyFalseEdges,
148 false);
149 completeCFG.reset(CFG::buildCFG(D, getBody(), &D->getASTContext(),
150 cfgBuildOptions));
151 // Even when the cfg is not successfully built, we don't
152 // want to try building it again.
153 builtCompleteCFG = true;
154 }
155 return completeCFG.get();
156 }
157
getCFGStmtMap()158 CFGStmtMap *AnalysisDeclContext::getCFGStmtMap() {
159 if (cfgStmtMap)
160 return cfgStmtMap.get();
161
162 if (CFG *c = getCFG()) {
163 cfgStmtMap.reset(CFGStmtMap::Build(c, &getParentMap()));
164 return cfgStmtMap.get();
165 }
166
167 return 0;
168 }
169
getCFGReachablityAnalysis()170 CFGReverseBlockReachabilityAnalysis *AnalysisDeclContext::getCFGReachablityAnalysis() {
171 if (CFA)
172 return CFA.get();
173
174 if (CFG *c = getCFG()) {
175 CFA.reset(new CFGReverseBlockReachabilityAnalysis(*c));
176 return CFA.get();
177 }
178
179 return 0;
180 }
181
dumpCFG(bool ShowColors)182 void AnalysisDeclContext::dumpCFG(bool ShowColors) {
183 getCFG()->dump(getASTContext().getLangOpts(), ShowColors);
184 }
185
getParentMap()186 ParentMap &AnalysisDeclContext::getParentMap() {
187 if (!PM)
188 PM.reset(new ParentMap(getBody()));
189 return *PM;
190 }
191
getPseudoConstantAnalysis()192 PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
193 if (!PCA)
194 PCA.reset(new PseudoConstantAnalysis(getBody()));
195 return PCA.get();
196 }
197
getContext(const Decl * D,idx::TranslationUnit * TU)198 AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D,
199 idx::TranslationUnit *TU) {
200 AnalysisDeclContext *&AC = Contexts[D];
201 if (!AC)
202 AC = new AnalysisDeclContext(this, D, TU, cfgBuildOptions);
203 return AC;
204 }
205
206 const StackFrameContext *
getStackFrame(LocationContext const * Parent,const Stmt * S,const CFGBlock * Blk,unsigned Idx)207 AnalysisDeclContext::getStackFrame(LocationContext const *Parent, const Stmt *S,
208 const CFGBlock *Blk, unsigned Idx) {
209 return getLocationContextManager().getStackFrame(this, Parent, S, Blk, Idx);
210 }
211
getLocationContextManager()212 LocationContextManager & AnalysisDeclContext::getLocationContextManager() {
213 assert(Manager &&
214 "Cannot create LocationContexts without an AnalysisDeclContextManager!");
215 return Manager->getLocationContextManager();
216 }
217
218 //===----------------------------------------------------------------------===//
219 // FoldingSet profiling.
220 //===----------------------------------------------------------------------===//
221
ProfileCommon(llvm::FoldingSetNodeID & ID,ContextKind ck,AnalysisDeclContext * ctx,const LocationContext * parent,const void * data)222 void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
223 ContextKind ck,
224 AnalysisDeclContext *ctx,
225 const LocationContext *parent,
226 const void *data) {
227 ID.AddInteger(ck);
228 ID.AddPointer(ctx);
229 ID.AddPointer(parent);
230 ID.AddPointer(data);
231 }
232
Profile(llvm::FoldingSetNodeID & ID)233 void StackFrameContext::Profile(llvm::FoldingSetNodeID &ID) {
234 Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block, Index);
235 }
236
Profile(llvm::FoldingSetNodeID & ID)237 void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
238 Profile(ID, getAnalysisDeclContext(), getParent(), Enter);
239 }
240
Profile(llvm::FoldingSetNodeID & ID)241 void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
242 Profile(ID, getAnalysisDeclContext(), getParent(), BD);
243 }
244
245 //===----------------------------------------------------------------------===//
246 // LocationContext creation.
247 //===----------------------------------------------------------------------===//
248
249 template <typename LOC, typename DATA>
250 const LOC*
getLocationContext(AnalysisDeclContext * ctx,const LocationContext * parent,const DATA * d)251 LocationContextManager::getLocationContext(AnalysisDeclContext *ctx,
252 const LocationContext *parent,
253 const DATA *d) {
254 llvm::FoldingSetNodeID ID;
255 LOC::Profile(ID, ctx, parent, d);
256 void *InsertPos;
257
258 LOC *L = cast_or_null<LOC>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
259
260 if (!L) {
261 L = new LOC(ctx, parent, d);
262 Contexts.InsertNode(L, InsertPos);
263 }
264 return L;
265 }
266
267 const StackFrameContext*
getStackFrame(AnalysisDeclContext * ctx,const LocationContext * parent,const Stmt * s,const CFGBlock * blk,unsigned idx)268 LocationContextManager::getStackFrame(AnalysisDeclContext *ctx,
269 const LocationContext *parent,
270 const Stmt *s,
271 const CFGBlock *blk, unsigned idx) {
272 llvm::FoldingSetNodeID ID;
273 StackFrameContext::Profile(ID, ctx, parent, s, blk, idx);
274 void *InsertPos;
275 StackFrameContext *L =
276 cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
277 if (!L) {
278 L = new StackFrameContext(ctx, parent, s, blk, idx);
279 Contexts.InsertNode(L, InsertPos);
280 }
281 return L;
282 }
283
284 const ScopeContext *
getScope(AnalysisDeclContext * ctx,const LocationContext * parent,const Stmt * s)285 LocationContextManager::getScope(AnalysisDeclContext *ctx,
286 const LocationContext *parent,
287 const Stmt *s) {
288 return getLocationContext<ScopeContext, Stmt>(ctx, parent, s);
289 }
290
291 //===----------------------------------------------------------------------===//
292 // LocationContext methods.
293 //===----------------------------------------------------------------------===//
294
getCurrentStackFrame() const295 const StackFrameContext *LocationContext::getCurrentStackFrame() const {
296 const LocationContext *LC = this;
297 while (LC) {
298 if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC))
299 return SFC;
300 LC = LC->getParent();
301 }
302 return NULL;
303 }
304
305 const StackFrameContext *
getStackFrameForDeclContext(const DeclContext * DC) const306 LocationContext::getStackFrameForDeclContext(const DeclContext *DC) const {
307 const LocationContext *LC = this;
308 while (LC) {
309 if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
310 if (cast<DeclContext>(SFC->getDecl()) == DC)
311 return SFC;
312 }
313 LC = LC->getParent();
314 }
315 return NULL;
316 }
317
isParentOf(const LocationContext * LC) const318 bool LocationContext::isParentOf(const LocationContext *LC) const {
319 do {
320 const LocationContext *Parent = LC->getParent();
321 if (Parent == this)
322 return true;
323 else
324 LC = Parent;
325 } while (LC);
326
327 return false;
328 }
329
330 //===----------------------------------------------------------------------===//
331 // Lazily generated map to query the external variables referenced by a Block.
332 //===----------------------------------------------------------------------===//
333
334 namespace {
335 class FindBlockDeclRefExprsVals : public StmtVisitor<FindBlockDeclRefExprsVals>{
336 BumpVector<const VarDecl*> &BEVals;
337 BumpVectorContext &BC;
338 llvm::SmallPtrSet<const VarDecl*, 4> Visited;
339 llvm::SmallPtrSet<const DeclContext*, 4> IgnoredContexts;
340 public:
FindBlockDeclRefExprsVals(BumpVector<const VarDecl * > & bevals,BumpVectorContext & bc)341 FindBlockDeclRefExprsVals(BumpVector<const VarDecl*> &bevals,
342 BumpVectorContext &bc)
343 : BEVals(bevals), BC(bc) {}
344
IsTrackedDecl(const VarDecl * VD)345 bool IsTrackedDecl(const VarDecl *VD) {
346 const DeclContext *DC = VD->getDeclContext();
347 return IgnoredContexts.count(DC) == 0;
348 }
349
VisitStmt(Stmt * S)350 void VisitStmt(Stmt *S) {
351 for (Stmt::child_range I = S->children(); I; ++I)
352 if (Stmt *child = *I)
353 Visit(child);
354 }
355
VisitDeclRefExpr(DeclRefExpr * DR)356 void VisitDeclRefExpr(DeclRefExpr *DR) {
357 // Non-local variables are also directly modified.
358 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
359 if (!VD->hasLocalStorage()) {
360 if (Visited.insert(VD))
361 BEVals.push_back(VD, BC);
362 } else if (DR->refersToEnclosingLocal()) {
363 if (Visited.insert(VD) && IsTrackedDecl(VD))
364 BEVals.push_back(VD, BC);
365 }
366 }
367 }
368
VisitBlockExpr(BlockExpr * BR)369 void VisitBlockExpr(BlockExpr *BR) {
370 // Blocks containing blocks can transitively capture more variables.
371 IgnoredContexts.insert(BR->getBlockDecl());
372 Visit(BR->getBlockDecl()->getBody());
373 }
374
VisitPseudoObjectExpr(PseudoObjectExpr * PE)375 void VisitPseudoObjectExpr(PseudoObjectExpr *PE) {
376 for (PseudoObjectExpr::semantics_iterator it = PE->semantics_begin(),
377 et = PE->semantics_end(); it != et; ++it) {
378 Expr *Semantic = *it;
379 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
380 Semantic = OVE->getSourceExpr();
381 Visit(Semantic);
382 }
383 }
384 };
385 } // end anonymous namespace
386
387 typedef BumpVector<const VarDecl*> DeclVec;
388
LazyInitializeReferencedDecls(const BlockDecl * BD,void * & Vec,llvm::BumpPtrAllocator & A)389 static DeclVec* LazyInitializeReferencedDecls(const BlockDecl *BD,
390 void *&Vec,
391 llvm::BumpPtrAllocator &A) {
392 if (Vec)
393 return (DeclVec*) Vec;
394
395 BumpVectorContext BC(A);
396 DeclVec *BV = (DeclVec*) A.Allocate<DeclVec>();
397 new (BV) DeclVec(BC, 10);
398
399 // Find the referenced variables.
400 FindBlockDeclRefExprsVals F(*BV, BC);
401 F.Visit(BD->getBody());
402
403 Vec = BV;
404 return BV;
405 }
406
407 std::pair<AnalysisDeclContext::referenced_decls_iterator,
408 AnalysisDeclContext::referenced_decls_iterator>
getReferencedBlockVars(const BlockDecl * BD)409 AnalysisDeclContext::getReferencedBlockVars(const BlockDecl *BD) {
410 if (!ReferencedBlockVars)
411 ReferencedBlockVars = new llvm::DenseMap<const BlockDecl*,void*>();
412
413 DeclVec *V = LazyInitializeReferencedDecls(BD, (*ReferencedBlockVars)[BD], A);
414 return std::make_pair(V->begin(), V->end());
415 }
416
getAnalysisImpl(const void * tag)417 ManagedAnalysis *&AnalysisDeclContext::getAnalysisImpl(const void *tag) {
418 if (!ManagedAnalyses)
419 ManagedAnalyses = new ManagedAnalysisMap();
420 ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
421 return (*M)[tag];
422 }
423
424 //===----------------------------------------------------------------------===//
425 // Cleanup.
426 //===----------------------------------------------------------------------===//
427
~ManagedAnalysis()428 ManagedAnalysis::~ManagedAnalysis() {}
429
~AnalysisDeclContext()430 AnalysisDeclContext::~AnalysisDeclContext() {
431 delete forcedBlkExprs;
432 delete ReferencedBlockVars;
433 // Release the managed analyses.
434 if (ManagedAnalyses) {
435 ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
436 for (ManagedAnalysisMap::iterator I = M->begin(), E = M->end(); I!=E; ++I)
437 delete I->second;
438 delete M;
439 }
440 }
441
~AnalysisDeclContextManager()442 AnalysisDeclContextManager::~AnalysisDeclContextManager() {
443 for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
444 delete I->second;
445 }
446
~LocationContext()447 LocationContext::~LocationContext() {}
448
~LocationContextManager()449 LocationContextManager::~LocationContextManager() {
450 clear();
451 }
452
clear()453 void LocationContextManager::clear() {
454 for (llvm::FoldingSet<LocationContext>::iterator I = Contexts.begin(),
455 E = Contexts.end(); I != E; ) {
456 LocationContext *LC = &*I;
457 ++I;
458 delete LC;
459 }
460
461 Contexts.clear();
462 }
463
464