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/Analysis/AnalysisDeclContext.h"
16 #include "BodyFarm.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/DeclTemplate.h"
21 #include "clang/AST/ParentMap.h"
22 #include "clang/AST/StmtVisitor.h"
23 #include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
24 #include "clang/Analysis/Analyses/LiveVariables.h"
25 #include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
26 #include "clang/Analysis/CFG.h"
27 #include "clang/Analysis/CFGStmtMap.h"
28 #include "clang/Analysis/Support/BumpVector.h"
29 #include "llvm/ADT/SmallPtrSet.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/SaveAndRestore.h"
32 #include "llvm/Support/raw_ostream.h"
33 
34 using namespace clang;
35 
36 typedef llvm::DenseMap<const void *, ManagedAnalysis *> ManagedAnalysisMap;
37 
38 AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
39                                          const Decl *d,
40                                          const CFG::BuildOptions &buildOptions)
41   : Manager(Mgr),
42     D(d),
43     cfgBuildOptions(buildOptions),
44     forcedBlkExprs(nullptr),
45     builtCFG(false),
46     builtCompleteCFG(false),
47     ReferencedBlockVars(nullptr),
48     ManagedAnalyses(nullptr)
49 {
50   cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
51 }
52 
53 AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
54                                          const Decl *d)
55 : Manager(Mgr),
56   D(d),
57   forcedBlkExprs(nullptr),
58   builtCFG(false),
59   builtCompleteCFG(false),
60   ReferencedBlockVars(nullptr),
61   ManagedAnalyses(nullptr)
62 {
63   cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
64 }
65 
66 AnalysisDeclContextManager::AnalysisDeclContextManager(bool useUnoptimizedCFG,
67                                                        bool addImplicitDtors,
68                                                        bool addInitializers,
69                                                        bool addTemporaryDtors,
70                                                        bool addLifetime,
71                                                        bool addLoopExit,
72                                                        bool synthesizeBodies,
73                                                        bool addStaticInitBranch,
74                                                        bool addCXXNewAllocator,
75                                                        CodeInjector *injector)
76   : Injector(injector), SynthesizeBodies(synthesizeBodies)
77 {
78   cfgBuildOptions.PruneTriviallyFalseEdges = !useUnoptimizedCFG;
79   cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
80   cfgBuildOptions.AddInitializers = addInitializers;
81   cfgBuildOptions.AddTemporaryDtors = addTemporaryDtors;
82   cfgBuildOptions.AddLifetime = addLifetime;
83   cfgBuildOptions.AddLoopExit = addLoopExit;
84   cfgBuildOptions.AddStaticInitBranches = addStaticInitBranch;
85   cfgBuildOptions.AddCXXNewAllocator = addCXXNewAllocator;
86 }
87 
88 void AnalysisDeclContextManager::clear() { Contexts.clear(); }
89 
90 static BodyFarm &getBodyFarm(ASTContext &C, CodeInjector *injector = nullptr) {
91   static BodyFarm *BF = new BodyFarm(C, injector);
92   return *BF;
93 }
94 
95 Stmt *AnalysisDeclContext::getBody(bool &IsAutosynthesized) const {
96   IsAutosynthesized = false;
97   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
98     Stmt *Body = FD->getBody();
99     if (auto *CoroBody = dyn_cast_or_null<CoroutineBodyStmt>(Body))
100       Body = CoroBody->getBody();
101     if (Manager && Manager->synthesizeBodies()) {
102       Stmt *SynthesizedBody =
103           getBodyFarm(getASTContext(), Manager->Injector.get()).getBody(FD);
104       if (SynthesizedBody) {
105         Body = SynthesizedBody;
106         IsAutosynthesized = true;
107       }
108     }
109     return Body;
110   }
111   else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
112     Stmt *Body = MD->getBody();
113     if (Manager && Manager->synthesizeBodies()) {
114       Stmt *SynthesizedBody =
115           getBodyFarm(getASTContext(), Manager->Injector.get()).getBody(MD);
116       if (SynthesizedBody) {
117         Body = SynthesizedBody;
118         IsAutosynthesized = true;
119       }
120     }
121     return Body;
122   } else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
123     return BD->getBody();
124   else if (const FunctionTemplateDecl *FunTmpl
125            = dyn_cast_or_null<FunctionTemplateDecl>(D))
126     return FunTmpl->getTemplatedDecl()->getBody();
127 
128   llvm_unreachable("unknown code decl");
129 }
130 
131 Stmt *AnalysisDeclContext::getBody() const {
132   bool Tmp;
133   return getBody(Tmp);
134 }
135 
136 bool AnalysisDeclContext::isBodyAutosynthesized() const {
137   bool Tmp;
138   getBody(Tmp);
139   return Tmp;
140 }
141 
142 bool AnalysisDeclContext::isBodyAutosynthesizedFromModelFile() const {
143   bool Tmp;
144   Stmt *Body = getBody(Tmp);
145   return Tmp && Body->getLocStart().isValid();
146 }
147 
148 /// Returns true if \param VD is an Objective-C implicit 'self' parameter.
149 static bool isSelfDecl(const VarDecl *VD) {
150   return isa<ImplicitParamDecl>(VD) && VD->getName() == "self";
151 }
152 
153 const ImplicitParamDecl *AnalysisDeclContext::getSelfDecl() const {
154   if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
155     return MD->getSelfDecl();
156   if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
157     // See if 'self' was captured by the block.
158     for (const auto &I : BD->captures()) {
159       const VarDecl *VD = I.getVariable();
160       if (isSelfDecl(VD))
161         return dyn_cast<ImplicitParamDecl>(VD);
162     }
163   }
164 
165   auto *CXXMethod = dyn_cast<CXXMethodDecl>(D);
166   if (!CXXMethod)
167     return nullptr;
168 
169   const CXXRecordDecl *parent = CXXMethod->getParent();
170   if (!parent->isLambda())
171     return nullptr;
172 
173   for (const LambdaCapture &LC : parent->captures()) {
174     if (!LC.capturesVariable())
175       continue;
176 
177     VarDecl *VD = LC.getCapturedVar();
178     if (isSelfDecl(VD))
179       return dyn_cast<ImplicitParamDecl>(VD);
180   }
181 
182   return nullptr;
183 }
184 
185 void AnalysisDeclContext::registerForcedBlockExpression(const Stmt *stmt) {
186   if (!forcedBlkExprs)
187     forcedBlkExprs = new CFG::BuildOptions::ForcedBlkExprs();
188   // Default construct an entry for 'stmt'.
189   if (const Expr *e = dyn_cast<Expr>(stmt))
190     stmt = e->IgnoreParens();
191   (void) (*forcedBlkExprs)[stmt];
192 }
193 
194 const CFGBlock *
195 AnalysisDeclContext::getBlockForRegisteredExpression(const Stmt *stmt) {
196   assert(forcedBlkExprs);
197   if (const Expr *e = dyn_cast<Expr>(stmt))
198     stmt = e->IgnoreParens();
199   CFG::BuildOptions::ForcedBlkExprs::const_iterator itr =
200     forcedBlkExprs->find(stmt);
201   assert(itr != forcedBlkExprs->end());
202   return itr->second;
203 }
204 
205 /// Add each synthetic statement in the CFG to the parent map, using the
206 /// source statement's parent.
207 static void addParentsForSyntheticStmts(const CFG *TheCFG, ParentMap &PM) {
208   if (!TheCFG)
209     return;
210 
211   for (CFG::synthetic_stmt_iterator I = TheCFG->synthetic_stmt_begin(),
212                                     E = TheCFG->synthetic_stmt_end();
213        I != E; ++I) {
214     PM.setParent(I->first, PM.getParent(I->second));
215   }
216 }
217 
218 CFG *AnalysisDeclContext::getCFG() {
219   if (!cfgBuildOptions.PruneTriviallyFalseEdges)
220     return getUnoptimizedCFG();
221 
222   if (!builtCFG) {
223     cfg = CFG::buildCFG(D, getBody(), &D->getASTContext(), cfgBuildOptions);
224     // Even when the cfg is not successfully built, we don't
225     // want to try building it again.
226     builtCFG = true;
227 
228     if (PM)
229       addParentsForSyntheticStmts(cfg.get(), *PM);
230 
231     // The Observer should only observe one build of the CFG.
232     getCFGBuildOptions().Observer = nullptr;
233   }
234   return cfg.get();
235 }
236 
237 CFG *AnalysisDeclContext::getUnoptimizedCFG() {
238   if (!builtCompleteCFG) {
239     SaveAndRestore<bool> NotPrune(cfgBuildOptions.PruneTriviallyFalseEdges,
240                                   false);
241     completeCFG =
242         CFG::buildCFG(D, getBody(), &D->getASTContext(), cfgBuildOptions);
243     // Even when the cfg is not successfully built, we don't
244     // want to try building it again.
245     builtCompleteCFG = true;
246 
247     if (PM)
248       addParentsForSyntheticStmts(completeCFG.get(), *PM);
249 
250     // The Observer should only observe one build of the CFG.
251     getCFGBuildOptions().Observer = nullptr;
252   }
253   return completeCFG.get();
254 }
255 
256 CFGStmtMap *AnalysisDeclContext::getCFGStmtMap() {
257   if (cfgStmtMap)
258     return cfgStmtMap.get();
259 
260   if (CFG *c = getCFG()) {
261     cfgStmtMap.reset(CFGStmtMap::Build(c, &getParentMap()));
262     return cfgStmtMap.get();
263   }
264 
265   return nullptr;
266 }
267 
268 CFGReverseBlockReachabilityAnalysis *AnalysisDeclContext::getCFGReachablityAnalysis() {
269   if (CFA)
270     return CFA.get();
271 
272   if (CFG *c = getCFG()) {
273     CFA.reset(new CFGReverseBlockReachabilityAnalysis(*c));
274     return CFA.get();
275   }
276 
277   return nullptr;
278 }
279 
280 void AnalysisDeclContext::dumpCFG(bool ShowColors) {
281     getCFG()->dump(getASTContext().getLangOpts(), ShowColors);
282 }
283 
284 ParentMap &AnalysisDeclContext::getParentMap() {
285   if (!PM) {
286     PM.reset(new ParentMap(getBody()));
287     if (const CXXConstructorDecl *C = dyn_cast<CXXConstructorDecl>(getDecl())) {
288       for (const auto *I : C->inits()) {
289         PM->addStmt(I->getInit());
290       }
291     }
292     if (builtCFG)
293       addParentsForSyntheticStmts(getCFG(), *PM);
294     if (builtCompleteCFG)
295       addParentsForSyntheticStmts(getUnoptimizedCFG(), *PM);
296   }
297   return *PM;
298 }
299 
300 PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
301   if (!PCA)
302     PCA.reset(new PseudoConstantAnalysis(getBody()));
303   return PCA.get();
304 }
305 
306 AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D) {
307   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
308     // Calling 'hasBody' replaces 'FD' in place with the FunctionDecl
309     // that has the body.
310     FD->hasBody(FD);
311     D = FD;
312   }
313 
314   std::unique_ptr<AnalysisDeclContext> &AC = Contexts[D];
315   if (!AC)
316     AC = llvm::make_unique<AnalysisDeclContext>(this, D, cfgBuildOptions);
317   return AC.get();
318 }
319 
320 const StackFrameContext *
321 AnalysisDeclContext::getStackFrame(LocationContext const *Parent, const Stmt *S,
322                                const CFGBlock *Blk, unsigned Idx) {
323   return getLocationContextManager().getStackFrame(this, Parent, S, Blk, Idx);
324 }
325 
326 const BlockInvocationContext *
327 AnalysisDeclContext::getBlockInvocationContext(const LocationContext *parent,
328                                                const clang::BlockDecl *BD,
329                                                const void *ContextData) {
330   return getLocationContextManager().getBlockInvocationContext(this, parent,
331                                                                BD, ContextData);
332 }
333 
334 bool AnalysisDeclContext::isInStdNamespace(const Decl *D) {
335   const DeclContext *DC = D->getDeclContext()->getEnclosingNamespaceContext();
336   const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC);
337   if (!ND)
338     return false;
339 
340   while (const DeclContext *Parent = ND->getParent()) {
341     if (!isa<NamespaceDecl>(Parent))
342       break;
343     ND = cast<NamespaceDecl>(Parent);
344   }
345 
346   return ND->isStdNamespace();
347 }
348 
349 LocationContextManager & AnalysisDeclContext::getLocationContextManager() {
350   assert(Manager &&
351          "Cannot create LocationContexts without an AnalysisDeclContextManager!");
352   return Manager->getLocationContextManager();
353 }
354 
355 //===----------------------------------------------------------------------===//
356 // FoldingSet profiling.
357 //===----------------------------------------------------------------------===//
358 
359 void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
360                                     ContextKind ck,
361                                     AnalysisDeclContext *ctx,
362                                     const LocationContext *parent,
363                                     const void *data) {
364   ID.AddInteger(ck);
365   ID.AddPointer(ctx);
366   ID.AddPointer(parent);
367   ID.AddPointer(data);
368 }
369 
370 void StackFrameContext::Profile(llvm::FoldingSetNodeID &ID) {
371   Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block, Index);
372 }
373 
374 void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
375   Profile(ID, getAnalysisDeclContext(), getParent(), Enter);
376 }
377 
378 void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
379   Profile(ID, getAnalysisDeclContext(), getParent(), BD, ContextData);
380 }
381 
382 //===----------------------------------------------------------------------===//
383 // LocationContext creation.
384 //===----------------------------------------------------------------------===//
385 
386 template <typename LOC, typename DATA>
387 const LOC*
388 LocationContextManager::getLocationContext(AnalysisDeclContext *ctx,
389                                            const LocationContext *parent,
390                                            const DATA *d) {
391   llvm::FoldingSetNodeID ID;
392   LOC::Profile(ID, ctx, parent, d);
393   void *InsertPos;
394 
395   LOC *L = cast_or_null<LOC>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
396 
397   if (!L) {
398     L = new LOC(ctx, parent, d);
399     Contexts.InsertNode(L, InsertPos);
400   }
401   return L;
402 }
403 
404 const StackFrameContext*
405 LocationContextManager::getStackFrame(AnalysisDeclContext *ctx,
406                                       const LocationContext *parent,
407                                       const Stmt *s,
408                                       const CFGBlock *blk, unsigned idx) {
409   llvm::FoldingSetNodeID ID;
410   StackFrameContext::Profile(ID, ctx, parent, s, blk, idx);
411   void *InsertPos;
412   StackFrameContext *L =
413    cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
414   if (!L) {
415     L = new StackFrameContext(ctx, parent, s, blk, idx);
416     Contexts.InsertNode(L, InsertPos);
417   }
418   return L;
419 }
420 
421 const ScopeContext *
422 LocationContextManager::getScope(AnalysisDeclContext *ctx,
423                                  const LocationContext *parent,
424                                  const Stmt *s) {
425   return getLocationContext<ScopeContext, Stmt>(ctx, parent, s);
426 }
427 
428 const BlockInvocationContext *
429 LocationContextManager::getBlockInvocationContext(AnalysisDeclContext *ctx,
430                                                   const LocationContext *parent,
431                                                   const BlockDecl *BD,
432                                                   const void *ContextData) {
433   llvm::FoldingSetNodeID ID;
434   BlockInvocationContext::Profile(ID, ctx, parent, BD, ContextData);
435   void *InsertPos;
436   BlockInvocationContext *L =
437     cast_or_null<BlockInvocationContext>(Contexts.FindNodeOrInsertPos(ID,
438                                                                     InsertPos));
439   if (!L) {
440     L = new BlockInvocationContext(ctx, parent, BD, ContextData);
441     Contexts.InsertNode(L, InsertPos);
442   }
443   return L;
444 }
445 
446 //===----------------------------------------------------------------------===//
447 // LocationContext methods.
448 //===----------------------------------------------------------------------===//
449 
450 const StackFrameContext *LocationContext::getCurrentStackFrame() const {
451   const LocationContext *LC = this;
452   while (LC) {
453     if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC))
454       return SFC;
455     LC = LC->getParent();
456   }
457   return nullptr;
458 }
459 
460 bool LocationContext::inTopFrame() const {
461   return getCurrentStackFrame()->inTopFrame();
462 }
463 
464 bool LocationContext::isParentOf(const LocationContext *LC) const {
465   do {
466     const LocationContext *Parent = LC->getParent();
467     if (Parent == this)
468       return true;
469     else
470       LC = Parent;
471   } while (LC);
472 
473   return false;
474 }
475 
476 void LocationContext::dumpStack(raw_ostream &OS, StringRef Indent) const {
477   ASTContext &Ctx = getAnalysisDeclContext()->getASTContext();
478   PrintingPolicy PP(Ctx.getLangOpts());
479   PP.TerseOutput = 1;
480 
481   unsigned Frame = 0;
482   for (const LocationContext *LCtx = this; LCtx; LCtx = LCtx->getParent()) {
483     switch (LCtx->getKind()) {
484     case StackFrame:
485       OS << Indent << '#' << Frame++ << ' ';
486       cast<StackFrameContext>(LCtx)->getDecl()->print(OS, PP);
487       OS << '\n';
488       break;
489     case Scope:
490       OS << Indent << "    (scope)\n";
491       break;
492     case Block:
493       OS << Indent << "    (block context: "
494                    << cast<BlockInvocationContext>(LCtx)->getContextData()
495                    << ")\n";
496       break;
497     }
498   }
499 }
500 
501 LLVM_DUMP_METHOD void LocationContext::dumpStack() const {
502   dumpStack(llvm::errs());
503 }
504 
505 //===----------------------------------------------------------------------===//
506 // Lazily generated map to query the external variables referenced by a Block.
507 //===----------------------------------------------------------------------===//
508 
509 namespace {
510 class FindBlockDeclRefExprsVals : public StmtVisitor<FindBlockDeclRefExprsVals>{
511   BumpVector<const VarDecl*> &BEVals;
512   BumpVectorContext &BC;
513   llvm::SmallPtrSet<const VarDecl*, 4> Visited;
514   llvm::SmallPtrSet<const DeclContext*, 4> IgnoredContexts;
515 public:
516   FindBlockDeclRefExprsVals(BumpVector<const VarDecl*> &bevals,
517                             BumpVectorContext &bc)
518   : BEVals(bevals), BC(bc) {}
519 
520   void VisitStmt(Stmt *S) {
521     for (Stmt *Child : S->children())
522       if (Child)
523         Visit(Child);
524   }
525 
526   void VisitDeclRefExpr(DeclRefExpr *DR) {
527     // Non-local variables are also directly modified.
528     if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
529       if (!VD->hasLocalStorage()) {
530         if (Visited.insert(VD).second)
531           BEVals.push_back(VD, BC);
532       }
533     }
534   }
535 
536   void VisitBlockExpr(BlockExpr *BR) {
537     // Blocks containing blocks can transitively capture more variables.
538     IgnoredContexts.insert(BR->getBlockDecl());
539     Visit(BR->getBlockDecl()->getBody());
540   }
541 
542   void VisitPseudoObjectExpr(PseudoObjectExpr *PE) {
543     for (PseudoObjectExpr::semantics_iterator it = PE->semantics_begin(),
544          et = PE->semantics_end(); it != et; ++it) {
545       Expr *Semantic = *it;
546       if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
547         Semantic = OVE->getSourceExpr();
548       Visit(Semantic);
549     }
550   }
551 };
552 } // end anonymous namespace
553 
554 typedef BumpVector<const VarDecl*> DeclVec;
555 
556 static DeclVec* LazyInitializeReferencedDecls(const BlockDecl *BD,
557                                               void *&Vec,
558                                               llvm::BumpPtrAllocator &A) {
559   if (Vec)
560     return (DeclVec*) Vec;
561 
562   BumpVectorContext BC(A);
563   DeclVec *BV = (DeclVec*) A.Allocate<DeclVec>();
564   new (BV) DeclVec(BC, 10);
565 
566   // Go through the capture list.
567   for (const auto &CI : BD->captures()) {
568     BV->push_back(CI.getVariable(), BC);
569   }
570 
571   // Find the referenced global/static variables.
572   FindBlockDeclRefExprsVals F(*BV, BC);
573   F.Visit(BD->getBody());
574 
575   Vec = BV;
576   return BV;
577 }
578 
579 llvm::iterator_range<AnalysisDeclContext::referenced_decls_iterator>
580 AnalysisDeclContext::getReferencedBlockVars(const BlockDecl *BD) {
581   if (!ReferencedBlockVars)
582     ReferencedBlockVars = new llvm::DenseMap<const BlockDecl*,void*>();
583 
584   const DeclVec *V =
585       LazyInitializeReferencedDecls(BD, (*ReferencedBlockVars)[BD], A);
586   return llvm::make_range(V->begin(), V->end());
587 }
588 
589 ManagedAnalysis *&AnalysisDeclContext::getAnalysisImpl(const void *tag) {
590   if (!ManagedAnalyses)
591     ManagedAnalyses = new ManagedAnalysisMap();
592   ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
593   return (*M)[tag];
594 }
595 
596 //===----------------------------------------------------------------------===//
597 // Cleanup.
598 //===----------------------------------------------------------------------===//
599 
600 ManagedAnalysis::~ManagedAnalysis() {}
601 
602 AnalysisDeclContext::~AnalysisDeclContext() {
603   delete forcedBlkExprs;
604   delete ReferencedBlockVars;
605   // Release the managed analyses.
606   if (ManagedAnalyses) {
607     ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
608     llvm::DeleteContainerSeconds(*M);
609     delete M;
610   }
611 }
612 
613 AnalysisDeclContextManager::~AnalysisDeclContextManager() {}
614 
615 LocationContext::~LocationContext() {}
616 
617 LocationContextManager::~LocationContextManager() {
618   clear();
619 }
620 
621 void LocationContextManager::clear() {
622   for (llvm::FoldingSet<LocationContext>::iterator I = Contexts.begin(),
623        E = Contexts.end(); I != E; ) {
624     LocationContext *LC = &*I;
625     ++I;
626     delete LC;
627   }
628 
629   Contexts.clear();
630 }
631 
632