ExprEngineCallAndReturn.cpp revision 453cb859a3c8dcafe79ae840dfc35ff8eae1b4b3
11184aebb761cbeac9124c37189a80a1a58f04b6bhkuang//=-- ExprEngineCallAndReturn.cpp - Support for call/return -----*- C++ -*-===// 21184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// 31184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// The LLVM Compiler Infrastructure 41184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// 51184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// This file is distributed under the University of Illinois Open Source 61184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// License. See LICENSE.TXT for details. 71184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// 81184aebb761cbeac9124c37189a80a1a58f04b6bhkuang//===----------------------------------------------------------------------===// 91184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// 101184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// This file defines ExprEngine's support for calls and returns. 111184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// 121184aebb761cbeac9124c37189a80a1a58f04b6bhkuang//===----------------------------------------------------------------------===// 131184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 141184aebb761cbeac9124c37189a80a1a58f04b6bhkuang#define DEBUG_TYPE "ExprEngine" 151184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 165ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 171184aebb761cbeac9124c37189a80a1a58f04b6bhkuang#include "clang/AST/CXXInheritance.h" 185ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang#include "clang/AST/DeclCXX.h" 191184aebb761cbeac9124c37189a80a1a58f04b6bhkuang#include "clang/AST/ParentMap.h" 205ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang#include "clang/Analysis/Analyses/LiveVariables.h" 21b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian#include "clang/StaticAnalyzer/Core/CheckerManager.h" 225ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 23b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian#include "llvm/ADT/SmallSet.h" 24b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian#include "llvm/ADT/Statistic.h" 25b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian#include "llvm/Support/SaveAndRestore.h" 265ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 271184aebb761cbeac9124c37189a80a1a58f04b6bhkuangusing namespace clang; 285ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangusing namespace ento; 29b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 305ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangSTATISTIC(NumOfDynamicDispatchPathSplits, 315ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang "The # of times we split the path due to imprecise dynamic dispatch info"); 325ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 335ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangSTATISTIC(NumInlinedCalls, 345ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang "The # of times we inlined a call"); 355ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 365ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangSTATISTIC(NumReachedInlineCountMax, 375ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang "The # of times we reached inline count maximum"); 385ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 395ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangvoid ExprEngine::processCallEnter(CallEnter CE, ExplodedNode *Pred) { 405ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Get the entry block in the CFG of the callee. 415ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const StackFrameContext *calleeCtx = CE.getCalleeContext(); 425ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const CFG *CalleeCFG = calleeCtx->getCFG(); 435ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const CFGBlock *Entry = &(CalleeCFG->getEntry()); 445ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 455ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Validate the CFG. 465ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang assert(Entry->empty()); 475ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang assert(Entry->succ_size() == 1); 485ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 495ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Get the solitary sucessor. 505ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const CFGBlock *Succ = *(Entry->succ_begin()); 515ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 525ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Construct an edge representing the starting location in the callee. 535ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang BlockEdge Loc(Entry, Succ, calleeCtx); 545ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 555ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ProgramStateRef state = Pred->getState(); 565ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 575ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Construct a new node and add it to the worklist. 58b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian bool isNew; 59b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian ExplodedNode *Node = G.getNode(Loc, state, false, &isNew); 60b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian Node->addPredecessor(Pred, G); 61b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (isNew) 62b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian Engine.getWorkList()->enqueue(Node); 63b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian} 64b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 65b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian// Find the last statement on the path to the exploded node and the 66b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian// corresponding Block. 67b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanianstatic std::pair<const Stmt*, 68b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const CFGBlock*> getLastStmt(const ExplodedNode *Node) { 69b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const Stmt *S = 0; 706ac915abcdb404a00d927fe6308a47fcf09d9519hkuang const CFGBlock *Blk = 0; 716ac915abcdb404a00d927fe6308a47fcf09d9519hkuang const StackFrameContext *SF = 726ac915abcdb404a00d927fe6308a47fcf09d9519hkuang Node->getLocation().getLocationContext()->getCurrentStackFrame(); 736ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 746ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // Back up through the ExplodedGraph until we reach a statement node in this 756ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // stack frame. 766ac915abcdb404a00d927fe6308a47fcf09d9519hkuang while (Node) { 776ac915abcdb404a00d927fe6308a47fcf09d9519hkuang const ProgramPoint &PP = Node->getLocation(); 785ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 795ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (PP.getLocationContext()->getCurrentStackFrame() == SF) { 805ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (const StmtPoint *SP = dyn_cast<StmtPoint>(&PP)) { 815ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang S = SP->getStmt(); 82b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian break; 836ac915abcdb404a00d927fe6308a47fcf09d9519hkuang } else if (const CallExitEnd *CEE = dyn_cast<CallExitEnd>(&PP)) { 846ac915abcdb404a00d927fe6308a47fcf09d9519hkuang S = CEE->getCalleeContext()->getCallSite(); 856ac915abcdb404a00d927fe6308a47fcf09d9519hkuang if (S) 865ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang break; 875ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 885ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // If there is no statement, this is an implicitly-generated call. 895ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // We'll walk backwards over it and then continue the loop to find 905ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // an actual statement. 915ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const CallEnter *CE; 925ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang do { 935ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang Node = Node->getFirstPred(); 945ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang CE = Node->getLocationAs<CallEnter>(); 955ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } while (!CE || CE->getCalleeContext() != CEE->getCalleeContext()); 965ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 975ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Continue searching the graph. 985ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&PP)) { 995ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang Blk = BE->getSrc(); 1005ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 101b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } else if (const CallEnter *CE = dyn_cast<CallEnter>(&PP)) { 102b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // If we reached the CallEnter for this function, it has no statements. 1035ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (CE->getCalleeContext() == SF) 1045ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang break; 105b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } 106b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 107b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (Node->pred_empty()) 108b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return std::pair<const Stmt*, const CFGBlock*>((Stmt*)0, (CFGBlock*)0); 1095ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1105ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang Node = *Node->pred_begin(); 111b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } 1121184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 113b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return std::pair<const Stmt*, const CFGBlock*>(S, Blk); 1145ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang} 1155ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1165ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang/// Adjusts a return value when the called function's return type does not 1175ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang/// match the caller's expression type. This can happen when a dynamic call 1181184aebb761cbeac9124c37189a80a1a58f04b6bhkuang/// is devirtualized, and the overridding method has a covariant (more specific) 1191184aebb761cbeac9124c37189a80a1a58f04b6bhkuang/// return type than the parent's method. For C++ objects, this means we need 1201184aebb761cbeac9124c37189a80a1a58f04b6bhkuang/// to add base casts. 1215ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangstatic SVal adjustReturnValue(SVal V, QualType ExpectedTy, QualType ActualTy, 1225ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang StoreManager &StoreMgr) { 1235ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // For now, the only adjustments we handle apply only to locations. 124b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (!isa<Loc>(V)) 125b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return V; 126b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 127b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // If the types already match, don't do any unnecessary work. 1281184aebb761cbeac9124c37189a80a1a58f04b6bhkuang ExpectedTy = ExpectedTy.getCanonicalType(); 129b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian ActualTy = ActualTy.getCanonicalType(); 130b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (ExpectedTy == ActualTy) 131b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return V; 1326ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 1336ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // No adjustment is needed between Objective-C pointer types. 1341184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (ExpectedTy->isObjCObjectPointerType() && 1355ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ActualTy->isObjCObjectPointerType()) 1365ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang return V; 1375ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1385ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // C++ object pointers may need "derived-to-base" casts. 1391184aebb761cbeac9124c37189a80a1a58f04b6bhkuang const CXXRecordDecl *ExpectedClass = ExpectedTy->getPointeeCXXRecordDecl(); 1405ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const CXXRecordDecl *ActualClass = ActualTy->getPointeeCXXRecordDecl(); 1415ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (ExpectedClass && ActualClass) { 1421184aebb761cbeac9124c37189a80a1a58f04b6bhkuang CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1431184aebb761cbeac9124c37189a80a1a58f04b6bhkuang /*DetectVirtual=*/false); 1441184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (ActualClass->isDerivedFrom(ExpectedClass, Paths) && 1455ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang !Paths.isAmbiguous(ActualTy->getCanonicalTypeUnqualified())) { 1465ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang return StoreMgr.evalDerivedToBase(V, Paths.front()); 1475ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 1485ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 1495ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1505ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Unfortunately, Objective-C does not enforce that overridden methods have 1515ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // covariant return types, so we can't assert that that never happens. 1525ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Be safe and return UnknownVal(). 1535ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang return UnknownVal(); 1545ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang} 1555ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1565ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangvoid ExprEngine::removeDeadOnEndOfFunction(NodeBuilderContext& BC, 1575ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ExplodedNode *Pred, 1585ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ExplodedNodeSet &Dst) { 1595ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Find the last statement in the function and the corresponding basic block. 1605ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const Stmt *LastSt = 0; 1615ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const CFGBlock *Blk = 0; 1625ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang llvm::tie(LastSt, Blk) = getLastStmt(Pred); 1635ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (!Blk || !LastSt) { 1645ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang Dst.Add(Pred); 1655ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang return; 1665ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 1675ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1685ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Here, we destroy the current location context. We use the current 1695ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // function's entire body as a diagnostic statement, with which the program 1705ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // point will be associated. However, we only want to use LastStmt as a 1715ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // reference for what to clean up if it's a ReturnStmt; otherwise, everything 1725ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // is dead. 1735ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang SaveAndRestore<const NodeBuilderContext *> NodeContextRAII(currBldrCtx, &BC); 1745ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const LocationContext *LCtx = Pred->getLocationContext(); 1755ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang removeDead(Pred, Dst, dyn_cast<ReturnStmt>(LastSt), LCtx, 1765ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang LCtx->getAnalysisDeclContext()->getBody(), 1775ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ProgramPoint::PostStmtPurgeDeadSymbolsKind); 1785ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang} 1795ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 1805ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuangstatic bool wasDifferentDeclUsedForInlining(CallEventRef<> Call, 1815ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const StackFrameContext *calleeCtx) { 1825ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const Decl *RuntimeCallee = calleeCtx->getDecl(); 1835ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const Decl *StaticDecl = Call->getDecl(); 1845ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang assert(RuntimeCallee); 185b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (!StaticDecl) 186b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return true; 187b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return RuntimeCallee->getCanonicalDecl() != StaticDecl->getCanonicalDecl(); 188b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian} 189b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 190b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// Returns true if the CXXConstructExpr \p E was intended to construct a 191b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// prvalue for the region in \p V. 192b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// 193b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// Note that we can't just test for rvalue vs. glvalue because 194b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// CXXConstructExprs embedded in DeclStmts and initializers are considered 195b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// rvalues by the AST, and the analyzer would like to treat them as lvalues. 196b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanianstatic bool isTemporaryPRValue(const CXXConstructExpr *E, SVal V) { 197b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (E->isGLValue()) 198b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian return false; 199b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 2006ac915abcdb404a00d927fe6308a47fcf09d9519hkuang const MemRegion *MR = V.getAsRegion(); 2016ac915abcdb404a00d927fe6308a47fcf09d9519hkuang if (!MR) 2026ac915abcdb404a00d927fe6308a47fcf09d9519hkuang return false; 2036ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 2046ac915abcdb404a00d927fe6308a47fcf09d9519hkuang return isa<CXXTempObjectRegion>(MR); 2056ac915abcdb404a00d927fe6308a47fcf09d9519hkuang} 2066ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 2076ac915abcdb404a00d927fe6308a47fcf09d9519hkuang/// The call exit is simulated with a sequence of nodes, which occur between 2085ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang/// CallExitBegin and CallExitEnd. The following operations occur between the 2095ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang/// two program points: 2105ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang/// 1. CallExitBegin (triggers the start of call exit sequence) 2115ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang/// 2. Bind the return value 2121184aebb761cbeac9124c37189a80a1a58f04b6bhkuang/// 3. Run Remove dead bindings to clean up the dead symbols from the callee. 213b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// 4. CallExitEnd (switch to the caller context) 214b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian/// 5. PostStmt<CallExpr> 215b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanianvoid ExprEngine::processCallExit(ExplodedNode *CEBNode) { 216b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Step 1 CEBNode was generated before the call. 217b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 218b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const StackFrameContext *calleeCtx = 219b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian CEBNode->getLocationContext()->getCurrentStackFrame(); 220b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 221b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // The parent context might not be a stack frame, so make sure we 222b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // look up the first enclosing stack frame. 223b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const StackFrameContext *callerCtx = 224b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian calleeCtx->getParent()->getCurrentStackFrame(); 225b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 226b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const Stmt *CE = calleeCtx->getCallSite(); 227b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian ProgramStateRef state = CEBNode->getState(); 228b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Find the last statement in the function and the corresponding basic block. 229b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const Stmt *LastSt = 0; 230b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const CFGBlock *Blk = 0; 231b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian llvm::tie(LastSt, Blk) = getLastStmt(CEBNode); 232b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 233b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Generate a CallEvent /before/ cleaning the state, so that we can get the 234b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // correct value for 'this' (if necessary). 235b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian CallEventManager &CEMgr = getStateManager().getCallEventManager(); 236b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian CallEventRef<> Call = CEMgr.getCaller(calleeCtx, state); 237b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 238b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Step 2: generate node with bound return value: CEBNode -> BindedRetNode. 239b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 240b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // If the callee returns an expression, bind its value to CallExpr. 241b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (CE) { 242b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (const ReturnStmt *RS = dyn_cast_or_null<ReturnStmt>(LastSt)) { 2436ac915abcdb404a00d927fe6308a47fcf09d9519hkuang const LocationContext *LCtx = CEBNode->getLocationContext(); 2446ac915abcdb404a00d927fe6308a47fcf09d9519hkuang SVal V = state->getSVal(RS, LCtx); 2456ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 2466ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // Ensure that the return type matches the type of the returned Expr. 2476ac915abcdb404a00d927fe6308a47fcf09d9519hkuang if (wasDifferentDeclUsedForInlining(Call, calleeCtx)) { 2486ac915abcdb404a00d927fe6308a47fcf09d9519hkuang QualType ReturnedTy = 2496ac915abcdb404a00d927fe6308a47fcf09d9519hkuang CallEvent::getDeclaredResultType(calleeCtx->getDecl()); 2506ac915abcdb404a00d927fe6308a47fcf09d9519hkuang if (!ReturnedTy.isNull()) { 2516ac915abcdb404a00d927fe6308a47fcf09d9519hkuang if (const Expr *Ex = dyn_cast<Expr>(CE)) { 2526ac915abcdb404a00d927fe6308a47fcf09d9519hkuang V = adjustReturnValue(V, Ex->getType(), ReturnedTy, 2536ac915abcdb404a00d927fe6308a47fcf09d9519hkuang getStoreManager()); 2545ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 2555ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 2565ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 2575ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 2581184aebb761cbeac9124c37189a80a1a58f04b6bhkuang state = state->BindExpr(CE, callerCtx, V); 2595ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 260b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 2615ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Bind the constructed object value to CXXConstructExpr. 2625ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) { 2635ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang loc::MemRegionVal This = 2645ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang svalBuilder.getCXXThis(CCE->getConstructor()->getParent(), calleeCtx); 2651184aebb761cbeac9124c37189a80a1a58f04b6bhkuang SVal ThisV = state->getSVal(This); 2665ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 2675ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // If the constructed object is a temporary prvalue, get its bindings. 2685ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (isTemporaryPRValue(CCE, ThisV)) 2691184aebb761cbeac9124c37189a80a1a58f04b6bhkuang ThisV = state->getSVal(cast<Loc>(ThisV)); 2705ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 2715ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang state = state->BindExpr(CCE, callerCtx, ThisV); 2725ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 2735ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 2745ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 275b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Step 3: BindedRetNode -> CleanedNodes 2765ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // If we can find a statement and a block in the inlined function, run remove 2775ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // dead bindings before returning from the call. This is important to ensure 2785ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // that we report the issues such as leaks in the stack contexts in which 2795ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // they occurred. 280b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian ExplodedNodeSet CleanedNodes; 2811184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (LastSt && Blk && AMgr.options.AnalysisPurgeOpt != PurgeNone) { 2821184aebb761cbeac9124c37189a80a1a58f04b6bhkuang static SimpleProgramPointTag retValBind("ExprEngine : Bind Return Value"); 2835ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang PostStmt Loc(LastSt, calleeCtx, &retValBind); 2845ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang bool isNew; 285b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian ExplodedNode *BindedRetNode = G.getNode(Loc, state, false, &isNew); 286b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian BindedRetNode->addPredecessor(CEBNode, G); 2871184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (!isNew) 2885ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang return; 2895ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 2905ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang NodeBuilderContext Ctx(getCoreEngine(), Blk, BindedRetNode); 2915ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang currBldrCtx = &Ctx; 2921184aebb761cbeac9124c37189a80a1a58f04b6bhkuang // Here, we call the Symbol Reaper with 0 statement and callee location 2935ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // context, telling it to clean up everything in the callee's context 2941184aebb761cbeac9124c37189a80a1a58f04b6bhkuang // (and its children). We use the callee's function body as a diagnostic 2951184aebb761cbeac9124c37189a80a1a58f04b6bhkuang // statement, with which the program point will be associated. 296b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian removeDead(BindedRetNode, CleanedNodes, 0, calleeCtx, 297a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian calleeCtx->getAnalysisDeclContext()->getBody(), 2981184aebb761cbeac9124c37189a80a1a58f04b6bhkuang ProgramPoint::PostStmtPurgeDeadSymbolsKind); 2995ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang currBldrCtx = 0; 3005ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } else { 301b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian CleanedNodes.Add(CEBNode); 3025ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 3031184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 3041184aebb761cbeac9124c37189a80a1a58f04b6bhkuang for (ExplodedNodeSet::iterator I = CleanedNodes.begin(), 3055ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang E = CleanedNodes.end(); I != E; ++I) { 3065ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 3075ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // Step 4: Generate the CallExit and leave the callee's context. 3085ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang // CleanedNodes -> CEENode 3095ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang CallExitEnd Loc(calleeCtx, callerCtx); 3105ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang bool isNew; 3115ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ProgramStateRef CEEState = (*I == CEBNode) ? state : (*I)->getState(); 3125ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang ExplodedNode *CEENode = G.getNode(Loc, CEEState, false, &isNew); 3135ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang CEENode->addPredecessor(*I, G); 3145ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (!isNew) 3151184aebb761cbeac9124c37189a80a1a58f04b6bhkuang return; 316b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 317b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Step 5: Perform the post-condition check of the CallExpr and enqueue the 318b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // result onto the work list. 319b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // CEENode -> Dst -> WorkList 320b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), CEENode); 321b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian SaveAndRestore<const NodeBuilderContext*> NBCSave(currBldrCtx, 322b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian &Ctx); 323b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian SaveAndRestore<unsigned> CBISave(currStmtIdx, calleeCtx->getIndex()); 324b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 3251184aebb761cbeac9124c37189a80a1a58f04b6bhkuang CallEventRef<> UpdatedCall = Call.cloneWithState(CEEState); 326b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 327b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian ExplodedNodeSet DstPostCall; 328b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian getCheckerManager().runCheckersForPostCall(DstPostCall, CEENode, 329b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian *UpdatedCall, *this, 330b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian /*WasInlined=*/true); 331b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 3321184aebb761cbeac9124c37189a80a1a58f04b6bhkuang ExplodedNodeSet Dst; 3331184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(Call)) { 334b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian getCheckerManager().runCheckersForPostObjCMessage(Dst, DstPostCall, *Msg, 335b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian *this, 336b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian /*WasInlined=*/true); 337b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } else if (CE) { 3385ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang getCheckerManager().runCheckersForPostStmt(Dst, DstPostCall, CE, 339a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian *this, /*WasInlined=*/true); 340a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian } else { 341a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian Dst.insert(DstPostCall); 342a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian } 343a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 344a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // Enqueue the next element in the block. 345b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian for (ExplodedNodeSet::iterator PSI = Dst.begin(), PSE = Dst.end(); 346a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian PSI != PSE; ++PSI) { 347a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian Engine.getWorkList()->enqueue(*PSI, calleeCtx->getCallSiteBlock(), 3485ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang calleeCtx->getIndex()+1); 3495ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang } 3501184aebb761cbeac9124c37189a80a1a58f04b6bhkuang } 3511184aebb761cbeac9124c37189a80a1a58f04b6bhkuang} 352b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 353b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanianvoid ExprEngine::examineStackFrames(const Decl *D, const LocationContext *LCtx, 354b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian bool &IsRecursive, unsigned &StackDepth) { 355b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian IsRecursive = false; 356b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian StackDepth = 0; 357b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 358b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian while (LCtx) { 359b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LCtx)) { 360b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian const Decl *DI = SFC->getDecl(); 361b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 362b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Mark recursive (and mutually recursive) functions and always count 363b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // them when measuring the stack depth. 3645ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (DI == D) { 365a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian IsRecursive = true; 366a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian ++StackDepth; 367a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian LCtx = LCtx->getParent(); 368a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian continue; 3691184aebb761cbeac9124c37189a80a1a58f04b6bhkuang } 3701184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 371b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian // Do not count the small functions when determining the stack depth. 3721184aebb761cbeac9124c37189a80a1a58f04b6bhkuang AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(DI); 3731184aebb761cbeac9124c37189a80a1a58f04b6bhkuang const CFG *CalleeCFG = CalleeADC->getCFG(); 3741184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (CalleeCFG->getNumBlockIDs() > AMgr.options.getAlwaysInlineSize()) 3751184aebb761cbeac9124c37189a80a1a58f04b6bhkuang ++StackDepth; 376b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } 377b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian LCtx = LCtx->getParent(); 378b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } 379b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 380b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian} 3811184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 382b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanianstatic bool IsInStdNamespace(const FunctionDecl *FD) { 3835ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const DeclContext *DC = FD->getEnclosingNamespaceContext(); 3845ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC); 3855ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang if (!ND) 3865ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang return false; 3875ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang 3885ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang while (const DeclContext *Parent = ND->getParent()) { 3891184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (!isa<NamespaceDecl>(Parent)) 3901184aebb761cbeac9124c37189a80a1a58f04b6bhkuang break; 3911184aebb761cbeac9124c37189a80a1a58f04b6bhkuang ND = cast<NamespaceDecl>(Parent); 392 } 393 394 return ND->getName() == "std"; 395} 396 397// Determine if we should inline the call. 398bool ExprEngine::shouldInlineDecl(const Decl *D, ExplodedNode *Pred) { 399 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D); 400 const CFG *CalleeCFG = CalleeADC->getCFG(); 401 402 // It is possible that the CFG cannot be constructed. 403 // Be safe, and check if the CalleeCFG is valid. 404 if (!CalleeCFG) 405 return false; 406 407 bool IsRecursive = false; 408 unsigned StackDepth = 0; 409 examineStackFrames(D, Pred->getLocationContext(), IsRecursive, StackDepth); 410 if ((StackDepth >= AMgr.options.InlineMaxStackDepth) && 411 ((CalleeCFG->getNumBlockIDs() > AMgr.options.getAlwaysInlineSize()) 412 || IsRecursive)) 413 return false; 414 415 if (Engine.FunctionSummaries->hasReachedMaxBlockCount(D)) 416 return false; 417 418 if (CalleeCFG->getNumBlockIDs() > AMgr.options.getMaxInlinableSize()) 419 return false; 420 421 // Do not inline variadic calls (for now). 422 if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) { 423 if (BD->isVariadic()) 424 return false; 425 } 426 else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 427 if (FD->isVariadic()) 428 return false; 429 } 430 431 if (getContext().getLangOpts().CPlusPlus) { 432 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 433 // Conditionally allow the inlining of template functions. 434 if (!AMgr.options.mayInlineTemplateFunctions()) 435 if (FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate) 436 return false; 437 438 // Conditionally allow the inlining of C++ standard library functions. 439 if (!AMgr.options.mayInlineCXXStandardLibrary()) 440 if (getContext().getSourceManager().isInSystemHeader(FD->getLocation())) 441 if (IsInStdNamespace(FD)) 442 return false; 443 } 444 } 445 446 // It is possible that the live variables analysis cannot be 447 // run. If so, bail out. 448 if (!CalleeADC->getAnalysis<RelaxedLiveVariables>()) 449 return false; 450 451 if (Engine.FunctionSummaries->getNumTimesInlined(D) > 452 AMgr.options.getMaxTimesInlineLarge() && 453 CalleeCFG->getNumBlockIDs() > 13) { 454 NumReachedInlineCountMax++; 455 return false; 456 } 457 Engine.FunctionSummaries->bumpNumTimesInlined(D); 458 459 return true; 460} 461 462// The GDM component containing the dynamic dispatch bifurcation info. When 463// the exact type of the receiver is not known, we want to explore both paths - 464// one on which we do inline it and the other one on which we don't. This is 465// done to ensure we do not drop coverage. 466// This is the map from the receiver region to a bool, specifying either we 467// consider this region's information precise or not along the given path. 468namespace { 469 enum DynamicDispatchMode { 470 DynamicDispatchModeInlined = 1, 471 DynamicDispatchModeConservative 472 }; 473} 474REGISTER_TRAIT_WITH_PROGRAMSTATE(DynamicDispatchBifurcationMap, 475 CLANG_ENTO_PROGRAMSTATE_MAP(const MemRegion *, 476 unsigned)) 477 478bool ExprEngine::inlineCall(const CallEvent &Call, const Decl *D, 479 NodeBuilder &Bldr, ExplodedNode *Pred, 480 ProgramStateRef State) { 481 assert(D); 482 483 const LocationContext *CurLC = Pred->getLocationContext(); 484 const StackFrameContext *CallerSFC = CurLC->getCurrentStackFrame(); 485 const LocationContext *ParentOfCallee = 0; 486 487 AnalyzerOptions &Opts = getAnalysisManager().options; 488 489 // FIXME: Refactor this check into a hypothetical CallEvent::canInline. 490 switch (Call.getKind()) { 491 case CE_Function: 492 break; 493 case CE_CXXMember: 494 case CE_CXXMemberOperator: 495 if (!Opts.mayInlineCXXMemberFunction(CIMK_MemberFunctions)) 496 return false; 497 break; 498 case CE_CXXConstructor: { 499 if (!Opts.mayInlineCXXMemberFunction(CIMK_Constructors)) 500 return false; 501 502 const CXXConstructorCall &Ctor = cast<CXXConstructorCall>(Call); 503 504 // FIXME: We don't handle constructors or destructors for arrays properly. 505 const MemRegion *Target = Ctor.getCXXThisVal().getAsRegion(); 506 if (Target && isa<ElementRegion>(Target)) 507 return false; 508 509 // FIXME: This is a hack. We don't use the correct region for a new 510 // expression, so if we inline the constructor its result will just be 511 // thrown away. This short-term hack is tracked in <rdar://problem/12180598> 512 // and the longer-term possible fix is discussed in PR12014. 513 const CXXConstructExpr *CtorExpr = Ctor.getOriginExpr(); 514 if (const Stmt *Parent = CurLC->getParentMap().getParent(CtorExpr)) 515 if (isa<CXXNewExpr>(Parent)) 516 return false; 517 518 // Inlining constructors requires including initializers in the CFG. 519 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext(); 520 assert(ADC->getCFGBuildOptions().AddInitializers && "No CFG initializers"); 521 (void)ADC; 522 523 // If the destructor is trivial, it's always safe to inline the constructor. 524 if (Ctor.getDecl()->getParent()->hasTrivialDestructor()) 525 break; 526 527 // For other types, only inline constructors if destructor inlining is 528 // also enabled. 529 if (!Opts.mayInlineCXXMemberFunction(CIMK_Destructors)) 530 return false; 531 532 // FIXME: This is a hack. We don't handle temporary destructors 533 // right now, so we shouldn't inline their constructors. 534 if (CtorExpr->getConstructionKind() == CXXConstructExpr::CK_Complete) 535 if (!Target || !isa<DeclRegion>(Target)) 536 return false; 537 538 break; 539 } 540 case CE_CXXDestructor: { 541 if (!Opts.mayInlineCXXMemberFunction(CIMK_Destructors)) 542 return false; 543 544 // Inlining destructors requires building the CFG correctly. 545 const AnalysisDeclContext *ADC = CallerSFC->getAnalysisDeclContext(); 546 assert(ADC->getCFGBuildOptions().AddImplicitDtors && "No CFG destructors"); 547 (void)ADC; 548 549 const CXXDestructorCall &Dtor = cast<CXXDestructorCall>(Call); 550 551 // FIXME: We don't handle constructors or destructors for arrays properly. 552 const MemRegion *Target = Dtor.getCXXThisVal().getAsRegion(); 553 if (Target && isa<ElementRegion>(Target)) 554 return false; 555 556 break; 557 } 558 case CE_CXXAllocator: 559 // Do not inline allocators until we model deallocators. 560 // This is unfortunate, but basically necessary for smart pointers and such. 561 return false; 562 case CE_Block: { 563 const BlockDataRegion *BR = cast<BlockCall>(Call).getBlockRegion(); 564 assert(BR && "If we have the block definition we should have its region"); 565 AnalysisDeclContext *BlockCtx = AMgr.getAnalysisDeclContext(D); 566 ParentOfCallee = BlockCtx->getBlockInvocationContext(CallerSFC, 567 cast<BlockDecl>(D), 568 BR); 569 break; 570 } 571 case CE_ObjCMessage: 572 if (!Opts.mayInlineObjCMethod()) 573 return false; 574 AnalyzerOptions &Options = getAnalysisManager().options; 575 if (!(Options.getIPAMode() == IPAK_DynamicDispatch || 576 Options.getIPAMode() == IPAK_DynamicDispatchBifurcate)) 577 return false; 578 break; 579 } 580 581 if (!shouldInlineDecl(D, Pred)) 582 return false; 583 584 if (!ParentOfCallee) 585 ParentOfCallee = CallerSFC; 586 587 // This may be NULL, but that's fine. 588 const Expr *CallE = Call.getOriginExpr(); 589 590 // Construct a new stack frame for the callee. 591 AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D); 592 const StackFrameContext *CalleeSFC = 593 CalleeADC->getStackFrame(ParentOfCallee, CallE, 594 currBldrCtx->getBlock(), 595 currStmtIdx); 596 597 CallEnter Loc(CallE, CalleeSFC, CurLC); 598 599 // Construct a new state which contains the mapping from actual to 600 // formal arguments. 601 State = State->enterStackFrame(Call, CalleeSFC); 602 603 bool isNew; 604 if (ExplodedNode *N = G.getNode(Loc, State, false, &isNew)) { 605 N->addPredecessor(Pred, G); 606 if (isNew) 607 Engine.getWorkList()->enqueue(N); 608 } 609 610 // If we decided to inline the call, the successor has been manually 611 // added onto the work list so remove it from the node builder. 612 Bldr.takeNodes(Pred); 613 614 NumInlinedCalls++; 615 616 // Mark the decl as visited. 617 if (VisitedCallees) 618 VisitedCallees->insert(D); 619 620 return true; 621} 622 623static ProgramStateRef getInlineFailedState(ProgramStateRef State, 624 const Stmt *CallE) { 625 const void *ReplayState = State->get<ReplayWithoutInlining>(); 626 if (!ReplayState) 627 return 0; 628 629 assert(ReplayState == CallE && "Backtracked to the wrong call."); 630 (void)CallE; 631 632 return State->remove<ReplayWithoutInlining>(); 633} 634 635void ExprEngine::VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 636 ExplodedNodeSet &dst) { 637 // Perform the previsit of the CallExpr. 638 ExplodedNodeSet dstPreVisit; 639 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, CE, *this); 640 641 // Get the call in its initial state. We use this as a template to perform 642 // all the checks. 643 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 644 CallEventRef<> CallTemplate 645 = CEMgr.getSimpleCall(CE, Pred->getState(), Pred->getLocationContext()); 646 647 // Evaluate the function call. We try each of the checkers 648 // to see if the can evaluate the function call. 649 ExplodedNodeSet dstCallEvaluated; 650 for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end(); 651 I != E; ++I) { 652 evalCall(dstCallEvaluated, *I, *CallTemplate); 653 } 654 655 // Finally, perform the post-condition check of the CallExpr and store 656 // the created nodes in 'Dst'. 657 // Note that if the call was inlined, dstCallEvaluated will be empty. 658 // The post-CallExpr check will occur in processCallExit. 659 getCheckerManager().runCheckersForPostStmt(dst, dstCallEvaluated, CE, 660 *this); 661} 662 663void ExprEngine::evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred, 664 const CallEvent &Call) { 665 // WARNING: At this time, the state attached to 'Call' may be older than the 666 // state in 'Pred'. This is a minor optimization since CheckerManager will 667 // use an updated CallEvent instance when calling checkers, but if 'Call' is 668 // ever used directly in this function all callers should be updated to pass 669 // the most recent state. (It is probably not worth doing the work here since 670 // for some callers this will not be necessary.) 671 672 // Run any pre-call checks using the generic call interface. 673 ExplodedNodeSet dstPreVisit; 674 getCheckerManager().runCheckersForPreCall(dstPreVisit, Pred, Call, *this); 675 676 // Actually evaluate the function call. We try each of the checkers 677 // to see if the can evaluate the function call, and get a callback at 678 // defaultEvalCall if all of them fail. 679 ExplodedNodeSet dstCallEvaluated; 680 getCheckerManager().runCheckersForEvalCall(dstCallEvaluated, dstPreVisit, 681 Call, *this); 682 683 // Finally, run any post-call checks. 684 getCheckerManager().runCheckersForPostCall(Dst, dstCallEvaluated, 685 Call, *this); 686} 687 688ProgramStateRef ExprEngine::bindReturnValue(const CallEvent &Call, 689 const LocationContext *LCtx, 690 ProgramStateRef State) { 691 const Expr *E = Call.getOriginExpr(); 692 if (!E) 693 return State; 694 695 // Some method families have known return values. 696 if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(&Call)) { 697 switch (Msg->getMethodFamily()) { 698 default: 699 break; 700 case OMF_autorelease: 701 case OMF_retain: 702 case OMF_self: { 703 // These methods return their receivers. 704 return State->BindExpr(E, LCtx, Msg->getReceiverSVal()); 705 } 706 } 707 } else if (const CXXConstructorCall *C = dyn_cast<CXXConstructorCall>(&Call)){ 708 SVal ThisV = C->getCXXThisVal(); 709 710 // If the constructed object is a temporary prvalue, get its bindings. 711 if (isTemporaryPRValue(cast<CXXConstructExpr>(E), ThisV)) 712 ThisV = State->getSVal(cast<Loc>(ThisV)); 713 714 return State->BindExpr(E, LCtx, ThisV); 715 } 716 717 // Conjure a symbol if the return value is unknown. 718 QualType ResultTy = Call.getResultType(); 719 SValBuilder &SVB = getSValBuilder(); 720 unsigned Count = currBldrCtx->blockCount(); 721 SVal R = SVB.conjureSymbolVal(0, E, LCtx, ResultTy, Count); 722 return State->BindExpr(E, LCtx, R); 723} 724 725// Conservatively evaluate call by invalidating regions and binding 726// a conjured return value. 727void ExprEngine::conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr, 728 ExplodedNode *Pred, ProgramStateRef State) { 729 State = Call.invalidateRegions(currBldrCtx->blockCount(), State); 730 State = bindReturnValue(Call, Pred->getLocationContext(), State); 731 732 // And make the result node. 733 Bldr.generateNode(Call.getProgramPoint(), State, Pred); 734} 735 736static bool isEssentialToInline(const CallEvent &Call) { 737 const Decl *D = Call.getDecl(); 738 if (D) { 739 AnalysisDeclContext *AD = 740 Call.getLocationContext()->getAnalysisDeclContext()-> 741 getManager()->getContext(D); 742 743 // The auto-synthesized bodies are essential to inline as they are 744 // usually small and commonly used. 745 return AD->isBodyAutosynthesized(); 746 } 747 return false; 748} 749 750void ExprEngine::defaultEvalCall(NodeBuilder &Bldr, ExplodedNode *Pred, 751 const CallEvent &CallTemplate) { 752 // Make sure we have the most recent state attached to the call. 753 ProgramStateRef State = Pred->getState(); 754 CallEventRef<> Call = CallTemplate.cloneWithState(State); 755 756 if (HowToInline == Inline_None && !isEssentialToInline(CallTemplate)) { 757 conservativeEvalCall(*Call, Bldr, Pred, State); 758 return; 759 } 760 // Try to inline the call. 761 // The origin expression here is just used as a kind of checksum; 762 // this should still be safe even for CallEvents that don't come from exprs. 763 const Expr *E = Call->getOriginExpr(); 764 ProgramStateRef InlinedFailedState = getInlineFailedState(State, E); 765 766 if (InlinedFailedState) { 767 // If we already tried once and failed, make sure we don't retry later. 768 State = InlinedFailedState; 769 } else { 770 RuntimeDefinition RD = Call->getRuntimeDefinition(); 771 const Decl *D = RD.getDecl(); 772 if (D) { 773 if (RD.mayHaveOtherDefinitions()) { 774 AnalyzerOptions &Options = getAnalysisManager().options; 775 776 // Explore with and without inlining the call. 777 if (Options.getIPAMode() == IPAK_DynamicDispatchBifurcate) { 778 BifurcateCall(RD.getDispatchRegion(), *Call, D, Bldr, Pred); 779 return; 780 } 781 782 // Don't inline if we're not in any dynamic dispatch mode. 783 if (Options.getIPAMode() != IPAK_DynamicDispatch) { 784 conservativeEvalCall(*Call, Bldr, Pred, State); 785 return; 786 } 787 } 788 789 // We are not bifurcating and we do have a Decl, so just inline. 790 if (inlineCall(*Call, D, Bldr, Pred, State)) 791 return; 792 } 793 } 794 795 // If we can't inline it, handle the return value and invalidate the regions. 796 conservativeEvalCall(*Call, Bldr, Pred, State); 797} 798 799void ExprEngine::BifurcateCall(const MemRegion *BifurReg, 800 const CallEvent &Call, const Decl *D, 801 NodeBuilder &Bldr, ExplodedNode *Pred) { 802 assert(BifurReg); 803 BifurReg = BifurReg->StripCasts(); 804 805 // Check if we've performed the split already - note, we only want 806 // to split the path once per memory region. 807 ProgramStateRef State = Pred->getState(); 808 const unsigned *BState = 809 State->get<DynamicDispatchBifurcationMap>(BifurReg); 810 if (BState) { 811 // If we are on "inline path", keep inlining if possible. 812 if (*BState == DynamicDispatchModeInlined) 813 if (inlineCall(Call, D, Bldr, Pred, State)) 814 return; 815 // If inline failed, or we are on the path where we assume we 816 // don't have enough info about the receiver to inline, conjure the 817 // return value and invalidate the regions. 818 conservativeEvalCall(Call, Bldr, Pred, State); 819 return; 820 } 821 822 // If we got here, this is the first time we process a message to this 823 // region, so split the path. 824 ProgramStateRef IState = 825 State->set<DynamicDispatchBifurcationMap>(BifurReg, 826 DynamicDispatchModeInlined); 827 inlineCall(Call, D, Bldr, Pred, IState); 828 829 ProgramStateRef NoIState = 830 State->set<DynamicDispatchBifurcationMap>(BifurReg, 831 DynamicDispatchModeConservative); 832 conservativeEvalCall(Call, Bldr, Pred, NoIState); 833 834 NumOfDynamicDispatchPathSplits++; 835 return; 836} 837 838 839void ExprEngine::VisitReturnStmt(const ReturnStmt *RS, ExplodedNode *Pred, 840 ExplodedNodeSet &Dst) { 841 842 ExplodedNodeSet dstPreVisit; 843 getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, RS, *this); 844 845 StmtNodeBuilder B(dstPreVisit, Dst, *currBldrCtx); 846 847 if (RS->getRetValue()) { 848 for (ExplodedNodeSet::iterator it = dstPreVisit.begin(), 849 ei = dstPreVisit.end(); it != ei; ++it) { 850 B.generateNode(RS, *it, (*it)->getState()); 851 } 852 } 853} 854