| //===- CallEvent.cpp - Wrapper for all function and method calls ----------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| /// \file This file defines CallEvent and its subclasses, which represent path- |
| /// sensitive instances of different kinds of function and method calls |
| /// (C, C++, and Objective-C). |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclBase.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/ExprCXX.h" |
| #include "clang/AST/ExprObjC.h" |
| #include "clang/AST/ParentMap.h" |
| #include "clang/AST/Stmt.h" |
| #include "clang/AST/Type.h" |
| #include "clang/Analysis/AnalysisDeclContext.h" |
| #include "clang/Analysis/CFG.h" |
| #include "clang/Analysis/CFGStmtMap.h" |
| #include "clang/Analysis/PathDiagnostic.h" |
| #include "clang/Analysis/ProgramPoint.h" |
| #include "clang/CrossTU/CrossTranslationUnit.h" |
| #include "clang/Basic/IdentifierTable.h" |
| #include "clang/Basic/LLVM.h" |
| #include "clang/Basic/SourceLocation.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/Specifiers.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeInfo.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h" |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/None.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/ADT/PointerIntPair.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/Support/Casting.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <cassert> |
| #include <utility> |
| |
| #define DEBUG_TYPE "static-analyzer-call-event" |
| |
| using namespace clang; |
| using namespace ento; |
| |
| QualType CallEvent::getResultType() const { |
| ASTContext &Ctx = getState()->getStateManager().getContext(); |
| const Expr *E = getOriginExpr(); |
| if (!E) |
| return Ctx.VoidTy; |
| assert(E); |
| |
| QualType ResultTy = E->getType(); |
| |
| // A function that returns a reference to 'int' will have a result type |
| // of simply 'int'. Check the origin expr's value kind to recover the |
| // proper type. |
| switch (E->getValueKind()) { |
| case VK_LValue: |
| ResultTy = Ctx.getLValueReferenceType(ResultTy); |
| break; |
| case VK_XValue: |
| ResultTy = Ctx.getRValueReferenceType(ResultTy); |
| break; |
| case VK_RValue: |
| // No adjustment is necessary. |
| break; |
| } |
| |
| return ResultTy; |
| } |
| |
| static bool isCallback(QualType T) { |
| // If a parameter is a block or a callback, assume it can modify pointer. |
| if (T->isBlockPointerType() || |
| T->isFunctionPointerType() || |
| T->isObjCSelType()) |
| return true; |
| |
| // Check if a callback is passed inside a struct (for both, struct passed by |
| // reference and by value). Dig just one level into the struct for now. |
| |
| if (T->isAnyPointerType() || T->isReferenceType()) |
| T = T->getPointeeType(); |
| |
| if (const RecordType *RT = T->getAsStructureType()) { |
| const RecordDecl *RD = RT->getDecl(); |
| for (const auto *I : RD->fields()) { |
| QualType FieldT = I->getType(); |
| if (FieldT->isBlockPointerType() || FieldT->isFunctionPointerType()) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| static bool isVoidPointerToNonConst(QualType T) { |
| if (const auto *PT = T->getAs<PointerType>()) { |
| QualType PointeeTy = PT->getPointeeType(); |
| if (PointeeTy.isConstQualified()) |
| return false; |
| return PointeeTy->isVoidType(); |
| } else |
| return false; |
| } |
| |
| bool CallEvent::hasNonNullArgumentsWithType(bool (*Condition)(QualType)) const { |
| unsigned NumOfArgs = getNumArgs(); |
| |
| // If calling using a function pointer, assume the function does not |
| // satisfy the callback. |
| // TODO: We could check the types of the arguments here. |
| if (!getDecl()) |
| return false; |
| |
| unsigned Idx = 0; |
| for (CallEvent::param_type_iterator I = param_type_begin(), |
| E = param_type_end(); |
| I != E && Idx < NumOfArgs; ++I, ++Idx) { |
| // If the parameter is 0, it's harmless. |
| if (getArgSVal(Idx).isZeroConstant()) |
| continue; |
| |
| if (Condition(*I)) |
| return true; |
| } |
| return false; |
| } |
| |
| bool CallEvent::hasNonZeroCallbackArg() const { |
| return hasNonNullArgumentsWithType(isCallback); |
| } |
| |
| bool CallEvent::hasVoidPointerToNonConstArg() const { |
| return hasNonNullArgumentsWithType(isVoidPointerToNonConst); |
| } |
| |
| bool CallEvent::isGlobalCFunction(StringRef FunctionName) const { |
| const auto *FD = dyn_cast_or_null<FunctionDecl>(getDecl()); |
| if (!FD) |
| return false; |
| |
| return CheckerContext::isCLibraryFunction(FD, FunctionName); |
| } |
| |
| AnalysisDeclContext *CallEvent::getCalleeAnalysisDeclContext() const { |
| const Decl *D = getDecl(); |
| if (!D) |
| return nullptr; |
| |
| // TODO: For now we skip functions without definitions, even if we have |
| // our own getDecl(), because it's hard to find out which re-declaration |
| // is going to be used, and usually clients don't really care about this |
| // situation because there's a loss of precision anyway because we cannot |
| // inline the call. |
| RuntimeDefinition RD = getRuntimeDefinition(); |
| if (!RD.getDecl()) |
| return nullptr; |
| |
| AnalysisDeclContext *ADC = |
| LCtx->getAnalysisDeclContext()->getManager()->getContext(D); |
| |
| // TODO: For now we skip virtual functions, because this also rises |
| // the problem of which decl to use, but now it's across different classes. |
| if (RD.mayHaveOtherDefinitions() || RD.getDecl() != ADC->getDecl()) |
| return nullptr; |
| |
| return ADC; |
| } |
| |
| const StackFrameContext * |
| CallEvent::getCalleeStackFrame(unsigned BlockCount) const { |
| AnalysisDeclContext *ADC = getCalleeAnalysisDeclContext(); |
| if (!ADC) |
| return nullptr; |
| |
| const Expr *E = getOriginExpr(); |
| if (!E) |
| return nullptr; |
| |
| // Recover CFG block via reverse lookup. |
| // TODO: If we were to keep CFG element information as part of the CallEvent |
| // instead of doing this reverse lookup, we would be able to build the stack |
| // frame for non-expression-based calls, and also we wouldn't need the reverse |
| // lookup. |
| CFGStmtMap *Map = LCtx->getAnalysisDeclContext()->getCFGStmtMap(); |
| const CFGBlock *B = Map->getBlock(E); |
| assert(B); |
| |
| // Also recover CFG index by scanning the CFG block. |
| unsigned Idx = 0, Sz = B->size(); |
| for (; Idx < Sz; ++Idx) |
| if (auto StmtElem = (*B)[Idx].getAs<CFGStmt>()) |
| if (StmtElem->getStmt() == E) |
| break; |
| assert(Idx < Sz); |
| |
| return ADC->getManager()->getStackFrame(ADC, LCtx, E, B, BlockCount, Idx); |
| } |
| |
| const VarRegion *CallEvent::getParameterLocation(unsigned Index, |
| unsigned BlockCount) const { |
| const StackFrameContext *SFC = getCalleeStackFrame(BlockCount); |
| // We cannot construct a VarRegion without a stack frame. |
| if (!SFC) |
| return nullptr; |
| |
| // Retrieve parameters of the definition, which are different from |
| // CallEvent's parameters() because getDecl() isn't necessarily |
| // the definition. SFC contains the definition that would be used |
| // during analysis. |
| const Decl *D = SFC->getDecl(); |
| |
| // TODO: Refactor into a virtual method of CallEvent, like parameters(). |
| const ParmVarDecl *PVD = nullptr; |
| if (const auto *FD = dyn_cast<FunctionDecl>(D)) |
| PVD = FD->parameters()[Index]; |
| else if (const auto *BD = dyn_cast<BlockDecl>(D)) |
| PVD = BD->parameters()[Index]; |
| else if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) |
| PVD = MD->parameters()[Index]; |
| else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D)) |
| PVD = CD->parameters()[Index]; |
| assert(PVD && "Unexpected Decl kind!"); |
| |
| const VarRegion *VR = |
| State->getStateManager().getRegionManager().getVarRegion(PVD, SFC); |
| |
| // This sanity check would fail if our parameter declaration doesn't |
| // correspond to the stack frame's function declaration. |
| assert(VR->getStackFrame() == SFC); |
| |
| return VR; |
| } |
| |
| /// Returns true if a type is a pointer-to-const or reference-to-const |
| /// with no further indirection. |
| static bool isPointerToConst(QualType Ty) { |
| QualType PointeeTy = Ty->getPointeeType(); |
| if (PointeeTy == QualType()) |
| return false; |
| if (!PointeeTy.isConstQualified()) |
| return false; |
| if (PointeeTy->isAnyPointerType()) |
| return false; |
| return true; |
| } |
| |
| // Try to retrieve the function declaration and find the function parameter |
| // types which are pointers/references to a non-pointer const. |
| // We will not invalidate the corresponding argument regions. |
| static void findPtrToConstParams(llvm::SmallSet<unsigned, 4> &PreserveArgs, |
| const CallEvent &Call) { |
| unsigned Idx = 0; |
| for (CallEvent::param_type_iterator I = Call.param_type_begin(), |
| E = Call.param_type_end(); |
| I != E; ++I, ++Idx) { |
| if (isPointerToConst(*I)) |
| PreserveArgs.insert(Idx); |
| } |
| } |
| |
| ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount, |
| ProgramStateRef Orig) const { |
| ProgramStateRef Result = (Orig ? Orig : getState()); |
| |
| // Don't invalidate anything if the callee is marked pure/const. |
| if (const Decl *callee = getDecl()) |
| if (callee->hasAttr<PureAttr>() || callee->hasAttr<ConstAttr>()) |
| return Result; |
| |
| SmallVector<SVal, 8> ValuesToInvalidate; |
| RegionAndSymbolInvalidationTraits ETraits; |
| |
| getExtraInvalidatedValues(ValuesToInvalidate, &ETraits); |
| |
| // Indexes of arguments whose values will be preserved by the call. |
| llvm::SmallSet<unsigned, 4> PreserveArgs; |
| if (!argumentsMayEscape()) |
| findPtrToConstParams(PreserveArgs, *this); |
| |
| for (unsigned Idx = 0, Count = getNumArgs(); Idx != Count; ++Idx) { |
| // Mark this region for invalidation. We batch invalidate regions |
| // below for efficiency. |
| if (PreserveArgs.count(Idx)) |
| if (const MemRegion *MR = getArgSVal(Idx).getAsRegion()) |
| ETraits.setTrait(MR->getBaseRegion(), |
| RegionAndSymbolInvalidationTraits::TK_PreserveContents); |
| // TODO: Factor this out + handle the lower level const pointers. |
| |
| ValuesToInvalidate.push_back(getArgSVal(Idx)); |
| |
| // If a function accepts an object by argument (which would of course be a |
| // temporary that isn't lifetime-extended), invalidate the object itself, |
| // not only other objects reachable from it. This is necessary because the |
| // destructor has access to the temporary object after the call. |
| // TODO: Support placement arguments once we start |
| // constructing them directly. |
| // TODO: This is unnecessary when there's no destructor, but that's |
| // currently hard to figure out. |
| if (getKind() != CE_CXXAllocator) |
| if (isArgumentConstructedDirectly(Idx)) |
| if (auto AdjIdx = getAdjustedParameterIndex(Idx)) |
| if (const VarRegion *VR = getParameterLocation(*AdjIdx, BlockCount)) |
| ValuesToInvalidate.push_back(loc::MemRegionVal(VR)); |
| } |
| |
| // Invalidate designated regions using the batch invalidation API. |
| // NOTE: Even if RegionsToInvalidate is empty, we may still invalidate |
| // global variables. |
| return Result->invalidateRegions(ValuesToInvalidate, getOriginExpr(), |
| BlockCount, getLocationContext(), |
| /*CausedByPointerEscape*/ true, |
| /*Symbols=*/nullptr, this, &ETraits); |
| } |
| |
| ProgramPoint CallEvent::getProgramPoint(bool IsPreVisit, |
| const ProgramPointTag *Tag) const { |
| if (const Expr *E = getOriginExpr()) { |
| if (IsPreVisit) |
| return PreStmt(E, getLocationContext(), Tag); |
| return PostStmt(E, getLocationContext(), Tag); |
| } |
| |
| const Decl *D = getDecl(); |
| assert(D && "Cannot get a program point without a statement or decl"); |
| |
| SourceLocation Loc = getSourceRange().getBegin(); |
| if (IsPreVisit) |
| return PreImplicitCall(D, Loc, getLocationContext(), Tag); |
| return PostImplicitCall(D, Loc, getLocationContext(), Tag); |
| } |
| |
| bool CallEvent::isCalled(const CallDescription &CD) const { |
| // FIXME: Add ObjC Message support. |
| if (getKind() == CE_ObjCMessage) |
| return false; |
| |
| const IdentifierInfo *II = getCalleeIdentifier(); |
| if (!II) |
| return false; |
| const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(getDecl()); |
| if (!FD) |
| return false; |
| |
| if (CD.Flags & CDF_MaybeBuiltin) { |
| return CheckerContext::isCLibraryFunction(FD, CD.getFunctionName()) && |
| (!CD.RequiredArgs || CD.RequiredArgs <= getNumArgs()) && |
| (!CD.RequiredParams || CD.RequiredParams <= parameters().size()); |
| } |
| |
| if (!CD.IsLookupDone) { |
| CD.IsLookupDone = true; |
| CD.II = &getState()->getStateManager().getContext().Idents.get( |
| CD.getFunctionName()); |
| } |
| |
| if (II != CD.II) |
| return false; |
| |
| // If CallDescription provides prefix names, use them to improve matching |
| // accuracy. |
| if (CD.QualifiedName.size() > 1 && FD) { |
| const DeclContext *Ctx = FD->getDeclContext(); |
| // See if we'll be able to match them all. |
| size_t NumUnmatched = CD.QualifiedName.size() - 1; |
| for (; Ctx && isa<NamedDecl>(Ctx); Ctx = Ctx->getParent()) { |
| if (NumUnmatched == 0) |
| break; |
| |
| if (const auto *ND = dyn_cast<NamespaceDecl>(Ctx)) { |
| if (ND->getName() == CD.QualifiedName[NumUnmatched - 1]) |
| --NumUnmatched; |
| continue; |
| } |
| |
| if (const auto *RD = dyn_cast<RecordDecl>(Ctx)) { |
| if (RD->getName() == CD.QualifiedName[NumUnmatched - 1]) |
| --NumUnmatched; |
| continue; |
| } |
| } |
| |
| if (NumUnmatched > 0) |
| return false; |
| } |
| |
| return (!CD.RequiredArgs || CD.RequiredArgs == getNumArgs()) && |
| (!CD.RequiredParams || CD.RequiredParams == parameters().size()); |
| } |
| |
| SVal CallEvent::getArgSVal(unsigned Index) const { |
| const Expr *ArgE = getArgExpr(Index); |
| if (!ArgE) |
| return UnknownVal(); |
| return getSVal(ArgE); |
| } |
| |
| SourceRange CallEvent::getArgSourceRange(unsigned Index) const { |
| const Expr *ArgE = getArgExpr(Index); |
| if (!ArgE) |
| return {}; |
| return ArgE->getSourceRange(); |
| } |
| |
| SVal CallEvent::getReturnValue() const { |
| const Expr *E = getOriginExpr(); |
| if (!E) |
| return UndefinedVal(); |
| return getSVal(E); |
| } |
| |
| LLVM_DUMP_METHOD void CallEvent::dump() const { dump(llvm::errs()); } |
| |
| void CallEvent::dump(raw_ostream &Out) const { |
| ASTContext &Ctx = getState()->getStateManager().getContext(); |
| if (const Expr *E = getOriginExpr()) { |
| E->printPretty(Out, nullptr, Ctx.getPrintingPolicy()); |
| Out << "\n"; |
| return; |
| } |
| |
| if (const Decl *D = getDecl()) { |
| Out << "Call to "; |
| D->print(Out, Ctx.getPrintingPolicy()); |
| return; |
| } |
| |
| // FIXME: a string representation of the kind would be nice. |
| Out << "Unknown call (type " << getKind() << ")"; |
| } |
| |
| bool CallEvent::isCallStmt(const Stmt *S) { |
| return isa<CallExpr>(S) || isa<ObjCMessageExpr>(S) |
| || isa<CXXConstructExpr>(S) |
| || isa<CXXNewExpr>(S); |
| } |
| |
| QualType CallEvent::getDeclaredResultType(const Decl *D) { |
| assert(D); |
| if (const auto *FD = dyn_cast<FunctionDecl>(D)) |
| return FD->getReturnType(); |
| if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) |
| return MD->getReturnType(); |
| if (const auto *BD = dyn_cast<BlockDecl>(D)) { |
| // Blocks are difficult because the return type may not be stored in the |
| // BlockDecl itself. The AST should probably be enhanced, but for now we |
| // just do what we can. |
| // If the block is declared without an explicit argument list, the |
| // signature-as-written just includes the return type, not the entire |
| // function type. |
| // FIXME: All blocks should have signatures-as-written, even if the return |
| // type is inferred. (That's signified with a dependent result type.) |
| if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten()) { |
| QualType Ty = TSI->getType(); |
| if (const FunctionType *FT = Ty->getAs<FunctionType>()) |
| Ty = FT->getReturnType(); |
| if (!Ty->isDependentType()) |
| return Ty; |
| } |
| |
| return {}; |
| } |
| |
| llvm_unreachable("unknown callable kind"); |
| } |
| |
| bool CallEvent::isVariadic(const Decl *D) { |
| assert(D); |
| |
| if (const auto *FD = dyn_cast<FunctionDecl>(D)) |
| return FD->isVariadic(); |
| if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) |
| return MD->isVariadic(); |
| if (const auto *BD = dyn_cast<BlockDecl>(D)) |
| return BD->isVariadic(); |
| |
| llvm_unreachable("unknown callable kind"); |
| } |
| |
| static void addParameterValuesToBindings(const StackFrameContext *CalleeCtx, |
| CallEvent::BindingsTy &Bindings, |
| SValBuilder &SVB, |
| const CallEvent &Call, |
| ArrayRef<ParmVarDecl*> parameters) { |
| MemRegionManager &MRMgr = SVB.getRegionManager(); |
| |
| // If the function has fewer parameters than the call has arguments, we simply |
| // do not bind any values to them. |
| unsigned NumArgs = Call.getNumArgs(); |
| unsigned Idx = 0; |
| ArrayRef<ParmVarDecl*>::iterator I = parameters.begin(), E = parameters.end(); |
| for (; I != E && Idx < NumArgs; ++I, ++Idx) { |
| const ParmVarDecl *ParamDecl = *I; |
| assert(ParamDecl && "Formal parameter has no decl?"); |
| |
| // TODO: Support allocator calls. |
| if (Call.getKind() != CE_CXXAllocator) |
| if (Call.isArgumentConstructedDirectly(Idx)) |
| continue; |
| |
| // TODO: Allocators should receive the correct size and possibly alignment, |
| // determined in compile-time but not represented as arg-expressions, |
| // which makes getArgSVal() fail and return UnknownVal. |
| SVal ArgVal = Call.getArgSVal(Idx); |
| if (!ArgVal.isUnknown()) { |
| Loc ParamLoc = SVB.makeLoc(MRMgr.getVarRegion(ParamDecl, CalleeCtx)); |
| Bindings.push_back(std::make_pair(ParamLoc, ArgVal)); |
| } |
| } |
| |
| // FIXME: Variadic arguments are not handled at all right now. |
| } |
| |
| ArrayRef<ParmVarDecl*> AnyFunctionCall::parameters() const { |
| const FunctionDecl *D = getDecl(); |
| if (!D) |
| return None; |
| return D->parameters(); |
| } |
| |
| RuntimeDefinition AnyFunctionCall::getRuntimeDefinition() const { |
| const FunctionDecl *FD = getDecl(); |
| if (!FD) |
| return {}; |
| |
| // Note that the AnalysisDeclContext will have the FunctionDecl with |
| // the definition (if one exists). |
| AnalysisDeclContext *AD = |
| getLocationContext()->getAnalysisDeclContext()-> |
| getManager()->getContext(FD); |
| bool IsAutosynthesized; |
| Stmt* Body = AD->getBody(IsAutosynthesized); |
| LLVM_DEBUG({ |
| if (IsAutosynthesized) |
| llvm::dbgs() << "Using autosynthesized body for " << FD->getName() |
| << "\n"; |
| }); |
| if (Body) { |
| const Decl* Decl = AD->getDecl(); |
| return RuntimeDefinition(Decl); |
| } |
| |
| SubEngine &Engine = getState()->getStateManager().getOwningEngine(); |
| AnalyzerOptions &Opts = Engine.getAnalysisManager().options; |
| |
| // Try to get CTU definition only if CTUDir is provided. |
| if (!Opts.IsNaiveCTUEnabled) |
| return {}; |
| |
| cross_tu::CrossTranslationUnitContext &CTUCtx = |
| *Engine.getCrossTranslationUnitContext(); |
| llvm::Expected<const FunctionDecl *> CTUDeclOrError = |
| CTUCtx.getCrossTUDefinition(FD, Opts.CTUDir, Opts.CTUIndexName, |
| Opts.DisplayCTUProgress); |
| |
| if (!CTUDeclOrError) { |
| handleAllErrors(CTUDeclOrError.takeError(), |
| [&](const cross_tu::IndexError &IE) { |
| CTUCtx.emitCrossTUDiagnostics(IE); |
| }); |
| return {}; |
| } |
| |
| return RuntimeDefinition(*CTUDeclOrError); |
| } |
| |
| void AnyFunctionCall::getInitialStackFrameContents( |
| const StackFrameContext *CalleeCtx, |
| BindingsTy &Bindings) const { |
| const auto *D = cast<FunctionDecl>(CalleeCtx->getDecl()); |
| SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); |
| addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this, |
| D->parameters()); |
| } |
| |
| bool AnyFunctionCall::argumentsMayEscape() const { |
| if (CallEvent::argumentsMayEscape() || hasVoidPointerToNonConstArg()) |
| return true; |
| |
| const FunctionDecl *D = getDecl(); |
| if (!D) |
| return true; |
| |
| const IdentifierInfo *II = D->getIdentifier(); |
| if (!II) |
| return false; |
| |
| // This set of "escaping" APIs is |
| |
| // - 'int pthread_setspecific(ptheread_key k, const void *)' stores a |
| // value into thread local storage. The value can later be retrieved with |
| // 'void *ptheread_getspecific(pthread_key)'. So even thought the |
| // parameter is 'const void *', the region escapes through the call. |
| if (II->isStr("pthread_setspecific")) |
| return true; |
| |
| // - xpc_connection_set_context stores a value which can be retrieved later |
| // with xpc_connection_get_context. |
| if (II->isStr("xpc_connection_set_context")) |
| return true; |
| |
| // - funopen - sets a buffer for future IO calls. |
| if (II->isStr("funopen")) |
| return true; |
| |
| // - __cxa_demangle - can reallocate memory and can return the pointer to |
| // the input buffer. |
| if (II->isStr("__cxa_demangle")) |
| return true; |
| |
| StringRef FName = II->getName(); |
| |
| // - CoreFoundation functions that end with "NoCopy" can free a passed-in |
| // buffer even if it is const. |
| if (FName.endswith("NoCopy")) |
| return true; |
| |
| // - NSXXInsertXX, for example NSMapInsertIfAbsent, since they can |
| // be deallocated by NSMapRemove. |
| if (FName.startswith("NS") && (FName.find("Insert") != StringRef::npos)) |
| return true; |
| |
| // - Many CF containers allow objects to escape through custom |
| // allocators/deallocators upon container construction. (PR12101) |
| if (FName.startswith("CF") || FName.startswith("CG")) { |
| return StrInStrNoCase(FName, "InsertValue") != StringRef::npos || |
| StrInStrNoCase(FName, "AddValue") != StringRef::npos || |
| StrInStrNoCase(FName, "SetValue") != StringRef::npos || |
| StrInStrNoCase(FName, "WithData") != StringRef::npos || |
| StrInStrNoCase(FName, "AppendValue") != StringRef::npos || |
| StrInStrNoCase(FName, "SetAttribute") != StringRef::npos; |
| } |
| |
| return false; |
| } |
| |
| const FunctionDecl *SimpleFunctionCall::getDecl() const { |
| const FunctionDecl *D = getOriginExpr()->getDirectCallee(); |
| if (D) |
| return D; |
| |
| return getSVal(getOriginExpr()->getCallee()).getAsFunctionDecl(); |
| } |
| |
| const FunctionDecl *CXXInstanceCall::getDecl() const { |
| const auto *CE = cast_or_null<CallExpr>(getOriginExpr()); |
| if (!CE) |
| return AnyFunctionCall::getDecl(); |
| |
| const FunctionDecl *D = CE->getDirectCallee(); |
| if (D) |
| return D; |
| |
| return getSVal(CE->getCallee()).getAsFunctionDecl(); |
| } |
| |
| void CXXInstanceCall::getExtraInvalidatedValues( |
| ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const { |
| SVal ThisVal = getCXXThisVal(); |
| Values.push_back(ThisVal); |
| |
| // Don't invalidate if the method is const and there are no mutable fields. |
| if (const auto *D = cast_or_null<CXXMethodDecl>(getDecl())) { |
| if (!D->isConst()) |
| return; |
| // Get the record decl for the class of 'This'. D->getParent() may return a |
| // base class decl, rather than the class of the instance which needs to be |
| // checked for mutable fields. |
| // TODO: We might as well look at the dynamic type of the object. |
| const Expr *Ex = getCXXThisExpr()->ignoreParenBaseCasts(); |
| QualType T = Ex->getType(); |
| if (T->isPointerType()) // Arrow or implicit-this syntax? |
| T = T->getPointeeType(); |
| const CXXRecordDecl *ParentRecord = T->getAsCXXRecordDecl(); |
| assert(ParentRecord); |
| if (ParentRecord->hasMutableFields()) |
| return; |
| // Preserve CXXThis. |
| const MemRegion *ThisRegion = ThisVal.getAsRegion(); |
| if (!ThisRegion) |
| return; |
| |
| ETraits->setTrait(ThisRegion->getBaseRegion(), |
| RegionAndSymbolInvalidationTraits::TK_PreserveContents); |
| } |
| } |
| |
| SVal CXXInstanceCall::getCXXThisVal() const { |
| const Expr *Base = getCXXThisExpr(); |
| // FIXME: This doesn't handle an overloaded ->* operator. |
| if (!Base) |
| return UnknownVal(); |
| |
| SVal ThisVal = getSVal(Base); |
| assert(ThisVal.isUnknownOrUndef() || ThisVal.getAs<Loc>()); |
| return ThisVal; |
| } |
| |
| RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const { |
| // Do we have a decl at all? |
| const Decl *D = getDecl(); |
| if (!D) |
| return {}; |
| |
| // If the method is non-virtual, we know we can inline it. |
| const auto *MD = cast<CXXMethodDecl>(D); |
| if (!MD->isVirtual()) |
| return AnyFunctionCall::getRuntimeDefinition(); |
| |
| // Do we know the implicit 'this' object being called? |
| const MemRegion *R = getCXXThisVal().getAsRegion(); |
| if (!R) |
| return {}; |
| |
| // Do we know anything about the type of 'this'? |
| DynamicTypeInfo DynType = getDynamicTypeInfo(getState(), R); |
| if (!DynType.isValid()) |
| return {}; |
| |
| // Is the type a C++ class? (This is mostly a defensive check.) |
| QualType RegionType = DynType.getType()->getPointeeType(); |
| assert(!RegionType.isNull() && "DynamicTypeInfo should always be a pointer."); |
| |
| const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl(); |
| if (!RD || !RD->hasDefinition()) |
| return {}; |
| |
| // Find the decl for this method in that class. |
| const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true); |
| if (!Result) { |
| // We might not even get the original statically-resolved method due to |
| // some particularly nasty casting (e.g. casts to sister classes). |
| // However, we should at least be able to search up and down our own class |
| // hierarchy, and some real bugs have been caught by checking this. |
| assert(!RD->isDerivedFrom(MD->getParent()) && "Couldn't find known method"); |
| |
| // FIXME: This is checking that our DynamicTypeInfo is at least as good as |
| // the static type. However, because we currently don't update |
| // DynamicTypeInfo when an object is cast, we can't actually be sure the |
| // DynamicTypeInfo is up to date. This assert should be re-enabled once |
| // this is fixed. <rdar://problem/12287087> |
| //assert(!MD->getParent()->isDerivedFrom(RD) && "Bad DynamicTypeInfo"); |
| |
| return {}; |
| } |
| |
| // Does the decl that we found have an implementation? |
| const FunctionDecl *Definition; |
| if (!Result->hasBody(Definition)) { |
| if (!DynType.canBeASubClass()) |
| return AnyFunctionCall::getRuntimeDefinition(); |
| return {}; |
| } |
| |
| // We found a definition. If we're not sure that this devirtualization is |
| // actually what will happen at runtime, make sure to provide the region so |
| // that ExprEngine can decide what to do with it. |
| if (DynType.canBeASubClass()) |
| return RuntimeDefinition(Definition, R->StripCasts()); |
| return RuntimeDefinition(Definition, /*DispatchRegion=*/nullptr); |
| } |
| |
| void CXXInstanceCall::getInitialStackFrameContents( |
| const StackFrameContext *CalleeCtx, |
| BindingsTy &Bindings) const { |
| AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings); |
| |
| // Handle the binding of 'this' in the new stack frame. |
| SVal ThisVal = getCXXThisVal(); |
| if (!ThisVal.isUnknown()) { |
| ProgramStateManager &StateMgr = getState()->getStateManager(); |
| SValBuilder &SVB = StateMgr.getSValBuilder(); |
| |
| const auto *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl()); |
| Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx); |
| |
| // If we devirtualized to a different member function, we need to make sure |
| // we have the proper layering of CXXBaseObjectRegions. |
| if (MD->getCanonicalDecl() != getDecl()->getCanonicalDecl()) { |
| ASTContext &Ctx = SVB.getContext(); |
| const CXXRecordDecl *Class = MD->getParent(); |
| QualType Ty = Ctx.getPointerType(Ctx.getRecordType(Class)); |
| |
| // FIXME: CallEvent maybe shouldn't be directly accessing StoreManager. |
| bool Failed; |
| ThisVal = StateMgr.getStoreManager().attemptDownCast(ThisVal, Ty, Failed); |
| if (Failed) { |
| // We might have suffered some sort of placement new earlier, so |
| // we're constructing in a completely unexpected storage. |
| // Fall back to a generic pointer cast for this-value. |
| const CXXMethodDecl *StaticMD = cast<CXXMethodDecl>(getDecl()); |
| const CXXRecordDecl *StaticClass = StaticMD->getParent(); |
| QualType StaticTy = Ctx.getPointerType(Ctx.getRecordType(StaticClass)); |
| ThisVal = SVB.evalCast(ThisVal, Ty, StaticTy); |
| } |
| } |
| |
| if (!ThisVal.isUnknown()) |
| Bindings.push_back(std::make_pair(ThisLoc, ThisVal)); |
| } |
| } |
| |
| const Expr *CXXMemberCall::getCXXThisExpr() const { |
| return getOriginExpr()->getImplicitObjectArgument(); |
| } |
| |
| RuntimeDefinition CXXMemberCall::getRuntimeDefinition() const { |
| // C++11 [expr.call]p1: ...If the selected function is non-virtual, or if the |
| // id-expression in the class member access expression is a qualified-id, |
| // that function is called. Otherwise, its final overrider in the dynamic type |
| // of the object expression is called. |
| if (const auto *ME = dyn_cast<MemberExpr>(getOriginExpr()->getCallee())) |
| if (ME->hasQualifier()) |
| return AnyFunctionCall::getRuntimeDefinition(); |
| |
| return CXXInstanceCall::getRuntimeDefinition(); |
| } |
| |
| const Expr *CXXMemberOperatorCall::getCXXThisExpr() const { |
| return getOriginExpr()->getArg(0); |
| } |
| |
| const BlockDataRegion *BlockCall::getBlockRegion() const { |
| const Expr *Callee = getOriginExpr()->getCallee(); |
| const MemRegion *DataReg = getSVal(Callee).getAsRegion(); |
| |
| return dyn_cast_or_null<BlockDataRegion>(DataReg); |
| } |
| |
| ArrayRef<ParmVarDecl*> BlockCall::parameters() const { |
| const BlockDecl *D = getDecl(); |
| if (!D) |
| return None; |
| return D->parameters(); |
| } |
| |
| void BlockCall::getExtraInvalidatedValues(ValueList &Values, |
| RegionAndSymbolInvalidationTraits *ETraits) const { |
| // FIXME: This also needs to invalidate captured globals. |
| if (const MemRegion *R = getBlockRegion()) |
| Values.push_back(loc::MemRegionVal(R)); |
| } |
| |
| void BlockCall::getInitialStackFrameContents(const StackFrameContext *CalleeCtx, |
| BindingsTy &Bindings) const { |
| SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); |
| ArrayRef<ParmVarDecl*> Params; |
| if (isConversionFromLambda()) { |
| auto *LambdaOperatorDecl = cast<CXXMethodDecl>(CalleeCtx->getDecl()); |
| Params = LambdaOperatorDecl->parameters(); |
| |
| // For blocks converted from a C++ lambda, the callee declaration is the |
| // operator() method on the lambda so we bind "this" to |
| // the lambda captured by the block. |
| const VarRegion *CapturedLambdaRegion = getRegionStoringCapturedLambda(); |
| SVal ThisVal = loc::MemRegionVal(CapturedLambdaRegion); |
| Loc ThisLoc = SVB.getCXXThis(LambdaOperatorDecl, CalleeCtx); |
| Bindings.push_back(std::make_pair(ThisLoc, ThisVal)); |
| } else { |
| Params = cast<BlockDecl>(CalleeCtx->getDecl())->parameters(); |
| } |
| |
| addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this, |
| Params); |
| } |
| |
| SVal CXXConstructorCall::getCXXThisVal() const { |
| if (Data) |
| return loc::MemRegionVal(static_cast<const MemRegion *>(Data)); |
| return UnknownVal(); |
| } |
| |
| void CXXConstructorCall::getExtraInvalidatedValues(ValueList &Values, |
| RegionAndSymbolInvalidationTraits *ETraits) const { |
| if (Data) { |
| loc::MemRegionVal MV(static_cast<const MemRegion *>(Data)); |
| if (SymbolRef Sym = MV.getAsSymbol(true)) |
| ETraits->setTrait(Sym, |
| RegionAndSymbolInvalidationTraits::TK_SuppressEscape); |
| Values.push_back(MV); |
| } |
| } |
| |
| void CXXConstructorCall::getInitialStackFrameContents( |
| const StackFrameContext *CalleeCtx, |
| BindingsTy &Bindings) const { |
| AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings); |
| |
| SVal ThisVal = getCXXThisVal(); |
| if (!ThisVal.isUnknown()) { |
| SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); |
| const auto *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl()); |
| Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx); |
| Bindings.push_back(std::make_pair(ThisLoc, ThisVal)); |
| } |
| } |
| |
| SVal CXXDestructorCall::getCXXThisVal() const { |
| if (Data) |
| return loc::MemRegionVal(DtorDataTy::getFromOpaqueValue(Data).getPointer()); |
| return UnknownVal(); |
| } |
| |
| RuntimeDefinition CXXDestructorCall::getRuntimeDefinition() const { |
| // Base destructors are always called non-virtually. |
| // Skip CXXInstanceCall's devirtualization logic in this case. |
| if (isBaseDestructor()) |
| return AnyFunctionCall::getRuntimeDefinition(); |
| |
| return CXXInstanceCall::getRuntimeDefinition(); |
| } |
| |
| ArrayRef<ParmVarDecl*> ObjCMethodCall::parameters() const { |
| const ObjCMethodDecl *D = getDecl(); |
| if (!D) |
| return None; |
| return D->parameters(); |
| } |
| |
| void ObjCMethodCall::getExtraInvalidatedValues( |
| ValueList &Values, RegionAndSymbolInvalidationTraits *ETraits) const { |
| |
| // If the method call is a setter for property known to be backed by |
| // an instance variable, don't invalidate the entire receiver, just |
| // the storage for that instance variable. |
| if (const ObjCPropertyDecl *PropDecl = getAccessedProperty()) { |
| if (const ObjCIvarDecl *PropIvar = PropDecl->getPropertyIvarDecl()) { |
| SVal IvarLVal = getState()->getLValue(PropIvar, getReceiverSVal()); |
| if (const MemRegion *IvarRegion = IvarLVal.getAsRegion()) { |
| ETraits->setTrait( |
| IvarRegion, |
| RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion); |
| ETraits->setTrait( |
| IvarRegion, |
| RegionAndSymbolInvalidationTraits::TK_SuppressEscape); |
| Values.push_back(IvarLVal); |
| } |
| return; |
| } |
| } |
| |
| Values.push_back(getReceiverSVal()); |
| } |
| |
| SVal ObjCMethodCall::getSelfSVal() const { |
| const LocationContext *LCtx = getLocationContext(); |
| const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl(); |
| if (!SelfDecl) |
| return SVal(); |
| return getState()->getSVal(getState()->getRegion(SelfDecl, LCtx)); |
| } |
| |
| SVal ObjCMethodCall::getReceiverSVal() const { |
| // FIXME: Is this the best way to handle class receivers? |
| if (!isInstanceMessage()) |
| return UnknownVal(); |
| |
| if (const Expr *RecE = getOriginExpr()->getInstanceReceiver()) |
| return getSVal(RecE); |
| |
| // An instance message with no expression means we are sending to super. |
| // In this case the object reference is the same as 'self'. |
| assert(getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance); |
| SVal SelfVal = getSelfSVal(); |
| assert(SelfVal.isValid() && "Calling super but not in ObjC method"); |
| return SelfVal; |
| } |
| |
| bool ObjCMethodCall::isReceiverSelfOrSuper() const { |
| if (getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance || |
| getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperClass) |
| return true; |
| |
| if (!isInstanceMessage()) |
| return false; |
| |
| SVal RecVal = getSVal(getOriginExpr()->getInstanceReceiver()); |
| |
| return (RecVal == getSelfSVal()); |
| } |
| |
| SourceRange ObjCMethodCall::getSourceRange() const { |
| switch (getMessageKind()) { |
| case OCM_Message: |
| return getOriginExpr()->getSourceRange(); |
| case OCM_PropertyAccess: |
| case OCM_Subscript: |
| return getContainingPseudoObjectExpr()->getSourceRange(); |
| } |
| llvm_unreachable("unknown message kind"); |
| } |
| |
| using ObjCMessageDataTy = llvm::PointerIntPair<const PseudoObjectExpr *, 2>; |
| |
| const PseudoObjectExpr *ObjCMethodCall::getContainingPseudoObjectExpr() const { |
| assert(Data && "Lazy lookup not yet performed."); |
| assert(getMessageKind() != OCM_Message && "Explicit message send."); |
| return ObjCMessageDataTy::getFromOpaqueValue(Data).getPointer(); |
| } |
| |
| static const Expr * |
| getSyntacticFromForPseudoObjectExpr(const PseudoObjectExpr *POE) { |
| const Expr *Syntactic = POE->getSyntacticForm(); |
| |
| // This handles the funny case of assigning to the result of a getter. |
| // This can happen if the getter returns a non-const reference. |
| if (const auto *BO = dyn_cast<BinaryOperator>(Syntactic)) |
| Syntactic = BO->getLHS(); |
| |
| return Syntactic; |
| } |
| |
| ObjCMessageKind ObjCMethodCall::getMessageKind() const { |
| if (!Data) { |
| // Find the parent, ignoring implicit casts. |
| const ParentMap &PM = getLocationContext()->getParentMap(); |
| const Stmt *S = PM.getParentIgnoreParenCasts(getOriginExpr()); |
| |
| // Check if parent is a PseudoObjectExpr. |
| if (const auto *POE = dyn_cast_or_null<PseudoObjectExpr>(S)) { |
| const Expr *Syntactic = getSyntacticFromForPseudoObjectExpr(POE); |
| |
| ObjCMessageKind K; |
| switch (Syntactic->getStmtClass()) { |
| case Stmt::ObjCPropertyRefExprClass: |
| K = OCM_PropertyAccess; |
| break; |
| case Stmt::ObjCSubscriptRefExprClass: |
| K = OCM_Subscript; |
| break; |
| default: |
| // FIXME: Can this ever happen? |
| K = OCM_Message; |
| break; |
| } |
| |
| if (K != OCM_Message) { |
| const_cast<ObjCMethodCall *>(this)->Data |
| = ObjCMessageDataTy(POE, K).getOpaqueValue(); |
| assert(getMessageKind() == K); |
| return K; |
| } |
| } |
| |
| const_cast<ObjCMethodCall *>(this)->Data |
| = ObjCMessageDataTy(nullptr, 1).getOpaqueValue(); |
| assert(getMessageKind() == OCM_Message); |
| return OCM_Message; |
| } |
| |
| ObjCMessageDataTy Info = ObjCMessageDataTy::getFromOpaqueValue(Data); |
| if (!Info.getPointer()) |
| return OCM_Message; |
| return static_cast<ObjCMessageKind>(Info.getInt()); |
| } |
| |
| const ObjCPropertyDecl *ObjCMethodCall::getAccessedProperty() const { |
| // Look for properties accessed with property syntax (foo.bar = ...) |
| if ( getMessageKind() == OCM_PropertyAccess) { |
| const PseudoObjectExpr *POE = getContainingPseudoObjectExpr(); |
| assert(POE && "Property access without PseudoObjectExpr?"); |
| |
| const Expr *Syntactic = getSyntacticFromForPseudoObjectExpr(POE); |
| auto *RefExpr = cast<ObjCPropertyRefExpr>(Syntactic); |
| |
| if (RefExpr->isExplicitProperty()) |
| return RefExpr->getExplicitProperty(); |
| } |
| |
| // Look for properties accessed with method syntax ([foo setBar:...]). |
| const ObjCMethodDecl *MD = getDecl(); |
| if (!MD || !MD->isPropertyAccessor()) |
| return nullptr; |
| |
| // Note: This is potentially quite slow. |
| return MD->findPropertyDecl(); |
| } |
| |
| bool ObjCMethodCall::canBeOverridenInSubclass(ObjCInterfaceDecl *IDecl, |
| Selector Sel) const { |
| assert(IDecl); |
| AnalysisManager &AMgr = |
| getState()->getStateManager().getOwningEngine().getAnalysisManager(); |
| // If the class interface is declared inside the main file, assume it is not |
| // subcassed. |
| // TODO: It could actually be subclassed if the subclass is private as well. |
| // This is probably very rare. |
| SourceLocation InterfLoc = IDecl->getEndOfDefinitionLoc(); |
| if (InterfLoc.isValid() && AMgr.isInCodeFile(InterfLoc)) |
| return false; |
| |
| // Assume that property accessors are not overridden. |
| if (getMessageKind() == OCM_PropertyAccess) |
| return false; |
| |
| // We assume that if the method is public (declared outside of main file) or |
| // has a parent which publicly declares the method, the method could be |
| // overridden in a subclass. |
| |
| // Find the first declaration in the class hierarchy that declares |
| // the selector. |
| ObjCMethodDecl *D = nullptr; |
| while (true) { |
| D = IDecl->lookupMethod(Sel, true); |
| |
| // Cannot find a public definition. |
| if (!D) |
| return false; |
| |
| // If outside the main file, |
| if (D->getLocation().isValid() && !AMgr.isInCodeFile(D->getLocation())) |
| return true; |
| |
| if (D->isOverriding()) { |
| // Search in the superclass on the next iteration. |
| IDecl = D->getClassInterface(); |
| if (!IDecl) |
| return false; |
| |
| IDecl = IDecl->getSuperClass(); |
| if (!IDecl) |
| return false; |
| |
| continue; |
| } |
| |
| return false; |
| }; |
| |
| llvm_unreachable("The while loop should always terminate."); |
| } |
| |
| static const ObjCMethodDecl *findDefiningRedecl(const ObjCMethodDecl *MD) { |
| if (!MD) |
| return MD; |
| |
| // Find the redeclaration that defines the method. |
| if (!MD->hasBody()) { |
| for (auto I : MD->redecls()) |
| if (I->hasBody()) |
| MD = cast<ObjCMethodDecl>(I); |
| } |
| return MD; |
| } |
| |
| static bool isCallToSelfClass(const ObjCMessageExpr *ME) { |
| const Expr* InstRec = ME->getInstanceReceiver(); |
| if (!InstRec) |
| return false; |
| const auto *InstRecIg = dyn_cast<DeclRefExpr>(InstRec->IgnoreParenImpCasts()); |
| |
| // Check that receiver is called 'self'. |
| if (!InstRecIg || !InstRecIg->getFoundDecl() || |
| !InstRecIg->getFoundDecl()->getName().equals("self")) |
| return false; |
| |
| // Check that the method name is 'class'. |
| if (ME->getSelector().getNumArgs() != 0 || |
| !ME->getSelector().getNameForSlot(0).equals("class")) |
| return false; |
| |
| return true; |
| } |
| |
| RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const { |
| const ObjCMessageExpr *E = getOriginExpr(); |
| assert(E); |
| Selector Sel = E->getSelector(); |
| |
| if (E->isInstanceMessage()) { |
| // Find the receiver type. |
| const ObjCObjectPointerType *ReceiverT = nullptr; |
| bool CanBeSubClassed = false; |
| QualType SupersType = E->getSuperType(); |
| const MemRegion *Receiver = nullptr; |
| |
| if (!SupersType.isNull()) { |
| // The receiver is guaranteed to be 'super' in this case. |
| // Super always means the type of immediate predecessor to the method |
| // where the call occurs. |
| ReceiverT = cast<ObjCObjectPointerType>(SupersType); |
| } else { |
| Receiver = getReceiverSVal().getAsRegion(); |
| if (!Receiver) |
| return {}; |
| |
| DynamicTypeInfo DTI = getDynamicTypeInfo(getState(), Receiver); |
| if (!DTI.isValid()) { |
| assert(isa<AllocaRegion>(Receiver) && |
| "Unhandled untyped region class!"); |
| return {}; |
| } |
| |
| QualType DynType = DTI.getType(); |
| CanBeSubClassed = DTI.canBeASubClass(); |
| ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType.getCanonicalType()); |
| |
| if (ReceiverT && CanBeSubClassed) |
| if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) |
| if (!canBeOverridenInSubclass(IDecl, Sel)) |
| CanBeSubClassed = false; |
| } |
| |
| // Handle special cases of '[self classMethod]' and |
| // '[[self class] classMethod]', which are treated by the compiler as |
| // instance (not class) messages. We will statically dispatch to those. |
| if (auto *PT = dyn_cast_or_null<ObjCObjectPointerType>(ReceiverT)) { |
| // For [self classMethod], return the compiler visible declaration. |
| if (PT->getObjectType()->isObjCClass() && |
| Receiver == getSelfSVal().getAsRegion()) |
| return RuntimeDefinition(findDefiningRedecl(E->getMethodDecl())); |
| |
| // Similarly, handle [[self class] classMethod]. |
| // TODO: We are currently doing a syntactic match for this pattern with is |
| // limiting as the test cases in Analysis/inlining/InlineObjCClassMethod.m |
| // shows. A better way would be to associate the meta type with the symbol |
| // using the dynamic type info tracking and use it here. We can add a new |
| // SVal for ObjC 'Class' values that know what interface declaration they |
| // come from. Then 'self' in a class method would be filled in with |
| // something meaningful in ObjCMethodCall::getReceiverSVal() and we could |
| // do proper dynamic dispatch for class methods just like we do for |
| // instance methods now. |
| if (E->getInstanceReceiver()) |
| if (const auto *M = dyn_cast<ObjCMessageExpr>(E->getInstanceReceiver())) |
| if (isCallToSelfClass(M)) |
| return RuntimeDefinition(findDefiningRedecl(E->getMethodDecl())); |
| } |
| |
| // Lookup the instance method implementation. |
| if (ReceiverT) |
| if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) { |
| // Repeatedly calling lookupPrivateMethod() is expensive, especially |
| // when in many cases it returns null. We cache the results so |
| // that repeated queries on the same ObjCIntefaceDecl and Selector |
| // don't incur the same cost. On some test cases, we can see the |
| // same query being issued thousands of times. |
| // |
| // NOTE: This cache is essentially a "global" variable, but it |
| // only gets lazily created when we get here. The value of the |
| // cache probably comes from it being global across ExprEngines, |
| // where the same queries may get issued. If we are worried about |
| // concurrency, or possibly loading/unloading ASTs, etc., we may |
| // need to revisit this someday. In terms of memory, this table |
| // stays around until clang quits, which also may be bad if we |
| // need to release memory. |
| using PrivateMethodKey = std::pair<const ObjCInterfaceDecl *, Selector>; |
| using PrivateMethodCache = |
| llvm::DenseMap<PrivateMethodKey, Optional<const ObjCMethodDecl *>>; |
| |
| static PrivateMethodCache PMC; |
| Optional<const ObjCMethodDecl *> &Val = PMC[std::make_pair(IDecl, Sel)]; |
| |
| // Query lookupPrivateMethod() if the cache does not hit. |
| if (!Val.hasValue()) { |
| Val = IDecl->lookupPrivateMethod(Sel); |
| |
| // If the method is a property accessor, we should try to "inline" it |
| // even if we don't actually have an implementation. |
| if (!*Val) |
| if (const ObjCMethodDecl *CompileTimeMD = E->getMethodDecl()) |
| if (CompileTimeMD->isPropertyAccessor()) { |
| if (!CompileTimeMD->getSelfDecl() && |
| isa<ObjCCategoryDecl>(CompileTimeMD->getDeclContext())) { |
| // If the method is an accessor in a category, and it doesn't |
| // have a self declaration, first |
| // try to find the method in a class extension. This |
| // works around a bug in Sema where multiple accessors |
| // are synthesized for properties in class |
| // extensions that are redeclared in a category and the |
| // the implicit parameters are not filled in for |
| // the method on the category. |
| // This ensures we find the accessor in the extension, which |
| // has the implicit parameters filled in. |
| auto *ID = CompileTimeMD->getClassInterface(); |
| for (auto *CatDecl : ID->visible_extensions()) { |
| Val = CatDecl->getMethod(Sel, |
| CompileTimeMD->isInstanceMethod()); |
| if (*Val) |
| break; |
| } |
| } |
| if (!*Val) |
| Val = IDecl->lookupInstanceMethod(Sel); |
| } |
| } |
| |
| const ObjCMethodDecl *MD = Val.getValue(); |
| if (CanBeSubClassed) |
| return RuntimeDefinition(MD, Receiver); |
| else |
| return RuntimeDefinition(MD, nullptr); |
| } |
| } else { |
| // This is a class method. |
| // If we have type info for the receiver class, we are calling via |
| // class name. |
| if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) { |
| // Find/Return the method implementation. |
| return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel)); |
| } |
| } |
| |
| return {}; |
| } |
| |
| bool ObjCMethodCall::argumentsMayEscape() const { |
| if (isInSystemHeader() && !isInstanceMessage()) { |
| Selector Sel = getSelector(); |
| if (Sel.getNumArgs() == 1 && |
| Sel.getIdentifierInfoForSlot(0)->isStr("valueWithPointer")) |
| return true; |
| } |
| |
| return CallEvent::argumentsMayEscape(); |
| } |
| |
| void ObjCMethodCall::getInitialStackFrameContents( |
| const StackFrameContext *CalleeCtx, |
| BindingsTy &Bindings) const { |
| const auto *D = cast<ObjCMethodDecl>(CalleeCtx->getDecl()); |
| SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); |
| addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this, |
| D->parameters()); |
| |
| SVal SelfVal = getReceiverSVal(); |
| if (!SelfVal.isUnknown()) { |
| const VarDecl *SelfD = CalleeCtx->getAnalysisDeclContext()->getSelfDecl(); |
| MemRegionManager &MRMgr = SVB.getRegionManager(); |
| Loc SelfLoc = SVB.makeLoc(MRMgr.getVarRegion(SelfD, CalleeCtx)); |
| Bindings.push_back(std::make_pair(SelfLoc, SelfVal)); |
| } |
| } |
| |
| CallEventRef<> |
| CallEventManager::getSimpleCall(const CallExpr *CE, ProgramStateRef State, |
| const LocationContext *LCtx) { |
| if (const auto *MCE = dyn_cast<CXXMemberCallExpr>(CE)) |
| return create<CXXMemberCall>(MCE, State, LCtx); |
| |
| if (const auto *OpCE = dyn_cast<CXXOperatorCallExpr>(CE)) { |
| const FunctionDecl *DirectCallee = OpCE->getDirectCallee(); |
| if (const auto *MD = dyn_cast<CXXMethodDecl>(DirectCallee)) |
| if (MD->isInstance()) |
| return create<CXXMemberOperatorCall>(OpCE, State, LCtx); |
| |
| } else if (CE->getCallee()->getType()->isBlockPointerType()) { |
| return create<BlockCall>(CE, State, LCtx); |
| } |
| |
| // Otherwise, it's a normal function call, static member function call, or |
| // something we can't reason about. |
| return create<SimpleFunctionCall>(CE, State, LCtx); |
| } |
| |
| CallEventRef<> |
| CallEventManager::getCaller(const StackFrameContext *CalleeCtx, |
| ProgramStateRef State) { |
| const LocationContext *ParentCtx = CalleeCtx->getParent(); |
| const LocationContext *CallerCtx = ParentCtx->getStackFrame(); |
| assert(CallerCtx && "This should not be used for top-level stack frames"); |
| |
| const Stmt *CallSite = CalleeCtx->getCallSite(); |
| |
| if (CallSite) { |
| if (CallEventRef<> Out = getCall(CallSite, State, CallerCtx)) |
| return Out; |
| |
| // All other cases are handled by getCall. |
| assert(isa<CXXConstructExpr>(CallSite) && |
| "This is not an inlineable statement"); |
| |
| SValBuilder &SVB = State->getStateManager().getSValBuilder(); |
| const auto *Ctor = cast<CXXMethodDecl>(CalleeCtx->getDecl()); |
| Loc ThisPtr = SVB.getCXXThis(Ctor, CalleeCtx); |
| SVal ThisVal = State->getSVal(ThisPtr); |
| |
| return getCXXConstructorCall(cast<CXXConstructExpr>(CallSite), |
| ThisVal.getAsRegion(), State, CallerCtx); |
| } |
| |
| // Fall back to the CFG. The only thing we haven't handled yet is |
| // destructors, though this could change in the future. |
| const CFGBlock *B = CalleeCtx->getCallSiteBlock(); |
| CFGElement E = (*B)[CalleeCtx->getIndex()]; |
| assert((E.getAs<CFGImplicitDtor>() || E.getAs<CFGTemporaryDtor>()) && |
| "All other CFG elements should have exprs"); |
| |
| SValBuilder &SVB = State->getStateManager().getSValBuilder(); |
| const auto *Dtor = cast<CXXDestructorDecl>(CalleeCtx->getDecl()); |
| Loc ThisPtr = SVB.getCXXThis(Dtor, CalleeCtx); |
| SVal ThisVal = State->getSVal(ThisPtr); |
| |
| const Stmt *Trigger; |
| if (Optional<CFGAutomaticObjDtor> AutoDtor = E.getAs<CFGAutomaticObjDtor>()) |
| Trigger = AutoDtor->getTriggerStmt(); |
| else if (Optional<CFGDeleteDtor> DeleteDtor = E.getAs<CFGDeleteDtor>()) |
| Trigger = DeleteDtor->getDeleteExpr(); |
| else |
| Trigger = Dtor->getBody(); |
| |
| return getCXXDestructorCall(Dtor, Trigger, ThisVal.getAsRegion(), |
| E.getAs<CFGBaseDtor>().hasValue(), State, |
| CallerCtx); |
| } |
| |
| CallEventRef<> CallEventManager::getCall(const Stmt *S, ProgramStateRef State, |
| const LocationContext *LC) { |
| if (const auto *CE = dyn_cast<CallExpr>(S)) { |
| return getSimpleCall(CE, State, LC); |
| } else if (const auto *NE = dyn_cast<CXXNewExpr>(S)) { |
| return getCXXAllocatorCall(NE, State, LC); |
| } else if (const auto *ME = dyn_cast<ObjCMessageExpr>(S)) { |
| return getObjCMethodCall(ME, State, LC); |
| } else { |
| return nullptr; |
| } |
| } |