764 lines
27 KiB
C++
764 lines
27 KiB
C++
//===--- CallAndMessageChecker.cpp ------------------------------*- C++ -*--==//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This defines CallAndMessageChecker, a builtin checker that checks for various
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// errors of call and objc message expressions.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/AST/ExprCXX.h"
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#include "clang/AST/ParentMap.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
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#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
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#include "clang/StaticAnalyzer/Core/Checker.h"
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#include "clang/StaticAnalyzer/Core/CheckerManager.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace clang;
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using namespace ento;
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namespace {
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class CallAndMessageChecker
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: public Checker<check::PreObjCMessage, check::ObjCMessageNil,
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check::PreCall> {
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mutable std::unique_ptr<BugType> BT_call_null;
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mutable std::unique_ptr<BugType> BT_call_undef;
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mutable std::unique_ptr<BugType> BT_cxx_call_null;
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mutable std::unique_ptr<BugType> BT_cxx_call_undef;
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mutable std::unique_ptr<BugType> BT_call_arg;
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mutable std::unique_ptr<BugType> BT_cxx_delete_undef;
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mutable std::unique_ptr<BugType> BT_msg_undef;
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mutable std::unique_ptr<BugType> BT_objc_prop_undef;
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mutable std::unique_ptr<BugType> BT_objc_subscript_undef;
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mutable std::unique_ptr<BugType> BT_msg_arg;
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mutable std::unique_ptr<BugType> BT_msg_ret;
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mutable std::unique_ptr<BugType> BT_call_few_args;
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public:
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// These correspond with the checker options. Looking at other checkers such
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// as MallocChecker and CStringChecker, this is similar as to how they pull
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// off having a modeling class, but emitting diagnostics under a smaller
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// checker's name that can be safely disabled without disturbing the
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// underlaying modeling engine.
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// The reason behind having *checker options* rather then actual *checkers*
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// here is that CallAndMessage is among the oldest checkers out there, and can
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// be responsible for the majority of the reports on any given project. This
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// is obviously not ideal, but changing checker name has the consequence of
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// changing the issue hashes associated with the reports, and databases
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// relying on this (CodeChecker, for instance) would suffer greatly.
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// If we ever end up making changes to the issue hash generation algorithm, or
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// the warning messages here, we should totally jump on the opportunity to
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// convert these to actual checkers.
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enum CheckKind {
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CK_FunctionPointer,
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CK_ParameterCount,
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CK_CXXThisMethodCall,
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CK_CXXDeallocationArg,
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CK_ArgInitializedness,
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CK_ArgPointeeInitializedness,
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CK_NilReceiver,
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CK_UndefReceiver,
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CK_NumCheckKinds
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};
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DefaultBool ChecksEnabled[CK_NumCheckKinds];
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// The original core.CallAndMessage checker name. This should rather be an
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// array, as seen in MallocChecker and CStringChecker.
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CheckerNameRef OriginalName;
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void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
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/// Fill in the return value that results from messaging nil based on the
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/// return type and architecture and diagnose if the return value will be
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/// garbage.
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void checkObjCMessageNil(const ObjCMethodCall &msg, CheckerContext &C) const;
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void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
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ProgramStateRef checkFunctionPointerCall(const CallExpr *CE,
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CheckerContext &C,
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ProgramStateRef State) const;
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ProgramStateRef checkCXXMethodCall(const CXXInstanceCall *CC,
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CheckerContext &C,
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ProgramStateRef State) const;
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ProgramStateRef checkParameterCount(const CallEvent &Call, CheckerContext &C,
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ProgramStateRef State) const;
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ProgramStateRef checkCXXDeallocation(const CXXDeallocatorCall *DC,
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CheckerContext &C,
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ProgramStateRef State) const;
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ProgramStateRef checkArgInitializedness(const CallEvent &Call,
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CheckerContext &C,
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ProgramStateRef State) const;
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private:
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bool PreVisitProcessArg(CheckerContext &C, SVal V, SourceRange ArgRange,
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const Expr *ArgEx, int ArgumentNumber,
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bool CheckUninitFields, const CallEvent &Call,
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std::unique_ptr<BugType> &BT,
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const ParmVarDecl *ParamDecl) const;
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static void emitBadCall(BugType *BT, CheckerContext &C, const Expr *BadE);
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void emitNilReceiverBug(CheckerContext &C, const ObjCMethodCall &msg,
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ExplodedNode *N) const;
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void HandleNilReceiver(CheckerContext &C,
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ProgramStateRef state,
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const ObjCMethodCall &msg) const;
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void LazyInit_BT(const char *desc, std::unique_ptr<BugType> &BT) const {
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if (!BT)
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BT.reset(new BuiltinBug(OriginalName, desc));
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}
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bool uninitRefOrPointer(CheckerContext &C, const SVal &V,
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SourceRange ArgRange, const Expr *ArgEx,
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std::unique_ptr<BugType> &BT,
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const ParmVarDecl *ParamDecl, const char *BD,
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int ArgumentNumber) const;
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};
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} // end anonymous namespace
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void CallAndMessageChecker::emitBadCall(BugType *BT, CheckerContext &C,
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const Expr *BadE) {
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ExplodedNode *N = C.generateErrorNode();
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if (!N)
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return;
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auto R = std::make_unique<PathSensitiveBugReport>(*BT, BT->getDescription(), N);
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if (BadE) {
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R->addRange(BadE->getSourceRange());
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if (BadE->isGLValue())
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BadE = bugreporter::getDerefExpr(BadE);
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bugreporter::trackExpressionValue(N, BadE, *R);
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}
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C.emitReport(std::move(R));
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}
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static void describeUninitializedArgumentInCall(const CallEvent &Call,
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int ArgumentNumber,
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llvm::raw_svector_ostream &Os) {
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switch (Call.getKind()) {
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case CE_ObjCMessage: {
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const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call);
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switch (Msg.getMessageKind()) {
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case OCM_Message:
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Os << (ArgumentNumber + 1) << llvm::getOrdinalSuffix(ArgumentNumber + 1)
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<< " argument in message expression is an uninitialized value";
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return;
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case OCM_PropertyAccess:
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assert(Msg.isSetter() && "Getters have no args");
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Os << "Argument for property setter is an uninitialized value";
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return;
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case OCM_Subscript:
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if (Msg.isSetter() && (ArgumentNumber == 0))
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Os << "Argument for subscript setter is an uninitialized value";
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else
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Os << "Subscript index is an uninitialized value";
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return;
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}
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llvm_unreachable("Unknown message kind.");
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}
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case CE_Block:
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Os << (ArgumentNumber + 1) << llvm::getOrdinalSuffix(ArgumentNumber + 1)
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<< " block call argument is an uninitialized value";
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return;
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default:
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Os << (ArgumentNumber + 1) << llvm::getOrdinalSuffix(ArgumentNumber + 1)
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<< " function call argument is an uninitialized value";
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return;
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}
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}
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bool CallAndMessageChecker::uninitRefOrPointer(
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CheckerContext &C, const SVal &V, SourceRange ArgRange, const Expr *ArgEx,
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std::unique_ptr<BugType> &BT, const ParmVarDecl *ParamDecl, const char *BD,
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int ArgumentNumber) const {
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// The pointee being uninitialized is a sign of code smell, not a bug, no need
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// to sink here.
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if (!ChecksEnabled[CK_ArgPointeeInitializedness])
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return false;
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// No parameter declaration available, i.e. variadic function argument.
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if(!ParamDecl)
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return false;
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// If parameter is declared as pointer to const in function declaration,
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// then check if corresponding argument in function call is
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// pointing to undefined symbol value (uninitialized memory).
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SmallString<200> Buf;
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llvm::raw_svector_ostream Os(Buf);
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if (ParamDecl->getType()->isPointerType()) {
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Os << (ArgumentNumber + 1) << llvm::getOrdinalSuffix(ArgumentNumber + 1)
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<< " function call argument is a pointer to uninitialized value";
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} else if (ParamDecl->getType()->isReferenceType()) {
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Os << (ArgumentNumber + 1) << llvm::getOrdinalSuffix(ArgumentNumber + 1)
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<< " function call argument is an uninitialized value";
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} else
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return false;
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if(!ParamDecl->getType()->getPointeeType().isConstQualified())
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return false;
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if (const MemRegion *SValMemRegion = V.getAsRegion()) {
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const ProgramStateRef State = C.getState();
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const SVal PSV = State->getSVal(SValMemRegion, C.getASTContext().CharTy);
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if (PSV.isUndef()) {
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if (ExplodedNode *N = C.generateErrorNode()) {
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LazyInit_BT(BD, BT);
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auto R = std::make_unique<PathSensitiveBugReport>(*BT, Os.str(), N);
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R->addRange(ArgRange);
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if (ArgEx)
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bugreporter::trackExpressionValue(N, ArgEx, *R);
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C.emitReport(std::move(R));
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}
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return true;
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}
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}
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return false;
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}
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namespace {
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class FindUninitializedField {
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public:
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SmallVector<const FieldDecl *, 10> FieldChain;
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private:
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StoreManager &StoreMgr;
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MemRegionManager &MrMgr;
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Store store;
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public:
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FindUninitializedField(StoreManager &storeMgr, MemRegionManager &mrMgr,
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Store s)
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: StoreMgr(storeMgr), MrMgr(mrMgr), store(s) {}
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bool Find(const TypedValueRegion *R) {
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QualType T = R->getValueType();
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if (const RecordType *RT = T->getAsStructureType()) {
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const RecordDecl *RD = RT->getDecl()->getDefinition();
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assert(RD && "Referred record has no definition");
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for (const auto *I : RD->fields()) {
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const FieldRegion *FR = MrMgr.getFieldRegion(I, R);
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FieldChain.push_back(I);
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T = I->getType();
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if (T->getAsStructureType()) {
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if (Find(FR))
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return true;
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} else {
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const SVal &V = StoreMgr.getBinding(store, loc::MemRegionVal(FR));
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if (V.isUndef())
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return true;
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}
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FieldChain.pop_back();
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}
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}
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return false;
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}
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};
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} // namespace
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bool CallAndMessageChecker::PreVisitProcessArg(CheckerContext &C,
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SVal V,
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SourceRange ArgRange,
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const Expr *ArgEx,
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int ArgumentNumber,
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bool CheckUninitFields,
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const CallEvent &Call,
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std::unique_ptr<BugType> &BT,
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const ParmVarDecl *ParamDecl
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) const {
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const char *BD = "Uninitialized argument value";
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if (uninitRefOrPointer(C, V, ArgRange, ArgEx, BT, ParamDecl, BD,
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ArgumentNumber))
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return true;
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if (V.isUndef()) {
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if (!ChecksEnabled[CK_ArgInitializedness]) {
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C.addSink();
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return true;
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}
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if (ExplodedNode *N = C.generateErrorNode()) {
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LazyInit_BT(BD, BT);
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// Generate a report for this bug.
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SmallString<200> Buf;
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llvm::raw_svector_ostream Os(Buf);
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describeUninitializedArgumentInCall(Call, ArgumentNumber, Os);
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auto R = std::make_unique<PathSensitiveBugReport>(*BT, Os.str(), N);
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R->addRange(ArgRange);
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if (ArgEx)
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bugreporter::trackExpressionValue(N, ArgEx, *R);
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C.emitReport(std::move(R));
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}
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return true;
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}
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if (!CheckUninitFields)
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return false;
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if (auto LV = V.getAs<nonloc::LazyCompoundVal>()) {
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const LazyCompoundValData *D = LV->getCVData();
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FindUninitializedField F(C.getState()->getStateManager().getStoreManager(),
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C.getSValBuilder().getRegionManager(),
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D->getStore());
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if (F.Find(D->getRegion())) {
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if (!ChecksEnabled[CK_ArgInitializedness]) {
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C.addSink();
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return true;
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}
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if (ExplodedNode *N = C.generateErrorNode()) {
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LazyInit_BT(BD, BT);
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SmallString<512> Str;
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llvm::raw_svector_ostream os(Str);
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os << "Passed-by-value struct argument contains uninitialized data";
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if (F.FieldChain.size() == 1)
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os << " (e.g., field: '" << *F.FieldChain[0] << "')";
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else {
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os << " (e.g., via the field chain: '";
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bool first = true;
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for (SmallVectorImpl<const FieldDecl *>::iterator
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DI = F.FieldChain.begin(), DE = F.FieldChain.end(); DI!=DE;++DI){
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if (first)
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first = false;
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else
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os << '.';
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os << **DI;
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}
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os << "')";
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}
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// Generate a report for this bug.
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auto R = std::make_unique<PathSensitiveBugReport>(*BT, os.str(), N);
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R->addRange(ArgRange);
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if (ArgEx)
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bugreporter::trackExpressionValue(N, ArgEx, *R);
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// FIXME: enhance track back for uninitialized value for arbitrary
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// memregions
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C.emitReport(std::move(R));
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}
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return true;
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}
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}
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return false;
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}
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ProgramStateRef CallAndMessageChecker::checkFunctionPointerCall(
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const CallExpr *CE, CheckerContext &C, ProgramStateRef State) const {
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const Expr *Callee = CE->getCallee()->IgnoreParens();
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const LocationContext *LCtx = C.getLocationContext();
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SVal L = State->getSVal(Callee, LCtx);
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if (L.isUndef()) {
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if (!ChecksEnabled[CK_FunctionPointer]) {
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C.addSink(State);
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return nullptr;
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}
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if (!BT_call_undef)
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BT_call_undef.reset(new BuiltinBug(
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OriginalName,
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"Called function pointer is an uninitialized pointer value"));
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emitBadCall(BT_call_undef.get(), C, Callee);
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return nullptr;
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}
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ProgramStateRef StNonNull, StNull;
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std::tie(StNonNull, StNull) = State->assume(L.castAs<DefinedOrUnknownSVal>());
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if (StNull && !StNonNull) {
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if (!ChecksEnabled[CK_FunctionPointer]) {
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C.addSink(StNull);
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return nullptr;
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}
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if (!BT_call_null)
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BT_call_null.reset(new BuiltinBug(
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OriginalName, "Called function pointer is null (null dereference)"));
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emitBadCall(BT_call_null.get(), C, Callee);
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return nullptr;
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}
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return StNonNull;
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}
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ProgramStateRef CallAndMessageChecker::checkParameterCount(
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const CallEvent &Call, CheckerContext &C, ProgramStateRef State) const {
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// If we have a function or block declaration, we can make sure we pass
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// enough parameters.
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unsigned Params = Call.parameters().size();
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if (Call.getNumArgs() >= Params)
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return State;
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if (!ChecksEnabled[CK_ParameterCount]) {
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C.addSink(State);
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return nullptr;
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}
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ExplodedNode *N = C.generateErrorNode();
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if (!N)
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return nullptr;
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LazyInit_BT("Function call with too few arguments", BT_call_few_args);
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SmallString<512> Str;
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llvm::raw_svector_ostream os(Str);
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if (isa<AnyFunctionCall>(Call)) {
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os << "Function ";
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} else {
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assert(isa<BlockCall>(Call));
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os << "Block ";
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}
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os << "taking " << Params << " argument" << (Params == 1 ? "" : "s")
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<< " is called with fewer (" << Call.getNumArgs() << ")";
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C.emitReport(
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std::make_unique<PathSensitiveBugReport>(*BT_call_few_args, os.str(), N));
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return nullptr;
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}
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ProgramStateRef CallAndMessageChecker::checkCXXMethodCall(
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const CXXInstanceCall *CC, CheckerContext &C, ProgramStateRef State) const {
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SVal V = CC->getCXXThisVal();
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if (V.isUndef()) {
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if (!ChecksEnabled[CK_CXXThisMethodCall]) {
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C.addSink(State);
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return nullptr;
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}
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if (!BT_cxx_call_undef)
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BT_cxx_call_undef.reset(new BuiltinBug(
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OriginalName, "Called C++ object pointer is uninitialized"));
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emitBadCall(BT_cxx_call_undef.get(), C, CC->getCXXThisExpr());
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return nullptr;
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}
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ProgramStateRef StNonNull, StNull;
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std::tie(StNonNull, StNull) = State->assume(V.castAs<DefinedOrUnknownSVal>());
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if (StNull && !StNonNull) {
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if (!ChecksEnabled[CK_CXXThisMethodCall]) {
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C.addSink(StNull);
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return nullptr;
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}
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if (!BT_cxx_call_null)
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BT_cxx_call_null.reset(
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new BuiltinBug(OriginalName, "Called C++ object pointer is null"));
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emitBadCall(BT_cxx_call_null.get(), C, CC->getCXXThisExpr());
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return nullptr;
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}
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return StNonNull;
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}
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ProgramStateRef
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CallAndMessageChecker::checkCXXDeallocation(const CXXDeallocatorCall *DC,
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CheckerContext &C,
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ProgramStateRef State) const {
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const CXXDeleteExpr *DE = DC->getOriginExpr();
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assert(DE);
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SVal Arg = C.getSVal(DE->getArgument());
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if (!Arg.isUndef())
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return State;
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if (!ChecksEnabled[CK_CXXDeallocationArg]) {
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C.addSink(State);
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return nullptr;
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}
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StringRef Desc;
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ExplodedNode *N = C.generateErrorNode();
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if (!N)
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return nullptr;
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|
if (!BT_cxx_delete_undef)
|
|
BT_cxx_delete_undef.reset(
|
|
new BuiltinBug(OriginalName, "Uninitialized argument value"));
|
|
if (DE->isArrayFormAsWritten())
|
|
Desc = "Argument to 'delete[]' is uninitialized";
|
|
else
|
|
Desc = "Argument to 'delete' is uninitialized";
|
|
BugType *BT = BT_cxx_delete_undef.get();
|
|
auto R = std::make_unique<PathSensitiveBugReport>(*BT, Desc, N);
|
|
bugreporter::trackExpressionValue(N, DE, *R);
|
|
C.emitReport(std::move(R));
|
|
return nullptr;
|
|
}
|
|
|
|
ProgramStateRef CallAndMessageChecker::checkArgInitializedness(
|
|
const CallEvent &Call, CheckerContext &C, ProgramStateRef State) const {
|
|
|
|
const Decl *D = Call.getDecl();
|
|
|
|
// Don't check for uninitialized field values in arguments if the
|
|
// caller has a body that is available and we have the chance to inline it.
|
|
// This is a hack, but is a reasonable compromise betweens sometimes warning
|
|
// and sometimes not depending on if we decide to inline a function.
|
|
const bool checkUninitFields =
|
|
!(C.getAnalysisManager().shouldInlineCall() && (D && D->getBody()));
|
|
|
|
std::unique_ptr<BugType> *BT;
|
|
if (isa<ObjCMethodCall>(Call))
|
|
BT = &BT_msg_arg;
|
|
else
|
|
BT = &BT_call_arg;
|
|
|
|
const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D);
|
|
for (unsigned i = 0, e = Call.getNumArgs(); i != e; ++i) {
|
|
const ParmVarDecl *ParamDecl = nullptr;
|
|
if (FD && i < FD->getNumParams())
|
|
ParamDecl = FD->getParamDecl(i);
|
|
if (PreVisitProcessArg(C, Call.getArgSVal(i), Call.getArgSourceRange(i),
|
|
Call.getArgExpr(i), i, checkUninitFields, Call, *BT,
|
|
ParamDecl))
|
|
return nullptr;
|
|
}
|
|
return State;
|
|
}
|
|
|
|
void CallAndMessageChecker::checkPreCall(const CallEvent &Call,
|
|
CheckerContext &C) const {
|
|
ProgramStateRef State = C.getState();
|
|
|
|
if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr()))
|
|
State = checkFunctionPointerCall(CE, C, State);
|
|
|
|
if (!State)
|
|
return;
|
|
|
|
if (Call.getDecl())
|
|
State = checkParameterCount(Call, C, State);
|
|
|
|
if (!State)
|
|
return;
|
|
|
|
if (const auto *CC = dyn_cast<CXXInstanceCall>(&Call))
|
|
State = checkCXXMethodCall(CC, C, State);
|
|
|
|
if (!State)
|
|
return;
|
|
|
|
if (const auto *DC = dyn_cast<CXXDeallocatorCall>(&Call))
|
|
State = checkCXXDeallocation(DC, C, State);
|
|
|
|
if (!State)
|
|
return;
|
|
|
|
State = checkArgInitializedness(Call, C, State);
|
|
|
|
// If we make it here, record our assumptions about the callee.
|
|
C.addTransition(State);
|
|
}
|
|
|
|
void CallAndMessageChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
|
|
CheckerContext &C) const {
|
|
SVal recVal = msg.getReceiverSVal();
|
|
if (recVal.isUndef()) {
|
|
if (!ChecksEnabled[CK_UndefReceiver]) {
|
|
C.addSink();
|
|
return;
|
|
}
|
|
if (ExplodedNode *N = C.generateErrorNode()) {
|
|
BugType *BT = nullptr;
|
|
switch (msg.getMessageKind()) {
|
|
case OCM_Message:
|
|
if (!BT_msg_undef)
|
|
BT_msg_undef.reset(new BuiltinBug(OriginalName,
|
|
"Receiver in message expression "
|
|
"is an uninitialized value"));
|
|
BT = BT_msg_undef.get();
|
|
break;
|
|
case OCM_PropertyAccess:
|
|
if (!BT_objc_prop_undef)
|
|
BT_objc_prop_undef.reset(new BuiltinBug(
|
|
OriginalName,
|
|
"Property access on an uninitialized object pointer"));
|
|
BT = BT_objc_prop_undef.get();
|
|
break;
|
|
case OCM_Subscript:
|
|
if (!BT_objc_subscript_undef)
|
|
BT_objc_subscript_undef.reset(new BuiltinBug(
|
|
OriginalName,
|
|
"Subscript access on an uninitialized object pointer"));
|
|
BT = BT_objc_subscript_undef.get();
|
|
break;
|
|
}
|
|
assert(BT && "Unknown message kind.");
|
|
|
|
auto R = std::make_unique<PathSensitiveBugReport>(*BT, BT->getDescription(), N);
|
|
const ObjCMessageExpr *ME = msg.getOriginExpr();
|
|
R->addRange(ME->getReceiverRange());
|
|
|
|
// FIXME: getTrackNullOrUndefValueVisitor can't handle "super" yet.
|
|
if (const Expr *ReceiverE = ME->getInstanceReceiver())
|
|
bugreporter::trackExpressionValue(N, ReceiverE, *R);
|
|
C.emitReport(std::move(R));
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
void CallAndMessageChecker::checkObjCMessageNil(const ObjCMethodCall &msg,
|
|
CheckerContext &C) const {
|
|
HandleNilReceiver(C, C.getState(), msg);
|
|
}
|
|
|
|
void CallAndMessageChecker::emitNilReceiverBug(CheckerContext &C,
|
|
const ObjCMethodCall &msg,
|
|
ExplodedNode *N) const {
|
|
if (!ChecksEnabled[CK_NilReceiver]) {
|
|
C.addSink();
|
|
return;
|
|
}
|
|
|
|
if (!BT_msg_ret)
|
|
BT_msg_ret.reset(new BuiltinBug(OriginalName,
|
|
"Receiver in message expression is 'nil'"));
|
|
|
|
const ObjCMessageExpr *ME = msg.getOriginExpr();
|
|
|
|
QualType ResTy = msg.getResultType();
|
|
|
|
SmallString<200> buf;
|
|
llvm::raw_svector_ostream os(buf);
|
|
os << "The receiver of message '";
|
|
ME->getSelector().print(os);
|
|
os << "' is nil";
|
|
if (ResTy->isReferenceType()) {
|
|
os << ", which results in forming a null reference";
|
|
} else {
|
|
os << " and returns a value of type '";
|
|
msg.getResultType().print(os, C.getLangOpts());
|
|
os << "' that will be garbage";
|
|
}
|
|
|
|
auto report =
|
|
std::make_unique<PathSensitiveBugReport>(*BT_msg_ret, os.str(), N);
|
|
report->addRange(ME->getReceiverRange());
|
|
// FIXME: This won't track "self" in messages to super.
|
|
if (const Expr *receiver = ME->getInstanceReceiver()) {
|
|
bugreporter::trackExpressionValue(N, receiver, *report);
|
|
}
|
|
C.emitReport(std::move(report));
|
|
}
|
|
|
|
static bool supportsNilWithFloatRet(const llvm::Triple &triple) {
|
|
return (triple.getVendor() == llvm::Triple::Apple &&
|
|
(triple.isiOS() || triple.isWatchOS() ||
|
|
!triple.isMacOSXVersionLT(10,5)));
|
|
}
|
|
|
|
void CallAndMessageChecker::HandleNilReceiver(CheckerContext &C,
|
|
ProgramStateRef state,
|
|
const ObjCMethodCall &Msg) const {
|
|
ASTContext &Ctx = C.getASTContext();
|
|
static CheckerProgramPointTag Tag(this, "NilReceiver");
|
|
|
|
// Check the return type of the message expression. A message to nil will
|
|
// return different values depending on the return type and the architecture.
|
|
QualType RetTy = Msg.getResultType();
|
|
CanQualType CanRetTy = Ctx.getCanonicalType(RetTy);
|
|
const LocationContext *LCtx = C.getLocationContext();
|
|
|
|
if (CanRetTy->isStructureOrClassType()) {
|
|
// Structure returns are safe since the compiler zeroes them out.
|
|
SVal V = C.getSValBuilder().makeZeroVal(RetTy);
|
|
C.addTransition(state->BindExpr(Msg.getOriginExpr(), LCtx, V), &Tag);
|
|
return;
|
|
}
|
|
|
|
// Other cases: check if sizeof(return type) > sizeof(void*)
|
|
if (CanRetTy != Ctx.VoidTy && C.getLocationContext()->getParentMap()
|
|
.isConsumedExpr(Msg.getOriginExpr())) {
|
|
// Compute: sizeof(void *) and sizeof(return type)
|
|
const uint64_t voidPtrSize = Ctx.getTypeSize(Ctx.VoidPtrTy);
|
|
const uint64_t returnTypeSize = Ctx.getTypeSize(CanRetTy);
|
|
|
|
if (CanRetTy.getTypePtr()->isReferenceType()||
|
|
(voidPtrSize < returnTypeSize &&
|
|
!(supportsNilWithFloatRet(Ctx.getTargetInfo().getTriple()) &&
|
|
(Ctx.FloatTy == CanRetTy ||
|
|
Ctx.DoubleTy == CanRetTy ||
|
|
Ctx.LongDoubleTy == CanRetTy ||
|
|
Ctx.LongLongTy == CanRetTy ||
|
|
Ctx.UnsignedLongLongTy == CanRetTy)))) {
|
|
if (ExplodedNode *N = C.generateErrorNode(state, &Tag))
|
|
emitNilReceiverBug(C, Msg, N);
|
|
return;
|
|
}
|
|
|
|
// Handle the safe cases where the return value is 0 if the
|
|
// receiver is nil.
|
|
//
|
|
// FIXME: For now take the conservative approach that we only
|
|
// return null values if we *know* that the receiver is nil.
|
|
// This is because we can have surprises like:
|
|
//
|
|
// ... = [[NSScreens screens] objectAtIndex:0];
|
|
//
|
|
// What can happen is that [... screens] could return nil, but
|
|
// it most likely isn't nil. We should assume the semantics
|
|
// of this case unless we have *a lot* more knowledge.
|
|
//
|
|
SVal V = C.getSValBuilder().makeZeroVal(RetTy);
|
|
C.addTransition(state->BindExpr(Msg.getOriginExpr(), LCtx, V), &Tag);
|
|
return;
|
|
}
|
|
|
|
C.addTransition(state);
|
|
}
|
|
|
|
void ento::registerCallAndMessageModeling(CheckerManager &mgr) {
|
|
mgr.registerChecker<CallAndMessageChecker>();
|
|
}
|
|
|
|
bool ento::shouldRegisterCallAndMessageModeling(const CheckerManager &mgr) {
|
|
return true;
|
|
}
|
|
|
|
void ento::registerCallAndMessageChecker(CheckerManager &mgr) {
|
|
CallAndMessageChecker *checker = mgr.getChecker<CallAndMessageChecker>();
|
|
|
|
checker->OriginalName = mgr.getCurrentCheckerName();
|
|
|
|
#define QUERY_CHECKER_OPTION(OPTION) \
|
|
checker->ChecksEnabled[CallAndMessageChecker::CK_##OPTION] = \
|
|
mgr.getAnalyzerOptions().getCheckerBooleanOption( \
|
|
mgr.getCurrentCheckerName(), #OPTION);
|
|
|
|
QUERY_CHECKER_OPTION(FunctionPointer)
|
|
QUERY_CHECKER_OPTION(ParameterCount)
|
|
QUERY_CHECKER_OPTION(CXXThisMethodCall)
|
|
QUERY_CHECKER_OPTION(CXXDeallocationArg)
|
|
QUERY_CHECKER_OPTION(ArgInitializedness)
|
|
QUERY_CHECKER_OPTION(ArgPointeeInitializedness)
|
|
QUERY_CHECKER_OPTION(NilReceiver)
|
|
QUERY_CHECKER_OPTION(UndefReceiver)
|
|
}
|
|
|
|
bool ento::shouldRegisterCallAndMessageChecker(const CheckerManager &mgr) {
|
|
return true;
|
|
}
|