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78 lines
2.3 KiB
C++
78 lines
2.3 KiB
C++
//== ReturnUndefChecker.cpp -------------------------------------*- C++ -*--==//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines ReturnUndefChecker, which is a path-sensitive
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// check which looks for undefined or garbage values being returned to the
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// caller.
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//
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//===----------------------------------------------------------------------===//
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#include "ClangSACheckers.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 "clang/StaticAnalyzer/Core/BugReporter/BugType.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 ReturnUndefChecker :
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public Checker< check::PreStmt<ReturnStmt> > {
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mutable OwningPtr<BuiltinBug> BT;
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public:
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void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const;
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};
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}
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void ReturnUndefChecker::checkPreStmt(const ReturnStmt *RS,
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CheckerContext &C) const {
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const Expr *RetE = RS->getRetValue();
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if (!RetE)
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return;
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if (!C.getState()->getSVal(RetE, C.getLocationContext()).isUndef())
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return;
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// "return;" is modeled to evaluate to an UndefinedValue. Allow UndefinedValue
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// to be returned in functions returning void to support the following pattern:
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// void foo() {
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// return;
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// }
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// void test() {
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// return foo();
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// }
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const StackFrameContext *SFC = C.getStackFrame();
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QualType RT = CallEvent::getDeclaredResultType(SFC->getDecl());
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if (!RT.isNull() && RT->isSpecificBuiltinType(BuiltinType::Void))
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return;
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ExplodedNode *N = C.generateSink();
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if (!N)
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return;
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if (!BT)
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BT.reset(new BuiltinBug("Garbage return value",
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"Undefined or garbage value returned to caller"));
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BugReport *report =
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new BugReport(*BT, BT->getDescription(), N);
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report->addRange(RetE->getSourceRange());
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bugreporter::trackNullOrUndefValue(N, RetE, *report);
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C.emitReport(report);
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}
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void ento::registerReturnUndefChecker(CheckerManager &mgr) {
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mgr.registerChecker<ReturnUndefChecker>();
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}
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