forked from OSchip/llvm-project
87 lines
2.8 KiB
C++
87 lines
2.8 KiB
C++
//=== CastSizeChecker.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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// CastSizeChecker checks when casting a malloc'ed symbolic region to type T,
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// whether the size of the symbolic region is a multiple of the size of T.
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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/CheckerContext.h"
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#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
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#include "clang/AST/CharUnits.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 CastSizeChecker : public Checker< check::PreStmt<CastExpr> > {
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mutable llvm::OwningPtr<BuiltinBug> BT;
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public:
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void checkPreStmt(const CastExpr *CE, CheckerContext &C) const;
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};
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}
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void CastSizeChecker::checkPreStmt(const CastExpr *CE,CheckerContext &C) const {
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const Expr *E = CE->getSubExpr();
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ASTContext &Ctx = C.getASTContext();
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QualType ToTy = Ctx.getCanonicalType(CE->getType());
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const PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
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if (!ToPTy)
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return;
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QualType ToPointeeTy = ToPTy->getPointeeType();
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// Only perform the check if 'ToPointeeTy' is a complete type.
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if (ToPointeeTy->isIncompleteType())
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return;
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const GRState *state = C.getState();
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const MemRegion *R = state->getSVal(E).getAsRegion();
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if (R == 0)
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return;
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const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R);
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if (SR == 0)
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return;
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SValBuilder &svalBuilder = C.getSValBuilder();
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SVal extent = SR->getExtent(svalBuilder);
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const llvm::APSInt *extentInt = svalBuilder.getKnownValue(state, extent);
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if (!extentInt)
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return;
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CharUnits regionSize = CharUnits::fromQuantity(extentInt->getSExtValue());
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CharUnits typeSize = C.getASTContext().getTypeSizeInChars(ToPointeeTy);
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// Ignore void, and a few other un-sizeable types.
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if (typeSize.isZero())
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return;
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if (regionSize % typeSize != 0) {
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if (ExplodedNode *errorNode = C.generateSink()) {
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if (!BT)
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BT.reset(new BuiltinBug("Cast region with wrong size.",
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"Cast a region whose size is not a multiple of the"
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" destination type size."));
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RangedBugReport *R = new RangedBugReport(*BT, BT->getDescription(),
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errorNode);
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R->addRange(CE->getSourceRange());
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C.EmitReport(R);
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}
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}
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}
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void ento::registerCastSizeChecker(CheckerManager &mgr) {
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mgr.registerChecker<CastSizeChecker>();
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}
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