forked from OSchip/llvm-project
126 lines
4.0 KiB
C++
126 lines
4.0 KiB
C++
//== ReturnStackAddressChecker.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 ReturnStackAddressChecker, which is a path-sensitive
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// check which looks for the addresses of stack variables being returned to
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// callers.
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//
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//===----------------------------------------------------------------------===//
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#include "GRExprEngineInternalChecks.h"
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#include "clang/Checker/PathSensitive/GRExprEngine.h"
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#include "clang/Checker/BugReporter/BugReporter.h"
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#include "clang/Checker/PathSensitive/CheckerVisitor.h"
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#include "clang/Basic/SourceManager.h"
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#include "llvm/ADT/SmallString.h"
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using namespace clang;
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namespace {
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class ReturnStackAddressChecker :
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public CheckerVisitor<ReturnStackAddressChecker> {
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BuiltinBug *BT;
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public:
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ReturnStackAddressChecker() : BT(0) {}
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static void *getTag();
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void PreVisitReturnStmt(CheckerContext &C, const ReturnStmt *RS);
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private:
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void EmitStackError(CheckerContext &C, const MemRegion *R, const Expr *RetE);
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};
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}
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void clang::RegisterReturnStackAddressChecker(GRExprEngine &Eng) {
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Eng.registerCheck(new ReturnStackAddressChecker());
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}
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void *ReturnStackAddressChecker::getTag() {
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static int x = 0; return &x;
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}
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void ReturnStackAddressChecker::EmitStackError(CheckerContext &C,
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const MemRegion *R,
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const Expr *RetE) {
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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 = new BuiltinBug("Return of address to stack-allocated memory");
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// Generate a report for this bug.
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llvm::SmallString<512> buf;
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llvm::raw_svector_ostream os(buf);
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SourceRange range;
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// Get the base region, stripping away fields and elements.
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R = R->getBaseRegion();
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// Check if the region is a compound literal.
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if (const CompoundLiteralRegion* CR = dyn_cast<CompoundLiteralRegion>(R)) {
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const CompoundLiteralExpr* CL = CR->getLiteralExpr();
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os << "Address of stack memory associated with a compound literal "
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"declared on line "
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<< C.getSourceManager().getInstantiationLineNumber(CL->getLocStart())
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<< " returned to caller";
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range = CL->getSourceRange();
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}
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else if (const AllocaRegion* AR = dyn_cast<AllocaRegion>(R)) {
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const Expr* ARE = AR->getExpr();
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SourceLocation L = ARE->getLocStart();
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range = ARE->getSourceRange();
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os << "Address of stack memory allocated by call to alloca() on line "
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<< C.getSourceManager().getInstantiationLineNumber(L)
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<< " returned to caller";
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}
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else if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
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const BlockDecl *BD = BR->getCodeRegion()->getDecl();
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SourceLocation L = BD->getLocStart();
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range = BD->getSourceRange();
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os << "Address of stack-allocated block declared on line "
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<< C.getSourceManager().getInstantiationLineNumber(L)
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<< " returned to caller";
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}
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else if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
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os << "Address of stack memory associated with local variable '"
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<< VR->getString() << "' returned";
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range = VR->getDecl()->getSourceRange();
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}
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else {
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assert(false && "Invalid region in ReturnStackAddressChecker.");
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return;
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}
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RangedBugReport *report = new RangedBugReport(*BT, os.str(), N);
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report->addRange(RetE->getSourceRange());
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if (range.isValid())
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report->addRange(range);
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C.EmitReport(report);
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}
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void ReturnStackAddressChecker::PreVisitReturnStmt(CheckerContext &C,
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const ReturnStmt *RS) {
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const Expr *RetE = RS->getRetValue();
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if (!RetE)
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return;
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SVal V = C.getState()->getSVal(RetE);
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const MemRegion *R = V.getAsRegion();
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if (!R || !R->hasStackStorage())
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return;
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if (R->hasStackStorage()) {
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EmitStackError(C, R, RetE);
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return;
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}
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}
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