along the way. Important changes: 1) To generate a sink node, use GenerateSink(); GenerateNode() is for generating regular transitions. This makes the API clearer and also allows us to use the 'bool' option to GenerateNode() for a different purpose. 2) GenerateNode() now automatically adds the generated node to the destination ExplodedNodeSet (autotransition) unless the client specifies otherwise with a bool flag. Several checkers did not call 'addTransition()' after calling 'GenerateNode()', causing the simulation path to be prematurely culled when a non-fail stop bug was encountered. 3) Add variants of GenerateNode()/GenerateSink() that take neither a Stmt* or a GRState*; most callers of GenerateNode() just pass in the same Stmt* as provided when the CheckerContext object is created; we can just use that the majority of the time. This cleanup also allows us to potentially coelesce the APIs for evaluating branches and end-of-paths (which currently directly use builders). 4) addTransition() no longer needs to be called except for a few cases. We now have a variant of addTransition() that takes a GRState*; this allows one to propagate the updated state without caring about generating a new node explicitly. This nicely cleaned up a bunch of cases that called autoTransition() with a bunch of conditional logic surround the call (that common logic has now been swallowed up by addTransition() itself). llvm-svn: 89707
98 lines
3.0 KiB
C++
98 lines
3.0 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/Analysis/PathSensitive/GRExprEngine.h"
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#include "clang/Analysis/PathSensitive/BugReporter.h"
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#include "clang/Analysis/PathSensitive/CheckerVisitor.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 VISIBILITY_HIDDEN 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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};
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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::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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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<100> buf;
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llvm::raw_svector_ostream os(buf);
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SourceRange range;
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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 {
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os << "Address of stack memory associated with local variable '"
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<< R->getString() << "' returned.";
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}
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RangedBugReport *report = new RangedBugReport(*BT, os.str(), N);
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report->addRange(RS->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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