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// UndefCapturedBlockVarChecker.cpp - Uninitialized captured vars -*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This checker detects blocks that capture uninitialized values.
//
//===----------------------------------------------------------------------===//
#include "GRExprEngineInternalChecks.h"
#include "clang/Checker/PathSensitive/CheckerVisitor.h"
#include "clang/Checker/PathSensitive/GRExprEngine.h"
#include "clang/Checker/BugReporter/BugReporter.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
namespace {
class UndefCapturedBlockVarChecker
: public CheckerVisitor<UndefCapturedBlockVarChecker> {
BugType *BT;
public:
UndefCapturedBlockVarChecker() : BT(0) {}
static void *getTag() { static int tag = 0; return &tag; }
void PostVisitBlockExpr(CheckerContext &C, const BlockExpr *BE);
};
} // end anonymous namespace
void clang::RegisterUndefCapturedBlockVarChecker(GRExprEngine &Eng) {
Eng.registerCheck(new UndefCapturedBlockVarChecker());
}
static const BlockDeclRefExpr *FindBlockDeclRefExpr(const Stmt *S,
const VarDecl *VD){
if (const BlockDeclRefExpr *BR = dyn_cast<BlockDeclRefExpr>(S))
if (BR->getDecl() == VD)
return BR;
for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end();
I!=E; ++I)
if (const Stmt *child = *I) {
const BlockDeclRefExpr *BR = FindBlockDeclRefExpr(child, VD);
if (BR)
return BR;
}
return NULL;
}
void
UndefCapturedBlockVarChecker::PostVisitBlockExpr(CheckerContext &C,
const BlockExpr *BE) {
if (!BE->hasBlockDeclRefExprs())
return;
const GRState *state = C.getState();
const BlockDataRegion *R =
cast<BlockDataRegion>(state->getSVal(BE).getAsRegion());
BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(),
E = R->referenced_vars_end();
for (; I != E; ++I) {
// This VarRegion is the region associated with the block; we need
// the one associated with the encompassing context.
const VarRegion *VR = *I;
const VarDecl *VD = VR->getDecl();
if (VD->getAttr<BlocksAttr>() || !VD->hasLocalStorage())
continue;
// Get the VarRegion associated with VD in the local stack frame.
const LocationContext *LC = C.getPredecessor()->getLocationContext();
VR = C.getValueManager().getRegionManager().getVarRegion(VD, LC);
if (state->getSVal(VR).isUndef())
if (ExplodedNode *N = C.GenerateSink()) {
if (!BT)
BT = new BuiltinBug("Captured block variable is uninitialized");
// Generate a bug report.
llvm::SmallString<128> buf;
llvm::raw_svector_ostream os(buf);
os << "Variable '" << VD->getName() << "' is captured by block with "
"a garbage value";
EnhancedBugReport *R = new EnhancedBugReport(*BT, os.str(), N);
if (const Expr *Ex = FindBlockDeclRefExpr(BE->getBody(), VD))
R->addRange(Ex->getSourceRange());
R->addVisitorCreator(bugreporter::registerFindLastStore, VR);
// need location of block
C.EmitReport(R);
}
}
}
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