16704bb15b
improved the pruning heuristics. The current heuristics are pretty good, but they make diagnostics for uninitialized variables warnings particularly useless in some cases. llvm-svn: 157734
107 lines
3.5 KiB
C++
107 lines
3.5 KiB
C++
// UndefCapturedBlockVarChecker.cpp - Uninitialized captured vars -*- 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 checker detects blocks that capture uninitialized values.
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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/PathSensitive/ExprEngine.h"
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#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/Support/raw_ostream.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 UndefCapturedBlockVarChecker
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: public Checker< check::PostStmt<BlockExpr> > {
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mutable OwningPtr<BugType> BT;
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public:
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void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
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};
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} // end anonymous namespace
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static const DeclRefExpr *FindBlockDeclRefExpr(const Stmt *S,
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const VarDecl *VD) {
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if (const DeclRefExpr *BR = dyn_cast<DeclRefExpr>(S))
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if (BR->getDecl() == VD)
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return BR;
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for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end();
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I!=E; ++I)
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if (const Stmt *child = *I) {
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const DeclRefExpr *BR = FindBlockDeclRefExpr(child, VD);
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if (BR)
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return BR;
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}
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return NULL;
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}
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void
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UndefCapturedBlockVarChecker::checkPostStmt(const BlockExpr *BE,
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CheckerContext &C) const {
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if (!BE->getBlockDecl()->hasCaptures())
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return;
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ProgramStateRef state = C.getState();
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const BlockDataRegion *R =
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cast<BlockDataRegion>(state->getSVal(BE,
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C.getLocationContext()).getAsRegion());
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BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(),
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E = R->referenced_vars_end();
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for (; I != E; ++I) {
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// This VarRegion is the region associated with the block; we need
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// the one associated with the encompassing context.
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const VarRegion *VR = *I;
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const VarDecl *VD = VR->getDecl();
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if (VD->getAttr<BlocksAttr>() || !VD->hasLocalStorage())
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continue;
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// Get the VarRegion associated with VD in the local stack frame.
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const LocationContext *LC = C.getLocationContext();
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VR = C.getSValBuilder().getRegionManager().getVarRegion(VD, LC);
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SVal VRVal = state->getSVal(VR);
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if (VRVal.isUndef())
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if (ExplodedNode *N = C.generateSink()) {
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if (!BT)
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BT.reset(new BuiltinBug("uninitialized variable captured by block"));
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// Generate a bug report.
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SmallString<128> buf;
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llvm::raw_svector_ostream os(buf);
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os << "Variable '" << VD->getName()
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<< "' is uninitialized when captured by block";
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BugReport *R = new BugReport(*BT, os.str(), N);
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if (const Expr *Ex = FindBlockDeclRefExpr(BE->getBody(), VD))
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R->addRange(Ex->getSourceRange());
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R->addVisitor(new FindLastStoreBRVisitor(VRVal, VR));
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R->disablePathPruning();
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// need location of block
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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::registerUndefCapturedBlockVarChecker(CheckerManager &mgr) {
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mgr.registerChecker<UndefCapturedBlockVarChecker>();
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}
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