Add simpler checker to check if variables captured by a block are uninitialized.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@96341 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Checker/UndefCapturedBlockVarChecker.cpp b/lib/Checker/UndefCapturedBlockVarChecker.cpp
new file mode 100644
index 0000000..a8d7284
--- /dev/null
+++ b/lib/Checker/UndefCapturedBlockVarChecker.cpp
@@ -0,0 +1,101 @@
+// 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);
+ }
+ }
+}