From 222e2a7620e6520ffaf4fc4e69d79c18da31542e Mon Sep 17 00:00:00 2001
From: "Zancanaro; Carlo" <czan8762@plang3.cs.usyd.edu.au>
Date: Mon, 24 Sep 2012 09:58:17 +1000
Subject: Add the clang library to the repo (with some of my changes, too).

---
 .../Checkers/UndefCapturedBlockVarChecker.cpp      | 105 +++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp

(limited to 'clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp')

diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
new file mode 100644
index 0000000..d57767e
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
@@ -0,0 +1,105 @@
+// 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 "ClangSACheckers.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class UndefCapturedBlockVarChecker
+  : public Checker< check::PostStmt<BlockExpr> > {
+ mutable OwningPtr<BugType> BT;
+
+public:
+  void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
+};
+} // end anonymous namespace
+
+static const DeclRefExpr *FindBlockDeclRefExpr(const Stmt *S,
+                                               const VarDecl *VD) {
+  if (const DeclRefExpr *BR = dyn_cast<DeclRefExpr>(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 DeclRefExpr *BR = FindBlockDeclRefExpr(child, VD);
+      if (BR)
+        return BR;
+    }
+
+  return NULL;
+}
+
+void
+UndefCapturedBlockVarChecker::checkPostStmt(const BlockExpr *BE,
+                                            CheckerContext &C) const {
+  if (!BE->getBlockDecl()->hasCaptures())
+    return;
+
+  ProgramStateRef state = C.getState();
+  const BlockDataRegion *R =
+    cast<BlockDataRegion>(state->getSVal(BE,
+                                         C.getLocationContext()).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.getLocationContext();
+    VR = C.getSValBuilder().getRegionManager().getVarRegion(VD, LC);
+    SVal VRVal = state->getSVal(VR);
+
+    if (VRVal.isUndef())
+      if (ExplodedNode *N = C.generateSink()) {
+        if (!BT)
+          BT.reset(new BuiltinBug("uninitialized variable captured by block"));
+
+        // Generate a bug report.
+        SmallString<128> buf;
+        llvm::raw_svector_ostream os(buf);
+
+        os << "Variable '" << VD->getName() 
+           << "' is uninitialized when captured by block";
+
+        BugReport *R = new BugReport(*BT, os.str(), N);
+        if (const Expr *Ex = FindBlockDeclRefExpr(BE->getBody(), VD))
+          R->addRange(Ex->getSourceRange());
+        R->addVisitor(new FindLastStoreBRVisitor(VRVal, VR));
+        // need location of block
+        C.EmitReport(R);
+      }
+  }
+}
+
+void ento::registerUndefCapturedBlockVarChecker(CheckerManager &mgr) {
+  mgr.registerChecker<UndefCapturedBlockVarChecker>();
+}
-- 
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