Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 74 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/CastToStructChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CastToStructChecker.cpp
new file mode 100644
index 0000000..1407638
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/CastToStructChecker.cpp
@@ -0,0 +1,74 @@
+//=== CastToStructChecker.cpp - Fixed address usage checker ----*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This files defines CastToStructChecker, a builtin checker that checks for
+// cast from non-struct pointer to struct pointer.
+// This check corresponds to CWE-588.
+//
+//===----------------------------------------------------------------------===//
+
+#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/BugReporter/BugType.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class CastToStructChecker : public Checker< check::PreStmt<CastExpr> > {
+  mutable OwningPtr<BuiltinBug> BT;
+
+public:
+  void checkPreStmt(const CastExpr *CE, CheckerContext &C) const;
+};
+}
+
+void CastToStructChecker::checkPreStmt(const CastExpr *CE,
+                                       CheckerContext &C) const {
+  const Expr *E = CE->getSubExpr();
+  ASTContext &Ctx = C.getASTContext();
+  QualType OrigTy = Ctx.getCanonicalType(E->getType());
+  QualType ToTy = Ctx.getCanonicalType(CE->getType());
+
+  const PointerType *OrigPTy = dyn_cast<PointerType>(OrigTy.getTypePtr());
+  const PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
+
+  if (!ToPTy || !OrigPTy)
+    return;
+
+  QualType OrigPointeeTy = OrigPTy->getPointeeType();
+  QualType ToPointeeTy = ToPTy->getPointeeType();
+
+  if (!ToPointeeTy->isStructureOrClassType())
+    return;
+
+  // We allow cast from void*.
+  if (OrigPointeeTy->isVoidType())
+    return;
+
+  // Now the cast-to-type is struct pointer, the original type is not void*.
+  if (!OrigPointeeTy->isRecordType()) {
+    if (ExplodedNode *N = C.addTransition()) {
+      if (!BT)
+        BT.reset(new BuiltinBug("Cast from non-struct type to struct type",
+                            "Casting a non-structure type to a structure type "
+                            "and accessing a field can lead to memory access "
+                            "errors or data corruption."));
+      BugReport *R = new BugReport(*BT,BT->getDescription(), N);
+      R->addRange(CE->getSourceRange());
+      C.EmitReport(R);
+    }
+  }
+}
+
+void ento::registerCastToStructChecker(CheckerManager &mgr) {
+  mgr.registerChecker<CastToStructChecker>();
+}