Add checker for CWE-588: Attempt to Access Child of a Non-structure Pointer.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86529 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CastToStructChecker.cpp b/lib/Analysis/CastToStructChecker.cpp
new file mode 100644
index 0000000..5d0110e
--- /dev/null
+++ b/lib/Analysis/CastToStructChecker.cpp
@@ -0,0 +1,78 @@
+//=== 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
+// assignment of a fixed address to a pointer.
+// This check corresponds to CWE-588.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/PathSensitive/CheckerVisitor.h"
+#include "GRExprEngineInternalChecks.h"
+
+using namespace clang;
+
+namespace {
+class VISIBILITY_HIDDEN CastToStructChecker
+ : public CheckerVisitor<CastToStructChecker> {
+ BuiltinBug *BT;
+public:
+ CastToStructChecker() : BT(0) {}
+ static void *getTag();
+ void PreVisitCastExpr(CheckerContext &C, const CastExpr *B);
+};
+}
+
+void *CastToStructChecker::getTag() {
+ static int x;
+ return &x;
+}
+
+void CastToStructChecker::PreVisitCastExpr(CheckerContext &C,
+ const CastExpr *CE) {
+ const Expr *E = CE->getSubExpr();
+ ASTContext &Ctx = C.getASTContext();
+ QualType OrigTy = Ctx.getCanonicalType(E->getType());
+ QualType ToTy = Ctx.getCanonicalType(CE->getType());
+
+ PointerType *OrigPTy = dyn_cast<PointerType>(OrigTy.getTypePtr());
+ PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
+
+ if (!ToPTy || !OrigPTy)
+ return;
+
+ QualType OrigPointeeTy = OrigPTy->getPointeeType();
+ QualType ToPointeeTy = ToPTy->getPointeeType();
+
+ if (!ToPointeeTy->isRecordType())
+ 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.GenerateNode(CE)) {
+ if (!BT)
+ BT = 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.");
+ RangedBugReport *R = new RangedBugReport(*BT,BT->getDescription().c_str(),
+ N);
+ R->addRange(CE->getSourceRange());
+ C.EmitReport(R);
+ }
+ }
+}
+
+void clang::RegisterCastToStructChecker(GRExprEngine &Eng) {
+ Eng.registerCheck(new CastToStructChecker());
+}