Chris Lattner has strong opinions about directory

layout.  :)

Rename the 'EntoSA' directories to 'StaticAnalyzer'.

Internally we will still use the 'ento' namespace
for the analyzer engine (unless there are further
sabre rattlings...).

llvm-svn: 122514

clang/lib/StaticAnalyzer/Checkers/CastToStructChecker.cpp

@@ -0,0 +1,79 @@
+//=== 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 "clang/StaticAnalyzer/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/PathSensitive/CheckerVisitor.h"
+#include "ExprEngineInternalChecks.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class 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->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.generateNode()) {
+      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(), N);
+      R->addRange(CE->getSourceRange());
+      C.EmitReport(R);
+    }
+  }
+}
+
+void ento::RegisterCastToStructChecker(ExprEngine &Eng) {
+  Eng.registerCheck(new CastToStructChecker());
+}