[clang] [analyzer] Conversion to CheckerFamily: DereferenceChecker (PR #150442)

[Donát Nagy via cfe-commits]

================
@@ -158,115 +172,85 @@ static bool isDeclRefExprToReference(const Expr *E) {
   return false;
 }
 
-void DereferenceChecker::reportBug(DerefKind K, ProgramStateRef State,
-                                   const Stmt *S, CheckerContext &C) const {
-  const BugType *BT = nullptr;
-  llvm::StringRef DerefStr1;
-  llvm::StringRef DerefStr2;
-  switch (K) {
-  case DerefKind::NullPointer:
-    if (!CheckNullDereference) {
-      C.addSink();
-      return;
-    }
-    BT = BT_Null.get();
-    DerefStr1 = " results in a null pointer dereference";
-    DerefStr2 = " results in a dereference of a null pointer";
-    break;
-  case DerefKind::UndefinedPointerValue:
-    if (!CheckNullDereference) {
-      C.addSink();
+void DereferenceChecker::reportBug(const DerefBugType &BT,
+                                   ProgramStateRef State, const Stmt *S,
+                                   CheckerContext &C) const {
+  if (&BT == &FixedAddressBug) {
+    if (!FixedDerefChecker.isEnabled())
----------------
NagyDonat wrote:

```suggestion
    if (!FixedDerefChecker.isEnabled())
      // Deliberately don't add a sink node if check is disabled.
      // This situation may be valid in special cases.
```
Oops, I forgot to preserve this comment when I refactored this function.

https://github.com/llvm/llvm-project/pull/150442