CheckNullPointer::isPointerDeRef: Tweaks to reduce false warnings when inconclusive is used.

lib/checkbufferoverrun.cpp

@@ -83,7 +83,7 @@ static std::string bufferOverrunMessage(std::string varnames)
     std::string errmsg("Buffer access out-of-bounds");
     if (!varnames.empty())
         errmsg += ": " + varnames;
-    
+
     return errmsg;
 }
 

lib/checknullpointer.cpp

@@ -254,6 +254,15 @@ bool CheckNullPointer::isPointerDeRef(const Token *tok, bool &unknown)
     if (Token::Match(tok->previous(), "delete %var%") || Token::Match(tok->tokAt(-3), "delete [ ] %var%"))
         return false;
 
+    // OK to check if pointer is null
+    // OK to take address of pointer
+    if (Token::Match(tok->previous(), "!|& %var% )|,|&&|%oror%"))
+        return false;
+
+    // OK to pass pointer to function
+    if (Token::Match(tok->previous(), ", %var% [,)]"))
+        return false;
+
     // unknown if it's a dereference
     unknown = true;