From cdb685c83c83db1e778598867a9a65a9dbe3791a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <danielm77@spray.se>
Date: Mon, 29 Nov 2010 20:19:31 +0100
Subject: [PATCH] Fixed #2245 (False positive: Possible null pointer
 dereference)

---
 lib/checknullpointer.cpp | 9 ++++++++-
 test/testnullpointer.cpp | 8 ++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/checknullpointer.cpp b/lib/checknullpointer.cpp
index 6554946ae..86672e7d5 100644
--- a/lib/checknullpointer.cpp
+++ b/lib/checknullpointer.cpp
@@ -490,6 +490,13 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
                     break;
                 }
 
+                // parameters to sizeof are not dereferenced
+                if (Token::Match(tok2, "decltype|sizeof ("))
+                {
+                    tok2 = tok2->next()->link();
+                    continue;
+                }
+
                 // abort function..
                 if (Token::simpleMatch(tok2, ") ; }") &&
                     Token::Match(tok2->link()->tokAt(-2), "[;{}] %var% ("))
@@ -550,7 +557,7 @@ void CheckNullPointer::nullConstantDereference()
                     --indentlevel;
             }
 
-            if (tok->str() == "(" && Token::simpleMatch(tok->previous(), "sizeof"))
+            if (tok->str() == "(" && Token::Match(tok->previous(), "sizeof|decltype"))
                 tok = tok->link();
 
             else if (Token::simpleMatch(tok, "exit ( )"))
diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp
index 94e4f2b2f..38fa6db5e 100644
--- a/test/testnullpointer.cpp
+++ b/test/testnullpointer.cpp
@@ -154,6 +154,14 @@ private:
               "}\n");
         ASSERT_EQUALS("", errout.str());
 
+        // ticket #2245 - sizeof doesn't dereference
+        check("void f(Bar *p) {\n"
+              "    if (!p) {\n"
+              "        int sz = sizeof(p->x);\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
     }
 
     void nullpointer2()