From a90a7202cbd4ee2a73e452217034eb6fdadac5ef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <danielm77@spray.se>
Date: Fri, 5 Nov 2010 17:04:41 +0100
Subject: [PATCH] Uninitialized variables: detect usage of dead pointer: '*p +=
 10'

---
 lib/checkuninitvar.cpp | 21 ++++++++++++++++++++-
 test/testuninitvar.cpp |  3 +--
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index 923e4c753..71d232f48 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -486,9 +486,28 @@ private:
             if (Token::Match(tok.tokAt(-2), "[;{}] *"))
             {
                 if (Token::simpleMatch(tok.next(), "="))
-                    init_pointer(checks, &tok);
+                {
+                    // is the pointer used in the rhs?
+                    bool used = false;
+                    for (const Token *tok2 = tok.tokAt(2); tok2; tok2 = tok2->next())
+                    {
+                        if (Token::Match(tok2, "[,;=(]"))
+                            break;
+                        else if (Token::Match(tok2, "* %varid%", tok.varId()))
+                        {
+                            used = true;
+                            break;
+                        }
+                    }
+                    if (used)
+                        use_pointer(checks, &tok);
+                    else
+                        init_pointer(checks, &tok);
+                }
                 else
+                {
                     use_pointer(checks, &tok);
+                }
                 return &tok;
             }
 
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 50ef4c239..402df2c6f 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -376,8 +376,7 @@ private:
                        "    char *s = malloc(100);\n"
                        "    *s += 10;\n"
                        "}\n");
-        TODO_ASSERT_EQUALS("[test.cpp:4]: (error) Data is allocated but not initialized: s\n", errout.str());
-        ASSERT_EQUALS("", errout.str());
+        ASSERT_EQUALS("[test.cpp:4]: (error) Data is allocated but not initialized: s\n", errout.str());
 
         checkUninitVar("void f()\n"
                        "{\n"