From af1e51f6489a33695499c84695d2c3543bdc93cb Mon Sep 17 00:00:00 2001
From: Robert Reif <reif@earthlink.net>
Date: Thu, 14 Jul 2011 20:45:27 -0400
Subject: [PATCH] fix some more false negatives for #2904 (Memory leak not
 detected when creating a new class instance)

---
 lib/checkmemoryleak.cpp | 28 +++++++++++++---------------
 lib/checkmemoryleak.h   |  2 +-
 test/testmemleak.cpp    | 15 +++++++++++++++
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/lib/checkmemoryleak.cpp b/lib/checkmemoryleak.cpp
index 2528f4fd3..4f985b044 100644
--- a/lib/checkmemoryleak.cpp
+++ b/lib/checkmemoryleak.cpp
@@ -82,23 +82,21 @@ static int call_func_white_list_compare(const void *a, const void *b)
 
 //---------------------------------------------------------------------------
 
-bool CheckMemoryLeak::isclass(const Tokenizer *_tokenizer, const Token *tok) const
+bool CheckMemoryLeak::isclass(const Tokenizer *_tokenizer, const Token *tok, unsigned int varid) const
 {
     if (tok->isStandardType())
         return false;
 
-    // return false if the type is a simple struct without member functions
-    const std::string pattern("struct|class " + tok->str() + " {");
-    const Token *tok2 = Token::findmatch(_tokenizer->tokens(), pattern.c_str());
-    if (tok2)
-    {
-        while (tok2 && tok2->str() != "}" && tok2->str() != "(")
-            tok2 = tok2->next();
+    const Variable * var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(varid);
 
-        // Simple struct => return false
-        if (tok2 && tok2->str() == "}")
-            return false;
-    }
+    // return false if the type is a simple record type without side effects
+    // a type that has no side effects (no constructors and no members with constructors)
+    /** @todo false negative: check base class for side effects */
+    /** @todo false negative: check constructors for side effects */
+    if (var && var->type() && var->type()->numConstructors == 0 &&
+        (var->type()->varlist.empty() || var->type()->needInitialization == Scope::True) &&
+        var->type()->derivedFrom.empty())
+        return false;
 
     return true;
 }
@@ -1039,21 +1037,21 @@ Token *CheckMemoryLeakInFunction::getcode(const Token *tok, std::list<const Toke
                 {
                     if (Token::Match(tok->tokAt(2), "new %type% [(;]"))
                     {
-                        if (isclass(_tokenizer, tok->tokAt(3)))
+                        if (isclass(_tokenizer, tok->tokAt(3), varid))
                         {
                             alloc = No;
                         }
                     }
                     else if (Token::Match(tok->tokAt(2), "new ( nothrow ) %type%"))
                     {
-                        if (isclass(_tokenizer, tok->tokAt(6)))
+                        if (isclass(_tokenizer, tok->tokAt(6), varid))
                         {
                             alloc = No;
                         }
                     }
                     else if (Token::Match(tok->tokAt(2), "new ( std :: nothrow ) %type%"))
                     {
-                        if (isclass(_tokenizer, tok->tokAt(8)))
+                        if (isclass(_tokenizer, tok->tokAt(8), varid))
                         {
                             alloc = No;
                         }
diff --git a/lib/checkmemoryleak.h b/lib/checkmemoryleak.h
index f82918ab9..2a036efc7 100644
--- a/lib/checkmemoryleak.h
+++ b/lib/checkmemoryleak.h
@@ -127,7 +127,7 @@ public:
      * @param typestr type name
      * @return true if the type name is the name of a class
      */
-    bool isclass(const Tokenizer *_tokenizer, const Token *typestr) const;
+    bool isclass(const Tokenizer *_tokenizer, const Token *typestr, unsigned int varid) const;
 
     void memleakError(const Token *tok, const std::string &varname);
     void resourceLeakError(const Token *tok, const std::string &varname);
diff --git a/test/testmemleak.cpp b/test/testmemleak.cpp
index 20cc153f5..abb9d7ec9 100644
--- a/test/testmemleak.cpp
+++ b/test/testmemleak.cpp
@@ -2236,6 +2236,21 @@ private:
               "  Fred *f = new Fred();\n"
               "}\n");
         ASSERT_EQUALS("[test.cpp:5]: (error) Memory leak: f\n", errout.str());
+
+        check("class Fred { void foo(){ } };\n"
+              "void f(void) \n"
+              "{\n"
+              "  Fred *f = new Fred();\n"
+              "  delete f;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        check("class Fred { void foo(){ } };\n"
+              "void f(void) \n"
+              "{\n"
+              "  Fred *f = new Fred();\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:5]: (error) Memory leak: f\n", errout.str());
     }
 
     void allocfunc1()