Fixed ticket #411 (false positive: resource leak in while loop)

src/checkmemoryleak.cpp

@@ -992,6 +992,7 @@ void CheckMemoryLeakInFunction::simplifycode(Token *tok, bool &all)
     bool done = false;
     while (! done)
     {
+        //tok->printOut("simplifycode loop..");
         done = true;
 
         for (Token *tok2 = tok; tok2; tok2 = tok2 ? tok2->next() : NULL)
@@ -1258,13 +1259,6 @@ void CheckMemoryLeakInFunction::simplifycode(Token *tok, bool &all)
                 done = false;
             }
 
-            // Replace "loop !var alloc ;" with " alloc ;"
-            if (Token::Match(tok2->next(), "loop !var alloc ;"))
-            {
-                Token::eraseTokens(tok2, tok2->tokAt(3));
-                done = false;
-            }
-
             // Replace "loop if return ;" with "if return ;"
             if (Token::simpleMatch(tok2->next(), "loop if return"))
             {

src/tokenize.cpp

@@ -2282,11 +2282,17 @@ void Tokenizer::unsignedint()
 bool Tokenizer::simplifyIfAssign()
 {
     bool ret = false;
+
     for (Token *tok = _tokens; tok; tok = tok->next())
     {
-        if (Token::Match(tok->next(), "if ( (| %var% =") ||
-            Token::Match(tok->next(), "if ( ! ( %var% ="))
+        if (Token::Match(tok->next(), "if|while ( (| %var% =") ||
+            Token::Match(tok->next(), "if|while ( ! ( %var% ="))
         {
+            ret = true;
+
+            // simplifying a "while" condition ?
+            const bool iswhile(tok->next()->str() == "while");
+
             // delete the "if"
             tok->deleteNext();
 
@@ -2321,7 +2327,7 @@ bool Tokenizer::simplifyIfAssign()
                 }
             }
 
-            // Insert "; if ( .."
+            // Insert "; if|while ( .."
             if (tok2)
             {
                 tok2 = tok2->previous();
@@ -2330,9 +2336,37 @@ bool Tokenizer::simplifyIfAssign()
                     tok2->insertToken("(");
                 if (isNot)
                     tok2->next()->insertToken("!");
-                tok2->insertToken("if");
+                tok2->insertToken(iswhile ? "while" : "if");
                 tok2->insertToken(";");
-                ret = true;
+
+                // If it's a while loop.. insert the assignment in the loop
+                if (iswhile)
+                {
+                    indentlevel = 0;
+                    Token *tok3 = tok2;
+                    for (tok3 = tok2; tok3; tok3 = tok3->next())
+                    {
+                        if (tok3->str() == "{")
+                            ++indentlevel;
+                        else if (tok3->str() == "}")
+                        {
+                            if (indentlevel <= 1)
+                                break;
+                            --indentlevel;
+                        }
+                    }
+
+                    if (tok3 && indentlevel == 1)
+                    {
+                        tok3 = tok3->previous();
+                        for (tok2 = tok2->next(); tok2 && tok2 != tok; tok2 = tok2->previous())
+                        {
+                            tok3->insertToken(tok2->str().c_str());
+                            tok3->next()->fileIndex(tok2->fileIndex());
+                            tok3->next()->linenr(tok2->linenr());
+                        }
+                    }
+                }
             }
         }
     }

test/testmemleak.cpp

@@ -169,6 +169,7 @@ private:
         TEST_CASE(forwhile8);       // Bug 2429936
         TEST_CASE(forwhile9);
         TEST_CASE(forwhile10);
+        TEST_CASE(forwhile11);
 
         TEST_CASE(dowhile1);
 
@@ -1027,6 +1028,18 @@ private:
     }
 
 
+    void forwhile11()
+    {
+        check("int main()\n"
+              "{\n"
+              "    FILE *stream=NULL;\n"
+              "    while((stream = fopen(name,\"r\")) == NULL)\n"
+              "    { }\n"
+              "    if(stream!=NULL) fclose(stream);\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
 
 
 

test/testsimplifytokens.cpp

@@ -100,6 +100,7 @@ private:
 
         // Assignment in condition..
         TEST_CASE(ifassign1);
+        TEST_CASE(whileAssign);
 
         // "if(0==x)" => "if(!x)"
         TEST_CASE(ifnot);
@@ -938,6 +939,14 @@ private:
     }
 
 
+    void whileAssign()
+    {
+        ASSERT_EQUALS("; a = b ; while ( a ) { b = 0 ; a = b ; }", simplifyIfAssign(";while(a=b) { b = 0; }"));
+        //ASSERT_EQUALS("; a = b ( ) ; if ( ( a ) ) ;", simplifyIfAssign(";if((a=b()));"));
+        //ASSERT_EQUALS("; a = b ( ) ; if ( ! ( a ) ) ;", simplifyIfAssign(";if(!(a=b()));"));
+    }
+
+
     std::string simplifyIfNot(const char code[])
     {
         // tokenize..