STL: added check for dangerous usage of std::find (#829)

lib/checkstl.cpp

@@ -482,3 +482,35 @@ void CheckStl::stlBoundriesError(const Token *tok, const std::string &container_
 {
     reportError(tok, Severity::error, "stlBoundries", container_name + " range check should use != and not < since the order of the pointers isn't guaranteed");
 }
+
+
+
+void CheckStl::find()
+{
+    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
+    {
+        if (tok->str() != ";")
+            continue;
+        if (!Token::Match(tok->next(), "%var% = std :: find ("))
+            continue;
+        const unsigned int iteratorid = tok->next()->varId();
+        if (iteratorid == 0)
+            continue;
+        tok = tok->tokAt(6)->link();
+        if (!tok)
+            break;
+        for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
+        {
+            if (tok2->str() == "{" || tok2->str() == "}" || tok2->str() == "(" || tok2->str() == ")")
+                break;
+            if (tok2->varId() == iteratorid && Token::simpleMatch(tok2->previous(), "*"))
+                findError(tok2);
+        }        
+    }
+}
+    
+    
+void CheckStl::findError(const Token *tok)
+{
+    reportError(tok, Severity::error, "stlfind", "dangerous usage of find result");    
+}

lib/checkstl.h

@@ -53,6 +53,7 @@ public:
         checkStl.erase();
         checkStl.pushback();
         checkStl.stlBoundries();
+        checkStl.find();
     }
 
 
@@ -91,6 +92,9 @@ public:
      * bad condition.. "it < alist.end()"
      */
     void stlBoundries();
+    
+    /** usage of std::find */
+    void find();
 
 private:
 
@@ -108,6 +112,7 @@ private:
     void invalidIteratorError(const Token *tok, const std::string &func, const std::string &iterator_name);
     void invalidPointerError(const Token *tok, const std::string &pointer_name);
     void stlBoundriesError(const Token *tok, const std::string &container_name);
+    void findError(const Token *tok);
 
     void getErrorMessages()
     {
@@ -119,6 +124,7 @@ private:
         invalidIteratorError(0, "push_back|push_front|insert", "iterator");
         invalidPointerError(0, "pointer");
         stlBoundriesError(0, "container");
+        findError(0);
     }
 
     std::string name() const
@@ -133,7 +139,8 @@ private:
                " * misuse of iterators when iterating through a container\n"
                " * mismatching containers in calls\n"
                " * dereferencing an erased iterator\n"
-               " * for vectors: using iterator/pointer after push_back has been used\n";
+               " * for vectors: using iterator/pointer after push_back has been used\n"
+               " * dangerous usage of find";
     }
 };
 /// @}

test/teststl.cpp

@@ -68,6 +68,9 @@ private:
         TEST_CASE(stlBoundries1);
         TEST_CASE(stlBoundries2);
         TEST_CASE(stlBoundries3);
+        
+        // find
+        TEST_CASE(find1);
     }
 
     void check(const char code[])
@@ -571,6 +574,17 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+
+    void find1()
+    {
+        check("void f(std::vector<int> &ints)\n"
+              "{\n"
+              "    std::vector<int>::iterator it = std::find(ints.begin(), ints.end(), 33);\n"
+              "    *it = 11;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
 };
 
 REGISTER_TEST(TestStl)