stl push_back: Added check (invalid iterator)

src/checkstl.cpp

@@ -203,3 +203,60 @@ void CheckStl::eraseCheckLoop(const Token *it)
 }
 
 
+
+
+
+void CheckStl::pushback()
+{
+    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
+    {
+        if (Token::Match(tok, "vector <"))
+        {
+            while (tok && tok->str() != ">")
+                tok = tok->next();
+            if (!tok)
+                break;
+            if (Token::Match(tok, "> :: iterator|const_iterator %var% =|;"))
+            {
+                const std::string iteratorname(tok->strAt(3));
+                std::string vectorname;
+                int indent = 0;
+                bool invalidIterator = false;
+                for (const Token *tok2 = tok;indent >= 0 && tok2; tok2 = tok2->next())
+                {
+                    if (tok2->str() == "{" || tok2->str() == "(")
+                        ++indent;
+                    else if (tok2->str() == "}" || tok2->str() == ")")
+                    {
+                        if (indent == 0 && Token::simpleMatch(tok2, ") {"))
+                            tok2 = tok2->next();
+                        else
+                            --indent;
+                    }
+
+                    // Assigning iterator..
+                    if (Token::Match(tok2, (iteratorname + " = %var% . begin ( )").c_str()))
+                    {
+                        vectorname = tok2->strAt(2);
+                        invalidIterator = false;
+                    }
+
+                    // push_back on vector..
+                    if (vectorname.size() && Token::Match(tok2, (vectorname + " . push_front|push_back").c_str()))
+                        invalidIterator = true;
+
+                    // Using invalid iterator..
+                    if (invalidIterator)
+                    {
+                        if (Token::Match(tok2, ("++|--|*|+|-|(|, " + iteratorname).c_str()))
+                            _errorLogger->pushback(_tokenizer, tok2, iteratorname);
+                        if (Token::Match(tok2, (iteratorname + " ++|--|+|-").c_str()))
+                            _errorLogger->pushback(_tokenizer, tok2, iteratorname);
+                    }
+                }
+            }
+        }
+    }
+}
+
+

src/checkstl.h

@@ -51,6 +51,11 @@ public:
      */
     void erase();
 
+    /**
+     * Dangerous usage of push_back
+     */
+    void pushback();
+
 private:
     const Tokenizer *_tokenizer;
     ErrorLogger *_errorLogger;

src/cppcheck.cpp

@@ -421,6 +421,9 @@ void CppCheck::checkFile(const std::string &code, const char FileName[])
 
     if (ErrorLogger::erase())
         checkStl.erase();
+
+    if (ErrorLogger::pushback())
+        checkStl.pushback();
 }
 
 Settings CppCheck::settings() const

src/errorlogger.h

@@ -450,6 +450,15 @@ public:
         return true;
     }
 
+    void pushback(const Tokenizer *tokenizer, const Token *Location, const std::string &iterator_name)
+    {
+        _writemsg(tokenizer, Location, "error", "After push_back or push_front, the iterator '" + iterator_name + "' may be invalid", "pushback");
+    }
+    static bool pushback()
+    {
+        return true;
+    }
+
 
     static std::string callStackToString(const std::list<ErrorLogger::ErrorMessage::FileLocation> &callStack);
 

test/teststl.cpp

@@ -45,6 +45,8 @@ private:
         TEST_CASE(eraseReturn);
         TEST_CASE(eraseGoto);
         TEST_CASE(eraseAssign);
+
+        TEST_CASE(pushback1);
     }
 
     void check(const char code[])
@@ -215,6 +217,37 @@ private:
 
 
 
+
+
+
+    void checkPushback(const char code[])
+    {
+        // Tokenize..
+        Tokenizer tokenizer;
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+
+        // Clear the error buffer..
+        errout.str("");
+
+        // Check char variable usage..
+        CheckStl checkStl(&tokenizer, this);
+        checkStl.pushback();
+    }
+
+
+    void pushback1()
+    {
+        checkPushback("void f()\n"
+                      "{\n"
+                      "    std::vector<int>::const_iterator it = foo.begin();\n"
+                      "    foo.push_back(123);\n"
+                      "    *it;\n"
+                      "}\n");
+        ASSERT_EQUALS("[test.cpp:5]: (error) After push_back or push_front, the iterator 'it' may be invalid\n", errout.str());
+    }
+
+
 };
 
 REGISTER_TEST(TestStl)

tools/errmsg.cpp

@@ -114,7 +114,7 @@ int main()
     // checkstl.cpp..
     err.push_back(Message("iteratorUsage", Message::error, "Same iterator is used with both %1 and %2", "container1", "container2"));
     err.push_back(Message("erase", Message::error, "Dangerous usage of erase"));
-
+    err.push_back(Message("pushback", Message::error, "After push_back or push_front, the iterator '%1' may be invalid", "iterator_name"));
 
 
     // Generate code..