str plus char: Added check and error message for str + ch

src/checkother.cpp

@@ -958,3 +958,28 @@ void CheckOther::functionVariableUsage()
         }
     }
 }
+//---------------------------------------------------------------------------
+
+
+
+
+
+
+//---------------------------------------------------------------------------
+// str plus char
+//---------------------------------------------------------------------------
+
+void CheckOther::strPlusChar()
+{
+    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next() )
+    {
+        if ( Token::Match(tok, "%str% + %any%") )
+        {
+            const char *s = tok->strAt(2);
+
+            // char constant..
+            if ( *s == '\'' )
+                _errorLogger->reportErr(ErrorMessage::strPlusChar(_tokenizer, tok));
+        }
+    }
+}

src/checkother.h

@@ -71,6 +71,9 @@ public:
     /** Unused function variables */
     void functionVariableUsage();
 
+    /** str plus char */
+    void strPlusChar();
+
 #ifndef UNIT_TESTING
 private:
 #endif

src/cppcheck.cpp

@@ -336,6 +336,10 @@ void CppCheck::checkFile(const std::string &code, const char FileName[])
     // mean that an ';' has been added by accident
     if (ErrorMessage::constStatement(_settings))
         checkOther.CheckIncompleteStatement();
+
+    // Unusual pointer arithmetic
+    if (ErrorMessage::strPlusChar(_settings))
+        checkOther.strPlusChar();
 }
 //---------------------------------------------------------------------------
 

src/errormessage.h

@@ -327,5 +327,14 @@ public:
         return s._checkCodingStyle;
     }
 
+    static std::string strPlusChar(const Tokenizer *tokenizer, const Token *Location)
+    {
+        return msg1(tokenizer, Location) + "Unusual pointer arithmetic";
+    }
+    static bool strPlusChar(const Settings &s)
+    {
+        return true;
+    }
+
 };
 #endif

test/testother.cpp

@@ -37,10 +37,12 @@ private:
         TEST_CASE(delete1);
         TEST_CASE(delete2);
 
-        TEST_CASE(sprintf1);    // Dangerous usage of sprintf
+        TEST_CASE(sprintf1);        // Dangerous usage of sprintf
         TEST_CASE(sprintf2);
         TEST_CASE(sprintf3);
-        TEST_CASE(sprintf4);    // struct member
+        TEST_CASE(sprintf4);        // struct member
+
+        TEST_CASE(strPlusChar1);     // "/usr" + '/'
     }
 
     void check(const char code[])
@@ -157,6 +159,36 @@ private:
         ASSERT_EQUALS(std::string(""), errout.str());
     }
 
+
+
+
+
+    void strPlusChar(const char code[])
+    {
+        // Tokenize..
+        Tokenizer tokenizer;
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+        tokenizer.setVarId();
+
+        // Clear the error buffer..
+        errout.str("");
+
+        // Check for redundant code..
+        CheckOther checkOther(&tokenizer, Settings(), this);
+        checkOther.strPlusChar();
+    }
+
+    void strPlusChar1()
+    {
+        // Strange looking pointer arithmetic..
+        strPlusChar("void foo()\n"
+                    "{\n"
+                    "    const char *p = \"/usr\" + '/';\n"
+                    "}\n");
+        ASSERT_EQUALS(std::string("[test.cpp:3]: Unusual pointer arithmetic\n"), errout.str());
+    }
+
 };
 
 REGISTER_TEST(TestOther)

tools/errmsg.cpp

@@ -94,6 +94,7 @@ int main()
     err.push_back(Message("variableScope", Message::never, "The scope of the variable %1 can be limited", "varname"));
     err.push_back(Message("ifAssignment", Message::style, "Assignment in if-condition"));
     err.push_back(Message("conditionAlwaysTrueFalse", Message::style, "Condition is always %1", "truefalse"));
+    err.push_back(Message("strPlusChar", Message::std, "Unusual pointer arithmetic"));
 
     // Generate code..
     std::cout << "Generate code.." << std::endl;