str plus char: added simple variable handling

src/checkother.cpp

@@ -971,15 +971,30 @@ void CheckOther::functionVariableUsage()
 
 void CheckOther::strPlusChar()
 {
+    bool charVars[10000] = {0};
+
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
     {
-        if (Token::Match(tok, "%str% + %any%"))
+        // Declaring char variable..
+        if (Token::Match(tok, "char %var% [;=]"))
         {
-            const char *s = tok->strAt(2);
+            unsigned int varid = tok->next()->varId();
+            if (varid>0 && varid<10000)
+                charVars[varid] = true;
+        }
 
+        //
+        else if (Token::Match(tok, "%str% + %any%"))
+        {
             // char constant..
+            const char *s = tok->strAt(2);
             if (*s == '\'')
                 _errorLogger->reportErr(ErrorMessage::strPlusChar(_tokenizer, tok));
+
+            // char variable..
+            unsigned int varid = tok->tokAt(2)->varId();
+            if (varid>0 && varid<10000 && charVars[varid])
+                _errorLogger->reportErr(ErrorMessage::strPlusChar(_tokenizer, tok));
         }
     }
 }

test/testother.cpp

@@ -43,6 +43,7 @@ private:
         TEST_CASE(sprintf4);        // struct member
 
         TEST_CASE(strPlusChar1);     // "/usr" + '/'
+        TEST_CASE(strPlusChar2);     // "/usr" + ch
     }
 
     void check(const char code[])
@@ -189,6 +190,17 @@ private:
         ASSERT_EQUALS(std::string("[test.cpp:3]: Unusual pointer arithmetic\n"), errout.str());
     }
 
+    void strPlusChar2()
+    {
+        // Strange looking pointer arithmetic..
+        strPlusChar("void foo()\n"
+                    "{\n"
+                    "    char ch = '/';\n"
+                    "    const char *p = \"/usr\" + ch;\n"
+                    "}\n");
+        ASSERT_EQUALS(std::string("[test.cpp:4]: Unusual pointer arithmetic\n"), errout.str());
+    }
+
 };
 
 REGISTER_TEST(TestOther)