Added test CheckOther::sizeofsizeof. Inspired by #1682

lib/checkother.cpp

@@ -3636,3 +3636,21 @@ void CheckOther::fflushOnInputStreamError(const Token *tok, const std::string &v
     reportError(tok, Severity::error,
                 "fflushOnInputStream", "fflush() called on input stream \"" + varname + "\" may result in undefined behaviour");
 }
+
+
+void CheckOther::sizeofsizeof()
+{
+    if (!_settings->_checkCodingStyle)
+        return;
+    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
+    {
+        if (Token::simpleMatch(tok, "sizeof sizeof"))
+            sizeofsizeofError(tok);
+    }
+}
+
+void CheckOther::sizeofsizeofError(const Token *tok)
+{
+    reportError(tok, Severity::style,
+                "sizeofsizeof", "Suspicios code 'sizeof sizeof ..', most likely there should only be one sizeof. The current code is equivalent with 'sizeof(size_t)'.");
+}

lib/checkother.h

@@ -60,6 +60,7 @@ public:
         checkOther.checkVariableScope();
         checkOther.checkStructMemberUsage();
         checkOther.strPlusChar();
+        checkOther.sizeofsizeof();
     }
 
     /** @brief Run checks against the simplified token list */
@@ -162,6 +163,10 @@ public:
     /** @brief %Check for using fflush() on an input stream*/
     void checkFflushOnInputStream();
 
+    /** @brief %Check for 'sizeof sizeof ..' */
+    void sizeofsizeof();
+    void sizeofsizeofError(const Token *tok);
+
     // Error messages..
     void cstyleCastError(const Token *tok);
     void redundantIfDelete0Error(const Token *tok);
@@ -217,6 +222,7 @@ public:
         variableScopeError(0, "varname");
         conditionAlwaysTrueFalse(0, "true/false");
         strPlusChar(0);
+        sizeofsizeofError(0);
 
         // optimisations
         postIncrementError(0, "varname", true);

test/testother.cpp

@@ -94,6 +94,8 @@ private:
         TEST_CASE(emptyStringTest);
 
         TEST_CASE(fflushOnInputStreamTest);
+
+        TEST_CASE(sizeofsizeof);
     }
 
     void check(const char code[])
@@ -103,16 +105,19 @@ private:
         std::istringstream istr(code);
         tokenizer.tokenize(istr, "test.cpp");
 
-        // Simplify token list..
-        tokenizer.simplifyTokenList();
-
-        // Clear the error buffer..
-        errout.str("");
-
         // Check..
         Settings settings;
         settings._checkCodingStyle = true;
         CheckOther checkOther(&tokenizer, &settings, this);
+
+        // Clear the error buffer..
+        errout.str("");
+
+        checkOther.sizeofsizeof();
+
+        // Simplify token list..
+        tokenizer.simplifyTokenList();
+
         checkOther.warningRedundantCode();
         checkOther.checkZeroDivision();
         checkOther.checkMathFunctions();
@@ -2503,6 +2508,15 @@ private:
               "}\n");
         ASSERT_EQUALS("", errout.str());
     }
+
+    void sizeofsizeof()
+    {
+        check("void foo()\n"
+              "{\n"
+              "    int i = sizeof sizeof char;\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) Suspicios code 'sizeof sizeof ..', most likely there should only be one sizeof. The current code is equivalent with 'sizeof(size_t)'.\n", errout.str());
+    }
 };
 
 REGISTER_TEST(TestOther)