Fixed false negative #5815

lib/checksizeof.cpp

@@ -251,7 +251,7 @@ void CheckSizeof::sizeofCalculation()
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::simpleMatch(tok, "sizeof (")) {
             const Token *argument = tok->next()->astOperand2();
-            if (argument && argument->isCalculation() && (!argument->isExpandedMacro() || printInconclusive))
+            if (argument && argument->isCalculation(true) && (!argument->isExpandedMacro() || printInconclusive))
                 sizeofCalculationError(argument, argument->isExpandedMacro());
         }
     }

lib/token.cpp

@@ -1136,8 +1136,19 @@ void Token::astOperand2(Token *tok)
     _astOperand2 = tok;
 }
 
-bool Token::isCalculation() const
+bool Token::isCalculation(bool goDownwards) const
 {
+    if (goDownwards && Token::Match(this, "[|(|,")) {
+        bool ret = false;
+        if (this->astOperand1())
+            ret = this->astOperand1()->isCalculation(true);
+        if (ret)
+            return true;
+        if (this->astOperand2())
+            ret = this->astOperand2()->isCalculation(true);
+        return ret;
+
+    }
     if (!Token::Match(this, "%cop%|++|--"))
         return false;
 

lib/token.h

@@ -872,9 +872,10 @@ public:
      * For '*' and '&' tokens it is looked up if this is a
      * dereference or address-of. A dereference or address-of is not
      * counted as a calculation.
+     * @param goDownwards the function will look for calculations in all children of the tree
      * @return returns true if current token is a calculation
      */
-    bool isCalculation() const;
+    bool isCalculation(bool goDownwards = false) const;
 
     void clearAst() {
         _astOperand1 = _astOperand2 = _astParent = NULL;

test/testsizeof.cpp

@@ -108,6 +108,18 @@ private:
 
         check("sizeof(--foo)");
         ASSERT_EQUALS("[test.cpp:1]: (warning) Found calculation inside sizeof().\n", errout.str());
+
+        check("sizeof(bar(1, 2, --foo, 3, 4))");
+        ASSERT_EQUALS("[test.cpp:1]: (warning) Found calculation inside sizeof().\n", errout.str());
+
+        check("sizeof( int32_t[ i++ ] );");
+        ASSERT_EQUALS("[test.cpp:1]: (warning) Found calculation inside sizeof().\n", errout.str());
+
+        check("sizeof(a[b + 2])");
+        ASSERT_EQUALS("[test.cpp:1]: (warning) Found calculation inside sizeof().\n", errout.str());
+
+        check("sizeof((2 + a)[b])");
+        ASSERT_EQUALS("[test.cpp:1]: (warning) Found calculation inside sizeof().\n", errout.str());
     }
 
     void sizeofForArrayParameter() {