AST: refactored CheckSizeof::sizeofCalculation()

danmar · danmar · commit eb2ea1c28f76 · 2013-12-25T12:35:41.000+01:00
diff --git a/lib/checksizeof.cpp b/lib/checksizeof.cpp
@@ -22,6 +22,7 @@
 #include "symboldatabase.h"
 #include <algorithm>
 #include <cctype>
+#include <stack>
 //---------------------------------------------------------------------------
 
 // Register this check class (by creating a static instance of it)
@@ -219,23 +220,50 @@ void CheckSizeof::sizeofsizeofError(const Token *tok)
 
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------
+static bool isCalculation(const Token *op)
+{
+    if (!op)
+        return false;
+
+    if (!Token::Match(op, "%cop%|++|--"))
+        return false;
+
+    if (Token::Match(op, "*|&")) {
+        // dereference or address-of?
+        if (!op->astOperand2())
+            return false;
+
+        // type specification?
+        std::stack<const Token *> operands;
+        operands.push(op);
+        while (!operands.empty()) {
+            const Token *item = operands.top();
+            operands.pop();
+            if (item->isNumber() || item->varId() > 0)
+                return true;
+            if (item->astOperand1())
+                operands.push(item->astOperand1());
+            if (item->astOperand2())
+                operands.push(item->astOperand2());
+        }
+
+        // type specification => return false
+        return false;
+    }
+
+    return true;
+}
+
 void CheckSizeof::sizeofCalculation()
 {
     if (!_settings->isEnabled("warning"))
         return;
 
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::simpleMatch(tok, "sizeof (")) {
-            const Token* const end = tok->linkAt(1);
-            for (const Token *tok2 = tok->tokAt(2); tok2 != end; tok2 = tok2->next()) {
-                if (tok2->isConstOp() && (!tok2->isExpandedMacro() || _settings->inconclusive) && !Token::Match(tok2, ">|<|&") && (Token::Match(tok2->previous(), "%var%") || tok2->str() != "*")) {
-                    if (!(Token::Match(tok2->previous(), "%type%") || Token::Match(tok2->next(), "%type%"))) {
-                        sizeofCalculationError(tok2, tok2->isExpandedMacro());
-                        break;
-                    }
-                } else if (tok2->type() == Token::eIncDecOp)
-                    sizeofCalculationError(tok2, tok2->isExpandedMacro());
-            }
+            const Token *argument = tok->next()->astOperand2();
+            if (isCalculation(argument) && (!argument->isExpandedMacro() || _settings->inconclusive))
+                sizeofCalculationError(argument, argument->isExpandedMacro());
         }
     }
 }
