Fixed #608 (Tokenizer: simplifyKnownVariables doesn't handle 'while (--i)' correctly)

src/tokenize.cpp

@@ -2827,6 +2827,24 @@ bool Tokenizer::simplifyKnownVariables()
                             break;
                     }
 
+                    // Stop if something like 'while (--var)' is found
+                    if (tok3->str() == "while")
+                    {
+                        const Token *endpar = tok3->next()->link();
+                        bool bailout = false;
+                        for (const Token *tok4 = tok3; tok4 != endpar; tok4 = tok4->next())
+                        {
+                            if (Token::Match(tok4, "++|-- %varid%", varid) ||
+                                Token::Match(tok4, "%varid% ++|--", varid))
+                            {
+                                bailout = true;
+                                break;
+                            }
+                        }
+                        if (bailout)
+                            break;
+                    }
+
                     if (bailOutFromLoop)
                     {
                         // This could be a loop, skip it, but only if it doesn't contain

test/testtokenize.cpp

@@ -78,6 +78,7 @@ private:
         TEST_CASE(simplifyKnownVariables10);
         TEST_CASE(simplifyKnownVariables11);
         TEST_CASE(simplifyKnownVariables12);
+        TEST_CASE(simplifyKnownVariables13);
 
         TEST_CASE(match1);
 
@@ -873,6 +874,29 @@ private:
         ASSERT_EQUALS(" ENTER_NAMESPACE ( project_namespace ) const double pi = 3.14 ; int main ( ) { }", ostr.str());
     }
 
+    void simplifyKnownVariables13()
+    {
+        const char code[] = "void f()\n"
+                            "{\n"
+                            "    int i = 10;\n"
+                            "    while(--i) {}\n"
+                            "}\n";
+
+        // tokenize..
+        Tokenizer tokenizer;
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+
+        tokenizer.setVarId();
+        tokenizer.simplifyKnownVariables();
+
+        std::ostringstream ostr;
+        for (const Token *tok = tokenizer.tokens(); tok; tok = tok->next())
+            ostr << " " << tok->str();
+        ASSERT_EQUALS(" void f ( ) { int i ; i = 10 ; while ( -- i ) { } }", ostr.str());
+    }
+
+
     void match1()
     {
         // Match "%var% | %var%"