stl: removed false positives for STL buffer overruns. Bailing out when it can't be checked if the index is ok or not. (#285)

src/checkstl.cpp

@@ -86,59 +86,45 @@ void CheckStl::stlOutOfBounds()
         if (!Token::simpleMatch(tok, "for ("))
             continue;
 
-
+        unsigned int indent = 0;
-        int indent = 1;
+        for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
-        tok = tok->tokAt(2);
-        const Token *num = 0;
-        const Token *var = 0;
-        while (tok)
         {
 
-            if (tok->str() == "(")
+            if (tok2->str() == "(")
                 ++indent;
-            if (tok->str() == ")")
+
+            else if (tok2->str() == ")")
             {
-                --indent;
                 if (indent == 0)
                     break;
-            }
-
-            if (Token::Match(tok, "; %var% <= %var% . size ( ) ;"))
-            {
-                num = tok->tokAt(1);
-                var = tok->tokAt(3);
-            }
-
-            tok = tok->next();
-        }
-
-        if (!tok)
-            return;
-
-        tok = tok->next();
-        if (!num || tok->str() != "{")
-            continue;
-
-        std::string pattern = var->str() + " [ " + num->str() + " ]";
-        while (tok)
-        {
-
-            if (tok->str() == "{")
-                ++indent;
-            if (tok->str() == "}")
-            {
                 --indent;
-                if (indent == 0)
-                    break;
             }
 
-
+            if (Token::Match(tok2, "; %var% <= %var% . size ( ) ;"))
-            if (Token::Match(tok, pattern.c_str()))
             {
-                stlOutOfBoundsError(tok, num->str(), var->str());
+                indent = 0;
+                const std::string num(tok2->strAt(1));
+                const std::string varname(tok2->strAt(3));
+                for (const Token *tok3 = tok2->tokAt(8); tok3; tok3 = tok3->next())
+                {
+                    if (tok3->str() == "{")
+                        ++indent;
+                    else if (tok3->str() == "}")
+                    {
+                        if (indent == 0)
+                            break;
+                        --indent;
+                    }
+                    else if (tok3->str() == varname)
+                    {
+                        if (Token::simpleMatch(tok3->next(), ". size ( )"))
+                            break;
+                        else if (Token::simpleMatch(tok3->next(), ("[ " + num + " ]").c_str()))
+                            stlOutOfBoundsError(tok3, num, varname);
+                    }
+                }
+                break;
             }
-
-            tok = tok->next();
         }
     }
 }

test/teststl.cpp

@@ -188,7 +188,7 @@ private:
                   "        }\n"
                   "    }\n"
                   "}\n");
-            TODO_ASSERT_EQUALS(std::string(""), errout.str());
+            ASSERT_EQUALS(std::string(""), errout.str());
         }
     }