AssignIf: Check into scopes recursively

lib/checkassignif.cpp

@@ -51,30 +51,51 @@ void CheckAssignIf::assignIf()
             if (num < 0)
                 continue;
 
-            for (const Token *tok2 = tok->tokAt(4); tok2; tok2 = tok2->next()) {
+            assignIfParseScope(tok, tok->tokAt(4), varid, bitop, num);
-                if (tok2->str() == "(" || tok2->str() == "}" || tok2->str() == "=")
+        }
-                    break;
+    }
-                if (Token::Match(tok2, "if|while|for (")) {
+}
+
+/** parse scopes recursively */
+bool CheckAssignIf::assignIfParseScope(const Token * const assignTok,
+                                       const Token * const startTok,
+                                       const unsigned int varid,
+                                       const char bitop,
+                                       const MathLib::bigint num)
+{
+    for (const Token *tok2 = startTok; tok2; tok2 = tok2->next()) {
+        if (Token::Match(tok2, "[(,] &| %varid% [,)]"))
+            return true;
+        if (tok2->str() == "}")
+            return false;
+        if (Token::Match(tok2, "if (")) {
             // parse condition
             const Token * const end = tok2->next()->link();
             for (; tok2 != end; tok2 = tok2->next()) {
-                        if (Token::Match(tok2, "[(,] &| %varid% [,)]", varid))
+                if (Token::Match(tok2, "[(,] &| %varid% [,)]", varid)) {
-                            break;
+                    return true;
+                }
                 if (Token::Match(tok2,"&&|%oror%|( %varid% %any% %num% &&|%oror%|)", varid)) {
                     const Token *vartok = tok2->next();
                     const std::string& op(vartok->strAt(1));
                     const MathLib::bigint num2 = MathLib::toLongNumber(vartok->strAt(2));
                     const std::string condition(vartok->str() + op + vartok->strAt(2));
                     if (op == "==" && (num & num2) != ((bitop=='&') ? num2 : num))
-                                assignIfError(tok, tok2, condition, false);
+                        assignIfError(assignTok, tok2, condition, false);
                     else if (op == "!=" && (num & num2) != ((bitop=='&') ? num2 : num))
-                                assignIfError(tok, tok2, condition, true);
+                        assignIfError(assignTok, tok2, condition, true);
-                        }
-                    }
                 }
             }
+
+            bool ret1 = assignIfParseScope(assignTok, end->tokAt(2), varid, bitop, num);
+            bool ret2 = false;
+            if (Token::simpleMatch(end->next()->link(), "} else {"))
+                ret2 = assignIfParseScope(assignTok, end->next()->link()->tokAt(3), varid, bitop, num);
+            if (ret1 || ret2)
+                return true;
         }
     }
+    return false;
 }
 
 void CheckAssignIf::assignIfError(const Token *tok1, const Token *tok2, const std::string &condition, bool result)

lib/checkassignif.h

@@ -55,6 +55,13 @@ public:
     /** mismatching assignment / comparison */
     void assignIf();
 
+    /** parse scopes recursively */
+    bool assignIfParseScope(const Token * const assignTok,
+                            const Token * const startTok,
+                            const unsigned int varid,
+                            const char bitop,
+                            const MathLib::bigint num);
+
     /** mismatching lhs and rhs in comparison */
     void comparison();
 

test/testassignif.cpp

@@ -105,6 +105,14 @@ private:
               "    if (setvalue(&y) && y != 8);\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        // recursive checking into scopes
+        check("void f(int x) {\n"
+              "    int y = x & 7;\n"
+              "    if (z) y=0;\n"
+              "    else if (y==8);\n" // always false
+              "}");
+        ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false.\n", errout.str());
     }
 
     void compare() {