value flow: added bailout for conditional return/continue/break when number_of_if is bigger than 0

lib/valueflow.cpp

@@ -504,6 +504,16 @@ static void valueFlowAfterAssign(TokenList *tokenlist, ErrorLogger *errorLogger,
                             ++it;
                     }
                 }
+
+                // noreturn scopes..
+                if (number_of_if > 0 &&
+                    (Token::findmatch(start, "return|continue|break", end) ||
+                     (Token::Match(end,"} else {") && Token::findmatch(end, "return|continue|break", end->linkAt(2))))) {
+                    if (settings->debugwarnings)
+                        bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + ". noreturn conditional scope.");
+                    break;
+                }
+
                 if (Token::findmatch(start, "++|-- %varid%", end, varid) ||
                     Token::findmatch(start, "%varid% ++|--|=", end, varid)) {
                     if (number_of_if == 0 &&

test/testvalueflow.cpp

@@ -547,6 +547,14 @@ private:
                "}";
         ASSERT_EQUALS(false, testValueOfX(code, 5U, 1));
 
+        code = "void f(){\n"
+               "    int x = 0;\n"
+               "    if (a>=0) { x = getx(); }\n"
+               "    if (x==0) { return; }\n"
+               "    return 123 / x;\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfX(code, 5U, 0));
+
         // multivariables
         code = "void f(int a) {\n"
                "    int x = a;\n"