NSString stringWithFormat格式警告

Question

I am probably using a wrong symbol for the NSString type to be included in another string.

const char* error; //it's set, not nil
NSLog([NSString stringWithFormat : @"Problem with SQL statement in \n %@ \n %@",sqlQuery,[NSString stringWithUTF8String:error]]);

The expression works, but I am getting this warning:

Formatting string is not a string literal(potentially insecure)

Is there a way to get rid of the warnings?

Answer 1

According to NSLog implementation, the function expects a constant string or a format specifier string as it's first argument.

You need to use:

NSLog(@"Problem with SQL statement in [BSurfSpotDBOperations allSpots] \n %@ \n %@",sqlQuery,[NSString stringWithUTF8String:error]);

Answer 2

Format strings in NSLog() statements must be constant strings or there will be a warning. Re-write the code to make the format portion a string literal.

In general avoid complex compound statements. Temporary variables make the code more readable and potentially less buggy. The compiler is quite good at elimination temporaries at release compile-time.

Example:

const char* error; //it's set, not nil
NSString *errorString = [NSString stringWithUTF8String:error];
NSLog(@"Problem with SQL statement in [BSurfSpotDBOperations allSpots] \n %@ \n %@", sqlQuery, errorString);

Answer 3

stringWithFormat is unnecessary here since NSLog() gives you similar options. You could simply change it to this:

NSLog(@"Problem with ... \n %@ \n %@", sqlQuery,[NSString stringWithUTF8String:error]);

This will eliminate the warning since the NSLog knows it isn't going to run into a string literal it doesn't know what to do with, which is a security concern.

Answer 4

Try this method :

NSLog([@"Problem with SQL statement in [BSurfSpotDBOperations allSpots] \n %@ \n %@"
,sqlQuery,[NSString stringWithUTF8String:error]);

I think you can also translate [NSString stringWithUTF8String:error] by error

Think this can help you ;)