Thread: implicit declaration

I have defined two functions:
extract_ip_patterns and extract_op_patterns.
They are almost the same and used in the same main program. But there is a warning message about extract_op_patterns:

implicit declaration of function 'extract_op_patterns'

whereas there is no such warning message about extract_ip_patterns. And I found that if I use them seperately, there is no warning message. Can anyone help me to solve this problem?

I'm sorry that I can't understand. Can you explain it in more details?

Quzah is showing you that you need to declare the function before you use it... I guess you're trying to use 'extract_op_patterns' before even you declared it.

I think I have declared it. As I mentioned, there is a similar function called 'extract_ip_patterns' which is used in the same program.
But, there is no problem on using this function. And, I have used the same way to use 'extract_op_patterns'.
However, it doesn't work. Maybe the problem is easier to be found with my code posted.

I think you have not included the function body of the function,
extract_ip_patterns. If this is in another source file, you have to compile it like this. If you are using GCC

Code:

       gcc extract_ip_patterns.c svm-train3.c

extrace_ip_patterns.c is the source file containing the funtion body of the extract_ip_patterns.
If you have already done this check the spelling.

This code compiles(even without a warning) and works fine. I used GCC.

Code:

int main( void )
{
    return foo( );
}

int foo( void ) { return 0; }