Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

strange struct declaration

Posted on 1999-01-19
5
Medium Priority
?
243 Views
Last Modified: 2010-04-20
I recently found the following declaration in a program I'm studying:

static struct symbol_table my_symtab = {
         #include <linux/symtab_begin.h>
         X(printk),
        X(vmalloc),
        X(vfree),
        X(kerneld_send),
        X(current_set),
        X(sys_call_table),
        X(register_symtab_from),
        #include <linux/symtab_end.h>
};



I know the symbol_table struct is defined in module.h; but its contents seem to bear no resemblance to the above. Why does the declaration begin and end with the preprocessor instructions, and what exactly do symtab_begin.h and symtab_end.h do? (They're not on my system - Linux 2.0.0 slakware - at all.) Also, what does the X refer to? Is it some obscure preprocessor instruction? (It's not mentioned in Kernighan and Ritchie's book.)

Thanks for any help,

David
0
Comment
Question by:sevrin
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
5 Comments
 
LVL 84

Expert Comment

by:ozo
ID: 1639176
Is X defined in linux/symtab_begin.h?
0
 
LVL 10

Accepted Solution

by:
rbr earned 300 total points
ID: 1639177
Serach for a define X in your header files. The X must be a macro which is replaced by compile time with the structure component.
0
 
LVL 10

Expert Comment

by:rbr
ID: 1639178
I found the define X in the
symtab_begin.h
#define X(sym) { _basic_version(sym) }

0
 

Author Comment

by:sevrin
ID: 1639179
Ah, a macro. As I say, I don't have symtab_begin.h or symtab_end.h, so it was impossible for me to find out.

Thanks,

David
0
 
LVL 10

Expert Comment

by:rbr
ID: 1639180
To ozo: Sorry I answered the question at the same time so I didn't see your comment.
0

Featured Post

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

SSH (Secure Shell) - Tips and Tricks As you all know SSH(Secure Shell) is a network protocol, which we use to access/transfer files securely between two networked devices. SSH was actually designed as a replacement for insecure protocols that sen…
I. Introduction There's an interesting discussion going on now in an Experts Exchange Group — Attachments with no extension (http://www.experts-exchange.com/discussions/210281/Attachments-with-no-extension.html). This reminded me of questions tha…
Learn how to find files with the shell using the find and locate commands. Use locate to find a needle in a haystack.: With locate, check if the file still exists.: Use find to get the actual location of the file.:
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
Suggested Courses

636 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question