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Expressions not always updating [message #821578]

Thu, 15 March 2012 10:55

Eclipse User

I have several Watch Expressions that I am following through a debug session. However, I noticed that some of the expressions were not updating as they should have in the code. I confirmed this by doing a command line gdb session (which is the same debugger that I am using in CDT: gdb/mi).

All I was following were simple indices in nested for loops, just like below:

for ( int i = 0; i<num_rows; i++ )
{
<code>
for ( int j = 0; j < 4; j++ )
{
<code>
}
}

"i" and "j" were not updating properly in the Expressions view.

I am running eclipse Galileo with CDT Version 6.0.0.200909110608 in a Linux environment. Any idea why the above occurs? Does a later version of CDT solve the problem?

Re: Expressions not always updating [message #822139 is a reply to message #821578]

Fri, 16 March 2012 04:07

Eclipse User

I did not experience the problems you mentioned with Galileo. Do you have any compiler optimization turned on?

Re: Expressions not always updating [message #822498 is a reply to message #822139]

Fri, 16 March 2012 14:18

Eclipse User

Yes, there are some optimizer options set for the gcc compiler in the Makefile.

Re: Expressions not always updating [message #825860 is a reply to message #822498]

Wed, 21 March 2012 06:50

Eclipse User

Aero Engineer wrote on Fri, 16 March 2012 19:18

Yes, there are some optimizer options set for the gcc compiler in the Makefile.

If optimization is turned you will get funny results during debug. Because the compiler might rearrange your code and omit some variables. I guess the second loop in your example with constant length of 4 will be completely replaced in the optimized code.

Re: Expressions not always updating [message #836613 is a reply to message #825860]

Wed, 04 April 2012 13:52

Eclipse User

Thanks for your answer. I just now got back to working on this issue.

Re: Expressions not always updating [message #836829 is a reply to message #836613]

Wed, 04 April 2012 20:40

Eclipse User