C / C++ / MFC

13-Jul-08 0:31

Hello everyone,

For the following code, I can not set breakpoint in release mode, but the same command in WinDbg works fine in debug mode. Anything wrong?

Here is my Windbg command and output in release mode and source codes. I have tested in release mode breakpoint at foo does not take effect, but in debug mode it takes effect.

0:000> bp foo
Bp expression 'foo' could not be resolved, adding deferred bp
0:000> bp main
0:000> bl
 0 eu                      0001 (0001) (foo)
 1 e 00000001`40001000     0001 (0001)  0:**** Test64bitDebug!main

int foo (int a, int b)
{
 return a+b;
}
int main()
{
 int a1 = 100;
 int b1 = a1 + 100;
 a1 = foo (a1, b1);
 return 0;
}

thanks in advance,
George

Ștefan-Mihai MOGA13-Jul-08 0:56

13-Jul-08 0:56

Hi George,

could you please tell us why you need breakpoints for release mode applications? You also have the debug mode to debug your application. Don't you think is enought?

Best regards,
Mihai Moga

George_George13-Jul-08 2:01

13-Jul-08 2:01

Thanks Mihai,

Because in real test environment, we need to work with release mode code, not debug mode code. Anyway, any ideas to my original question?

regards,
George

Ștefan-Mihai MOGA13-Jul-08 4:17

13-Jul-08 4:17

Hi George,

I do not have an answer to your original question, but did you read Keith Rule's Debugging Release Mode Problems[^] article?

Best regards,
Mihai Moga

George_George14-Jul-08 22:19

14-Jul-08 22:19

Thanks Mihai,

I read through the article, looks great! A few more comments,

1. We could only use VERIFY in MFC based application, corrrect?

2. In the article it is mentioned "In my personal experience, I've rarely seen a problem that really was bad code generation. My experience with VC++ 6.0 has been that the compiler occasionally asserts while generating code (especially when using templates), but I've not experienced any problem with my code associated with bad code generation. Installing service release 3 seems to have taken care of all the code generation asserts that I've seen in previous versions."

What means "asserts" here?

regards,
George

Ștefan-Mihai MOGA15-Jul-08 9:12

15-Jul-08 9:12

Hi George,

to answer to your questions I gently ask you to read couple more articles:
a) Rob Manderson's Assert is your friend[^]
b) srana's MFC Windows Coding Guidelines[^]

Best regards,
Mihai Moga

P.S. YES, you should use only

VERIFY

to ensure that your code goes to release version of your application; use

ASSERT

only for definitions/expressions/assertions.

George_George16-Jul-08 19:11

16-Jul-08 19:11

Thanks Mihai,

I have read through the article. And I want to confirm with you that VERIFY could only be used with MFC application, correct?

regards,
George

Ștefan-Mihai MOGA17-Jul-08 8:30

17-Jul-08 8:30

Yes George, you are right.

Best regards,
Mihai Moga

George_George17-Jul-08 21:01

17-Jul-08 21:01

Great, thanks Mihai!

Any comments to my question item 2 here?

http://www.codeproject.com/script/Forums/View.aspx?fid=1647&msg=2638078[^]

regards,
George

Stephen Hewitt13-Jul-08 15:11

Stephen Hewitt

13-Jul-08 15:11

It's not enough. Although you should debug in the debug build most times there are classes of bugs that only manifest in release builds.

Steve

George_George13-Jul-08 19:47

13-Jul-08 19:47

Thanks Steve,

Any comments to my original question? Smile | :)

regards,
George

followait13-Jul-08 3:08

followait

13-Jul-08 3:08

I think, in release mode, the code may be optimized, so the binary codes may not map to the source code, so it doesn't support break point in source code.

system

George_George13-Jul-08 19:45

13-Jul-08 19:45

Thanks followait!

Do you have any ideas to check whether a function is optimized out or not?

regards,
George

sudhir_Kumar13-Jul-08 20:02

sudhir_Kumar

13-Jul-08 20:02

just do some settings -

Settings->Link - Check - Generate Debug Info

Settings->C/C++ - Select Disable/Debug in Optimazations Combo
- Check Generate Browse Info
- Select "Program Database" in Debug Info Combo

Complile the application

You can debug the release mode.

-@SuDhIrKuMaR@-

George_George13-Jul-08 21:23

13-Jul-08 21:23

Thanks sudhir_Kumar,

What are the so-called debug information contains? I think symbols are in PDB file and what are else debug info for release binary code?

regards,
George

Stephen Hewitt13-Jul-08 21:31

Stephen Hewitt

13-Jul-08 21:31

The debug information is what's contained in PDB files. It contains a myriad of information including:

Mappings from addresses to source files and line numbers.
The layout of structures and classes.
Type information.
Stack layout so local variables can be examined.

Basically all the information the debugger needs.

Steve

George_George13-Jul-08 21:34

13-Jul-08 21:34

Thanks Steve,

Even if I do not turn on the debug information, there is still the PDB file. You mean if I do not turn on the option, PDB will not be generated? Or?

regards,
George

Stephen Hewitt13-Jul-08 21:38

Stephen Hewitt

13-Jul-08 21:38

The PDB file is only generated if the options I pointed out are turned on. A PDB file is nothing but a container for the debug information. When you ship an application you should keep the PDB files, generally in a Symbol Server[^].

Steve

George_George13-Jul-08 21:49