DEBUG AND RELEASE MODE

[karmendra_js]

hello, I want to know what is the difference between debug mode and release mode. I started adn finished my project in release mode, how would it be different if it was done in debug mode. Thanks,

[kakan]

Hello. The differences I came to think about (there might be other deifferences as well) is: In the debug version, there is (of course) a lot of information that aids the debugger. There are no code optimisations in the debug build. Allocated memory is filled with nulls in debug mode. More, anyone?

[toxcct]

kakan is right, but to complete, just compare the sizes of your two generated (debug and release) exes... you'll see the difference !

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TOXCCT >>> GEII power
[toxcct][VisualCalc]

[David Crow]

In Debug mode, all local variables not explicitly initialized by the program are initialized with 0xCC.

karmendra_js wrote:

I started adn finished my project in release mode, how would it be different if it was done in debug mode.

This is backwards. You should develop and test it in Debug mode, and only when all of the bugs have been removed should you compile it in Release mode.

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"Take only what you need and leave the land as you found it." - Native American Proverb

[Chintoo723]

kakan wrote:

Allocated memory is filled with nulls in debug mode

whats the reason for this difference? thanks!

[Gary R Wheeler]

In debug mode, filling uninitialized memory with zero's makes it easier to see that your program has not initialized it.

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Software Zen: delete this;

[Gary R Wheeler]

In debug mode, two things happen. First, the compiler generates information about your program used by the debugger. The compiler also generates code to initialize memory to default values. Second, in debug mode you run your programmer under the debugger. The debugger lets you step through your code, examine data as the program executes, set breakpoints, and perform other operations. The purpose of the debugger is to let you run your program in a controlled fashion so that you can see what it is doing as it runs. In release mode, the compiler doesn't initialize memory for you; it assumes your program will initialize what it needs. As a rule, in release mode the compiler will also 'optimize' your code. In simplest terms, the compiler generates machine code that runs as fast as possible. The machine code in this case looks different from the debug version, since the compiler can rearrange operations in order to improve efficiency. As someone else has mentioned, you really want to run your program in debug mode first. This lets you get things working in a controlled environment. After it looks like things are working correctly in debug mode, rebuild the program in release mode, and test it again. There are subtle differences between debug and release. The article Debugging Release Mode Problems[^] has more information.

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Software Zen: delete this;

[kakan]

See Gary R. Wheeler's answer, above. But this difference in behaviour is a very common source of problems in release mode builds.