Dear Timur Tabi,
In message ed82fe3e0904081325s560fb99cg83b6aaa9176cd8db@mail.gmail.com you wrote:
I don't see what's wrong with that. The advantage is that the variable is close to where it's being used, so that you can see the context more easily.
Bear with an old man like me. I am used to the habit that variables get decleared at the begin of a block, not in the middle of it. When searching for the declaration of a variable, I find it a major PITA if I have to scan the whole source file instea dof just looking at the first few lines of a block.
I don't see what the value is of limiting the lifetime of the variable. The compiler isn't going to use that as a hint, anyway.
Not the compiler, but humans like me. I have just a small window of lines I can really focus on, and the smaller a block of code (including the needed variable declarations), the easier I get the impression I understand it.
It's just going to use this for syntax checking. If you define and initialize a variable at the top of the function, but don't use that variable until a hundred lines later, the compiler is going to initialize the variable when it's first used, not when the function is first entered. Chances are it's not even going to define stack space for it.
Keep in mind that we don't write the code for the compiler, but for the human being that comes after us and that has to maintain that code.
#ifdef CONFIG_COOL_FEATURE { u32 myvarrocks = foo * bar * bar;
gd->neato = myvarrocks} #endif
Is this an acceptable compromise?
This is what we do today, and I think it's ugly.
It is ugly, but much less ugly than variable declarations right in the middle of 200 lines of code.
Best regards,
Wolfgang Denk