Reply to: In C++ what type of header file changes would not cause either a linkage or run time

[expat]

Some of us can remember how overlay linkers work too... not something that's come in handy over the last 15 years though...

God yes: I remember having to decide which modules were dependent so that you always had the bits you needed loaded....

where's that dinosaur smiley?

[Churchill]

Some of us can remember how overlay linkers work too... not something that's come in handy over the last 15 years though...

Bring back "Turbo Pascal" and "Turbo C"!!!

Btw, whatever happened to Philipe Kahn?

[d000hg]

Testing someone has real deep knowledge of particular skills isn't bad. Sometimes you want a real, full-on expert who knows the language/technologies inside out, rather than someone who has picked up enough to get by.

That said, there are many dumb interview questions out there; this may be one of them. Although, knowing how DLLs and linkers work isn't that esoteric, anyone who learned programming before the days of fancy IDEs should know this kind of subject and maybe that's the kind of person they want - a grizzled veteran

[BrilloPad]

Ooh cool. I have seen those threads where people look in and post things like

<popcorn in the microwave, six pack in the fridge>

but never thought I would be "involved" in one.


My life gets a little bit richer.

BrilloPad - "types like that", love the passive aggressive language. Made I larf.

I am pleased to have helped you along the way to true cuk enlightenment

BTW did I tell you about the really clever c++ coder who came from a pharacutical to the bank I worked at(TMI)? He thought that, because he was paid mnore he would get more complex coding to do and would be pushed more intellectually!!!

The only push he got was from an aggressive trader who asked why his delta was wrong and the coder had to explain to the trader that he was a numpty......

[lightng]

Well thats another two minutes of my life I'll never get back. I'm off to do something much more interesting like paint a new sleeper for my z-gauge railway zzzZZZZ.

[suityou01]

Because I'm a professional and know what I'm doing?



Actually he's changing the IMPLEMENTATION and PROTOTYPE (see I can use caps too), but asking what he can get away with in terms of not also changing the caller to match.

And no I don't work in a bank, and yes I am underpaid.

To be fair, this isn't proper programming, or programming at all. It's arsing about with often deficient tools and third party libraries that leads to having to know this sort of stuff.

No way you could have got that from the OP. Bored now.

[VectraMan]

How did you get that from what he said. Need error outputs.

Because I'm a professional and know what I'm doing?

Of course if you change the function PROTOTYPE, the IMPLEMENTATION needs to change.

Actually he's changing the IMPLEMENTATION and PROTOTYPE (see I can use caps too), but asking what he can get away with in terms of not also changing the caller to match.

And no I don't work in a bank, and yes I am underpaid.

To be fair, this isn't proper programming, or programming at all. It's arsing about with often deficient tools and third party libraries that leads to having to know this sort of stuff.

[suityou01]

No he works in a bank. And its types like that which makes banks so s**t and lose loads of money.....

Ooh cool. I have seen those threads where people look in and post things like

<popcorn in the microwave, six pack in the fridge>

but never thought I would be "involved" in one.


My life gets a little bit richer.

BrilloPad - "types like that", love the passive aggressive language. Made I larf.

[BrilloPad]

Me understand programming plenty good!!!

How did you get that from what he said. Need error outputs.

Of course if you change the function PROTOTYPE, the IMPLEMENTATION needs to change. FFS. Nothing to see here.

Proper programming indeed. Are you always this quick off the mark?

No he works in a bank. And its types like that which makes banks so s**t and lose loads of money.....

[expat]

In C++ what type of .dll header file changes would NOT cause either a linkage or run time error with any other .dll which is dependent on it ?

I'm thinking of non-static stand alone functions in the header file or simple non-static data variables e.g.

.h
.....
void printMe(int x);
int x;


Am I right or do you disagree ? I belive changes to the header file including changing the signature of member functions in a class whether they be public, private or protected is going to break any .dll dependancies....

It certainly should.

[suityou01]

LOL at all the feeble minded .NETers, SQLers and HTMLers struggling to understand real programming.

It's the signature that's going to cause you problems; i.e. changing the name or changing the parameter types, changing something to virtual that wasn't before. And for that matter, you're generally okay adding non-virtual or static functions but adding virtual functions, even to an interface won't be a DLL load error but will more than likely result in you calling function A and ending up in function B.

I do this all the time as I have one project with an EXE and lots of DLLs, and I save myself build time by just building the DLL that I'm working on. I usually know when I need to build the whole thing, but do get caught out from time to time.

Of course I'd never release anything that wasn't a full clean build.

Me understand programming plenty good!!!

How did you get that from what he said. Need error outputs.

Of course if you change the function PROTOTYPE, the IMPLEMENTATION needs to change. FFS. Nothing to see here.

Proper programming indeed. Are you always this quick off the mark?

[BrilloPad]

LOL at all the feeble minded .NETers, SQLers and HTMLers struggling to understand real programming.

It's the signature that's going to cause you problems; i.e. changing the name or changing the parameter types, changing something to virtual that wasn't before. And for that matter, you're generally okay adding non-virtual or static functions but adding virtual functions, even to an interface won't be a DLL load error but will more than likely result in you calling function A and ending up in function B.

I do this all the time as I have one project with an EXE and lots of DLLs, and I save myself build time by just building the DLL that I'm working on. I usually know when I need to build the whole thing, but do get caught out from time to time.

Of course I'd never release anything that wasn't a full clean build.

Do you work in a bank?

[VectraMan]

LOL at all the feeble minded .NETers, SQLers and HTMLers struggling to understand real programming.

It's the signature that's going to cause you problems; i.e. changing the name or changing the parameter types, changing something to virtual that wasn't before. And for that matter, you're generally okay adding non-virtual or static functions but adding virtual functions, even to an interface won't be a DLL load error but will more than likely result in you calling function A and ending up in function B.

I do this all the time as I have one project with an EXE and lots of DLLs, and I save myself build time by just building the DLL that I'm working on. I usually know when I need to build the whole thing, but do get caught out from time to time.

Of course I'd never release anything that wasn't a full clean build.

[suityou01]

After 22 years in the city this post sums it up! The number of times I am asked stupid stuff at interview that can be googled.

Blaster Bates for PM. Well, head of RBS anyway......

Had that lots. What do you do when you get THAT kind of interview, with some self important knob asking you stuff that you would only know if you had cribbed it from the same textbook?

I must admit I get slightly fed up, and ask why anyone would be expected to know the answer.

"Surely compiler switches for 64 bit risk processor optimisation are common knowledge?"

[BrilloPad]

sounds like an anal interview question that in no way demonstrates how good you are at the job.

Don't even try to play the game, it is designed to make you have a sleepless night wondering why you didn't know the answer.

We wouldn't put anything even onto a test system without recompiling everything that had a dependency. But there are brainless idiots in City banks who pride themselves on putting everyone's bank account at risk just to show how bloody clever they are.

No wonder they're all bankrupt.

I used to think to myself, hey these guys make pots of money so maybe I am stupid. But I've now changed my mind.

After 22 years in the city this post sums it up! The number of times I am asked stupid stuff at interview that can be googled.

Blaster Bates for PM. Well, head of RBS anyway......