Let me tell you a story about a guy named Jed...
A long long time ago (pre-ANSI C), in a galaxy far far away I had worked for a company that had to develop internal "C" coding standards and "Jed" worked on one aspect of the standard while I worked on another. We would hold weekly meetings to reconcile our differences. In attendance, we had other professionals for simple sanity checking and to gain insights from different points of view.
Chris was one of our attendees and was a very experienced software veteran who had plenty of code in various satellite systems orbiting our planet today. By then, Chris was in upper management and graced us with his wisdom when he could.
Well during one of our weekly meetings, "Jed" and I got into a simple disagreement on a Rule about header files. We were at an impasse, so we waited for Chris to arrive and have him make the final decision: about five of us professional engineers were in the room.
When Chris arrived, he heard the arguments, and quickly announced that I was right. (Hence, Jed was wrong).
Well, Jed freaked out and wanted to take the guy outside and teach him a lesson! ... Jed was red-faced, quickly stood up, even took a step towards Chris, and said "Chris, lets just step outside and settle this! I am right and you don't know what you're talking about!" etc etc.
The other attendees and I were duly impressed over Jed's technique of handling technical disagreements. Especially with upper management.
Instead of Jed trying to learn that he *might* be wrong, Jed leaped into the confrontation method of getting his way. Bullies do this because they lack the brain-power to reason through a disagreement. It is a childish trait.
Children are at a huge disadvantage when arguing with "an adult" (or somebody who is much smarter than they are) and they will become very frustrated over their strong desire to assert themselves and their inability to win the mental sparring. They will get physical and/or verbally abusive. Some people out grow this, and some don't.
I think Jed showed his 'abilities' quite well. I find that this is true with so many people on so many subjects. I've seen this behavior many times over. I've seen it here on this forum.
When an "Original Poster", asks a question and people try to answer it (after much refinement of the OP's question) you get these side-bar posts where somebody will start attacking another poster's efforts. And I mean 'attack' and not augment or refine.
I don't have a problem with correcting or clarifying others, or even the occasional sprinkling of sarcasm, but when it is ALWAYS devolves into some vindictive vitriol between a brisling poster and the rest of 'us,' I wonder if it is out of ignorance, malice, or some twisted form of self-entertainment. All three of which are adolescent behaviors. (en.wikipedia.org/.../Adolescence)
Since the regular players here are detail oriented and thus they are savvy enough to know who I'm talking about, I don't think I have to name names.
He is critical enough to figure it out himself, so I would expect that the offender would read this and ask himself if he is demonstrating Ignorance, Malice, Entertainment, or is he being an adult and providing a constructive post before he does so.
And, I hope his "Mea Clupea" (en.wikipedia.org/.../Mea_culpa) will be a silent one, because I'm kind of tired of reading his Hostile Postings (HP).
</rant> --Cpt. Vince Foster 2nd Cannon Place Fort Marcy Park, VA
There are postings that are hostile and/or argumentative (I have part of the guilt here) however I, for one do not see the need to hide behind a monniker. I know I should just ignore the smoked sardine and the bratwurst but it is darn tough when they attack my abilities/professionalism. if they would move ther personal attacks to e-mail, this would be a much more peaceful place. comments like But - they won't study program design, they'll only read a 'C' book as a last resort, they learn by trying things to see if they appear to work, if they do - fine, job done. The attitude is so different than the one they take with hardware design, its weird.
So - you're not alone. But you won't be missed by those who have to pick up the pieces when you're gone. have no merit in the forum and should be relegated to e-mail I post under my REAL name and if anyone want to write me directly go to http://www.8052.com and use the e-mail gateway there.
Erik Malund
I know I should just ignore the smoked sardine and the bratwurst but it is darn tough when they attack my abilities/professionalism.
You can't expect to post whatever you like in a public forum and have it quietly ignored.
if they would move ther personal attacks to e-mail, this would be a much more peaceful place.
Why do you view any disagreement as a 'personal attack'? If you're prepared to expose yourself in public you really must expect responses in public.
comments like have no merit in the forum and should be relegated to e-mail
have no merit in the forum and should be relegated to e-mail
Based on what you post that quote seems an accurate reflection of your working practices. Have you ever read the 'C' standard? Would you use a chip without reading the datasheet?
you conveniently ignore that while "keil C" has a variable named BIT, you will not find that in the "ISO (formerly ANSI) Standard 'C'"
How do you reconcile the fact that C51 is an ANSI/ISO 'C' compiler with the existence of 'bit', I wonder?
well, I asked, why do you not answer instead of 'wonder"
You didn't ask anything, you made a statement to which I responded with a question. In any case, given that you treat any suggestion that you have not read the standard as a "baseless accusation" then I'm sure you'll feel insulted if I suggest that you might not know the answer to my question.
Do you still claim to have read the ISO 'C' standard?
how can this be portable without preprocessor directives #if COMPILER == C51 ....
It isn't portable. Wrapping code in preprocessor directives doesn't make it portable - in fact, it makes it clear that it is non-portable.
NOTE: it is, of course, possible to just use the OR and ignore the efficiency, but what if the C51 project is time critical
I'd be unlikely to have designed my way into a situation where a bit operation rather than a byte operation would make the difference between project success and project failure. Perhaps you write the code, compile and count the clock cycles before you select the processor and oscillator?
and the ACME project is not because it runs on a much faster processor
Ah, glad to see you agree with me. Use a faster processor.
If the above is not "to your liking" come out of your hole and state what I suspect is your position that you do not give a hoot about efficiency.
I care about efficiency where efficiency is the most important factor. With sensible design, however, it rarely is.
In short "Wrapping code in preprocessor directives doesn't make it portable - in fact, it makes it clear that it is non-portable" is contradicted by your own statements.
Really? Which ones?
#if C51 typedef bit Flag; #else typedef unsigned char Flag; #endif
Rob, according to whoever hides behind "Jack Sprat", you are wrong, I quote: "Wrapping code in preprocessor directives doesn't make it portable - in fact, it makes it clear that it is non-portable."
evidently you are supposed to make your code portable without using "preprocessor directives"
Erik
Alas, in the real world, that is not always an option. Processors for embedded systems rarely get chosen for their ability to run 'portable' (and hence larger, slower) code - they get chosen for their ability to 'barely run the application for the lowest cost' - in this case - optimising for every last clock cycle can become an issue, especially when feature creep sets in.
Well taken to extremes, that is sheer nonsense; but I do not think (or hope) this is what is being said.
I have plenty of code that runs on different cores where the only difference is a single 'processor/core specific' header file.
At the very least, typedefs that provide specific width variables (e.g., 8, 16, 32) is nothing short of essential.
a) "I care about efficiency"
Really? Which ones? a) above for example.
I care about efficiency where efficiency is the most important factor. With sensible design, however, it rarely is. translated "if cost is an issue, do not involve the person hiding behind "Jack Sprat", he cares more about his fanciful ideas"
I'd be unlikely to have designed my way into a situation where a bit operation rather than a byte operation would make the difference between project success and project failure. so would I. Confound it, can you not understand what an example is, www.merriam-webster.com/.../example see 3)
* Jack must agree with me that bit fields are not really a solid part of the C standard.
If Jack did agree with that, I'd have to disagree with Jack. Until then I'll just disagree with you.
Bit fields are quite a solid part of the C standard. Their only weak aspect lies in many people's idea of what they should be used for. Suffice it to say that, like pretty much all of C's data structures, they're intended for internal data of a C program, but not for its external interfaces.
compilers seem to have artistic freedom when dealing with them which can yield more or less efficient code (packing of structures...).
You have that backwards. Compilers have been granted all that freedom intentionally, to allow them to generate more efficient code. If you find inefficiency, blame it on the platform or the compiler.
If Jack did agree with that, I'd have to disagree with Jack. Until then I'll just disagree with you. verbiage, I think yes, bit fields are described fully in the standard, I guess whoever wrote "not really a solid part" really should have written "this is a section where almost every other word is 'implementation defined'"
The "no easy seamless portability" issues comes to a large extent from the 'implementation defined' sections of the standard. That C would have been miserable to process on some processors had these thing not been 'implementation defined' is another story.
I, for one, "have a lot of fun" processing some data which is a bunch of structures written by a processor where the byte order is "the other way around".
Well, like I just said, writing them to files is exactly what C structs are not for. Don't blame programmer's silly decisions on their tools.
Hans-Bernhard, I did not have control over this, it was so, long before I joined the company. Anyhow, without going into non-disclosure requirements, I think it is the most effective form for transferring this which hold about 75 groups of totally varying information.
Anyhow, if you have a better idea for how to transfer in one transmission about 75 groups of totally varying types of information I would love to hear it since gen 4 of this is about to be defined.
Experienced developers packs/unpacks all data themselves when sending the data on communication links or keeping non-volatile data.
This isn't a limitation of bit fields. But it is always a stupid idea to transmit raw memory structures or to to permanently store raw memory structures.
It doesn't matter if we talk about bit fields or if we talk about unions or even just an array of integers. The data should have a known format. Either pre-defined or containing flags that tells the load code which byte order to expect.
Transmitted or stored data should be described by a 100% complete document and the load/save code should make sure that the document and the reality matches.
By taking care of these issues, I don't have to worry about the next compiler changing the algorithm for packing structures or allocating bit fields from high or low bit. And if I did store the data in an internal flash sector of my ARM, I can modify the code a bit and instead write the same data to a SD memory and move that SD memory to a PC and correctly read the data. Or I can add XMODEM and transmit the saved data to a different unit using whatever processor and it will be able to process the XMODEM data and use the same code to restore the original information.
You seem to be saying that my statement:
"I care about efficiency <snip>"
Contricts my other statement:
"Wrapping code in preprocessor directives doesn't make it portable - in fact, it makes it clear that it is non-portable"
You are very confused.
translated "if cost is an issue, do not involve the person hiding behind "Jack Sprat", he cares more about his fanciful ideas"
Sensible design isn't a fanciful idea.
Oh, have you decided yet whether my assertion that you haven't read the 'C' standard remains baseless?
I'd be unlikely to have designed my way into a situation where a bit operation rather than a byte operation would make the difference between project success and project failure.
so would I. Confound it, can you not understand what an example is, www.merriam-webster.com/.../example see 3)
Gosh, I had 5 definitions to choose from! Ok, but you think number 3 might suit your purpose:
"one (as an item or incident) that is representative of all of a group or type"
Here we go:
I'd be unlikely to have designed my way into a situation where anything of the group or type represented by a bit operation rather than a byte operation would make the difference between project success and project failure.
"Wrapping code in preprocessor directives doesn't make it portable - in fact, it makes it clear that it is non-portable" if you do not "Wrap code in preprocessor directives" it can never be portable by the "sardine standard" and efficient. e.g. if you do not have a preprocessor directive for using 'bit' when running on a '51 your code is not efficient. Did that bend it in neon so you can see it? One one hand you claim the efficiency is not important, on the other you calim that the "sardine standard code" is not inefficient
You are very confused. here you go again making statements about me that you have no background for making.
I care about efficiency where efficiency is the most important factor. With sensible design, however, it rarely is. so, "sensible design" makes effciency irrelevant. I have always thought that "sensible design" was efficient desitgn.
Sensible design isn't a fanciful idea. by most peoples definition no, by yours yes
OH BOY, after posting that 'bit' is but an example, you write: I'd be unlikely to have designed my way into a situation where anything of the group or type represented by a bit operation rather than a byte operation would make the difference between project success and project failure. I stated (clearly to all but you) that using 'bit' was an example of where adapting code to a particular processor/compiler would affect efficiency. I am not going to waste my time on listing other examples if you do not know what they (or, at least, most of them) are, you will be lost anyhow. Then on the other hand since you state that efficiency is unimportant what would you care. I am sure the processor makers love you for buying a more expensive (faster, bigger) derivative than anyone else would need, just to make the code fit the "sardine standard"
PS do you do CAN
I stated (clearly to all but you) that using 'bit' was an example of where adapting code to a particular processor/compiler would affect efficiency.
An example, according to your favoured definition, is representative of a group or type. You are now arguing that what you presented as an example is not representative of what you meant. This makes no sense.
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