Making Fatal Hidden Assumptions

... snip ...

Even lower than you think, especially when the programmer has taken advantage of sub-ranges and typed everything as tightly as possible. In this case a good Pascal compiler can compute the possible range of expressions, and avoid most runtime checks. This has the minor disadvantage of not checking for hardware errors.

Apparently I have failed utterly to make myself clear. I'll try one last time.

You claim that C is, in some sense, an assembly language (specifically, a "portable assembly language"). I'm assuming here that any "portable assembly language" is an "assembly language".

I claim that C is not an "assembly language", though it may bear some resemblance to one.

I am not offended by the claim, I simply disagree with it. My disagreement is based on my knowledge of the C programming language and my understanding of what is meant by the term "assembly language". (I haven't tried to provide a definition of the term myself; I might or might not make the attempt later.)

I used the word "us" simply because we are having this discussion in a public forum. Anything you post here will be read by multiple people, including me -- thus "us". Nothing more.

There should be some definition of the phrase "assembly language". If C is an assembly language, then C should meet the requirements of that definition. This line of reasoning seems obvious and unremarkable to me; do you disagree?

I agree. It does not follow from this, though, that the term "portable assembly language" is necessarily meaningful, or that it applies to C even if it is meaningful.

If someone cries "portable assembly", I can either figure out what they mean, or I can decide they're crying nonsense. I'm content to do either or both.

So, finally, what do you mean by "assembly language"?

Here's what you wrote upthread:

] C was designed as a portable assembly language, the most successful so ] far, so if the term has any practical meaning, then C is that meaning. ] ] C was designed as a portable assembly language for the purpose of ] porting Unix (which then had some seven or ten installations, I ] forget, but one rumor has it there was only one, namely the PDP-7) ] more easily. That didn't fully remove the need for using actual ] assembly. But only some small parts still needed to be ] machine-specific assembly.

So you're using the term "portable assembly language" while insisting, in contradiction to ordinary English grammar, that a "portable assembly language" is not necessarily an "assembly language". ("Portable" is an adjective; "assembly language" is a noun phrase.) And yet you seem surprised that I'm having trouble figuring out what you're talking about.

I'm done here.

• Keith Thompson:

If it were as want it to be, then "portable assembly" would be a contradiction in terms... :-o

You cannot extract meaning or conclude from a self-contradiction.

By the rules of logic, that is.

Yes, you have managed to suprise me continuously. Nobody can be that stubborn, I think. And yet you come through; ignoring logic, ignoring examples, ignoring established usage, insisting that your own extremely little irrelevant subset of language rules is what "should" apply.

Well done, I might add. If not to say roasted.

Complete nonsense. Read what dmr himself writes about this: .

C was designed as a systems programming language for (then) a single, new OS, _not_ a portable assembler. In fact, that article explicitly states that a. one of the reasons that drove the evolution of C's ancestors, and later C itself, was _not_ to have to use assembler and b. portability was not yet a concern in the first days.

Ah, well, yes, if you get your information from Wikipedia, where any little fool with a complete misunderstanding of his subject can, and last time I looked at that page in fact _had_, turned an article into a mix of some seeds of fact, some serious misconceptions, and quite a bit of complete bollocks, then I'm afraid I cannot take your opinion on any subject seriously, certainly not on C.

Richard

This is a fallacy known as "Appeal to Ridicule". To quote one source:

This sort of "reasoning" is fallacious because mocking a claim does not show that it is false. This is especially clear in the following example: "1+1=2! That's the most ridiculous thing I have ever heard!"

Why should I read that yet again? Quote what you think is relevant.

All that is correct and irrelevant. Why do or did you think it should or would be relevant? Perhaps you're just objecting as best you can to terminology that seems frightening to you, and even appears new to you; perhaps can help?

The above is several fallacies lumped into one spaghetti fallacy. But the main top-level fallacy is known as "Poisoning the Well". Don't you think you should perhaps restrict your usage of fallacious reasoning?

If you can't define what a term means, then it is meaningless and so it is pointless to use that term with reference to anything.

Well, you don't need to be told what you mean (I assume) so it is everyone else that needs to know in order to understand what you are trying to say.

No one has expressed any offence at the term that I've seen, they have just disagreed.

Suggesting that the people who disagree with you have an inferiority complex, on the other hand, is insulting.

All completely irrelevant to the discussion at hand.

I'll give some attributes that I consider essential to an assembler, and whether or not C has them:

- The ability to write Interrupt Service Routines - Not possible in C since there is no mechanism to specify that a routine is an ISR and some processors use different calling conventions for IRSs.

- The ability to access the status flags of the processor, including such flags as overflow flags - Not possible in C, if a calculation overflows you invoke undefined behaviour

- The ability to access IO ports on the processor - Not possible in C. You can access memory mapped devices, but not IO mapped devices.

I could go on.

Indeed, since C does not come close to any definition I would use. Also, what do you mean by "portable assembler".

BTW, I've done embedded programming, including writing interrupt service routines, accessing IO ports (as opposed to memory mapped devices), accessing memory mapped devices etc all in a few different extended versions of Pascal. So from my perspective Pascal is about as close to assembler as C is.

Every C compiler I've used for the last 2exp(N) years (apart from perhaps the ones for specific OSs like Windows, where I've simply not looked) has had this facility. It's not C- it's an extension, and it's very annoying that they are all different- but it's there.

Same as above.

Plus necessary constructs to direct unchanging objects to ROM, again all compilers different.

But you're right (whoever said it), it's nowt like an assembler. It's just a quick and dirty middle- level language, and to use it you really need to know the hardware yoiu're operating on in many cases.

It seems that the little embedded stuff is considered simply below the radar for the standards committees. Perhaps that's a good thing.

Paul Burke

• Flash Gordon: > [snipped anonymous babble]

What is the question?

-- A: Because it messes up the order in which people normally read text. Q: Why is it such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail?

I don't think that's true, if only because you have to start with /some/ terms that don't have definitions.

Meaning is prior to definition.

Clarity and/in communication, that's the ticket.

You snipped the part where I pointed out that you can do all this in the various forms of extended Pascal I've used, so if you allow extensions Pascal is just as low a level language as C ;-)

Agreed. Despite my comment above, I would say that Pascal was a higher level language than C.

Well, those odd little corners in my experience are only a small fraction of the code, so I don't see it as a big issue.

I don't know why you call it anonymous, since I am not posting anonymously. Or if I am, it is about the worst attempt ever at being anonymous.

I wasn't asking a question, I was refuting points you raised and pointing out why C is not any form of assembler, including a portable assembler. It's not my fault if you don't understand a lot of the things I spent many years using assembler for, or the various things you cannot do in C that you can easily do in assembler.

Just about any language than isn't pure OO (I'm not 100% sure on that point, I just can't imaging pure Java in this role) can be extended to do this. DEC even sold an operating system written in BASIC.

So what is the point of this discussion? No language can replace assembler without extensions, any attempt to standardise a hardware layer would be doomed.

If C was intended as an assembler, the original PHP UNIX would have been pure C, which it wasn't.

...

i don't know what "portable assembly language" is (because for an assembly there is a cpu and "

Nonsense. C is not and cannot be an assembly language, portable or otherwise. Now *your* implementation of C might provide extensions, or you might create them yourself to access specific features of the target processor, but that is beside the point.

Standard C is not an assembly language, portable or otherwise. Anyone who thinks so has a dilute conception of assembly language.

but this seems to compile and to run here (Borland C compiler)

#include #include #include

int main(int argc, char** argv) { asm{push ebx;} /* printf("arg0=%s\n", argv[0]); */ _EBX=argv; if(!(_EBX==0)) goto c1; c0: {asm{pop ebx;} _EAX^=_EAX; return;} c1: _EBX = *(int*)_EBX; /* ebx= argv[0]*/ if(_EBX==0) goto c0; strstr((char*)_EBX, "prog.exe"); if(_EAX==0) goto c0; _EBX=_EAX; _EBX+=strlen("prog.exe"); _BL = *(char*)_EBX; if(!(_BL==0)) goto c2; {printf("i nomi sono uguali\n"); goto c3;} c2: {printf("il nome e' piu' lungo \n");} c3: goto c0; }

PLONK

Please stop posting this non-portable non-standard crud in comp.lang.c.

Pompous insults are Alf's usual recourse when he's confronted with someone willing to point out that his arguments are vacuous.

I haven't killfiled him because he occasionally has something worthwhile to say in technical discussions, but in an argument of this sort it's best just to ignore him. If past behavior is any indication, he'll just try to shout everyone else down until we all get tired of him and give up.