On 2001.08.12 15:02 David O'Brien wrote:
> On Sat, Aug 11, 2001 at 12:18:57PM -0700, John Merryweather Cooper wrote:
> >
> > Since when does any self-respecting compiler dictate object format?
> It's
> > brain-damage for a compiler to screw with the object format--so much
> for
>
> If you have ever programmed in Ada, you would understand. Since I assume
> you have not due to your comment, you should learn something more about
> languages and implementation than just "C" -- it makes one very myopic.
>
I have programmed alot in Ada--and I understand about meta-deta and it's
uses. But that's not what I took the original claim to be--I took it to be
advocacy for private object formats for every compiler. Clearly I stepped
on a "troll-mine" . . .
> Also, to put the in formation in the object format does not require
> changing it. Do you think all debugging metadata is standardized? One
> can put optional data in object files.
>
No, I'm well aware that meta-data is not standardized by any means.
Obviously, the original comment that started this whole discussion was a
little vague, and I got trapped.
>
> > Prototypes are an overwhelmingly "Good Thing(tm)"
> > as behind-your-back implicit parameter conversion is death to serious
> > numerical work. At least now, some control can be exercised over
> parameter
> > conversions . . .
>
> Who ever said anything about not being able to do that in Terry's view?
> You are taking one statement and running wildly with it.
>
In my view, he was advocating chucking ANSI-89 and returning to the wild
days of K&R. I think that would be very bad. Clearly, you disagree with
my understanding.
>
> > Two-pass lexing is also brain-damage. How to easily double compile
> time is
> > a single step. If applied to C++, we'd wait night and day for the
> compile
> > of just one port.
>
> *sigh* Do you really, really think most of the time you spend in
> compiling a C++ file is in the lexing step??
>
In benchmarking IBM's VisualAge C++ (Version 4.0), this seems to be the
case, at least for me. I chose this compiler because it is easy, with the
tools available for me to monitor the stages of compilation since each
stage has a separate DLL. Using SciTech's MGL 5.0 Beta 2 Library, it is
clear that Lexing/pre-processing take up the lion's share of the time.
Obviously, your mileage differs. I would like to have your understanding
of what's happening--and not this "troll-mine."
> BTW, what do you think happens in C with the preprocessor? You are
> lexing things twice -- once by the preprocessor and once by the compiler
> proper. Quite often they share common lexer code.
>
Not always. Provided you out-law macros with side-effects, it is perfectly
possible to preprocess and lex simultaneously.
>
> > Also, languages that are deliberately ambiguous are
> > maintenance nightmeres--maintenance perfers a language that is 100%
> > deterministic.
>
> You think C++ isn't ambiguous, and that new features haven't been added
> to it knowing that it blows ambiguity out of the water?
>
I know it's ambiguous. In fact, I think it's the most poorly
standardized/described language to date. However, since C++ is quite
popular, apparently my opinion doesn't carry much weight. :)
>
> > Seriously, my
> > understanding from K & R is that the C designers just thought it would
> be a
> > "nice feature" to allow both versions of the operators. "Nice feature"
> is
> > usually a synonymn for brain-damage in a compiler. :)
>
> *sigh*... little knowledge, great stretching leaps...
>
>From the reading I've done, I believe this conclusion is justified.
Doubtless there are other opinions though . . .
>
> > And that is as it should be . . . Lexing to be fast needs to be
> > single-pass. The same could be said for parsing. The agony over
> designing
> > a truly "standard" C++ compiler (not a single example of which exists)
> > should lay this out clearly . . .
>
> WTF are you talking about? I don't see the required connection between
> the two. Please tell me the compilers have detailed knowledge of their
> innerworkings.
Now you swear at me. Hardly constructive. Like I said, a "troll-mine."
I'll step more carefully in the future. I'm nothing compared to you, but
your resort to ad hom's instead of illumination indicates that further
discussion would be irritating and pointless.
jmc
>
> --
> -- David ([EMAIL PROTECTED])
>
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