Fish 'n' More 2/fishmore-publicdomainlibraryvol.ii1991xetec.iso/fish/languages/northc_384/questions

Text File | 1990-10-23 | 10KB | 222 lines

(c) 1990 Steve Hawtin.

  Over the last few months, since NorthC was first released, quite a few
people have written to me to ask about NorthC, usually they also add some
supplementary questions, I thought it would be worth putting down the answer
to some of these queries so that you have to think of more interesting ones.


1. What books on 'C' should I buy?

  Since 'C' is the current "fashionable language" there are a vast number
of books on 'C' around, mostly written by the people who were writing
books on Artificial Intelligence a couple of years ago and know just as
much about 'C'.  If you want to buy a book on 'C' here are some that I can
recommend.

  "The C programming language" by Kernigan & Ritchie.

  If you want to learn 'C' this is the best book, it may be hard going at
first but unlike many "easy" books you will still be using after a year of
'C' programming.  This is the book that professional 'C' programmers use
as a reference.  You will find a copy almost everywhere 'C' is used
seriously, normally dog-eared and grey from overuse.  There are two
editions of this book, the original edition and the ANSI edition, you
should not worry about which on you get, although the ANSI one is more up
to date most 'C' compilers will be closer to the old edition for some time
to come.

  "C traps and pitfalls" by Koenig

  For the experienced 'C' programmer this book is a must, it points out
many of those nice little quirks that trap everybody from time to time.
This book collects together a vast body of 'C' experience, once you know
the difference between a union and a structure this book will tell you all
the things you didn't realise you didn't know.

  "Standard C" by Plauger & Brodie

  The best book I have seen on the ANSI standard, this book is a reference
guide rather than a "how to" book.

  "Amiga ROM Kernel:Libraries & Devices" by CATS
  "Amiga ROM Kernel:Includes & Autodocs" by CATS

  These two books are the complete guides for the Amiga specific bits,
most of the examples are in 'C', but you will have to get hold of the
include files.  The first book introduces AmigaDOS and gives examples of
how to do things with the machine, the second is the ultimate reference
book for Amiga specific programming.  If you are buying these make sure
you get the right version for your version of workbench, currently the
ones in the blue covers for Workbench 1.3.


2. Is NorthC ANSI compatible?

  The answer to this question is no, although I have tried to use ANSI
functions where I can there are still many areas where the compiler falls
short of the standard.  The "Bugs.doc" file outlines the areas that do not
conform.

  The ANSI standard clearly states that compiler writers are not allowed
to claim ANSI conformance unless they implement everything in the
standard, however this has not stopped certain companies claiming to have
ANSI 'C' compilers when they do not support multibyte characters and
locales.  As yet I have not managed to find a true ANSI 'C' compiler.


3. Is NorthC shareware or public domain?

  The answer to this question is no, NorthC is neither public domain or
shareware.  Shareware programs are programs that are distributed by the
public, but if you use them, or want an up to date copy, you must send
some money to the authors.  Public domain programs are programs that you
can do anything with, they belong to the public.

  Most of NorthC is copyright to the original authors, myself, Charlie
Gibbs, the Software Distillary and so on, however the copyright holder has
allowed other people, this means you, to copy their programs and data
provided you stick to certain rules.  These rules normally just say that
you are not allowed to use the stuff for commercial gain, see the
individual files on the disk to find out the full set of restrictions for
each program.

  If you feel that I deserve some money for the hard work that I have put
into this disk send £15 or $25 to your national spastics charity, they
need it more than I do.  If you feel that some of the other people that
contributed deserve some recognition please send them any money direct.


4. Why isn't the NorthC disk bootable?

  Well the reason for this is that I could not create a bootable disk
without including some programs by Commodore.  It is easy to create a
bootable NorthC floppy, just copy your workbench floppy, delete all the
bits you don't need, the ".icon" files, all the fonts except topaz, the
commands you don't want.  Then move "NorthC", "A68K", "Blink", and "make"
to the Utilities directory, move the contents of the "include" directory
on to the disk, create a directory called "clibs" and move "crt0.o" and
"libc.a" into it, and add the lines

    assign clibs: :clibs
    setenv INCLUDE df0:include
    newshell "newcon:0/10/640/246/NorthC 1.2 Shell"

into "s:startup-sequence" to replace the "loadwb" line.  On NTSC systems
the newcon command should of course read

    newshell "newcon:0/10/640/190/NorthC 1.2 Shell"

  If you have problems fitting all this on a single floppy I have been
told that "Power Packer" by Nico Francois is a useful tool for squeezing
more programs on a disk, it is distributed by Fred Fish, ask your local PD
supplier for the disk.

  Once you have created a bootable floppy in this way you are not allowed
to give copies away, that would break some of the rules for copying the
programs.


5. Where do I get the AmigaDOS include files?

  You will notice that the NorthC 1.2 disk does not contain the AmigaDOS
include files, I asked Commodore if I could put them on the disk but they
refused.  To get them you can either type them in from "Includes &
Autodocs" or you can write to Commodore and ask to become a "registered
developer", this will cost about £20 in the UK, presumably a similar
amount elsewhere.  Commodore will send you the include files and various
other useful bits and pieces.  I have been told that it is well worth
doing.  See the "README" file on the NorthC disk for more details.


6. Why do you give away your software?

  This is one of the most difficult questions I am asked, here is a
selection of answers

  0. Because its needed.
  1. Because its there.
  2. Because I cannot sell it.
  3. For the money.
  4. Because I think more Amiga users should have access to 'C'.
  5. Because software should be free.
  6. To encourage users to purchase Lattice C.
  7. As an Erisian it is my duty to spread knowledge.
  8. For the fame.
  9. Just because...

  Some of these answers are true, some are false and some are meaningless,
you will have to sort them out yourself.


7.  How did you port NorthC

  Before I answer this question I should point out that I have written
programming languages before, in the last ten years I have written a
"Forth" interpreter, a "Scheme" interpreter and compiler, and been
professionally involved in "Common Lisp" interpreters and compilers.  So
the idea of porting a 'C' compiler was not as horrendous as it should have
been.

  When I bought my Amiga in December 1989 I assumed that I would be able
to get hold of a complete 'C' system in the public domain, in fact what I
found was

  1) Sozobon C, on FISH 171, an "almost ported" 'C' compiler.
  2) SmallC, on FISH 141, a working but very limited 'C' compiler.
  3) A68K, on FISH 186, a working assembler.
  4) Blink, on FISH 40, a working linker.
  5) SmallLib, on FISH 92, a small library for assembler programmers.

one problem with Sozobon was that the output was not compatible with any
of the Amiga public domain assemblers.  So my first step was to create a
program "convert" that read a ".s" file produced by Sozobon and converted
it into a ".asm" file that A68K could deal with.  I wrote the first
version in SmallC, this finally convinced me that SmallC was not the
language for me.  I now could compile 'C' programs in three steps,

  1) hcc test.c
  2) convert test.s test.asm
  3) a68k test.asm

using this I created some 'C' library functions, and used these to create
a new version of "convert".  I then ran the Sozobon compiler through this
three stage compilation process, the resulting program summoned the guru
of course.  After two months of continual work modifying the Sozobon
source I managed to get the compiler sort of working.  Once I had a
version of the compiler that could compile itself I changed the output
routines to make the "convert" program unnecessary.

  As soon as the system was stable I released it, I thought that it was
worth sending out a version that was incomplete so that people could start
to play with 'C'.  I called this first release NorthC 1.0 because the
original source has been so heavily hacked the program was sure to contain
many new and exciting bugs, this was distributed by Fred Fish on FISH
340.  After two more months I had a version I felt happy with, I released
this at the start of May as NorthC 1.1.  Having spent almost every evening
for more than four months working on NorthC I decided to give it a rest.

  As a passing thought if I had just bought a copy of Lattice when I
started I would have saved myself a large amount of time and money.
However I would not know as much about 'C' as I now do.


8.  Are you trying to replace Lattice?

  In a sense the answer to this question is yes, when I first started
working on NorthC I could have got an illicit copy of Lattice and used
that to develop my 'C' programs, however I felt that it would be better to
have a legitimate 'C' compiler.  So I hope that NorthC and the other
public domain 'C' compilers will replace all the illegal copies of Lattice
that are floating about.

  Of course the Lattice compiler is a professional piece of software, the
documentation is better, and in hard copy, I would assume the code produced
is quicker and more compact, and the software support on Lattice is better.
If the size and speed of the final program matters enough to spend the
money then you should go out and buy a professional compiler.  Until that
time comes you can carry on using NorthC, any code you write should work in
any half descent 'C' compiler.