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Groups > comp.os.msdos.programmer > #1105

Re: Smaller C compiler

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On Wed, 04 Dec 2013 01:22:21 -0500, Alexei A. Frounze  
<alexfrunews@gmail.com> wrote:
> On Tuesday, December 3, 2013 9:23:45 AM UTC-8, Rod Pemberton wrote:

> At the moment I'm the least concerned about complete implementations of  
> formatted I/O functions and about the speed of operation. There are some  
> more pressing areas (cleaning up error checks/messages, implementing  
> struct and casts).

Are you interested in making the program's code ANSI C?

> What I'm more concerned about in terms of the standard library is the  
> common functions operating with long ints, like ftell() and fseek().  
> There's no support for 32-bit integers in 16-bit code and yet long ints  
> can't be shorter than 32 bits and DOS file sizes are 32-bit.

I would think TCC and Borland C would be 16-bit too.

Except for a few pointer construction macro's and calls to DOS functions,
I don't recall much difference between programs compiled by OW as both
16-bit and 32-bit.  But, I haven't done much in-depth with OW in a few
years.

> Looks like as a workaround I'll need to implement _ftell() and _fseek()
> taking and returning 32-bit values as pairs of 16-bit ones.

:-)

There is a reason DJGPP doesn't support 16-bit.
There are reasons LCC stopped supporting 16-bit.

> Support for longs isn't coming soon.

Isn't that the same issue as above?

> It'll require reworking of code in a fair number of places (and the most  
> problematic of them is the code generator) and the code and data size of  
> the compiler will significantly grow as a result of supporting longs,  
> likely making it no longer self-compilable in 16-bit.

Don't they use different integer sizes in C for different modes on x86?

> I might need to start using far pointers to address more than 64K of the  
> code and then I'd use far pointers for data as well and to support far  
> pointers, I'll have to support far pointers, meaning even bigger and  
> complex code generator! :) OK, this isn't the only possible option, but  
> the long problem needs some research.
>

IIRC, far and near pointers and some other incompatibilities with the
C specifications was why LCC stopped supporting 16-bit.  v3.5 and v3.6
supported DOS.  v4.1 and v4.2 stopped.  I never got around to it, but
it looked like the changes were very minor, i.e., like maybe v4.1 or
v4.2 had a good chance of being made to support 16-bits.

>> However, with some work, you can usually eliminate all
>> internal code that uses memory by preferencing file
>> I/O functions.  So, you can eliminate sprintf(), sscanf(),
>> in favor of fprintf(), fscanf(), etc.
>
> Internally, my *printf()'s share most of the same code.

I was looking at your externally declared functions.
I thought you were using an available external library
for them.

>> vsprintf()
>> vprintf()
>> vfprintf()
>>
>> I've not use v*printf() functions much.  So, it should be
>> possible to eliminate these by using other printf functions,
>> depending on what you're using them for.  If you're using
>> them to handle variadic argument lists, then you could use
>> a stack.
>
> Well, the thing is... Take a look at the following declaration
> in the compiler:
>
> void error(char* format, ...);
>
> How do you think error("Something horrible happened at %d!\n", 404);  
> gets its arguments out? It uses va_list and vprintf().

Well, you don't have to do it that way.  You could use printf()
directly.  You could use fprintf() directly.  You could use
sprintf() to a buffer and then a puts().  You could use one printf()
for the string and another for the integer, e.g., string looked up
in table.  You could pass only one string to a custom error
function after formatting.

> And vprintf() is underneath printf() anyway.

In yours? OpenWatcom? DJGPP? ... DJGPP uses a central print routine
which is mostly printf().  I'm not sure about OpenWatcom.

> I do not feel like disfavoring anything from the used subset
> of the standard library functions.

It was just suggestions in case you wanted to reduce the quantity
to make bootstrapping easier.  But, you're bootingstrapping with
modern C compilers with complete C libraries, so none of that is
probably even needed.


Rod Pemberton

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Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-01 08:15 -0800
  Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-01 18:42 +0000
    Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-01 19:14 -0800
      Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-02 11:13 +0000
        Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-02 03:21 -0800
          Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-03 06:21 +0000
            Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-02 23:17 -0800
              Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-03 13:31 +0000
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 06:05 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-03 10:47 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 21:18 -0800
  Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-03 12:23 -0500
    Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-03 16:26 -0500
      Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 23:58 -0800
        Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-04 04:31 -0500
          Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-04 05:01 -0500
            Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-04 02:20 -0800
              Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-05 06:33 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-05 21:37 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-06 12:19 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-06 22:23 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-07 13:48 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-07 16:34 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-08 02:12 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-13 03:32 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-15 04:47 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-15 02:14 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-15 13:21 -0500
          Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-04 23:39 -0800
            Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-05 06:38 -0500
              Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-05 21:40 -0800
              Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-06 04:19 -0800
                Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-06 13:40 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-14 21:07 -0800
    Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 22:22 -0800
      Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-04 04:30 -0500
        Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-04 23:21 -0800
          Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-05 04:23 -0500
            Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-05 21:31 -0800
  Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-10 04:59 +0000
    Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-10 06:17 +0000
      Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-11 02:36 -0800
        Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-11 13:44 +0000
  Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2013-12-10 10:41 -0800
    Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-11 03:06 -0800
      Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-11 10:47 -0500
        Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2013-12-11 08:01 -0800
          Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-11 13:40 -0500
        Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-11 22:07 -0800
        Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-25 02:33 -0800
          Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 03:24 -0800
  Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-21 15:55 -0800
  Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-29 17:16 +0000
    Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-29 21:54 -0500
      Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 19:38 -0800
    Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 19:36 -0800
      Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-30 05:07 +0000
        Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 21:58 -0800
        Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-01-05 19:43 -0800
          Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2014-01-06 15:27 +0000
            Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2014-01-06 19:51 -0500
              Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2014-01-07 04:27 +0000
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-01-06 21:52 -0800
          Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-02-16 22:57 -0800
            Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-02-25 00:17 -0800
              Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-03-01 21:31 -0800
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-03-10 01:46 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-04-20 20:19 -0700
                Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2014-04-23 11:20 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-04-23 11:41 -0700
                Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2014-04-25 06:08 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-09-14 03:06 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-11-09 03:26 -0800
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-11-28 04:06 -0800
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-12-21 01:56 -0800
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-01-10 10:37 -0800
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-04-19 23:55 -0700
                Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2015-04-22 06:13 +0000
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-04-22 00:12 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-04-25 21:11 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-05-16 17:49 -0700
                Re: Smaller C compiler "Bill Buckels" <bbuckels@mts.net> - 2015-05-19 20:01 -0500
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-05-19 18:18 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-08-15 02:13 -0700
                Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-06 15:55 -0700

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