Gpc August 1997

gpc@gnu.de

23 participants
88 discussions

Re: Pointer & GPC question...
by Frank Heckenbach 20 Aug '97

20 Aug '97

Orlando Llanes wrote: > > (*$ifdef __MSDOS__ *) (* The definitions are case-sensitive *) > > ... > > (*$endif *) (*$endif *) (*$endif *) > Thanks :) Use them with care! This way, you can only support some limited set of known platforms, but the GNU compiler is ported to more and more platforms... Whenever you can, you might want to use portable way of doing things. E.g. to distinguish whether a pointer has 32 or 64 bits (or more), you can use "sizeof(pointer)"... > > For an example what I mean, look at Sven's excellent `BGI2GRX' Unit, > > also known as GPC's `Graph' Unit. > I saw it, but nothing about memory access, besides, I don't see why > Borland's BGI should live on. (* BTW: BGI2GRX doesn't use Borland's inefficient BGI drivers and such, it just provides the same (nearly) interface as Borland's Graph unit. *) -- Frank Heckenbach, Erlangen, Germany heckenb(a)mi.uni-erlangen.de http://home.pages.de/~fjf/links.htm

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Correction...
by Orlando Llanes 19 Aug '97

19 Aug '97

Errr... I DO want to retain the Copyright. -- See ya! Orlando Llanes

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Re: Pointer & GPC question...
by Orlando Llanes 19 Aug '97

19 Aug '97

Thanks :) > (*$ifdef __MSDOS__ *) (* The definitions are case-sensitive *) > ... > (*$endif *) (*$endif *) (*$endif *) Bummer :( > No way. Will do. > For DJGPP, see the GPC FAQ and the DJGPP FAQ. The "best" way for direct It is, but for starters I want to do it high level, I don't know much about PMode yet. In fact, I may not even have to code in low level ASM, reason I say this is because I saw a Mode-X lib (XLib for GCC I think), and upon examining the source, I didn't see a single ASM statement in it. > memory access IMHO is to use assembler. You can use the following function > to convert a segment address to a selector: Noted :) > Function SegToSel ( Seg: ShortWord ) Sel: Word; > ... > end (* SegToSel *); That's the problem, I heard SVGALib is a bit slow. Besides, I don't plan on going Linux just yet, once I have a strong base in PMode/DOS I'll work on the Linux port. I may use SVGALib for short term tho. > For Linux, better don't access memory directly. Instead, use (S)VGALIB or > some other well-documented interface to graphics mode. I plan to put it in the license where it's Copyrighted Freeware :) Hopefully it's what the LGPL stands for. I will release the source code, but I don't want to retain the copyright, I won't charge for it's use tho. > Sounds good. Do you consider to put it under the GNU Library General > Public License? Heard of it, saw the demo Caveman, and didn't like it much. The sound lib won't run under '95, I don't know exactly where the problem is, but I want the lib to run efficiently under a Full Screen Windows '95 DOS Box without being prompted to run in MS-DOS mode. I'll take a look at it tho, maybe it can tip me off on how to set the address of a pointer :) My ultimate goal is to provide an API so that it truly is recompile source on each platform and compiler rather than re-edit to recompile. > For DJGPP, there is a game library called `Allegro' for GNU C. > ... > good starting point for you to write such a Unit to use `Allegro' I saw it, but nothing about memory access, besides, I don't see why Borland's BGI should live on. I plan to make my libs work in VGA, VESA, VBE2, and certain Mode-X configurations. > For an example what I mean, look at Sven's excellent `BGI2GRX' Unit, > also known as GPC's `Graph' Unit. See ya! Orlando Llanes

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Re: Pointer & GPC question...
by Peter Gerwinski 18 Aug '97

18 Aug '97

According to Orlando Llanes: > > Do you have access to these machines for beta-testing? Yup. > That reminds me, are > there definitions for the environment GPC is compiling for? For example: > [...] Yes: (*$ifdef __MSDOS__ *) (* The definitions are case-sensitive *) ... (*$else *) (*$ifdef __osf__ *) (* One operating system for the Alpha *) ... (*$else *) (*$ifdef __linux__ *) (* Another operating system for *) (*$ifdef __i386__ *) (* the Alpha - or for the i386+ *) ... (*$else *) (*$ifdef __alpha__ *) ... (*$endif *) (*$endif *) (*$endif *) (*$endif *) > How do I set a pointer to point to the VGA (for example) in a way that can > be ported to at least Linux? No way. For DJGPP, see the GPC FAQ and the DJGPP FAQ. The "best" way for direct memory access IMHO is to use assembler. You can use the following function to convert a segment address to a selector: Function SegToSel ( Seg: ShortWord ) Sel: Word; begin (* SegToSel *) asm ( 'int $0x31' : '=a' ( Sel ) : 'a' ( 2 ), 'b' ( Seg ) : '%eax', '%ebx', '%ecx', '%edx', '%esi', '%edi', '%ebp' ); end (* SegToSel *); For Linux, better don't access memory directly. Instead, use (S)VGALIB or some other well-documented interface to graphics mode. > I'm going to start work again on my game lib > (graphics part), and M13h would be a start :) Another thing is how do I > modify the contents referenced by the pointer? Writing a byte so it's > portable, writing a word so it's portable, etc. My ultimate goal is to port > this lib to PMode DOS, Mac, '95, Linux, X, and whatever other platform I > can get my grubby hands on, but I'll settle for PMode DOS for now :) Sounds good. Do you consider to put it under the GNU Library General Public License? For DJGPP, there is a game library called `Allegro' for GNU C. To use it with GNU Pascal, you only need to translate the C header files to a Unit with empty implementation part. I think, `Allegro' is under the GNU LGPL, so it is available in source code. Maybe it's a good starting point for you to write such a Unit to use `Allegro' with GPC? For an example what I mean, look at Sven's excellent `BGI2GRX' Unit, also known as GPC's `Graph' Unit. Greetings, Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [970201] maintainer GNU Pascal [970714] - http://home.pages.de/~gnu-pascal/ [970125]

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Testing...
by Orlando Llanes 18 Aug '97

18 Aug '97

Please don't flame me for this, I wrote to this mailing list, and it somehow ended up in the wrong e-mail address. See ya! Orlando Llanes

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Pointer & GPC question...
by Peter Gerwinski 18 Aug '97

18 Aug '97

According to Orlando Llanes: > > Ok, I know you guys are gonna shoot me for this, but here goes anyway... No. To become shot by myself, you must do more than this. ;-) > My question is about Pointers, what I want to know are 3 things.. > 1) What is the format of a pointer? Is it 3 bytes (selector--1 byte, > base address--2 bytes)? Or is it 4 bytes? On iX86-based machines, pointers have four bytes; all of them "offset" (that's what you probably mean with "base address"). GPC works in just one memory segment with a maximum length of 4GB, while 16-bit compilers usually work in many memory segments of 64kB each. On other machines, pointers are different; e.g. on the DEC Alpha, a pointer has eight bytes. > 2) If I performed pointer arithmetic that works under MS-DOS, will it > also work under Linux without modification? Yes. Provided you use GPC's pointer arithmetic as implemented in gpc-somewhere-in-may-or-so. Casts to `Word' and such are *not* portable. > 3) How do I create a generic pointer? Can I just use "Pointer"? reason > I ask is because I tried plain Pointer once, and it didn't work. It works now. :-) > Another question I have now while we're at it, is the latest version of GPC > posted on the FTP site? Or is it still in patched versions? I want to > upgrade, but I don't want to mess with patches unless I could upgrade from > 2.01 Where can I find the upgrade? >From 2.01? What's that? While the official version of GPC is still 2.0, the latest beta version that is available in binary form is gpc-970714, available via ftp at ftp://agnes.dida.physik.uni-essen.de/gnu-pascal/beta/binary/. Some patches to gpc-970714 already exist on Agnes, too, but they are no official new beta yet. Due to administrative problems :-(some paper war must be resolved first - sigh)-: I am retaining more recent sources, but some bug fixes have been posted to this list now and then ... Hope this helps, Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [970201] maintainer GNU Pascal [970714] - http://home.pages.de/~gnu-pascal/ [970125]

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Re: Pointer & GPC question...
by Orlando Llanes 18 Aug '97

18 Aug '97

<grin> > No. To become shot by myself, you must do more than this. ;-) Do you have access to these machines for beta-testing? That reminds me, are there definitions for the environment GPC is compiling for? For example: {$ifdef DOS} DOS specific stuff {$endif} {$ifdef Alpha} Alpha specific stuff {$endif} etc. > On other machines, pointers are different; e.g. on the DEC Alpha, a > pointer has eight bytes. How do I set a pointer to point to the VGA (for example) in a way that can be ported to at least Linux? I'm going to start work again on my game lib (graphics part), and M13h would be a start :) Another thing is how do I modify the contents referenced by the pointer? Writing a byte so it's portable, writing a word so it's portable, etc. My ultimate goal is to port this lib to PMode DOS, Mac, '95, Linux, X, and whatever other platform I can get my grubby hands on, but I'll settle for PMode DOS for now :) > Yes. Provided you use GPC's pointer arithmetic as implemented in > gpc-somewhere-in-may-or-so. Casts to `Word' and such are *not* > portable. Cool :) > It works now. :-) Will check it out! > While the official version of GPC is still 2.0, the latest beta version > ... > patches to gpc-970714 already exist on Agnes, too, but they are no Gee, I wonder why I don't like politics, hmmm :P > official new beta yet. Due to administrative problems :-(some paper war > must be resolved first - sigh)-: I am retaining more recent sources, but > some bug fixes have been posted to this list now and then ... See ya! Orlando Llanes

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Re: gcp on HP-UX 10.20, alpha-dec-osf3.2
by Peter Gerwinski 18 Aug '97

18 Aug '97

Hello! According to John Miller: > > I wrote earlier about problems with gpc making on solaris 2.5 (SunOS 5.5). > [...] > ./xgcc -B./ -DIN_GCC -g -I./include -DNO_MEM (wrapping) > -DNO_LONG_DOUBLE_IO -O0 -I. -c ./enquire.c > [...] This looks as if you are compiling GPC in the same directory where the source is. Did you already try to use a different directory for the source and the objects? Both for GCC and GPC? This is known to fix many problems. Also, recent beta versions of GPC, available at ftp://agnes.dida.physik.uni-essen.de/gnu-pascal/beta/, are known to cause less problems than gpc-2.0 when compiling them on UNIX machines. (And they are more stable anyway.;-) Hope this helps a little, Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [970201] maintainer GNU Pascal [970714] - http://home.pages.de/~gnu-pascal/ [970125]

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Pointer & GPC question...
by Orlando Llanes 18 Aug '97

18 Aug '97

Ok, I know you guys are gonna shoot me for this, but here goes anyway... My question is about Pointers, what I want to know are 3 things.. 1) What is the format of a pointer? Is it 3 bytes (selector--1 byte, base address--2 bytes)? Or is it 4 bytes? 2) If I performed pointer arithmetic that works under MS-DOS, will it also work under Linux without modification? 3) How do I create a generic pointer? Can I just use "Pointer"? reason I ask is because I tried plain Pointer once, and it didn't work. Another question I have now while we're at it, is the latest version of GPC posted on the FTP site? Or is it still in patched versions? I want to upgrade, but I don't want to mess with patches unless I could upgrade from 2.01 Where can I find the upgrade? Thanks in advance! -- See ya! Orlando Llanes

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Re: Enviroment variables
by Achim Kalwa 14 Aug '97

14 Aug '97

Hello! According to Fred: > I'd like to use GPC for some simple CGIs I'm writing for my own server. > >To accomplish this I need to know how to: > >1) Read from various environment variables like $QUERY_STRING. >2) Read from Standard Input. > >Any and all help greatly appreciated. > Here's a litte demo program (i learn best with demo programs :-). It declares the "getenv" function itself and doesn't need any other unit. But there is a "bpcompat" unit for that and a lot of other useful things. {$x+} (* <- Enable extended syntax *) PROGRAM cgi1(Input, Output); TYPE tStr255 = String(255); FUNCTION GetEnv(Name : pChar):pChar; C; (* get access to the getenv funktion in c rtl *) VAR St : tStr255; BEGIN (* write some environment variables *) WriteLn(' TERM : ', GetEnv('TERM')); WriteLn(' SHELL: ', GetEnv('SHELL')); (* now echo all stdin *) WHILE NOT Eof(Input) DO BEGIN ReadLn(Input, St); WriteLn('>>', St); END; END. Hope this helps, Achim

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Gpc August 1997