Gpc

gpc@gnu.de

5400 discussions

Re: Problems with file-handling an new GPC Beta
by Peter Gerwinski 08 Oct '97

08 Oct '97

According to Jesper Lund: > > You need to close the file before calling reset. If you add > > close(f) > > just before > > reset(f) > > your program works fine. Whether this is a *feature* or a *bug* depends on > the definitions of reset/rewrite in the (various) Pascal standard(s). [...] I agree. However when we want to claim some compatibility to Borland Pascal, GPC must also support this feature/bug. So I must consider this failure a bug in GPC. Thanks, Christian, for finding it out! :-) Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [971005] maintainer GNU Pascal [971001] - http://home.pages.de/~gnu-pascal/ [971005]

1 0

Re: "Segment fault" error :-(
by Peter Gerwinski 08 Oct '97

08 Oct '97

According to Christian Bockermann: > chris@bockermann:/home/chris/programs/pascal/indent > a.out > Segmentation fault This means that you have written to some memory where you were not allowed to write to. In this case it means that you have filled the string beyond its capacity. Let's see why: > program test; > > type tstr = string[30]; > > var s_test : tstr; > > function copy (s : tstr; p1 : integer; p2 : integer ) : tstr; (* Here you can save some typing by writing "p1, p2: Integer". *) > var > i : integer; > buf : tstr; > begin > for i:=p1 to p2 do What you mean is: "for i:= p1 to p2 + p1 do". > buf[i]:=s[i]; > copy:=buf; Here is the problem: You have assigned some characters to the string, but not a length. Now, "copy:= buf" assigns a string of *random* length to the variable `buf' with a capacity of 30 which causes the crash. > end; > > begin > s_test:='Dies ist ein Test-string'; > writeln(copy(s_test,5,4)); > end. To solve the problem you can either directly assign a length to the string - which is currently only possible by using some more-or-less dirty tricks - or you do it this way: buf:= ''; for i:= p1 to p1 + p2 do buf:= buf + s [ i ]; copy:= buf; BTW (= by the way), your procedure does not check whether `p1 + p2' or even `p1' is in the range of the string `S'. > (By the way, if you have suggestions for a better style of programming > this copy-function, please let me know, I'm already learning ... :-) You mean: You are *still* learning. :-) No problem with this - your style is very good. I have seen a much worse programming style from people who consider themselves "computer freaks". (I may say it here because noone of them is on this list (hopefully).;-) Good luck, Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [971005] maintainer GNU Pascal [971001] - http://home.pages.de/~gnu-pascal/ [971005]

1 0

Re: Problems Building Latest GPC Beta
by Peter Gerwinski 08 Oct '97

08 Oct '97

According to Phil Robertson: > Has anyone seen or have any ideas about this problem with > building the latest Beta: > [...] > include/string.h:127: conflicting types for `perror' > include/errno.h:54: previous declaration of `perror' This looks like broken system header files for me. Sorry, but I have no better suggestion than to look into those header files and see why the declarations conflict. Good luck, Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [971005] maintainer GNU Pascal [971001] - http://home.pages.de/~gnu-pascal/ [971005]

1 0

Re: New GPC beta: gpc-971001
by Peter Gerwinski 08 Oct '97

08 Oct '97

According to Maurice Lombardi: > > There is another error in this initialization part (which presumably has > nothing to do with the crash of the compiler). > The variable ppJunk is New'ed, used to fill CmdLine, which is a pointer > of pChar type, Then Dispose'd. So the memory to which CmdLine points is > reputted into the heap, and can be overwrited by subsequent instructions > in the main program. This is an error in `system.pas', not in GPC, so I can relax. :-) (* But it's easy to fix: Just remove the line `Dispose ( ppJunk )'. *) Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [971005] maintainer GNU Pascal [971001] - http://home.pages.de/~gnu-pascal/ [971005]

1 0

"Segment fault" error :-(
by chris＠bockermann.ping.de 08 Oct '97

08 Oct '97

Hello again ! My problems with file handling are all solved - thanks a lot, but as I continue working on my program I get another error message. I wrote an extract from my program, which causes the error : program test; type tstr = string[30]; var s_test : tstr; function copy (s : tstr; p1 : integer; p2 : integer ) : tstr; var i : integer; buf : tstr; begin for i:=p1 to p2 do buf[i]:=s[i]; copy:=buf; end; begin s_test:='Dies ist ein Test-string'; writeln(copy(s_test,5,4)); end. I just wanted to implement the string-function "copy" from Borland Pascal to use it on my Linux-System. The error messages I get is : chris@bockermann:/home/chris/programs/pascal/indent > a.out Segmentation fault Does anybody know this problem ? (By the way, if you have suggestions for a better style of programming this copy-function, please let me know, I'm already learning ... :-) Thanks, Chris e-mail > chris(a)bockermann.ping.de ____________________________________ (subject "send pgp-key" for pgp-key)

1 0

Re: New GPC beta: gpc-971001
by Peter Gerwinski 08 Oct '97

08 Oct '97

According to Maurice Lombardi: > > - The test\extended\time.pas works OK with the bash shell, but is broken > with ordinary command.com DOS shell (or Win3.11 DOS box): [...] I cannot reproduce this. :-( > - more important: when trying to compile the unit System.pas contained > in BPcompat 1.0 I get a SIGSEGV error, [...] Frank has tracked down this error to the following: : : unit system; : interface : implementation : : var junk:integer; : : to begin do : for junk := 1 to 1 do; : : end. (Vielen Dank, Frank!) ... so I will be able to hunt it now. :-) Peter Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer peter.gerwinski(a)uni-essen.de - http://home.pages.de/~peter.gerwinski/ [971005] maintainer GNU Pascal [971001] - http://home.pages.de/~gnu-pascal/ [971005]

2 1

Re: New GPC beta: gpc-971001
by Frank Heckenbach 08 Oct '97

08 Oct '97

Maurice Lombardi wrote: > There is another error in this initialization part (which presumably has > nothing to do with the crash of the compiler). > The variable ppJunk is New'ed, used to fill CmdLine, which is a pointer > of pChar type, Then Dispose'd. So the memory to which CmdLine points is > reputted into the heap, and can be overwrited by subsequent instructions > in the main program. Unfortunately, there are similar bugs (at least) in the functions Str2PChar (in System.pas) and Int2PChar (GPCUtil.pas). I hope they will be fixed in the next release. -- Frank Heckenbach, Erlangen, Germany heckenb(a)mi.uni-erlangen.de http://home.pages.de/~fjf/links.htm

1 0

Re: GUIs for GPC
by Frank Heckenbach 08 Oct '97

08 Oct '97

The African Chief wrote: > >Is this system-dependent stuff for Linux free software? > >If so, where can I get it? > > I believe (I may be wrong) - that the complete Turbo Vision > port for DJGPP is supplied as part of the RHIDE sources. > So, all you may need to download is rhide14s.zip Yes, seems to be there, thanks! Perhaps this helps to make some system dependent stuff portable, at least to Linux. -- Frank Heckenbach, Erlangen, Germany heckenb(a)mi.uni-erlangen.de http://home.pages.de/~fjf/links.htm

1 0

Problems with file-handling an new GPC Beta
by chris＠bockermann.ping.de 08 Oct '97

08 Oct '97

Hello all there ! To test the new Beta-Version of GPC I wrote a little program like this : program test; var i : integer; f : FILE of integer; begin assign(f,'./test.dat'); rewrite(f); for i:=1 to 10 do write(f,i); reset(f); while not (eof(f)) do begin read(f,i); writeln(i); end; close(f); end. When compiling there's no error or anything and it compiles quite nice, but when running my program I get a message like this : chris@bockermann:/home/chris/programs/pascal > ./test ?Gpc: `Reset', SeekUpdate' or `SeekRead' to nonexistent internal file `F' What did I do wrong ? Can anybody help me ? Thanks a lot ! Chris e-mail > chris(a)bockermann.ping.de ____________________________________ (subject "send pgp-key" for pgp-key)

3 2

Re: New GPC beta: gpc-971001
by The African Chief 08 Oct '97

08 Oct '97

On Wed, 08 Oct 1997 11:58:25 -0700 Maurice Lombardi <Maurice.LOMBARDI(a)ujf-grenoble.fr> wrote: >Peter Gerwinski wrote: >> Frank has tracked down this error to the following: >> : >> : unit system; >> : interface >> : implementation >> : >> : var junk:integer; >> : >> : to begin do >> : for junk := 1 to 1 do; >> : >> : end. > >There is another error in this initialization part (which presumably has >nothing to do with the crash of the compiler). >The variable ppJunk is New'ed, used to fill CmdLine, which is a pointer >of pChar type, Then Dispose'd. So the memory to which CmdLine points is >reputted into the heap, and can be overwrited by subsequent instructions >in the main program. Oops! I will correct this in the next release of bpcompat, either by disposing of ppJunk in the finalisation part of the unit, or by doing something else! Thanks for the report! Best regards, The Chief Dr Abimbola A. Olowofoyeku (The African Chief, and the Great Elephant) Author of: Chief's Installer Pro v4.01 for Win16 and Win32. Homepage: http://ourworld.compuserve.com/homepages/African_Chief/ E-mail: laa12(a)keele.ac.uk

1 0

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

1996

1995

Gpc