Gpc October 1998

gpc@gnu.de

24 participants
42 discussions

Re: Code Gen Prob -- Retraction...
by Frank Heckenbach 12 Oct '98

12 Oct '98

Orlando Llanes wrote: > There is one thing tho, it seems > that variables declared within the program are not properly exported > outside of the source module. I attatched a simple example program to show > what I mean. This seems to be a bug in fact. They are declared "local" in the assembler output (or shouldn't they be global for some reason, Peter?). The following program can even test this in Pascal. Frank -- Frank Heckenbach, frank(a)fjf.gnu.de http://fjf.gnu.de/ PGP and GPG keys: http://fjf.gnu.de/plan program orland2; uses orland2u; var bar : string (10); begin bar := 'failed'; baz; writeln (bar) end. unit orland2u; interface procedure baz; implementation var bar : external string(10); procedure baz; begin bar := 'OK' end; end.

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libgtk-use in gpc-pascal-programs under linux
by Mike Neuhaus 11 Oct '98

11 Oct '98

Hallo,...... ......i want to use the libgtk for my gpc-pascal-programs. for this i search an unit/module, that implements the gtk-library. Who can help me? thanks and cu Mike -- http://ekim.home.pages.de Mike Neuhaus ********PRO Heimerziehung heit PRO Zukunft********** Die Heimerziehung bedarf nicht ihrer eigenen Abschaffung,sondern einer durch Innovation geprgten Reform m

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Re: Code Gen Prob -- Retraction...
by Frank Heckenbach 11 Oct '98

11 Oct '98

Orlando Llanes wrote: > Before I begin, the reason I didn't notice this at first is because > the previous version of GPC compiled my program without a problem despite > the following... I use external assembly routines that access variables > declared in a Pascal unit (the assembler doesn't matter, it happens with > both AS and NASM). To declare the variables defined in the Pascal unit, I > declared them "common". Then I changed all "common" references to global > references and added declarations in the .data section and the program no > longer crashed. Weird. Fine to hear so. However, did you find out what the previous GPC did differently so the problem did not occur? If you still have that version installed, can you compare the -S output of the previous and the current GPC version to see what's different? (Just to be sure it really isn't a code generation problem...) Frank -- Frank Heckenbach, frank(a)fjf.gnu.de http://fjf.gnu.de/ PGP and GPG keys: http://fjf.gnu.de/plan

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Code Gen Prob -- Retraction...
by Orlando Llanes 10 Oct '98

10 Oct '98

Argh! I can't believe how extremely simple the mistake was!!! A while back I reported that my program crashed after compiling with the latest version of GPC. I finally figured out why! Before I begin, the reason I didn't notice this at first is because the previous version of GPC compiled my program without a problem despite the following... I use external assembly routines that access variables declared in a Pascal unit (the assembler doesn't matter, it happens with both AS and NASM). To declare the variables defined in the Pascal unit, I declared them "common". Then I changed all "common" references to global references and added declarations in the .data section and the program no longer crashed. Weird. Thanks for your help Frank! See ya! Orlando Llanes "Meine Damen und Herren, Elvis hat soeben das Gebaeude verlassen!" "Look out fo' flyeeng feet" O__/ a010111t(a)bc.seflin.org \/|____. O <__. \/\> / \ ____________|___\______ http://ourworld.compuserve.com/homepages/Monkey414

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RE: gnu-pascal compiler for Delphi?
by Andreas Prucha [helicon] 10 Oct '98

10 Oct '98

>Delphi is basically a Windows-version of Pascal. Made also by borland, >it should work. The last text version of Pascal from Borland that I hvae >is7.0 which was object oriented, and pre-windows. Delphi came out as the >next version. Yep, but Delphi's Object Pascal has a lot of extensions over TP7. For example a redesigned class-model with RTTI and properties, exception handling and so on. Thus, the usual Delphi program won't compile on TP7-compatible compiler. Delphi got a lot of extension. Andreas

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Re:
by Alec Cawley 09 Oct '98

09 Oct '98

In article <907967940.209538.0(a)tvweb1.hiway.co.uk>, writes >Andreas Prucha [helicon] wrote: >> >> Yep, but Delphi's Object Pascal has a lot of extensions over TP7. For >> example a redesigned class-model with RTTI and properties, [...] > >RTTI? What's that? ?Run Time Type Identification? -- Alec Cawley

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gnu-pascal compiler for Delphi?
by Thomas Keller 09 Oct '98

09 Oct '98

Hi there I have problem with my Delphi application. I want to compile it under Linux. Do you know if gnu-pascal supports the Delphi language? Or exist any other ways to translate it first to C or Pascal? Thanks for your help Regards Thomas

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success: newbi-problem
by Mike Neuhaus 08 Oct '98

08 Oct '98

thanks for the Tip. The libc6 - version of the gpc works fine on my debian2.0. cu -- http://ekim.home.pages.de Mike Neuhaus ********PRO Heimerziehung heißt PRO Zukunft********** Die Heimerziehung bedarf nicht ihrer eigenen Abschaffung,sondern einer durch Innovation geprägten Reform

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I want to subscribe. Help
by Alfredo Cesar Fontana 08 Oct '98

08 Oct '98

Hello there, I want to subscribe this mailing list. I program in Turbo Pascal 7.0. I met DJGPP, and then the GPC 2.0(2.7.2.1). I want to migrate there. But I have some problems. Also, I can contribute, if it is posible. I want to know how to meet people who are in similar situation. Sorry my english is poor. Thanks. Alfredo Buenos Aires ARGENTINA

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Re: ref string bug
by Frank Heckenbach 08 Oct '98

08 Oct '98

Russ Whitaker wrote: > tried program by Jo Dillon > > changing the function GetMem to the procedure GetMem makes the problem go > away > > why i don't know (* See my previous mail for the description of the problem. *) When using the GetMem procedure, GPC seems to initialize the Capacity field. However, this is a misfeature, and needs to be turned off! Sorry if that's unpopular, but here's the reason why: when the record contains a string (or any schema) in any position but the first, and the size requested from GetMem is smaller than the size of the fields before, the discriminants (here: Capacity) will be outside the allocated space, and must not be written to. The following version of the program demonstrates the problem. It will just allocate enough space for the first string (s), which would be sufficient for what the program does here. However, GPC's trying to initialize t and u will go outside the allocated memory -- I increased the size of the strings here, so that this will most likely result in a segfault. program baby; type BigString = String(200000); type trec = record s, t, u : bigstring; end; prec = ^trec; var r : prec; begin GetMem(r, sizeof(bigstring)); r^.s := 'OK'; writeln (r^.s) end. The bottom line here is that GetMem (as well as FillChar, for that matter) are low-level routines, and mixing them with (high-level) Pascal objects like schemata (e.g. Strings) or files, requires precise understanding of the internals, is non-portable (between compilers as well as between architectures) and should be avoided (here: by using New) whenever possible. It might even be worthwhile to think about disabling GetMem etc. by default to protect against such bugs, and enabling them only with a special switch (something like a "weaker `--extended-syntax'") and, of course, in `--borland-pascal'. Now the good news as far as strings are concerned: BP compatible "short strings" are on the To-Do list, and when they will have been implemented, whenever this will be, such things like GetMem, even `GetMem (StringPtr, Length (StringVal) + 1); StringPtr^ := StringVal', FillChar, or accessing `StringVar [0]' to get and/or modify their length, will work with short strings, as they won't have a Capacity field. Frank -- Frank Heckenbach, frank(a)fjf.gnu.de http://fjf.gnu.de/ PGP and GPG keys: http://fjf.gnu.de/plan

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Gpc October 1998