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GP creates unresolved links when compilation is done using GP
by Igor Marnat 25 Jul '05

25 Jul '05

Hello Peter, >>I have the main program file program.pas, it uses >>a few units unit1.pas, unit2.pas, ... After the compilation process is >>finished, file program.o contains unresolved links to the functions >>init_Unit1, init_Unit2, ... PNL> gp will create each of the .o files for each unit, it PNL> unit1.o, unit2.o, program.o PNL> unit1.o will include the init_Unit1 function. PNL> You then need to link them all together. Well, this is the problem: unit1.o doesn't contain the function init_Unit1. Therefore unresolved link to init_Unit1 in program.o cannot be resolved. This is the difference from program.o compiled with "arm-elf-gpc --autobuild ..." command line. Program.o compiled in such a fashion doesn't contain unresolved link to init_Unit1. The file program.o compiled with "gp PC=arm-elf-gpc ... " does contain the link to init_Unit1 that cannot be resolved. In the both cases the same arm-elf-gpc compiler is used. Regards, Igor Marnat mailto:marny@rambler.ru

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Re: unit dependencies (about GPC compiler internals)
by Igor Marnat 25 Jul '05

25 Jul '05

AvO> There are known problems with --autobuild and --automake. Anyway, since AvO> these options will be deprecated in the near future, try "gp" AvO> (<http://fjf.gnu.de/>) instead. Adriaan, thank you very much! It works ... partially:) It works fine with my native gpc compiler (it is of version "gpc version 20050217, based on gcc-3.4.3"). I'm also forced to use cross compiler (for arm-elf- target). Here is the problem. More detailed: I have the main program file program.pas, it uses a few units unit1.pas, unit2.pas, ... After the compilation process is finished, file program.o contains unresolved links to the functions init_Unit1, init_Unit2, ... Some of the units don't have such a functions. It is the units that don't have the code that is executed on unit initialization time. So these references cannot be resolved and build process stopped with error. Is it possible that the problem is caused by my cross compiler which is a bit old? (my arm-elf-gpc is "gpc version 20030830, based on gcc-3.3.1"). Actually, I'm confused because this very compiler can build the project if it is called in another way. When build process is inited in "arm-elf-gpc --autobuild ..." fashion (an old fashion), there is no program.o file in current directory - compiler builds main program object file in a temporary directory and all works fine (obviously, it doesn't add links to non-existing functions). When build process is inited as "gp PC=arm-elf-gpc ..." (a new fashion), there is program.o file in current directory which contains unresolved links. waiting for any ideas, Regards, Igor Marnat mailto:marny@rambler.ru

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Re: New as function
by Peter N Lewis 25 Jul '05

25 Jul '05

> > Peter N Lewis wrote: > > > Does New as a function return nil or does it still give a runtime error? >> > >> > If I want to allocate memory, but handle it gracefully if it fails, > > > what are the recommended approaches? >You could also trap runtime errors, using `AtExit', or use the >`Trap' unit (which does this internally). This comes somewhat closer >to exception, though it's not quite the same. Indeed, this may be >the best solution available. It's a bit code to write, but it uses >`New' and has no disadvantages in this regard. Ok, it's an interesting approach, but I'd have to write that code for each type, which is still pretty ugly. I just checked, and if New returns nil (using the UndocumentedReturnNil for example), the compiler will blindly try to Initialize the returned data, and bus error. I'm not sure if this counts as a bug, since presumably UndocumentedReturnNil is only suppose to be for BP compatibility, and with BP compatibility there would be no Schema and thus no initialization. Unless perhaps BP has objects, in which case, New(obj) which returned UndocumentedReturnNil would probably have the same bus error issue. It's a shame, as this would be the best solution (documenting UndocumentedReturnNil and allowing GetMem to return it). I'd love to start using New and Schema and such, but the best solution seems to be the Trap technique and that's some ugly code to have any place you want to use New and not crash out. I guess I can stick to using the system NewPtr routine and manually calling Initialize, but that doesn't mesh will with Schema. I did think of another hack, which was to pre-allocate a chunk of memory larger than the largest New command, and then have GetMem return that for failure, then rather than testing for nil, I could test of that safe return value. It's ugly, but probably the simplest solution that provides clean New code. Peter. -- <http://www.stairways.com/> <http://download.stairways.com/>

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Pascal in .ar prisons + xlate Pascal to Spanish
by Nicolas Rosner 25 Jul '05

25 Jul '05

Hi. I just sent an email [see below] to Florian from the Free Pascal team. Then I found out about GNU Pascal, and thought this list might be another good place to ask. Any pointers to i18n or related efforts that could be of any use to us are most welcome. TIA, I look forward to hearing from you, N. ------ Hello! I'm involved in a project called "UBA 22" where we teach basic computer skills to inmates of local (Buenos Aires, Argentina) prisons. It's a difficult task, the penitentiary service tolerates but hardly helps us, state support is scarce, etc. At the prison where I used to teach until recently (SPF U2, "Devoto"), we had five almost-falling-apart 486s and one Pentium 1 or so, for a very high demand of students (nearly 800 interested per term, of which nearly 200 are admitted). We teach the basics, from "what is a computer" to Windows usage, MS Office tools, etc. During the last couple of years I've been thinking about setting up a newer, more advanced course for the few inmates who survive the 3 or 4 basic ones. I'd like to teach a very basic intro to programming. Pascal seems like a decent language for this (there are better options, but each has its own cons [no pun intended]). Anyway, I've been looking for a compiler, but there's a big language problem -- most of our students hardly read or write in Spanish, let alone anything in English. "Begin", "While" and "For" don't mean anything to them. So my aim is to find - a free pascal compiler for DOS, Windows and Linux on Intel hardware - which {already is || can easily be} translated to Spanish where by "translated" I mean - basic language keywords - basic lib elements (nothing very specific, just basic i/o, etc.) - basic compiler and linker output More advanced / obscure stuff might very well be in English. I can translate, I have no problem with that. But I need the right product, a license that allows for this, and any reasonably simple method in order to find the strings and replace them with Spanish equivalents. Do you think FP [GPC] would be a good option? Any input will be very welcome. Thanks a bunch IA & greetings from Buenos Aires. Nicolás Rosner Departamento de Computación Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Argentina

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(no subject)
by Contestcen＠aol.com 24 Jul '05

24 Jul '05

> Does New as a function return nil or does it still give a runtime error? > > If I want to allocate memory, but handle it gracefully if it fails, > what are the recommended approaches? In BP there is a HeapError variable which points to the default error procedure. You can reset it to point to your own error procedure and handle the error however you like. I don't know if this works with other Pascal compilers. Frank Rubin

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Array elements as control variables
by Contestcen＠aol.com 23 Jul '05

23 Jul '05

> done, but I much prefer the loop version to the last version. > > Can't you use a macro processor to generate the verbose code? ;-) Yes, I would use the Pascal Macro Compiler for this chore, but whether I code it by hand or generate using the PMC, my program still would contain the verbose code. > Anyway, I see that this is an example, at least in theory. However, > I'd probably do it differently in practice. I think this is more > efficient, since you don't need any comparisons, and in particular > no extra code in the innermost loop which is the most time-critical. > If you need the original start values afterwards, copy the array > before the first loop, of course. > > for a1 := start[1] to max[1] do > begin > for a2 := start[2] to max[2] do > begin > for a3 := start[3] to max[3] do > begin > ... > end; > start[3] := 1 > end; > start[2] := 1 > end; > > Frank This is much nicer code than my version. However I would still choose to make the loop control variables a[1], a[2], a[3], etc., so that when I take the checkpoint the checkpointing procedure could use a loop like for n := 1 to depth do writeln (checkfile, a[n]); Incidentally, when I do this in practice I do not usually test for interruptions at every level in the nested loops. If the loops are nested 30 levels deep I might test for user interrupts only at levels 5, 10, 15 and 20. However, if the interrupt occurs at, say, level 15, you still need to write all of the control variable values from 1 through 15 to the checkpoint file. Frank Rubin

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Mailing list archive is back
by Frank Heckenbach 23 Jul '05

23 Jul '05

After some time of problems the mailing list archives are back at their usual places: http://www.gnu-pascal.de/crystal/gpc/en/ http://www.gnu-pascal.de/crystal/gpc-announce/en/ http://www.gnu-pascal.de/crystal/gpc-doc/en/ The full GPC web site will be restored next week I hope. Frank -- Frank Heckenbach, frank(a)g-n-u.de, http://fjf.gnu.de/, 7977168E GPC To-Do list, latest features, fixed bugs: http://www.gnu-pascal.de/todo.html GPC download signing key: ACB3 79B2 7EB2 B7A7 EFDE D101 CD02 4C9D 0FE0 E5E8

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GPC and Mac implicit pointer objects
by Waldek Hebisch 23 Jul '05

23 Jul '05

As I wrote I updated may implementation of Delphi classes to gpc-20050331. Now, I have put a patch at: http://www.math.uni.wroc.pl/~hebisch/gpc/delphi3.diff With the patch, when one chooses Mac Pascal as a dialect, object model should be compatible with Mac Pascal: -- objects are pointers -- all methods are virtual (that was already implemented in gpc-20050331) -- overriding a method requires `override' keyword -- you can allocate memory for objects with `New' and deallocate it with `Dispose' In default mode the `class' keyword is recognized and allows you to declare Delphi classes. ATM Delphi constructors works only in simplest case (you can not call a constructor inside a (different) constructor). Destructors do not deallocate memory (but `Dispose' applied to a Delphi class will deallocate memory). Also, Delphi builtin `TObject' is unimplemented. This is experimatal (and incomplete) implementation. I would like to get some feedback about missing features. Also, if I got semantics of implemented parts correctly. ATM I know only about one missing Mac objects feature (which is almost surely due to my lack of knowledge about Mac Pascal): GPC requires all methods to be defined in the same unit as the object (TCL sources implement methods in different units). And of course test programs are welcome. -- Waldek Hebisch hebisch(a)math.uni.wroc.pl

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Update for Mac OS X
by Adriaan van Os 23 Jul '05

23 Jul '05

Updated compiler sources, binaries and patches for Mac OS X can be downloaded from <http://www.microbizz.nl/gpc.html>. Please note that there are separate binary installer packages for Mac OS X 10.3 and Mac OS X 10.4. The distribution is based on gpc-20050331, gcc-3.4.4 and Waldek's MacPascal (& Delphi) object support patches (delphi14.diff). Regards, Adriaan van Os

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New as function
by Peter N Lewis 22 Jul '05

22 Jul '05

Does New as a function return nil or does it still give a runtime error? If I want to allocate memory, but handle it gracefully if it fails, what are the recommended approaches? Thanks, Peter. -- <http://www.stairways.com/> <http://download.stairways.com/>

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