Failure to build standalone executable in v7.6.4

[jal-frezie]

Testing in an aarch64 machine running Ubuntu Bionic. My testmain.pl is:

main :- format_to_chars("A ~w can be anything", [1234], Foostr), write(Foostr), nl.

This file can be consulted from the prompt, and outputs a list of character codes when main() is called. I attempt to build a standalone executable for it by going

swipl --traditional --goal=main --stand_alone=true -o xssimile -c testmain.pl

...and the following messages appear: ERROR: /usr/lib/swi-prolog/library/qsave.pl:460:7: Syntax error: Operator expected % autoloading prolog_codewalk:must_be/2 from /usr/lib/swi-prolog/library/error % autoloading oset:reverse/2 from /usr/lib/swi-prolog/library/lists % autoloading prolog_debug:backtrace/1 from /usr/lib/swi-prolog/library/prolog_stack % autoloading qsave:current_foreign_library/2 from /usr/lib/swi-prolog/library/shlib % autoloading record:member/2 from /usr/lib/swi-prolog/library/lists % autoloading prolog_codewalk:portray_clause/1 from /usr/lib/swi-prolog/library/listing % autoloading prolog_codewalk:clause_info/4 from /usr/lib/swi-prolog/library/prolog_clause % autoloading prolog_codewalk:initialization_layout/4 from /usr/lib/swi-prolog/library/prolog_clause % autoloading error:assertion/1 from /usr/lib/swi-prolog/library/debug % autoloading user:format_to_chars/3 from /usr/lib/swi-prolog/library/charsio % autoloading prolog_codewalk:clause_name/2 from /usr/lib/swi-prolog/library/prolog_clause % Autoloader: iteration 1 resolved 11 predicates and loaded 11 files in 0.445 seconds. Restarting ... % Autoloader: loaded 11 files in 2 iterations in 0.614 seconds ERROR: atomics_to_string/2: Type error: text' expected, found[126,119,61]' (a list)

No executable is produced. Consulting the file /usr/lib/swi-prolog/library/qsave.pl at the prompt does not produce errors. To produce the atomics_to_string/2 error at the prompt, the 1st arg has to be a list containing the sublist `[126,119,61]' . The same example works OK producing a good executable in Swipl 6.6.6 on armv7l machine running Debian Jessie, and in Swipl 7.2.3 on an x86-64 machine running Debian Stretch.

[JanWielemaker]

7.6.4 is very old and --traditional causes a lot of things to malfunction. That is only intended for people who expect a very basic and as much as possible compatible version. Try drop that first. Else upgrade.

[jal-frezie]

Just tried on Swipl 8.0.1, and it appears the --traditional option is gone. This is a pain, because I have a large volume of legacy code that would take a lot of work to translate to modern, especially as I want to keep compatibility with GNU-Prolog. Looks like I am going to have to support the armv7l and aarch64 platforms by using older versions of Swipl.

[JanWielemaker]

? A little test shows that basic -traditional is still there. Just, more and more parts of the system rely SWI 7 features and thus stop to work with -traditional.

But, SWI 7 is designed to run 99.9% of ISO code. Only a few things to not work, but for those there are alternative constructs that both work in ISO and SWI 7. You might need

:- set_prolog_flag(double_quotes, codes).

If you think otherwise, please show the code that causes problems without -traditional.

[jal-frezie]

OK, I was getting confused by the error message from Swi 8.0.1, which was:

jaspert$ swipl --traditional --goal=main --stand_alone=true -o xssimile -c testmain.pl ERROR: /Applications/SWI-Prolog.app/Contents/swipl/library/qsave.pl:677:7: Syntax error: Operator expected ERROR: save_option `traditional' does not exist

Looks like the error I reported is still there, plus others. Regarding doing without --traditional, it looks like I have to put the directive :- set_prolog_flag(double_quotes, codes). into every module, and also call it as a predicate before doing term I/O with quoted strings -- or is there an easier way?

[JanWielemaker]

I think it should be enough to put an :- set_prolog_flag(double_quotes, codes). at the start of testmain.pl to get it all compiled correctly and an :- initialization set_prolog_flag(double_quotes, codes). to get the runtime behaviour to work. Note that the chapter on SWI 7 extensions provides a quite in depth discussion on how to handle strings and how to debug string issues.

[jal-frezie]

OK, I was able to put the directive in every module since the module declarations themselves were inserted by term expansion, so I just tweaked that to include the directive as well. Now I have the problem that infix operators in single quotes do not work outside traditional mode (except if the quotes are needed to stop the operator being a variable!). For instance... $ swipl --traditional ... ?- op(550, xfy, and). true.

?- P = a 'and' b. P = a and b.

?- % halt $ swipl ... ?- op(550, xfy, and). true.

?- P = a 'and' b. ERROR: Syntax error: Operator expected ERROR: P = a ERROR: here ERROR: 'and' b . ?-

Is there another declaration to fix this? Happy to take discussion elsewhere if appropriate.

[JanWielemaker]

The rule is, following ECLiPSe, if the operator does not need quotes, quoting it prevents it from being an operator. Otherwise, e.g., :- op(100, yf, 'Gb')., quoting is ok: 100'Gb'.

So, all you need to do is get rid of the quotes around e.g. 'and'. That should still work on any ISO compliant system.

The mailinglist/forum is a more appropriate place. I guess we are (almost) done though.