freeship-plus-in-lazarus VS FreePascal

> Many people using Delphi back in the day will probably already know Lazarus

If there is someone who interested in Lazarus, Qt and 2D/3D CAD software, here is an opensource boat (not only) design & simulation software project which was rewritten from Delphi.[0,1,2]

[0] https://github.com/markmal/freeship-plus-in-lazarus

[1] http://web.archive.org/web/20160128212152/http://hydronship....

[2] https://sourceforge.net/projects/freeship

An extended fork of FREE!ship[0] (abandoned since 2007), FREE!ship Plus[1] was ported from Delphi to Lazarus/FPC & Qt since 2015 and actively maintained till October 2020.[2,3]

Author of original opensource FREE!ship switched to develop its proprietary variant, DELFTship, which still actively maintained.[3]

[0] https://sourceforge.net/projects/freeship/

[1] http://web.archive.org/web/20160831005653/http://www.hydrons...

[2] https://sourceforge.net/projects/freeship-plus-in-lazarus/

[3] https://github.com/markmal/freeship-plus-in-lazarus

[4] https://www.boatdesign.net/threads/free-ship-continues-as-de...

> Thanks for the hints. I was already concerned that I would have to analyze the source code directly myself, and so I started to build tools for this purpose (https://github.com/rochus-keller/FreePascal).

FWIW you may want to check out the fcl-passrc package[0] which provides units for scanning and creating a syntax tree from FPC source code, including some helpers like resolving references.

It is used by the fpdoc documentation generator and the pas2js transpiler that converts Free Pascal source code to JavaScript, both official FPC projects. fcl-passrc is itself part of Free Pascal.

> I read somewhere that there are issues with higher optimization levels. Can you confirm that?

AFAIK the main issue is that -O4 enables some optimizations that may break code that relies on things like having the exact same math output as non-optimized versions as it enables FASTMATH, code that relies on classes having specific field order (technically class field order is not guaranteed to remain the same) since -O4 enables reordering the fields to remove unnecessary padding and code that depends on runtime errors or exceptions being thrown from code that the compiler (in -O4) decided it has not explicit side effects and removed it.

These are not "issues" per-se but Lazarus labels -O4 as having "aggressive optimizations, beware" which might give a false impression.

Aside from that there might be bugs, but that is the case with any compiler.

[0] https://wiki.freepascal.org/fcl-passrc