Hello,
I'm glad to anncounce that FPC now covers working with webassembly in the
browser.
Sounds great. I did a quick compile for the wasi target and seemed to work fine with a simple helloworld-style test. So i decided to try and port a game i made last year[0] - initially made for an MS-DOS game jam, but added a bunch of ports later and wanted to make a web-based one too.
I decided to go with a similar approach to the one i used for Android, with the game compiled into a library (or a wasm file for here) and a "stub" that loads the library and passes events, etc to it.
However no matter what i try, it always seems to fail when (i guess) tries to link or assemble the first unit (the unit doesn't do anything, just defines an entity class).
By default it gets this error which happens after it compiles everything (SndEmit.o is the object file for the unit, it is just the first unit it tries to link/compile):
wasm-ld: error: ./Engine/SndEmit.o: invalid relocation function index Error: Error while linking
If i pass -Awabt to use the wasa assembler (thinking that there might be something wrong with the object files), it then has the error:
SndEmit.pas(171) Fatal: Internal error 2019093001
(The unit is 171 lines long)
Also there are a bunch of "steam read error" errors, often after "assembling someunitname" (though not all "assembling someunitname" have such an error after them).
If i pass -Allvm-mc to use LLVM's assembler, i get a bunch of errors from a different unit (Misc):
Compiling ./Engine/Misc.pas
Assembling misc
./Engine/Misc.wat:5082:3: error: symbol
MISC$_$TSTRINGKEYVALUESET_$__$$_INDEXOFKEY$ANSISTRING$$LONGINT missing .functype
call
MISC$_$TSTRINGKEYVALUESET_$__$$_INDEXOFKEY$ANSISTRING$$LONGINT ^
./Engine/Misc.wat:5412:3: error: symbol
MISC$_$TSTRINGKEYVALUESET_$__$$_INDEXOFKEY$ANSISTRING$$LONGINT missing .functype
call
MISC$_$TSTRINGKEYVALUESET_$__$$_INDEXOFKEY$ANSISTRING$$LONGINT ^
./Engine/Misc.wat:5606:3: error: symbol
MISC$_$TSTRINGKEYVALUESET_$__$$_INDEXOFKEY$ANSISTRING$$LONGINT missing .functype
call
MISC$_$TSTRINGKEYVALUESET_$__$$_INDEXOFKEY$ANSISTRING$$LONGINT ^
./Engine/Misc.wat:6023:3: error: 3 superfluous return values end_function
^
./Engine/Misc.wat:6272:3: error: 1 superfluous return values end_function
^
./Engine/Misc.wat:6496:3: error: 1 superfluous return values end_function
^
./Engine/Misc.wat:6681:3: error: 1 superfluous return values end_function
^
Misc.pas(150) Error: Error while assembling exitcode 1
Note that i have LLVM 13 installed but also tried removing it and installing LLVM 11 and didn't make any difference. Also FWIW i'm calling the ppcrosswasm32 executable directly and have it installed in ~/Apps/fpc, though it shouldn't make a difference (and the simple hello world code compiled anyway so the compiler setup should be fine).
Is there anything i am missing/not setting up correctly (e.g. i didn't tried with the "embedded" target - i tried to build FPC with it first but got some errors so i didn't explore further and went with "wasi" instead that seemed to work)? AFAIK i do not use any of the functionality that isn't implemented in the Roadmap page in the wiki.
Kostas
[0] https://bad-sector.itch.io/post-apocalyptic-petra
