WebAssembly/Compiler
Instructions
Prerequisites
The llvm-mc assembler and wasm-ld linker. These are the assembler and linker from the LLVM project.
Obtaining the compiler sources
Get the sources:
svn checkout https://svn.freepascal.org/svn/fpc/branches/wasm/ fpc-wasm
enter the directory:
cd fpc-wasm
Supported targets
WASI target
make all OS_TARGET=wasi CPU_TARGET=wasm32 BINUTILSPREFIX= OPT="-O-" PP=fpc
Currently, it reaches the point, where it fails with this error:
globals.pas(40,7) Fatal: Can't find unit sysutils used by globals Fatal: Compilation aborted
This is because the sysutils hasn't been ported to the WASI target, yet. If compilation reaches this point, you can still compile 'Hello, world!'. The following units have been ported for the WASI target:
- system
- objpas
- ctypes
- strings
- wasiapi - interface for the WASI API
Embedded target
make all OS_TARGET=embedded CPU_TARGET=wasm32 BINUTILSPREFIX= OPT="-O-" PP=fpc
Using the compiler
Hint: If your fpc.cfg has
#IFDEF FPC_CROSSCOMPILING #IFDEF NEEDCROSSBINUTILS -XP$FPCTARGET- #ENDIF #ENDIF
Enclose it in #IFNDEF CPUWASM32 :
#IFDEF FPC_CROSSCOMPILING #IFDEF NEEDCROSSBINUTILS #ifndef cpuwasm32 -XP$FPCTARGET- #endif #ENDIF #ENDIF
Otherwise, you have to create symlinks wasm-wasm-wasmld to wasmld, and wasm-wasm-wasmtool to wasmtool.
wasm-demo
Wasm-demo is a Pascal WebAssembly demo project, ported Google's C WebAssembly example (https://codelabs.developers.google.com/codelabs/web-assembly-intro)
You follow these steps in order to get the demo project working:
1. Get the project sources: https://github.com/skalogryz/wasm-demo
Using in webassembly.studio
2. Run the wasm compiler against lyff.pas, but request the assembler file to be kept
pp -a lyff.pas
Webassembly.studio accepts the assembler file and would compile it on the server side.
3. open up https://webassembly.studio and select "Create empty Wat Project". The project will consist of:
- main.html
- main.js
- main.wat
All files of the project can be edited through the web interface.
4. Copy and paste the contents of the following files:
- (compiled) lyff.wat to main.wat.
- wasm-demo\webassembly.studio\main.html to main.html
- wasm-demo\webassembly.studio\main.js to main.js
Note: every time you copy and paste, don't forget to press "SAVE" button (on the right side of the web interface)
5. once all files are update, hit "Build and Run"