WASM roadmap

[certik]

ASR->WASM backend: (ASR features that have to be implemented):

• WASM: structs and pointers #1484
• Get generics template examples working with WASM lfortran/lfortran#1294
• WASM: one array generics example does not work lfortran/lfortran#1332
• WASM: complex numbers #1519
• Support arrays / numpy in WASM #1483 (later)

WASM->x86

• WASM->x86: add support for global variables #1539
• WASM: malloc #1540
• WASM_x64: create object files #1541

Refactoring

• WASM: Runtime Library #1413
• Simplify WASM assembler lfortran/lfortran#589 (later)
• WASM: give an error message if sections are in wrong order #1486 (later)
• Overflow during printing floats in the wasm backend lfortran/lfortran#1331

Other:

• Add menu to select examples to run lfortran/lcompilers_frontend#59
• Ensure the WASM output is compatible with wasmtime + WASI #1461
• Merge WASI support lfortran/lcompilers_frontend#64 on February 25.
• WASM: compile modern Minpack into WASM and x64 lfortran/lfortran#1242 (requires to compile to ASR first, and arrays and runtime library)
• Online GUI: Have multiple "preinstalled" programs lfortran/lcompilers_frontend#8
• Jupyterlite: Jupyterlite plan lfortran/lfortran#927
• dev.lfortran.org: use Release build lfortran/lfortran#1240
• Add WASM->arm/M1/MachO backend

Done:

• WASM: Runtime Library Experiment #1425
• WASM to X86 Backend #1222
• WASM, WASM_X64: Support shift operations #1482

[certik]

A good high level goal to "finish" the WASM effort is to take some code like Minpack or equivalent and get it compiling via WASM and get it working via wasmtime as well as in the browser.

We can do a progression of programs:

• examples/expr2.f90
• something intermediate (LPython or LFortran)
• Minpack

For all these, the following should work:

• lfortran --backend=wasm examples/expr2.f90 -o expr2.wasm and wasmtime expr2.wasm as well as running in the browser
• lfortran --backend=wasm_x64 examples/expr2.f90 -o expr2