syscall/js.stringVal receives negative value as an arg

[egawata]

I encountered an error with DataView while developing WebAssembly app.
This is a message in DevTool's Console tab of Chrome browser.

wasm_exec.js:236 Uncaught RangeError: Start offset -2093352176 is outside the bounds of the buffer
    at new DataView (<anonymous>)
    at loadString (wasm_exec.js:236:27)
    at syscall/js.stringVal (wasm_exec.js:313:17)
    at main.syscall/js.ValueOf (wasm.wasm:0x12a21)
    at main.(:8088/syscall/js.Value).Set (http://localhost:8088/wasm.wasm)
    at main.(:8088/*main.hoge).incr$bound (http://localhost:8088/wasm.wasm)
    at main.runtime.resume$1 (wasm.wasm:0xe268)
    at main.runtime.resume$1$gowrapper (wasm.wasm:0x94af)
    at main.tinygo_launch (wasm.wasm:0x4e8)
    at main.runtime.scheduler (wasm.wasm:0x95b4)

Environment

• OS: macOS Sequoia 15.3.1
• go version go1.23.1 darwin/arm64
• Google Chrome 133.0.6943.142（Official Build） （arm64）

$ tinygo version
tinygo version 0.36.0-dev-056394e2 darwin/arm64 (using go version go1.23.1 and LLVM version 19.1.7)

To reproduce the error

Assuming using Chrome web browser.

• Clone my sample repository.
  • egawata/tinygo_dataview_error
• Build and run HTTP server.

# Build
cp "$(tinygo env TINYGOROOT)/targets/wasm_exec.js" ./wasm_exec.js
GOOS=js GOARCH=wasm tinygo build -o wasm.wasm ./main.go

# Run HTTP Server
go run localserver/server.go

• Open http://localhost:8088 on your browser.
• Open DevTools and switch to Console tab.
• Push Run Button several times.
• After pushing button 22 times or so, an error message like the above will appear.

Maybe the amount of memory exceeds upper limit of int32 (2_147_483_648 bytes), and value_ptr in the first arg of syscall/js.stringVal becomes negative (unexpected) value.

One solution is to convert the value to unsigned. It solved the problem in my environment.

#4764

cf. misc/wasm: make sure sp is unsigned · golang/go@9848e93

[deadprogram]

Closed as part of v0.36.0