HEAPU8 - Cannot read properties of undefined (reading 'set')

[paulocoutinhox]

Hi,

After update my emsdk to 4.0.7 i get this error:

❯ tests/unit/client.spec.ts  (12 tests | 3 failed) 52ms
   ❯ tests/unit/client.spec.ts > Client > transfer data view
     → Cannot read properties of undefined (reading 'set')
   ❯ tests/unit/client.spec.ts > Client > transfer data view with await
     → Cannot read properties of undefined (reading 'set')
   ❯ tests/unit/client.spec.ts > Client > receive data view with await
     → Cannot read properties of undefined (reading 'buffer')
 ✓ tests/unit/pages.spec.ts  (1 test) 28ms

⎯⎯⎯⎯⎯⎯⎯ Failed Tests 3 ⎯⎯⎯⎯⎯⎯⎯

 FAIL  tests/unit/client.spec.ts > Client > transfer data view
TypeError: Cannot read properties of undefined (reading 'set')
 ❯ Function.createFromArrayBuffer src/xplpc/type/data-view.ts:21:31
     19|         // eslint-disable-next-line
     20|         // @ts-ignore:next-line
     21|         XPLPC.shared().module.HEAPU8.set(data, ptr);
       |                               ^
     22| 
     23|         return new XDataView(ptr, size);
 ❯ tests/unit/client.spec.ts:105:36

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/3]⎯

 FAIL  tests/unit/client.spec.ts > Client > transfer data view with await
TypeError: Cannot read properties of undefined (reading 'set')
 ❯ Function.createFromArrayBuffer src/xplpc/type/data-view.ts:21:31
     19|         // eslint-disable-next-line
     20|         // @ts-ignore:next-line
     21|         XPLPC.shared().module.HEAPU8.set(data, ptr);
       |                               ^
     22| 
     23|         return new XDataView(ptr, size);
 ❯ tests/unit/client.spec.ts:132:36

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[2/3]⎯

 FAIL  tests/unit/client.spec.ts > Client > receive data view with await
TypeError: Cannot read properties of undefined (reading 'buffer')
 ❯ Function.createUint8ArrayFromPtr src/xplpc/type/data-view.ts:29:[53](https://github.com/xplpc/xplpc/actions/runs/14489073689/job/40641117737#step:12:54)
     27|         // eslint-disable-next-line
     28|         // @ts-ignore:next-line
     29|         return new Uint8Array(XPLPC.shared().module.HEAPU8.buffer, ptr…
       |                                                     ^
     30|     }
     31| 
 ❯ tests/unit/client.spec.ts:224:40

My flags:

set(XPLPC_WASM_LINKER_FLAGS "--bind -sMALLOC=emmalloc -sWASM_BIGINT=1 -sALLOW_MEMORY_GROWTH=1 -fwasm-exceptions -sMODULARIZE=1 -sEXPORT_ES6=1 -s \"EXPORTED_FUNCTIONS=['_malloc', '_free']\"")

Ref: https://github.com/xplpc/xplpc/blob/main/CMakeLists.txt#L174

Can anyone help me fix?

Thanks.

[kleisauke]

This ChangeLog note might be relevant here:

emscripten/ChangeLog.md

Lines 39 to 44 in fdb190d

	- The standard memory views (HEAP8, HEAP32, etc) are no longer exported by
	default. This matches the existing behaviour of `-sSTRICT` and
	`-sMINIMAL_RUNTIME`. If you need to access those from outside the module code
	you can export them by adding them to `-sEXPORTED_RUNTIME_METHODS`. For
	example, `-sEXPORTED_RUNTIME_METHODS=HEAP8,HEAPU32` (if you need `HEAP8` and
	`HEAPU32`). (#24079)

i.e., you also need to link with -sEXPORTED_RUNTIME_METHODS=HEAPU8 if you want to access the HEAPU8 memory view outside the module code.

[sbc100]

Indeed, and if you are building with assertions you should also see and assertion telling you this.

[paulocoutinhox]

Thanks.

1 - What us the correct way?

-sEXPORTED_RUNTIME_METHODS=HEAPU8

or

-sEXPORTED_RUNTIME_METHODS=["HEAPU8"]

2 - With space after -s or no?

[kripken]

Both of those forms work. Also, it works with or without a space after the -s. (We support multiple forms to make it easy to use in different shells, which have difference escaping rules.)

[sbc100]

Th recommended form is the simplest one: -sEXPORTED_RUNTIME_METHODS=HEAPU8

[paulocoutinhox]

Thanks.