The name section is removed by `binaryen.readBinary`

[lastmjs]

Hello,

It looks like binaryen.readBinary is removing the name custom section. No other custom sections in my test case are removed.

I start with a raw Wasm binary file that does have a name section, here is the result of wasm-objdump -h:

wasm-objdump -h wasm_before_raw.wasm 

wasm_before_raw.wasm:	file format wasm 0x1
module name: <stable_canister_template.wasm>

Sections:

     Type start=0x0000000b end=0x000004c7 (size=0x000004bc) count: 147
   Import start=0x000004ca end=0x00000886 (size=0x000003bc) count: 41
 Function start=0x00000889 end=0x000015db (size=0x00000d52) count: 3327
    Table start=0x000015dd end=0x000015e4 (size=0x00000007) count: 1
   Memory start=0x000015e6 end=0x000015e9 (size=0x00000003) count: 1
   Global start=0x000015eb end=0x000015f4 (size=0x00000009) count: 1
   Export start=0x000015f7 end=0x00001cc3 (size=0x000006cc) count: 63
     Elem start=0x00001cc6 end=0x000024fd (size=0x00000837) count: 1
     Code start=0x00002502 end=0x00220dbc (size=0x0021e8ba) count: 3327
     Data start=0x00220dc0 end=0x00279180 (size=0x000583c0) count: 2
   Custom start=0x00279184 end=0x002ac5d1 (size=0x0003344d) "name"
   Custom start=0x002ac5d4 end=0x002ac69a (size=0x000000c6) "producers"
   Custom start=0x002ac69c end=0x002ac6f2 (size=0x00000056) "target_features"

And then I run this TypeScript code:

export async function getModule(
    wasmBinaryPath: string
): Promise<binaryen.Module> {
    const originalWasm = await readFile(wasmBinaryPath);
    const module = binaryen.readBinary(originalWasm);

    return module;
}

And I write the binary to a file just after calling getModule:

    const module = await getModule(canisterTemplatePath);

    await writeFile('wasm_before.wasm', module.emitBinary());

When I run wasm-objdump -h on wasm_before.wasm I get this:

wasm-objdump -h wasm_before.wasm 

wasm_before.wasm:	file format wasm 0x1

Sections:

     Type start=0x0000000b end=0x000004c7 (size=0x000004bc) count: 147
   Import start=0x000004ca end=0x00000881 (size=0x000003b7) count: 41
 Function start=0x00000884 end=0x00001598 (size=0x00000d14) count: 3327
    Table start=0x0000159a end=0x000015a1 (size=0x00000007) count: 1
   Memory start=0x000015a3 end=0x000015a6 (size=0x00000003) count: 1
   Global start=0x000015a8 end=0x000015b1 (size=0x00000009) count: 1
   Export start=0x000015b4 end=0x00001c80 (size=0x000006cc) count: 63
     Elem start=0x00001c83 end=0x000024ba (size=0x00000837) count: 1
DataCount start=0x000024bc end=0x000024bd (size=0x00000001) count: 2
     Code start=0x000024c2 end=0x00221324 (size=0x0021ee62) count: 3327
     Data start=0x00221328 end=0x002796e8 (size=0x000583c0) count: 2
   Custom start=0x002796eb end=0x002797b1 (size=0x000000c6) "producers"
   Custom start=0x002797b3 end=0x0027981a (size=0x00000067) "target_features"

I'm currently on version 116.0.0, but even updating temporarily to 123.0.0 has not solved the problem.

[lastmjs]

It looks like there are some other changes as well...the module name, the DataCount, and the start and end locations and sizes quickly start to have discrepancies.

[lastmjs]

I figured this out, if you set binaryen.setDebugInfo(true); before binaryen.readBinary then the name section is preserved.