<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/80258>80258</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Wasm: Functions forcefully marked export by linker
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          ryandurkoske
      </td>
    </tr>
</table>

<pre>
    If I generate a relocatable wasm object file using wat2wasm, link the object in with the rest of my C program on wasm-ld, then all the functions defined in the object file are forcefully marked as exports.  

I'm excited that _it just works_, except for this particular annoyance. Marking the extern declaration with hidden visibility does not make a difference.

I know its not an issue on wabt's part. Here is the disassembly of the relocatable obj file generated by wat2wasm:

```
(module
  (type (;0;) (func (param i32)))
 (import "env" "memory" (memory (;0;) 2 65536 shared))
  (func $mtx_lock (type 0) (param i32)
    ...instructions...)
  (func $mtx_unlock (type 0) (param i32)
    ...instructions...)
  (@custom "linking" "\02\08\1b\02\00\00\00\08mtx_lock\00\00\01\0amtx_unlock"))
```

Here is my extern declaration of the functions in a header file:
```
__attribute__((visibility("default"))) extern void mtx_lock(mtx_t* mut_ptr);
__attribute__((visibility("default"))) extern void mtx_unlock(mtx_t* mutex_ptr);
```

Clang C Source compiler flags: (clang version 17.0.6)
```
-std=c17 -target wasm32 -flto
-Wall -g -O3 
-nostdlib -fvisibility=hidden
-mbulk-memory -msimd128 -matomics -mmutable-globals 

```
wasm-ld flags: (LLD version 17.0.6)
```
--export-dynamic --unresolved-symbols=report-all --import-memory --error-limit=0 --stack-first --gc-sections 
-O3 --shared-memory --max-memory=4294967296 -zstack-size=65536
```

For further clarity, heres the undesirable result from the disassembly of the wasm linker output:
```
...function definitions...
...more exports...
 (export "mtx_lock" (func $mtx_lock))
 (export "mtx_unlock" (func $mtx_unlock))
... data ...
... @custom data ...
```

This is the reverse behavior of a similar issue with llvm-ar generated archive files.  The linker or the archiver is stripping the visibility off of C declared/defined functions.
</pre>
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