Passing a filename containing hyphens to the `wasmer create-exe` command will report `cannot get prefix for atom` error.

[tt4g]

Describe the bug

Versions:

$ wasmer -vV
wasmer 3.2.1 (74fe894 2023-04-21)
binary: wasmer-cli
commit-hash: 74fe894c075351cc40ca5e408bd9a94298a1e459
commit-date: 2023-04-21
host: x86_64-unknown-linux-gnu
compiler: singlepass,cranelift,llvm

$ rustc -vV
rustc 1.69.0 (84c898d65 2023-04-16)
binary: rustc
commit-hash: 84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc
commit-date: 2023-04-16
host: x86_64-unknown-linux-gnu
release: 1.69.0
LLVM version: 15.0.7

I am trying to build .wasm with a very simple Rust project hello-world and generate an executable with wasmer create-exe. However, the wasmer create-exe command always fails.

src/main.rs

fn main() {
    println!("Hello, Wasm!");
}

$ cargo build --target wasm32-wasi
$ wasmer target/wasm32-wasi/debug/hello-wasm.wasm
Hello, Wasm!

$ wasmer create-exe -o ./hello-wasm target/wasm32-wasi/debug/hello-wasm.wasm
Compiler: cranelift
Target: x86_64-unknown-linux-gnu
Using path `/.wasmer/cache/wasmer-linux-amd64/lib/libwasmer-headless.a` as libwasmer path.
error: cannot get prefix for atom hello-world

I found the corresponding Rust code from the error message.

https://github.com/wasmerio/wasmer/blob/74fe894c075351cc40ca5e408bd9a94298a1e459/lib/cli/src/commands/create_exe.rs#L960-L964

I noticed a difference in the way the atom_name is generated.

Statement let atom_name = &atom.atom; was generated by prepare_directory_from_single_wasm_file(). The app_name variable is expected to be assigned hello-world (since the filename is taken from hello-world.wasm).

https://github.com/wasmerio/wasmer/blob/74fe894c075351cc40ca5e408bd9a94298a1e459/lib/cli/src/commands/create_exe.rs#L865-L907

On the other hand, prefixes variables are generated by PrefixMapCompilation::from_input(), which formats the name corresponding to atom_name with normalize_atom_name().

https://github.com/wasmerio/wasmer/blob/74fe894c075351cc40ca5e408bd9a94298a1e459/lib/cli/src/commands/create_exe.rs#L496-L517

normalize_atom_name() function is a simple function that converts - to _. So I renamed the file and the command succeeded.

$ mv target/wasm32-wasi/debug/hello-world.wasm target/wasm32-wasi/debug/hello_world.wasm
$ wasmer create-exe target/wasm32-wasi/debug/hello_world.wasm -o ./hello_world
Compiler: cranelift
Target: x86_64-unknown-linux-gnu
Using path `/.wasmer/cache/wasmer-linux-amd64/lib/libwasmer-headless.a` as libwasmer path.
✔ Native executable compiled successfully to `./hello_world`.
$ ./hello_world 
Hello, world!

Steps to reproduce

Expected behavior

Actual behavior

Additional context

I am not familiar with WebAssembly, so I don't know if there is a "no hyphen in filenames" rule. Is this my mistake? Or is it a bug in wasmer create-exe?

[ptitSeb]

It's a bug on create-exe. Thank you for openning the ticket. Not sure when we will fix this, in the mean time, we should add a document entry to warn about this bug.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Ev1lT3rm1nal]

Any update?