e5afdd2ede
* Document the `wasmtime::Instance` APIs This documents oddities like the import list and export list and how to match them all up. Addtionally this largely just expands all the docs related to `Instance` to get filled out. This also moves the `set_signal_handler` functions into platform-specific modules in order to follow Rust idioms about how to expose platform-specific information. Additionally the methods are marked `unsafe` because I figure anything having to do with signal handling is `unsafe` inherently. I don't actually know what these functions do, so they're currently still undocumented. * Fix build of python bindings * Fix some rebase conflicts
93 lines
2.9 KiB
Rust
93 lines
2.9 KiB
Rust
use anyhow::{bail, Context};
|
|
use std::fs::File;
|
|
use std::path::Path;
|
|
use wasmtime::{Instance, Module, Store};
|
|
|
|
pub fn instantiate(data: &[u8], bin_name: &str, workspace: Option<&Path>) -> anyhow::Result<()> {
|
|
let store = Store::default();
|
|
|
|
let global_exports = store.global_exports().clone();
|
|
let get_preopens = |workspace: Option<&Path>| -> anyhow::Result<Vec<_>> {
|
|
if let Some(workspace) = workspace {
|
|
let preopen_dir = wasi_common::preopen_dir(workspace)
|
|
.context(format!("error while preopening {:?}", workspace))?;
|
|
|
|
Ok(vec![(".".to_owned(), preopen_dir)])
|
|
} else {
|
|
Ok(vec![])
|
|
}
|
|
};
|
|
|
|
// Create our wasi context with pretty standard arguments/inheritance/etc.
|
|
// Additionally register andy preopened directories if we have them.
|
|
let mut builder = wasi_common::WasiCtxBuilder::new()
|
|
.arg(bin_name)
|
|
.arg(".")
|
|
.inherit_stdio();
|
|
for (dir, file) in get_preopens(workspace)? {
|
|
builder = builder.preopened_dir(file, dir);
|
|
}
|
|
|
|
// The nonstandard thing we do with `WasiCtxBuilder` is to ensure that
|
|
// `stdin` is always an unreadable pipe. This is expected in the test suite
|
|
// where `stdin` is never ready to be read. In some CI systems, however,
|
|
// stdin is closed which causes tests to fail.
|
|
let (reader, _writer) = os_pipe::pipe()?;
|
|
builder = builder.stdin(reader_to_file(reader));
|
|
let snapshot1 = Instance::from_handle(
|
|
&store,
|
|
wasmtime_wasi::instantiate_wasi_with_context(
|
|
global_exports.clone(),
|
|
builder.build().context("failed to build wasi context")?,
|
|
)
|
|
.context("failed to instantiate wasi")?,
|
|
);
|
|
|
|
let module = Module::new(&store, &data).context("failed to create wasm module")?;
|
|
let imports = module
|
|
.imports()
|
|
.iter()
|
|
.map(|i| {
|
|
let field_name = i.name();
|
|
if let Some(export) = snapshot1.get_export(field_name) {
|
|
Ok(export.clone())
|
|
} else {
|
|
bail!(
|
|
"import {} was not found in module {}",
|
|
field_name,
|
|
i.module(),
|
|
)
|
|
}
|
|
})
|
|
.collect::<Result<Vec<_>, _>>()?;
|
|
|
|
let instance = Instance::new(&module, &imports).context(format!(
|
|
"error while instantiating Wasm module '{}'",
|
|
bin_name,
|
|
))?;
|
|
|
|
let export = instance
|
|
.get_export("_start")
|
|
.context("expected a _start export")?
|
|
.clone();
|
|
|
|
export
|
|
.func()
|
|
.context("expected export to be a func")?
|
|
.call(&[])?;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
#[cfg(unix)]
|
|
fn reader_to_file(reader: os_pipe::PipeReader) -> File {
|
|
use std::os::unix::prelude::*;
|
|
unsafe { File::from_raw_fd(reader.into_raw_fd()) }
|
|
}
|
|
|
|
#[cfg(windows)]
|
|
fn reader_to_file(reader: os_pipe::PipeReader) -> File {
|
|
use std::os::windows::prelude::*;
|
|
unsafe { File::from_raw_handle(reader.into_raw_handle()) }
|
|
}
|