420dcd76fd
* Don't require `Store` in `Instance` constructor This can be inferred from the `Module` argument. Additionally add a `store` accessor to an `Instance` in case it's needed to instantiate another `Module`. cc #708 * Update more constructors * Fix a doctest * Don't ignore store in `wasm_instance_new` * Run rustfmt
96 lines
3.0 KiB
Rust
96 lines
3.0 KiB
Rust
use anyhow::{bail, Context};
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use std::fs::File;
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use std::path::Path;
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use wasmtime::{Instance, Module, Store};
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pub fn instantiate(data: &[u8], bin_name: &str, workspace: Option<&Path>) -> anyhow::Result<()> {
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let store = Store::default();
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let global_exports = store.global_exports().clone();
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let get_preopens = |workspace: Option<&Path>| -> anyhow::Result<Vec<_>> {
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if let Some(workspace) = workspace {
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let preopen_dir = wasi_common::preopen_dir(workspace)
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.context(format!("error while preopening {:?}", workspace))?;
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Ok(vec![(".".to_owned(), preopen_dir)])
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} else {
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Ok(vec![])
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}
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};
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// Create our wasi context with pretty standard arguments/inheritance/etc.
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// Additionally register andy preopened directories if we have them.
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let mut builder = wasi_common::WasiCtxBuilder::new()
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.arg(bin_name)
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.arg(".")
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.inherit_stdio();
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for (dir, file) in get_preopens(workspace)? {
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builder = builder.preopened_dir(file, dir);
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}
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// The nonstandard thing we do with `WasiCtxBuilder` is to ensure that
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// `stdin` is always an unreadable pipe. This is expected in the test suite
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// where `stdin` is never ready to be read. In some CI systems, however,
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// stdin is closed which causes tests to fail.
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let (reader, _writer) = os_pipe::pipe()?;
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builder = builder.stdin(reader_to_file(reader));
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let snapshot1 = Instance::from_handle(
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&store,
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wasmtime_wasi::instantiate_wasi_with_context(
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global_exports.clone(),
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builder.build().context("failed to build wasi context")?,
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)
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.context("failed to instantiate wasi")?,
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);
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let module = Module::new(&store, &data).context("failed to create wasm module")?;
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let imports = module
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.imports()
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.iter()
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.map(|i| {
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let field_name = i.name();
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if let Some(export) = snapshot1.find_export_by_name(field_name) {
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Ok(export.clone())
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} else {
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bail!(
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"import {} was not found in module {}",
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field_name,
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i.module(),
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)
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}
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})
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.collect::<Result<Vec<_>, _>>()?;
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let instance = Instance::new(&module, &imports).context(format!(
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"error while instantiating Wasm module '{}'",
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bin_name,
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))?;
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let export = instance
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.find_export_by_name("_start")
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.context("expected a _start export")?
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.clone();
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if let Err(trap) = export
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.func()
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.context("expected export to be a func")?
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.call(&[])
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{
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bail!("trapped: {:?}", trap);
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}
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Ok(())
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}
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#[cfg(unix)]
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fn reader_to_file(reader: os_pipe::PipeReader) -> File {
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use std::os::unix::prelude::*;
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unsafe { File::from_raw_fd(reader.into_raw_fd()) }
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}
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#[cfg(windows)]
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fn reader_to_file(reader: os_pipe::PipeReader) -> File {
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use std::os::windows::prelude::*;
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unsafe { File::from_raw_handle(reader.into_raw_handle()) }
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}
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