Files
wasmtime/crates/test-programs/tests/wasm_tests/runtime.rs
Dan Gohman 9a88d3d894 Replace the global-exports mechanism with a caller-vmctx mechanism. (#789)
* Replace the global-exports mechanism with a caller-vmctx mechanism.

This eliminates the global exports mechanism, and instead adds a
caller-vmctx argument to wasm functions so that WASI can obtain the
memory and other things from the caller rather than looking them up in a
global registry.

This replaces #390.

* Fixup some merge conflicts

* Rustfmt

* Ensure VMContext is aligned to 16 bytes

With the removal of `global_exports` it "just so happens" that this
isn't happening naturally any more.

* Fixup some bugs with double vmctx in wasmtime crate

* Trampoline stub needed adjusting
* Use pointer type instead of always using I64 for caller vmctx
* Don't store `ir::Signature` in `Func` since we don't know the pointer
  size at creation time.
* Skip the first 2 arguments in IR signatures since that's the two vmctx
  parameters.

* Update cranelift to 0.56.0

* Handle more merge conflicts

* Rustfmt

Co-authored-by: Alex Crichton <alex@alexcrichton.com>
2020-01-21 14:50:59 -08:00

91 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 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(
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()) }
}