Files
wasmtime/crates/c-api/src/ext.rs
Alex Crichton 6ef09359b0 Refactor and fill out wasmtime's C API (#1415)
* Refactor and improve safety of C API

This commit is intended to be a relatively large refactoring of the C
API which is targeted at improving the safety of our C API definitions.
Not all of the APIs have been updated yet but this is intended to be the
start.

The goal here is to make as many functions safe as we can, expressing
inputs/outputs as native Rust types rather than raw pointers wherever
possible. For example instead of `*const wasm_foo_t` we'd take
`&wasm_foo_t`. Instead of returning `*mut wasm_foo_t` we'd return
`Box<wasm_foo_t>`. No ABI/API changes are intended from this commit,
it's supposed to only change how we define all these functions
internally.

This commit also additionally implements a few more API bindings for
exposed vector types by unifying everything into one macro.

Finally, this commit moves many internal caches in the C API to the
`OnceCell` type which provides a safe interface for one-time
initialization.

* Split apart monolithic C API `lib.rs`

This commit splits the monolithic `src/lib.rs` in the C API crate into
lots of smaller files. The goal here is to make this a bit more readable
and digestable. Each module now contains only API bindings for a
particular type, roughly organized around the grouping in the wasm.h
header file already.

A few more extensions were added, such as filling out `*_as_*`
conversions with both const and non-const versions. Additionally many
APIs were made safer in the same style as the previous commit, generally
preferring Rust types rather than raw pointer types.

Overall no functional change is intended here, it should be mostly just
code movement and minor refactorings!

* Make a few wasi C bindings safer

Use safe Rust types where we can and touch up a few APIs here and there.

* Implement `wasm_*type_as_externtype*` APIs

This commit restructures `wasm_externtype_t` to be similar to
`wasm_extern_t` so type conversion between the `*_extern_*` variants to
the concrete variants are all simple casts. (checked in the case of
general to concrete, of course).

* Consistently imlpement host info functions in the API

This commit adds a small macro crate which is then used to consistently
define the various host-info-related functions in the C API. The goal
here is to try to mirror what the `wasm.h` header provides to provide a
full implementation of the header.
2020-03-27 09:50:32 -05:00

287 lines
8.0 KiB
Rust

//! This file defines the extern "C" API extension, which are specific
//! to the wasmtime implementation.
use crate::*;
use std::str;
use wasmtime::{Extern, Linker, OptLevel, ProfilingStrategy, Strategy};
#[repr(u8)]
#[derive(Clone)]
pub enum wasmtime_strategy_t {
WASMTIME_STRATEGY_AUTO,
WASMTIME_STRATEGY_CRANELIFT,
WASMTIME_STRATEGY_LIGHTBEAM,
}
#[repr(u8)]
#[derive(Clone)]
pub enum wasmtime_opt_level_t {
WASMTIME_OPT_LEVEL_NONE,
WASMTIME_OPT_LEVEL_SPEED,
WASMTIME_OPT_LEVEL_SPEED_AND_SIZE,
}
#[repr(u8)]
#[derive(Clone)]
pub enum wasmtime_profiling_strategy_t {
WASMTIME_PROFILING_STRATEGY_NONE,
WASMTIME_PROFILING_STRATEGY_JITDUMP,
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_debug_info_set(c: *mut wasm_config_t, enable: bool) {
(*c).config.debug_info(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_wasm_threads_set(c: *mut wasm_config_t, enable: bool) {
(*c).config.wasm_threads(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_wasm_reference_types_set(
c: *mut wasm_config_t,
enable: bool,
) {
(*c).config.wasm_reference_types(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_wasm_simd_set(c: *mut wasm_config_t, enable: bool) {
(*c).config.wasm_simd(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_wasm_bulk_memory_set(c: *mut wasm_config_t, enable: bool) {
(*c).config.wasm_bulk_memory(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_wasm_multi_value_set(c: *mut wasm_config_t, enable: bool) {
(*c).config.wasm_multi_value(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_strategy_set(
c: *mut wasm_config_t,
strategy: wasmtime_strategy_t,
) {
use wasmtime_strategy_t::*;
drop((*c).config.strategy(match strategy {
WASMTIME_STRATEGY_AUTO => Strategy::Auto,
WASMTIME_STRATEGY_CRANELIFT => Strategy::Cranelift,
WASMTIME_STRATEGY_LIGHTBEAM => Strategy::Lightbeam,
}));
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_cranelift_debug_verifier_set(
c: *mut wasm_config_t,
enable: bool,
) {
(*c).config.cranelift_debug_verifier(enable);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_cranelift_opt_level_set(
c: *mut wasm_config_t,
opt_level: wasmtime_opt_level_t,
) {
use wasmtime_opt_level_t::*;
(*c).config.cranelift_opt_level(match opt_level {
WASMTIME_OPT_LEVEL_NONE => OptLevel::None,
WASMTIME_OPT_LEVEL_SPEED => OptLevel::Speed,
WASMTIME_OPT_LEVEL_SPEED_AND_SIZE => OptLevel::SpeedAndSize,
});
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_config_profiler_set(
c: *mut wasm_config_t,
strategy: wasmtime_profiling_strategy_t,
) {
use wasmtime_profiling_strategy_t::*;
drop((*c).config.profiler(match strategy {
WASMTIME_PROFILING_STRATEGY_NONE => ProfilingStrategy::None,
WASMTIME_PROFILING_STRATEGY_JITDUMP => ProfilingStrategy::JitDump,
}));
}
#[no_mangle]
pub extern "C" fn wasmtime_wat2wasm(
wat: &wasm_byte_vec_t,
ret: &mut wasm_byte_vec_t,
error: Option<&mut wasm_byte_vec_t>,
) -> bool {
let wat = match str::from_utf8(wat.as_slice()) {
Ok(s) => s,
Err(_) => {
if let Some(error) = error {
error.set_buffer(b"input was not valid utf-8".to_vec());
}
return false;
}
};
match wat::parse_str(wat) {
Ok(bytes) => {
ret.set_buffer(bytes.into());
true
}
Err(e) => {
if let Some(error) = error {
error.set_buffer(e.to_string().into_bytes());
}
false
}
}
}
#[repr(C)]
pub struct wasmtime_linker_t {
linker: Linker,
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_new(store: *mut wasm_store_t) -> *mut wasmtime_linker_t {
Box::into_raw(Box::new(wasmtime_linker_t {
linker: Linker::new(&(*store).store.borrow()),
}))
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_allow_shadowing(
linker: *mut wasmtime_linker_t,
allow_shadowing: bool,
) {
(*linker).linker.allow_shadowing(allow_shadowing);
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_delete(linker: *mut wasmtime_linker_t) {
drop(Box::from_raw(linker));
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_define(
linker: *mut wasmtime_linker_t,
module: *const wasm_name_t,
name: *const wasm_name_t,
item: *const wasm_extern_t,
) -> bool {
let linker = &mut (*linker).linker;
let module = match str::from_utf8((*module).as_slice()) {
Ok(s) => s,
Err(_) => return false,
};
let name = match str::from_utf8((*name).as_slice()) {
Ok(s) => s,
Err(_) => return false,
};
let item = match &(*item).which {
ExternHost::Func(e) => Extern::Func(e.borrow().clone()),
ExternHost::Table(e) => Extern::Table(e.borrow().clone()),
ExternHost::Global(e) => Extern::Global(e.borrow().clone()),
ExternHost::Memory(e) => Extern::Memory(e.borrow().clone()),
};
linker.define(module, name, item).is_ok()
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_define_wasi(
linker: *mut wasmtime_linker_t,
instance: *const wasi_instance_t,
) -> bool {
let linker = &mut (*linker).linker;
(*instance).add_to_linker(linker).is_ok()
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_define_instance(
linker: *mut wasmtime_linker_t,
name: *const wasm_name_t,
instance: *const wasm_instance_t,
) -> bool {
let linker = &mut (*linker).linker;
let name = match str::from_utf8((*name).as_slice()) {
Ok(s) => s,
Err(_) => return false,
};
linker
.instance(name, &(*instance).instance.borrow())
.is_ok()
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_linker_instantiate(
linker: *const wasmtime_linker_t,
module: *const wasm_module_t,
trap: *mut *mut wasm_trap_t,
) -> *mut wasm_instance_t {
let linker = &(*linker).linker;
handle_instantiate(linker.instantiate(&(*module).module.borrow()), trap)
}
pub type wasmtime_func_callback_t = unsafe extern "C" fn(
caller: *const wasmtime_caller_t,
args: *const wasm_val_t,
results: *mut wasm_val_t,
) -> *mut wasm_trap_t;
pub type wasmtime_func_callback_with_env_t = unsafe extern "C" fn(
caller: *const wasmtime_caller_t,
env: *mut std::ffi::c_void,
args: *const wasm_val_t,
results: *mut wasm_val_t,
) -> *mut wasm_trap_t;
#[repr(C)]
pub struct wasmtime_caller_t<'a> {
pub inner: wasmtime::Caller<'a>,
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_func_new(
store: *mut wasm_store_t,
ty: *const wasm_functype_t,
callback: wasmtime_func_callback_t,
) -> *mut wasm_func_t {
crate::create_function(store, ty, crate::Callback::Wasmtime(callback))
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_func_new_with_env(
store: *mut wasm_store_t,
ty: *const wasm_functype_t,
callback: wasmtime_func_callback_with_env_t,
env: *mut std::ffi::c_void,
finalizer: Option<unsafe extern "C" fn(arg1: *mut std::ffi::c_void)>,
) -> *mut wasm_func_t {
crate::create_function_with_env(
store,
ty,
crate::CallbackWithEnv::Wasmtime(callback),
env,
finalizer,
)
}
#[no_mangle]
pub unsafe extern "C" fn wasmtime_caller_export_get(
caller: *const wasmtime_caller_t,
name: *const wasm_name_t,
) -> *mut wasm_extern_t {
let name = match str::from_utf8((*name).as_slice()) {
Ok(s) => s,
Err(_) => return std::ptr::null_mut(),
};
match (*caller).inner.get_export(name).map(|e| match e {
Extern::Func(f) => ExternHost::Func(HostRef::new(f.clone())),
Extern::Global(g) => ExternHost::Global(HostRef::new(g.clone())),
Extern::Memory(m) => ExternHost::Memory(HostRef::new(m.clone())),
Extern::Table(t) => ExternHost::Table(HostRef::new(t.clone())),
}) {
Some(export) => Box::into_raw(Box::new(wasm_extern_t { which: export })),
None => std::ptr::null_mut(),
}
}