wasmer/lib/runtime/src/lib.rs

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//! Wasmer-runtime is a library that makes embedding WebAssembly
//! in your application easy, efficient, and safe.
//!
//! # How to use Wasmer-Runtime
//!
//! The easiest way is to use the [`instantiate`] function to create an [`Instance`].
//! Then you can use [`call`] or [`func`] and then [`call`][func.call] to call an exported function safely.
//!
//! [`instantiate`]: fn.instantiate.html
//! [`Instance`]: struct.Instance.html
//! [`call`]: struct.Instance.html#method.call
//! [`func`]: struct.Instance.html#method.func
//! [func.call]: struct.Function.html#method.call
//!
//! ## Here's an example:
//!
//! Given this WebAssembly:
//!
//! ```wat
//! (module
//! (type $t0 (func (param i32) (result i32)))
//! (func $add_one (export "add_one") (type $t0) (param $p0 i32) (result i32)
//! get_local $p0
//! i32.const 1
//! i32.add))
//! ```
//!
//! compiled into wasm bytecode, we can call the exported "add_one" function:
//!
//! ```
//! static WASM: &'static [u8] = &[
//! // The module above compiled to bytecode goes here.
//! // ...
//! # 0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x06, 0x01, 0x60,
//! # 0x01, 0x7f, 0x01, 0x7f, 0x03, 0x02, 0x01, 0x00, 0x07, 0x0b, 0x01, 0x07,
//! # 0x61, 0x64, 0x64, 0x5f, 0x6f, 0x6e, 0x65, 0x00, 0x00, 0x0a, 0x09, 0x01,
//! # 0x07, 0x00, 0x20, 0x00, 0x41, 0x01, 0x6a, 0x0b, 0x00, 0x1a, 0x04, 0x6e,
//! # 0x61, 0x6d, 0x65, 0x01, 0x0a, 0x01, 0x00, 0x07, 0x61, 0x64, 0x64, 0x5f,
//! # 0x6f, 0x6e, 0x65, 0x02, 0x07, 0x01, 0x00, 0x01, 0x00, 0x02, 0x70, 0x30,
//! ];
//!
//! use wasmer_runtime::{
//! instantiate,
//! Value,
//! imports,
//! error,
//! };
//!
//! fn main() -> error::Result<()> {
//! // We're not importing anything, so make an empty import object.
//! let import_object = imports! {};
//!
//! let mut instance = instantiate(WASM, import_object)?;
//!
//! let values = instance
//! .func("add_one")?
//! .call(&[Value::I32(42)])?;
//!
//! assert_eq!(values[0], Value::I32(43));
//!
//! Ok(())
//! }
//! ```
//!
//! # Additional Notes:
//!
//! The `wasmer-runtime` is build to support compiler multiple backends.
//! Currently, we support the [Cranelift] compiler with the [`wasmer-clif-backend`] crate.
//!
//! You can specify the compiler you wish to use with the [`compile_with`] function.
//!
//! [Cranelift]: https://github.com/CraneStation/cranelift
//! [`wasmer-clif-backend`]: https://crates.io/crates/wasmer-clif-backend
//! [`compile_with`]: fn.compile_with.html
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pub use wasmer_runtime_core::global::Global;
pub use wasmer_runtime_core::import::ImportObject;
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pub use wasmer_runtime_core::instance::{Function, Instance};
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pub use wasmer_runtime_core::memory::Memory;
pub use wasmer_runtime_core::module::Module;
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pub use wasmer_runtime_core::table::Table;
pub use wasmer_runtime_core::types::Value;
pub use wasmer_runtime_core::vm::Ctx;
pub use wasmer_runtime_core::{compile_with, validate};
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pub use wasmer_runtime_core::error;
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pub use wasmer_runtime_core::{func, imports};
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pub mod wasm {
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pub use wasmer_runtime_core::global::Global;
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pub use wasmer_runtime_core::instance::Function;
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pub use wasmer_runtime_core::memory::Memory;
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pub use wasmer_runtime_core::table::Table;
pub use wasmer_runtime_core::types::{FuncSig, MemoryDesc, TableDesc, Type, Value};
}
/// Compile WebAssembly binary code into a [`Module`].
/// This function is useful if it is necessary to
/// compile a module before it can be instantiated
/// (otherwise, the [`instantiate`] function should be used).
///
/// [`Module`]: struct.Module.html
/// [`instantiate`]: fn.instantiate.html
///
/// # Params:
/// * `wasm`: A `&[u8]` containing the
/// binary code of the wasm module you want to compile.
/// # Errors:
/// If the operation fails, the function returns `Err(error::CompileError::...)`.
#[cfg(feature = "wasmer-clif-backend")]
pub fn compile(wasm: &[u8]) -> error::CompileResult<Module> {
use wasmer_clif_backend::CraneliftCompiler;
wasmer_runtime_core::compile_with(&wasm[..], &CraneliftCompiler::new())
}
/// Compile and instantiate WebAssembly code without
/// creating a [`Module`].
///
/// [`Module`]: struct.Module.html
///
/// # Params:
/// * `wasm`: A `&[u8]` containing the
/// binary code of the wasm module you want to compile.
/// * `import_object`: An object containing the values to be imported
/// into the newly-created Instance, such as functions or
/// Memory objects. There must be one matching property
/// for each declared import of the compiled module or else a
/// LinkError is thrown.
/// # Errors:
/// If the operation fails, the function returns a
/// `error::CompileError`, `error::LinkError`, or
/// `error::RuntimeError` (all combined into an `error::Error`),
/// depending on the cause of the failure.
#[cfg(feature = "wasmer-clif-backend")]
pub fn instantiate(wasm: &[u8], import_object: ImportObject) -> error::Result<Instance> {
let module = compile(wasm)?;
module.instantiate(import_object)
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}
/// The current version of this crate
pub const VERSION: &str = env!("CARGO_PKG_VERSION");