Files
wasmtime/crates/environ/src/tunables.rs
Peter Huene 29d366db7b Add a compile command to Wasmtime.
This commit adds a `compile` command to the Wasmtime CLI.

The command can be used to Ahead-Of-Time (AOT) compile WebAssembly modules.

With the `all-arch` feature enabled, AOT compilation can be performed for
non-native architectures (i.e. cross-compilation).

The `Module::compile` method has been added to perform AOT compilation.

A few of the CLI flags relating to "on by default" Wasm features have been
changed to be "--disable-XYZ" flags.

A simple example of using the `wasmtime compile` command:

```text
$ wasmtime compile input.wasm
$ wasmtime input.cwasm
```
2021-04-01 19:38:18 -07:00

74 lines
2.9 KiB
Rust

use serde::{Deserialize, Serialize};
/// Tunable parameters for WebAssembly compilation.
#[derive(Clone, Hash, Serialize, Deserialize)]
pub struct Tunables {
/// For static heaps, the size in wasm pages of the heap protected by bounds checking.
pub static_memory_bound: u32,
/// The size in bytes of the offset guard for static heaps.
pub static_memory_offset_guard_size: u64,
/// The size in bytes of the offset guard for dynamic heaps.
pub dynamic_memory_offset_guard_size: u64,
/// Whether or not to generate native DWARF debug information.
pub generate_native_debuginfo: bool,
/// Whether or not to retain DWARF sections in compiled modules.
pub parse_wasm_debuginfo: bool,
/// Whether or not to enable the ability to interrupt wasm code dynamically.
///
/// More info can be found about the implementation in
/// crates/environ/src/cranelift.rs. Note that you can't interrupt host
/// calls and interrupts are implemented through the `VMInterrupts`
/// structure, or `InterruptHandle` in the `wasmtime` crate.
pub interruptable: bool,
/// Whether or not fuel is enabled for generated code, meaning that fuel
/// will be consumed every time a wasm instruction is executed.
pub consume_fuel: bool,
/// Whether or not to treat the static memory bound as the maximum for unbounded heaps.
pub static_memory_bound_is_maximum: bool,
}
impl Default for Tunables {
fn default() -> Self {
Self {
#[cfg(target_pointer_width = "32")]
/// Size in wasm pages of the bound for static memories.
static_memory_bound: 0x4000,
#[cfg(target_pointer_width = "64")]
/// Size in wasm pages of the bound for static memories.
///
/// When we allocate 4 GiB of address space, we can avoid the
/// need for explicit bounds checks.
static_memory_bound: 0x1_0000,
#[cfg(target_pointer_width = "32")]
/// Size in bytes of the offset guard for static memories.
static_memory_offset_guard_size: 0x1_0000,
#[cfg(target_pointer_width = "64")]
/// Size in bytes of the offset guard for static memories.
///
/// Allocating 2 GiB of address space lets us translate wasm
/// offsets into x86 offsets as aggressively as we can.
static_memory_offset_guard_size: 0x8000_0000,
/// Size in bytes of the offset guard for dynamic memories.
///
/// Allocate a small guard to optimize common cases but without
/// wasting too much memory.
dynamic_memory_offset_guard_size: 0x1_0000,
generate_native_debuginfo: false,
parse_wasm_debuginfo: true,
interruptable: false,
consume_fuel: false,
static_memory_bound_is_maximum: false,
}
}
}