This commit is contained in:
elfein 2021-11-12 02:50:17 -08:00
commit 5b01f3c2b1
3 changed files with 87 additions and 86 deletions

View file

@ -1,7 +1,7 @@
use wabt; use wabt;
use wasmi::{ use wasmi::{
Error, Externals, FuncInstance, FuncRef, ImportsBuilder, ModuleImportResolver, ModuleInstance, Error, Externals, FuncInstance, FuncRef, ImportsBuilder, ModuleImportResolver, ModuleInstance,
RuntimeArgs, RuntimeValue, Signature, Trap, ValueType, RuntimeArgs, RuntimeValue, Signature, Trap, ValueType,
}; };
mod wasm_sys; mod wasm_sys;
@ -11,102 +11,103 @@ pub const KILL: usize = 0;
struct HostFunctions; struct HostFunctions;
impl HostFunctions { impl HostFunctions {
fn check_signature(&self, index: usize, signature: &Signature) -> bool { fn check_signature(&self, index: usize, signature: &Signature) -> bool {
let (params, ret_ty): (&[ValueType], Option<ValueType>) = match index.into() { let (params, ret_ty): (&[ValueType], Option<ValueType>) = match index.into() {
SysCall::KILL => (&[ValueType::I32, ValueType::I32], Some(ValueType::I32)), SysCall::KILL => (&[ValueType::I32, ValueType::I32], Some(ValueType::I32)),
_ => return false, SysCall::EMPTY => (&[], None),
}; _ => return false,
signature.params() == params && signature.return_type() == ret_ty };
} signature.params() == params && signature.return_type() == ret_ty
}
} }
impl Externals for HostFunctions { impl Externals for HostFunctions {
fn invoke_index( fn invoke_index(
&mut self, &mut self,
index: usize, index: usize,
args: RuntimeArgs, args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Trap> { ) -> Result<Option<RuntimeValue>, Trap> {
match index.into() { match index.into() {
SysCall::KILL => { SysCall::KILL => {
let a: u32 = args.nth_checked(0)?; let a: u32 = args.nth_checked(0)?;
let b: u32 = args.nth_checked(1)?; let b: u32 = args.nth_checked(1)?;
let result = a + b; let result = a + b;
Ok(Some(RuntimeValue::I32(result as i32))) Ok(Some(RuntimeValue::I32(result as i32)))
} }
SysCall::CONSOLE_RESET => {} SysCall::EMPTY => Ok(None),
SysCall::CONSOLE_IN => {} // SysCall::CONSOLE_RESET => {}
SysCall::CONSOLE_OUT => {} // SysCall::CONSOLE_IN => {}
SysCall::CONSOLE_GET_TITLE => {} // SysCall::CONSOLE_OUT => {}
SysCall::CONSOLE_SET_TITLE => {} // SysCall::CONSOLE_GET_TITLE => {}
// SysCall::CONSOLE_SET_TITLE => {}
_ => panic!("Unimplemented function at {}", index), _ => panic!("Unimplemented function at {}", index),
} }
} }
} }
impl ModuleImportResolver for HostFunctions { impl ModuleImportResolver for HostFunctions {
fn resolve_func(&self, field_name: &str, signature: &Signature) -> Result<FuncRef, Error> { fn resolve_func(&self, field_name: &str, signature: &Signature) -> Result<FuncRef, Error> {
let index = match field_name { let index = match field_name {
"add" => SysCall::KILL as usize, "add" => SysCall::KILL as usize,
_ => { "empty" => SysCall::EMPTY as usize,
_ => {
return Err(Error::Instantiation(format!(
"Export {} not found",
field_name
)))
}
};
if !self.check_signature(index, signature) {
return Err(Error::Instantiation(format!( return Err(Error::Instantiation(format!(
"Export {} not found", "Export {} has a bad signature",
field_name field_name
))) )));
} }
};
if !self.check_signature(index, signature) { Ok(FuncInstance::alloc_host(
return Err(Error::Instantiation(format!( Signature::new(&[ValueType::I32, ValueType::I32][..], Some(ValueType::I32)),
"Export {} has a bad signature", index,
field_name ))
))); }
}
Ok(FuncInstance::alloc_host(
Signature::new(&[ValueType::I32, ValueType::I32][..], Some(ValueType::I32)),
index,
))
}
} }
fn main() { fn main() {
// Parse WAT (WebAssembly Text format) into wasm bytecode. // Parse WAT (WebAssembly Text format) into wasm bytecode.
let wasm_binary = wabt::wat2wasm(include_str!("../wasm/test.wat")); let wasm_binary = wabt::wat2wasm(include_str!("../wasm/test.wat"));
let wasm_binary = match wasm_binary { let wasm_binary = match wasm_binary {
Ok(abc) => abc, Ok(abc) => abc,
Err(abc) => { Err(abc) => {
println!("{}", abc); println!("{}", abc);
return; return;
} }
}; };
// .expect("failed to parse wat"); // .expect("failed to parse wat");
// Load wasm binary and prepare it for instantiation. // Load wasm binary and prepare it for instantiation.
let module = wasmi::Module::from_buffer(&wasm_binary).expect("failed to load wasm"); let module = wasmi::Module::from_buffer(&wasm_binary).expect("failed to load wasm");
let imports = ImportsBuilder::new().with_resolver("host", &HostFunctions); let imports = ImportsBuilder::new().with_resolver("host", &HostFunctions);
// Instantiate a module with empty imports and // Instantiate a module with empty imports and
// assert that there is no `start` function. // assert that there is no `start` function.
let instance = ModuleInstance::new(&module, &imports) let instance = ModuleInstance::new(&module, &imports)
.expect("failed to instantiate wasm module") .expect("failed to instantiate wasm module")
.assert_no_start(); .assert_no_start();
// Finally, invoke the exported function "test" with no parameters // Finally, invoke the exported function "test" with no parameters
// and empty external function executor. // and empty external function executor.
let result: i32 = instance let result: i32 = instance
.invoke_export("main", &[], &mut HostFunctions) .invoke_export("main", &[], &mut HostFunctions)
// .with_resolver(&mut HostFunctions) // .with_resolver(&mut HostFunctions)
.expect("failed to execute export") .expect("failed to execute export")
.unwrap() .unwrap()
.try_into() .try_into()
.unwrap(); .unwrap();
println!( println!(
"{:?}", "{:?}",
result // .unwrap() result // .unwrap()
); );
} }

View file

@ -1,4 +1,5 @@
macro_rules! syscall_enum { macro_rules! syscall_enum {
() => {};
(@get_last $Variant:ident) => { (@get_last $Variant:ident) => {
Self::$Variant Self::$Variant
}; };
@ -71,9 +72,6 @@ syscall_enum! {
SOCKET_SEND=42, SOCKET_SEND=42,
SOCKET_RECEIVE=43, SOCKET_RECEIVE=43,
// Security Syscalls // Security Syscalls
ENCRYPT=50, ENCRYPT=50,
EMPTY=0xFFFF, EMPTY=0xFFFF,

View file

@ -1,6 +1,8 @@
(module (module
(import "host" "add" (func $add (param i32 i32)(result i32))) (import "host" "add" (func $add (param i32 i32)(result i32)))
(; (import "host" "empty" (func $empty)) ;)
(func (export "main") (result i32) (func (export "main") (result i32)
(; (call $empty) ;)
(call $add (i32.const 123) (i32.const 456)) (call $add (i32.const 123) (i32.const 456))
) )
) )