Merge pull request #6 from pepyakin/args-wrapper

Safe/utility arguments wrapper
This commit is contained in:
Nikolay Volf 2018-01-23 15:50:28 +03:00 committed by GitHub
commit 88c25b6361
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GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 77 additions and 27 deletions

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@ -6,8 +6,9 @@ use std::fmt;
use std::fs::File;
use wasmi::{
Error as InterpreterError, ModuleInstance, ModuleRef,
Externals, RuntimeValue, FuncRef, TryInto, ModuleImportResolver,
Externals, RuntimeValue, FuncRef, ModuleImportResolver,
FuncInstance, HostError, ImportsBuilder, Signature, ValueType,
RuntimeArgs,
};
#[derive(Debug)]
@ -147,16 +148,16 @@ impl<'a> Externals for Runtime<'a> {
fn invoke_index(
&mut self,
index: usize,
args: &[RuntimeValue],
args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, InterpreterError> {
match index {
SET_FUNC_INDEX => {
let idx: i32 = args[0].try_into().unwrap();
let idx: i32 = args.nth(0)?;
self.game.set(idx, self.player)?;
Ok(None)
}
GET_FUNC_INDEX => {
let idx: i32 = args[0].try_into().unwrap();
let idx: i32 = args.nth(0)?;
let val: i32 = tictactoe::Player::into_i32(self.game.get(idx)?);
Ok(Some(val.into()))
}

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@ -14,7 +14,7 @@ use wasmi::{
MemoryInstance, MemoryRef, ModuleImportResolver, ModuleInstance,
ModuleRef, RuntimeValue, TableInstance, TableRef, ValueType,
load_from_buffer, LoadedModule, Signature, MemoryDescriptor,
TableDescriptor, GlobalDescriptor, FuncInstance,
TableDescriptor, GlobalDescriptor, FuncInstance, RuntimeArgs,
};
#[derive(Debug)]
@ -57,7 +57,7 @@ impl Externals for SpecModule {
fn invoke_index(
&mut self,
index: usize,
args: &[RuntimeValue],
args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, InterpreterError> {
match index {
PRINT_FUNC_INDEX => {

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@ -132,7 +132,7 @@ impl FuncInstance {
let mut interpreter = Interpreter::new(externals);
interpreter.run_function(ctx)
}
InvokeKind::Host(host_func, args) => externals.invoke_index(host_func, args),
InvokeKind::Host(host_func, args) => externals.invoke_index(host_func, args.into()),
}
}
}

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@ -1,7 +1,38 @@
use std::any::TypeId;
use value::RuntimeValue;
use value::{RuntimeValue, TryInto};
use Error;
/// Safe wrapper for list of arguments
#[derive(Debug)]
pub struct RuntimeArgs<'a>(&'a [RuntimeValue]);
impl<'a> From<&'a [RuntimeValue]> for RuntimeArgs<'a> {
fn from(inner: &'a [RuntimeValue]) -> Self {
RuntimeArgs(inner)
}
}
impl<'a> RuntimeArgs<'a> {
/// Extract argument by index `idx` returning error if cast is invalid or not enough arguments
pub fn nth<T>(&self, idx: usize) -> Result<T, Error> where RuntimeValue: TryInto<T, Error> {
Ok(self.nth_value(idx)?.try_into().map_err(|_| Error::Value("Invalid argument cast".to_owned()))?)
}
/// Extract argument as a runtime value by index `idx` returning error is not enough arguments
pub fn nth_value(&self, idx: usize) -> Result<RuntimeValue, Error> {
if self.0.len() <= idx {
return Err(Error::Value("Invalid argument index".to_owned()));
}
Ok(self.0[idx])
}
/// Total number of arguments
pub fn len(&self) -> usize {
self.0.len()
}
}
/// Custom user error.
pub trait HostError: 'static + ::std::fmt::Display + ::std::fmt::Debug {
#[doc(hidden)]
@ -35,7 +66,7 @@ pub trait Externals {
fn invoke_index(
&mut self,
index: usize,
args: &[RuntimeValue],
args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Error>;
}
@ -45,8 +76,28 @@ impl Externals for NopExternals {
fn invoke_index(
&mut self,
_index: usize,
_args: &[RuntimeValue],
_args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Error> {
Err(Error::Trap("invoke index on no-op externals".into()))
}
}
#[cfg(test)]
mod tests {
use value::RuntimeValue;
use super::RuntimeArgs;
#[test]
fn i32_runtime_args() {
let args: RuntimeArgs = (&[RuntimeValue::I32(0)][..]).into();
let val: i32 = args.nth(0).unwrap();
assert_eq!(val, 0);
}
#[test]
fn i64_invalid_arg_cast() {
let args: RuntimeArgs = (&[RuntimeValue::I64(90534534545322)][..]).into();
assert!(args.nth::<i32>(0).is_err());
}
}

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@ -130,7 +130,7 @@ mod tests;
pub use self::memory::{MemoryInstance, MemoryRef};
pub use self::table::{TableInstance, TableRef};
pub use self::value::{RuntimeValue, TryInto};
pub use self::host::{Externals, NopExternals, HostError};
pub use self::host::{Externals, NopExternals, HostError, RuntimeArgs};
pub use self::imports::{ModuleImportResolver, ImportResolver, ImportsBuilder};
pub use self::module::{ModuleInstance, ModuleRef, ExternVal, NotStartedModuleRef};
pub use self::global::{GlobalInstance, GlobalRef};

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@ -1,7 +1,7 @@
use {
Error, Signature, Externals, FuncInstance, FuncRef, HostError, ImportsBuilder,
MemoryInstance, MemoryRef, TableInstance, TableRef, ModuleImportResolver, ModuleInstance, ModuleRef,
RuntimeValue, TryInto, LoadedModule, load_from_buffer, TableDescriptor, MemoryDescriptor,
RuntimeValue, RuntimeArgs, LoadedModule, load_from_buffer, TableDescriptor, MemoryDescriptor,
};
use types::ValueType;
use wabt::wat2wasm;
@ -78,25 +78,24 @@ impl Externals for TestHost {
fn invoke_index(
&mut self,
index: usize,
args: &[RuntimeValue],
args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Error> {
let mut args = args.iter().cloned();
match index {
SUB_FUNC_INDEX => {
let a: i32 = args.next().unwrap().try_into().unwrap();
let b: i32 = args.next().unwrap().try_into().unwrap();
let a: i32 = args.nth(0)?;
let b: i32 = args.nth(1)?;
let result: RuntimeValue = (a - b).into();
Ok(Some(result))
}
ERR_FUNC_INDEX => {
let error_code: u32 = args.next().unwrap().try_into().unwrap();
let error_code = args.nth::<i32>(0)? as u32;
let error = HostErrorWithCode { error_code };
Err(Error::Host(Box::new(error)))
}
INC_MEM_FUNC_INDEX => {
let ptr: u32 = args.next().unwrap().try_into().unwrap();
let ptr = args.nth::<i32>(0)? as u32;
let memory = self.memory.as_ref().expect(
"Function 'inc_mem' expects attached memory",
@ -109,7 +108,7 @@ impl Externals for TestHost {
Ok(None)
}
GET_MEM_FUNC_INDEX => {
let ptr: u32 = args.next().unwrap().try_into().unwrap();
let ptr = args.nth::<i32>(0)? as u32;
let memory = self.memory.as_ref().expect(
"Function 'get_mem' expects attached memory",
@ -120,7 +119,7 @@ impl Externals for TestHost {
Ok(Some(RuntimeValue::I32(buf[0] as i32)))
}
RECURSE_FUNC_INDEX => {
let val: RuntimeValue = args.next().unwrap();
let val = args.nth_value(0)?;
let instance = self.instance
.as_ref()
@ -463,12 +462,11 @@ fn defer_providing_externals() {
fn invoke_index(
&mut self,
index: usize,
args: &[RuntimeValue],
args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Error> {
match index {
INC_FUNC_INDEX => {
let mut args = args.iter().cloned();
let a: u32 = args.next().unwrap().try_into().unwrap();
let a = args.nth::<i32>(0)? as u32;
*self.acc += a;
Ok(None)
}
@ -528,7 +526,7 @@ fn two_envs_one_externals() {
fn invoke_index(
&mut self,
index: usize,
_args: &[RuntimeValue],
_args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Error> {
match index {
PRIVILEGED_FUNC_INDEX => {
@ -648,7 +646,7 @@ fn dynamically_add_host_func() {
fn invoke_index(
&mut self,
index: usize,
_args: &[RuntimeValue],
_args: RuntimeArgs,
) -> Result<Option<RuntimeValue>, Error> {
match index {
ADD_FUNC_FUNC_INDEX => {