Publish with externvals (#81)

* Publish with_externvals constructor.
* Add examples to Signature::new.
* Use Iterators for ExternVal imports
This commit is contained in:
Sergey Pepyakin 2018-03-29 18:43:44 +03:00 committed by GitHub
parent a6b5574704
commit d12a04f8ff
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 102 additions and 24 deletions

View File

@ -213,9 +213,9 @@ impl ModuleInstance {
self.exports.borrow_mut().insert(name.into(), extern_val);
}
fn alloc_module(
fn alloc_module<'i, I: Iterator<Item = &'i ExternVal>>(
loaded_module: &Module,
extern_vals: &[ExternVal]
extern_vals: I,
) -> Result<ModuleRef, Error> {
let module = loaded_module.module();
let instance = ModuleRef(Rc::new(ModuleInstance::default()));
@ -226,18 +226,26 @@ impl ModuleInstance {
}
{
let imports = module.import_section().map(|is| is.entries()).unwrap_or(
&[],
);
if imports.len() != extern_vals.len() {
let mut imports = module
.import_section()
.map(|is| is.entries())
.unwrap_or(&[])
.into_iter();
let mut extern_vals = extern_vals;
loop {
// Iterate on imports and extern_vals in lockstep, a-la `Iterator:zip`.
// We can't use `Iterator::zip` since we want to check if lengths of both iterators are same and
// `Iterator::zip` just returns `None` if either of iterators return `None`.
let (import, extern_val) = match (imports.next(), extern_vals.next()) {
(Some(import), Some(extern_val)) => (import, extern_val),
(None, None) => break,
(Some(_), None) | (None, Some(_)) => {
return Err(Error::Instantiation(
"extern_vals length is not equal to import section entries".to_owned()
"extern_vals length is not equal to import section entries".to_owned(),
));
}
};
for (import, extern_val) in
Iterator::zip(imports.into_iter(), extern_vals.into_iter())
{
match (import.external(), extern_val) {
(&External::Function(fn_type_idx), &ExternVal::Func(ref func)) => {
let expected_fn_type = instance.signature_by_index(fn_type_idx).expect(
@ -383,10 +391,16 @@ impl ModuleInstance {
Ok(instance)
}
fn instantiate_with_externvals(
loaded_module: &Module,
extern_vals: &[ExternVal],
) -> Result<ModuleRef, Error> {
/// Instantiate a module with given [external values][ExternVal] as imports.
///
/// See [new] for details.
///
/// [new]: #method.new
/// [ExternVal]: https://webassembly.github.io/spec/core/exec/runtime.html#syntax-externval
pub fn with_externvals<'a, 'i, I: Iterator<Item = &'i ExternVal>>(
loaded_module: &'a Module,
extern_vals: I,
) -> Result<NotStartedModuleRef<'a>, Error> {
let module = loaded_module.module();
let module_ref = ModuleInstance::alloc_module(loaded_module, extern_vals)?;
@ -433,7 +447,10 @@ impl ModuleInstance {
memory_inst.set(offset_val, data_segment.value())?;
}
Ok(module_ref)
Ok(NotStartedModuleRef {
loaded_module,
instance: module_ref,
})
}
/// Instantiate a [module][`Module`].
@ -535,11 +552,7 @@ impl ModuleInstance {
extern_vals.push(extern_val);
}
let instance = Self::instantiate_with_externvals(loaded_module, &extern_vals)?;
Ok(NotStartedModuleRef {
loaded_module,
instance,
})
Self::with_externvals(loaded_module, extern_vals.iter())
}
/// Invoke exported function by a name.
@ -752,7 +765,9 @@ pub fn check_limits(limits: &ResizableLimits) -> Result<(), Error> {
#[cfg(test)]
mod tests {
use imports::ImportsBuilder;
use super::{ModuleInstance};
use func::FuncInstance;
use types::{Signature, ValueType};
use super::{ModuleInstance, ExternVal};
use tests::parse_wat;
#[should_panic]
@ -770,4 +785,51 @@ mod tests {
&ImportsBuilder::default()
).unwrap().assert_no_start();
}
#[test]
fn imports_provided_by_externvals() {
let module_with_single_import = parse_wat(
r#"
(module
(import "foo" "bar" (func))
)
"#,
);
assert!(
ModuleInstance::with_externvals(
&module_with_single_import,
[
ExternVal::Func(FuncInstance::alloc_host(Signature::new(&[][..], None), 0),)
].iter(),
).is_ok()
);
// externval vector is longer than import count.
assert!(
ModuleInstance::with_externvals(
&module_with_single_import,
[
ExternVal::Func(FuncInstance::alloc_host(Signature::new(&[][..], None), 0)),
ExternVal::Func(FuncInstance::alloc_host(Signature::new(&[][..], None), 1)),
].iter(),
).is_err()
);
// externval vector is shorter than import count.
assert!(ModuleInstance::with_externvals(&module_with_single_import, [].iter(),).is_err());
// externval vector has an unexpected type.
assert!(
ModuleInstance::with_externvals(
&module_with_single_import,
[
ExternVal::Func(FuncInstance::alloc_host(
Signature::new(&[][..], Some(ValueType::I32)),
0
),)
].iter(),
).is_err()
);
}
}

View File

@ -20,6 +20,22 @@ pub struct Signature {
impl Signature {
/// Creates new signature with givens
/// parameter types and optional return type.
///
/// # Examples
///
/// ```rust
/// use wasmi::{Signature, ValueType};
///
/// // s1: (i32) -> ()
/// let s1 = Signature::new(&[ValueType::I32][..], None);
///
/// // s2: () -> i32
/// let s2 = Signature::new(&[][..], Some(ValueType::I32));
///
/// // s3: (I64) -> ()
/// let dynamic_params = vec![ValueType::I64];
/// let s3 = Signature::new(dynamic_params, None);
/// ```
pub fn new<C: Into<Cow<'static, [ValueType]>>>(
params: C,
return_type: Option<ValueType>