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Use Linker in *.wast testing (#1391)

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* Use `Linker` in `*.wast` testing

By default `Linker` disallows shadowing previously defined items, but it
looks like the `*.wast` test suites rely on this so this commit adds a
boolean flag to `Linker` as well indicating whether duplicates are
allowed.

* Review comments

* Add a test with a number of recursive instances

* Deny warnings in doctests

* No tabs
This commit is contained in:
Alex Crichton
2020-03-24 17:37:32 -05:00
committed by GitHub
parent b214804850
commit c241f18b81
7 changed files with 133 additions and 86 deletions
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9
crates/api/src/externals.rs
View File

@@ -557,23 +557,24 @@ impl Table {
/// **unsafe** usages of `Memory`. Do not do these things!
///
/// ```rust
/// # use anyhow::Result;
/// use wasmtime::Memory;
///
/// // NOTE: All code in this function is not safe to execute and may cause
/// // segfaults/undefined behavior at runtime. Do not copy/paste these examples
/// // into production code!
/// unsafe fn unsafe_examples(mem: &Memory) {
/// unsafe fn unsafe_examples(mem: &Memory) -> Result<()> {
/// // First and foremost, any borrow can be invalidated at any time via the
/// // `Memory::grow` function. This can relocate memory which causes any
/// // previous pointer to be possibly invalid now.
/// let pointer: &u8 = &mem.data_unchecked()[0x100];
/// mem.grow(1); // invalidates `pointer`!
/// mem.grow(1)?; // invalidates `pointer`!
/// // println!("{}", *pointer); // FATAL: use-after-free
///
/// // Note that the use-after-free also applies to slices, whether they're
/// // slices of bytes or strings.
/// let slice: &[u8] = &mem.data_unchecked()[0x100..0x102];
/// mem.grow(1); // invalidates `slice`!
/// mem.grow(1)?; // invalidates `slice`!
/// // println!("{:?}", slice); // FATAL: use-after-free
///
/// // Due to the reference-counted nature of `Memory` note that literal
@@ -597,6 +598,8 @@ impl Table {
/// let slice1: &mut [u8] = &mut mem.data_unchecked_mut()[0x100..][..3];
/// let slice2: &mut [u8] = &mut mem.data_unchecked_mut()[0x102..][..4];
/// // println!("{:?} {:?}", slice1, slice2); // FATAL: aliasing mutable pointers
///
/// Ok(())
/// }
/// # fn some_other_function() {}
/// ```

2
crates/api/src/lib.rs
View File

@@ -7,6 +7,8 @@
//! itself for consumption from other languages.
#![deny(missing_docs, intra_doc_link_resolution_failure)]
#![doc(test(attr(deny(warnings))))]
#![doc(test(attr(allow(dead_code, unused_variables, unused_mut))))]
mod externals;
mod frame_info;

69
crates/api/src/linker.rs
View File

@@ -32,11 +32,15 @@ use std::rc::Rc;
/// name `foo` and item name `bar`, so long as they have different function
/// signatures. Currently duplicate memories and tables are not allowed, only
/// one-per-name is allowed.
///
/// Note that allowing duplicates by shadowing the previous definition can be
/// controlled with the [`Linker::allow_shadowing`] method as well.
pub struct Linker {
store: Store,
string2idx: HashMap<Rc<str>, usize>,
strings: Vec<Rc<str>>,
map: HashMap<ImportKey, Extern>,
allow_shadowing: bool,
}
#[derive(Hash, PartialEq, Eq)]
@@ -77,9 +81,40 @@ impl Linker {
map: HashMap::new(),
string2idx: HashMap::new(),
strings: Vec::new(),
allow_shadowing: false,
}
}
/// Configures whether this [`Linker`] will shadow previous duplicate
/// definitions of the same signature.
///
/// By default a [`Linker`] will disallow duplicate definitions of the same
/// signature. This method, however, can be used to instead allow duplicates
/// and have the latest definition take precedence when linking modules.
///
/// # Examples
///
/// ```
/// # use wasmtime::*;
/// # fn main() -> anyhow::Result<()> {
/// # let store = Store::default();
/// let mut linker = Linker::new(&store);
/// linker.func("", "", || {})?;
///
/// // by default, duplicates are disallowed
/// assert!(linker.func("", "", || {}).is_err());
///
/// // but shadowing can be configured to be allowed as well
/// linker.allow_shadowing(true);
/// linker.func("", "", || {})?;
/// # Ok(())
/// # }
/// ```
pub fn allow_shadowing(&mut self, allow: bool) -> &mut Linker {
self.allow_shadowing = allow;
self
}
/// Defines a new item in this [`Linker`].
///
/// This method will add a new definition, by name, to this instance of
@@ -89,8 +124,8 @@ impl Linker {
/// # Errors
///
/// Returns an error if the `module` and `name` already identify an item
/// of the same type as the `item` provided. For more information see the
/// documentation on [`Linker`].
/// of the same type as the `item` provided and if shadowing is disallowed.
/// For more information see the documentation on [`Linker`].
///
/// Also returns an error if `item` comes from a different store than this
/// [`Linker`] was created with.
@@ -104,7 +139,7 @@ impl Linker {
/// let mut linker = Linker::new(&store);
/// let ty = GlobalType::new(ValType::I32, Mutability::Const);
/// let global = Global::new(&store, ty, Val::I32(0x1234))?;
/// linker.define("host", "offset", global);
/// linker.define("host", "offset", global)?;
///
/// let wat = r#"
/// (module
@@ -142,9 +177,9 @@ impl Linker {
///
/// # Errors
///
/// Returns an error if the `module` and `name` already identify a function
/// of the same signature as `func`. For more information see the
/// documentation on [`Linker`].
/// Returns an error if the `module` and `name` already identify an item
/// of the same type as the `item` provided and if shadowing is disallowed.
/// For more information see the documentation on [`Linker`].
///
/// # Examples
///
@@ -190,9 +225,9 @@ impl Linker {
/// # Errors
///
/// Returns an error if the any item is redefined twice in this linker (for
/// example the same `module_name` was already defined), or if `instance`
/// comes from a different [`Store`] than this [`Linker`] originally was
/// created with.
/// example the same `module_name` was already defined) and shadowing is
/// disallowed, or if `instance` comes from a different [`Store`] than this
/// [`Linker`] originally was created with.
///
/// # Examples
///
@@ -238,12 +273,15 @@ impl Linker {
fn insert(&mut self, module: &str, name: &str, ty: &ExternType, item: Extern) -> Result<()> {
let key = self.import_key(module, name, ty);
match self.map.entry(key) {
Entry::Occupied(o) => bail!(
"import of `{}::{}` with as {:?} defined twice",
Entry::Occupied(o) if !self.allow_shadowing => bail!(
"import of `{}::{}` with kind {:?} defined twice",
module,
name,
o.key().kind,
),
Entry::Occupied(mut o) => {
o.insert(item);
}
Entry::Vacant(v) => {
v.insert(item);
}
@@ -337,14 +375,14 @@ impl Linker {
}
if options.len() == 0 {
bail!(
"import of `{}::{}` has not been defined",
"unknown import: `{}::{}` has not been defined",
import.module(),
import.name()
)
}
bail!(
"failed to find import of `{}::{}` with matching signature\n\
"incompatible import type for `{}::{}` specified\n\
desired signature was: {:?}\n\
signatures available:\n\n{}",
import.module(),
@@ -365,4 +403,9 @@ impl Linker {
};
self.map.get(&key)
}
/// Returns the [`Store`] that this linker is connected to.
pub fn store(&self) -> &Store {
&self.store
}
}

31
crates/api/tests/linker.rs
View File

@@ -64,3 +64,34 @@ fn link_twice_bad() -> Result<()> {
assert!(linker.define("", "", table.clone()).is_err());
Ok(())
}
#[test]
fn interposition() -> Result<()> {
let store = Store::default();
let mut linker = Linker::new(&store);
linker.allow_shadowing(true);
let mut module = Module::new(
&store,
r#"(module (func (export "export") (result i32) (i32.const 7)))"#,
)?;
for _ in 0..4 {
let instance = linker.instantiate(&module)?;
linker.define(
"red",
"green",
instance.get_export("export").unwrap().clone(),
)?;
module = Module::new(
&store,
r#"(module
(import "red" "green" (func (result i32)))
(func (export "export") (result i32) (i32.mul (call 0) (i32.const 2)))
)"#,
)?;
}
let instance = linker.instantiate(&module)?;
let func = instance.get_export("export").unwrap().func().unwrap();
let func = func.get0::<i32>()?;
assert_eq!(func()?, 112);
Ok(())
}

2
crates/wast/src/lib.rs
View File

@@ -25,7 +25,7 @@
mod spectest;
mod wast;
pub use crate::spectest::instantiate_spectest;
pub use crate::spectest::link_spectest;
pub use crate::wast::WastContext;
/// Version number of this crate.

63
crates/wast/src/spectest.rs
View File

@@ -1,61 +1,46 @@
use std::collections::HashMap;
use anyhow::Result;
use wasmtime::*;
/// Return an instance implementing the "spectest" interface used in the
/// spec testsuite.
pub fn instantiate_spectest(store: &Store) -> HashMap<&'static str, Extern> {
let mut ret = HashMap::new();
let func = Func::wrap(store, || {});
ret.insert("print", Extern::Func(func));
let func = Func::wrap(store, |val: i32| println!("{}: i32", val));
ret.insert("print_i32", Extern::Func(func));
let func = Func::wrap(store, |val: i64| println!("{}: i64", val));
ret.insert("print_i64", Extern::Func(func));
let func = Func::wrap(store, |val: f32| println!("{}: f32", val));
ret.insert("print_f32", Extern::Func(func));
let func = Func::wrap(store, |val: f64| println!("{}: f64", val));
ret.insert("print_f64", Extern::Func(func));
let func = Func::wrap(store, |i: i32, f: f32| {
pub fn link_spectest(linker: &mut Linker) -> Result<()> {
linker.func("spectest", "print", || {})?;
linker.func("spectest", "print_i32", |val: i32| println!("{}: i32", val))?;
linker.func("spectest", "print_i64", |val: i64| println!("{}: i64", val))?;
linker.func("spectest", "print_f32", |val: f32| println!("{}: f32", val))?;
linker.func("spectest", "print_f64", |val: f64| println!("{}: f64", val))?;
linker.func("spectest", "print_i32_f32", |i: i32, f: f32| {
println!("{}: i32", i);
println!("{}: f32", f);
});
ret.insert("print_i32_f32", Extern::Func(func));
let func = Func::wrap(store, |f1: f64, f2: f64| {
})?;
linker.func("spectest", "print_f64_f64", |f1: f64, f2: f64| {
println!("{}: f64", f1);
println!("{}: f64", f2);
});
ret.insert("print_f64_f64", Extern::Func(func));
})?;
let ty = GlobalType::new(ValType::I32, Mutability::Const);
let g = Global::new(store, ty, Val::I32(666)).unwrap();
ret.insert("global_i32", Extern::Global(g));
let g = Global::new(linker.store(), ty, Val::I32(666))?;
linker.define("spectest", "global_i32", g)?;
let ty = GlobalType::new(ValType::I64, Mutability::Const);
let g = Global::new(store, ty, Val::I64(666)).unwrap();
ret.insert("global_i64", Extern::Global(g));
let g = Global::new(linker.store(), ty, Val::I64(666))?;
linker.define("spectest", "global_i64", g)?;
let ty = GlobalType::new(ValType::F32, Mutability::Const);
let g = Global::new(store, ty, Val::F32(0x4426_8000)).unwrap();
ret.insert("global_f32", Extern::Global(g));
let g = Global::new(linker.store(), ty, Val::F32(0x4426_8000))?;
linker.define("spectest", "global_f32", g)?;
let ty = GlobalType::new(ValType::F64, Mutability::Const);
let g = Global::new(store, ty, Val::F64(0x4084_d000_0000_0000)).unwrap();
ret.insert("global_f64", Extern::Global(g));
let g = Global::new(linker.store(), ty, Val::F64(0x4084_d000_0000_0000))?;
linker.define("spectest", "global_f64", g)?;
let ty = TableType::new(ValType::FuncRef, Limits::new(10, Some(20)));
let table = Table::new(store, ty, Val::AnyRef(AnyRef::Null)).unwrap();
ret.insert("table", Extern::Table(table));
let table = Table::new(linker.store(), ty, Val::AnyRef(AnyRef::Null))?;
linker.define("spectest", "table", table)?;
let ty = MemoryType::new(Limits::new(1, Some(2)));
let memory = Memory::new(store, ty);
ret.insert("memory", Extern::Memory(memory));
let memory = Memory::new(linker.store(), ty);
linker.define("spectest", "memory", memory)?;
return ret;
Ok(())
}

43
crates/wast/src/wast.rs
View File

@@ -1,4 +1,4 @@
use crate::spectest::instantiate_spectest;
use crate::spectest::link_spectest;
use anyhow::{anyhow, bail, Context as _, Result};
use std::collections::HashMap;
use std::path::Path;
@@ -30,8 +30,8 @@ pub struct WastContext {
current: Option<Instance>,
instances: HashMap<String, Instance>,
linker: Linker,
store: Store,
spectest: Option<HashMap<&'static str, Extern>>,
}
enum Outcome<T = Vec<Val>> {
@@ -51,11 +51,16 @@ impl<T> Outcome<T> {
impl WastContext {
/// Construct a new instance of `WastContext`.
pub fn new(store: Store) -> Self {
// Spec tests will redefine the same module/name sometimes, so we need
// to allow shadowing in the linker which picks the most recent
// definition as what to link when linking.
let mut linker = Linker::new(&store);
linker.allow_shadowing(true);
Self {
current: None,
store,
spectest: None,
instances: HashMap::new(),
linker,
store,
}
}
@@ -75,31 +80,7 @@ impl WastContext {
fn instantiate(&self, module: &[u8]) -> Result<Outcome<Instance>> {
let module = Module::new(&self.store, module)?;
let mut imports = Vec::new();
for import in module.imports() {
if import.module() == "spectest" {
let spectest = self
.spectest
.as_ref()
.ok_or_else(|| anyhow!("spectest module isn't instantiated"))?;
let export = spectest
.get(import.name())
.ok_or_else(|| anyhow!("unknown import `spectest::{}`", import.name()))?;
imports.push(export.clone());
continue;
}
let instance = self
.instances
.get(import.module())
.ok_or_else(|| anyhow!("no module named `{}`", import.module()))?;
let export = instance
.get_export(import.name())
.ok_or_else(|| anyhow!("unknown import `{}::{}`", import.name(), import.module()))?
.clone();
imports.push(export);
}
let instance = match Instance::new(&module, &imports) {
let instance = match self.linker.instantiate(&module) {
Ok(i) => i,
Err(e) => return e.downcast::<Trap>().map(Outcome::Trap),
};
@@ -108,7 +89,7 @@ impl WastContext {
/// Register "spectest" which is used by the spec testsuite.
pub fn register_spectest(&mut self) -> Result<()> {
self.spectest = Some(instantiate_spectest(&self.store));
link_spectest(&mut self.linker)?;
Ok(())
}
@@ -145,6 +126,7 @@ impl WastContext {
};
if let Some(name) = instance_name {
self.instances.insert(name.to_string(), instance.clone());
self.linker.instance(name, &instance)?;
}
self.current = Some(instance);
Ok(())
@@ -153,6 +135,7 @@ impl WastContext {
/// Register an instance to make it available for performing actions.
fn register(&mut self, name: Option<&str>, as_name: &str) -> Result<()> {
let instance = self.get_instance(name)?.clone();
self.linker.instance(as_name, &instance)?;
self.instances.insert(as_name.to_string(), instance);
Ok(())
}