T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
Files
5a006674c39b5003128b78bc9a92f8edc99ae45c
wasmtime/tests/all/component_model/import.rs
Alex Crichton 2afaac5181 Return anyhow::Error from host functions instead of Trap, redesign Trap (#5149) 
* Return `anyhow::Error` from host functions instead of `Trap`

This commit refactors how errors are modeled when returned from host
functions and additionally refactors how custom errors work with `Trap`.
At a high level functions in Wasmtime that previously worked with
`Result<T, Trap>` now work with `Result<T>` instead where the error is
`anyhow::Error`. This includes functions such as:

* Host-defined functions in a `Linker<T>`
* `TypedFunc::call`
* Host-related callbacks like call hooks

Errors are now modeled primarily as `anyhow::Error` throughout Wasmtime.
This subsequently removes the need for `Trap` to have the ability to
represent all host-defined errors as it previously did. Consequently the
`From` implementations for any error into a `Trap` have been removed
here and the only embedder-defined way to create a `Trap` is to use
`Trap::new` with a custom string.

After this commit the distinction between a `Trap` and a host error is
the wasm backtrace that it contains. Previously all errors in host
functions would flow through a `Trap` and get a wasm backtrace attached
to them, but now this only happens if a `Trap` itself is created meaning
that arbitrary host-defined errors flowing from a host import to the
other side won't get backtraces attached. Some internals of Wasmtime
itself were updated or preserved to use `Trap::new` to capture a
backtrace where it seemed useful, such as when fuel runs out.

The main motivation for this commit is that it now enables hosts to
thread a concrete error type from a host function all the way through to
where a wasm function was invoked. Previously this could not be done
since the host error was wrapped in a `Trap` that didn't provide the
ability to get at the internals.

A consequence of this commit is that when a host error is returned that
isn't a `Trap` we'll capture a backtrace and then won't have a `Trap` to
attach it to. To avoid losing the contextual information this commit
uses the `Error::context` method to attach the backtrace as contextual
information to ensure that the backtrace is itself not lost.

This is a breaking change for likely all users of Wasmtime, but it's
hoped to be a relatively minor change to workaround. Most use cases can
likely change `-> Result<T, Trap>` to `-> Result<T>` and otherwise
explicit creation of a `Trap` is largely no longer necessary.

* Fix some doc links

* add some tests and make a backtrace type public (#55)

* Trap: avoid a trailing newline in the Display impl

which in turn ends up with three newlines between the end of the
backtrace and the `Caused by` in the anyhow Debug impl

* make BacktraceContext pub, and add tests showing downcasting behavior of anyhow::Error to traps or backtraces

* Remove now-unnecesary `Trap` downcasts in `Linker::module`

* Fix test output expectations

* Remove `Trap::i32_exit`

This commit removes special-handling in the `wasmtime::Trap` type for
the i32 exit code required by WASI. This is now instead modeled as a
specific `I32Exit` error type in the `wasmtime-wasi` crate which is
returned by the `proc_exit` hostcall. Embedders which previously tested
for i32 exits now downcast to the `I32Exit` value.

* Remove the `Trap::new` constructor

This commit removes the ability to create a trap with an arbitrary error
message. The purpose of this commit is to continue the prior trend of
leaning into the `anyhow::Error` type instead of trying to recreate it
with `Trap`. A subsequent simplification to `Trap` after this commit is
that `Trap` will simply be an `enum` of trap codes with no extra
information. This commit is doubly-motivated by the desire to always use
the new `BacktraceContext` type instead of sometimes using that and
sometimes using `Trap`.

Most of the changes here were around updating `Trap::new` calls to
`bail!` calls instead. Tests which assert particular error messages
additionally often needed to use the `:?` formatter instead of the `{}`
formatter because the prior formats the whole `anyhow::Error` and the
latter only formats the top-most error, which now contains the
backtrace.

* Merge `Trap` and `TrapCode`

With prior refactorings there's no more need for `Trap` to be opaque or
otherwise contain a backtrace. This commit parse down `Trap` to simply
an `enum` which was the old `TrapCode`. All various tests and such were
updated to handle this.

The main consequence of this commit is that all errors have a
`BacktraceContext` context attached to them. This unfortunately means
that the backtrace is printed first before the error message or trap
code, but given all the prior simplifications that seems worth it at
this time.

* Rename `BacktraceContext` to `WasmBacktrace`

This feels like a better name given how this has turned out, and
additionally this commit removes having both `WasmBacktrace` and
`BacktraceContext`.

* Soup up documentation for errors and traps

* Fix build of the C API

Co-authored-by: Pat Hickey <pat@moreproductive.org>
2022-11-02 16:29:31 +00:00

818 lines
23 KiB
Rust
Raw Blame History

use super::REALLOC_AND_FREE;
use anyhow::Result;
use std::ops::Deref;
use wasmtime::component::*;
use wasmtime::{Store, StoreContextMut, WasmBacktrace};
#[test]
fn can_compile() -> Result<()> {
let engine = super::engine();
let libc = r#"
(core module $libc
(memory (export "memory") 1)
(func (export "realloc") (param i32 i32 i32 i32) (result i32)
unreachable)
)
(core instance $libc (instantiate $libc))
"#;
Component::new(
&engine,
r#"(component
(import "" (func $f))
(core func (canon lower (func $f)))
)"#,
)?;
Component::new(
&engine,
format!(
r#"(component
(import "" (func $f (param "a" string)))
{libc}
(core func (canon lower (func $f) (memory $libc "memory") (realloc (func $libc "realloc"))))
)"#
),
)?;
Component::new(
&engine,
format!(
r#"(component
(import "f1" (func $f1 (param "a" string) (result string)))
{libc}
(core func (canon lower (func $f1) (memory $libc "memory") (realloc (func $libc "realloc"))))
(import "f2" (func $f2 (param "a" u32) (result (list u8))))
(core instance $libc2 (instantiate $libc))
(core func (canon lower (func $f2) (memory $libc2 "memory") (realloc (func $libc2 "realloc"))))
(core func (canon lower (func $f1) (memory $libc2 "memory") (realloc (func $libc2 "realloc"))))
(core func (canon lower (func $f2) (memory $libc "memory") (realloc (func $libc "realloc"))))
)"#
),
)?;
Component::new(
&engine,
format!(
r#"(component
(import "log" (func $log (param "a" string)))
{libc}
(core func $log_lower (canon lower (func $log) (memory $libc "memory") (realloc (func $libc "realloc"))))
(core module $logger
(import "host" "log" (func $log (param i32 i32)))
(import "libc" "memory" (memory 1))
(func (export "call")
i32.const 0
i32.const 0
call $log)
)
(core instance $logger (instantiate $logger
(with "host" (instance (export "log" (func $log_lower))))
(with "libc" (instance $libc))
))
(func (export "call")
(canon lift (core func $logger "call"))
)
)"#
),
)?;
Ok(())
}
#[test]
fn simple() -> Result<()> {
let component = r#"
(component
(import "" (func $log (param "a" string)))
(core module $libc
(memory (export "memory") 1)
(func (export "realloc") (param i32 i32 i32 i32) (result i32)
unreachable)
)
(core instance $libc (instantiate $libc))
(core func $log_lower
(canon lower (func $log) (memory $libc "memory") (realloc (func $libc "realloc")))
)
(core module $m
(import "libc" "memory" (memory 1))
(import "host" "log" (func $log (param i32 i32)))
(func (export "call")
i32.const 5
i32.const 11
call $log)
(data (i32.const 5) "hello world")
)
(core instance $i (instantiate $m
(with "libc" (instance $libc))
(with "host" (instance (export "log" (func $log_lower))))
))
(func (export "call")
(canon lift (core func $i "call"))
)
)
"#;
let engine = super::engine();
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, None);
assert!(store.data().is_none());
// First, test the static API
let mut linker = Linker::new(&engine);
linker.root().func_wrap(
"",
|mut store: StoreContextMut<'_, Option<String>>, (arg,): (WasmStr,)| -> Result<_> {
let s = arg.to_str(&store)?.to_string();
assert!(store.data().is_none());
*store.data_mut() = Some(s);
Ok(())
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
instance
.get_typed_func::<(), (), _>(&mut store, "call")?
.call(&mut store, ())?;
assert_eq!(store.data().as_ref().unwrap(), "hello world");
// Next, test the dynamic API
*store.data_mut() = None;
let mut linker = Linker::new(&engine);
linker.root().func_new(
&component,
"",
|mut store: StoreContextMut<'_, Option<String>>, args, _results| {
if let Val::String(s) = &args[0] {
assert!(store.data().is_none());
*store.data_mut() = Some(s.to_string());
Ok(())
} else {
panic!()
}
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
instance
.get_func(&mut store, "call")
.unwrap()
.call(&mut store, &[], &mut [])?;
assert_eq!(store.data().as_ref().unwrap(), "hello world");
Ok(())
}
#[test]
fn attempt_to_leave_during_malloc() -> Result<()> {
let component = r#"
(component
(import "thunk" (func $thunk))
(import "ret-string" (func $ret_string (result string)))
(core module $host_shim
(table (export "table") 2 funcref)
(func $shim_thunk (export "thunk")
i32.const 0
call_indirect)
(func $shim_ret_string (export "ret-string") (param i32)
local.get 0
i32.const 1
call_indirect (param i32))
)
(core instance $host_shim (instantiate $host_shim))
(core module $m
(import "host" "thunk" (func $thunk))
(import "host" "ret-string" (func $ret_string (param i32)))
(memory (export "memory") 1)
(func $realloc (export "realloc") (param i32 i32 i32 i32) (result i32)
call $thunk
unreachable)
(func $run (export "run")
i32.const 8
call $ret_string)
(func (export "take-string") (param i32 i32)
unreachable)
)
(core instance $m (instantiate $m (with "host" (instance $host_shim))))
(core module $host_shim_filler_inner
(import "shim" "table" (table 2 funcref))
(import "host" "thunk" (func $thunk))
(import "host" "ret-string" (func $ret_string (param i32)))
(elem (i32.const 0) $thunk $ret_string)
)
(core func $thunk_lower
(canon lower (func $thunk) (memory $m "memory") (realloc (func $m "realloc")))
)
(core func $ret_string_lower
(canon lower (func $ret_string) (memory $m "memory") (realloc (func $m "realloc")))
)
(core instance (instantiate $host_shim_filler_inner
(with "shim" (instance $host_shim))
(with "host" (instance
(export "thunk" (func $thunk_lower))
(export "ret-string" (func $ret_string_lower))
))
))
(func (export "run")
(canon lift (core func $m "run"))
)
(func (export "take-string") (param "a" string)
(canon lift (core func $m "take-string") (memory $m "memory") (realloc (func $m "realloc")))
)
)
"#;
let engine = super::engine();
let mut linker = Linker::new(&engine);
linker.root().func_wrap("thunk", |_, _: ()| -> Result<()> {
panic!("should not get here")
})?;
linker
.root()
.func_wrap("ret-string", |_, _: ()| -> Result<_> {
Ok(("hello".to_string(),))
})?;
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, ());
// Assert that during a host import if we return values to wasm that a trap
// happens if we try to leave the instance.
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "run")?
.call(&mut store, ())
.unwrap_err();
assert!(
format!("{trap:?}").contains("cannot leave component instance"),
"bad trap: {trap:?}",
);
let trace = trap.downcast_ref::<WasmBacktrace>().unwrap().frames();
assert_eq!(trace.len(), 4);
// This was our entry point...
assert_eq!(trace[3].module_name(), Some("m"));
assert_eq!(trace[3].func_name(), Some("run"));
// ... which called an imported function which ends up being originally
// defined by the shim instance. The shim instance then does an indirect
// call through a table which goes to the `canon.lower`'d host function
assert_eq!(trace[2].module_name(), Some("host_shim"));
assert_eq!(trace[2].func_name(), Some("shim_ret_string"));
// ... and the lowered host function will call realloc to allocate space for
// the result
assert_eq!(trace[1].module_name(), Some("m"));
assert_eq!(trace[1].func_name(), Some("realloc"));
// ... but realloc calls the shim instance and tries to exit the
// component, triggering a dynamic trap
assert_eq!(trace[0].module_name(), Some("host_shim"));
assert_eq!(trace[0].func_name(), Some("shim_thunk"));
// In addition to the above trap also ensure that when we enter a wasm
// component if we try to leave while lowering then that's also a dynamic
// trap.
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(&str,), (), _>(&mut store, "take-string")?
.call(&mut store, ("x",))
.unwrap_err();
assert!(
format!("{trap:?}").contains("cannot leave component instance"),
"bad trap: {trap:?}",
);
Ok(())
}
#[test]
fn attempt_to_reenter_during_host() -> Result<()> {
let component = r#"
(component
(import "thunk" (func $thunk))
(core func $thunk_lower (canon lower (func $thunk)))
(core module $m
(import "host" "thunk" (func $thunk))
(func $run (export "run")
call $thunk)
)
(core instance $m (instantiate $m
(with "host" (instance (export "thunk" (func $thunk_lower))))
))
(func (export "run")
(canon lift (core func $m "run"))
)
)
"#;
let engine = super::engine();
let component = Component::new(&engine, component)?;
// First, test the static API
struct StaticState {
func: Option<TypedFunc<(), ()>>,
}
let mut store = Store::new(&engine, StaticState { func: None });
let mut linker = Linker::new(&engine);
linker.root().func_wrap(
"thunk",
|mut store: StoreContextMut<'_, StaticState>, _: ()| -> Result<()> {
let func = store.data_mut().func.take().unwrap();
let trap = func.call(&mut store, ()).unwrap_err();
assert!(
format!("{trap:?}").contains("cannot reenter component instance"),
"bad trap: {trap:?}",
);
Ok(())
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
let func = instance.get_typed_func::<(), (), _>(&mut store, "run")?;
store.data_mut().func = Some(func);
func.call(&mut store, ())?;
// Next, test the dynamic API
struct DynamicState {
func: Option<Func>,
}
let mut store = Store::new(&engine, DynamicState { func: None });
let mut linker = Linker::new(&engine);
linker.root().func_new(
&component,
"thunk",
|mut store: StoreContextMut<'_, DynamicState>, _, _| {
let func = store.data_mut().func.take().unwrap();
let trap = func.call(&mut store, &[], &mut []).unwrap_err();
assert!(
format!("{trap:?}").contains("cannot reenter component instance"),
"bad trap: {trap:?}",
);
Ok(())
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
let func = instance.get_func(&mut store, "run").unwrap();
store.data_mut().func = Some(func);
func.call(&mut store, &[], &mut [])?;
Ok(())
}
#[test]
fn stack_and_heap_args_and_rets() -> Result<()> {
let component = format!(
r#"
(component
(type $many_params (tuple
string string string string
string string string string
string))
(import "f1" (func $f1 (param "a" u32) (result u32)))
(import "f2" (func $f2 (param "a" $many_params) (result u32)))
(import "f3" (func $f3 (param "a" u32) (result string)))
(import "f4" (func $f4 (param "a" $many_params) (result string)))
(core module $libc
{REALLOC_AND_FREE}
(memory (export "memory") 1)
)
(core instance $libc (instantiate (module $libc)))
(core func $f1_lower (canon lower (func $f1) (memory $libc "memory") (realloc (func $libc "realloc"))))
(core func $f2_lower (canon lower (func $f2) (memory $libc "memory") (realloc (func $libc "realloc"))))
(core func $f3_lower (canon lower (func $f3) (memory $libc "memory") (realloc (func $libc "realloc"))))
(core func $f4_lower (canon lower (func $f4) (memory $libc "memory") (realloc (func $libc "realloc"))))
(core module $m
(import "host" "f1" (func $f1 (param i32) (result i32)))
(import "host" "f2" (func $f2 (param i32) (result i32)))
(import "host" "f3" (func $f3 (param i32 i32)))
(import "host" "f4" (func $f4 (param i32 i32)))
(import "libc" "memory" (memory 1))
(func $run (export "run")
block
i32.const 1
call $f1
i32.const 2
i32.eq
br_if 0
unreachable
end
block
call $allocate_empty_strings
call $f2
i32.const 3
i32.eq
br_if 0
unreachable
end
block
i32.const 8
i32.const 16000
call $f3
(call $validate_string_ret (i32.const 16000))
end
block
call $allocate_empty_strings
i32.const 20000
call $f4
(call $validate_string_ret (i32.const 20000))
end
)
(func $allocate_empty_strings (result i32)
(local $ret i32)
(local $offset i32)
(local $cnt i32)
(local.set $ret (i32.const 8000))
(local.set $cnt (i32.const 9))
loop
(call $setup_str (i32.add (local.get $ret) (local.get $offset)))
(local.set $offset (i32.add (local.get $offset) (i32.const 8)))
(local.tee $cnt (i32.add (local.get $cnt) (i32.const -1)))
br_if 0
end
local.get $ret
)
(func $setup_str (param $addr i32)
(i32.store offset=0 (local.get $addr) (i32.const 1000))
(i32.store offset=4 (local.get $addr) (i32.const 3))
)
(func $validate_string_ret (param $addr i32)
(local $base i32)
(local $len i32)
(local.set $base (i32.load (local.get $addr)))
(local.set $len (i32.load offset=4 (local.get $addr)))
block
local.get $len
i32.const 3
i32.eq
br_if 0
unreachable
end
(i32.load8_u offset=0 (local.get $base))
i32.const 120 ;; 'x'
i32.ne
if unreachable end
(i32.load8_u offset=1 (local.get $base))
i32.const 121 ;; 'y'
i32.ne
if unreachable end
(i32.load8_u offset=2 (local.get $base))
i32.const 122 ;; 'z'
i32.ne
if unreachable end
)
(data (i32.const 1000) "abc")
)
(core instance $m (instantiate $m
(with "libc" (instance $libc))
(with "host" (instance
(export "f1" (func $f1_lower))
(export "f2" (func $f2_lower))
(export "f3" (func $f3_lower))
(export "f4" (func $f4_lower))
))
))
(func (export "run")
(canon lift (core func $m "run"))
)
)
"#
);
let engine = super::engine();
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, ());
// First, test the static API
let mut linker = Linker::new(&engine);
linker
.root()
.func_wrap("f1", |_, (x,): (u32,)| -> Result<(u32,)> {
assert_eq!(x, 1);
Ok((2,))
})?;
linker.root().func_wrap(
"f2",
|cx: StoreContextMut<'_, ()>,
(arg,): ((
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
),)|
-> Result<(u32,)> {
assert_eq!(arg.0.to_str(&cx).unwrap(), "abc");
Ok((3,))
},
)?;
linker
.root()
.func_wrap("f3", |_, (arg,): (u32,)| -> Result<(String,)> {
assert_eq!(arg, 8);
Ok(("xyz".to_string(),))
})?;
linker.root().func_wrap(
"f4",
|cx: StoreContextMut<'_, ()>,
(arg,): ((
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
),)|
-> Result<(String,)> {
assert_eq!(arg.0.to_str(&cx).unwrap(), "abc");
Ok(("xyz".to_string(),))
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
instance
.get_typed_func::<(), (), _>(&mut store, "run")?
.call(&mut store, ())?;
// Next, test the dynamic API
let mut linker = Linker::new(&engine);
linker
.root()
.func_new(&component, "f1", |_, args, results| {
if let Val::U32(x) = &args[0] {
assert_eq!(*x, 1);
results[0] = Val::U32(2);
Ok(())
} else {
panic!()
}
})?;
linker
.root()
.func_new(&component, "f2", |_, args, results| {
if let Val::Tuple(tuple) = &args[0] {
if let Val::String(s) = &tuple.values()[0] {
assert_eq!(s.deref(), "abc");
results[0] = Val::U32(3);
Ok(())
} else {
panic!()
}
} else {
panic!()
}
})?;
linker
.root()
.func_new(&component, "f3", |_, args, results| {
if let Val::U32(x) = &args[0] {
assert_eq!(*x, 8);
results[0] = Val::String("xyz".into());
Ok(())
} else {
panic!();
}
})?;
linker
.root()
.func_new(&component, "f4", |_, args, results| {
if let Val::Tuple(tuple) = &args[0] {
if let Val::String(s) = &tuple.values()[0] {
assert_eq!(s.deref(), "abc");
results[0] = Val::String("xyz".into());
Ok(())
} else {
panic!()
}
} else {
panic!()
}
})?;
let instance = linker.instantiate(&mut store, &component)?;
instance
.get_func(&mut store, "run")
.unwrap()
.call(&mut store, &[], &mut [])?;
Ok(())
}
#[test]
fn bad_import_alignment() -> Result<()> {
let component = format!(
r#"
(component
(import "unaligned-retptr" (func $unaligned_retptr (result string)))
(type $many_arg (tuple
string string string string
string string string string
string
))
(import "unaligned-argptr" (func $unaligned_argptr (param "a" $many_arg)))
(core module $libc_panic
(memory (export "memory") 1)
(func (export "realloc") (param i32 i32 i32 i32) (result i32)
unreachable)
)
(core instance $libc_panic (instantiate $libc_panic))
(core func $unaligned_retptr_lower
(canon lower (func $unaligned_retptr) (memory $libc_panic "memory") (realloc (func $libc_panic "realloc")))
)
(core func $unaligned_argptr_lower
(canon lower (func $unaligned_argptr) (memory $libc_panic "memory") (realloc (func $libc_panic "realloc")))
)
(core module $m
(import "host" "unaligned-retptr" (func $unaligned_retptr (param i32)))
(import "host" "unaligned-argptr" (func $unaligned_argptr (param i32)))
(func (export "unaligned-retptr")
(call $unaligned_retptr (i32.const 1)))
(func (export "unaligned-argptr")
(call $unaligned_argptr (i32.const 1)))
)
(core instance $m (instantiate $m
(with "host" (instance
(export "unaligned-retptr" (func $unaligned_retptr_lower))
(export "unaligned-argptr" (func $unaligned_argptr_lower))
))
))
(func (export "unaligned-retptr")
(canon lift (core func $m "unaligned-retptr"))
)
(func (export "unaligned-argptr")
(canon lift (core func $m "unaligned-argptr"))
)
)
"#
);
let engine = super::engine();
let mut linker = Linker::new(&engine);
linker
.root()
.func_wrap("unaligned-retptr", |_, _: ()| -> Result<(String,)> {
Ok((String::new(),))
})?;
linker.root().func_wrap(
"unaligned-argptr",
|_,
_: ((
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
WasmStr,
),)|
-> Result<()> { unreachable!() },
)?;
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, ());
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "unaligned-retptr")?
.call(&mut store, ())
.unwrap_err();
assert!(
format!("{:?}", trap).contains("pointer not aligned"),
"{}",
trap
);
let trap = linker
.instantiate(&mut store, &component)?
.get_typed_func::<(), (), _>(&mut store, "unaligned-argptr")?
.call(&mut store, ())
.unwrap_err();
assert!(
format!("{:?}", trap).contains("pointer not aligned"),
"{}",
trap
);
Ok(())
}
#[test]
fn no_actual_wasm_code() -> Result<()> {
let component = r#"
(component
(import "f" (func $f))
(core func $f_lower
(canon lower (func $f))
)
(core module $m
(import "" "" (func $f))
(export "f" (func $f))
)
(core instance $i (instantiate $m
(with "" (instance
(export "" (func $f_lower))
))
))
(func (export "thunk")
(canon lift
(core func $i "f")
)
)
)
"#;
let engine = super::engine();
let component = Component::new(&engine, component)?;
let mut store = Store::new(&engine, 0);
// First, test the static API
let mut linker = Linker::new(&engine);
linker.root().func_wrap(
"f",
|mut store: StoreContextMut<'_, u32>, _: ()| -> Result<()> {
*store.data_mut() += 1;
Ok(())
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
let thunk = instance.get_typed_func::<(), (), _>(&mut store, "thunk")?;
assert_eq!(*store.data(), 0);
thunk.call(&mut store, ())?;
assert_eq!(*store.data(), 1);
// Next, test the dynamic API
*store.data_mut() = 0;
let mut linker = Linker::new(&engine);
linker.root().func_new(
&component,
"f",
|mut store: StoreContextMut<'_, u32>, _, _| {
*store.data_mut() += 1;
Ok(())
},
)?;
let instance = linker.instantiate(&mut store, &component)?;
let thunk = instance.get_func(&mut store, "thunk").unwrap();
assert_eq!(*store.data(), 0);
thunk.call(&mut store, &[], &mut [])?;
assert_eq!(*store.data(), 1);
Ok(())
}
Reference in New Issue View Git Blame Copy Permalink