fix(wasmtime): fix --no-default-features with async (#11244)

* fix(wasmtime): fix `--no-default-features` with async

Currently, building `wasmtime` via:

```
$ cargo build -p wasmtime --no-default-features --features component-model-async
```

fails with:

```
error[E0432]: unresolved import `wasmtime_environ::fact`
  --> crates/wasmtime/src/runtime/component/concurrent.rs:88:36
   |
88 | use wasmtime_environ::{PrimaryMap, fact};
   |                                    ^^^^ no `fact` in the root
   |
note: found an item that was configured out
  --> /Users/rvolosatovs/src/github.com/bytecodealliance/wasmtime/crates/environ/src/lib.rs:72:9
   |
72 | pub mod fact;
   |         ^^^^
note: the item is gated here
  --> /Users/rvolosatovs/src/github.com/bytecodealliance/wasmtime/crates/environ/src/lib.rs:71:1
   |
71 | #[cfg(all(feature = "component-model", feature = "compile"))]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```

in order to avoid the need for `component-model-async` feature to enable
`wasmtime-environ/compile`, promote `START_FLAG_ASYNC_CALLEE` to
crate-level const

Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>

* ci: test `component-model-async` with no default features

Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>

* refactor: move async const to `component`

Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>

---------

Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>

Author: rvolosatovs

.github/workflows/main.yml

@@ -327,6 +327,7 @@ jobs:
               -p wasmtime --no-default-features --features pooling-allocator
               -p wasmtime --no-default-features --features cranelift
               -p wasmtime --no-default-features --features component-model
+              -p wasmtime --no-default-features --features component-model-async
               -p wasmtime --no-default-features --features runtime,component-model
               -p wasmtime --no-default-features --features cranelift,wat,async,std,cache
               -p wasmtime --no-default-features --features winch

crates/environ/src/component.rs

@@ -44,6 +44,13 @@ pub const PREPARE_ASYNC_NO_RESULT: u32 = u32::MAX;
 /// pointer.
 pub const PREPARE_ASYNC_WITH_RESULT: u32 = u32::MAX - 1;
 
+/// Bit flag for indicating async-lifted exports
+///
+/// This flag may be passed to the `async-start` built-in function (which is
+/// called from both async->async and async->sync adapters) to indicate that the
+/// callee is an async-lifted export.
+pub const START_FLAG_ASYNC_CALLEE: i32 = 1 << 0;
+
 mod artifacts;
 mod info;
 mod names;

crates/environ/src/fact.rs

@@ -36,13 +36,6 @@ mod trampoline;
 mod transcode;
 mod traps;
 
-/// Bit flag for indicating async-lifted exports
-///
-/// This flag may be passed to the `async-start` built-in function (which is
-/// called from both async->async and async->sync adapters) to indicate that the
-/// callee is an async-lifted export.
-pub const START_FLAG_ASYNC_CALLEE: i32 = 1 << 0;
-
 /// Fixed parameter types for the `prepare_call` built-in function.
 ///
 /// Note that `prepare_call` also takes a variable number of parameters in

crates/environ/src/fact/trampoline.rs

@@ -18,10 +18,10 @@
 use crate::component::{
     CanonicalAbiInfo, ComponentTypesBuilder, FLAG_MAY_ENTER, FLAG_MAY_LEAVE, FixedEncoding as FE,
     FlatType, InterfaceType, MAX_FLAT_ASYNC_PARAMS, MAX_FLAT_PARAMS, PREPARE_ASYNC_NO_RESULT,
-    PREPARE_ASYNC_WITH_RESULT, StringEncoding, Transcode, TypeComponentLocalErrorContextTableIndex,
-    TypeEnumIndex, TypeFlagsIndex, TypeFutureTableIndex, TypeListIndex, TypeOptionIndex,
-    TypeRecordIndex, TypeResourceTableIndex, TypeResultIndex, TypeStreamTableIndex, TypeTupleIndex,
-    TypeVariantIndex, VariantInfo,
+    PREPARE_ASYNC_WITH_RESULT, START_FLAG_ASYNC_CALLEE, StringEncoding, Transcode,
+    TypeComponentLocalErrorContextTableIndex, TypeEnumIndex, TypeFlagsIndex, TypeFutureTableIndex,
+    TypeListIndex, TypeOptionIndex, TypeRecordIndex, TypeResourceTableIndex, TypeResultIndex,
+    TypeStreamTableIndex, TypeTupleIndex, TypeVariantIndex, VariantInfo,
 };
 use crate::fact::signature::Signature;
 use crate::fact::transcode::Transcoder;
@@ -494,7 +494,7 @@ impl<'a, 'b> Compiler<'a, 'b> {
         // callback) or zero (if there's no callback).  We conservatively use
         // one here to ensure the host provides room for the result, if any.
         self.instruction(I32Const(1));
-        self.instruction(I32Const(super::START_FLAG_ASYNC_CALLEE));
+        self.instruction(I32Const(START_FLAG_ASYNC_CALLEE));
         self.instruction(Call(start_call.as_u32()));
 
         self.finish()

crates/wasmtime/src/runtime/component/concurrent.rs

@@ -79,13 +79,13 @@ use std::sync::Mutex;
 use std::task::{Context, Poll, Waker};
 use std::vec::Vec;
 use table::{Table, TableDebug, TableError, TableId};
+use wasmtime_environ::PrimaryMap;
 use wasmtime_environ::component::{
     ExportIndex, MAX_FLAT_PARAMS, MAX_FLAT_RESULTS, PREPARE_ASYNC_NO_RESULT,
     PREPARE_ASYNC_WITH_RESULT, RuntimeComponentInstanceIndex, StringEncoding,
     TypeComponentGlobalErrorContextTableIndex, TypeComponentLocalErrorContextTableIndex,
     TypeFutureTableIndex, TypeStreamTableIndex, TypeTupleIndex,
 };
-use wasmtime_environ::{PrimaryMap, fact};
 
 pub use abort::AbortHandle;
 pub use futures_and_streams::{
@@ -194,7 +194,7 @@ mod callback_code {
 /// A flag indicating that the callee is an async-lowered export.
 ///
 /// This may be passed to the `async-start` intrinsic from a fused adapter.
-const START_FLAG_ASYNC_CALLEE: u32 = fact::START_FLAG_ASYNC_CALLEE as u32;
+const START_FLAG_ASYNC_CALLEE: u32 = wasmtime_environ::component::START_FLAG_ASYNC_CALLEE as u32;
 
 /// Provides access to either store data (via the `get` method) or the store
 /// itself (via [`AsContext`]/[`AsContextMut`]), as well as the component