Add anyhow stuff to our internal wasmtime crate prelude (#8804)

* Add `anyhow` stuff to our internal `wasmtime` crate prelude

We use it basically everywhere and it is annoying to have to import.

I also did an audit of existing `use` statements and removed the now-redundant
ones and replaced one-off imports with usage of the prelude, so that the prelude
is available by default in more places.

* Fix `cargo doc`

Author: fitzgen

crates/wasmtime/src/compile.rs

@@ -24,7 +24,6 @@
 
 use crate::prelude::*;
 use crate::Engine;
-use anyhow::{Context, Result};
 use std::{
     any::Any,
     borrow::Cow,

crates/wasmtime/src/compile/code_builder.rs

@@ -1,6 +1,5 @@
 use crate::prelude::*;
 use crate::Engine;
-use anyhow::{anyhow, bail, Context, Result};
 use std::borrow::Cow;
 use std::path::Path;
 

crates/wasmtime/src/compile/runtime.rs

@@ -1,9 +1,9 @@
 use crate::compile::HashedEngineCompileEnv;
 #[cfg(feature = "component-model")]
 use crate::component::Component;
+use crate::prelude::*;
 use crate::runtime::vm::MmapVec;
 use crate::{CodeBuilder, CodeMemory, Engine, Module};
-use anyhow::{Context, Error, Result};
 use object::write::WritableBuffer;
 use std::sync::Arc;
 use wasmtime_environ::{FinishedObject, ObjectBuilder, ObjectKind};

crates/wasmtime/src/config.rs

@@ -1,6 +1,5 @@
 use crate::prelude::*;
 use alloc::sync::Arc;
-use anyhow::{bail, ensure, Result};
 use core::fmt;
 use core::str::FromStr;
 use hashbrown::{HashMap, HashSet};

crates/wasmtime/src/engine.rs

@@ -6,7 +6,6 @@ use crate::runtime::vm::GcRuntime;
 use crate::sync::OnceLock;
 use crate::Config;
 use alloc::sync::Arc;
-use anyhow::{Context, Result};
 use core::sync::atomic::{AtomicU64, Ordering};
 #[cfg(any(feature = "cranelift", feature = "winch"))]
 use object::write::{Object, StandardSegment};

crates/wasmtime/src/engine/serialization.rs

@@ -23,7 +23,6 @@
 
 use crate::prelude::*;
 use crate::{Engine, ModuleVersionStrategy, Precompiled};
-use anyhow::{anyhow, bail, ensure, Context, Result};
 use core::str::FromStr;
 use object::endian::NativeEndian;
 #[cfg(any(feature = "cranelift", feature = "winch"))]

crates/wasmtime/src/lib.rs

@@ -281,7 +281,11 @@
 extern crate std;
 extern crate alloc;
 
-use wasmtime_environ::prelude;
+pub(crate) mod prelude {
+    pub use crate::{Error, Result};
+    pub use anyhow::{anyhow, bail, ensure, format_err, Context};
+    pub use wasmtime_environ::prelude::*;
+}
 
 /// A helper macro to safely map `MaybeUninit<T>` to `MaybeUninit<U>` where `U`
 /// is a field projection within `T`.
@@ -375,6 +379,7 @@ use sync_nostd as sync;
 ///
 /// This type can be used to interact with `wasmtimes`'s extensive use
 /// of `anyhow::Error` while still not directly depending on `anyhow`.
+///
 /// This type alias is identical to `anyhow::Result`.
 #[doc(no_inline)]
 pub use anyhow::{Error, Result};

crates/wasmtime/src/profiling_agent.rs

@@ -1,6 +1,4 @@
 use crate::prelude::*;
-#[allow(unused)]
-use anyhow::{bail, Result};
 
 cfg_if::cfg_if! {
     if #[cfg(all(feature = "profiling", target_os = "linux"))] {

crates/wasmtime/src/profiling_agent/jitdump.rs

@@ -13,14 +13,12 @@
 
 use crate::prelude::*;
 use crate::profiling_agent::ProfilingAgent;
-use anyhow::Result;
+use object::elf;
 use std::process;
 use std::sync::Mutex;
 use target_lexicon::Architecture;
 use wasmtime_jit_debug::perf_jitdump::*;
 
-use object::elf;
-
 /// Interface for driving the creation of jitdump files
 struct JitDumpAgent {
     pid: u32,

crates/wasmtime/src/profiling_agent/perfmap.rs

@@ -1,6 +1,5 @@
 use crate::prelude::*;
 use crate::profiling_agent::ProfilingAgent;
-use anyhow::Result;
 use std::io::{self, BufWriter, Write};
 use std::process;
 use std::{fs::File, sync::Mutex};