wasm-smith: Deduplicate and devirtualize configuration (#1351)

* wasm-smith: Deduplicate and devirtualize configuration

This makes it so that we don't have three or four places where each config
option needs to be enumerated anymore and also removes the `Config` trait and
replaces it with a `Config` struct (what used to be the `SwarmConfig`
struct). This struct implements `Arbitrary` and therefore you can still do swarm
testing by generating an arbitrary config and then using that to generate a
module. There is also no difference between `Module` and `ConfiguredModule`
anymore.

Overall, I feel like this is a big clean up, and also should in theory make
module generation a little faster since there won't be so many indirect calls.

* Fix some compile errors

* Fix fuzz target compilation

* Fix some warnings and errors in the doc build

* Fix more fuzz target compilation errors

crates/c-api/src/lib.rs

@@ -7,7 +7,7 @@
 #![allow(non_snake_case, non_camel_case_types, non_upper_case_globals)]
 
 use arbitrary::{Error, Unstructured};
-use wasm_smith::{DefaultConfig, Module};
+use wasm_smith::{Config, Module};
 
 #[repr(C)]
 pub struct wasm_tools_byte_vec_t {
@@ -50,7 +50,7 @@ pub unsafe extern "C" fn wasm_smith_create(
 
     bytes.data = std::ptr::null_mut();
     let mut u = Unstructured::new(seed_bytes);
-    match Module::new(DefaultConfig::default(), &mut u) {
+    match Module::new(Config::default(), &mut u) {
         Ok(module) => {
             let mut wasm_buffer = module.to_bytes().into_boxed_slice();
             bytes.data = wasm_buffer.as_mut_ptr();

crates/fuzz-stats/src/bin/failed-instantiations.rs

@@ -2,7 +2,6 @@ use arbitrary::{Arbitrary, Error, Unstructured};
 use rand::RngCore;
 use std::sync::atomic::{AtomicIsize, AtomicUsize, Ordering::SeqCst};
 use std::sync::Arc;
-use wasm_smith::SwarmConfig;
 use wasmtime::*;
 
 struct State {
@@ -95,12 +94,12 @@ impl State {
     /// Records when instantiation fails and why it fails.
     fn run_once(&self, data: &[u8]) -> Result<(), Error> {
         let mut u = Unstructured::new(data);
-        // Here `SwarmConfig` is used to get hopefully a bit more coverage of
+        // Here swarm testing is used to get hopefully a bit more coverage of
         // interesting states, and we also forcibly disable all `start`
         // functions for now. Not much work has gone into minimizing the traps
         // generated from wasm functions themselves, and this shouldn't be
         // enabled until that's been worked on.
-        let mut config = SwarmConfig::arbitrary(&mut u)?;
+        let mut config = wasm_smith::Config::arbitrary(&mut u)?;
         config.allow_start_export = false;
 
         // Wasmtime doesn't support this proposal yet.

crates/wasm-shrink/src/lib.rs

@@ -1,7 +1,7 @@
 //! Shrink a Wasm file while maintaining a property of interest (such as
 //! triggering a compiler bug).
 //!
-//! See the [`WasmShrink`][WasmShrink] type for details.
+//! See the [`WasmShrink`] type for details.
 
 use std::collections::HashSet;
 

crates/wasm-smith/Cargo.toml

@@ -16,14 +16,17 @@ name = "corpus"
 harness = false
 
 [dependencies]
+anyhow = { workspace = true, optional = true }
 arbitrary = { workspace = true, features = ["derive"] }
+clap = { workspace = true, optional = true }
 flagset = "0.4"
 indexmap = { workspace = true }
 leb128 = { workspace = true }
 serde = { workspace = true, optional = true }
 serde_derive = { workspace = true, optional = true }
 wasm-encoder = { workspace = true, features = ['wasmparser'] }
 wasmparser = { workspace = true, optional = true }
+wat = { workspace = true, optional = true }
 
 [dev-dependencies]
 criterion = { workspace = true }
@@ -36,4 +39,4 @@ wat = { path = "../wat" }
 libfuzzer-sys = { workspace = true }
 
 [features]
-_internal_cli = ["serde", "serde_derive", "wasmparser"]
+_internal_cli = ["anyhow", "clap", "flagset/serde", "serde", "serde_derive", "wasmparser", "wat"]