winch: Adding support for integration tests (#5588)

* Adding in the foundations for Winch `filetests`

This commit adds two new crates into the Winch workspace:
`filetests` and `test-macros`. The intent is to mimic the
structure of Cranelift `filetests`, but in a simpler way.

* Updates to documentation

This commits adds a high level document to outline how to test Winch
through the `winch-tools` utility. It also updates some inline
documentation which gets propagated to the CLI.

* Updating test-macro to use a glob instead of only a flat directory

winch/src/main.rs

@@ -1,77 +1,21 @@
-//! Winch CLI tool, meant mostly for testing purposes.
-//!
-//! Reads Wasm in binary/text format and compiles them
-//! to any of the supported architectures using Winch.
+mod compile;
+mod filetests;
 
-use anyhow::{Context, Result};
+use anyhow::Result;
 use clap::Parser;
-use cranelift_codegen::settings;
-use std::{fs, path::PathBuf, str::FromStr};
-use target_lexicon::Triple;
-use wasmtime_environ::{
-    wasmparser::{types::Types, Parser as WasmParser, Validator},
-    DefinedFuncIndex, FunctionBodyData, Module, ModuleEnvironment, Tunables,
-};
-use winch_codegen::{lookup, TargetIsa};
 
-mod disasm;
-
-#[derive(Parser, Debug)]
-struct Options {
-    /// The input file.
-    input: PathBuf,
-
-    /// The target architecture.
-    #[clap(long = "target")]
-    target: String,
+/// Winch compilation and testing tool.
+#[derive(Parser)]
+enum Commands {
+    /// Compile a Wasm module to the specified target architecture.
+    Compile(compile::Options),
+    /// Run the filetests.
+    Test(filetests::Options),
 }
 
 fn main() -> Result<()> {
-    let opt = Options::from_args();
-    let bytes = fs::read(&opt.input)
-        .with_context(|| format!("Failed to read input file {}", opt.input.display()))?;
-    let bytes = wat::parse_bytes(&bytes)?;
-    let triple = Triple::from_str(&opt.target)?;
-    let shared_flags = settings::Flags::new(settings::builder());
-    let isa_builder = lookup(triple)?;
-    let isa = isa_builder.build(shared_flags)?;
-    let mut validator = Validator::new();
-    let parser = WasmParser::new(0);
-    let mut types = Default::default();
-    let tunables = Tunables::default();
-    let mut translation = ModuleEnvironment::new(&tunables, &mut validator, &mut types)
-        .translate(parser, &bytes)
-        .context("Failed to translate WebAssembly module")?;
-    let _ = types.finish();
-
-    let body_inputs = std::mem::take(&mut translation.function_body_inputs);
-    let module = &translation.module;
-    let types = translation.get_types();
-
-    body_inputs
-        .into_iter()
-        .try_for_each(|func| compile(&*isa, module, types, func))?;
-
-    Ok(())
-}
-
-fn compile(
-    isa: &dyn TargetIsa,
-    module: &Module,
-    types: &Types,
-    f: (DefinedFuncIndex, FunctionBodyData<'_>),
-) -> Result<()> {
-    let index = module.func_index(f.0);
-    let sig = types
-        .func_type_at(index.as_u32())
-        .expect(&format!("function type at index {:?}", index.as_u32()));
-    let FunctionBodyData { body, validator } = f.1;
-    let validator = validator.into_validator(Default::default());
-    let buffer = isa
-        .compile_function(&sig, &body, validator)
-        .expect("Couldn't compile function");
-
-    disasm::print(buffer.data(), isa)?;
-
-    Ok(())
+    match Commands::parse() {
+        Commands::Compile(c) => compile::run(&c),
+        Commands::Test(t) => filetests::run(&t),
+    }
 }