wado-host

The native host pieces that wado-cli, wado-dev-tools, the runners, and wado-compiler-tests share.

Rules

• This crate exists so that the compiler's tests never depend on wado-cli. It depends on the compiler, so nothing here may be needed by the compiler library itself.
• The toolchain feature, on by default, gates what needs the compiler. A runner turns it off, so everything a guest reaches and the command line of a run stay free of it.
• It is native-only. Code the browser also runs belongs in wado-lsp, which must build for wasm32-unknown-unknown.
• Put a piece here once a second crate needs it, not before. What only wado needs stays in wado-cli.

Module Map

• timezone.rs — the host for wasi:clocks/timezone, which wasmtime binds but does not implement.
• stub_host.rs — StubHost, wado-lsp's FilesystemCompilerHost with the dependency index and environment answered from HostStubs. It compiles the e2e fixtures for both the tests and the golden dumps.
• fixture.rs — CompileInputs, the __DATA__ keys that say how to compile a fixture. The e2e harness and the golden dumps both read them, so a golden records the program its test runs.
• kiln/ — the Kiln pipeline (driver.rs), the generator runtime (runtime.rs), the compiled-component cache (component_cache.rs), and the per-invocation cache state (metadata.rs). wado feeds the pipeline its own generator provider; local.rs feeds it the generators a fixture names, each compiled after its own invocations have run.
• random.rs — the fixed-seed wasi:random/insecure and insecure-seed that a Kiln generator, a core:eval program and a test get, so each stays a function of its input.
• sync.rs — how production code locks a mutex and joins a task or thread. A poisoned guard is recovered, and test mocks may still unwrap. A panic in a joined task continues in the caller, and one in a thread nobody joins ends the process.
• sandbox.rs — spawning a child confined to the guest's grants plus a fixed baseline, for core:process: Landlock and seccomp in sandbox/linux.rs, sandbox-exec in sandbox/macos.rs, and the terminal a child holds as a shell's job does in sandbox/terminal.rs. See WEP: core:process.
• process_host.rs — the core:process host: whether a guest may spawn, and the streams and kill of each child. sandbox.rs confines it.
• http_hooks.rs — the wasi:http client's connections, on the trust store of tls_trust.rs.
• user_config.rs — the user's ~/.config/wado/config.toml ($XDG_CONFIG_HOME): the Wado root and [process] read. Read once, and ignored whole when another user could have written it.
• path_search.rs — finding a program on PATH, for wado <name>, core:process, and a runner started without WADO.
• ticker.rs — Ticker, a thread on an interval that dropping stops and joins.
• engine.rs — the Wasm features and GC defaults every wasmtime engine takes, so the e2e harness runs a program as wado does, and the fuel-metered engine generators and core:eval run on.
• options.rs — every option wado and the runners share, with the CliExit a command ends in. wado-cli applies a compile knob to the compiler's types; a runner passes it on as spelled.
• guest.rs — what a guest reaches, on every host: the store data, the linker and the engine under the runtime knobs. A host embeds a GuestState and names the field to guest_views!.
• runner.rs — what wado run and each wado run-* subcommand share, so a program behaves the same under all of them: the command line, the compile (wado build -o -), the run and the guest profile.
• gc_log.rs — --gc-log, read off wasmtime's trace log, the only place it reports a collection.
• fuel.rs — the price of each Wasm operator in fuel, which every metered engine takes. See WEP: Fuel Benchmarks.