From ea7d63e177d8a951e30bc00918081eb069e2efb2 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Tue, 13 Dec 2022 20:17:00 +0300 Subject: [PATCH] feat(tvix/cli): implement `NixCompatIO` helper type This type allows for temporarily compatibility with the C++ Nix store, specifically (for now) it gives us the store directory used by Nix and imports files the same way. Change-Id: I4767794ef2863eba49661315c63c4e17de946d60 Reviewed-on: https://cl.tvl.fyi/c/depot/+/7587 Reviewed-by: grfn Tested-by: BuildkiteCI --- tvix/Cargo.lock | 1 + tvix/Cargo.nix | 4 ++ tvix/cli/Cargo.toml | 1 + tvix/cli/src/main.rs | 4 +- tvix/cli/src/nix_compat.rs | 82 ++++++++++++++++++++++++++++++++++++++ tvix/eval/src/lib.rs | 2 +- 6 files changed, 92 insertions(+), 2 deletions(-) create mode 100644 tvix/cli/src/nix_compat.rs diff --git a/tvix/Cargo.lock b/tvix/Cargo.lock index b6815b245..6724b3d58 100644 --- a/tvix/Cargo.lock +++ b/tvix/Cargo.lock @@ -1493,6 +1493,7 @@ dependencies = [ "clap 4.0.27", "dirs", "rustyline", + "smol_str", "tvix-eval", ] diff --git a/tvix/Cargo.nix b/tvix/Cargo.nix index 1447c4ea1..cce3bbca8 100644 --- a/tvix/Cargo.nix +++ b/tvix/Cargo.nix @@ -4229,6 +4229,10 @@ rec { name = "rustyline"; packageId = "rustyline"; } + { + name = "smol_str"; + packageId = "smol_str"; + } { name = "tvix-eval"; packageId = "tvix-eval"; diff --git a/tvix/cli/Cargo.toml b/tvix/cli/Cargo.toml index ae7cd2221..099002353 100644 --- a/tvix/cli/Cargo.toml +++ b/tvix/cli/Cargo.toml @@ -12,3 +12,4 @@ tvix-eval = { path = "../eval" } rustyline = "10.0.0" clap = { version = "4.0", features = ["derive", "env"] } dirs = "4.0.0" +smol_str = "0.1" diff --git a/tvix/cli/src/main.rs b/tvix/cli/src/main.rs index 7e6b7520b..3228489e7 100644 --- a/tvix/cli/src/main.rs +++ b/tvix/cli/src/main.rs @@ -1,3 +1,5 @@ +mod nix_compat; + use std::{fs, path::PathBuf}; use clap::Parser; @@ -39,7 +41,7 @@ struct Args { /// evaluation succeeded. fn interpret(code: &str, path: Option, args: &Args) -> bool { let mut eval = tvix_eval::Evaluation::new(code, path); - eval.io_handle = Box::new(tvix_eval::StdIO); + eval.io_handle = Box::new(nix_compat::NixCompatIO::new()); eval.nix_path = args.nix_search_path.clone(); let source_map = eval.source_map(); diff --git a/tvix/cli/src/nix_compat.rs b/tvix/cli/src/nix_compat.rs new file mode 100644 index 000000000..75281d90e --- /dev/null +++ b/tvix/cli/src/nix_compat.rs @@ -0,0 +1,82 @@ +//! This module implements (temporary) compatibility shims between +//! Tvix and C++ Nix. +//! +//! These are not intended to be long-lived, but should bootstrap Tvix +//! by piggybacking off functionality that already exists in Nix and +//! is still being implemented in Tvix. + +use std::path::Path; +use std::process::Command; +use std::{io, path::PathBuf}; + +use smol_str::SmolStr; +use tvix_eval::{ErrorKind, EvalIO, FileType, StdIO}; + +/// Compatibility implementation of [`EvalIO`] that uses C++ Nix to +/// write files to the Nix store. +pub struct NixCompatIO { + /// Most IO requests are tunneled through to [`tvix_eval::StdIO`] + /// instead. + underlying: StdIO, +} + +impl NixCompatIO { + pub fn new() -> Self { + NixCompatIO { underlying: StdIO } + } +} + +impl EvalIO for NixCompatIO { + fn store_dir(&self) -> Option { + Some("/nix/store".into()) + } + + // Pass path imports through to `nix-store --add` + fn import_path(&self, path: &Path) -> Result { + add_to_store(path).map_err(|error| ErrorKind::IO { + error: std::rc::Rc::new(error), + path: Some(path.to_path_buf()), + }) + } + + // Pass the rest of the functions through to `Self::underlying` + fn path_exists(&self, path: PathBuf) -> Result { + self.underlying.path_exists(path) + } + + fn read_to_string(&self, path: PathBuf) -> Result { + self.underlying.read_to_string(path) + } + + fn read_dir(&self, path: PathBuf) -> Result, ErrorKind> { + self.underlying.read_dir(path) + } +} + +/// Add a path to the Nix store using the `nix-store --add` +/// functionality from C++ Nix. +fn add_to_store(path: &Path) -> Result { + if !path.try_exists()? { + return Err(io::Error::from(io::ErrorKind::NotFound)); + } + + let mut cmd = Command::new("nix-store"); + cmd.arg("--add"); + cmd.arg(path); + + let out = cmd.output()?; + + if !out.status.success() { + return Err(io::Error::new( + io::ErrorKind::Other, + String::from_utf8_lossy(&out.stderr), + )); + } + + let out_path_str = String::from_utf8(out.stdout) + .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?; + + let mut out_path = PathBuf::new(); + out_path.push(out_path_str.trim()); + Ok(out_path) +} diff --git a/tvix/eval/src/lib.rs b/tvix/eval/src/lib.rs index d8620a145..bf6c01426 100644 --- a/tvix/eval/src/lib.rs +++ b/tvix/eval/src/lib.rs @@ -45,7 +45,7 @@ use std::sync::Arc; pub use crate::builtins::global_builtins; pub use crate::compiler::{compile, prepare_globals}; pub use crate::errors::{Error, ErrorKind, EvalResult}; -pub use crate::io::{DummyIO, EvalIO}; +pub use crate::io::{DummyIO, EvalIO, FileType}; use crate::observer::{CompilerObserver, RuntimeObserver}; pub use crate::pretty_ast::pretty_print_expr; pub use crate::source::SourceCode;