tvl-depot/nix/nint/nint.rs
sterni 318d10e608 chore(nint): move from //users/sterni to //nix
Since //web/bubblegum depends on nint, we need to move it to a non user
directory to conform with the policy established via cl/3434.
Note that this likely doesn't mean greater stability (which isn't
really implied in depot anyways), since I still would like to use a more
elaborate calling convention to allow for additional useful features.

Change-Id: I616f905d8df13e3363674aab69a797b0d39fdd79
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3506
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
2021-09-10 11:08:03 +00:00

110 lines
2.9 KiB
Rust

extern crate serde_json;
use serde_json::Value;
use std::ffi::OsString;
use std::os::unix::ffi::{OsStringExt, OsStrExt};
use std::io::{Error, ErrorKind, Write};
use std::process::Command;
fn render_nix_string(s: &OsString) -> OsString {
let mut rendered = Vec::new();
rendered.extend(b"\"");
for b in s.as_os_str().as_bytes() {
match char::from(*b) {
'\"' => rendered.extend(b"\\\""),
'\\' => rendered.extend(b"\\\\"),
'$' => rendered.extend(b"\\$"),
_ => rendered.push(*b),
}
}
rendered.extend(b"\"");
OsString::from_vec(rendered)
}
fn render_nix_list(arr: &[OsString]) -> OsString {
let mut rendered = Vec::new();
rendered.extend(b"[ ");
for el in arr {
rendered.extend(render_nix_string(el).as_os_str().as_bytes());
rendered.extend(b" ");
}
rendered.extend(b"]");
OsString::from_vec(rendered)
}
fn main() -> std::io::Result<()> {
let mut nix_args = Vec::new();
let mut args = std::env::args_os().into_iter();
let mut in_args = true;
let mut argv: Vec<OsString> = Vec::new();
// skip argv[0]
args.next();
loop {
let arg = match args.next() {
Some(a) => a,
None => break,
};
if !arg.to_str().map(|s| s.starts_with("-")).unwrap_or(false) {
in_args = false;
}
if in_args {
match(arg.to_str()) {
Some("--arg") | Some("--argstr") => {
nix_args.push(arg);
nix_args.push(args.next().unwrap());
nix_args.push(args.next().unwrap());
Ok(())
}
_ => Err(Error::new(ErrorKind::Other, "unknown argument")),
}?
} else {
argv.push(arg);
}
}
if argv.len() < 1 {
Err(Error::new(ErrorKind::Other, "missing argv"))
} else {
let cd = std::env::current_dir()?.into_os_string();
nix_args.push(OsString::from("--arg"));
nix_args.push(OsString::from("currentDir"));
nix_args.push(cd);
nix_args.push(OsString::from("--arg"));
nix_args.push(OsString::from("argv"));
nix_args.push(render_nix_list(&argv[..]));
nix_args.push(OsString::from("--eval"));
nix_args.push(OsString::from("--json"));
nix_args.push(argv[0].clone());
let run = Command::new("nix-instantiate")
.args(nix_args)
.output()?;
match serde_json::from_slice(&run.stdout[..]) {
Ok(Value::String(s)) => Ok(print!("{}", s)),
Ok(_) => Err(Error::new(ErrorKind::Other, "output must be a string")),
_ => {
std::io::stderr().write_all(&run.stderr[..]);
Err(Error::new(ErrorKind::Other, "internal nix error"))
},
}
}
}