feat(tvix/nix-compat): add drvfmt

This small tool formats A-Term in a more readable format. It's a lossy
conversion for non-valid UTF-8 environment values.

Change-Id: I65a51054d7faf528321bc2d9fc4425180a7813f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9970
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
This commit is contained in:
Florian Klink 2023-11-06 11:43:34 +02:00 committed by flokli
parent 14849829fd
commit 9f5b1213f9
2 changed files with 48 additions and 0 deletions

View file

@ -4195,6 +4195,13 @@ rec {
crateName = "nix-compat";
version = "0.1.0";
edition = "2021";
crateBin = [
{
name = "drvfmt";
path = "src/bin/drvfmt.rs";
requiredFeatures = [ ];
}
];
# We can't filter paths with references in Nix 2.4
# See https://github.com/NixOS/nix/issues/5410
src =

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@ -0,0 +1,41 @@
use std::{collections::BTreeMap, io::Read};
use nix_compat::derivation::Derivation;
use serde_json::json;
/// construct a serde_json::Value from a Derivation.
/// Some environment values can be non-valid UTF-8 strings.
/// `serde_json` prints them out really unreadable.
/// This is a tool to print A-Terms in a more readable fashion, so we brutally
/// use [BString::to_string] to get a UTF-8 string (replacing invalid characters
/// with the Unicode replacement codepoint).
fn build_serde_json_value(drv: Derivation) -> serde_json::Value {
json!({
"args": drv.arguments,
"builder": drv.builder,
"env": drv.environment.into_iter().map(|(k,v)| (k, v.to_string())).collect::<BTreeMap<String, String>>(),
"inputDrvs": drv.input_derivations,
"inputSrcs": drv.input_sources,
"outputs": drv.outputs,
"system": drv.system,
})
}
fn main() {
// read A-Term from stdin
let mut buf = Vec::new();
std::io::stdin()
.read_to_end(&mut buf)
.expect("failed to read from stdin");
match Derivation::from_aterm_bytes(&buf) {
Ok(drv) => {
println!(
"{}",
serde_json::to_string_pretty(&build_serde_json_value(drv))
.expect("unable to serialize")
);
}
Err(e) => eprintln!("unable to parse derivation: {:#?}", e),
}
}