maurice/snix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

fix(tvix/eval): fix b/281 by adding Value::Catchable

Browse source 
This commit makes catchable errors a variant of Value.

The main downside of this approach is that we lose the ability to
use Rust's `?` syntax for propagating catchable errors.

Change-Id: Ibe89438d8a70dcec29e016df692b5bf88a5cad13
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9289
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
This commit is contained in:
Adam Joseph 2023-09-09 22:02:56 -07:00 • committed by clbot
parent 926459ce69
commit 05f42519b5
16 changed files with 320 additions and 247 deletions
Download patch file Download diff file Expand all files Collapse all files

57
tvix/eval/src/builtins/impure.rs
View file

@ -27,40 +27,47 @@ mod impure_builtins {
#[builtin("pathExists")]
async fn builtin_path_exists(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
let path = coerce_value_to_path(&co, path).await?;
Ok(generators::request_path_exists(&co, path).await)
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::Catchable(cek)),
Ok(path) => Ok(generators::request_path_exists(&co, path).await),
}
}
#[builtin("readDir")]
async fn builtin_read_dir(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
let path = coerce_value_to_path(&co, path).await?;
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::Catchable(cek)),
Ok(path) => {
let dir = generators::request_read_dir(&co, path).await;
let res = dir.into_iter().map(|(name, ftype)| {
(
// TODO: propagate Vec<u8> or bytes::Bytes into NixString.
NixString::from(
String::from_utf8(name.to_vec()).expect("parsing file name as string"),
),
Value::String(
match ftype {
FileType::Directory => "directory",
FileType::Regular => "regular",
FileType::Symlink => "symlink",
FileType::Unknown => "unknown",
}
.into(),
),
)
});
let dir = generators::request_read_dir(&co, path).await;
let res = dir.into_iter().map(|(name, ftype)| {
(
// TODO: propagate Vec<u8> or bytes::Bytes into NixString.
NixString::from(
String::from_utf8(name.to_vec()).expect("parsing file name as string"),
),
Value::String(
match ftype {
FileType::Directory => "directory",
FileType::Regular => "regular",
FileType::Symlink => "symlink",
FileType::Unknown => "unknown",
}
.into(),
),
)
});
Ok(Value::attrs(NixAttrs::from_iter(res)))
Ok(Value::attrs(NixAttrs::from_iter(res)))
}
}
}
#[builtin("readFile")]
async fn builtin_read_file(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
let path = coerce_value_to_path(&co, path).await?;
Ok(generators::request_read_to_string(&co, path).await)
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::Catchable(cek)),
Ok(path) => Ok(generators::request_read_to_string(&co, path).await),
}
}
}

57
tvix/eval/src/builtins/mod.rs
View file

@ -40,18 +40,25 @@ pub const CURRENT_PLATFORM: &str = env!("TVIX_CURRENT_SYSTEM");
/// builtin. This coercion can _never_ be performed in a Nix program
/// without using builtins (i.e. the trick `path: /. + path` to
/// convert from a string to a path wouldn't hit this code).
pub async fn coerce_value_to_path(co: &GenCo, v: Value) -> Result<PathBuf, ErrorKind> {
pub async fn coerce_value_to_path(
co: &GenCo,
v: Value,
) -> Result<Result<PathBuf, CatchableErrorKind>, ErrorKind> {
let value = generators::request_force(co, v).await;
if let Value::Path(p) = value {
return Ok(*p);
return Ok(Ok(*p));
}
let vs = generators::request_string_coerce(co, value, CoercionKind::Weak).await;
let path = PathBuf::from(vs.as_str());
if path.is_absolute() {
Ok(path)
} else {
Err(ErrorKind::NotAnAbsolutePath(path))
match generators::request_string_coerce(co, value, CoercionKind::Weak).await {
Ok(vs) => {
let path = PathBuf::from(vs.as_str());
if path.is_absolute() {
Ok(Ok(path))
} else {
Err(ErrorKind::NotAnAbsolutePath(path))
}
}
Err(cek) => Ok(Err(cek)),
}
}
@ -218,8 +225,10 @@ mod pure_builtins {
if i != 0 {
res.push_str(&separator);
}
let s = generators::request_string_coerce(&co, val, CoercionKind::Weak).await;
res.push_str(s.as_str());
match generators::request_string_coerce(&co, val, CoercionKind::Weak).await {
Ok(s) => res.push_str(s.as_str()),
Err(c) => return Ok(Value::Catchable(c)),
}
}
Ok(res.into())
}
@ -313,6 +322,9 @@ mod pure_builtins {
// and our tests for foldl'.
nul = generators::request_call_with(&co, op.clone(), [nul, val]).await;
nul = generators::request_force(&co, nul).await;
if let c @ Value::Catchable(_) = nul {
return Ok(c);
}
}
Ok(nul)
@ -340,9 +352,13 @@ mod pure_builtins {
#[builtin("toJSON")]
async fn builtin_to_json(co: GenCo, val: Value) -> Result<Value, ErrorKind> {
let json_value = val.to_json(&co).await?;
let json_str = serde_json::to_string(&json_value)?;
Ok(json_str.into())
match val.to_json(&co).await? {
Err(cek) => Ok(Value::Catchable(cek)),
Ok(json_value) => {
let json_str = serde_json::to_string(&json_value)?;
Ok(json_str.into())
}
}
}
#[builtin("fromTOML")]
@ -893,7 +909,7 @@ mod pure_builtins {
#[builtin("throw")]
async fn builtin_throw(co: GenCo, message: Value) -> Result<Value, ErrorKind> {
Err(ErrorKind::CatchableErrorKind(CatchableErrorKind::Throw(
Ok(Value::Catchable(CatchableErrorKind::Throw(
message.to_str()?.to_string(),
)))
}
@ -929,15 +945,20 @@ mod pure_builtins {
#[builtin("toPath")]
async fn builtin_to_path(co: GenCo, s: Value) -> Result<Value, ErrorKind> {
let path: Value = crate::value::canon_path(coerce_value_to_path(&co, s).await?).into();
Ok(path.coerce_to_string(co, CoercionKind::Weak).await?)
match coerce_value_to_path(&co, s).await? {
Err(cek) => return Ok(Value::Catchable(cek)),
Ok(path) => {
let path: Value = crate::value::canon_path(path).into();
Ok(path.coerce_to_string(co, CoercionKind::Weak).await?)
}
}
}
#[builtin("tryEval")]
async fn builtin_try_eval(co: GenCo, #[lazy] e: Value) -> Result<Value, ErrorKind> {
let res = match generators::request_try_force(&co, e).await {
Some(value) => [("value", value), ("success", true.into())],
None => [("value", false.into()), ("success", false.into())],
Value::Catchable(_) => [("value", false.into()), ("success", false.into())],
value => [("value", value), ("success", true.into())],
};
Ok(Value::attrs(NixAttrs::from_iter(res.into_iter())))

4
tvix/eval/src/builtins/to_xml.rs
View file

@ -134,6 +134,10 @@ fn value_variant_to_xml<W: Write>(w: &mut EventWriter<W>, value: &Value) -> Resu
metadata: Some(Rc::new(value.clone())),
})
}
Value::Catchable(_) => {
panic!("tvix bug: value_to_xml() called on a value which had not been deep-forced")
}
}?;
Ok(())