bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Auto merge of #100748 - SparrowLii:query_depth, r=cjgillot

Browse source 
add `depth_limit` in `QueryVTable` to avoid entering a new tcx in `layout_of`

Fixes #49735
Updates #48685

The `layout_of` query needs to check whether it overflows the depth limit, and the current implementation needs to create a new `ImplicitCtxt` inside `layout_of`. However, `start_query` will already create a new `ImplicitCtxt`, so we can check the depth limit in `start_query`.

We can tell whether we need to check the depth limit simply by whether the return value of `to_debug_str` of the query is `layout_of`. But I think adding the `depth_limit` field in `QueryVTable` may be more elegant and more scalable.
This commit is contained in:
bors 2022-08-25 21:27:38 +00:00
commit cfb5ae26a4
8 changed files with 82 additions and 53 deletions
Download patch file Download diff file Expand all files Collapse all files

20
compiler/rustc_query_impl/src/plumbing.rs
View file

@ -96,6 +96,7 @@ impl QueryContext for QueryCtxt<'_> {
fn start_query<R>(
&self,
token: QueryJobId,
depth_limit: bool,
diagnostics: Option<&Lock<ThinVec<Diagnostic>>>,
compute: impl FnOnce() -> R,
) -> R {
@ -103,12 +104,16 @@ impl QueryContext for QueryCtxt<'_> {
// as `self`, so we use `with_related_context` to relate the 'tcx lifetimes
// when accessing the `ImplicitCtxt`.
tls::with_related_context(**self, move |current_icx| {
if depth_limit && !self.recursion_limit().value_within_limit(current_icx.query_depth) {
self.depth_limit_error();
}
// Update the `ImplicitCtxt` to point to our new query job.
let new_icx = ImplicitCtxt {
tcx: **self,
query: Some(token),
diagnostics,
layout_depth: current_icx.layout_depth,
query_depth: current_icx.query_depth + depth_limit as usize,
task_deps: current_icx.task_deps,
};
@ -210,6 +215,18 @@ macro_rules! is_eval_always {
};
}
macro_rules! depth_limit {
([]) => {{
false
}};
([(depth_limit) $($rest:tt)*]) => {{
true
}};
([$other:tt $($modifiers:tt)*]) => {
depth_limit!([$($modifiers)*])
};
}
macro_rules! hash_result {
([]) => {{
Some(dep_graph::hash_result)
@ -349,6 +366,7 @@ macro_rules! define_queries {
QueryVTable {
anon: is_anon!([$($modifiers)*]),
eval_always: is_eval_always!([$($modifiers)*]),
depth_limit: depth_limit!([$($modifiers)*]),
dep_kind: dep_graph::DepKind::$name,
hash_result: hash_result!([$($modifiers)*]),
handle_cycle_error: |tcx, mut error| handle_cycle_error!([$($modifiers)*][tcx, error]),