Clarify how "ensure" queries check whether they can skip execution#153033
Merged
rust-bors[bot] merged 1 commit intorust-lang:mainfrom Feb 24, 2026
Merged
Clarify how "ensure" queries check whether they can skip execution#153033rust-bors[bot] merged 1 commit intorust-lang:mainfrom
rust-bors[bot] merged 1 commit intorust-lang:mainfrom
Conversation
rustbot
added
A-query-system
nnethercote
approved these changes
Feb 24, 2026
Contributor
|
Nice clarifications. @bors r+ rollup |
Contributor
rust-bors
bot
added
S-waiting-on-bors
JonathanBrouwer
added a commit
to JonathanBrouwer/rust
that referenced
this pull request
Feb 24, 2026
Clarify how "ensure" queries check whether they can skip execution The current `check_cache: bool` field in QueryMode is confusing for a few reasons: - It actually refers to checking the *disk cache*, not the in-memory cache. - It gives no indication of what condition is being checked, or why. - It obscures the link between `tcx.ensure_ok()` and `tcx.ensure_done()`, and the actual check. This PR replaces that field with an `EnsureMode` enum that distinguishes between ensure-ok and ensure-done, and leaves the actual check as an implementation detail of the ensure-done mode. This PR also renames `ensure_must_run` → `check_if_ensure_can_skip_execution`, and uses a return struct to more clearly indicate how this helper function gives permission for its caller to skip execution of a query that would otherwise be executed. This also inverts the sense of the returned boolean, which was previously “must run” but is now ”skip execution”. r? nnethercote (or compiler)
JonathanBrouwer
added a commit
to JonathanBrouwer/rust
that referenced
this pull request
Feb 24, 2026
Clarify how "ensure" queries check whether they can skip execution The current `check_cache: bool` field in QueryMode is confusing for a few reasons: - It actually refers to checking the *disk cache*, not the in-memory cache. - It gives no indication of what condition is being checked, or why. - It obscures the link between `tcx.ensure_ok()` and `tcx.ensure_done()`, and the actual check. This PR replaces that field with an `EnsureMode` enum that distinguishes between ensure-ok and ensure-done, and leaves the actual check as an implementation detail of the ensure-done mode. This PR also renames `ensure_must_run` → `check_if_ensure_can_skip_execution`, and uses a return struct to more clearly indicate how this helper function gives permission for its caller to skip execution of a query that would otherwise be executed. This also inverts the sense of the returned boolean, which was previously “must run” but is now ”skip execution”. r? nnethercote (or compiler)
This was referenced Feb 24, 2026
rust-bors bot
pushed a commit
that referenced
this pull request
Feb 24, 2026
…uwer Rollup of 15 pull requests Successful merges: - #152176 (Neon fast path for str::contains) - #152657 (std: move `exit` out of PAL) - #152841 (Streamline `QueryVTableUnerased` into `GetQueryVTable`) - #152845 (Skip `tidy` in PR CI jobs not dedicated to running `tidy`) - #152897 (Add optional json logging) - #153009 (Remove `rustc_feedable_queries` and `define_feedable` macros.) - #151558 (Port diagnostic attributes) - #152492 (mGCA: Enforce WF element types for array valtrees) - #152888 (Fix async drop glue MIR bug) - #152988 (Port `#[register_tool]` to the new attribute system) - #153018 (`unused_must_use` lint improvements) - #153023 (Update books) - #153033 (Clarify how "ensure" queries check whether they can skip execution) - #153043 (fix error on missing value for -C flags) - #153045 (rustc-dev-guide subtree update) Failed merges: - #153032 (Fix attribute parser and kind names.)
rust-timer
added a commit
that referenced
this pull request
Feb 24, 2026
Rollup merge of #153033 - Zalathar:ensure, r=nnethercote Clarify how "ensure" queries check whether they can skip execution The current `check_cache: bool` field in QueryMode is confusing for a few reasons: - It actually refers to checking the *disk cache*, not the in-memory cache. - It gives no indication of what condition is being checked, or why. - It obscures the link between `tcx.ensure_ok()` and `tcx.ensure_done()`, and the actual check. This PR replaces that field with an `EnsureMode` enum that distinguishes between ensure-ok and ensure-done, and leaves the actual check as an implementation detail of the ensure-done mode. This PR also renames `ensure_must_run` → `check_if_ensure_can_skip_execution`, and uses a return struct to more clearly indicate how this helper function gives permission for its caller to skip execution of a query that would otherwise be executed. This also inverts the sense of the returned boolean, which was previously “must run” but is now ”skip execution”. r? nnethercote (or compiler)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The current
check_cache: boolfield in QueryMode is confusing for a few reasons:tcx.ensure_ok()andtcx.ensure_done(), and the actual check.This PR replaces that field with an
EnsureModeenum that distinguishes between ensure-ok and ensure-done, and leaves the actual check as an implementation detail of the ensure-done mode.This PR also renames
ensure_must_run→check_if_ensure_can_skip_execution, and uses a return struct to more clearly indicate how this helper function gives permission for its caller to skip execution of a query that would otherwise be executed. This also inverts the sense of the returned boolean, which was previously “must run” but is now ”skip execution”.r? nnethercote (or compiler)