Make compiler deterministic: use BTreeMap for property_analysis#11219
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ogoffart merged 1 commit intoslint-ui:masterfrom Apr 2, 2026
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since visited is not iterated, i don't really understand where the non-determinism comes from.
Replace `HashMap<SmolStr, PropertyAnalysis>` with `BTreeMap` in `Element::property_analysis` to ensure deterministic iteration order. The HashMap was iterated in several passes (inlining, move_declarations, optimize_useless_rectangles, resolve_native_classes), and since HashMap uses Rust's default RandomState hasher, the iteration order varied between runs. This non-determinism propagated through the compiler, causing binding loop diagnostics to be emitted at different source positions across runs/platforms. Also updates namedreference.rs to use btree_map::Entry instead of hash_map::Entry, and move_declarations.rs to use BTreeMap for the local property_analysis collections.
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Now that slint-ui#11219 (BTreeMap for property_analysis) is merged, the compiler's analysis order is deterministic. Restore the three syntax tests that were removed due to platform-dependent diagnostic positions: - binding_loop_issue_7849.slint (regression test for slint-ui#7849) - binding_loop_nested_repeater.slint - binding_loop_root_changed_callback.slint Also update loop descriptions in binding_loop_if_condition.slint and binding_loop_init_callback.slint to reflect the new deterministic traversal order which now includes the current property as the loop starting point.
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Summary
HashMap<SmolStr, PropertyAnalysis>withBTreeMapinElement::property_analysisto ensure deterministic iteration ordernamedreference.rsto usebtree_map::Entryinstead ofhash_map::Entrymove_declarations.rsto useBTreeMapfor local property analysis collectionsThe
HashMapwas iterated in several passes (inlining,move_declarations,optimize_useless_rectangles,resolve_native_classes). SinceHashMapuses Rust's defaultRandomStatehasher, iteration order varied between runs, which is a source of non-determinism in the compiler.This is a standalone improvement — a deterministic compiler is desirable regardless. It may or may not be sufficient to resolve the cross-platform diagnostic position differences seen in #10552; that would need to be validated by merging this and re-running CI on that branch.
Related: #11188
Test plan
cargo check -p slint-compilerpasses