diff options
| -rw-r--r-- | compiler/rustc_middle/src/ty/print/pretty.rs | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index a2211f4c3b2..f8a476266d6 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -2408,7 +2408,7 @@ fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, N /// /// The implementation uses similar import discovery logic to that of 'use' suggestions. fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> { - let mut map = FxHashMap::default(); + let mut map: FxHashMap<DefId, Symbol> = FxHashMap::default(); if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths { // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths` @@ -2446,8 +2446,29 @@ fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> FxHashMap<DefId, Symbol> { }); for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() { + use std::collections::hash_map::Entry::{Occupied, Vacant}; + if let Some(def_id) = opt_def_id { - map.insert(def_id, symbol); + match map.entry(def_id) { + Occupied(mut v) => { + // A single DefId can be known under multiple names (e.g., + // with a `pub use ... as ...;`). We need to ensure that the + // name placed in this map is chosen deterministically, so + // if we find multiple names (`symbol`) resolving to the + // same `def_id`, we prefer the lexicographically smallest + // name. + // + // Any stable ordering would be fine here though. + if *v.get() != symbol { + if v.get().as_str() > symbol.as_str() { + v.insert(symbol); + } + } + } + Vacant(v) => { + v.insert(symbol); + } + } } } |