From 4dca459e86b85a87e1c5d19c97b8936c842bab05 Mon Sep 17 00:00:00 2001 From: Michael Woerister Date: Fri, 6 Jan 2017 10:51:37 -0500 Subject: [PATCH] trans: Disambiguate generic instance symbol names by instantiating crate. Two crates will often instantiate the same generic functions. Since we don't make any attempt to re-use these instances cross-crate, we would run into symbol conflicts for anything with external linkage. In order to avoid this, this commit makes the compiler incorporate the ID of the instantiating crate into the symbol hash. This way equal generic instances will have different symbols names when used in different crates. --- src/librustc_trans/back/symbol_names.rs | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/librustc_trans/back/symbol_names.rs b/src/librustc_trans/back/symbol_names.rs index 938848054fe..8f8c48a06b2 100644 --- a/src/librustc_trans/back/symbol_names.rs +++ b/src/librustc_trans/back/symbol_names.rs @@ -152,6 +152,15 @@ fn get_symbol_hash<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, assert!(!substs.has_erasable_regions()); assert!(!substs.needs_subst()); substs.visit_with(&mut hasher); + + // If this is an instance of a generic function, we also hash in + // the ID of the instantiating crate. This avoids symbol conflicts + // in case the same instances is emitted in two crates of the same + // project. + if substs.types().next().is_some() { + hasher.hash(scx.tcx().crate_name.as_str()); + hasher.hash(scx.sess().local_crate_disambiguator().as_str()); + } } }); -- 2.44.0