Auto merge of #68414 - michaelwoerister:share-drop-glue, r=alexcrichton

Also share drop-glue when compiling with -Zshare-generics (i.e. at opt-level=0)

This PR adds drop-glue to the set of monomorphizations that can be shared across crates via `-Zshare-generics`.

This version of the PR might have detrimental effects on performance as it makes lots of stuff dependent on a single query results (`upstream_monomorphizations_for(def_id_of_drop_in_place)`). That should be fixable but let's do a perf run first.

Potentially fixes issue https://github.com/rust-lang/rust/issues/64140. (cc @alexcrichton)
The changes here are related to @matthewjasper's https://github.com/rust-lang/rust/pull/67332 but should be mostly orthogonal.

r? @ghost

1 files changed, 5 insertions, 1 deletions

diff --git a/src/librustc_codegen_ssa/back/write.rs b/src/librustc_codegen_ssa/back/write.rs
index 049faff7c49..841827d15fe 100644
--- a/src/librustc_codegen_ssa/back/write.rs
+++ b/src/librustc_codegen_ssa/back/write.rs
@@ -2,7 +2,8 @@ use super::command::Command;
 use super::link::{self, get_linker, remove};
 use super::linker::LinkerInfo;
 use super::lto::{self, SerializedModule};
-use super::symbol_export::{symbol_name_for_instance_in_crate, ExportedSymbols};
+use super::symbol_export::symbol_name_for_instance_in_crate;
+
 use crate::{
     CachedModuleCodegen, CodegenResults, CompiledModule, CrateInfo, ModuleCodegen, ModuleKind,
     RLIB_BYTECODE_EXTENSION,
@@ -12,6 +13,7 @@ use crate::traits::*;
 use jobserver::{Acquired, Client};
 use rustc::dep_graph::{WorkProduct, WorkProductFileKind, WorkProductId};
 use rustc::middle::cstore::EncodedMetadata;
+use rustc::middle::exported_symbols::SymbolExportLevel;
 use rustc::session::config::{
     self, Lto, OutputFilenames, OutputType, Passes, Sanitizer, SwitchWithOptPath,
 };
@@ -205,6 +207,8 @@ impl<B: WriteBackendMethods> Clone for TargetMachineFactory<B> {
     }
 }
 
+pub type ExportedSymbols = FxHashMap<CrateNum, Arc<Vec<(String, SymbolExportLevel)>>>;
+
 /// Additional resources used by optimize_and_codegen (not module specific)
 #[derive(Clone)]
 pub struct CodegenContext<B: WriteBackendMethods> {