Revert "Merge CrateDisambiguator into StableCrateId"

This reverts commit d0ec85d3fb6d322496cb8f4bc1c21e19f23284ad.

9 files changed, 40 insertions, 35 deletions

diff --git a/compiler/rustc_middle/src/dep_graph/dep_node.rs b/compiler/rustc_middle/src/dep_graph/dep_node.rs
index aa54d1ae7b9..8476929eaec 100644
--- a/compiler/rustc_middle/src/dep_graph/dep_node.rs
+++ b/compiler/rustc_middle/src/dep_graph/dep_node.rs
@@ -285,7 +285,7 @@ pub type DepNode = rustc_query_system::dep_graph::DepNode<DepKind>;
 // required that their size stay the same, but we don't want to change
 // it inadvertently. This assert just ensures we're aware of any change.
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
-static_assert_size!(DepNode, 17);
+static_assert_size!(DepNode, 18);
 
 #[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
 static_assert_size!(DepNode, 24);
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 07b39c97c49..20bbf9097f4 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -15,7 +15,6 @@ use rustc_hir::intravisit::Visitor;
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_hir::*;
 use rustc_index::vec::Idx;
-use rustc_span::def_id::StableCrateId;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, Ident, Symbol};
@@ -991,24 +990,25 @@ pub(super) fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
     upstream_crates.hash_stable(&mut hcx, &mut stable_hasher);
     source_file_names.hash_stable(&mut hcx, &mut stable_hasher);
     tcx.sess.opts.dep_tracking_hash(true).hash_stable(&mut hcx, &mut stable_hasher);
-    tcx.sess.local_stable_crate_id().hash_stable(&mut hcx, &mut stable_hasher);
+    tcx.sess.local_crate_disambiguator().to_fingerprint().hash_stable(&mut hcx, &mut stable_hasher);
     tcx.untracked_crate.non_exported_macro_attrs.hash_stable(&mut hcx, &mut stable_hasher);
 
     let crate_hash: Fingerprint = stable_hasher.finish();
     Svh::new(crate_hash.to_smaller_hash())
 }
 
-fn upstream_crates(cstore: &dyn CrateStore) -> Vec<(StableCrateId, Svh)> {
+fn upstream_crates(cstore: &dyn CrateStore) -> Vec<(Symbol, Fingerprint, Svh)> {
     let mut upstream_crates: Vec<_> = cstore
         .crates_untracked()
         .iter()
         .map(|&cnum| {
-            let stable_crate_id = cstore.stable_crate_id_untracked(cnum);
+            let name = cstore.crate_name_untracked(cnum);
+            let disambiguator = cstore.crate_disambiguator_untracked(cnum).to_fingerprint();
             let hash = cstore.crate_hash_untracked(cnum);
-            (stable_crate_id, hash)
+            (name, disambiguator, hash)
         })
         .collect();
-    upstream_crates.sort_unstable_by_key(|&(stable_crate_id, _)| stable_crate_id);
+    upstream_crates.sort_unstable_by_key(|&(name, dis, _)| (name.as_str(), dis));
     upstream_crates
 }
 
diff --git a/compiler/rustc_middle/src/middle/cstore.rs b/compiler/rustc_middle/src/middle/cstore.rs
index df578708931..f09449ab864 100644
--- a/compiler/rustc_middle/src/middle/cstore.rs
+++ b/compiler/rustc_middle/src/middle/cstore.rs
@@ -14,7 +14,7 @@ use rustc_hir::definitions::{DefKey, DefPath, DefPathHash};
 use rustc_macros::HashStable;
 use rustc_session::search_paths::PathKind;
 use rustc_session::utils::NativeLibKind;
-use rustc_session::StableCrateId;
+use rustc_session::CrateDisambiguator;
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 use rustc_target::spec::Target;
@@ -206,7 +206,7 @@ pub trait CrateStore {
 
     // "queries" used in resolve that aren't tracked for incremental compilation
     fn crate_name_untracked(&self, cnum: CrateNum) -> Symbol;
-    fn stable_crate_id_untracked(&self, cnum: CrateNum) -> StableCrateId;
+    fn crate_disambiguator_untracked(&self, cnum: CrateNum) -> CrateDisambiguator;
     fn crate_hash_untracked(&self, cnum: CrateNum) -> Svh;
 
     // This is basically a 1-based range of ints, which is a little
diff --git a/compiler/rustc_middle/src/middle/exported_symbols.rs b/compiler/rustc_middle/src/middle/exported_symbols.rs
index 5ea78e087f8..288dd039446 100644
--- a/compiler/rustc_middle/src/middle/exported_symbols.rs
+++ b/compiler/rustc_middle/src/middle/exported_symbols.rs
@@ -48,8 +48,8 @@ impl<'tcx> ExportedSymbol<'tcx> {
 
 pub fn metadata_symbol_name(tcx: TyCtxt<'_>) -> String {
     format!(
-        "rust_metadata_{}_{:08x}",
+        "rust_metadata_{}_{}",
         tcx.crate_name(LOCAL_CRATE),
-        tcx.sess.local_stable_crate_id().to_u64(),
+        tcx.crate_disambiguator(LOCAL_CRATE).to_fingerprint().to_hex()
     )
 }
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index c354cdd985b..74650f50a1c 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -490,18 +490,15 @@ impl CodegenUnitNameBuilder<'tcx> {
             // local crate's ID. Otherwise there can be collisions between CGUs
             // instantiating stuff for upstream crates.
             let local_crate_id = if cnum != LOCAL_CRATE {
-                let local_stable_crate_id = tcx.sess.local_stable_crate_id();
-                format!(
-                    "-in-{}.{:08x}",
-                    tcx.crate_name(LOCAL_CRATE),
-                    local_stable_crate_id.to_u64()
-                )
+                let local_crate_disambiguator = format!("{}", tcx.crate_disambiguator(LOCAL_CRATE));
+                format!("-in-{}.{}", tcx.crate_name(LOCAL_CRATE), &local_crate_disambiguator[0..8])
             } else {
                 String::new()
             };
 
-            let stable_crate_id = tcx.sess.local_stable_crate_id();
-            format!("{}.{:08x}{}", tcx.crate_name(cnum), stable_crate_id.to_u64(), local_crate_id)
+            let crate_disambiguator = tcx.crate_disambiguator(cnum).to_string();
+            // Using a shortened disambiguator of about 40 bits
+            format!("{}.{}{}", tcx.crate_name(cnum), &crate_disambiguator[0..8], local_crate_id)
         });
 
         write!(cgu_name, "{}", crate_prefix).unwrap();
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index ad624d8d113..0860520ef9d 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1237,6 +1237,10 @@ rustc_queries! {
     query proc_macro_decls_static(_: ()) -> Option<LocalDefId> {
         desc { "looking up the derive registrar for a crate" }
     }
+    query crate_disambiguator(_: CrateNum) -> CrateDisambiguator {
+        eval_always
+        desc { "looking up the disambiguator a crate" }
+    }
     // The macro which defines `rustc_metadata::provide_extern` depends on this query's name.
     // Changing the name should cause a compiler error, but in case that changes, be aware.
     query crate_hash(_: CrateNum) -> Svh {
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 970e669c16f..047b95f116e 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1275,24 +1275,24 @@ impl<'tcx> TyCtxt<'tcx> {
 
     pub fn def_path_debug_str(self, def_id: DefId) -> String {
         // We are explicitly not going through queries here in order to get
-        // crate name and stable crate id since this code is called from debug!()
+        // crate name and disambiguator since this code is called from debug!()
         // statements within the query system and we'd run into endless
         // recursion otherwise.
-        let (crate_name, stable_crate_id) = if def_id.is_local() {
-            (self.crate_name, self.sess.local_stable_crate_id())
+        let (crate_name, crate_disambiguator) = if def_id.is_local() {
+            (self.crate_name, self.sess.local_crate_disambiguator())
         } else {
             (
                 self.cstore.crate_name_untracked(def_id.krate),
-                self.def_path_hash(def_id.krate.as_def_id()).stable_crate_id(),
+                self.cstore.crate_disambiguator_untracked(def_id.krate),
             )
         };
 
         format!(
             "{}[{}]{}",
             crate_name,
-            // Don't print the whole stable crate id. That's just
+            // Don't print the whole crate disambiguator. That's just
             // annoying in debug output.
-            &(format!("{:08x}", stable_crate_id.to_u64()))[..4],
+            &(crate_disambiguator.to_fingerprint().to_hex())[..4],
             self.def_path(def_id).to_string_no_crate_verbose()
         )
     }
diff --git a/compiler/rustc_middle/src/ty/query/mod.rs b/compiler/rustc_middle/src/ty/query/mod.rs
index a5b540dcb70..297110ee3ec 100644
--- a/compiler/rustc_middle/src/ty/query/mod.rs
+++ b/compiler/rustc_middle/src/ty/query/mod.rs
@@ -47,6 +47,7 @@ use rustc_index::{bit_set::FiniteBitSet, vec::IndexVec};
 use rustc_serialize::opaque;
 use rustc_session::config::{EntryFnType, OptLevel, OutputFilenames, SymbolManglingVersion};
 use rustc_session::utils::NativeLibKind;
+use rustc_session::CrateDisambiguator;
 use rustc_target::spec::PanicStrategy;
 
 use rustc_ast as ast;
diff --git a/compiler/rustc_middle/src/ty/query/on_disk_cache.rs b/compiler/rustc_middle/src/ty/query/on_disk_cache.rs
index e473559812f..ebb52d8863f 100644
--- a/compiler/rustc_middle/src/ty/query/on_disk_cache.rs
+++ b/compiler/rustc_middle/src/ty/query/on_disk_cache.rs
@@ -18,7 +18,7 @@ use rustc_serialize::{
     opaque::{self, FileEncodeResult, FileEncoder, IntEncodedWithFixedSize},
     Decodable, Decoder, Encodable, Encoder,
 };
-use rustc_session::{Session, StableCrateId};
+use rustc_session::{CrateDisambiguator, Session};
 use rustc_span::hygiene::{
     ExpnDataDecodeMode, ExpnDataEncodeMode, ExpnId, HygieneDecodeContext, HygieneEncodeContext,
     SyntaxContext, SyntaxContextData,
@@ -52,7 +52,7 @@ pub struct OnDiskCache<'sess> {
     // session.
     current_diagnostics: Lock<FxHashMap<DepNodeIndex, Vec<Diagnostic>>>,
 
-    prev_cnums: Vec<(u32, StableCrateId)>,
+    prev_cnums: Vec<(u32, String, CrateDisambiguator)>,
     cnum_map: OnceCell<IndexVec<CrateNum, Option<CrateNum>>>,
 
     source_map: &'sess SourceMap,
@@ -120,7 +120,7 @@ pub struct OnDiskCache<'sess> {
 #[derive(Encodable, Decodable)]
 struct Footer {
     file_index_to_stable_id: FxHashMap<SourceFileIndex, StableSourceFileId>,
-    prev_cnums: Vec<(u32, StableCrateId)>,
+    prev_cnums: Vec<(u32, String, CrateDisambiguator)>,
     query_result_index: EncodedQueryResultIndex,
     diagnostics_index: EncodedQueryResultIndex,
     // The location of all allocations.
@@ -349,8 +349,9 @@ impl<'sess> OnDiskCache<'sess> {
             let prev_cnums: Vec<_> = sorted_cnums
                 .iter()
                 .map(|&cnum| {
-                    let stable_crate_id = tcx.def_path_hash(cnum.as_def_id()).stable_crate_id();
-                    (cnum.as_u32(), stable_crate_id)
+                    let crate_name = tcx.crate_name(cnum).to_string();
+                    let crate_disambiguator = tcx.crate_disambiguator(cnum);
+                    (cnum.as_u32(), crate_name, crate_disambiguator)
                 })
                 .collect();
 
@@ -574,23 +575,25 @@ impl<'sess> OnDiskCache<'sess> {
     // maps to None.
     fn compute_cnum_map(
         tcx: TyCtxt<'_>,
-        prev_cnums: &[(u32, StableCrateId)],
+        prev_cnums: &[(u32, String, CrateDisambiguator)],
     ) -> IndexVec<CrateNum, Option<CrateNum>> {
         tcx.dep_graph.with_ignore(|| {
             let current_cnums = tcx
                 .all_crate_nums(())
                 .iter()
                 .map(|&cnum| {
-                    let stable_crate_id = tcx.def_path_hash(cnum.as_def_id()).stable_crate_id();
-                    (stable_crate_id, cnum)
+                    let crate_name = tcx.crate_name(cnum).to_string();
+                    let crate_disambiguator = tcx.crate_disambiguator(cnum);
+                    ((crate_name, crate_disambiguator), cnum)
                 })
                 .collect::<FxHashMap<_, _>>();
 
             let map_size = prev_cnums.iter().map(|&(cnum, ..)| cnum).max().unwrap_or(0) + 1;
             let mut map = IndexVec::from_elem_n(None, map_size as usize);
 
-            for &(prev_cnum, stable_crate_id) in prev_cnums {
-                map[CrateNum::from_u32(prev_cnum)] = current_cnums.get(&stable_crate_id).cloned();
+            for &(prev_cnum, ref crate_name, crate_disambiguator) in prev_cnums {
+                let key = (crate_name.clone(), crate_disambiguator);
+                map[CrateNum::from_u32(prev_cnum)] = current_cnums.get(&key).cloned();
             }
 
             map[LOCAL_CRATE] = Some(LOCAL_CRATE);