Auto merge of #46427 - michaelwoerister:transitive-svh, r=nikomatsakis

incr.comp.: Incorporate the stable commandline arg hash and SVHs of upstream crates into the SVH.

So far the SVH detected changes in the HIR, which is already very sensitive, but in order for `eval_always` queries to also be sensitive to changes in upstream crates, the SVH also needs to capture changes there.

This PR fixes [rust-icci/crossbeam](https://travis-ci.org/rust-icci/crossbeam/builds/308936448), but I have not yet been able to come up with a minimal regression test.

r? @nikomatsakis

2 files changed, 23 insertions, 3 deletions

diff --git a/src/librustc/hir/map/collector.rs b/src/librustc/hir/map/collector.rs
index 5c1e74dcf43..02a1e33eeb9 100644
--- a/src/librustc/hir/map/collector.rs
+++ b/src/librustc/hir/map/collector.rs
@@ -12,6 +12,7 @@ use super::*;
 
 use dep_graph::{DepGraph, DepKind, DepNodeIndex};
 use hir::intravisit::{Visitor, NestedVisitorMap};
+use middle::cstore::CrateStore;
 use session::CrateDisambiguator;
 use std::iter::repeat;
 use syntax::ast::{NodeId, CRATE_NODE_ID};
@@ -119,7 +120,9 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
     }
 
     pub(super) fn finalize_and_compute_crate_hash(self,
-                                                  crate_disambiguator: CrateDisambiguator)
+                                                  crate_disambiguator: CrateDisambiguator,
+                                                  cstore: &CrateStore,
+                                                  commandline_args_hash: u64)
                                                   -> Vec<MapEntry<'hir>> {
         let mut node_hashes: Vec<_> = self
             .hir_body_nodes
@@ -132,9 +135,23 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
 
         node_hashes.sort_unstable_by(|&(ref d1, _), &(ref d2, _)| d1.cmp(d2));
 
+        let mut upstream_crates: Vec<_> = cstore.crates_untracked().iter().map(|&cnum| {
+            let name = cstore.crate_name_untracked(cnum).as_str();
+            let disambiguator = cstore.crate_disambiguator_untracked(cnum)
+                                      .to_fingerprint();
+            let hash = cstore.crate_hash_untracked(cnum);
+            (name, disambiguator, hash)
+        }).collect();
+
+        upstream_crates.sort_unstable_by(|&(name1, dis1, _), &(name2, dis2, _)| {
+            (name1, dis1).cmp(&(name2, dis2))
+        });
+
         self.dep_graph.with_task(DepNode::new_no_params(DepKind::Krate),
                                  &self.hcx,
-                                 (node_hashes, crate_disambiguator.to_fingerprint()),
+                                 ((node_hashes, upstream_crates),
+                                  (commandline_args_hash,
+                                   crate_disambiguator.to_fingerprint())),
                                  identity_fn);
         self.map
     }
diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs
index 8b00280b26b..28527b6f0bc 100644
--- a/src/librustc/hir/map/mod.rs
+++ b/src/librustc/hir/map/mod.rs
@@ -1059,7 +1059,10 @@ pub fn map_crate<'hir>(sess: &::session::Session,
         intravisit::walk_crate(&mut collector, &forest.krate);
 
         let crate_disambiguator = sess.local_crate_disambiguator();
-        collector.finalize_and_compute_crate_hash(crate_disambiguator)
+        let cmdline_args = sess.opts.dep_tracking_hash();
+        collector.finalize_and_compute_crate_hash(crate_disambiguator,
+                                                  cstore,
+                                                  cmdline_args)
     };
 
     if log_enabled!(::log::LogLevel::Debug) {