Rollup merge of #40678 - michaelwoerister:dmi-prep, r=nikomatsakis

Some preparations for directly computing the ICH of crate-metadata.

This PR contains some small fixes in preparation for direct metadata hashing. It mostly just moves stuff into places where it will be needed (making the module structure slightly cleaner along the way) and it fixes some omissions in the MIR region eraser.

r? @nikomatsakis

19 files changed, 87 insertions, 60 deletions

diff --git a/src/librustc_incremental/calculate_svh/caching_codemap_view.rs b/src/librustc/ich/caching_codemap_view.rs
index ad9c48420e2..a71251eedf5 100644
--- a/src/librustc_incremental/calculate_svh/caching_codemap_view.rs
+++ b/src/librustc/ich/caching_codemap_view.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use rustc::ty::TyCtxt;
+use ty::TyCtxt;
 use std::rc::Rc;
 use syntax::codemap::CodeMap;
 use syntax_pos::{BytePos, FileMap};
diff --git a/src/librustc_incremental/calculate_svh/def_path_hash.rs b/src/librustc/ich/def_path_hash.rs
index 8aa134ba3bf..03051dc0034 100644
--- a/src/librustc_incremental/calculate_svh/def_path_hash.rs
+++ b/src/librustc/ich/def_path_hash.rs
@@ -8,9 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use rustc::hir::def_id::DefId;
-use rustc::ty::TyCtxt;
-use rustc::util::nodemap::DefIdMap;
+use hir::def_id::DefId;
+use ty::TyCtxt;
+use util::nodemap::DefIdMap;
 
 pub struct DefPathHashes<'a, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
diff --git a/src/librustc_incremental/ich/fingerprint.rs b/src/librustc/ich/fingerprint.rs
index d296d8293fb..d296d8293fb 100644
--- a/src/librustc_incremental/ich/fingerprint.rs
+++ b/src/librustc/ich/fingerprint.rs
diff --git a/src/librustc/ich/mod.rs b/src/librustc/ich/mod.rs
new file mode 100644
index 00000000000..209953f3c68
--- /dev/null
+++ b/src/librustc/ich/mod.rs
@@ -0,0 +1,34 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub use self::fingerprint::Fingerprint;
+pub use self::def_path_hash::DefPathHashes;
+pub use self::caching_codemap_view::CachingCodemapView;
+
+mod fingerprint;
+mod def_path_hash;
+mod caching_codemap_view;
+
+pub const ATTR_DIRTY: &'static str = "rustc_dirty";
+pub const ATTR_CLEAN: &'static str = "rustc_clean";
+pub const ATTR_DIRTY_METADATA: &'static str = "rustc_metadata_dirty";
+pub const ATTR_CLEAN_METADATA: &'static str = "rustc_metadata_clean";
+pub const ATTR_IF_THIS_CHANGED: &'static str = "rustc_if_this_changed";
+pub const ATTR_THEN_THIS_WOULD_NEED: &'static str = "rustc_then_this_would_need";
+
+pub const IGNORED_ATTRIBUTES: &'static [&'static str] = &[
+    "cfg",
+    ATTR_IF_THIS_CHANGED,
+    ATTR_THEN_THIS_WOULD_NEED,
+    ATTR_DIRTY,
+    ATTR_CLEAN,
+    ATTR_DIRTY_METADATA,
+    ATTR_CLEAN_METADATA
+];
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index a007c9d2c43..c1c945d4e60 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -72,6 +72,7 @@ pub mod diagnostics;
 pub mod cfg;
 pub mod dep_graph;
 pub mod hir;
+pub mod ich;
 pub mod infer;
 pub mod lint;
 
diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index 1d816d342c4..1c1e0d91cb4 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -509,18 +509,21 @@ impl<'a, 'gcx, 'tcx, W> TypeVisitor<'tcx> for TypeIdHasher<'a, 'gcx, 'tcx, W>
     }
 
     fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+        self.hash_discriminant_u8(r);
         match *r {
-            ty::ReErased => {
-                self.hash::<u32>(0);
+            ty::ReErased |
+            ty::ReStatic |
+            ty::ReEmpty => {
+                // No variant fields to hash for these ...
             }
             ty::ReLateBound(db, ty::BrAnon(i)) => {
-                assert!(db.depth > 0);
-                self.hash::<u32>(db.depth);
+                self.hash(db.depth);
                 self.hash(i);
             }
-            ty::ReStatic |
-            ty::ReEmpty |
-            ty::ReEarlyBound(..) |
+            ty::ReEarlyBound(ty::EarlyBoundRegion { index, name }) => {
+                self.hash(index);
+                self.hash(name.as_str());
+            }
             ty::ReLateBound(..) |
             ty::ReFree(..) |
             ty::ReScope(..) |
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index c1ea2b9ce41..5d600270626 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -10,6 +10,7 @@
 
 use rustc::hir::{self, map as hir_map};
 use rustc::hir::lowering::lower_crate;
+use rustc::ich::Fingerprint;
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_mir as mir;
 use rustc::session::{Session, CompileResult, compile_result_from_err_count};
@@ -25,7 +26,6 @@ use rustc::util::nodemap::NodeSet;
 use rustc::util::fs::rename_or_copy_remove;
 use rustc_borrowck as borrowck;
 use rustc_incremental::{self, IncrementalHashesMap};
-use rustc_incremental::ich::Fingerprint;
 use rustc_resolve::{MakeGlobMap, Resolver};
 use rustc_metadata::creader::CrateLoader;
 use rustc_metadata::cstore::{self, CStore};
diff --git a/src/librustc_incremental/assert_dep_graph.rs b/src/librustc_incremental/assert_dep_graph.rs
index 287ee7dd13e..897ca0f2957 100644
--- a/src/librustc_incremental/assert_dep_graph.rs
+++ b/src/librustc_incremental/assert_dep_graph.rs
@@ -52,13 +52,13 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::graph::{Direction, INCOMING, OUTGOING, NodeIndex};
 use rustc::hir;
 use rustc::hir::itemlikevisit::ItemLikeVisitor;
+use rustc::ich::{ATTR_IF_THIS_CHANGED, ATTR_THEN_THIS_WOULD_NEED};
 use graphviz::IntoCow;
 use std::env;
 use std::fs::File;
 use std::io::Write;
 use syntax::ast;
 use syntax_pos::Span;
-use {ATTR_IF_THIS_CHANGED, ATTR_THEN_THIS_WOULD_NEED};
 
 pub fn assert_dep_graph<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
     let _ignore = tcx.dep_graph.in_ignore();
diff --git a/src/librustc_incremental/calculate_svh/mod.rs b/src/librustc_incremental/calculate_svh/mod.rs
index b9e6426dc01..c9496a4deb8 100644
--- a/src/librustc_incremental/calculate_svh/mod.rs
+++ b/src/librustc_incremental/calculate_svh/mod.rs
@@ -35,20 +35,16 @@ use rustc::hir;
 use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
 use rustc::hir::intravisit as visit;
 use rustc::hir::intravisit::{Visitor, NestedVisitorMap};
+use rustc::ich::{Fingerprint, DefPathHashes, CachingCodemapView};
 use rustc::ty::TyCtxt;
 use rustc_data_structures::stable_hasher::StableHasher;
-use ich::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
 use rustc::util::common::record_time;
 use rustc::session::config::DebugInfoLevel::NoDebugInfo;
 
-use self::def_path_hash::DefPathHashes;
 use self::svh_visitor::StrictVersionHashVisitor;
-use self::caching_codemap_view::CachingCodemapView;
 
-mod def_path_hash;
 mod svh_visitor;
-mod caching_codemap_view;
 
 pub type IchHasher = StableHasher<Fingerprint>;
 
diff --git a/src/librustc_incremental/calculate_svh/svh_visitor.rs b/src/librustc_incremental/calculate_svh/svh_visitor.rs
index fac49b29598..210803c3f32 100644
--- a/src/librustc_incremental/calculate_svh/svh_visitor.rs
+++ b/src/librustc_incremental/calculate_svh/svh_visitor.rs
@@ -26,23 +26,12 @@ use rustc::hir::*;
 use rustc::hir::def::Def;
 use rustc::hir::def_id::DefId;
 use rustc::hir::intravisit::{self as visit, Visitor};
+use rustc::ich::{DefPathHashes, CachingCodemapView, IGNORED_ATTRIBUTES};
 use rustc::ty::TyCtxt;
 use std::hash::{Hash, Hasher};
 
-use super::def_path_hash::DefPathHashes;
-use super::caching_codemap_view::CachingCodemapView;
 use super::IchHasher;
 
-const IGNORED_ATTRIBUTES: &'static [&'static str] = &[
-    "cfg",
-    ::ATTR_IF_THIS_CHANGED,
-    ::ATTR_THEN_THIS_WOULD_NEED,
-    ::ATTR_DIRTY,
-    ::ATTR_CLEAN,
-    ::ATTR_DIRTY_METADATA,
-    ::ATTR_CLEAN_METADATA
-];
-
 pub struct StrictVersionHashVisitor<'a, 'hash: 'a, 'tcx: 'hash> {
     pub tcx: TyCtxt<'hash, 'tcx, 'tcx>,
     pub st: &'a mut IchHasher,
diff --git a/src/librustc_incremental/ich/mod.rs b/src/librustc_incremental/ich/mod.rs
deleted file mode 100644
index 8edd04322d7..00000000000
--- a/src/librustc_incremental/ich/mod.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub use self::fingerprint::Fingerprint;
-
-mod fingerprint;
diff --git a/src/librustc_incremental/lib.rs b/src/librustc_incremental/lib.rs
index 0a8719c1253..3b61cc1464a 100644
--- a/src/librustc_incremental/lib.rs
+++ b/src/librustc_incremental/lib.rs
@@ -36,17 +36,9 @@ extern crate serialize as rustc_serialize;
 extern crate syntax;
 extern crate syntax_pos;
 
-const ATTR_DIRTY: &'static str = "rustc_dirty";
-const ATTR_CLEAN: &'static str = "rustc_clean";
-const ATTR_DIRTY_METADATA: &'static str = "rustc_metadata_dirty";
-const ATTR_CLEAN_METADATA: &'static str = "rustc_metadata_clean";
-const ATTR_IF_THIS_CHANGED: &'static str = "rustc_if_this_changed";
-const ATTR_THEN_THIS_WOULD_NEED: &'static str = "rustc_then_this_would_need";
-
 mod assert_dep_graph;
 mod calculate_svh;
 mod persist;
-pub mod ich;
 
 pub use assert_dep_graph::assert_dep_graph;
 pub use calculate_svh::compute_incremental_hashes_map;
diff --git a/src/librustc_incremental/persist/data.rs b/src/librustc_incremental/persist/data.rs
index 673f1ae1084..d9009073956 100644
--- a/src/librustc_incremental/persist/data.rs
+++ b/src/librustc_incremental/persist/data.rs
@@ -12,9 +12,9 @@
 
 use rustc::dep_graph::{DepNode, WorkProduct, WorkProductId};
 use rustc::hir::def_id::DefIndex;
+use rustc::ich::Fingerprint;
 use std::sync::Arc;
 use rustc_data_structures::fx::FxHashMap;
-use ich::Fingerprint;
 
 use super::directory::DefPathIndex;
 
diff --git a/src/librustc_incremental/persist/dirty_clean.rs b/src/librustc_incremental/persist/dirty_clean.rs
index 929249df0b1..d931f64d579 100644
--- a/src/librustc_incremental/persist/dirty_clean.rs
+++ b/src/librustc_incremental/persist/dirty_clean.rs
@@ -47,13 +47,12 @@ use rustc::hir;
 use rustc::hir::def_id::DefId;
 use rustc::hir::itemlikevisit::ItemLikeVisitor;
 use rustc::hir::intravisit;
+use rustc::ich::{Fingerprint, ATTR_DIRTY, ATTR_CLEAN, ATTR_DIRTY_METADATA,
+                 ATTR_CLEAN_METADATA};
 use syntax::ast::{self, Attribute, NestedMetaItem};
 use rustc_data_structures::fx::{FxHashSet, FxHashMap};
 use syntax_pos::Span;
 use rustc::ty::TyCtxt;
-use ich::Fingerprint;
-
-use {ATTR_DIRTY, ATTR_CLEAN, ATTR_DIRTY_METADATA, ATTR_CLEAN_METADATA};
 
 const LABEL: &'static str = "label";
 const CFG: &'static str = "cfg";
diff --git a/src/librustc_incremental/persist/hash.rs b/src/librustc_incremental/persist/hash.rs
index 799cb6c5e3d..9d8ff57e03b 100644
--- a/src/librustc_incremental/persist/hash.rs
+++ b/src/librustc_incremental/persist/hash.rs
@@ -11,6 +11,7 @@
 use rustc::dep_graph::DepNode;
 use rustc::hir::def_id::{CrateNum, DefId};
 use rustc::hir::svh::Svh;
+use rustc::ich::Fingerprint;
 use rustc::ty::TyCtxt;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::flock;
@@ -18,7 +19,6 @@ use rustc_serialize::Decodable;
 use rustc_serialize::opaque::Decoder;
 
 use IncrementalHashesMap;
-use ich::Fingerprint;
 use super::data::*;
 use super::fs::*;
 use super::file_format;
diff --git a/src/librustc_incremental/persist/load.rs b/src/librustc_incremental/persist/load.rs
index 27892506496..ed2e2e72ee7 100644
--- a/src/librustc_incremental/persist/load.rs
+++ b/src/librustc_incremental/persist/load.rs
@@ -13,6 +13,7 @@
 use rustc::dep_graph::{DepNode, WorkProductId};
 use rustc::hir::def_id::DefId;
 use rustc::hir::svh::Svh;
+use rustc::ich::Fingerprint;
 use rustc::session::Session;
 use rustc::ty::TyCtxt;
 use rustc_data_structures::fx::{FxHashSet, FxHashMap};
@@ -22,7 +23,6 @@ use std::path::{Path};
 use std::sync::Arc;
 
 use IncrementalHashesMap;
-use ich::Fingerprint;
 use super::data::*;
 use super::directory::*;
 use super::dirty_clean;
diff --git a/src/librustc_incremental/persist/preds/mod.rs b/src/librustc_incremental/persist/preds/mod.rs
index f6a37c7a122..fe8cf72996e 100644
--- a/src/librustc_incremental/persist/preds/mod.rs
+++ b/src/librustc_incremental/persist/preds/mod.rs
@@ -10,11 +10,11 @@
 
 use rustc::dep_graph::{DepGraphQuery, DepNode};
 use rustc::hir::def_id::DefId;
+use rustc::ich::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::graph::{Graph, NodeIndex};
 
 use super::hash::*;
-use ich::Fingerprint;
 
 mod compress;
 
diff --git a/src/librustc_incremental/persist/save.rs b/src/librustc_incremental/persist/save.rs
index dfa6bf6bbb5..2e518649337 100644
--- a/src/librustc_incremental/persist/save.rs
+++ b/src/librustc_incremental/persist/save.rs
@@ -11,6 +11,7 @@
 use rustc::dep_graph::DepNode;
 use rustc::hir::def_id::DefId;
 use rustc::hir::svh::Svh;
+use rustc::ich::Fingerprint;
 use rustc::session::Session;
 use rustc::ty::TyCtxt;
 use rustc_data_structures::fx::FxHashMap;
@@ -23,7 +24,6 @@ use std::fs::{self, File};
 use std::path::PathBuf;
 
 use IncrementalHashesMap;
-use ich::Fingerprint;
 use super::data::*;
 use super::directory::*;
 use super::hash::*;
diff --git a/src/librustc_mir/transform/erase_regions.rs b/src/librustc_mir/transform/erase_regions.rs
index cebd9dd9668..0f869e7ed02 100644
--- a/src/librustc_mir/transform/erase_regions.rs
+++ b/src/librustc_mir/transform/erase_regions.rs
@@ -13,7 +13,7 @@
 //! care erasing regions all over the place.
 
 use rustc::ty::subst::Substs;
-use rustc::ty::{Ty, TyCtxt};
+use rustc::ty::{Ty, TyCtxt, ReErased, ClosureSubsts};
 use rustc::mir::*;
 use rustc::mir::visit::MutVisitor;
 use rustc::mir::transform::{MirPass, MirSource, Pass};
@@ -39,6 +39,32 @@ impl<'a, 'tcx> MutVisitor<'tcx> for EraseRegionsVisitor<'a, 'tcx> {
     fn visit_substs(&mut self, substs: &mut &'tcx Substs<'tcx>) {
         *substs = self.tcx.erase_regions(&{*substs});
     }
+
+    fn visit_rvalue(&mut self, rvalue: &mut Rvalue<'tcx>, location: Location) {
+        match *rvalue {
+            Rvalue::Ref(ref mut r, _, _) => {
+                *r = self.tcx.mk_region(ReErased);
+            }
+            Rvalue::Use(..) |
+            Rvalue::Repeat(..) |
+            Rvalue::Len(..) |
+            Rvalue::Cast(..) |
+            Rvalue::BinaryOp(..) |
+            Rvalue::CheckedBinaryOp(..) |
+            Rvalue::UnaryOp(..) |
+            Rvalue::Discriminant(..) |
+            Rvalue::Box(..) |
+            Rvalue::Aggregate(..) => {
+                // These variants don't contain regions.
+            }
+        }
+        self.super_rvalue(rvalue, location);
+    }
+
+    fn visit_closure_substs(&mut self,
+                            substs: &mut ClosureSubsts<'tcx>) {
+        *substs = self.tcx.erase_regions(substs);
+    }
 }
 
 pub struct EraseRegions;