incr.comp.: Track expanded spans instead of FileMaps.

12 files changed, 78 insertions, 139 deletions

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 291d0d7c937..38ad473e404 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -176,7 +176,6 @@ pub enum DepNode<D: Clone + Debug> {
     IsMirAvailable(D),
     ItemAttrs(D),
     FnArgNames(D),
-    FileMap(D, Arc<String>),
 }
 
 impl<D: Clone + Debug> DepNode<D> {
@@ -307,7 +306,6 @@ impl<D: Clone + Debug> DepNode<D> {
             ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
             IsMirAvailable(ref d) => op(d).map(IsMirAvailable),
             GlobalMetaData(ref d, kind) => op(d).map(|d| GlobalMetaData(d, kind)),
-            FileMap(ref d, ref file_name) => op(d).map(|d| FileMap(d, file_name.clone())),
         }
     }
 }
diff --git a/src/librustc/ich/caching_codemap_view.rs b/src/librustc/ich/caching_codemap_view.rs
index b21c3a2b216..9aecd8ad836 100644
--- a/src/librustc/ich/caching_codemap_view.rs
+++ b/src/librustc/ich/caching_codemap_view.rs
@@ -8,11 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use dep_graph::{DepGraph, DepNode};
-use hir::def_id::{DefId, CrateNum, CRATE_DEF_INDEX};
-use rustc_data_structures::bitvec::BitVector;
 use std::rc::Rc;
-use std::sync::Arc;
 use syntax::codemap::CodeMap;
 use syntax_pos::{BytePos, FileMap};
 use ty::TyCtxt;
@@ -31,14 +27,12 @@ pub struct CachingCodemapView<'tcx> {
     codemap: &'tcx CodeMap,
     line_cache: [CacheEntry; 3],
     time_stamp: usize,
-    dep_graph: DepGraph,
-    dep_tracking_reads: BitVector,
 }
 
 impl<'tcx> CachingCodemapView<'tcx> {
     pub fn new<'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> CachingCodemapView<'tcx> {
         let codemap = tcx.sess.codemap();
-        let files = codemap.files_untracked();
+        let files = codemap.files();
         let first_file = files[0].clone();
         let entry = CacheEntry {
             time_stamp: 0,
@@ -50,11 +44,9 @@ impl<'tcx> CachingCodemapView<'tcx> {
         };
 
         CachingCodemapView {
-            dep_graph: tcx.dep_graph.clone(),
             codemap: codemap,
             line_cache: [entry.clone(), entry.clone(), entry.clone()],
             time_stamp: 0,
-            dep_tracking_reads: BitVector::new(files.len()),
         }
     }
 
@@ -67,9 +59,6 @@ impl<'tcx> CachingCodemapView<'tcx> {
         for cache_entry in self.line_cache.iter_mut() {
             if pos >= cache_entry.line_start && pos < cache_entry.line_end {
                 cache_entry.time_stamp = self.time_stamp;
-                if self.dep_tracking_reads.insert(cache_entry.file_index) {
-                    self.dep_graph.read(dep_node(cache_entry));
-                }
 
                 return Some((cache_entry.file.clone(),
                              cache_entry.line_number,
@@ -90,7 +79,7 @@ impl<'tcx> CachingCodemapView<'tcx> {
         // If the entry doesn't point to the correct file, fix it up
         if pos < cache_entry.file.start_pos || pos >= cache_entry.file.end_pos {
             let file_valid;
-            let files = self.codemap.files_untracked();
+            let files = self.codemap.files();
 
             if files.len() > 0 {
                 let file_index = self.codemap.lookup_filemap_idx(pos);
@@ -120,21 +109,8 @@ impl<'tcx> CachingCodemapView<'tcx> {
         cache_entry.line_end = line_bounds.1;
         cache_entry.time_stamp = self.time_stamp;
 
-        if self.dep_tracking_reads.insert(cache_entry.file_index) {
-            self.dep_graph.read(dep_node(cache_entry));
-        }
-
         return Some((cache_entry.file.clone(),
                      cache_entry.line_number,
                      pos - cache_entry.line_start));
     }
 }
-
-fn dep_node(cache_entry: &CacheEntry) -> DepNode<DefId> {
-    let def_id = DefId {
-        krate: CrateNum::from_u32(cache_entry.file.crate_of_origin),
-        index: CRATE_DEF_INDEX,
-    };
-    let name = Arc::new(cache_entry.file.name.clone());
-    DepNode::FileMap(def_id, name)
-}
diff --git a/src/librustc/ich/hcx.rs b/src/librustc/ich/hcx.rs
index f25ec8ecd4d..f8dddc42e48 100644
--- a/src/librustc/ich/hcx.rs
+++ b/src/librustc/ich/hcx.rs
@@ -74,6 +74,11 @@ impl<'a, 'tcx: 'a> StableHashingContext<'a, 'tcx> {
         }
     }
 
+    pub fn force_span_hashing(mut self) -> Self {
+        self.hash_spans = true;
+        self
+    }
+
     #[inline]
     pub fn while_hashing_hir_bodies<F: FnOnce(&mut Self)>(&mut self,
                                                           hash_bodies: bool,
diff --git a/src/librustc/ich/impls_mir.rs b/src/librustc/ich/impls_mir.rs
index 3ff8ffb3505..d523d40ccd4 100644
--- a/src/librustc/ich/impls_mir.rs
+++ b/src/librustc/ich/impls_mir.rs
@@ -22,11 +22,55 @@ impl_stable_hash_for!(struct mir::SourceInfo { span, scope });
 impl_stable_hash_for!(enum mir::Mutability { Mut, Not });
 impl_stable_hash_for!(enum mir::BorrowKind { Shared, Unique, Mut });
 impl_stable_hash_for!(enum mir::LocalKind { Var, Temp, Arg, ReturnPointer });
-impl_stable_hash_for!(struct mir::LocalDecl<'tcx> { mutability, ty, name, source_info,
-is_user_variable});
+impl_stable_hash_for!(struct mir::LocalDecl<'tcx> {
+    mutability,
+    ty,
+    name,
+    source_info,
+    is_user_variable
+});
 impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, by_ref });
 impl_stable_hash_for!(struct mir::BasicBlockData<'tcx> { statements, terminator, is_cleanup });
-impl_stable_hash_for!(struct mir::Terminator<'tcx> { source_info, kind });
+
+impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Terminator<'tcx> {
+    #[inline]
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hasher: &mut StableHasher<W>) {
+        let mir::Terminator {
+            ref kind,
+            ref source_info,
+        } = *self;
+
+        let hash_spans_unconditionally = match *kind {
+            mir::TerminatorKind::Assert { .. } => {
+                // Assert terminators generate a panic message that contains the
+                // source location, so we always have to feed its span into the
+                // ICH.
+                true
+            }
+            mir::TerminatorKind::Goto { .. } |
+            mir::TerminatorKind::SwitchInt { .. } |
+            mir::TerminatorKind::Resume |
+            mir::TerminatorKind::Return |
+            mir::TerminatorKind::Unreachable |
+            mir::TerminatorKind::Drop { .. } |
+            mir::TerminatorKind::DropAndReplace { .. } |
+            mir::TerminatorKind::Call { .. } => false,
+        };
+
+        if hash_spans_unconditionally {
+            hcx.while_hashing_spans(true, |hcx| {
+                source_info.hash_stable(hcx, hasher);
+            })
+        } else {
+            source_info.hash_stable(hcx, hasher);
+        }
+
+        kind.hash_stable(hcx, hasher);
+    }
+}
+
 
 impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Local {
     #[inline]
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 814246330a4..28531893659 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -11,8 +11,9 @@
 pub use self::code_stats::{CodeStats, DataTypeKind, FieldInfo};
 pub use self::code_stats::{SizeKind, TypeSizeInfo, VariantInfo};
 
-use dep_graph::{DepGraph, DepNode};
-use hir::def_id::{DefId, CrateNum, DefIndex, CRATE_DEF_INDEX};
+use dep_graph::DepGraph;
+use hir::def_id::{CrateNum, DefIndex};
+
 use lint;
 use middle::cstore::CrateStore;
 use middle::dependency_format;
@@ -32,7 +33,7 @@ use syntax::parse::ParseSess;
 use syntax::symbol::Symbol;
 use syntax::{ast, codemap};
 use syntax::feature_gate::AttributeType;
-use syntax_pos::{Span, MultiSpan, FileMap};
+use syntax_pos::{Span, MultiSpan};
 
 use rustc_back::{LinkerFlavor, PanicStrategy};
 use rustc_back::target::Target;
@@ -46,7 +47,6 @@ use std::io::Write;
 use std::rc::Rc;
 use std::fmt;
 use std::time::Duration;
-use std::sync::Arc;
 
 mod code_stats;
 pub mod config;
@@ -626,21 +626,6 @@ pub fn build_session_(sopts: config::Options,
     };
     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
 
-    // Hook up the codemap with a callback that allows it to register FileMap
-    // accesses with the dependency graph.
-    let cm_depgraph = dep_graph.clone();
-    let codemap_dep_tracking_callback = Box::new(move |filemap: &FileMap| {
-        let def_id = DefId {
-            krate: CrateNum::from_u32(filemap.crate_of_origin),
-            index: CRATE_DEF_INDEX,
-        };
-        let name = Arc::new(filemap.name.clone());
-        let dep_node = DepNode::FileMap(def_id, name);
-
-        cm_depgraph.read(dep_node);
-    });
-    codemap.set_dep_tracking_callback(codemap_dep_tracking_callback);
-
     let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
     let default_sysroot = match sopts.maybe_sysroot {
         Some(_) => None,
diff --git a/src/librustc_incremental/calculate_svh/mod.rs b/src/librustc_incremental/calculate_svh/mod.rs
index c9ed9ad3c7d..f5727aa0a5e 100644
--- a/src/librustc_incremental/calculate_svh/mod.rs
+++ b/src/librustc_incremental/calculate_svh/mod.rs
@@ -29,10 +29,9 @@
 
 use std::cell::RefCell;
 use std::hash::Hash;
-use std::sync::Arc;
 use rustc::dep_graph::DepNode;
 use rustc::hir;
-use rustc::hir::def_id::{LOCAL_CRATE, CRATE_DEF_INDEX, DefId};
+use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
 use rustc::hir::itemlikevisit::ItemLikeVisitor;
 use rustc::ich::{Fingerprint, StableHashingContext};
 use rustc::ty::TyCtxt;
@@ -155,11 +154,6 @@ impl<'a, 'tcx: 'a> ComputeItemHashesVisitor<'a, 'tcx> {
                                         // We want to incoporate these into the
                                         // SVH.
                                     }
-                                    DepNode::FileMap(..) => {
-                                        // These don't make a semantic
-                                        // difference, filter them out.
-                                        return None
-                                    }
                                     DepNode::AllLocalTraitImpls => {
                                         // These are already covered by hashing
                                         // the HIR.
@@ -306,24 +300,6 @@ pub fn compute_incremental_hashes_map<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>)
             visitor.compute_and_store_ich_for_item_like(DepNode::HirBody(def_id), true, macro_def);
         }
 
-        for filemap in tcx.sess
-                          .codemap()
-                          .files_untracked()
-                          .iter()
-                          .filter(|fm| !fm.is_imported()) {
-            assert_eq!(LOCAL_CRATE.as_u32(), filemap.crate_of_origin);
-            let def_id = DefId {
-                krate: LOCAL_CRATE,
-                index: CRATE_DEF_INDEX,
-            };
-            let name = Arc::new(filemap.name.clone());
-            let dep_node = DepNode::FileMap(def_id, name);
-            let mut hasher = IchHasher::new();
-            filemap.hash_stable(&mut visitor.hcx, &mut hasher);
-            let fingerprint = hasher.finish();
-            visitor.hashes.insert(dep_node, fingerprint);
-        }
-
         visitor.compute_and_store_ich_for_trait_impls(krate);
     });
 
diff --git a/src/librustc_incremental/persist/hash.rs b/src/librustc_incremental/persist/hash.rs
index 2f727a80f01..6ab280be470 100644
--- a/src/librustc_incremental/persist/hash.rs
+++ b/src/librustc_incremental/persist/hash.rs
@@ -51,8 +51,7 @@ impl<'a, 'tcx> HashContext<'a, 'tcx> {
         match *dep_node {
             DepNode::Krate |
             DepNode::Hir(_) |
-            DepNode::HirBody(_) |
-            DepNode::FileMap(..) =>
+            DepNode::HirBody(_) =>
                 true,
             DepNode::MetaData(def_id) |
             DepNode::GlobalMetaData(def_id, _) => !def_id.is_local(),
@@ -77,20 +76,6 @@ impl<'a, 'tcx> HashContext<'a, 'tcx> {
                 Some(self.incremental_hashes_map[dep_node])
             }
 
-            DepNode::FileMap(def_id, ref name) => {
-                if def_id.is_local() {
-                    // We will have been able to retrace the DefId (which is
-                    // always the local CRATE_DEF_INDEX), but the file with the
-                    // given name might have been removed, so we use get() in
-                    // order to allow for that case.
-                    self.incremental_hashes_map.get(dep_node).map(|x| *x)
-                } else {
-                    Some(self.metadata_hash(DepNode::FileMap(def_id, name.clone()),
-                                            def_id.krate,
-                                            |this| &mut this.global_metadata_hashes))
-                }
-            }
-
             // MetaData from other crates is an *input* to us.
             // MetaData nodes from *our* crates are an *output*; we
             // don't hash them, but we do compute a hash for them and
@@ -242,7 +227,6 @@ impl<'a, 'tcx> HashContext<'a, 'tcx> {
             let def_id = DefId { krate: cnum, index: CRATE_DEF_INDEX };
             let dep_node = match dep_node {
                 DepNode::GlobalMetaData(_, kind) => DepNode::GlobalMetaData(def_id, kind),
-                DepNode::FileMap(_, name) => DepNode::FileMap(def_id, name),
                 other => {
                     bug!("unexpected DepNode variant: {:?}", other)
                 }
diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs
index 93fcdc455e5..317b14e4ad2 100644
--- a/src/librustc_metadata/encoder.rs
+++ b/src/librustc_metadata/encoder.rs
@@ -18,7 +18,7 @@ use rustc::middle::cstore::{LinkMeta, LinkagePreference, NativeLibrary,
 use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefIndex, DefId, LOCAL_CRATE};
 use rustc::hir::map::definitions::DefPathTable;
 use rustc::dep_graph::{DepNode, GlobalMetaDataKind};
-use rustc::ich::{StableHashingContext, Fingerprint};
+use rustc::ich::Fingerprint;
 use rustc::middle::dependency_format::Linkage;
 use rustc::middle::lang_items;
 use rustc::mir;
@@ -29,7 +29,6 @@ use rustc::session::config::{self, CrateTypeProcMacro};
 use rustc::util::nodemap::{FxHashMap, NodeSet};
 
 use rustc_serialize::{Encodable, Encoder, SpecializedEncoder, opaque};
-use rustc_data_structures::stable_hasher::{StableHasher, HashStable};
 
 use std::hash::Hash;
 use std::intrinsics;
@@ -37,7 +36,6 @@ use std::io::prelude::*;
 use std::io::Cursor;
 use std::path::Path;
 use std::rc::Rc;
-use std::sync::Arc;
 use std::u32;
 use syntax::ast::{self, CRATE_NODE_ID};
 use syntax::codemap::Spanned;
@@ -284,7 +282,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let codemap = self.tcx.sess.codemap();
         let all_filemaps = codemap.files();
 
-        let hcx = &mut StableHashingContext::new(self.tcx);
         let (working_dir, working_dir_was_remapped) = self.tcx.sess.working_dir.clone();
 
         let adapted = all_filemaps.iter()
@@ -316,21 +313,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                     adapted.name = abs_path;
                     Rc::new(adapted)
                 }
-            });
-
-        let filemaps: Vec<_> = if self.compute_ich {
-            adapted.inspect(|filemap| {
-                let mut hasher = StableHasher::new();
-                filemap.hash_stable(hcx, &mut hasher);
-                let fingerprint = hasher.finish();
-                let dep_node = DepNode::FileMap((), Arc::new(filemap.name.clone()));
-                self.metadata_hashes.global_hashes.push((dep_node, fingerprint));
-            }).collect()
-        } else {
-            adapted.collect()
-        };
+            })
+            .collect::<Vec<_>>();
 
-        self.lazy_seq_ref(filemaps.iter().map(|fm| &**fm))
+        self.lazy_seq_ref(adapted.iter().map(|rc| &**rc))
     }
 
     fn encode_crate_root(&mut self) -> Lazy<CrateRoot> {
diff --git a/src/librustc_metadata/isolated_encoder.rs b/src/librustc_metadata/isolated_encoder.rs
index 7722a7b10c9..ed1680fbfae 100644
--- a/src/librustc_metadata/isolated_encoder.rs
+++ b/src/librustc_metadata/isolated_encoder.rs
@@ -35,7 +35,17 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
             tcx: tcx,
             ecx: ecx,
             hcx: if compute_ich {
-                Some((StableHashingContext::new(tcx), StableHasher::new()))
+                // We are always hashing spans for things in metadata because
+                // don't know if a downstream crate will use them or not.
+                // Except when -Zquery-dep-graph is specified because we don't
+                // want to mess up our tests.
+                let hcx = if tcx.sess.opts.debugging_opts.query_dep_graph {
+                    StableHashingContext::new(tcx)
+                } else {
+                    StableHashingContext::new(tcx).force_span_hashing()
+                };
+
+                Some((hcx, StableHasher::new()))
             } else {
                 None
             }
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index d32c3ec5f46..bbe5bd4a10c 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -103,18 +103,11 @@ impl FileLoader for RealFileLoader {
 //
 
 pub struct CodeMap {
-    // The `files` field should not be visible outside of libsyntax so that we
-    // can do proper dependency tracking.
     pub(super) files: RefCell<Vec<Rc<FileMap>>>,
     file_loader: Box<FileLoader>,
     // This is used to apply the file path remapping as specified via
     // -Zremap-path-prefix to all FileMaps allocated within this CodeMap.
     path_mapping: FilePathMapping,
-    // The CodeMap will invoke this callback whenever a specific FileMap is
-    // accessed. The callback starts out as a no-op but when the dependency
-    // graph becomes available later during the compilation process, it is
-    // be replaced with something that notifies the dep-tracking system.
-    dep_tracking_callback: RefCell<Box<Fn(&FileMap)>>,
 }
 
 impl CodeMap {
@@ -123,7 +116,6 @@ impl CodeMap {
             files: RefCell::new(Vec::new()),
             file_loader: Box::new(RealFileLoader),
             path_mapping: path_mapping,
-            dep_tracking_callback: RefCell::new(Box::new(|_| {})),
         }
     }
 
@@ -134,7 +126,6 @@ impl CodeMap {
             files: RefCell::new(Vec::new()),
             file_loader: file_loader,
             path_mapping: path_mapping,
-            dep_tracking_callback: RefCell::new(Box::new(|_| {})),
         }
     }
 
@@ -142,10 +133,6 @@ impl CodeMap {
         &self.path_mapping
     }
 
-    pub fn set_dep_tracking_callback(&self, cb: Box<Fn(&FileMap)>) {
-        *self.dep_tracking_callback.borrow_mut() = cb;
-    }
-
     pub fn file_exists(&self, path: &Path) -> bool {
         self.file_loader.file_exists(path)
     }
@@ -156,15 +143,6 @@ impl CodeMap {
     }
 
     pub fn files(&self) -> Ref<Vec<Rc<FileMap>>> {
-        let files = self.files.borrow();
-        for file in files.iter() {
-            (self.dep_tracking_callback.borrow())(file);
-        }
-        files
-    }
-
-    /// Only use this if you do your own dependency tracking!
-    pub fn files_untracked(&self) -> Ref<Vec<Rc<FileMap>>> {
         self.files.borrow()
     }
 
@@ -311,8 +289,6 @@ impl CodeMap {
         let files = self.files.borrow();
         let f = (*files)[idx].clone();
 
-        (self.dep_tracking_callback.borrow())(&f);
-
         match f.lookup_line(pos) {
             Some(line) => Ok(FileMapAndLine { fm: f, line: line }),
             None => Err(f)
@@ -502,7 +478,6 @@ impl CodeMap {
     pub fn get_filemap(&self, filename: &str) -> Option<Rc<FileMap>> {
         for fm in self.files.borrow().iter() {
             if filename == fm.name {
-               (self.dep_tracking_callback.borrow())(fm);
                 return Some(fm.clone());
             }
         }
@@ -513,7 +488,6 @@ impl CodeMap {
     pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
         let idx = self.lookup_filemap_idx(bpos);
         let fm = (*self.files.borrow())[idx].clone();
-        (self.dep_tracking_callback.borrow())(&fm);
         let offset = bpos - fm.start_pos;
         FileMapAndBytePos {fm: fm, pos: offset}
     }
@@ -524,8 +498,6 @@ impl CodeMap {
         let files = self.files.borrow();
         let map = &(*files)[idx];
 
-        (self.dep_tracking_callback.borrow())(map);
-
         // The number of extra bytes due to multibyte chars in the FileMap
         let mut total_extra_bytes = 0;
 
diff --git a/src/test/incremental/rlib_cross_crate/auxiliary/a.rs b/src/test/incremental/rlib_cross_crate/auxiliary/a.rs
index ff5fd634714..1099aeb9217 100644
--- a/src/test/incremental/rlib_cross_crate/auxiliary/a.rs
+++ b/src/test/incremental/rlib_cross_crate/auxiliary/a.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // no-prefer-dynamic
+// compile-flags: -Z query-dep-graph
 
 #![crate_type="rlib"]
 
diff --git a/src/test/incremental/type_alias_cross_crate/auxiliary/a.rs b/src/test/incremental/type_alias_cross_crate/auxiliary/a.rs
index e1dba131770..2ae434071f2 100644
--- a/src/test/incremental/type_alias_cross_crate/auxiliary/a.rs
+++ b/src/test/incremental/type_alias_cross_crate/auxiliary/a.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// compile-flags: -Z query-dep-graph
+
 #![crate_type="rlib"]
 
 #[cfg(rpass1)]