Auto merge of #36370 - michaelwoerister:incr-comp-metadata-hashes-check, r=nikomatsakis

ICH: Add ability to test the ICH of exported metadata items.

Also adds an example test case for ICH testing.

r? @nikomatsakis

Author: bors

src/librustc_incremental/assert_dep_graph.rs

@@ -59,9 +59,7 @@ use std::io::Write;
 use syntax::ast;
 use syntax::parse::token::InternedString;
 use syntax_pos::Span;
-
-const IF_THIS_CHANGED: &'static str = "rustc_if_this_changed";
-const THEN_THIS_WOULD_NEED: &'static str = "rustc_then_this_would_need";
+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();
@@ -91,7 +89,7 @@ pub fn assert_dep_graph<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
         assert!(tcx.sess.opts.debugging_opts.query_dep_graph,
                 "cannot use the `#[{}]` or `#[{}]` annotations \
                  without supplying `-Z query-dep-graph`",
-                IF_THIS_CHANGED, THEN_THIS_WOULD_NEED);
+                ATTR_IF_THIS_CHANGED, ATTR_THEN_THIS_WOULD_NEED);
     }
 
     // Check paths.
@@ -125,7 +123,7 @@ impl<'a, 'tcx> IfThisChanged<'a, 'tcx> {
     fn process_attrs(&mut self, node_id: ast::NodeId, attrs: &[ast::Attribute]) {
         let def_id = self.tcx.map.local_def_id(node_id);
         for attr in attrs {
-            if attr.check_name(IF_THIS_CHANGED) {
+            if attr.check_name(ATTR_IF_THIS_CHANGED) {
                 let dep_node_interned = self.argument(attr);
                 let dep_node = match dep_node_interned {
                     None => DepNode::Hir(def_id),
@@ -141,7 +139,7 @@ impl<'a, 'tcx> IfThisChanged<'a, 'tcx> {
                     }
                 };
                 self.if_this_changed.push((attr.span, def_id, dep_node));
-            } else if attr.check_name(THEN_THIS_WOULD_NEED) {
+            } else if attr.check_name(ATTR_THEN_THIS_WOULD_NEED) {
                 let dep_node_interned = self.argument(attr);
                 let dep_node = match dep_node_interned {
                     Some(ref n) => {

src/librustc_incremental/calculate_svh/mod.rs

@@ -28,6 +28,7 @@
 //! at the beginning.
 
 use syntax::ast;
+use std::cell::RefCell;
 use std::hash::{Hash, SipHasher, Hasher};
 use rustc::dep_graph::DepNode;
 use rustc::hir;
@@ -46,7 +47,42 @@ mod def_path_hash;
 mod svh_visitor;
 mod caching_codemap_view;
 
-pub type IncrementalHashesMap = FnvHashMap<DepNode<DefId>, u64>;
+pub struct IncrementalHashesMap {
+    hashes: FnvHashMap<DepNode<DefId>, u64>,
+
+    // These are the metadata hashes for the current crate as they were stored
+    // during the last compilation session. They are only loaded if
+    // -Z query-dep-graph was specified and are needed for auto-tests using
+    // the #[rustc_metadata_dirty] and #[rustc_metadata_clean] attributes to
+    // check whether some metadata hash has changed in between two revisions.
+    pub prev_metadata_hashes: RefCell<FnvHashMap<DefId, u64>>,
+}
+
+impl IncrementalHashesMap {
+    pub fn new() -> IncrementalHashesMap {
+        IncrementalHashesMap {
+            hashes: FnvHashMap(),
+            prev_metadata_hashes: RefCell::new(FnvHashMap()),
+        }
+    }
+
+    pub fn insert(&mut self, k: DepNode<DefId>, v: u64) -> Option<u64> {
+        self.hashes.insert(k, v)
+    }
+
+    pub fn iter<'a>(&'a self) -> ::std::collections::hash_map::Iter<'a, DepNode<DefId>, u64> {
+        self.hashes.iter()
+    }
+}
+
+impl<'a> ::std::ops::Index<&'a DepNode<DefId>> for IncrementalHashesMap {
+    type Output = u64;
+
+    fn index(&self, index: &'a DepNode<DefId>) -> &u64 {
+        &self.hashes[index]
+    }
+}
+
 
 pub fn compute_incremental_hashes_map<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>)
                                                     -> IncrementalHashesMap {
@@ -55,7 +91,7 @@ pub fn compute_incremental_hashes_map<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>)
     let hash_spans = tcx.sess.opts.debuginfo != NoDebugInfo;
     let mut visitor = HashItemsVisitor {
         tcx: tcx,
-        hashes: FnvHashMap(),
+        hashes: IncrementalHashesMap::new(),
         def_path_hashes: DefPathHashes::new(tcx),
         codemap: CachingCodemapView::new(tcx),
         hash_spans: hash_spans,

src/librustc_incremental/calculate_svh/svh_visitor.rs

@@ -30,9 +30,15 @@ use std::hash::{Hash, SipHasher};
 use super::def_path_hash::DefPathHashes;
 use super::caching_codemap_view::CachingCodemapView;
 
-const IGNORED_ATTRIBUTES: &'static [&'static str] = &["cfg",
-                                                      "rustc_clean",
-                                                      "rustc_dirty"];
+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>,

src/librustc_incremental/lib.rs

@@ -35,6 +35,13 @@ extern crate serialize as rustc_serialize;
 #[macro_use] 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;

src/librustc_incremental/persist/data.rs

@@ -13,6 +13,7 @@
 use rustc::dep_graph::{DepNode, WorkProduct, WorkProductId};
 use rustc::hir::def_id::DefIndex;
 use std::sync::Arc;
+use rustc_data_structures::fnv::FnvHashMap;
 
 use super::directory::DefPathIndex;
 
@@ -93,6 +94,18 @@ pub struct SerializedMetadataHashes {
     /// a `DefPathIndex` that gets retracted to the current `DefId`
     /// (matching the one found in this structure).
     pub hashes: Vec<SerializedMetadataHash>,
+
+    /// For each DefIndex (as it occurs in SerializedMetadataHash), this
+    /// map stores the DefPathIndex (as it occurs in DefIdDirectory), so
+    /// that we can find the new DefId for a SerializedMetadataHash in a
+    /// subsequent compilation session.
+    ///
+    /// This map is only needed for running auto-tests using the
+    /// #[rustc_metadata_dirty] and #[rustc_metadata_clean] attributes, and
+    /// is only populated if -Z query-dep-graph is specified. It will be
+    /// empty otherwise. Importing crates are perfectly happy with just having
+    /// the DefIndex.
+    pub index_map: FnvHashMap<DefIndex, DefPathIndex>
 }
 
 /// The hash for some metadata that (when saving) will be exported

src/librustc_incremental/persist/directory.rs

@@ -178,7 +178,6 @@ impl<'a,'tcx> DefIdDirectoryBuilder<'a,'tcx> {
         &self.directory.paths[id.index as usize]
     }
 
-
     pub fn map(&mut self, node: &DepNode<DefId>) -> DepNode<DefPathIndex> {
         node.map_def(|&def_id| Some(self.add(def_id))).unwrap()
     }