Auto merge of #46370 - michaelwoerister:rm-metadata-hashing, r=eddyb

incr.comp.: Remove ability to produce incr. comp. hashes during metadata export.

This functionality has been superseded by on-import hashing, which can be less conservative and does not require extra infrastructure.

r? @nikomatsakis

src/librustc/ich/mod.rs

@@ -28,8 +28,6 @@ mod impls_syntax;
 
 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 ATTR_PARTITION_REUSED: &'static str = "rustc_partition_reused";
@@ -41,8 +39,6 @@ pub const DEP_GRAPH_ASSERT_ATTRS: &'static [&'static str] = &[
     ATTR_THEN_THIS_WOULD_NEED,
     ATTR_DIRTY,
     ATTR_CLEAN,
-    ATTR_DIRTY_METADATA,
-    ATTR_CLEAN_METADATA,
     ATTR_PARTITION_REUSED,
     ATTR_PARTITION_TRANSLATED,
 ];
@@ -53,8 +49,6 @@ pub const IGNORED_ATTRIBUTES: &'static [&'static str] = &[
     ATTR_THEN_THIS_WOULD_NEED,
     ATTR_DIRTY,
     ATTR_CLEAN,
-    ATTR_DIRTY_METADATA,
-    ATTR_CLEAN_METADATA,
     ATTR_PARTITION_REUSED,
     ATTR_PARTITION_TRANSLATED,
 ];

src/librustc/middle/cstore.rs

@@ -175,32 +175,6 @@ impl EncodedMetadata {
     }
 }
 
-/// The hash for some metadata that (when saving) will be exported
-/// from this crate, or which (when importing) was exported by an
-/// upstream crate.
-#[derive(Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
-pub struct EncodedMetadataHash {
-    pub def_index: u32,
-    pub hash: ich::Fingerprint,
-}
-
-/// The hash for some metadata that (when saving) will be exported
-/// from this crate, or which (when importing) was exported by an
-/// upstream crate.
-#[derive(Debug, RustcEncodable, RustcDecodable, Clone)]
-pub struct EncodedMetadataHashes {
-    // Stable content hashes for things in crate metadata, indexed by DefIndex.
-    pub hashes: Vec<EncodedMetadataHash>,
-}
-
-impl EncodedMetadataHashes {
-    pub fn new() -> EncodedMetadataHashes {
-        EncodedMetadataHashes {
-            hashes: Vec::new(),
-        }
-    }
-}
-
 /// The backend's way to give the crate store access to the metadata in a library.
 /// Note that it returns the raw metadata bytes stored in the library file, whether
 /// it is compressed, uncompressed, some weird mix, etc.
@@ -286,7 +260,7 @@ pub trait CrateStore {
                                  tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                  link_meta: &LinkMeta,
                                  reachable: &NodeSet)
-                                 -> (EncodedMetadata, EncodedMetadataHashes);
+                                 -> EncodedMetadata;
     fn metadata_encoding_version(&self) -> &[u8];
 }
 
@@ -370,7 +344,7 @@ impl CrateStore for DummyCrateStore {
                                  tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                  link_meta: &LinkMeta,
                                  reachable: &NodeSet)
-                                 -> (EncodedMetadata, EncodedMetadataHashes) {
+                                 -> EncodedMetadata {
         bug!("encode_metadata")
     }
     fn metadata_encoding_version(&self) -> &[u8] { bug!("metadata_encoding_version") }

src/librustc/session/config.rs

@@ -1072,8 +1072,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "attempt to recover from parse errors (experimental)"),
     incremental: Option<String> = (None, parse_opt_string, [UNTRACKED],
           "enable incremental compilation (experimental)"),
-    incremental_cc: bool = (false, parse_bool, [UNTRACKED],
-          "enable cross-crate incremental compilation (even more experimental)"),
     incremental_queries: bool = (true, parse_bool, [UNTRACKED],
           "enable incremental compilation support for queries (experimental)"),
     incremental_info: bool = (false, parse_bool, [UNTRACKED],

src/librustc/ty/context.rs

@@ -24,7 +24,7 @@ use hir::map::DefPathHash;
 use lint::{self, Lint};
 use ich::{StableHashingContext, NodeIdHashingMode};
 use middle::const_val::ConstVal;
-use middle::cstore::{CrateStore, LinkMeta, EncodedMetadataHashes};
+use middle::cstore::{CrateStore, LinkMeta};
 use middle::cstore::EncodedMetadata;
 use middle::free_region::FreeRegionMap;
 use middle::lang_items;
@@ -1242,7 +1242,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
 impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> {
     pub fn encode_metadata(self, link_meta: &LinkMeta, reachable: &NodeSet)
-        -> (EncodedMetadata, EncodedMetadataHashes)
+        -> EncodedMetadata
     {
         self.cstore.encode_metadata(self, link_meta, reachable)
     }

src/librustc_incremental/persist/data.rs

@@ -11,9 +11,6 @@
 //! The data that we will serialize and deserialize.
 
 use rustc::dep_graph::{WorkProduct, WorkProductId};
-use rustc::hir::map::DefPathHash;
-use rustc::middle::cstore::EncodedMetadataHash;
-use rustc_data_structures::fx::FxHashMap;
 
 #[derive(Debug, RustcEncodable, RustcDecodable)]
 pub struct SerializedWorkProduct {
@@ -23,39 +20,3 @@ pub struct SerializedWorkProduct {
     /// work-product data itself
     pub work_product: WorkProduct,
 }
-
-/// Data for use when downstream crates get recompiled.
-#[derive(Debug, RustcEncodable, RustcDecodable)]
-pub struct SerializedMetadataHashes {
-    /// For each def-id defined in this crate that appears in the
-    /// metadata, we hash all the inputs that were used when producing
-    /// the metadata. We save this after compilation is done. Then,
-    /// when some downstream crate is being recompiled, it can compare
-    /// the hashes we saved against the hashes that it saw from
-    /// before; this will tell it which of the items in this crate
-    /// changed, which in turn implies what items in the downstream
-    /// crate need to be recompiled.
-    ///
-    /// Note that we store the def-ids here. This is because we don't
-    /// reload this file when we recompile this crate, we will just
-    /// regenerate it completely with the current hashes and new def-ids.
-    ///
-    /// Then downstream creates will load up their
-    /// `SerializedDepGraph`, which may contain `MetaData(X)` nodes
-    /// where `X` refers to some item in this crate. That `X` will be
-    /// a `DefPathIndex` that gets retracted to the current `DefId`
-    /// (matching the one found in this structure).
-    pub entry_hashes: Vec<EncodedMetadataHash>,
-
-    /// 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: FxHashMap<u32, DefPathHash>
-}

src/librustc_incremental/persist/dirty_clean.rs

@@ -23,21 +23,6 @@
 //! Errors are reported if we are in the suitable configuration but
 //! the required condition is not met.
 //!
-//! The `#[rustc_metadata_dirty]` and `#[rustc_metadata_clean]` attributes
-//! can be used to check the incremental compilation hash (ICH) values of
-//! metadata exported in rlibs.
-//!
-//! - If a node is marked with `#[rustc_metadata_clean(cfg="rev2")]` we
-//!   check that the metadata hash for that node is the same for "rev2"
-//!   it was for "rev1".
-//! - If a node is marked with `#[rustc_metadata_dirty(cfg="rev2")]` we
-//!   check that the metadata hash for that node is *different* for "rev2"
-//!   than it was for "rev1".
-//!
-//! Note that the metadata-testing attributes must never specify the
-//! first revision. This would lead to a crash since there is no
-//! previous revision to compare things to.
-//!
 
 use std::collections::HashSet;
 use std::iter::FromIterator;
@@ -49,10 +34,9 @@ use rustc::hir::map::Node as HirNode;
 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 rustc::ich::{ATTR_DIRTY, ATTR_CLEAN};
 use syntax::ast::{self, Attribute, NestedMetaItem};
-use rustc_data_structures::fx::{FxHashSet, FxHashMap};
+use rustc_data_structures::fx::FxHashSet;
 use syntax_pos::Span;
 use rustc::ty::TyCtxt;
 
@@ -553,157 +537,6 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for DirtyCleanVisitor<'a, 'tcx> {
     }
 }
 
-pub fn check_dirty_clean_metadata<'a, 'tcx>(
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    prev_metadata_hashes: &FxHashMap<DefId, Fingerprint>,
-    current_metadata_hashes: &FxHashMap<DefId, Fingerprint>)
-{
-    if !tcx.sess.opts.debugging_opts.query_dep_graph {
-        return;
-    }
-
-    tcx.dep_graph.with_ignore(||{
-        let krate = tcx.hir.krate();
-        let mut dirty_clean_visitor = DirtyCleanMetadataVisitor {
-            tcx,
-            prev_metadata_hashes,
-            current_metadata_hashes,
-            checked_attrs: FxHashSet(),
-        };
-        intravisit::walk_crate(&mut dirty_clean_visitor, krate);
-
-        let mut all_attrs = FindAllAttrs {
-            tcx,
-            attr_names: vec![ATTR_DIRTY_METADATA, ATTR_CLEAN_METADATA],
-            found_attrs: vec![],
-        };
-        intravisit::walk_crate(&mut all_attrs, krate);
-
-        // Note that we cannot use the existing "unused attribute"-infrastructure
-        // here, since that is running before trans. This is also the reason why
-        // all trans-specific attributes are `Whitelisted` in syntax::feature_gate.
-        all_attrs.report_unchecked_attrs(&dirty_clean_visitor.checked_attrs);
-    });
-}
-
-pub struct DirtyCleanMetadataVisitor<'a, 'tcx: 'a, 'm> {
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    prev_metadata_hashes: &'m FxHashMap<DefId, Fingerprint>,
-    current_metadata_hashes: &'m FxHashMap<DefId, Fingerprint>,
-    checked_attrs: FxHashSet<ast::AttrId>,
-}
-
-impl<'a, 'tcx, 'm> intravisit::Visitor<'tcx> for DirtyCleanMetadataVisitor<'a, 'tcx, 'm> {
-
-    fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'tcx> {
-        intravisit::NestedVisitorMap::All(&self.tcx.hir)
-    }
-
-    fn visit_item(&mut self, item: &'tcx hir::Item) {
-        self.check_item(item.id, item.span);
-        intravisit::walk_item(self, item);
-    }
-
-    fn visit_variant(&mut self,
-                     variant: &'tcx hir::Variant,
-                     generics: &'tcx hir::Generics,
-                     parent_id: ast::NodeId) {
-        if let Some(e) = variant.node.disr_expr {
-            self.check_item(e.node_id, variant.span);
-        }
-
-        intravisit::walk_variant(self, variant, generics, parent_id);
-    }
-
-    fn visit_variant_data(&mut self,
-                          variant_data: &'tcx hir::VariantData,
-                          _: ast::Name,
-                          _: &'tcx hir::Generics,
-                          _parent_id: ast::NodeId,
-                          span: Span) {
-        if self.tcx.hir.find(variant_data.id()).is_some() {
-            // VariantData that represent structs or tuples don't have a
-            // separate entry in the HIR map and checking them would error,
-            // so only check if this is an enum or union variant.
-            self.check_item(variant_data.id(), span);
-        }
-
-        intravisit::walk_struct_def(self, variant_data);
-    }
-
-    fn visit_trait_item(&mut self, item: &'tcx hir::TraitItem) {
-        self.check_item(item.id, item.span);
-        intravisit::walk_trait_item(self, item);
-    }
-
-    fn visit_impl_item(&mut self, item: &'tcx hir::ImplItem) {
-        self.check_item(item.id, item.span);
-        intravisit::walk_impl_item(self, item);
-    }
-
-    fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem) {
-        self.check_item(i.id, i.span);
-        intravisit::walk_foreign_item(self, i);
-    }
-
-    fn visit_struct_field(&mut self, s: &'tcx hir::StructField) {
-        self.check_item(s.id, s.span);
-        intravisit::walk_struct_field(self, s);
-    }
-}
-
-impl<'a, 'tcx, 'm> DirtyCleanMetadataVisitor<'a, 'tcx, 'm> {
-
-    fn check_item(&mut self, item_id: ast::NodeId, item_span: Span) {
-        let def_id = self.tcx.hir.local_def_id(item_id);
-
-        for attr in self.tcx.get_attrs(def_id).iter() {
-            if attr.check_name(ATTR_DIRTY_METADATA) {
-                if check_config(self.tcx, attr) {
-                    if self.checked_attrs.insert(attr.id) {
-                        self.assert_state(false, def_id, item_span);
-                    }
-                }
-            } else if attr.check_name(ATTR_CLEAN_METADATA) {
-                if check_config(self.tcx, attr) {
-                    if self.checked_attrs.insert(attr.id) {
-                        self.assert_state(true, def_id, item_span);
-                    }
-                }
-            }
-        }
-    }
-
-    fn assert_state(&self, should_be_clean: bool, def_id: DefId, span: Span) {
-        let item_path = self.tcx.item_path_str(def_id);
-        debug!("assert_state({})", item_path);
-
-        if let Some(&prev_hash) = self.prev_metadata_hashes.get(&def_id) {
-            let hashes_are_equal = prev_hash == self.current_metadata_hashes[&def_id];
-
-            if should_be_clean && !hashes_are_equal {
-                self.tcx.sess.span_err(
-                        span,
-                        &format!("Metadata hash of `{}` is dirty, but should be clean",
-                                 item_path));
-            }
-
-            let should_be_dirty = !should_be_clean;
-            if should_be_dirty && hashes_are_equal {
-                self.tcx.sess.span_err(
-                        span,
-                        &format!("Metadata hash of `{}` is clean, but should be dirty",
-                                 item_path));
-            }
-        } else {
-            self.tcx.sess.span_err(
-                        span,
-                        &format!("Could not find previous metadata hash of `{}`",
-                                 item_path));
-        }
-    }
-}
-
 /// Given a `#[rustc_dirty]` or `#[rustc_clean]` attribute, scan
 /// for a `cfg="foo"` attribute and check whether we have a cfg
 /// flag called `foo`.
@@ -759,7 +592,6 @@ fn expect_associated_value(tcx: TyCtxt, item: &NestedMetaItem) -> ast::Name {
     }
 }
 
-
 // A visitor that collects all #[rustc_dirty]/#[rustc_clean] attributes from
 // the HIR. It is used to verfiy that we really ran checks for all annotated
 // nodes.

src/librustc_incremental/persist/fs.rs

@@ -131,7 +131,6 @@ use rand::{thread_rng, Rng};
 const LOCK_FILE_EXT: &'static str = ".lock";
 const DEP_GRAPH_FILENAME: &'static str = "dep-graph.bin";
 const WORK_PRODUCTS_FILENAME: &'static str = "work-products.bin";
-const METADATA_HASHES_FILENAME: &'static str = "metadata.bin";
 const QUERY_CACHE_FILENAME: &'static str = "query-cache.bin";
 
 // We encode integers using the following base, so they are shorter than decimal
@@ -148,10 +147,6 @@ pub fn work_products_path(sess: &Session) -> PathBuf {
     in_incr_comp_dir_sess(sess, WORK_PRODUCTS_FILENAME)
 }
 
-pub fn metadata_hash_export_path(sess: &Session) -> PathBuf {
-    in_incr_comp_dir_sess(sess, METADATA_HASHES_FILENAME)
-}
-
 pub fn query_cache_path(sess: &Session) -> PathBuf {
     in_incr_comp_dir_sess(sess, QUERY_CACHE_FILENAME)
 }