Rollup merge of #41287 - nikomatsakis:incr-comp-refactor-trans, r=eddyb

Miscellneous refactorings of trans

This doesn't achieve any particular goal yet, but it's a collection of refactorings with the common goal of turning `SharedCrateContext` etc into stuff that we can use with on-demand and actually expect to hash in a stable fashion for incremental. Not there yet, clearly.

r? @eddyb
cc @michaelwoerister

Author: frewsxcv

src/librustc/middle/cstore.rs

@@ -53,7 +53,6 @@ pub use self::NativeLibraryKind::*;
 
 #[derive(Clone, Debug)]
 pub struct LinkMeta {
-    pub crate_name: Symbol,
     pub crate_hash: Svh,
 }
 

src/librustc/session/mod.rs

@@ -13,7 +13,6 @@ pub use self::code_stats::{SizeKind, TypeSizeInfo, VariantInfo};
 
 use dep_graph::DepGraph;
 use hir::def_id::{CrateNum, DefIndex};
-use hir::svh::Svh;
 use lint;
 use middle::cstore::CrateStore;
 use middle::dependency_format;
@@ -402,15 +401,14 @@ impl Session {
 
     /// Returns the symbol name for the registrar function,
     /// given the crate Svh and the function DefIndex.
-    pub fn generate_plugin_registrar_symbol(&self, svh: &Svh, index: DefIndex)
+    pub fn generate_plugin_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
                                             -> String {
-        format!("__rustc_plugin_registrar__{}_{}", svh, index.as_usize())
+        format!("__rustc_plugin_registrar__{}_{}", disambiguator, index.as_usize())
     }
 
-    pub fn generate_derive_registrar_symbol(&self,
-                                            svh: &Svh,
-                                            index: DefIndex) -> String {
-        format!("__rustc_derive_registrar__{}_{}", svh, index.as_usize())
+    pub fn generate_derive_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
+                                            -> String {
+        format!("__rustc_derive_registrar__{}_{}", disambiguator, index.as_usize())
     }
 
     pub fn sysroot<'a>(&'a self) -> &'a Path {

src/librustc_driver/driver.rs

@@ -1140,7 +1140,7 @@ pub fn phase_6_link_output(sess: &Session,
                            outputs: &OutputFilenames) {
     time(sess.time_passes(),
          "linking",
-         || link::link_binary(sess, trans, outputs, &trans.link.crate_name.as_str()));
+         || link::link_binary(sess, trans, outputs, &trans.crate_name.as_str()));
 }
 
 fn escape_dep_filename(filename: &str) -> String {

src/librustc_metadata/creader.rs

@@ -600,7 +600,7 @@ impl<'a> CrateLoader<'a> {
             Err(err) => self.sess.span_fatal(span, &err),
         };
 
-        let sym = self.sess.generate_derive_registrar_symbol(&root.hash,
+        let sym = self.sess.generate_derive_registrar_symbol(root.disambiguator,
                                                              root.macro_derive_registrar.unwrap());
         let registrar = unsafe {
             let sym = match lib.symbol(&sym) {
@@ -654,7 +654,7 @@ impl<'a> CrateLoader<'a> {
     /// Look for a plugin registrar. Returns library path, crate
     /// SVH and DefIndex of the registrar function.
     pub fn find_plugin_registrar(&mut self, span: Span, name: &str)
-                                 -> Option<(PathBuf, Svh, DefIndex)> {
+                                 -> Option<(PathBuf, Symbol, DefIndex)> {
         let ekrate = self.read_extension_crate(span, &ExternCrateInfo {
              name: Symbol::intern(name),
              ident: Symbol::intern(name),
@@ -675,7 +675,7 @@ impl<'a> CrateLoader<'a> {
         let root = ekrate.metadata.get_root();
         match (ekrate.dylib.as_ref(), root.plugin_registrar_fn) {
             (Some(dylib), Some(reg)) => {
-                Some((dylib.to_path_buf(), root.hash, reg))
+                Some((dylib.to_path_buf(), root.disambiguator, reg))
             }
             (None, Some(_)) => {
                 span_err!(self.sess, span, E0457,

src/librustc_metadata/encoder.rs

@@ -14,7 +14,7 @@ use schema::*;
 
 use rustc::middle::cstore::{LinkMeta, LinkagePreference, NativeLibrary,
                             EncodedMetadata, EncodedMetadataHash};
-use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefIndex, DefId};
+use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefIndex, DefId, LOCAL_CRATE};
 use rustc::hir::map::definitions::DefPathTable;
 use rustc::middle::dependency_format::Linkage;
 use rustc::middle::lang_items;
@@ -1380,7 +1380,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let link_meta = self.link_meta;
         let is_proc_macro = tcx.sess.crate_types.borrow().contains(&CrateTypeProcMacro);
         let root = self.lazy(&CrateRoot {
-            name: link_meta.crate_name,
+            name: tcx.crate_name(LOCAL_CRATE),
             triple: tcx.sess.opts.target_triple.clone(),
             hash: link_meta.crate_hash,
             disambiguator: tcx.sess.local_crate_disambiguator(),

src/librustc_plugin/load.rs

@@ -100,8 +100,8 @@ impl<'a> PluginLoader<'a> {
     fn load_plugin(&mut self, span: Span, name: &str, args: Vec<ast::NestedMetaItem>) {
         let registrar = self.reader.find_plugin_registrar(span, name);
 
-        if let Some((lib, svh, index)) = registrar {
-            let symbol = self.sess.generate_plugin_registrar_symbol(&svh, index);
+        if let Some((lib, disambiguator, index)) = registrar {
+            let symbol = self.sess.generate_plugin_registrar_symbol(disambiguator, index);
             let fun = self.dylink_registrar(span, lib, symbol);
             self.plugins.push(PluginRegistrar {
                 fun: fun,

src/librustc_trans/back/link.rs

@@ -47,7 +47,6 @@ use std::str;
 use flate;
 use syntax::ast;
 use syntax::attr;
-use syntax::symbol::Symbol;
 use syntax_pos::Span;
 
 /// The LLVM module name containing crate-metadata. This includes a `.` on
@@ -136,11 +135,8 @@ pub fn find_crate_name(sess: Option<&Session>,
     "rust_out".to_string()
 }
 
-pub fn build_link_meta(incremental_hashes_map: &IncrementalHashesMap,
-                       name: &str)
-                       -> LinkMeta {
+pub fn build_link_meta(incremental_hashes_map: &IncrementalHashesMap) -> LinkMeta {
     let r = LinkMeta {
-        crate_name: Symbol::intern(name),
         crate_hash: Svh::new(incremental_hashes_map[&DepNode::Krate].to_smaller_hash()),
     };
     info!("{:?}", r);

src/librustc_trans/back/symbol_export.rs

@@ -15,6 +15,7 @@ use back::symbol_names::symbol_name;
 use util::nodemap::FxHashMap;
 use rustc::hir::def_id::{DefId, CrateNum, LOCAL_CRATE};
 use rustc::session::config;
+use rustc::ty::TyCtxt;
 use syntax::attr;
 use trans_item::TransItem;
 
@@ -64,15 +65,15 @@ impl ExportedSymbols {
         }
 
         if let Some(id) = scx.sess().derive_registrar_fn.get() {
-            let svh = &scx.link_meta().crate_hash;
             let def_id = scx.tcx().hir.local_def_id(id);
             let idx = def_id.index;
-            let registrar = scx.sess().generate_derive_registrar_symbol(svh, idx);
+            let disambiguator = scx.sess().local_crate_disambiguator();
+            let registrar = scx.sess().generate_derive_registrar_symbol(disambiguator, idx);
             local_crate.push((registrar, SymbolExportLevel::C));
         }
 
         if scx.sess().crate_types.borrow().contains(&config::CrateTypeDylib) {
-            local_crate.push((scx.metadata_symbol_name(),
+            local_crate.push((metadata_symbol_name(scx.tcx()),
                               SymbolExportLevel::Rust));
         }
 
@@ -173,6 +174,12 @@ impl ExportedSymbols {
     }
 }
 
+pub fn metadata_symbol_name(tcx: TyCtxt) -> String {
+    format!("rust_metadata_{}_{}",
+            tcx.crate_name(LOCAL_CRATE),
+            tcx.crate_disambiguator(LOCAL_CRATE))
+}
+
 pub fn crate_export_threshold(crate_type: config::CrateType)
                                      -> SymbolExportLevel {
     match crate_type {

src/librustc_trans/back/symbol_names.rs

@@ -179,14 +179,14 @@ pub fn symbol_name<'a, 'tcx>(instance: Instance<'tcx>,
 
     if let Some(id) = node_id {
         if scx.sess().plugin_registrar_fn.get() == Some(id) {
-            let svh = &scx.link_meta().crate_hash;
             let idx = def_id.index;
-            return scx.sess().generate_plugin_registrar_symbol(svh, idx);
+            let disambiguator = scx.sess().local_crate_disambiguator();
+            return scx.sess().generate_plugin_registrar_symbol(disambiguator, idx);
         }
         if scx.sess().derive_registrar_fn.get() == Some(id) {
-            let svh = &scx.link_meta().crate_hash;
             let idx = def_id.index;
-            return scx.sess().generate_derive_registrar_symbol(svh, idx);
+            let disambiguator = scx.sess().local_crate_disambiguator();
+            return scx.sess().generate_derive_registrar_symbol(disambiguator, idx);
         }
     }