remove LinkMeta from SharedCrateContext

A number of things were using `crate_hash` that really ought to be using
`crate_disambiguator` (e.g., to create the plugin symbol names). They
have been updated.

It is important to remove `LinkMeta` from `SharedCrateContext` since it
contains a hash of the entire crate, and hence it will change
whenever **anything** changes (which would then require
rebuilding **everything**).

Author: nikomatsakis

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_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_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/symbol_export.rs

@@ -64,10 +64,10 @@ 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));
         }
 

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);
         }
     }
 

src/librustc_trans/base.rs

@@ -39,6 +39,7 @@ use middle::lang_items::StartFnLangItem;
 use middle::cstore::EncodedMetadata;
 use rustc::ty::{self, Ty, TyCtxt};
 use rustc::dep_graph::{AssertDepGraphSafe, DepNode};
+use rustc::middle::cstore::LinkMeta;
 use rustc::hir::map as hir_map;
 use rustc::util::common::time;
 use session::config::{self, NoDebugInfo};
@@ -725,6 +726,7 @@ fn contains_null(s: &str) -> bool {
 }
 
 fn write_metadata(cx: &SharedCrateContext,
+                  link_meta: &LinkMeta,
                   exported_symbols: &NodeSet)
                   -> (ContextRef, ModuleRef, EncodedMetadata) {
     use flate;
@@ -762,7 +764,7 @@ fn write_metadata(cx: &SharedCrateContext,
 
     let cstore = &cx.tcx().sess.cstore;
     let metadata = cstore.encode_metadata(cx.tcx(),
-                                          cx.link_meta(),
+                                          &link_meta,
                                           exported_symbols);
     if kind == MetadataKind::Uncompressed {
         return (metadata_llcx, metadata_llmod, metadata);
@@ -1071,13 +1073,12 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     let link_meta = link::build_link_meta(incremental_hashes_map);
 
     let shared_ccx = SharedCrateContext::new(tcx,
-                                             link_meta.clone(),
                                              exported_symbols,
                                              check_overflow);
     // Translate the metadata.
     let (metadata_llcx, metadata_llmod, metadata) =
         time(tcx.sess.time_passes(), "write metadata", || {
-            write_metadata(&shared_ccx, shared_ccx.exported_symbols())
+            write_metadata(&shared_ccx, &link_meta, shared_ccx.exported_symbols())
         });
 
     let metadata_module = ModuleTranslation {

src/librustc_trans/context.rs

@@ -11,7 +11,6 @@
 use llvm;
 use llvm::{ContextRef, ModuleRef, ValueRef};
 use rustc::dep_graph::{DepGraph, DepGraphSafe, DepNode, DepTrackingMap, DepTrackingMapConfig};
-use middle::cstore::LinkMeta;
 use rustc::hir;
 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
 use rustc::traits;
@@ -65,7 +64,6 @@ pub struct Stats {
 /// (aside from metadata-related ones).
 pub struct SharedCrateContext<'a, 'tcx: 'a> {
     exported_symbols: NodeSet,
-    link_meta: LinkMeta,
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     empty_param_env: ty::ParameterEnvironment<'tcx>,
     stats: Stats,
@@ -316,7 +314,6 @@ pub unsafe fn create_context_and_module(sess: &Session, mod_name: &str) -> (Cont
 
 impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
     pub fn new(tcx: TyCtxt<'b, 'tcx, 'tcx>,
-               link_meta: LinkMeta,
                exported_symbols: NodeSet,
                check_overflow: bool)
                -> SharedCrateContext<'b, 'tcx> {
@@ -367,7 +364,6 @@ impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
 
         SharedCrateContext {
             exported_symbols: exported_symbols,
-            link_meta: link_meta,
             empty_param_env: tcx.empty_parameter_environment(),
             tcx: tcx,
             stats: Stats {
@@ -409,10 +405,6 @@ impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
         &self.project_cache
     }
 
-    pub fn link_meta<'a>(&'a self) -> &'a LinkMeta {
-        &self.link_meta
-    }
-
     pub fn tcx<'a>(&'a self) -> TyCtxt<'a, 'tcx, 'tcx> {
         self.tcx
     }
@@ -440,7 +432,7 @@ impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
     pub fn metadata_symbol_name(&self) -> String {
         format!("rust_metadata_{}_{}",
                 self.tcx().crate_name(LOCAL_CRATE),
-                self.link_meta().crate_hash)
+                self.tcx().crate_disambiguator(LOCAL_CRATE))
     }
 }