Build SymbolMap for symbol name conflict checking and caching.

michaelwoerister · michaelwoerister · commit 63c65e3556d3 · 2016-06-16T14:55:59.000-04:00
diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs
@@ -80,6 +80,7 @@ use meth;
 use mir;
 use monomorphize::{self, Instance};
 use partitioning::{self, PartitioningStrategy, CodegenUnit};
+use symbol_map::SymbolMap;
 use symbol_names_test;
 use trans_item::TransItem;
 use tvec;
@@ -97,6 +98,7 @@ use libc::c_uint;
 use std::ffi::{CStr, CString};
 use std::cell::{Cell, RefCell};
 use std::collections::{HashMap, HashSet};
+use std::rc::Rc;
 use std::str;
 use std::{i8, i16, i32, i64};
 use syntax::codemap::{Span, DUMMY_SP};
@@ -2589,14 +2591,18 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     };
     let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
 
-    let codegen_units = collect_and_partition_translation_items(&shared_ccx);
+    let (codegen_units, symbol_map) =
+        collect_and_partition_translation_items(&shared_ccx);
     let codegen_unit_count = codegen_units.len();
 
     assert!(tcx.sess.opts.cg.codegen_units == codegen_unit_count ||
             tcx.sess.opts.debugging_opts.incremental.is_some());
 
-    let crate_context_list = CrateContextList::new(&shared_ccx, codegen_units);
+    let symbol_map = Rc::new(symbol_map);
 
+    let crate_context_list = CrateContextList::new(&shared_ccx,
+                                                   codegen_units,
+                                                   symbol_map.clone());
     let modules = crate_context_list.iter()
         .map(|ccx| ModuleTranslation {
             name: String::from(&ccx.codegen_unit().name[..]),
@@ -2694,8 +2700,9 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     let sess = shared_ccx.sess();
     let mut reachable_symbols = shared_ccx.reachable().iter().map(|&id| {
         let def_id = shared_ccx.tcx().map.local_def_id(id);
-        Instance::mono(&shared_ccx, def_id).symbol_name(&shared_ccx)
+        symbol_for_def_id(def_id, &shared_ccx, &symbol_map)
     }).collect::<Vec<_>>();
+
     if sess.entry_fn.borrow().is_some() {
         reachable_symbols.push("main".to_string());
     }
@@ -2717,7 +2724,7 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         reachable_symbols.extend(syms.into_iter().filter(|did| {
             sess.cstore.is_extern_item(shared_ccx.tcx(), *did)
         }).map(|did| {
-            Instance::mono(&shared_ccx, did).symbol_name(&shared_ccx)
+            symbol_for_def_id(did, &shared_ccx, &symbol_map)
         }));
     }
 
@@ -2811,7 +2818,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for TransItemsWithinModVisitor<'a, 'tcx> {
 }
 
 fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>)
-                                                     -> Vec<CodegenUnit<'tcx>> {
+                                                     -> (Vec<CodegenUnit<'tcx>>, SymbolMap<'tcx>) {
     let time_passes = scx.sess().time_passes();
 
     let collection_mode = match scx.sess().opts.debugging_opts.print_trans_items {
@@ -2834,10 +2841,13 @@ fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a
         None => TransItemCollectionMode::Lazy
     };
 
-    let (items, inlining_map) = time(time_passes, "translation item collection", || {
-        collector::collect_crate_translation_items(&scx, collection_mode)
+    let (items, inlining_map) =
+        time(time_passes, "translation item collection", || {
+            collector::collect_crate_translation_items(&scx, collection_mode)
     });
 
+    let symbol_map = SymbolMap::build(scx, items.iter().cloned());
+
     let strategy = if scx.sess().opts.debugging_opts.incremental.is_some() {
         PartitioningStrategy::PerModule
     } else {
@@ -2911,5 +2921,24 @@ fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a
         }
     }
 
-    codegen_units
+    (codegen_units, symbol_map)
+}
+
+fn symbol_for_def_id<'a, 'tcx>(def_id: DefId,
+                               scx: &SharedCrateContext<'a, 'tcx>,
+                               symbol_map: &SymbolMap<'tcx>)
+                               -> String {
+    // Just try to look things up in the symbol map. If nothing's there, we
+    // recompute.
+    if let Some(node_id) = scx.tcx().map.as_local_node_id(def_id) {
+        if let Some(sym) = symbol_map.get(TransItem::Static(node_id)) {
+            return sym.to_owned();
+        }
+    }
+
+    let instance = Instance::mono(scx, def_id);
+
+    symbol_map.get(TransItem::Fn(instance))
+              .map(str::to_owned)
+              .unwrap_or_else(|| instance.symbol_name(scx))
 }
diff --git a/src/librustc_trans/callee.rs b/src/librustc_trans/callee.rs
@@ -46,6 +46,7 @@ use intrinsic;
 use machine::llalign_of_min;
 use meth;
 use monomorphize::{self, Instance};
+use trans_item::TransItem;
 use type_::Type;
 use type_of;
 use value::Value;
@@ -536,11 +537,18 @@ fn get_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
     // reference. It also occurs when testing libcore and in some
     // other weird situations. Annoying.
 
-    let sym = instance.symbol_name(ccx.shared());
+    // Let's see if we can get the symbol name from the symbol_map, so we don't
+    // have to recompute it.
+    let mut sym_data = String::new();
+    let sym = ccx.symbol_map().get(TransItem::Fn(instance)).unwrap_or_else(|| {
+        sym_data = instance.symbol_name(ccx.shared());
+        &sym_data[..]
+    });
+
     let llptrty = type_of::type_of(ccx, fn_ptr_ty);
-    let llfn = if let Some(llfn) = declare::get_declared_value(ccx, &sym) {
+    let llfn = if let Some(llfn) = declare::get_declared_value(ccx, sym) {
         if let Some(span) = local_item {
-            if declare::get_defined_value(ccx, &sym).is_some() {
+            if declare::get_defined_value(ccx, sym).is_some() {
                 ccx.sess().span_fatal(span,
                     &format!("symbol `{}` is already defined", sym));
             }
@@ -558,7 +566,7 @@ fn get_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
             llfn
         }
     } else {
-        let llfn = declare::declare_fn(ccx, &sym, ty);
+        let llfn = declare::declare_fn(ccx, sym, ty);
         assert_eq!(common::val_ty(llfn), llptrty);
         debug!("get_fn: not casting pointer!");
 
diff --git a/src/librustc_trans/consts.rs b/src/librustc_trans/consts.rs
@@ -1016,38 +1016,41 @@ pub fn get_static<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, def_id: DefId)
         return Datum::new(g, ty, Lvalue::new("static"));
     }
 
-    let sym = instance.symbol_name(ccx.shared());
-
     let g = if let Some(id) = ccx.tcx().map.as_local_node_id(def_id) {
+
         let llty = type_of::type_of(ccx, ty);
         let (g, attrs) = match ccx.tcx().map.get(id) {
             hir_map::NodeItem(&hir::Item {
                 ref attrs, span, node: hir::ItemStatic(..), ..
             }) => {
+                let sym = ccx.symbol_map()
+                             .get(TransItem::Static(id))
+                             .expect("Local statics should always be in the SymbolMap");
                 // Make sure that this is never executed for something inlined.
                 assert!(!ccx.external_srcs().borrow().contains_key(&id));
 
                 let defined_in_current_codegen_unit = ccx.codegen_unit()
                                                          .items
                                                          .contains_key(&TransItem::Static(id));
                 if defined_in_current_codegen_unit {
-                    if declare::get_declared_value(ccx, &sym).is_none() {
+                    if declare::get_declared_value(ccx, sym).is_none() {
                         span_bug!(span, "trans: Static not properly pre-defined?");
                     }
                 } else {
-                    if declare::get_declared_value(ccx, &sym).is_some() {
+                    if declare::get_declared_value(ccx, sym).is_some() {
                         span_bug!(span, "trans: Conflicting symbol names for static?");
                     }
                 }
 
-                let g = declare::define_global(ccx, &sym, llty).unwrap();
+                let g = declare::define_global(ccx, sym, llty).unwrap();
 
                 (g, attrs)
             }
 
             hir_map::NodeForeignItem(&hir::ForeignItem {
                 ref attrs, span, node: hir::ForeignItemStatic(..), ..
             }) => {
+                let sym = instance.symbol_name(ccx.shared());
                 let g = if let Some(name) =
                         attr::first_attr_value_str_by_name(&attrs, "linkage") {
                     // If this is a static with a linkage specified, then we need to handle
@@ -1082,7 +1085,7 @@ pub fn get_static<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, def_id: DefId)
                         real_name.push_str(&sym);
                         let g2 = declare::define_global(ccx, &real_name, llty).unwrap_or_else(||{
                             ccx.sess().span_fatal(span,
-                                &format!("symbol `{}` is already defined", sym))
+                                &format!("symbol `{}` is already defined", &sym))
                         });
                         llvm::SetLinkage(g2, llvm::InternalLinkage);
                         llvm::LLVMSetInitializer(g2, g1);
@@ -1107,6 +1110,8 @@ pub fn get_static<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, def_id: DefId)
 
         g
     } else {
+        let sym = instance.symbol_name(ccx.shared());
+
         // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
         // FIXME(nagisa): investigate whether it can be changed into define_global
         let g = declare::declare_global(ccx, &sym, type_of::type_of(ccx, ty));
diff --git a/src/librustc_trans/context.rs b/src/librustc_trans/context.rs
@@ -35,6 +35,7 @@ use rustc::ty::subst::{Substs, VecPerParamSpace};
 use rustc::ty::{self, Ty, TyCtxt};
 use session::config::NoDebugInfo;
 use session::Session;
+use symbol_map::SymbolMap;
 use util::sha2::Sha256;
 use util::nodemap::{NodeMap, NodeSet, DefIdMap, FnvHashMap};
 
@@ -171,6 +172,8 @@ pub struct LocalCrateContext<'tcx> {
 
     /// Depth of the current type-of computation - used to bail out
     type_of_depth: Cell<usize>,
+
+    symbol_map: Rc<SymbolMap<'tcx>>,
 }
 
 // Implement DepTrackingMapConfig for `trait_cache`
@@ -197,12 +200,13 @@ pub struct CrateContextList<'a, 'tcx: 'a> {
 impl<'a, 'tcx: 'a> CrateContextList<'a, 'tcx> {
 
     pub fn new(shared_ccx: &'a SharedCrateContext<'a, 'tcx>,
-               codegen_units: Vec<CodegenUnit<'tcx>>)
+               codegen_units: Vec<CodegenUnit<'tcx>>,
+               symbol_map: Rc<SymbolMap<'tcx>>)
                -> CrateContextList<'a, 'tcx> {
         CrateContextList {
             shared: shared_ccx,
             local_ccxs: codegen_units.into_iter().map(|codegen_unit| {
-                LocalCrateContext::new(shared_ccx, codegen_unit)
+                LocalCrateContext::new(shared_ccx, codegen_unit, symbol_map.clone())
             }).collect()
         }
     }
@@ -512,7 +516,8 @@ impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
 
 impl<'tcx> LocalCrateContext<'tcx> {
     fn new<'a>(shared: &SharedCrateContext<'a, 'tcx>,
-               codegen_unit: CodegenUnit<'tcx>)
+               codegen_unit: CodegenUnit<'tcx>,
+               symbol_map: Rc<SymbolMap<'tcx>>)
            -> LocalCrateContext<'tcx> {
         unsafe {
             // Append ".rs" to LLVM module identifier.
@@ -571,6 +576,7 @@ impl<'tcx> LocalCrateContext<'tcx> {
                 intrinsics: RefCell::new(FnvHashMap()),
                 n_llvm_insns: Cell::new(0),
                 type_of_depth: Cell::new(0),
+                symbol_map: symbol_map,
             };
 
             let (int_type, opaque_vec_type, str_slice_ty, mut local_ccx) = {
@@ -890,6 +896,10 @@ impl<'b, 'tcx> CrateContext<'b, 'tcx> {
         self.shared.get_mir(def_id)
     }
 
+    pub fn symbol_map(&self) -> &SymbolMap<'tcx> {
+        &*self.local().symbol_map
+    }
+
     pub fn translation_items(&self) -> &RefCell<FnvHashMap<TransItem<'tcx>, TransItemState>> {
         &self.shared.translation_items
     }
diff --git a/src/librustc_trans/lib.rs b/src/librustc_trans/lib.rs
@@ -121,6 +121,7 @@ mod meth;
 mod mir;
 mod monomorphize;
 mod partitioning;
+mod symbol_map;
 mod symbol_names_test;
 mod trans_item;
 mod tvec;
diff --git a/src/librustc_trans/monomorphize.rs b/src/librustc_trans/monomorphize.rs
@@ -84,19 +84,24 @@ pub fn monomorphic_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
         monomorphizing.insert(fn_id, depth + 1);
     }
 
-    let symbol = instance.symbol_name(ccx.shared());
+    // Let's see if we can get the symbol name from the symbol_map, so we don't
+    // have to recompute it.
+    let mut sym_data = String::new();
+    let symbol = ccx.symbol_map().get(TransItem::Fn(instance)).unwrap_or_else(|| {
+        sym_data = instance.symbol_name(ccx.shared());
+        &sym_data[..]
+    });
 
     debug!("monomorphize_fn mangled to {}", symbol);
-    assert!(declare::get_defined_value(ccx, &symbol).is_none());
+    assert!(declare::get_defined_value(ccx, symbol).is_none());
 
     // FIXME(nagisa): perhaps needs a more fine grained selection?
-    let lldecl = declare::define_internal_fn(ccx, &symbol, mono_ty);
+    let lldecl = declare::define_internal_fn(ccx, symbol, mono_ty);
     // FIXME(eddyb) Doubt all extern fn should allow unwinding.
     attributes::unwind(lldecl, true);
 
     ccx.instances().borrow_mut().insert(instance, lldecl);
 
-
     // we can only monomorphize things in this crate (or inlined into it)
     let fn_node_id = ccx.tcx().map.as_local_node_id(fn_id).unwrap();
     let map_node = errors::expect(
diff --git a/src/librustc_trans/symbol_map.rs b/src/librustc_trans/symbol_map.rs
diff --git a/src/librustc_trans/trans_item.rs b/src/librustc_trans/trans_item.rs
