Rollup merge of #65158 - ishitatsuyuki:remove-dead, r=Mark-Simulacrum

Remove dead module

This module is not referenced any more. (A quick audit didn't show other stale files like this, so presumably this is the only one.)

1 files changed, 0 insertions, 204 deletions

diff --git a/src/librustc_mir/monomorphize/item.rs b/src/librustc_mir/monomorphize/item.rs
deleted file mode 100644
index e63426281bf..00000000000
--- a/src/librustc_mir/monomorphize/item.rs
+++ /dev/null
@@ -1,204 +0,0 @@
-use rustc::hir::def_id::LOCAL_CRATE;
-use rustc::mir::mono::MonoItem;
-use rustc::session::config::OptLevel;
-use rustc::ty::{self, TyCtxt, Instance};
-use rustc::ty::subst::InternalSubsts;
-use rustc::ty::print::obsolete::DefPathBasedNames;
-use syntax::attr::InlineAttr;
-use std::fmt;
-use rustc::mir::mono::Linkage;
-use syntax_pos::symbol::InternedString;
-use syntax::source_map::Span;
-
-/// Describes how a monomorphization will be instantiated in object files.
-#[derive(PartialEq, Eq, Clone, Copy, Debug, Hash)]
-pub enum InstantiationMode {
-    /// There will be exactly one instance of the given MonoItem. It will have
-    /// external linkage so that it can be linked to from other codegen units.
-    GloballyShared {
-        /// In some compilation scenarios we may decide to take functions that
-        /// are typically `LocalCopy` and instead move them to `GloballyShared`
-        /// to avoid codegenning them a bunch of times. In this situation,
-        /// however, our local copy may conflict with other crates also
-        /// inlining the same function.
-        ///
-        /// This flag indicates that this situation is occurring, and informs
-        /// symbol name calculation that some extra mangling is needed to
-        /// avoid conflicts. Note that this may eventually go away entirely if
-        /// ThinLTO enables us to *always* have a globally shared instance of a
-        /// function within one crate's compilation.
-        may_conflict: bool,
-    },
-
-    /// Each codegen unit containing a reference to the given MonoItem will
-    /// have its own private copy of the function (with internal linkage).
-    LocalCopy,
-}
-
-pub trait MonoItemExt<'tcx>: fmt::Debug {
-    fn as_mono_item(&self) -> &MonoItem<'tcx>;
-
-    fn is_generic_fn(&self) -> bool {
-        match *self.as_mono_item() {
-            MonoItem::Fn(ref instance) => {
-                instance.substs.non_erasable_generics().next().is_some()
-            }
-            MonoItem::Static(..) |
-            MonoItem::GlobalAsm(..) => false,
-        }
-    }
-
-    fn symbol_name(&self, tcx: TyCtxt<'tcx>) -> ty::SymbolName {
-        match *self.as_mono_item() {
-            MonoItem::Fn(instance) => tcx.symbol_name(instance),
-            MonoItem::Static(def_id) => {
-                tcx.symbol_name(Instance::mono(tcx, def_id))
-            }
-            MonoItem::GlobalAsm(hir_id) => {
-                let def_id = tcx.hir().local_def_id(hir_id);
-                ty::SymbolName {
-                    name: InternedString::intern(&format!("global_asm_{:?}", def_id))
-                }
-            }
-        }
-    }
-    fn instantiation_mode(&self, tcx: TyCtxt<'tcx>) -> InstantiationMode {
-        let inline_in_all_cgus =
-            tcx.sess.opts.debugging_opts.inline_in_all_cgus.unwrap_or_else(|| {
-                tcx.sess.opts.optimize != OptLevel::No
-            }) && !tcx.sess.opts.cg.link_dead_code;
-
-        match *self.as_mono_item() {
-            MonoItem::Fn(ref instance) => {
-                let entry_def_id = tcx.entry_fn(LOCAL_CRATE).map(|(id, _)| id);
-                // If this function isn't inlined or otherwise has explicit
-                // linkage, then we'll be creating a globally shared version.
-                if self.explicit_linkage(tcx).is_some() ||
-                    !instance.def.requires_local(tcx) ||
-                    Some(instance.def_id()) == entry_def_id
-                {
-                    return InstantiationMode::GloballyShared  { may_conflict: false }
-                }
-
-                // At this point we don't have explicit linkage and we're an
-                // inlined function. If we're inlining into all CGUs then we'll
-                // be creating a local copy per CGU
-                if inline_in_all_cgus {
-                    return InstantiationMode::LocalCopy
-                }
-
-                // Finally, if this is `#[inline(always)]` we're sure to respect
-                // that with an inline copy per CGU, but otherwise we'll be
-                // creating one copy of this `#[inline]` function which may
-                // conflict with upstream crates as it could be an exported
-                // symbol.
-                match tcx.codegen_fn_attrs(instance.def_id()).inline {
-                    InlineAttr::Always => InstantiationMode::LocalCopy,
-                    _ => {
-                        InstantiationMode::GloballyShared  { may_conflict: true }
-                    }
-                }
-            }
-            MonoItem::Static(..) |
-            MonoItem::GlobalAsm(..) => {
-                InstantiationMode::GloballyShared { may_conflict: false }
-            }
-        }
-    }
-
-    fn explicit_linkage(&self, tcx: TyCtxt<'tcx>) -> Option<Linkage> {
-        let def_id = match *self.as_mono_item() {
-            MonoItem::Fn(ref instance) => instance.def_id(),
-            MonoItem::Static(def_id) => def_id,
-            MonoItem::GlobalAsm(..) => return None,
-        };
-
-        let codegen_fn_attrs = tcx.codegen_fn_attrs(def_id);
-        codegen_fn_attrs.linkage
-    }
-
-    /// Returns `true` if this instance is instantiable - whether it has no unsatisfied
-    /// predicates.
-    ///
-    /// In order to codegen an item, all of its predicates must hold, because
-    /// otherwise the item does not make sense. Type-checking ensures that
-    /// the predicates of every item that is *used by* a valid item *do*
-    /// hold, so we can rely on that.
-    ///
-    /// However, we codegen collector roots (reachable items) and functions
-    /// in vtables when they are seen, even if they are not used, and so they
-    /// might not be instantiable. For example, a programmer can define this
-    /// public function:
-    ///
-    ///     pub fn foo<'a>(s: &'a mut ()) where &'a mut (): Clone {
-    ///         <&mut () as Clone>::clone(&s);
-    ///     }
-    ///
-    /// That function can't be codegened, because the method `<&mut () as Clone>::clone`
-    /// does not exist. Luckily for us, that function can't ever be used,
-    /// because that would require for `&'a mut (): Clone` to hold, so we
-    /// can just not emit any code, or even a linker reference for it.
-    ///
-    /// Similarly, if a vtable method has such a signature, and therefore can't
-    /// be used, we can just not emit it and have a placeholder (a null pointer,
-    /// which will never be accessed) in its place.
-    fn is_instantiable(&self, tcx: TyCtxt<'tcx>) -> bool {
-        debug!("is_instantiable({:?})", self);
-        let (def_id, substs) = match *self.as_mono_item() {
-            MonoItem::Fn(ref instance) => (instance.def_id(), instance.substs),
-            MonoItem::Static(def_id) => (def_id, InternalSubsts::empty()),
-            // global asm never has predicates
-            MonoItem::GlobalAsm(..) => return true
-        };
-
-        tcx.substitute_normalize_and_test_predicates((def_id, &substs))
-    }
-
-    fn to_string(&self, tcx: TyCtxt<'tcx>, debug: bool) -> String {
-        return match *self.as_mono_item() {
-            MonoItem::Fn(instance) => {
-                to_string_internal(tcx, "fn ", instance, debug)
-            },
-            MonoItem::Static(def_id) => {
-                let instance = Instance::new(def_id, tcx.intern_substs(&[]));
-                to_string_internal(tcx, "static ", instance, debug)
-            },
-            MonoItem::GlobalAsm(..) => {
-                "global_asm".to_string()
-            }
-        };
-
-        fn to_string_internal<'a, 'tcx>(
-            tcx: TyCtxt<'tcx>,
-            prefix: &str,
-            instance: Instance<'tcx>,
-            debug: bool,
-        ) -> String {
-            let mut result = String::with_capacity(32);
-            result.push_str(prefix);
-            let printer = DefPathBasedNames::new(tcx, false, false);
-            printer.push_instance_as_string(instance, &mut result, debug);
-            result
-        }
-    }
-
-    fn local_span(&self, tcx: TyCtxt<'tcx>) -> Option<Span> {
-        match *self.as_mono_item() {
-            MonoItem::Fn(Instance { def, .. }) => {
-                tcx.hir().as_local_hir_id(def.def_id())
-            }
-            MonoItem::Static(def_id) => {
-                tcx.hir().as_local_hir_id(def_id)
-            }
-            MonoItem::GlobalAsm(hir_id) => {
-                Some(hir_id)
-            }
-        }.map(|hir_id| tcx.hir().span(hir_id))
-    }
-}
-
-impl MonoItemExt<'tcx> for MonoItem<'tcx> {
-    fn as_mono_item(&self) -> &MonoItem<'tcx> {
-        self
-    }
-}