From c97f5f0045f8ba959dc3b72cd705043ac7b4d9eb Mon Sep 17 00:00:00 2001 From: Tatsuyuki Ishi Date: Fri, 4 Oct 2019 22:55:10 +0900 Subject: [PATCH] Remove dead module --- src/librustc_mir/monomorphize/item.rs | 204 -------------------------- 1 file changed, 204 deletions(-) delete mode 100644 src/librustc_mir/monomorphize/item.rs diff --git a/src/librustc_mir/monomorphize/item.rs b/src/librustc_mir/monomorphize/item.rs deleted file mode 100644 index e63426281bf21..0000000000000 --- 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 { - 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 { - 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 - } -}