| // Copyright 2016 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Walks the crate looking for items/impl-items/trait-items that have |
| //! either a `rustc_symbol_name` or `rustc_item_path` attribute and |
| //! generates an error giving, respectively, the symbol name or |
| //! item-path. This is used for unit testing the code that generates |
| //! paths etc in all kinds of annoying scenarios. |
| |
| use asm; |
| use attributes; |
| use base; |
| use consts; |
| use context::CrateContext; |
| use common; |
| use declare; |
| use llvm; |
| use monomorphize::Instance; |
| use rustc::hir; |
| use rustc::hir::def_id::DefId; |
| use rustc::middle::trans::{Linkage, Visibility}; |
| use rustc::session::config::OptLevel; |
| use rustc::traits; |
| use rustc::ty::{self, Ty, TyCtxt, TypeFoldable}; |
| use rustc::ty::subst::{Subst, Substs}; |
| use syntax::ast; |
| use syntax::attr::{self, InlineAttr}; |
| use syntax_pos::Span; |
| use syntax_pos::symbol::Symbol; |
| use type_of; |
| use std::fmt::{self, Write}; |
| use std::iter; |
| |
| pub use rustc::middle::trans::TransItem; |
| |
| /// Describes how a translation item 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 TransItem. 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 translating 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 occuring, 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 TransItem will |
| /// have its own private copy of the function (with internal linkage). |
| LocalCopy, |
| } |
| |
| pub trait TransItemExt<'a, 'tcx>: fmt::Debug { |
| fn as_trans_item(&self) -> &TransItem<'tcx>; |
| |
| fn define(&self, ccx: &CrateContext<'a, 'tcx>) { |
| debug!("BEGIN IMPLEMENTING '{} ({})' in cgu {}", |
| self.to_string(ccx.tcx()), |
| self.to_raw_string(), |
| ccx.codegen_unit().name()); |
| |
| match *self.as_trans_item() { |
| TransItem::Static(node_id) => { |
| let tcx = ccx.tcx(); |
| let item = tcx.hir.expect_item(node_id); |
| if let hir::ItemStatic(_, m, _) = item.node { |
| match consts::trans_static(&ccx, m, item.id, &item.attrs) { |
| Ok(_) => { /* Cool, everything's alright. */ }, |
| Err(err) => { |
| err.report(tcx, item.span, "static"); |
| } |
| }; |
| } else { |
| span_bug!(item.span, "Mismatch between hir::Item type and TransItem type") |
| } |
| } |
| TransItem::GlobalAsm(node_id) => { |
| let item = ccx.tcx().hir.expect_item(node_id); |
| if let hir::ItemGlobalAsm(ref ga) = item.node { |
| asm::trans_global_asm(ccx, ga); |
| } else { |
| span_bug!(item.span, "Mismatch between hir::Item type and TransItem type") |
| } |
| } |
| TransItem::Fn(instance) => { |
| base::trans_instance(&ccx, instance); |
| } |
| } |
| |
| debug!("END IMPLEMENTING '{} ({})' in cgu {}", |
| self.to_string(ccx.tcx()), |
| self.to_raw_string(), |
| ccx.codegen_unit().name()); |
| } |
| |
| fn predefine(&self, |
| ccx: &CrateContext<'a, 'tcx>, |
| linkage: Linkage, |
| visibility: Visibility) { |
| debug!("BEGIN PREDEFINING '{} ({})' in cgu {}", |
| self.to_string(ccx.tcx()), |
| self.to_raw_string(), |
| ccx.codegen_unit().name()); |
| |
| let symbol_name = self.symbol_name(ccx.tcx()); |
| |
| debug!("symbol {}", &symbol_name); |
| |
| match *self.as_trans_item() { |
| TransItem::Static(node_id) => { |
| predefine_static(ccx, node_id, linkage, visibility, &symbol_name); |
| } |
| TransItem::Fn(instance) => { |
| predefine_fn(ccx, instance, linkage, visibility, &symbol_name); |
| } |
| TransItem::GlobalAsm(..) => {} |
| } |
| |
| debug!("END PREDEFINING '{} ({})' in cgu {}", |
| self.to_string(ccx.tcx()), |
| self.to_raw_string(), |
| ccx.codegen_unit().name()); |
| } |
| |
| fn symbol_name(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> ty::SymbolName { |
| match *self.as_trans_item() { |
| TransItem::Fn(instance) => tcx.symbol_name(instance), |
| TransItem::Static(node_id) => { |
| let def_id = tcx.hir.local_def_id(node_id); |
| tcx.symbol_name(Instance::mono(tcx, def_id)) |
| } |
| TransItem::GlobalAsm(node_id) => { |
| let def_id = tcx.hir.local_def_id(node_id); |
| ty::SymbolName { |
| name: Symbol::intern(&format!("global_asm_{:?}", def_id)).as_str() |
| } |
| } |
| } |
| } |
| |
| fn local_span(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Option<Span> { |
| match *self.as_trans_item() { |
| TransItem::Fn(Instance { def, .. }) => { |
| tcx.hir.as_local_node_id(def.def_id()) |
| } |
| TransItem::Static(node_id) | |
| TransItem::GlobalAsm(node_id) => { |
| Some(node_id) |
| } |
| }.map(|node_id| tcx.hir.span(node_id)) |
| } |
| |
| fn instantiation_mode(&self, |
| tcx: TyCtxt<'a, 'tcx, '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 |
| }); |
| |
| match *self.as_trans_item() { |
| TransItem::Fn(ref instance) => { |
| // 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() || |
| !common::requests_inline(tcx, instance) |
| { |
| 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. |
| let attrs = instance.def.attrs(tcx); |
| match attr::find_inline_attr(Some(tcx.sess.diagnostic()), &attrs) { |
| InlineAttr::Always => InstantiationMode::LocalCopy, |
| _ => { |
| InstantiationMode::GloballyShared { may_conflict: true } |
| } |
| } |
| } |
| TransItem::Static(..) => { |
| InstantiationMode::GloballyShared { may_conflict: false } |
| } |
| TransItem::GlobalAsm(..) => { |
| InstantiationMode::GloballyShared { may_conflict: false } |
| } |
| } |
| } |
| |
| fn is_generic_fn(&self) -> bool { |
| match *self.as_trans_item() { |
| TransItem::Fn(ref instance) => { |
| instance.substs.types().next().is_some() |
| } |
| TransItem::Static(..) | |
| TransItem::GlobalAsm(..) => false, |
| } |
| } |
| |
| fn explicit_linkage(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Option<Linkage> { |
| let def_id = match *self.as_trans_item() { |
| TransItem::Fn(ref instance) => instance.def_id(), |
| TransItem::Static(node_id) => tcx.hir.local_def_id(node_id), |
| TransItem::GlobalAsm(..) => return None, |
| }; |
| |
| let attributes = tcx.get_attrs(def_id); |
| if let Some(name) = attr::first_attr_value_str_by_name(&attributes, "linkage") { |
| if let Some(linkage) = base::linkage_by_name(&name.as_str()) { |
| Some(linkage) |
| } else { |
| let span = tcx.hir.span_if_local(def_id); |
| if let Some(span) = span { |
| tcx.sess.span_fatal(span, "invalid linkage specified") |
| } else { |
| tcx.sess.fatal(&format!("invalid linkage specified: {}", name)) |
| } |
| } |
| } else { |
| None |
| } |
| } |
| |
| /// Returns whether this instance is instantiable - whether it has no unsatisfied |
| /// predicates. |
| /// |
| /// In order to translate 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 translate 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 translated, 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<'a, 'tcx, 'tcx>) -> bool { |
| debug!("is_instantiable({:?})", self); |
| let (def_id, substs) = match *self.as_trans_item() { |
| TransItem::Fn(ref instance) => (instance.def_id(), instance.substs), |
| TransItem::Static(node_id) => (tcx.hir.local_def_id(node_id), Substs::empty()), |
| // global asm never has predicates |
| TransItem::GlobalAsm(..) => return true |
| }; |
| |
| let predicates = tcx.predicates_of(def_id).predicates.subst(tcx, substs); |
| traits::normalize_and_test_predicates(tcx, predicates) |
| } |
| |
| fn to_string(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> String { |
| let hir_map = &tcx.hir; |
| |
| return match *self.as_trans_item() { |
| TransItem::Fn(instance) => { |
| to_string_internal(tcx, "fn ", instance) |
| }, |
| TransItem::Static(node_id) => { |
| let def_id = hir_map.local_def_id(node_id); |
| let instance = Instance::new(def_id, tcx.intern_substs(&[])); |
| to_string_internal(tcx, "static ", instance) |
| }, |
| TransItem::GlobalAsm(..) => { |
| "global_asm".to_string() |
| } |
| }; |
| |
| fn to_string_internal<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| prefix: &str, |
| instance: Instance<'tcx>) |
| -> 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); |
| result |
| } |
| } |
| |
| fn to_raw_string(&self) -> String { |
| match *self.as_trans_item() { |
| TransItem::Fn(instance) => { |
| format!("Fn({:?}, {})", |
| instance.def, |
| instance.substs.as_ptr() as usize) |
| } |
| TransItem::Static(id) => { |
| format!("Static({:?})", id) |
| } |
| TransItem::GlobalAsm(id) => { |
| format!("GlobalAsm({:?})", id) |
| } |
| } |
| } |
| } |
| |
| impl<'a, 'tcx> TransItemExt<'a, 'tcx> for TransItem<'tcx> { |
| fn as_trans_item(&self) -> &TransItem<'tcx> { |
| self |
| } |
| } |
| |
| fn predefine_static<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, |
| node_id: ast::NodeId, |
| linkage: Linkage, |
| visibility: Visibility, |
| symbol_name: &str) { |
| let def_id = ccx.tcx().hir.local_def_id(node_id); |
| let instance = Instance::mono(ccx.tcx(), def_id); |
| let ty = common::instance_ty(ccx.tcx(), &instance); |
| let llty = type_of::type_of(ccx, ty); |
| |
| let g = declare::define_global(ccx, symbol_name, llty).unwrap_or_else(|| { |
| ccx.sess().span_fatal(ccx.tcx().hir.span(node_id), |
| &format!("symbol `{}` is already defined", symbol_name)) |
| }); |
| |
| unsafe { |
| llvm::LLVMRustSetLinkage(g, base::linkage_to_llvm(linkage)); |
| llvm::LLVMRustSetVisibility(g, base::visibility_to_llvm(visibility)); |
| } |
| |
| ccx.instances().borrow_mut().insert(instance, g); |
| ccx.statics().borrow_mut().insert(g, def_id); |
| } |
| |
| fn predefine_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, |
| instance: Instance<'tcx>, |
| linkage: Linkage, |
| visibility: Visibility, |
| symbol_name: &str) { |
| assert!(!instance.substs.needs_infer() && |
| !instance.substs.has_param_types()); |
| |
| let mono_ty = common::instance_ty(ccx.tcx(), &instance); |
| let attrs = instance.def.attrs(ccx.tcx()); |
| let lldecl = declare::declare_fn(ccx, symbol_name, mono_ty); |
| unsafe { llvm::LLVMRustSetLinkage(lldecl, base::linkage_to_llvm(linkage)) }; |
| base::set_link_section(ccx, lldecl, &attrs); |
| if linkage == Linkage::LinkOnceODR || |
| linkage == Linkage::WeakODR { |
| llvm::SetUniqueComdat(ccx.llmod(), lldecl); |
| } |
| |
| // If we're compiling the compiler-builtins crate, e.g. the equivalent of |
| // compiler-rt, then we want to implicitly compile everything with hidden |
| // visibility as we're going to link this object all over the place but |
| // don't want the symbols to get exported. |
| if linkage != Linkage::Internal && linkage != Linkage::Private && |
| attr::contains_name(ccx.tcx().hir.krate_attrs(), "compiler_builtins") { |
| unsafe { |
| llvm::LLVMRustSetVisibility(lldecl, llvm::Visibility::Hidden); |
| } |
| } else { |
| unsafe { |
| llvm::LLVMRustSetVisibility(lldecl, base::visibility_to_llvm(visibility)); |
| } |
| } |
| |
| debug!("predefine_fn: mono_ty = {:?} instance = {:?}", mono_ty, instance); |
| if common::is_inline_instance(ccx.tcx(), &instance) { |
| attributes::inline(lldecl, attributes::InlineAttr::Hint); |
| } |
| attributes::from_fn_attrs(ccx, &attrs, lldecl); |
| |
| ccx.instances().borrow_mut().insert(instance, lldecl); |
| } |
| |
| //=----------------------------------------------------------------------------- |
| // TransItem String Keys |
| //=----------------------------------------------------------------------------- |
| |
| // The code below allows for producing a unique string key for a trans item. |
| // These keys are used by the handwritten auto-tests, so they need to be |
| // predictable and human-readable. |
| // |
| // Note: A lot of this could looks very similar to what's already in the |
| // ppaux module. It would be good to refactor things so we only have one |
| // parameterizable implementation for printing types. |
| |
| /// Same as `unique_type_name()` but with the result pushed onto the given |
| /// `output` parameter. |
| pub struct DefPathBasedNames<'a, 'tcx: 'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| omit_disambiguators: bool, |
| omit_local_crate_name: bool, |
| } |
| |
| impl<'a, 'tcx> DefPathBasedNames<'a, 'tcx> { |
| pub fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| omit_disambiguators: bool, |
| omit_local_crate_name: bool) |
| -> Self { |
| DefPathBasedNames { |
| tcx, |
| omit_disambiguators, |
| omit_local_crate_name, |
| } |
| } |
| |
| pub fn push_type_name(&self, t: Ty<'tcx>, output: &mut String) { |
| match t.sty { |
| ty::TyBool => output.push_str("bool"), |
| ty::TyChar => output.push_str("char"), |
| ty::TyStr => output.push_str("str"), |
| ty::TyNever => output.push_str("!"), |
| ty::TyInt(ast::IntTy::Is) => output.push_str("isize"), |
| ty::TyInt(ast::IntTy::I8) => output.push_str("i8"), |
| ty::TyInt(ast::IntTy::I16) => output.push_str("i16"), |
| ty::TyInt(ast::IntTy::I32) => output.push_str("i32"), |
| ty::TyInt(ast::IntTy::I64) => output.push_str("i64"), |
| ty::TyInt(ast::IntTy::I128) => output.push_str("i128"), |
| ty::TyUint(ast::UintTy::Us) => output.push_str("usize"), |
| ty::TyUint(ast::UintTy::U8) => output.push_str("u8"), |
| ty::TyUint(ast::UintTy::U16) => output.push_str("u16"), |
| ty::TyUint(ast::UintTy::U32) => output.push_str("u32"), |
| ty::TyUint(ast::UintTy::U64) => output.push_str("u64"), |
| ty::TyUint(ast::UintTy::U128) => output.push_str("u128"), |
| ty::TyFloat(ast::FloatTy::F32) => output.push_str("f32"), |
| ty::TyFloat(ast::FloatTy::F64) => output.push_str("f64"), |
| ty::TyAdt(adt_def, substs) => { |
| self.push_def_path(adt_def.did, output); |
| self.push_type_params(substs, iter::empty(), output); |
| }, |
| ty::TyTuple(component_types, _) => { |
| output.push('('); |
| for &component_type in component_types { |
| self.push_type_name(component_type, output); |
| output.push_str(", "); |
| } |
| if !component_types.is_empty() { |
| output.pop(); |
| output.pop(); |
| } |
| output.push(')'); |
| }, |
| ty::TyRawPtr(ty::TypeAndMut { ty: inner_type, mutbl } ) => { |
| output.push('*'); |
| match mutbl { |
| hir::MutImmutable => output.push_str("const "), |
| hir::MutMutable => output.push_str("mut "), |
| } |
| |
| self.push_type_name(inner_type, output); |
| }, |
| ty::TyRef(_, ty::TypeAndMut { ty: inner_type, mutbl }) => { |
| output.push('&'); |
| if mutbl == hir::MutMutable { |
| output.push_str("mut "); |
| } |
| |
| self.push_type_name(inner_type, output); |
| }, |
| ty::TyArray(inner_type, len) => { |
| output.push('['); |
| self.push_type_name(inner_type, output); |
| write!(output, "; {}", |
| len.val.to_const_int().unwrap().to_u64().unwrap()).unwrap(); |
| output.push(']'); |
| }, |
| ty::TySlice(inner_type) => { |
| output.push('['); |
| self.push_type_name(inner_type, output); |
| output.push(']'); |
| }, |
| ty::TyDynamic(ref trait_data, ..) => { |
| if let Some(principal) = trait_data.principal() { |
| self.push_def_path(principal.def_id(), output); |
| self.push_type_params(principal.skip_binder().substs, |
| trait_data.projection_bounds(), |
| output); |
| } |
| }, |
| ty::TyFnDef(..) | |
| ty::TyFnPtr(_) => { |
| let sig = t.fn_sig(self.tcx); |
| if sig.unsafety() == hir::Unsafety::Unsafe { |
| output.push_str("unsafe "); |
| } |
| |
| let abi = sig.abi(); |
| if abi != ::abi::Abi::Rust { |
| output.push_str("extern \""); |
| output.push_str(abi.name()); |
| output.push_str("\" "); |
| } |
| |
| output.push_str("fn("); |
| |
| let sig = self.tcx.erase_late_bound_regions_and_normalize(&sig); |
| |
| if !sig.inputs().is_empty() { |
| for ¶meter_type in sig.inputs() { |
| self.push_type_name(parameter_type, output); |
| output.push_str(", "); |
| } |
| output.pop(); |
| output.pop(); |
| } |
| |
| if sig.variadic { |
| if !sig.inputs().is_empty() { |
| output.push_str(", ..."); |
| } else { |
| output.push_str("..."); |
| } |
| } |
| |
| output.push(')'); |
| |
| if !sig.output().is_nil() { |
| output.push_str(" -> "); |
| self.push_type_name(sig.output(), output); |
| } |
| }, |
| ty::TyGenerator(def_id, ref closure_substs, _) | |
| ty::TyClosure(def_id, ref closure_substs) => { |
| self.push_def_path(def_id, output); |
| let generics = self.tcx.generics_of(self.tcx.closure_base_def_id(def_id)); |
| let substs = closure_substs.substs.truncate_to(self.tcx, generics); |
| self.push_type_params(substs, iter::empty(), output); |
| } |
| ty::TyError | |
| ty::TyInfer(_) | |
| ty::TyProjection(..) | |
| ty::TyParam(_) | |
| ty::TyAnon(..) => { |
| bug!("DefPathBasedNames: Trying to create type name for \ |
| unexpected type: {:?}", t); |
| } |
| } |
| } |
| |
| pub fn push_def_path(&self, |
| def_id: DefId, |
| output: &mut String) { |
| let def_path = self.tcx.def_path(def_id); |
| |
| // some_crate:: |
| if !(self.omit_local_crate_name && def_id.is_local()) { |
| output.push_str(&self.tcx.crate_name(def_path.krate).as_str()); |
| output.push_str("::"); |
| } |
| |
| // foo::bar::ItemName:: |
| for part in self.tcx.def_path(def_id).data { |
| if self.omit_disambiguators { |
| write!(output, "{}::", part.data.as_interned_str()).unwrap(); |
| } else { |
| write!(output, "{}[{}]::", |
| part.data.as_interned_str(), |
| part.disambiguator).unwrap(); |
| } |
| } |
| |
| // remove final "::" |
| output.pop(); |
| output.pop(); |
| } |
| |
| fn push_type_params<I>(&self, |
| substs: &Substs<'tcx>, |
| projections: I, |
| output: &mut String) |
| where I: Iterator<Item=ty::PolyExistentialProjection<'tcx>> |
| { |
| let mut projections = projections.peekable(); |
| if substs.types().next().is_none() && projections.peek().is_none() { |
| return; |
| } |
| |
| output.push('<'); |
| |
| for type_parameter in substs.types() { |
| self.push_type_name(type_parameter, output); |
| output.push_str(", "); |
| } |
| |
| for projection in projections { |
| let projection = projection.skip_binder(); |
| let name = &self.tcx.associated_item(projection.item_def_id).name.as_str(); |
| output.push_str(name); |
| output.push_str("="); |
| self.push_type_name(projection.ty, output); |
| output.push_str(", "); |
| } |
| |
| output.pop(); |
| output.pop(); |
| |
| output.push('>'); |
| } |
| |
| pub fn push_instance_as_string(&self, |
| instance: Instance<'tcx>, |
| output: &mut String) { |
| self.push_def_path(instance.def_id(), output); |
| self.push_type_params(instance.substs, iter::empty(), output); |
| } |
| } |
