use crate::hir::def_id::{DefId, CrateNum, LOCAL_CRATE};
use crate::hir::HirId;
use syntax::symbol::InternedString;
-use crate::ty::{Instance, TyCtxt};
+use syntax::attr::InlineAttr;
+use syntax::source_map::Span;
+use crate::ty::{Instance, InstanceDef, TyCtxt, SymbolName, subst::InternalSubsts};
use crate::util::nodemap::FxHashMap;
+use crate::ty::print::obsolete::DefPathBasedNames;
+use crate::dep_graph::{WorkProductId, DepNode, WorkProduct, DepConstructor};
use rustc_data_structures::base_n;
use rustc_data_structures::stable_hasher::{HashStable, StableHasherResult,
StableHasher};
use crate::ich::{Fingerprint, StableHashingContext, NodeIdHashingMode};
+use crate::session::config::OptLevel;
use std::fmt;
use std::hash::Hash;
+/// 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,
+}
+
#[derive(PartialEq, Eq, Clone, Copy, Debug, Hash)]
pub enum MonoItem<'tcx> {
Fn(Instance<'tcx>),
}
impl<'tcx> MonoItem<'tcx> {
- pub fn size_estimate<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> usize {
+ pub fn size_estimate(&self, tcx: TyCtxt<'tcx, 'tcx>) -> usize {
match *self {
MonoItem::Fn(instance) => {
// Estimate the size of a function based on how many statements
MonoItem::GlobalAsm(_) => 1,
}
}
+
+ pub fn is_generic_fn(&self) -> bool {
+ match *self {
+ MonoItem::Fn(ref instance) => {
+ instance.substs.non_erasable_generics().next().is_some()
+ }
+ MonoItem::Static(..) |
+ MonoItem::GlobalAsm(..) => false,
+ }
+ }
+
+ pub fn symbol_name(&self, tcx: TyCtxt<'tcx, 'tcx>) -> SymbolName {
+ match *self {
+ 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_from_hir_id(hir_id);
+ SymbolName {
+ name: InternedString::intern(&format!("global_asm_{:?}", def_id))
+ }
+ }
+ }
+ }
+
+ pub fn instantiation_mode(&self, tcx: TyCtxt<'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
+ }) && !tcx.sess.opts.cg.link_dead_code;
+
+ match *self {
+ 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 }
+ }
+ }
+ }
+
+ pub fn explicit_linkage(&self, tcx: TyCtxt<'tcx, 'tcx>) -> Option<Linkage> {
+ let def_id = match *self {
+ 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.
+ pub fn is_instantiable(&self, tcx: TyCtxt<'tcx, 'tcx>) -> bool {
+ debug!("is_instantiable({:?})", self);
+ let (def_id, substs) = match *self {
+ 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))
+ }
+
+ pub fn to_string(&self, tcx: TyCtxt<'tcx, 'tcx>, debug: bool) -> String {
+ return match *self {
+ 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<'tcx>(
+ tcx: TyCtxt<'tcx, '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
+ }
+ }
+
+ pub fn local_span(&self, tcx: TyCtxt<'tcx, 'tcx>) -> Option<Span> {
+ match *self {
+ 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_by_hir_id(hir_id))
+ }
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for MonoItem<'tcx> {
base_n::encode(hash, base_n::CASE_INSENSITIVE)
}
- pub fn estimate_size<'a>(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>) {
+ pub fn estimate_size(&mut self, tcx: TyCtxt<'tcx, 'tcx>) {
// Estimate the size of a codegen unit as (approximately) the number of MIR
// statements it corresponds to.
self.size_estimate = Some(self.items.keys().map(|mi| mi.size_estimate(tcx)).sum());
self.size_estimate = Some(size_estimate + delta);
}
}
+
+ pub fn contains_item(&self, item: &MonoItem<'tcx>) -> bool {
+ self.items().contains_key(item)
+ }
+
+ pub fn work_product_id(&self) -> WorkProductId {
+ WorkProductId::from_cgu_name(&self.name().as_str())
+ }
+
+ pub fn work_product(&self, tcx: TyCtxt<'_, '_>) -> WorkProduct {
+ let work_product_id = self.work_product_id();
+ tcx.dep_graph
+ .previous_work_product(&work_product_id)
+ .unwrap_or_else(|| {
+ panic!("Could not find work-product for CGU `{}`", self.name())
+ })
+ }
+
+ pub fn items_in_deterministic_order(
+ &self,
+ tcx: TyCtxt<'tcx, 'tcx>,
+ ) -> Vec<(MonoItem<'tcx>, (Linkage, Visibility))> {
+ // The codegen tests rely on items being process in the same order as
+ // they appear in the file, so for local items, we sort by node_id first
+ #[derive(PartialEq, Eq, PartialOrd, Ord)]
+ pub struct ItemSortKey(Option<HirId>, SymbolName);
+
+ fn item_sort_key<'tcx>(tcx: TyCtxt<'tcx, 'tcx>, item: MonoItem<'tcx>) -> ItemSortKey {
+ ItemSortKey(match item {
+ MonoItem::Fn(ref instance) => {
+ match instance.def {
+ // We only want to take HirIds of user-defined
+ // instances into account. The others don't matter for
+ // the codegen tests and can even make item order
+ // unstable.
+ InstanceDef::Item(def_id) => {
+ tcx.hir().as_local_hir_id(def_id)
+ }
+ InstanceDef::VtableShim(..) |
+ InstanceDef::Intrinsic(..) |
+ InstanceDef::FnPtrShim(..) |
+ InstanceDef::Virtual(..) |
+ InstanceDef::ClosureOnceShim { .. } |
+ InstanceDef::DropGlue(..) |
+ InstanceDef::CloneShim(..) => {
+ None
+ }
+ }
+ }
+ MonoItem::Static(def_id) => {
+ tcx.hir().as_local_hir_id(def_id)
+ }
+ MonoItem::GlobalAsm(hir_id) => {
+ Some(hir_id)
+ }
+ }, item.symbol_name(tcx))
+ }
+
+ let mut items: Vec<_> = self.items().iter().map(|(&i, &l)| (i, l)).collect();
+ items.sort_by_cached_key(|&(i, _)| item_sort_key(tcx, i));
+ items
+ }
+
+ pub fn codegen_dep_node(&self, tcx: TyCtxt<'tcx, 'tcx>) -> DepNode {
+ DepNode::new(tcx, DepConstructor::CompileCodegenUnit(self.name().clone()))
+ }
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for CodegenUnit<'tcx> {
}
}
-pub struct CodegenUnitNameBuilder<'a, 'gcx: 'tcx, 'tcx: 'a> {
- tcx: TyCtxt<'a, 'gcx, 'tcx>,
+pub struct CodegenUnitNameBuilder<'gcx, 'tcx> {
+ tcx: TyCtxt<'gcx, 'tcx>,
cache: FxHashMap<CrateNum, String>,
}
-impl<'a, 'gcx: 'tcx, 'tcx: 'a> CodegenUnitNameBuilder<'a, 'gcx, 'tcx> {
-
- pub fn new(tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Self {
+impl CodegenUnitNameBuilder<'gcx, 'tcx> {
+ pub fn new(tcx: TyCtxt<'gcx, 'tcx>) -> Self {
CodegenUnitNameBuilder {
tcx,
cache: Default::default(),
projects / rust.git / blobdiff