From 7fa06f6b882bd0ee9366f31ccf4ae948a16494f9 Mon Sep 17 00:00:00 2001 From: bjorn3 <17426603+bjorn3@users.noreply.github.com> Date: Tue, 13 Dec 2022 17:26:17 +0100 Subject: [PATCH] Avoid a hir access inside get_static --- src/consts.rs | 133 ++++++++++++++++++++------------------------------ 1 file changed, 53 insertions(+), 80 deletions(-) diff --git a/src/consts.rs b/src/consts.rs index 9307d280f61..d70c9076897 100644 --- a/src/consts.rs +++ b/src/consts.rs @@ -2,9 +2,7 @@ use gccjit::FnAttribute; use gccjit::{Function, GlobalKind, LValue, RValue, ToRValue, Type}; use rustc_codegen_ssa::traits::{BaseTypeMethods, ConstMethods, DerivedTypeMethods, StaticMethods}; -use rustc_hir as hir; -use rustc_hir::Node; -use rustc_middle::{bug, span_bug}; +use rustc_middle::span_bug; use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; use rustc_middle::mir::mono::MonoItem; use rustc_middle::ty::{self, Instance, Ty}; @@ -217,84 +215,59 @@ pub fn get_static(&self, def_id: DefId) -> LValue<'gcc> { let ty = instance.ty(self.tcx, ty::ParamEnv::reveal_all()); let sym = self.tcx.symbol_name(instance).name; - let global = - if let Some(def_id) = def_id.as_local() { - let id = self.tcx.hir().local_def_id_to_hir_id(def_id); - let llty = self.layout_of(ty).gcc_type(self); - // FIXME: refactor this to work without accessing the HIR - let global = match self.tcx.hir().get(id) { - Node::Item(&hir::Item { span, kind: hir::ItemKind::Static(..), .. }) => { - if let Some(global) = self.get_declared_value(&sym) { - if self.val_ty(global) != self.type_ptr_to(llty) { - span_bug!(span, "Conflicting types for static"); - } - } - - let is_tls = fn_attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL); - let global = self.declare_global( - &sym, - llty, - GlobalKind::Exported, - is_tls, - fn_attrs.link_section, - ); - - if !self.tcx.is_reachable_non_generic(def_id) { - // TODO(antoyo): set visibility. - } - - global - } - - Node::ForeignItem(&hir::ForeignItem { - span, - kind: hir::ForeignItemKind::Static(..), - .. - }) => { - let fn_attrs = self.tcx.codegen_fn_attrs(def_id); - check_and_apply_linkage(&self, &fn_attrs, ty, sym, span) - } - - item => bug!("get_static: expected static, found {:?}", item), - }; - - global - } - else { - // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow? - //debug!("get_static: sym={} item_attr={:?}", sym, self.tcx.item_attrs(def_id)); - - let attrs = self.tcx.codegen_fn_attrs(def_id); - let span = self.tcx.def_span(def_id); - let global = check_and_apply_linkage(&self, &attrs, ty, sym, span); - - let needs_dll_storage_attr = false; // TODO(antoyo) - - // If this assertion triggers, there's something wrong with commandline - // argument validation. - debug_assert!( - !(self.tcx.sess.opts.cg.linker_plugin_lto.enabled() - && self.tcx.sess.target.options.is_like_msvc - && self.tcx.sess.opts.cg.prefer_dynamic) - ); - - if needs_dll_storage_attr { - // This item is external but not foreign, i.e., it originates from an external Rust - // crate. Since we don't know whether this crate will be linked dynamically or - // statically in the final application, we always mark such symbols as 'dllimport'. - // If final linkage happens to be static, we rely on compiler-emitted __imp_ stubs - // to make things work. - // - // However, in some scenarios we defer emission of statics to downstream - // crates, so there are cases where a static with an upstream DefId - // is actually present in the current crate. We can find out via the - // is_codegened_item query. - if !self.tcx.is_codegened_item(def_id) { - unimplemented!(); - } + let global = if def_id.is_local() && !self.tcx.is_foreign_item(def_id) { + let llty = self.layout_of(ty).gcc_type(self); + if let Some(global) = self.get_declared_value(sym) { + if self.val_ty(global) != self.type_ptr_to(llty) { + span_bug!(self.tcx.def_span(def_id), "Conflicting types for static"); } - global - }; + } + + let is_tls = fn_attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL); + let global = self.declare_global( + &sym, + llty, + GlobalKind::Exported, + is_tls, + fn_attrs.link_section, + ); + + if !self.tcx.is_reachable_non_generic(def_id) { + // TODO(antoyo): set visibility. + } + + global + } else { + check_and_apply_linkage(&self, &fn_attrs, ty, sym, self.tcx.def_span(def_id)) + }; + + if !def_id.is_local() { + let needs_dll_storage_attr = false; // TODO(antoyo) + + // If this assertion triggers, there's something wrong with commandline + // argument validation. + debug_assert!( + !(self.tcx.sess.opts.cg.linker_plugin_lto.enabled() + && self.tcx.sess.target.options.is_like_msvc + && self.tcx.sess.opts.cg.prefer_dynamic) + ); + + if needs_dll_storage_attr { + // This item is external but not foreign, i.e., it originates from an external Rust + // crate. Since we don't know whether this crate will be linked dynamically or + // statically in the final application, we always mark such symbols as 'dllimport'. + // If final linkage happens to be static, we rely on compiler-emitted __imp_ stubs + // to make things work. + // + // However, in some scenarios we defer emission of statics to downstream + // crates, so there are cases where a static with an upstream DefId + // is actually present in the current crate. We can find out via the + // is_codegened_item query. + if !self.tcx.is_codegened_item(def_id) { + unimplemented!(); + } + } + } // TODO(antoyo): set dll storage class.