From fbe109a2fc365087d778d2993cfa78cb2250475d Mon Sep 17 00:00:00 2001 From: bjorn3 Date: Tue, 2 Feb 2021 15:38:51 +0100 Subject: [PATCH] Avoid a hir access inside get_static --- compiler/rustc_codegen_llvm/src/consts.rs | 80 +++++++---------------- 1 file changed, 24 insertions(+), 56 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs index 14dd245625d25..80db614faf98c 100644 --- a/compiler/rustc_codegen_llvm/src/consts.rs +++ b/compiler/rustc_codegen_llvm/src/consts.rs @@ -8,9 +8,7 @@ use crate::value::Value; use libc::c_uint; use rustc_codegen_ssa::traits::*; use rustc_data_structures::const_cstr; -use rustc_hir as hir; use rustc_hir::def_id::DefId; -use rustc_hir::Node; use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; use rustc_middle::mir::interpret::{ read_target_uint, Allocation, ErrorHandled, GlobalAlloc, Pointer, @@ -18,7 +16,6 @@ use rustc_middle::mir::interpret::{ use rustc_middle::mir::mono::MonoItem; use rustc_middle::ty::{self, Instance, Ty}; use rustc_middle::{bug, span_bug}; -use rustc_span::symbol::sym; use rustc_target::abi::{AddressSpace, Align, HasDataLayout, LayoutOf, Primitive, Scalar, Size}; use tracing::debug; @@ -209,70 +206,42 @@ impl CodegenCx<'ll, 'tcx> { let ty = instance.ty(self.tcx, ty::ParamEnv::reveal_all()); let sym = self.tcx.symbol_name(instance).name; + let fn_attrs = self.tcx.codegen_fn_attrs(def_id); - debug!("get_static: sym={} instance={:?}", sym, instance); + debug!("get_static: sym={} instance={:?} fn_attrs={:?}", sym, instance, fn_attrs); - let g = if let Some(local_def_id) = def_id.as_local() { - let id = self.tcx.hir().local_def_id_to_hir_id(local_def_id); + let g = if def_id.as_local().is_some() && !self.tcx.is_foreign_item(def_id) { let llty = self.layout_of(ty).llvm_type(self); - // FIXME: refactor this to work without accessing the HIR - let (g, attrs) = match self.tcx.hir().get(id) { - Node::Item(&hir::Item { attrs, kind: hir::ItemKind::Static(..), .. }) => { - if let Some(g) = self.get_declared_value(sym) { - if self.val_ty(g) != self.type_ptr_to(llty) { - span_bug!(self.tcx.def_span(def_id), "Conflicting types for static"); - } - } - - let g = self.declare_global(sym, llty); - - if !self.tcx.is_reachable_non_generic(local_def_id) { - unsafe { - llvm::LLVMRustSetVisibility(g, llvm::Visibility::Hidden); - } - } - - (g, attrs) + if let Some(g) = self.get_declared_value(sym) { + if self.val_ty(g) != self.type_ptr_to(llty) { + span_bug!(self.tcx.def_span(def_id), "Conflicting types for static"); } + } - Node::ForeignItem(&hir::ForeignItem { - ref attrs, - kind: hir::ForeignItemKind::Static(..), - .. - }) => { - let fn_attrs = self.tcx.codegen_fn_attrs(local_def_id); - (check_and_apply_linkage(&self, &fn_attrs, ty, sym, def_id), &**attrs) - } - - item => bug!("get_static: expected static, found {:?}", item), - }; - - debug!("get_static: sym={} attrs={:?}", sym, attrs); + let g = self.declare_global(sym, llty); - for attr in attrs { - if self.tcx.sess.check_name(attr, sym::thread_local) { - llvm::set_thread_local_mode(g, self.tls_model); + if !self.tcx.is_reachable_non_generic(def_id) { + unsafe { + llvm::LLVMRustSetVisibility(g, llvm::Visibility::Hidden); } } g } 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)); + check_and_apply_linkage(&self, &fn_attrs, ty, sym, def_id) + }; - let attrs = self.tcx.codegen_fn_attrs(def_id); - let g = check_and_apply_linkage(&self, &attrs, ty, sym, def_id); - - // Thread-local statics in some other crate need to *always* be linked - // against in a thread-local fashion, so we need to be sure to apply the - // thread-local attribute locally if it was present remotely. If we - // don't do this then linker errors can be generated where the linker - // complains that one object files has a thread local version of the - // symbol and another one doesn't. - if attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL) { - llvm::set_thread_local_mode(g, self.tls_model); - } + // Thread-local statics in some other crate need to *always* be linked + // against in a thread-local fashion, so we need to be sure to apply the + // thread-local attribute locally if it was present remotely. If we + // don't do this then linker errors can be generated where the linker + // complains that one object files has a thread local version of the + // symbol and another one doesn't. + if fn_attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL) { + llvm::set_thread_local_mode(g, self.tls_model); + } + if def_id.as_local().is_none() { let needs_dll_storage_attr = self.use_dll_storage_attrs && !self.tcx.is_foreign_item(def_id) && // ThinLTO can't handle this workaround in all cases, so we don't // emit the attrs. Instead we make them unnecessary by disallowing @@ -304,8 +273,7 @@ impl CodegenCx<'ll, 'tcx> { } } } - g - }; + } if self.use_dll_storage_attrs && self.tcx.is_dllimport_foreign_item(def_id) { // For foreign (native) libs we know the exact storage type to use.