diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/consts.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/consts.rs | 261 |
1 files changed, 125 insertions, 136 deletions
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs index 5deddb3ed98..0b96b63bc85 100644 --- a/compiler/rustc_codegen_llvm/src/consts.rs +++ b/compiler/rustc_codegen_llvm/src/consts.rs @@ -17,13 +17,12 @@ use rustc_middle::ty::{self, Instance}; use rustc_middle::{bug, span_bug}; use tracing::{debug, instrument, trace}; -use crate::common::{AsCCharPtr, CodegenCx}; +use crate::common::CodegenCx; use crate::errors::SymbolAlreadyDefined; -use crate::llvm::{self, True}; use crate::type_::Type; use crate::type_of::LayoutLlvmExt; use crate::value::Value; -use crate::{base, debuginfo}; +use crate::{base, debuginfo, llvm}; pub(crate) fn const_alloc_to_llvm<'ll>( cx: &CodegenCx<'ll, '_>, @@ -247,7 +246,7 @@ impl<'ll> CodegenCx<'ll, '_> { }; llvm::set_initializer(gv, cv); set_global_alignment(self, gv, align); - llvm::SetUnnamedAddress(gv, llvm::UnnamedAddr::Global); + llvm::set_unnamed_address(gv, llvm::UnnamedAddr::Global); gv } @@ -272,9 +271,8 @@ impl<'ll> CodegenCx<'ll, '_> { return gv; } let gv = self.static_addr_of_mut(cv, align, kind); - unsafe { - llvm::LLVMSetGlobalConstant(gv, True); - } + llvm::set_global_constant(gv, true); + self.const_globals.borrow_mut().insert(cv, gv); gv } @@ -398,149 +396,140 @@ impl<'ll> CodegenCx<'ll, '_> { } fn codegen_static_item(&mut self, def_id: DefId) { - unsafe { - assert!( - llvm::LLVMGetInitializer( - self.instances.borrow().get(&Instance::mono(self.tcx, def_id)).unwrap() - ) - .is_none() - ); - let attrs = self.tcx.codegen_fn_attrs(def_id); + assert!( + llvm::LLVMGetInitializer( + self.instances.borrow().get(&Instance::mono(self.tcx, def_id)).unwrap() + ) + .is_none() + ); + let attrs = self.tcx.codegen_fn_attrs(def_id); - let Ok((v, alloc)) = codegen_static_initializer(self, def_id) else { - // Error has already been reported - return; - }; - let alloc = alloc.inner(); + let Ok((v, alloc)) = codegen_static_initializer(self, def_id) else { + // Error has already been reported + return; + }; + let alloc = alloc.inner(); - let val_llty = self.val_ty(v); + let val_llty = self.val_ty(v); - let g = self.get_static_inner(def_id, val_llty); - let llty = self.get_type_of_global(g); + let g = self.get_static_inner(def_id, val_llty); + let llty = self.get_type_of_global(g); - let g = if val_llty == llty { - g - } else { - // codegen_static_initializer creates the global value just from the - // `Allocation` data by generating one big struct value that is just - // all the bytes and pointers after each other. This will almost never - // match the type that the static was declared with. Unfortunately - // we can't just LLVMConstBitCast our way out of it because that has very - // specific rules on what can be cast. So instead of adding a new way to - // generate static initializers that match the static's type, we picked - // the easier option and retroactively change the type of the static item itself. - let name = llvm::get_value_name(g); - llvm::set_value_name(g, b""); - - let linkage = llvm::get_linkage(g); - let visibility = llvm::get_visibility(g); - - let new_g = llvm::LLVMRustGetOrInsertGlobal( - self.llmod, - name.as_c_char_ptr(), - name.len(), - val_llty, - ); - - llvm::set_linkage(new_g, linkage); - llvm::set_visibility(new_g, visibility); - - // The old global has had its name removed but is returned by - // get_static since it is in the instance cache. Provide an - // alternative lookup that points to the new global so that - // global_asm! can compute the correct mangled symbol name - // for the global. - self.renamed_statics.borrow_mut().insert(def_id, new_g); - - // To avoid breaking any invariants, we leave around the old - // global for the moment; we'll replace all references to it - // with the new global later. (See base::codegen_backend.) - self.statics_to_rauw.borrow_mut().push((g, new_g)); - new_g - }; - set_global_alignment(self, g, alloc.align); - llvm::set_initializer(g, v); - - self.assume_dso_local(g, true); - - // Forward the allocation's mutability (picked by the const interner) to LLVM. - if alloc.mutability.is_not() { - llvm::LLVMSetGlobalConstant(g, llvm::True); - } + let g = if val_llty == llty { + g + } else { + // codegen_static_initializer creates the global value just from the + // `Allocation` data by generating one big struct value that is just + // all the bytes and pointers after each other. This will almost never + // match the type that the static was declared with. Unfortunately + // we can't just LLVMConstBitCast our way out of it because that has very + // specific rules on what can be cast. So instead of adding a new way to + // generate static initializers that match the static's type, we picked + // the easier option and retroactively change the type of the static item itself. + let name = String::from_utf8(llvm::get_value_name(g)) + .expect("we declare our statics with a utf8-valid name"); + llvm::set_value_name(g, b""); + + let linkage = llvm::get_linkage(g); + let visibility = llvm::get_visibility(g); + + let new_g = self.declare_global(&name, val_llty); + + llvm::set_linkage(new_g, linkage); + llvm::set_visibility(new_g, visibility); + + // The old global has had its name removed but is returned by + // get_static since it is in the instance cache. Provide an + // alternative lookup that points to the new global so that + // global_asm! can compute the correct mangled symbol name + // for the global. + self.renamed_statics.borrow_mut().insert(def_id, new_g); + + // To avoid breaking any invariants, we leave around the old + // global for the moment; we'll replace all references to it + // with the new global later. (See base::codegen_backend.) + self.statics_to_rauw.borrow_mut().push((g, new_g)); + new_g + }; + set_global_alignment(self, g, alloc.align); + llvm::set_initializer(g, v); - debuginfo::build_global_var_di_node(self, def_id, g); + self.assume_dso_local(g, true); - if attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL) { - llvm::set_thread_local_mode(g, self.tls_model); - } + // Forward the allocation's mutability (picked by the const interner) to LLVM. + if alloc.mutability.is_not() { + llvm::set_global_constant(g, true); + } - // Wasm statics with custom link sections get special treatment as they - // go into custom sections of the wasm executable. The exception to this - // is the `.init_array` section which are treated specially by the wasm linker. - if self.tcx.sess.target.is_like_wasm - && attrs - .link_section - .map(|link_section| !link_section.as_str().starts_with(".init_array")) - .unwrap_or(true) - { - if let Some(section) = attrs.link_section { - let section = llvm::LLVMMDStringInContext2( - self.llcx, - section.as_str().as_c_char_ptr(), - section.as_str().len(), - ); - assert!(alloc.provenance().ptrs().is_empty()); - - // The `inspect` method is okay here because we checked for provenance, and - // because we are doing this access to inspect the final interpreter state (not - // as part of the interpreter execution). - let bytes = - alloc.inspect_with_uninit_and_ptr_outside_interpreter(0..alloc.len()); - let alloc = - llvm::LLVMMDStringInContext2(self.llcx, bytes.as_c_char_ptr(), bytes.len()); - let data = [section, alloc]; - let meta = llvm::LLVMMDNodeInContext2(self.llcx, data.as_ptr(), data.len()); - let val = self.get_metadata_value(meta); + debuginfo::build_global_var_di_node(self, def_id, g); + + if attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL) { + llvm::set_thread_local_mode(g, self.tls_model); + } + + // Wasm statics with custom link sections get special treatment as they + // go into custom sections of the wasm executable. The exception to this + // is the `.init_array` section which are treated specially by the wasm linker. + if self.tcx.sess.target.is_like_wasm + && attrs + .link_section + .map(|link_section| !link_section.as_str().starts_with(".init_array")) + .unwrap_or(true) + { + if let Some(section) = attrs.link_section { + let section = self.create_metadata(section.as_str().as_bytes()); + assert!(alloc.provenance().ptrs().is_empty()); + + // The `inspect` method is okay here because we checked for provenance, and + // because we are doing this access to inspect the final interpreter state (not + // as part of the interpreter execution). + let bytes = alloc.inspect_with_uninit_and_ptr_outside_interpreter(0..alloc.len()); + let alloc = self.create_metadata(bytes); + let data = [section, alloc]; + let meta = + unsafe { llvm::LLVMMDNodeInContext2(self.llcx, data.as_ptr(), data.len()) }; + let val = self.get_metadata_value(meta); + unsafe { llvm::LLVMAddNamedMetadataOperand( self.llmod, c"wasm.custom_sections".as_ptr(), val, - ); - } - } else { - base::set_link_section(g, attrs); + ) + }; } + } else { + base::set_link_section(g, attrs); + } - base::set_variable_sanitizer_attrs(g, attrs); - - if attrs.flags.contains(CodegenFnAttrFlags::USED_COMPILER) { - // `USED` and `USED_LINKER` can't be used together. - assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)); - - // The semantics of #[used] in Rust only require the symbol to make it into the - // object file. It is explicitly allowed for the linker to strip the symbol if it - // is dead, which means we are allowed to use `llvm.compiler.used` instead of - // `llvm.used` here. - // - // Additionally, https://reviews.llvm.org/D97448 in LLVM 13 started emitting unique - // sections with SHF_GNU_RETAIN flag for llvm.used symbols, which may trigger bugs - // in the handling of `.init_array` (the static constructor list) in versions of - // the gold linker (prior to the one released with binutils 2.36). - // - // That said, we only ever emit these when `#[used(compiler)]` is explicitly - // requested. This is to avoid similar breakage on other targets, in particular - // MachO targets have *their* static constructor lists broken if `llvm.compiler.used` - // is emitted rather than `llvm.used`. However, that check happens when assigning - // the `CodegenFnAttrFlags` in the `codegen_fn_attrs` query, so we don't need to - // take care of it here. - self.add_compiler_used_global(g); - } - if attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER) { - // `USED` and `USED_LINKER` can't be used together. - assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED_COMPILER)); + base::set_variable_sanitizer_attrs(g, attrs); + + if attrs.flags.contains(CodegenFnAttrFlags::USED_COMPILER) { + // `USED` and `USED_LINKER` can't be used together. + assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)); + + // The semantics of #[used] in Rust only require the symbol to make it into the + // object file. It is explicitly allowed for the linker to strip the symbol if it + // is dead, which means we are allowed to use `llvm.compiler.used` instead of + // `llvm.used` here. + // + // Additionally, https://reviews.llvm.org/D97448 in LLVM 13 started emitting unique + // sections with SHF_GNU_RETAIN flag for llvm.used symbols, which may trigger bugs + // in the handling of `.init_array` (the static constructor list) in versions of + // the gold linker (prior to the one released with binutils 2.36). + // + // That said, we only ever emit these when `#[used(compiler)]` is explicitly + // requested. This is to avoid similar breakage on other targets, in particular + // MachO targets have *their* static constructor lists broken if `llvm.compiler.used` + // is emitted rather than `llvm.used`. However, that check happens when assigning + // the `CodegenFnAttrFlags` in the `codegen_fn_attrs` query, so we don't need to + // take care of it here. + self.add_compiler_used_global(g); + } + if attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER) { + // `USED` and `USED_LINKER` can't be used together. + assert!(!attrs.flags.contains(CodegenFnAttrFlags::USED_COMPILER)); - self.add_used_global(g); - } + self.add_used_global(g); } } |