use self::type_map::DINodeCreationResult; use self::type_map::Stub; use self::type_map::UniqueTypeId; use super::namespace::mangled_name_of_instance; use super::type_names::{compute_debuginfo_type_name, compute_debuginfo_vtable_name}; use super::utils::{ create_DIArray, debug_context, get_namespace_for_item, is_node_local_to_unit, DIB, }; use super::CodegenUnitDebugContext; use crate::abi; use crate::common::CodegenCx; use crate::debuginfo::metadata::type_map::build_type_with_children; use crate::debuginfo::utils::fat_pointer_kind; use crate::debuginfo::utils::FatPtrKind; use crate::llvm; use crate::llvm::debuginfo::{ DIDescriptor, DIFile, DIFlags, DILexicalBlock, DIScope, DIType, DebugEmissionKind, }; use crate::value::Value; use cstr::cstr; use rustc_codegen_ssa::debuginfo::type_names::cpp_like_debuginfo; use rustc_codegen_ssa::debuginfo::type_names::VTableNameKind; use rustc_codegen_ssa::traits::*; use rustc_fs_util::path_to_c_string; use rustc_hir::def::CtorKind; use rustc_hir::def_id::{DefId, LOCAL_CRATE}; use rustc_index::vec::{Idx, IndexVec}; use rustc_middle::bug; use rustc_middle::mir::{self, GeneratorLayout}; use rustc_middle::ty::layout::{LayoutOf, TyAndLayout}; use rustc_middle::ty::subst::GenericArgKind; use rustc_middle::ty::{ self, AdtKind, Instance, ParamEnv, PolyExistentialTraitRef, Ty, TyCtxt, Visibility, }; use rustc_session::config::{self, DebugInfo, Lto}; use rustc_span::symbol::Symbol; use rustc_span::FileName; use rustc_span::{self, FileNameDisplayPreference, SourceFile}; use rustc_symbol_mangling::typeid_for_trait_ref; use rustc_target::abi::{Align, Size}; use smallvec::smallvec; use tracing::debug; use libc::{c_char, c_longlong, c_uint}; use std::borrow::Cow; use std::fmt::{self, Write}; use std::hash::{Hash, Hasher}; use std::iter; use std::path::{Path, PathBuf}; use std::ptr; use tracing::instrument; impl PartialEq for llvm::Metadata { fn eq(&self, other: &Self) -> bool { ptr::eq(self, other) } } impl Eq for llvm::Metadata {} impl Hash for llvm::Metadata { fn hash(&self, hasher: &mut H) { (self as *const Self).hash(hasher); } } impl fmt::Debug for llvm::Metadata { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { (self as *const Self).fmt(f) } } // From DWARF 5. // See http://www.dwarfstd.org/ShowIssue.php?issue=140129.1. const DW_LANG_RUST: c_uint = 0x1c; #[allow(non_upper_case_globals)] const DW_ATE_boolean: c_uint = 0x02; #[allow(non_upper_case_globals)] const DW_ATE_float: c_uint = 0x04; #[allow(non_upper_case_globals)] const DW_ATE_signed: c_uint = 0x05; #[allow(non_upper_case_globals)] const DW_ATE_unsigned: c_uint = 0x07; #[allow(non_upper_case_globals)] const DW_ATE_UTF: c_uint = 0x10; pub(super) const UNKNOWN_LINE_NUMBER: c_uint = 0; pub(super) const UNKNOWN_COLUMN_NUMBER: c_uint = 0; const NO_SCOPE_METADATA: Option<&DIScope> = None; /// A function that returns an empty list of generic parameter debuginfo nodes. const NO_GENERICS: for<'ll> fn(&CodegenCx<'ll, '_>) -> SmallVec<&'ll DIType> = |_| SmallVec::new(); // SmallVec is used quite a bit in this module, so create a shorthand. // The actual number of elements is not so important. pub type SmallVec = smallvec::SmallVec<[T; 16]>; mod enums; mod type_map; pub(crate) use type_map::TypeMap; /// Returns from the enclosing function if the type debuginfo node with the given /// unique ID can be found in the type map. macro_rules! return_if_di_node_created_in_meantime { ($cx: expr, $unique_type_id: expr) => { if let Some(di_node) = debug_context($cx).type_map.di_node_for_unique_id($unique_type_id) { return DINodeCreationResult::new(di_node, true); } }; } /// Extract size and alignment from a TyAndLayout. fn size_and_align_of<'tcx>(ty_and_layout: TyAndLayout<'tcx>) -> (Size, Align) { (ty_and_layout.size, ty_and_layout.align.abi) } /// Creates debuginfo for a fixed size array (e.g. `[u64; 123]`). /// For slices (that is, "arrays" of unknown size) use [build_slice_type_di_node]. fn build_fixed_size_array_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, unique_type_id: UniqueTypeId<'tcx>, array_type: Ty<'tcx>, ) -> DINodeCreationResult<'ll> { let ty::Array(element_type, len) = array_type.kind() else { bug!("build_fixed_size_array_di_node() called with non-ty::Array type `{:?}`", array_type) }; let element_type_di_node = type_di_node(cx, *element_type); return_if_di_node_created_in_meantime!(cx, unique_type_id); let (size, align) = cx.size_and_align_of(array_type); let upper_bound = len.eval_usize(cx.tcx, ty::ParamEnv::reveal_all()) as c_longlong; let subrange = unsafe { Some(llvm::LLVMRustDIBuilderGetOrCreateSubrange(DIB(cx), 0, upper_bound)) }; let subscripts = create_DIArray(DIB(cx), &[subrange]); let di_node = unsafe { llvm::LLVMRustDIBuilderCreateArrayType( DIB(cx), size.bits(), align.bits() as u32, element_type_di_node, subscripts, ) }; DINodeCreationResult::new(di_node, false) } /// Creates debuginfo for built-in pointer-like things: /// /// - ty::Ref /// - ty::RawPtr /// - ty::Adt in the case it's Box /// /// At some point we might want to remove the special handling of Box /// and treat it the same as other smart pointers (like Rc, Arc, ...). fn build_pointer_or_reference_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, ptr_type: Ty<'tcx>, pointee_type: Ty<'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { // The debuginfo generated by this function is only valid if `ptr_type` is really just // a (fat) pointer. Make sure it is not called for e.g. `Box`. debug_assert_eq!( cx.size_and_align_of(ptr_type), cx.size_and_align_of(cx.tcx.mk_mut_ptr(pointee_type)) ); let pointee_type_di_node = type_di_node(cx, pointee_type); return_if_di_node_created_in_meantime!(cx, unique_type_id); let (thin_pointer_size, thin_pointer_align) = cx.size_and_align_of(cx.tcx.mk_imm_ptr(cx.tcx.types.unit)); let ptr_type_debuginfo_name = compute_debuginfo_type_name(cx.tcx, ptr_type, true); match fat_pointer_kind(cx, pointee_type) { None => { // This is a thin pointer. Create a regular pointer type and give it the correct name. debug_assert_eq!( (thin_pointer_size, thin_pointer_align), cx.size_and_align_of(ptr_type), "ptr_type={}, pointee_type={}", ptr_type, pointee_type, ); let di_node = unsafe { llvm::LLVMRustDIBuilderCreatePointerType( DIB(cx), pointee_type_di_node, thin_pointer_size.bits(), thin_pointer_align.bits() as u32, 0, // Ignore DWARF address space. ptr_type_debuginfo_name.as_ptr().cast(), ptr_type_debuginfo_name.len(), ) }; DINodeCreationResult { di_node, already_stored_in_typemap: false } } Some(fat_pointer_kind) => { type_map::build_type_with_children( cx, type_map::stub( cx, Stub::Struct, unique_type_id, &ptr_type_debuginfo_name, cx.size_and_align_of(ptr_type), NO_SCOPE_METADATA, DIFlags::FlagZero, ), |cx, owner| { // FIXME: If this fat pointer is a `Box` then we don't want to use its // type layout and instead use the layout of the raw pointer inside // of it. // The proper way to handle this is to not treat Box as a pointer // at all and instead emit regular struct debuginfo for it. We just // need to make sure that we don't break existing debuginfo consumers // by doing that (at least not without a warning period). let layout_type = if ptr_type.is_box() { cx.tcx.mk_mut_ptr(pointee_type) } else { ptr_type }; let layout = cx.layout_of(layout_type); let addr_field = layout.field(cx, abi::FAT_PTR_ADDR); let extra_field = layout.field(cx, abi::FAT_PTR_EXTRA); let (addr_field_name, extra_field_name) = match fat_pointer_kind { FatPtrKind::Dyn => ("pointer", "vtable"), FatPtrKind::Slice => ("data_ptr", "length"), }; debug_assert_eq!(abi::FAT_PTR_ADDR, 0); debug_assert_eq!(abi::FAT_PTR_EXTRA, 1); // The data pointer type is a regular, thin pointer, regardless of whether this // is a slice or a trait object. let data_ptr_type_di_node = unsafe { llvm::LLVMRustDIBuilderCreatePointerType( DIB(cx), pointee_type_di_node, addr_field.size.bits(), addr_field.align.abi.bits() as u32, 0, // Ignore DWARF address space. std::ptr::null(), 0, ) }; smallvec![ build_field_di_node( cx, owner, addr_field_name, (addr_field.size, addr_field.align.abi), layout.fields.offset(abi::FAT_PTR_ADDR), DIFlags::FlagZero, data_ptr_type_di_node, ), build_field_di_node( cx, owner, extra_field_name, (extra_field.size, extra_field.align.abi), layout.fields.offset(abi::FAT_PTR_EXTRA), DIFlags::FlagZero, type_di_node(cx, extra_field.ty), ), ] }, NO_GENERICS, ) } } } fn build_subroutine_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { // It's possible to create a self-referential // type in Rust by using 'impl trait': // // fn foo() -> impl Copy { foo } // // Unfortunately LLVM's API does not allow us to create recursive subroutine types. // In order to work around that restriction we place a marker type in the type map, // before creating the actual type. If the actual type is recursive, it will hit the // marker type. So we end up with a type that looks like // // fn foo() -> // // Once that is created, we replace the marker in the typemap with the actual type. debug_context(cx) .type_map .unique_id_to_di_node .borrow_mut() .insert(unique_type_id, recursion_marker_type_di_node(cx)); let fn_ty = unique_type_id.expect_ty(); let signature = cx .tcx .normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), fn_ty.fn_sig(cx.tcx)); let signature_di_nodes: SmallVec<_> = iter::once( // return type match signature.output().kind() { ty::Tuple(tys) if tys.is_empty() => { // this is a "void" function None } _ => Some(type_di_node(cx, signature.output())), }, ) .chain( // regular arguments signature.inputs().iter().map(|&argument_type| Some(type_di_node(cx, argument_type))), ) .collect(); debug_context(cx).type_map.unique_id_to_di_node.borrow_mut().remove(&unique_type_id); let fn_di_node = unsafe { llvm::LLVMRustDIBuilderCreateSubroutineType( DIB(cx), create_DIArray(DIB(cx), &signature_di_nodes[..]), ) }; // This is actually a function pointer, so wrap it in pointer DI. let name = compute_debuginfo_type_name(cx.tcx, fn_ty, false); let di_node = unsafe { llvm::LLVMRustDIBuilderCreatePointerType( DIB(cx), fn_di_node, cx.tcx.data_layout.pointer_size.bits(), cx.tcx.data_layout.pointer_align.abi.bits() as u32, 0, // Ignore DWARF address space. name.as_ptr().cast(), name.len(), ) }; DINodeCreationResult::new(di_node, false) } /// Create debuginfo for `dyn SomeTrait` types. Currently these are empty structs /// we with the correct type name (e.g. "dyn SomeTrait + Sync"). fn build_dyn_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, dyn_type: Ty<'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { if let ty::Dynamic(..) = dyn_type.kind() { let type_name = compute_debuginfo_type_name(cx.tcx, dyn_type, true); type_map::build_type_with_children( cx, type_map::stub( cx, Stub::Struct, unique_type_id, &type_name, cx.size_and_align_of(dyn_type), NO_SCOPE_METADATA, DIFlags::FlagZero, ), |_, _| smallvec![], NO_GENERICS, ) } else { bug!( "Only ty::Dynamic is valid for build_dyn_type_di_node(). Found {:?} instead.", dyn_type ) } } /// Create debuginfo for `[T]` and `str`. These are unsized. /// /// NOTE: We currently emit just emit the debuginfo for the element type here /// (i.e. `T` for slices and `u8` for `str`), so that we end up with /// `*const T` for the `data_ptr` field of the corresponding fat-pointer /// debuginfo of `&[T]`. /// /// It would be preferable and more accurate if we emitted a DIArray of T /// without an upper bound instead. That is, LLVM already supports emitting /// debuginfo of arrays of unknown size. But GDB currently seems to end up /// in an infinite loop when confronted with such a type. /// /// As a side effect of the current encoding every instance of a type like /// `struct Foo { unsized_field: [u8] }` will look like /// `struct Foo { unsized_field: u8 }` in debuginfo. If the length of the /// slice is zero, then accessing `unsized_field` in the debugger would /// result in an out-of-bounds access. fn build_slice_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, slice_type: Ty<'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { let element_type = match slice_type.kind() { ty::Slice(element_type) => *element_type, ty::Str => cx.tcx.types.u8, _ => { bug!( "Only ty::Slice is valid for build_slice_type_di_node(). Found {:?} instead.", slice_type ) } }; let element_type_di_node = type_di_node(cx, element_type); return_if_di_node_created_in_meantime!(cx, unique_type_id); DINodeCreationResult { di_node: element_type_di_node, already_stored_in_typemap: false } } /// Get the debuginfo node for the given type. /// /// This function will look up the debuginfo node in the TypeMap. If it can't find it, it /// will create the node by dispatching to the corresponding `build_*_di_node()` function. pub fn type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll DIType { let unique_type_id = UniqueTypeId::for_ty(cx.tcx, t); if let Some(existing_di_node) = debug_context(cx).type_map.di_node_for_unique_id(unique_type_id) { return existing_di_node; } debug!("type_di_node: {:?}", t); let DINodeCreationResult { di_node, already_stored_in_typemap } = match *t.kind() { ty::Never | ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) => { build_basic_type_di_node(cx, t) } ty::Tuple(elements) if elements.is_empty() => build_basic_type_di_node(cx, t), ty::Array(..) => build_fixed_size_array_di_node(cx, unique_type_id, t), ty::Slice(_) | ty::Str => build_slice_type_di_node(cx, t, unique_type_id), ty::Dynamic(..) => build_dyn_type_di_node(cx, t, unique_type_id), ty::Foreign(..) => build_foreign_type_di_node(cx, t, unique_type_id), ty::RawPtr(ty::TypeAndMut { ty: pointee_type, .. }) | ty::Ref(_, pointee_type, _) => { build_pointer_or_reference_di_node(cx, t, pointee_type, unique_type_id) } // Box may have a non-ZST allocator A. In that case, we // cannot treat Box as just an owned alias of `*mut T`. ty::Adt(def, substs) if def.is_box() && cx.layout_of(substs.type_at(1)).is_zst() => { build_pointer_or_reference_di_node(cx, t, t.boxed_ty(), unique_type_id) } ty::FnDef(..) | ty::FnPtr(_) => build_subroutine_type_di_node(cx, unique_type_id), ty::Closure(..) => build_closure_env_di_node(cx, unique_type_id), ty::Generator(..) => enums::build_generator_di_node(cx, unique_type_id), ty::Adt(def, ..) => match def.adt_kind() { AdtKind::Struct => build_struct_type_di_node(cx, unique_type_id), AdtKind::Union => build_union_type_di_node(cx, unique_type_id), AdtKind::Enum => enums::build_enum_type_di_node(cx, unique_type_id), }, ty::Tuple(_) => build_tuple_type_di_node(cx, unique_type_id), // Type parameters from polymorphized functions. ty::Param(_) => build_param_type_di_node(cx, t), _ => bug!("debuginfo: unexpected type in type_di_node(): {:?}", t), }; { if already_stored_in_typemap { // Make sure that we really do have a `TypeMap` entry for the unique type ID. let di_node_for_uid = match debug_context(cx).type_map.di_node_for_unique_id(unique_type_id) { Some(di_node) => di_node, None => { bug!( "expected type debuginfo node for unique \ type ID '{:?}' to already be in \ the `debuginfo::TypeMap` but it \ was not.", unique_type_id, ); } }; debug_assert_eq!(di_node_for_uid as *const _, di_node as *const _); } else { debug_context(cx).type_map.insert(unique_type_id, di_node); } } di_node } // FIXME(mw): Cache this via a regular UniqueTypeId instead of an extra field in the debug context. fn recursion_marker_type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>) -> &'ll DIType { *debug_context(cx).recursion_marker_type.get_or_init(move || { unsafe { // The choice of type here is pretty arbitrary - // anything reading the debuginfo for a recursive // type is going to see *something* weird - the only // question is what exactly it will see. // // FIXME: the name `` does not fit the naming scheme // of other types. // // FIXME: it might make sense to use an actual pointer type here // so that debuggers can show the address. let name = ""; llvm::LLVMRustDIBuilderCreateBasicType( DIB(cx), name.as_ptr().cast(), name.len(), cx.tcx.data_layout.pointer_size.bits(), DW_ATE_unsigned, ) } }) } fn hex_encode(data: &[u8]) -> String { let mut hex_string = String::with_capacity(data.len() * 2); for byte in data.iter() { write!(&mut hex_string, "{:02x}", byte).unwrap(); } hex_string } pub fn file_metadata<'ll>(cx: &CodegenCx<'ll, '_>, source_file: &SourceFile) -> &'ll DIFile { let cache_key = Some((source_file.name_hash, source_file.src_hash)); return debug_context(cx) .created_files .borrow_mut() .entry(cache_key) .or_insert_with(|| alloc_new_file_metadata(cx, source_file)); #[instrument(skip(cx, source_file), level = "debug")] fn alloc_new_file_metadata<'ll>( cx: &CodegenCx<'ll, '_>, source_file: &SourceFile, ) -> &'ll DIFile { debug!(?source_file.name); let (directory, file_name) = match &source_file.name { FileName::Real(filename) => { let working_directory = &cx.sess().opts.working_dir; debug!(?working_directory); let filename = cx .sess() .source_map() .path_mapping() .to_embeddable_absolute_path(filename.clone(), working_directory); // Construct the absolute path of the file let abs_path = filename.remapped_path_if_available(); debug!(?abs_path); if let Ok(rel_path) = abs_path.strip_prefix(working_directory.remapped_path_if_available()) { // If the compiler's working directory (which also is the DW_AT_comp_dir of // the compilation unit) is a prefix of the path we are about to emit, then // only emit the part relative to the working directory. // Because of path remapping we sometimes see strange things here: `abs_path` // might actually look like a relative path // (e.g. `/src/lib.rs`), so if we emit it without // taking the working directory into account, downstream tooling will // interpret it as `//src/lib.rs`, // which makes no sense. Usually in such cases the working directory will also // be remapped to `` or some other prefix of the path // we are remapping, so we end up with // `//src/lib.rs`. // By moving the working directory portion into the `directory` part of the // DIFile, we allow LLVM to emit just the relative path for DWARF, while // still emitting the correct absolute path for CodeView. ( working_directory.to_string_lossy(FileNameDisplayPreference::Remapped), rel_path.to_string_lossy().into_owned(), ) } else { ("".into(), abs_path.to_string_lossy().into_owned()) } } other => ("".into(), other.prefer_remapped().to_string_lossy().into_owned()), }; let hash_kind = match source_file.src_hash.kind { rustc_span::SourceFileHashAlgorithm::Md5 => llvm::ChecksumKind::MD5, rustc_span::SourceFileHashAlgorithm::Sha1 => llvm::ChecksumKind::SHA1, rustc_span::SourceFileHashAlgorithm::Sha256 => llvm::ChecksumKind::SHA256, }; let hash_value = hex_encode(source_file.src_hash.hash_bytes()); unsafe { llvm::LLVMRustDIBuilderCreateFile( DIB(cx), file_name.as_ptr().cast(), file_name.len(), directory.as_ptr().cast(), directory.len(), hash_kind, hash_value.as_ptr().cast(), hash_value.len(), ) } } } pub fn unknown_file_metadata<'ll>(cx: &CodegenCx<'ll, '_>) -> &'ll DIFile { debug_context(cx).created_files.borrow_mut().entry(None).or_insert_with(|| unsafe { let file_name = ""; let directory = ""; let hash_value = ""; llvm::LLVMRustDIBuilderCreateFile( DIB(cx), file_name.as_ptr().cast(), file_name.len(), directory.as_ptr().cast(), directory.len(), llvm::ChecksumKind::None, hash_value.as_ptr().cast(), hash_value.len(), ) }) } trait MsvcBasicName { fn msvc_basic_name(self) -> &'static str; } impl MsvcBasicName for ty::IntTy { fn msvc_basic_name(self) -> &'static str { match self { ty::IntTy::Isize => "ptrdiff_t", ty::IntTy::I8 => "__int8", ty::IntTy::I16 => "__int16", ty::IntTy::I32 => "__int32", ty::IntTy::I64 => "__int64", ty::IntTy::I128 => "__int128", } } } impl MsvcBasicName for ty::UintTy { fn msvc_basic_name(self) -> &'static str { match self { ty::UintTy::Usize => "size_t", ty::UintTy::U8 => "unsigned __int8", ty::UintTy::U16 => "unsigned __int16", ty::UintTy::U32 => "unsigned __int32", ty::UintTy::U64 => "unsigned __int64", ty::UintTy::U128 => "unsigned __int128", } } } impl MsvcBasicName for ty::FloatTy { fn msvc_basic_name(self) -> &'static str { match self { ty::FloatTy::F32 => "float", ty::FloatTy::F64 => "double", } } } fn build_basic_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>, ) -> DINodeCreationResult<'ll> { debug!("build_basic_type_di_node: {:?}", t); // When targeting MSVC, emit MSVC style type names for compatibility with // .natvis visualizers (and perhaps other existing native debuggers?) let cpp_like_debuginfo = cpp_like_debuginfo(cx.tcx); let (name, encoding) = match t.kind() { ty::Never => ("!", DW_ATE_unsigned), ty::Tuple(elements) if elements.is_empty() => { if cpp_like_debuginfo { return build_tuple_type_di_node(cx, UniqueTypeId::for_ty(cx.tcx, t)); } else { ("()", DW_ATE_unsigned) } } ty::Bool => ("bool", DW_ATE_boolean), ty::Char => ("char", DW_ATE_UTF), ty::Int(int_ty) if cpp_like_debuginfo => (int_ty.msvc_basic_name(), DW_ATE_signed), ty::Uint(uint_ty) if cpp_like_debuginfo => (uint_ty.msvc_basic_name(), DW_ATE_unsigned), ty::Float(float_ty) if cpp_like_debuginfo => (float_ty.msvc_basic_name(), DW_ATE_float), ty::Int(int_ty) => (int_ty.name_str(), DW_ATE_signed), ty::Uint(uint_ty) => (uint_ty.name_str(), DW_ATE_unsigned), ty::Float(float_ty) => (float_ty.name_str(), DW_ATE_float), _ => bug!("debuginfo::build_basic_type_di_node - `t` is invalid type"), }; let ty_di_node = unsafe { llvm::LLVMRustDIBuilderCreateBasicType( DIB(cx), name.as_ptr().cast(), name.len(), cx.size_of(t).bits(), encoding, ) }; if !cpp_like_debuginfo { return DINodeCreationResult::new(ty_di_node, false); } let typedef_name = match t.kind() { ty::Int(int_ty) => int_ty.name_str(), ty::Uint(uint_ty) => uint_ty.name_str(), ty::Float(float_ty) => float_ty.name_str(), _ => return DINodeCreationResult::new(ty_di_node, false), }; let typedef_di_node = unsafe { llvm::LLVMRustDIBuilderCreateTypedef( DIB(cx), ty_di_node, typedef_name.as_ptr().cast(), typedef_name.len(), unknown_file_metadata(cx), 0, None, ) }; DINodeCreationResult::new(typedef_di_node, false) } fn build_foreign_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { debug!("build_foreign_type_di_node: {:?}", t); let &ty::Foreign(def_id) = unique_type_id.expect_ty().kind() else { bug!("build_foreign_type_di_node() called with unexpected type: {:?}", unique_type_id.expect_ty()); }; build_type_with_children( cx, type_map::stub( cx, Stub::Struct, unique_type_id, &compute_debuginfo_type_name(cx.tcx, t, false), cx.size_and_align_of(t), Some(get_namespace_for_item(cx, def_id)), DIFlags::FlagZero, ), |_, _| smallvec![], NO_GENERICS, ) } fn build_param_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>, ) -> DINodeCreationResult<'ll> { debug!("build_param_type_di_node: {:?}", t); let name = format!("{:?}", t); DINodeCreationResult { di_node: unsafe { llvm::LLVMRustDIBuilderCreateBasicType( DIB(cx), name.as_ptr().cast(), name.len(), Size::ZERO.bits(), DW_ATE_unsigned, ) }, already_stored_in_typemap: false, } } pub fn build_compile_unit_di_node<'ll, 'tcx>( tcx: TyCtxt<'tcx>, codegen_unit_name: &str, debug_context: &CodegenUnitDebugContext<'ll, 'tcx>, ) -> &'ll DIDescriptor { let mut name_in_debuginfo = match tcx.sess.local_crate_source_file { Some(ref path) => path.clone(), None => PathBuf::from(tcx.crate_name(LOCAL_CRATE).as_str()), }; // To avoid breaking split DWARF, we need to ensure that each codegen unit // has a unique `DW_AT_name`. This is because there's a remote chance that // different codegen units for the same module will have entirely // identical DWARF entries for the purpose of the DWO ID, which would // violate Appendix F ("Split Dwarf Object Files") of the DWARF 5 // specification. LLVM uses the algorithm specified in section 7.32 "Type // Signature Computation" to compute the DWO ID, which does not include // any fields that would distinguish compilation units. So we must embed // the codegen unit name into the `DW_AT_name`. (Issue #88521.) // // Additionally, the OSX linker has an idiosyncrasy where it will ignore // some debuginfo if multiple object files with the same `DW_AT_name` are // linked together. // // As a workaround for these two issues, we generate unique names for each // object file. Those do not correspond to an actual source file but that // is harmless. name_in_debuginfo.push("@"); name_in_debuginfo.push(codegen_unit_name); debug!("build_compile_unit_di_node: {:?}", name_in_debuginfo); let rustc_producer = format!("rustc version {}", option_env!("CFG_VERSION").expect("CFG_VERSION"),); // FIXME(#41252) Remove "clang LLVM" if we can get GDB and LLVM to play nice. let producer = format!("clang LLVM ({})", rustc_producer); let name_in_debuginfo = name_in_debuginfo.to_string_lossy(); let work_dir = tcx.sess.opts.working_dir.to_string_lossy(FileNameDisplayPreference::Remapped); let flags = "\0"; let output_filenames = tcx.output_filenames(()); let split_name = if tcx.sess.target_can_use_split_dwarf() { output_filenames .split_dwarf_path( tcx.sess.split_debuginfo(), tcx.sess.opts.unstable_opts.split_dwarf_kind, Some(codegen_unit_name), ) // We get a path relative to the working directory from split_dwarf_path .map(|f| tcx.sess.source_map().path_mapping().map_prefix(f).0) } else { None } .unwrap_or_default(); let split_name = split_name.to_str().unwrap(); // FIXME(#60020): // // This should actually be // // let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo); // // That is, we should set LLVM's emission kind to `LineTablesOnly` if // we are compiling with "limited" debuginfo. However, some of the // existing tools relied on slightly more debuginfo being generated than // would be the case with `LineTablesOnly`, and we did not want to break // these tools in a "drive-by fix", without a good idea or plan about // what limited debuginfo should exactly look like. So for now we keep // the emission kind as `FullDebug`. // // See https://github.com/rust-lang/rust/issues/60020 for details. let kind = DebugEmissionKind::FullDebug; assert!(tcx.sess.opts.debuginfo != DebugInfo::None); unsafe { let compile_unit_file = llvm::LLVMRustDIBuilderCreateFile( debug_context.builder, name_in_debuginfo.as_ptr().cast(), name_in_debuginfo.len(), work_dir.as_ptr().cast(), work_dir.len(), llvm::ChecksumKind::None, ptr::null(), 0, ); let unit_metadata = llvm::LLVMRustDIBuilderCreateCompileUnit( debug_context.builder, DW_LANG_RUST, compile_unit_file, producer.as_ptr().cast(), producer.len(), tcx.sess.opts.optimize != config::OptLevel::No, flags.as_ptr().cast(), 0, // NB: this doesn't actually have any perceptible effect, it seems. LLVM will instead // put the path supplied to `MCSplitDwarfFile` into the debug info of the final // output(s). split_name.as_ptr().cast(), split_name.len(), kind, 0, tcx.sess.opts.unstable_opts.split_dwarf_inlining, ); if tcx.sess.opts.unstable_opts.profile { let cu_desc_metadata = llvm::LLVMRustMetadataAsValue(debug_context.llcontext, unit_metadata); let default_gcda_path = &output_filenames.with_extension("gcda"); let gcda_path = tcx.sess.opts.unstable_opts.profile_emit.as_ref().unwrap_or(default_gcda_path); let gcov_cu_info = [ path_to_mdstring(debug_context.llcontext, &output_filenames.with_extension("gcno")), path_to_mdstring(debug_context.llcontext, gcda_path), cu_desc_metadata, ]; let gcov_metadata = llvm::LLVMMDNodeInContext( debug_context.llcontext, gcov_cu_info.as_ptr(), gcov_cu_info.len() as c_uint, ); let llvm_gcov_ident = cstr!("llvm.gcov"); llvm::LLVMAddNamedMetadataOperand( debug_context.llmod, llvm_gcov_ident.as_ptr(), gcov_metadata, ); } // Insert `llvm.ident` metadata on the wasm targets since that will // get hooked up to the "producer" sections `processed-by` information. if tcx.sess.target.is_like_wasm { let name_metadata = llvm::LLVMMDStringInContext( debug_context.llcontext, rustc_producer.as_ptr().cast(), rustc_producer.as_bytes().len() as c_uint, ); llvm::LLVMAddNamedMetadataOperand( debug_context.llmod, cstr!("llvm.ident").as_ptr(), llvm::LLVMMDNodeInContext(debug_context.llcontext, &name_metadata, 1), ); } return unit_metadata; }; fn path_to_mdstring<'ll>(llcx: &'ll llvm::Context, path: &Path) -> &'ll Value { let path_str = path_to_c_string(path); unsafe { llvm::LLVMMDStringInContext( llcx, path_str.as_ptr(), path_str.as_bytes().len() as c_uint, ) } } } /// Creates a `DW_TAG_member` entry inside the DIE represented by the given `type_di_node`. fn build_field_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, owner: &'ll DIScope, name: &str, size_and_align: (Size, Align), offset: Size, flags: DIFlags, type_di_node: &'ll DIType, ) -> &'ll DIType { unsafe { llvm::LLVMRustDIBuilderCreateMemberType( DIB(cx), owner, name.as_ptr().cast(), name.len(), unknown_file_metadata(cx), UNKNOWN_LINE_NUMBER, size_and_align.0.bits(), size_and_align.1.bits() as u32, offset.bits(), flags, type_di_node, ) } } /// Creates the debuginfo node for a Rust struct type. Maybe be a regular struct or a tuple-struct. fn build_struct_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { let struct_type = unique_type_id.expect_ty(); let ty::Adt(adt_def, _) = struct_type.kind() else { bug!("build_struct_type_di_node() called with non-struct-type: {:?}", struct_type); }; debug_assert!(adt_def.is_struct()); let containing_scope = get_namespace_for_item(cx, adt_def.did()); let struct_type_and_layout = cx.layout_of(struct_type); let variant_def = adt_def.non_enum_variant(); type_map::build_type_with_children( cx, type_map::stub( cx, Stub::Struct, unique_type_id, &compute_debuginfo_type_name(cx.tcx, struct_type, false), size_and_align_of(struct_type_and_layout), Some(containing_scope), DIFlags::FlagZero, ), // Fields: |cx, owner| { variant_def .fields .iter() .enumerate() .map(|(i, f)| { let field_name = if variant_def.ctor_kind == CtorKind::Fn { // This is a tuple struct tuple_field_name(i) } else { // This is struct with named fields Cow::Borrowed(f.name.as_str()) }; let field_layout = struct_type_and_layout.field(cx, i); build_field_di_node( cx, owner, &field_name[..], (field_layout.size, field_layout.align.abi), struct_type_and_layout.fields.offset(i), DIFlags::FlagZero, type_di_node(cx, field_layout.ty), ) }) .collect() }, |cx| build_generic_type_param_di_nodes(cx, struct_type), ) } //=----------------------------------------------------------------------------- // Tuples //=----------------------------------------------------------------------------- /// Returns names of captured upvars for closures and generators. /// /// Here are some examples: /// - `name__field1__field2` when the upvar is captured by value. /// - `_ref__name__field` when the upvar is captured by reference. /// /// For generators this only contains upvars that are shared by all states. fn closure_saved_names_of_captured_variables(tcx: TyCtxt<'_>, def_id: DefId) -> SmallVec { let body = tcx.optimized_mir(def_id); body.var_debug_info .iter() .filter_map(|var| { let is_ref = match var.value { mir::VarDebugInfoContents::Place(place) if place.local == mir::Local::new(1) => { // The projection is either `[.., Field, Deref]` or `[.., Field]`. It // implies whether the variable is captured by value or by reference. matches!(place.projection.last().unwrap(), mir::ProjectionElem::Deref) } _ => return None, }; let prefix = if is_ref { "_ref__" } else { "" }; Some(prefix.to_owned() + var.name.as_str()) }) .collect() } /// Builds the DW_TAG_member debuginfo nodes for the upvars of a closure or generator. /// For a generator, this will handle upvars shared by all states. fn build_upvar_field_di_nodes<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, closure_or_generator_ty: Ty<'tcx>, closure_or_generator_di_node: &'ll DIType, ) -> SmallVec<&'ll DIType> { let (&def_id, up_var_tys) = match closure_or_generator_ty.kind() { ty::Generator(def_id, substs, _) => { let upvar_tys: SmallVec<_> = substs.as_generator().prefix_tys().collect(); (def_id, upvar_tys) } ty::Closure(def_id, substs) => { let upvar_tys: SmallVec<_> = substs.as_closure().upvar_tys().collect(); (def_id, upvar_tys) } _ => { bug!( "build_upvar_field_di_nodes() called with non-closure-or-generator-type: {:?}", closure_or_generator_ty ) } }; debug_assert!( up_var_tys .iter() .all(|&t| t == cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), t)) ); let capture_names = closure_saved_names_of_captured_variables(cx.tcx, def_id); let layout = cx.layout_of(closure_or_generator_ty); up_var_tys .into_iter() .zip(capture_names.iter()) .enumerate() .map(|(index, (up_var_ty, capture_name))| { build_field_di_node( cx, closure_or_generator_di_node, capture_name, cx.size_and_align_of(up_var_ty), layout.fields.offset(index), DIFlags::FlagZero, type_di_node(cx, up_var_ty), ) }) .collect() } /// Builds the DW_TAG_structure_type debuginfo node for a Rust tuple type. fn build_tuple_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { let tuple_type = unique_type_id.expect_ty(); let &ty::Tuple(component_types) = tuple_type.kind() else { bug!("build_tuple_type_di_node() called with non-tuple-type: {:?}", tuple_type) }; let tuple_type_and_layout = cx.layout_of(tuple_type); let type_name = compute_debuginfo_type_name(cx.tcx, tuple_type, false); type_map::build_type_with_children( cx, type_map::stub( cx, Stub::Struct, unique_type_id, &type_name, size_and_align_of(tuple_type_and_layout), NO_SCOPE_METADATA, DIFlags::FlagZero, ), // Fields: |cx, tuple_di_node| { component_types .into_iter() .enumerate() .map(|(index, component_type)| { build_field_di_node( cx, tuple_di_node, &tuple_field_name(index), cx.size_and_align_of(component_type), tuple_type_and_layout.fields.offset(index), DIFlags::FlagZero, type_di_node(cx, component_type), ) }) .collect() }, NO_GENERICS, ) } /// Builds the debuginfo node for a closure environment. fn build_closure_env_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { let closure_env_type = unique_type_id.expect_ty(); let &ty::Closure(def_id, _substs) = closure_env_type.kind() else { bug!("build_closure_env_di_node() called with non-closure-type: {:?}", closure_env_type) }; let containing_scope = get_namespace_for_item(cx, def_id); let type_name = compute_debuginfo_type_name(cx.tcx, closure_env_type, false); type_map::build_type_with_children( cx, type_map::stub( cx, Stub::Struct, unique_type_id, &type_name, cx.size_and_align_of(closure_env_type), Some(containing_scope), DIFlags::FlagZero, ), // Fields: |cx, owner| build_upvar_field_di_nodes(cx, closure_env_type, owner), NO_GENERICS, ) } /// Build the debuginfo node for a Rust `union` type. fn build_union_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, unique_type_id: UniqueTypeId<'tcx>, ) -> DINodeCreationResult<'ll> { let union_type = unique_type_id.expect_ty(); let (union_def_id, variant_def) = match union_type.kind() { ty::Adt(def, _) => (def.did(), def.non_enum_variant()), _ => bug!("build_union_type_di_node on a non-ADT"), }; let containing_scope = get_namespace_for_item(cx, union_def_id); let union_ty_and_layout = cx.layout_of(union_type); let type_name = compute_debuginfo_type_name(cx.tcx, union_type, false); type_map::build_type_with_children( cx, type_map::stub( cx, Stub::Union, unique_type_id, &type_name, size_and_align_of(union_ty_and_layout), Some(containing_scope), DIFlags::FlagZero, ), // Fields: |cx, owner| { variant_def .fields .iter() .enumerate() .map(|(i, f)| { let field_layout = union_ty_and_layout.field(cx, i); build_field_di_node( cx, owner, f.name.as_str(), size_and_align_of(field_layout), Size::ZERO, DIFlags::FlagZero, type_di_node(cx, field_layout.ty), ) }) .collect() }, // Generics: |cx| build_generic_type_param_di_nodes(cx, union_type), ) } // FIXME(eddyb) maybe precompute this? Right now it's computed once // per generator monomorphization, but it doesn't depend on substs. fn generator_layout_and_saved_local_names<'tcx>( tcx: TyCtxt<'tcx>, def_id: DefId, ) -> (&'tcx GeneratorLayout<'tcx>, IndexVec>) { let body = tcx.optimized_mir(def_id); let generator_layout = body.generator_layout().unwrap(); let mut generator_saved_local_names = IndexVec::from_elem(None, &generator_layout.field_tys); let state_arg = mir::Local::new(1); for var in &body.var_debug_info { let mir::VarDebugInfoContents::Place(place) = &var.value else { continue }; if place.local != state_arg { continue; } match place.projection[..] { [ // Deref of the `Pin<&mut Self>` state argument. mir::ProjectionElem::Field(..), mir::ProjectionElem::Deref, // Field of a variant of the state. mir::ProjectionElem::Downcast(_, variant), mir::ProjectionElem::Field(field, _), ] => { let name = &mut generator_saved_local_names [generator_layout.variant_fields[variant][field]]; if name.is_none() { name.replace(var.name); } } _ => {} } } (generator_layout, generator_saved_local_names) } /// Computes the type parameters for a type, if any, for the given metadata. fn build_generic_type_param_di_nodes<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>, ) -> SmallVec<&'ll DIType> { if let ty::Adt(def, substs) = *ty.kind() { if substs.types().next().is_some() { let generics = cx.tcx.generics_of(def.did()); let names = get_parameter_names(cx, generics); let template_params: SmallVec<_> = iter::zip(substs, names) .filter_map(|(kind, name)| { if let GenericArgKind::Type(ty) = kind.unpack() { let actual_type = cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty); let actual_type_di_node = type_di_node(cx, actual_type); let name = name.as_str(); Some(unsafe { llvm::LLVMRustDIBuilderCreateTemplateTypeParameter( DIB(cx), None, name.as_ptr().cast(), name.len(), actual_type_di_node, ) }) } else { None } }) .collect(); return template_params; } } return smallvec![]; fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec { let mut names = generics .parent .map_or_else(Vec::new, |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id))); names.extend(generics.params.iter().map(|param| param.name)); names } } /// Creates debug information for the given global variable. /// /// Adds the created debuginfo nodes directly to the crate's IR. pub fn build_global_var_di_node<'ll>(cx: &CodegenCx<'ll, '_>, def_id: DefId, global: &'ll Value) { if cx.dbg_cx.is_none() { return; } // Only create type information if full debuginfo is enabled if cx.sess().opts.debuginfo != DebugInfo::Full { return; } let tcx = cx.tcx; // We may want to remove the namespace scope if we're in an extern block (see // https://github.com/rust-lang/rust/pull/46457#issuecomment-351750952). let var_scope = get_namespace_for_item(cx, def_id); let span = tcx.def_span(def_id); let (file_metadata, line_number) = if !span.is_dummy() { let loc = cx.lookup_debug_loc(span.lo()); (file_metadata(cx, &loc.file), loc.line) } else { (unknown_file_metadata(cx), UNKNOWN_LINE_NUMBER) }; let is_local_to_unit = is_node_local_to_unit(cx, def_id); let variable_type = Instance::mono(cx.tcx, def_id).ty(cx.tcx, ty::ParamEnv::reveal_all()); let type_di_node = type_di_node(cx, variable_type); let var_name = tcx.item_name(def_id); let var_name = var_name.as_str(); let linkage_name = mangled_name_of_instance(cx, Instance::mono(tcx, def_id)).name; // When empty, linkage_name field is omitted, // which is what we want for no_mangle statics let linkage_name = if var_name == linkage_name { "" } else { linkage_name }; let global_align = cx.align_of(variable_type); unsafe { llvm::LLVMRustDIBuilderCreateStaticVariable( DIB(cx), Some(var_scope), var_name.as_ptr().cast(), var_name.len(), linkage_name.as_ptr().cast(), linkage_name.len(), file_metadata, line_number, type_di_node, is_local_to_unit, global, None, global_align.bits() as u32, ); } } /// Generates LLVM debuginfo for a vtable. /// /// The vtable type looks like a struct with a field for each function pointer and super-trait /// pointer it contains (plus the `size` and `align` fields). /// /// Except for `size`, `align`, and `drop_in_place`, the field names don't try to mirror /// the name of the method they implement. This can be implemented in the future once there /// is a proper disambiguation scheme for dealing with methods from different traits that have /// the same name. fn build_vtable_type_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>, poly_trait_ref: Option>, ) -> &'ll DIType { let tcx = cx.tcx; let vtable_entries = if let Some(poly_trait_ref) = poly_trait_ref { let trait_ref = poly_trait_ref.with_self_ty(tcx, ty); let trait_ref = tcx.erase_regions(trait_ref); tcx.vtable_entries(trait_ref) } else { TyCtxt::COMMON_VTABLE_ENTRIES }; // All function pointers are described as opaque pointers. This could be improved in the future // by describing them as actual function pointers. let void_pointer_ty = tcx.mk_imm_ptr(tcx.types.unit); let void_pointer_type_di_node = type_di_node(cx, void_pointer_ty); let usize_di_node = type_di_node(cx, tcx.types.usize); let (pointer_size, pointer_align) = cx.size_and_align_of(void_pointer_ty); // If `usize` is not pointer-sized and -aligned then the size and alignment computations // for the vtable as a whole would be wrong. Let's make sure this holds even on weird // platforms. assert_eq!(cx.size_and_align_of(tcx.types.usize), (pointer_size, pointer_align)); let vtable_type_name = compute_debuginfo_vtable_name(cx.tcx, ty, poly_trait_ref, VTableNameKind::Type); let unique_type_id = UniqueTypeId::for_vtable_ty(tcx, ty, poly_trait_ref); let size = pointer_size * vtable_entries.len() as u64; // This gets mapped to a DW_AT_containing_type attribute which allows GDB to correlate // the vtable to the type it is for. let vtable_holder = type_di_node(cx, ty); build_type_with_children( cx, type_map::stub( cx, Stub::VTableTy { vtable_holder }, unique_type_id, &vtable_type_name, (size, pointer_align), NO_SCOPE_METADATA, DIFlags::FlagArtificial, ), |cx, vtable_type_di_node| { vtable_entries .iter() .enumerate() .filter_map(|(index, vtable_entry)| { let (field_name, field_type_di_node) = match vtable_entry { ty::VtblEntry::MetadataDropInPlace => { ("drop_in_place".to_string(), void_pointer_type_di_node) } ty::VtblEntry::Method(_) => { // Note: This code does not try to give a proper name to each method // because their might be multiple methods with the same name // (coming from different traits). (format!("__method{}", index), void_pointer_type_di_node) } ty::VtblEntry::TraitVPtr(_) => { (format!("__super_trait_ptr{}", index), void_pointer_type_di_node) } ty::VtblEntry::MetadataAlign => ("align".to_string(), usize_di_node), ty::VtblEntry::MetadataSize => ("size".to_string(), usize_di_node), ty::VtblEntry::Vacant => return None, }; let field_offset = pointer_size * index as u64; Some(build_field_di_node( cx, vtable_type_di_node, &field_name, (pointer_size, pointer_align), field_offset, DIFlags::FlagZero, field_type_di_node, )) }) .collect() }, NO_GENERICS, ) .di_node } fn vcall_visibility_metadata<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>, trait_ref: Option>, vtable: &'ll Value, ) { enum VCallVisibility { Public = 0, LinkageUnit = 1, TranslationUnit = 2, } let Some(trait_ref) = trait_ref else { return }; let trait_ref_self = trait_ref.with_self_ty(cx.tcx, ty); let trait_ref_self = cx.tcx.erase_regions(trait_ref_self); let trait_def_id = trait_ref_self.def_id(); let trait_vis = cx.tcx.visibility(trait_def_id); let cgus = cx.sess().codegen_units(); let single_cgu = cgus == 1; let lto = cx.sess().lto(); // Since LLVM requires full LTO for the virtual function elimination optimization to apply, // only the `Lto::Fat` cases are relevant currently. let vcall_visibility = match (lto, trait_vis, single_cgu) { // If there is not LTO and the visibility in public, we have to assume that the vtable can // be seen from anywhere. With multiple CGUs, the vtable is quasi-public. (Lto::No | Lto::ThinLocal, Visibility::Public, _) | (Lto::No, Visibility::Restricted(_) | Visibility::Invisible, false) => { VCallVisibility::Public } // With LTO and a quasi-public visibility, the usages of the functions of the vtable are // all known by the `LinkageUnit`. // FIXME: LLVM only supports this optimization for `Lto::Fat` currently. Once it also // supports `Lto::Thin` the `VCallVisibility` may have to be adjusted for those. (Lto::Fat | Lto::Thin, Visibility::Public, _) | ( Lto::ThinLocal | Lto::Thin | Lto::Fat, Visibility::Restricted(_) | Visibility::Invisible, false, ) => VCallVisibility::LinkageUnit, // If there is only one CGU, private vtables can only be seen by that CGU/translation unit // and therefore we know of all usages of functions in the vtable. (_, Visibility::Restricted(_) | Visibility::Invisible, true) => { VCallVisibility::TranslationUnit } }; let trait_ref_typeid = typeid_for_trait_ref(cx.tcx, trait_ref); unsafe { let typeid = llvm::LLVMMDStringInContext( cx.llcx, trait_ref_typeid.as_ptr() as *const c_char, trait_ref_typeid.as_bytes().len() as c_uint, ); let v = [cx.const_usize(0), typeid]; llvm::LLVMRustGlobalAddMetadata( vtable, llvm::MD_type as c_uint, llvm::LLVMValueAsMetadata(llvm::LLVMMDNodeInContext( cx.llcx, v.as_ptr(), v.len() as c_uint, )), ); let vcall_visibility = llvm::LLVMValueAsMetadata(cx.const_u64(vcall_visibility as u64)); let vcall_visibility_metadata = llvm::LLVMMDNodeInContext2(cx.llcx, &vcall_visibility, 1); llvm::LLVMGlobalSetMetadata( vtable, llvm::MetadataType::MD_vcall_visibility as c_uint, vcall_visibility_metadata, ); } } /// Creates debug information for the given vtable, which is for the /// given type. /// /// Adds the created metadata nodes directly to the crate's IR. pub fn create_vtable_di_node<'ll, 'tcx>( cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>, poly_trait_ref: Option>, vtable: &'ll Value, ) { // FIXME(flip1995): The virtual function elimination optimization only works with full LTO in // LLVM at the moment. if cx.sess().opts.unstable_opts.virtual_function_elimination && cx.sess().lto() == Lto::Fat { vcall_visibility_metadata(cx, ty, poly_trait_ref, vtable); } if cx.dbg_cx.is_none() { return; } // Only create type information if full debuginfo is enabled if cx.sess().opts.debuginfo != DebugInfo::Full { return; } let vtable_name = compute_debuginfo_vtable_name(cx.tcx, ty, poly_trait_ref, VTableNameKind::GlobalVariable); let vtable_type_di_node = build_vtable_type_di_node(cx, ty, poly_trait_ref); let linkage_name = ""; unsafe { llvm::LLVMRustDIBuilderCreateStaticVariable( DIB(cx), NO_SCOPE_METADATA, vtable_name.as_ptr().cast(), vtable_name.len(), linkage_name.as_ptr().cast(), linkage_name.len(), unknown_file_metadata(cx), UNKNOWN_LINE_NUMBER, vtable_type_di_node, true, vtable, None, 0, ); } } /// Creates an "extension" of an existing `DIScope` into another file. pub fn extend_scope_to_file<'ll>( cx: &CodegenCx<'ll, '_>, scope_metadata: &'ll DIScope, file: &SourceFile, ) -> &'ll DILexicalBlock { let file_metadata = file_metadata(cx, file); unsafe { llvm::LLVMRustDIBuilderCreateLexicalBlockFile(DIB(cx), scope_metadata, file_metadata) } } pub fn tuple_field_name(field_index: usize) -> Cow<'static, str> { const TUPLE_FIELD_NAMES: [&'static str; 16] = [ "__0", "__1", "__2", "__3", "__4", "__5", "__6", "__7", "__8", "__9", "__10", "__11", "__12", "__13", "__14", "__15", ]; TUPLE_FIELD_NAMES .get(field_index) .map(|s| Cow::from(*s)) .unwrap_or_else(|| Cow::from(format!("__{}", field_index))) }