bjoernager/rust
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rust/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

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use self::MemberDescriptionFactory::*;
use self::RecursiveTypeDescription::*;
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::CrateDebugContext;
use crate::abi;
use crate::common::CodegenCx;
use crate::debuginfo::utils::fat_pointer_kind;
use crate::debuginfo::utils::FatPtrKind;
use crate::llvm;
use crate::llvm::debuginfo::{
DIArray, DICompositeType, 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::traits::*;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
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::{self, IntegerExt, LayoutOf, PrimitiveExt, TyAndLayout};
use rustc_middle::ty::subst::GenericArgKind;
use rustc_middle::ty::{
self, AdtKind, GeneratorSubsts, Instance, ParamEnv, Ty, TyCtxt, COMMON_VTABLE_ENTRIES,
};
use rustc_query_system::ich::NodeIdHashingMode;
use rustc_session::config::{self, DebugInfo};
use rustc_span::symbol::Symbol;
use rustc_span::FileNameDisplayPreference;
use rustc_span::{self, SourceFile, SourceFileHash};
use rustc_target::abi::{Abi, Align, HasDataLayout, Integer, TagEncoding};
use rustc_target::abi::{Int, Pointer, F32, F64};
use rustc_target::abi::{Primitive, Size, VariantIdx, Variants};
use tracing::debug;
use libc::{c_longlong, c_uint};
use std::collections::hash_map::Entry;
use std::fmt::{self, Write};
use std::hash::{Hash, Hasher};
use std::iter;
use std::path::{Path, PathBuf};
use std::ptr;
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<H: Hasher>(&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_unsigned_char: c_uint = 0x08;
pub const UNKNOWN_LINE_NUMBER: c_uint = 0;
pub const UNKNOWN_COLUMN_NUMBER: c_uint = 0;
pub const NO_SCOPE_METADATA: Option<&DIScope> = None;
mod unique_type_id {
use super::*;
use rustc_arena::DroplessArena;
#[derive(Copy, Hash, Eq, PartialEq, Clone)]
pub(super) struct UniqueTypeId(u32);
// The `&'static str`s in this type actually point into the arena.
//
// The `FxHashMap`+`Vec` pair could be replaced by `FxIndexSet`, but #75278
// found that to regress performance up to 2% in some cases. This might be
// revisited after further improvements to `indexmap`.
#[derive(Default)]
pub(super) struct TypeIdInterner {
arena: DroplessArena,
names: FxHashMap<&'static str, UniqueTypeId>,
strings: Vec<&'static str>,
}
impl TypeIdInterner {
#[inline]
pub(super) fn intern(&mut self, string: &str) -> UniqueTypeId {
if let Some(&name) = self.names.get(string) {
return name;
}
let name = UniqueTypeId(self.strings.len() as u32);
// `from_utf8_unchecked` is safe since we just allocated a `&str` which is known to be
// UTF-8.
let string: &str =
unsafe { std::str::from_utf8_unchecked(self.arena.alloc_slice(string.as_bytes())) };
// It is safe to extend the arena allocation to `'static` because we only access
// these while the arena is still alive.
let string: &'static str = unsafe { &*(string as *const str) };
self.strings.push(string);
self.names.insert(string, name);
name
}
// Get the symbol as a string. `Symbol::as_str()` should be used in
// preference to this function.
pub(super) fn get(&self, symbol: UniqueTypeId) -> &str {
self.strings[symbol.0 as usize]
}
}
}
use unique_type_id::*;
/// The `TypeMap` is where the `CrateDebugContext` holds the type metadata nodes
/// created so far. The metadata nodes are indexed by `UniqueTypeId`, and, for
/// faster lookup, also by `Ty`. The `TypeMap` is responsible for creating
/// `UniqueTypeId`s.
#[derive(Default)]
pub struct TypeMap<'ll, 'tcx> {
/// The `UniqueTypeId`s created so far.
unique_id_interner: TypeIdInterner,
/// A map from `UniqueTypeId` to debuginfo metadata for that type. This is a 1:1 mapping.
unique_id_to_metadata: FxHashMap<UniqueTypeId, &'ll DIType>,
/// A map from types to debuginfo metadata. This is an N:1 mapping.
type_to_metadata: FxHashMap<Ty<'tcx>, &'ll DIType>,
/// A map from types to `UniqueTypeId`. This is an N:1 mapping.
type_to_unique_id: FxHashMap<Ty<'tcx>, UniqueTypeId>,
}
impl<'ll, 'tcx> TypeMap<'ll, 'tcx> {
/// Adds a Ty to metadata mapping to the TypeMap. The method will fail if
/// the mapping already exists.
fn register_type_with_metadata(&mut self, type_: Ty<'tcx>, metadata: &'ll DIType) {
if self.type_to_metadata.insert(type_, metadata).is_some() {
bug!("type metadata for `Ty` '{}' is already in the `TypeMap`!", type_);
}
}
/// Removes a `Ty`-to-metadata mapping.
/// This is useful when computing the metadata for a potentially
/// recursive type (e.g., a function pointer of the form:
///
/// fn foo() -> impl Copy { foo }
///
/// This kind of type cannot be properly represented
/// via LLVM debuginfo. As a workaround,
/// we register a temporary Ty to metadata mapping
/// for the function before we compute its actual metadata.
/// If the metadata computation ends up recursing back to the
/// original function, it will use the temporary mapping
/// for the inner self-reference, preventing us from
/// recursing forever.
///
/// This function is used to remove the temporary metadata
/// mapping after we've computed the actual metadata.
fn remove_type(&mut self, type_: Ty<'tcx>) {
if self.type_to_metadata.remove(type_).is_none() {
bug!("type metadata `Ty` '{}' is not in the `TypeMap`!", type_);
}
}
/// Adds a `UniqueTypeId` to metadata mapping to the `TypeMap`. The method will
/// fail if the mapping already exists.
fn register_unique_id_with_metadata(
&mut self,
unique_type_id: UniqueTypeId,
metadata: &'ll DIType,
) {
if self.unique_id_to_metadata.insert(unique_type_id, metadata).is_some() {
bug!(
"type metadata for unique ID '{}' is already in the `TypeMap`!",
self.get_unique_type_id_as_string(unique_type_id)
);
}
}
fn find_metadata_for_type(&self, type_: Ty<'tcx>) -> Option<&'ll DIType> {
self.type_to_metadata.get(&type_).cloned()
}
fn find_metadata_for_unique_id(&self, unique_type_id: UniqueTypeId) -> Option<&'ll DIType> {
self.unique_id_to_metadata.get(&unique_type_id).cloned()
}
/// Gets the string representation of a `UniqueTypeId`. This method will fail if
/// the ID is unknown.
fn get_unique_type_id_as_string(&self, unique_type_id: UniqueTypeId) -> &str {
self.unique_id_interner.get(unique_type_id)
}
/// Gets the `UniqueTypeId` for the given type. If the `UniqueTypeId` for the given
/// type has been requested before, this is just a table lookup. Otherwise, an
/// ID will be generated and stored for later lookup.
fn get_unique_type_id_of_type<'a>(
&mut self,
cx: &CodegenCx<'a, 'tcx>,
type_: Ty<'tcx>,
) -> UniqueTypeId {
// Let's see if we already have something in the cache.
if let Some(unique_type_id) = self.type_to_unique_id.get(&type_).cloned() {
return unique_type_id;
}
// If not, generate one.
// The hasher we are using to generate the UniqueTypeId. We want
// something that provides more than the 64 bits of the DefaultHasher.
let mut hasher = StableHasher::new();
let mut hcx = cx.tcx.create_stable_hashing_context();
let type_ = cx.tcx.erase_regions(type_);
hcx.while_hashing_spans(false, |hcx| {
hcx.with_node_id_hashing_mode(NodeIdHashingMode::HashDefPath, |hcx| {
type_.hash_stable(hcx, &mut hasher);
});
});
let unique_type_id = hasher.finish::<Fingerprint>().to_hex();
let key = self.unique_id_interner.intern(&unique_type_id);
self.type_to_unique_id.insert(type_, key);
key
}
/// Gets the `UniqueTypeId` for an enum variant. Enum variants are not really
/// types of their own, so they need special handling. We still need a
/// `UniqueTypeId` for them, since to debuginfo they *are* real types.
fn get_unique_type_id_of_enum_variant<'a>(
&mut self,
cx: &CodegenCx<'a, 'tcx>,
enum_type: Ty<'tcx>,
variant_name: &str,
) -> UniqueTypeId {
let enum_type_id = self.get_unique_type_id_of_type(cx, enum_type);
let enum_variant_type_id =
format!("{}::{}", self.get_unique_type_id_as_string(enum_type_id), variant_name);
let interner_key = self.unique_id_interner.intern(&enum_variant_type_id);
interner_key
}
/// Gets the unique type ID string for an enum variant part.
/// Variant parts are not types and shouldn't really have their own ID,
/// but it makes `set_members_of_composite_type()` simpler.
fn get_unique_type_id_str_of_enum_variant_part(
&mut self,
enum_type_id: UniqueTypeId,
) -> String {
format!("{}_variant_part", self.get_unique_type_id_as_string(enum_type_id))
}
}
/// A description of some recursive type. It can either be already finished (as
/// with `FinalMetadata`) or it is not yet finished, but contains all information
/// needed to generate the missing parts of the description. See the
/// documentation section on Recursive Types at the top of this file for more
/// information.
enum RecursiveTypeDescription<'ll, 'tcx> {
UnfinishedMetadata {
unfinished_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
metadata_stub: &'ll DICompositeType,
member_holding_stub: &'ll DICompositeType,
member_description_factory: MemberDescriptionFactory<'ll, 'tcx>,
},
FinalMetadata(&'ll DICompositeType),
}
fn create_and_register_recursive_type_forward_declaration<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
unfinished_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
metadata_stub: &'ll DICompositeType,
member_holding_stub: &'ll DICompositeType,
member_description_factory: MemberDescriptionFactory<'ll, 'tcx>,
) -> RecursiveTypeDescription<'ll, 'tcx> {
// Insert the stub into the `TypeMap` in order to allow for recursive references.
let mut type_map = debug_context(cx).type_map.borrow_mut();
type_map.register_unique_id_with_metadata(unique_type_id, metadata_stub);
type_map.register_type_with_metadata(unfinished_type, metadata_stub);
UnfinishedMetadata {
unfinished_type,
unique_type_id,
metadata_stub,
member_holding_stub,
member_description_factory,
}
}
impl<'ll, 'tcx> RecursiveTypeDescription<'ll, 'tcx> {
/// Finishes up the description of the type in question (mostly by providing
/// descriptions of the fields of the given type) and returns the final type
/// metadata.
fn finalize(&self, cx: &CodegenCx<'ll, 'tcx>) -> MetadataCreationResult<'ll> {
match *self {
FinalMetadata(metadata) => MetadataCreationResult::new(metadata, false),
UnfinishedMetadata {
unfinished_type,
unique_type_id,
metadata_stub,
member_holding_stub,
ref member_description_factory,
} => {
// Make sure that we have a forward declaration of the type in
// the TypeMap so that recursive references are possible. This
// will always be the case if the RecursiveTypeDescription has
// been properly created through the
// `create_and_register_recursive_type_forward_declaration()`
// function.
{
let type_map = debug_context(cx).type_map.borrow();
if type_map.find_metadata_for_unique_id(unique_type_id).is_none()
|| type_map.find_metadata_for_type(unfinished_type).is_none()
{
bug!(
"Forward declaration of potentially recursive type \
'{:?}' was not found in TypeMap!",
unfinished_type
);
}
}
// ... then create the member descriptions ...
let member_descriptions = member_description_factory.create_member_descriptions(cx);
// ... and attach them to the stub to complete it.
set_members_of_composite_type(
cx,
unfinished_type,
member_holding_stub,
member_descriptions,
None,
);
MetadataCreationResult::new(metadata_stub, true)
}
}
}
}
/// Returns from the enclosing function if the type metadata with the given
/// unique ID can be found in the type map.
macro_rules! return_if_metadata_created_in_meantime {
($cx: expr, $unique_type_id: expr) => {
if let Some(metadata) =
debug_context($cx).type_map.borrow().find_metadata_for_unique_id($unique_type_id)
{
return MetadataCreationResult::new(metadata, true);
}
};
}
/// Creates debuginfo for a fixed size array (e.g. `[u64; 123]`).
/// For slices (that is, "arrays" of unknown size) use [slice_type_metadata].
fn fixed_size_array_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
unique_type_id: UniqueTypeId,
array_type: Ty<'tcx>,
) -> MetadataCreationResult<'ll> {
let ty::Array(element_type, len) = array_type.kind() else {
bug!("fixed_size_array_metadata() called with non-ty::Array type `{:?}`", array_type)
};
let element_type_metadata = type_metadata(cx, element_type);
return_if_metadata_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 metadata = unsafe {
llvm::LLVMRustDIBuilderCreateArrayType(
DIB(cx),
size.bits(),
align.bits() as u32,
element_type_metadata,
subscripts,
)
};
MetadataCreationResult::new(metadata, 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 pointer_or_reference_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
ptr_type: Ty<'tcx>,
pointee_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
) -> MetadataCreationResult<'ll> {
let pointee_type_metadata = type_metadata(cx, pointee_type);
return_if_metadata_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);
let pointer_type_metadata = 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)
);
unsafe {
llvm::LLVMRustDIBuilderCreatePointerType(
DIB(cx),
pointee_type_metadata,
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(),
)
}
}
Some(fat_pointer_kind) => {
let layout = cx.layout_of(ptr_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_metadata = unsafe {
llvm::LLVMRustDIBuilderCreatePointerType(
DIB(cx),
pointee_type_metadata,
addr_field.size.bits(),
addr_field.align.abi.bits() as u32,
0, // Ignore DWARF address space.
std::ptr::null(),
0,
)
};
let member_descriptions = vec![
MemberDescription {
name: addr_field_name.into(),
type_metadata: data_ptr_type_metadata,
offset: layout.fields.offset(abi::FAT_PTR_ADDR),
size: addr_field.size,
align: addr_field.align.abi,
flags: DIFlags::FlagArtificial,
discriminant: None,
source_info: None,
},
MemberDescription {
name: extra_field_name.into(),
type_metadata: type_metadata(cx, extra_field.ty),
offset: layout.fields.offset(abi::FAT_PTR_EXTRA),
size: extra_field.size,
align: extra_field.align.abi,
flags: DIFlags::FlagArtificial,
discriminant: None,
source_info: None,
},
];
composite_type_metadata(
cx,
ptr_type,
&ptr_type_debuginfo_name,
unique_type_id,
member_descriptions,
NO_SCOPE_METADATA,
)
}
};
MetadataCreationResult { metadata: pointer_type_metadata, already_stored_in_typemap: false }
}
fn subroutine_type_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
unique_type_id: UniqueTypeId,
signature: ty::PolyFnSig<'tcx>,
) -> MetadataCreationResult<'ll> {
let signature =
cx.tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), signature);
let signature_metadata: Vec<_> = iter::once(
// return type
match signature.output().kind() {
ty::Tuple(tys) if tys.is_empty() => None,
_ => Some(type_metadata(cx, signature.output())),
},
)
.chain(
// regular arguments
signature.inputs().iter().map(|argument_type| Some(type_metadata(cx, argument_type))),
)
.collect();
return_if_metadata_created_in_meantime!(cx, unique_type_id);
MetadataCreationResult::new(
unsafe {
llvm::LLVMRustDIBuilderCreateSubroutineType(
DIB(cx),
create_DIArray(DIB(cx), &signature_metadata[..]),
)
},
false,
)
}
// Create debuginfo for `dyn SomeTrait` types. Currently these are empty structs
// we with the correct type name (e.g. "dyn SomeTrait<Foo, Item=u32> + Sync").
fn dyn_type_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
dyn_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
) -> &'ll DIType {
if let ty::Dynamic(..) = dyn_type.kind() {
let type_name = compute_debuginfo_type_name(cx.tcx, dyn_type, true);
composite_type_metadata(cx, dyn_type, &type_name, unique_type_id, vec![], NO_SCOPE_METADATA)
} else {
bug!("Only ty::Dynamic is valid for dyn_type_metadata(). 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 slice_type_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
slice_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
) -> MetadataCreationResult<'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 slice_type_metadata(). Found {:?} instead.",
slice_type
)
}
};
let element_type_metadata = type_metadata(cx, element_type);
return_if_metadata_created_in_meantime!(cx, unique_type_id);
MetadataCreationResult { metadata: element_type_metadata, already_stored_in_typemap: false }
}
pub fn type_metadata<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll DIType {
// Get the unique type ID of this type.
let unique_type_id = {
let mut type_map = debug_context(cx).type_map.borrow_mut();
// First, try to find the type in `TypeMap`. If we have seen it before, we
// can exit early here.
match type_map.find_metadata_for_type(t) {
Some(metadata) => {
return metadata;
}
None => {
// The Ty is not in the `TypeMap` but maybe we have already seen
// an equivalent type (e.g., only differing in region arguments).
// In order to find out, generate the unique type ID and look
// that up.
let unique_type_id = type_map.get_unique_type_id_of_type(cx, t);
match type_map.find_metadata_for_unique_id(unique_type_id) {
Some(metadata) => {
// There is already an equivalent type in the TypeMap.
// Register this Ty as an alias in the cache and
// return the cached metadata.
type_map.register_type_with_metadata(t, metadata);
return metadata;
}
None => {
// There really is no type metadata for this type, so
// proceed by creating it.
unique_type_id
}
}
}
}
};
debug!("type_metadata: {:?}", t);
let MetadataCreationResult { metadata, already_stored_in_typemap } = match *t.kind() {
ty::Never | ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) => {
MetadataCreationResult::new(basic_type_metadata(cx, t), false)
}
ty::Tuple(elements) if elements.is_empty() => {
MetadataCreationResult::new(basic_type_metadata(cx, t), false)
}
ty::Array(..) => fixed_size_array_metadata(cx, unique_type_id, t),
ty::Slice(_) | ty::Str => slice_type_metadata(cx, t, unique_type_id),
ty::Dynamic(..) => {
MetadataCreationResult::new(dyn_type_metadata(cx, t, unique_type_id), false)
}
ty::Foreign(..) => {
MetadataCreationResult::new(foreign_type_metadata(cx, t, unique_type_id), false)
}
ty::RawPtr(ty::TypeAndMut { ty: pointee_type, .. }) | ty::Ref(_, pointee_type, _) => {
pointer_or_reference_metadata(cx, t, pointee_type, unique_type_id)
}
ty::Adt(def, _) if def.is_box() => {
pointer_or_reference_metadata(cx, t, t.boxed_ty(), unique_type_id)
}
ty::FnDef(..) | ty::FnPtr(_) => {
if let Some(metadata) =
debug_context(cx).type_map.borrow().find_metadata_for_unique_id(unique_type_id)
{
return metadata;
}
// It's possible to create a self-referential
// type in Rust by using 'impl trait':
//
// fn foo() -> impl Copy { foo }
//
// See `TypeMap::remove_type` for more detals
// about the workaround.
let temp_type = {
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.
let name = "<recur_type>";
llvm::LLVMRustDIBuilderCreateBasicType(
DIB(cx),
name.as_ptr().cast(),
name.len(),
cx.size_of(t).bits(),
DW_ATE_unsigned,
)
}
};
let type_map = &debug_context(cx).type_map;
type_map.borrow_mut().register_type_with_metadata(t, temp_type);
let fn_metadata =
subroutine_type_metadata(cx, unique_type_id, t.fn_sig(cx.tcx)).metadata;
type_map.borrow_mut().remove_type(t);
// This is actually a function pointer, so wrap it in pointer DI.
let (pointer_size, pointer_align) =
cx.size_and_align_of(cx.tcx.mk_imm_ptr(cx.tcx.mk_unit()));
let name = compute_debuginfo_type_name(cx.tcx, t, false);
let md = unsafe {
llvm::LLVMRustDIBuilderCreatePointerType(
DIB(cx),
fn_metadata,
pointer_size.bits(),
pointer_align.bits() as u32,
0, // Ignore DWARF address space.
name.as_ptr().cast(),
name.len(),
)
};
MetadataCreationResult::new(md, false)
}
ty::Closure(def_id, substs) => {
let upvar_tys: Vec<_> = substs.as_closure().upvar_tys().collect();
let containing_scope = get_namespace_for_item(cx, def_id);
prepare_tuple_metadata(cx, t, &upvar_tys, unique_type_id, Some(containing_scope))
.finalize(cx)
}
ty::Generator(def_id, substs, _) => {
let upvar_tys: Vec<_> = substs
.as_generator()
.prefix_tys()
.map(|t| cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), t))
.collect();
prepare_enum_metadata(cx, t, def_id, unique_type_id, upvar_tys).finalize(cx)
}
ty::Adt(def, ..) => match def.adt_kind() {
AdtKind::Struct => prepare_struct_metadata(cx, t, unique_type_id).finalize(cx),
AdtKind::Union => prepare_union_metadata(cx, t, unique_type_id).finalize(cx),
AdtKind::Enum => {
prepare_enum_metadata(cx, t, def.did, unique_type_id, vec![]).finalize(cx)
}
},
ty::Tuple(elements) => {
let tys: Vec<_> = elements.iter().map(|k| k.expect_ty()).collect();
prepare_tuple_metadata(cx, t, &tys, unique_type_id, NO_SCOPE_METADATA).finalize(cx)
}
// Type parameters from polymorphized functions.
ty::Param(_) => MetadataCreationResult::new(param_type_metadata(cx, t), false),
_ => bug!("debuginfo: unexpected type in type_metadata: {:?}", t),
};
{
let mut type_map = debug_context(cx).type_map.borrow_mut();
if already_stored_in_typemap {
// Also make sure that we already have a `TypeMap` entry for the unique type ID.
let metadata_for_uid = match type_map.find_metadata_for_unique_id(unique_type_id) {
Some(metadata) => metadata,
None => {
bug!(
"expected type metadata for unique \
type ID '{}' to already be in \
the `debuginfo::TypeMap` but it \
was not. (Ty = {})",
type_map.get_unique_type_id_as_string(unique_type_id),
t
);
}
};
match type_map.find_metadata_for_type(t) {
Some(metadata) => {
if metadata != metadata_for_uid {
bug!(
"mismatch between `Ty` and \
`UniqueTypeId` maps in \
`debuginfo::TypeMap`. \
UniqueTypeId={}, Ty={}",
type_map.get_unique_type_id_as_string(unique_type_id),
t
);
}
}
None => {
type_map.register_type_with_metadata(t, metadata);
}
}
} else {
type_map.register_type_with_metadata(t, metadata);
type_map.register_unique_id_with_metadata(unique_type_id, metadata);
}
}
metadata
}
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 {
debug!("file_metadata: file_name: {:?}", source_file.name);
let hash = Some(&source_file.src_hash);
let file_name = Some(source_file.name.prefer_remapped().to_string());
let directory = if source_file.is_real_file() && !source_file.is_imported() {
Some(
cx.sess()
.opts
.working_dir
.to_string_lossy(FileNameDisplayPreference::Remapped)
.to_string(),
)
} else {
// If the path comes from an upstream crate we assume it has been made
// independent of the compiler's working directory one way or another.
None
};
file_metadata_raw(cx, file_name, directory, hash)
}
pub fn unknown_file_metadata<'ll>(cx: &CodegenCx<'ll, '_>) -> &'ll DIFile {
file_metadata_raw(cx, None, None, None)
}
fn file_metadata_raw<'ll>(
cx: &CodegenCx<'ll, '_>,
file_name: Option<String>,
directory: Option<String>,
hash: Option<&SourceFileHash>,
) -> &'ll DIFile {
let key = (file_name, directory);
match debug_context(cx).created_files.borrow_mut().entry(key) {
Entry::Occupied(o) => o.get(),
Entry::Vacant(v) => {
let (file_name, directory) = v.key();
debug!("file_metadata: file_name: {:?}, directory: {:?}", file_name, directory);
let file_name = file_name.as_deref().unwrap_or("<unknown>");
let directory = directory.as_deref().unwrap_or("");
let (hash_kind, hash_value) = match hash {
Some(hash) => {
let kind = match hash.kind {
rustc_span::SourceFileHashAlgorithm::Md5 => llvm::ChecksumKind::MD5,
rustc_span::SourceFileHashAlgorithm::Sha1 => llvm::ChecksumKind::SHA1,
rustc_span::SourceFileHashAlgorithm::Sha256 => llvm::ChecksumKind::SHA256,
};
(kind, hex_encode(hash.hash_bytes()))
}
None => (llvm::ChecksumKind::None, String::new()),
};
let file_metadata = 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(),
)
};
v.insert(file_metadata);
file_metadata
}
}
}
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 basic_type_metadata<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll DIType {
debug!("basic_type_metadata: {:?}", 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() => ("()", DW_ATE_unsigned),
ty::Bool => ("bool", DW_ATE_boolean),
ty::Char => ("char", DW_ATE_unsigned_char),
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::basic_type_metadata - `t` is invalid type"),
};
let ty_metadata = unsafe {
llvm::LLVMRustDIBuilderCreateBasicType(
DIB(cx),
name.as_ptr().cast(),
name.len(),
cx.size_of(t).bits(),
encoding,
)
};
if !cpp_like_debuginfo {
return ty_metadata;
}
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 ty_metadata,
};
let typedef_metadata = unsafe {
llvm::LLVMRustDIBuilderCreateTypedef(
DIB(cx),
ty_metadata,
typedef_name.as_ptr().cast(),
typedef_name.len(),
unknown_file_metadata(cx),
0,
None,
)
};
typedef_metadata
}
fn foreign_type_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
t: Ty<'tcx>,
unique_type_id: UniqueTypeId,
) -> &'ll DIType {
debug!("foreign_type_metadata: {:?}", t);
let name = compute_debuginfo_type_name(cx.tcx, t, false);
create_struct_stub(cx, t, &name, unique_type_id, NO_SCOPE_METADATA, DIFlags::FlagZero)
}
fn param_type_metadata<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll DIType {
debug!("param_type_metadata: {:?}", t);
let name = format!("{:?}", t);
unsafe {
llvm::LLVMRustDIBuilderCreateBasicType(
DIB(cx),
name.as_ptr().cast(),
name.len(),
Size::ZERO.bits(),
DW_ATE_unsigned,
)
}
}
pub fn compile_unit_metadata<'ll, 'tcx>(
tcx: TyCtxt<'tcx>,
codegen_unit_name: &str,
debug_context: &CrateDebugContext<'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!("compile_unit_metadata: {:?}", 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.debugging_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.debugging_opts.split_dwarf_inlining,
);
if tcx.sess.opts.debugging_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.debugging_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,
)
}
}
}
struct MetadataCreationResult<'ll> {
metadata: &'ll DIType,
already_stored_in_typemap: bool,
}
impl<'ll> MetadataCreationResult<'ll> {
fn new(metadata: &'ll DIType, already_stored_in_typemap: bool) -> Self {
MetadataCreationResult { metadata, already_stored_in_typemap }
}
}
#[derive(Debug)]
struct SourceInfo<'ll> {
file: &'ll DIFile,
line: u32,
}
/// Description of a type member, which can either be a regular field (as in
/// structs or tuples) or an enum variant.
#[derive(Debug)]
struct MemberDescription<'ll> {
name: String,
type_metadata: &'ll DIType,
offset: Size,
size: Size,
align: Align,
flags: DIFlags,
discriminant: Option<u64>,
source_info: Option<SourceInfo<'ll>>,
}
impl<'ll> MemberDescription<'ll> {
fn into_metadata(
self,
cx: &CodegenCx<'ll, '_>,
composite_type_metadata: &'ll DIScope,
) -> &'ll DIType {
let (file, line) = self
.source_info
.map(|info| (info.file, info.line))
.unwrap_or_else(|| (unknown_file_metadata(cx), UNKNOWN_LINE_NUMBER));
unsafe {
llvm::LLVMRustDIBuilderCreateVariantMemberType(
DIB(cx),
composite_type_metadata,
self.name.as_ptr().cast(),
self.name.len(),
file,
line,
self.size.bits(),
self.align.bits() as u32,
self.offset.bits(),
self.discriminant.map(|v| cx.const_u64(v)),
self.flags,
self.type_metadata,
)
}
}
}
/// A factory for `MemberDescription`s. It produces a list of member descriptions
/// for some record-like type. `MemberDescriptionFactory`s are used to defer the
/// creation of type member descriptions in order to break cycles arising from
/// recursive type definitions.
enum MemberDescriptionFactory<'ll, 'tcx> {
StructMDF(StructMemberDescriptionFactory<'tcx>),
TupleMDF(TupleMemberDescriptionFactory<'tcx>),
EnumMDF(EnumMemberDescriptionFactory<'ll, 'tcx>),
UnionMDF(UnionMemberDescriptionFactory<'tcx>),
VariantMDF(VariantMemberDescriptionFactory<'tcx>),
}
impl<'ll, 'tcx> MemberDescriptionFactory<'ll, 'tcx> {
fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDescription<'ll>> {
match *self {
StructMDF(ref this) => this.create_member_descriptions(cx),
TupleMDF(ref this) => this.create_member_descriptions(cx),
EnumMDF(ref this) => this.create_member_descriptions(cx),
UnionMDF(ref this) => this.create_member_descriptions(cx),
VariantMDF(ref this) => this.create_member_descriptions(cx),
}
}
}
//=-----------------------------------------------------------------------------
// Structs
//=-----------------------------------------------------------------------------
/// Creates `MemberDescription`s for the fields of a struct.
struct StructMemberDescriptionFactory<'tcx> {
ty: Ty<'tcx>,
variant: &'tcx ty::VariantDef,
}
impl<'tcx> StructMemberDescriptionFactory<'tcx> {
fn create_member_descriptions<'ll>(
&self,
cx: &CodegenCx<'ll, 'tcx>,
) -> Vec<MemberDescription<'ll>> {
let layout = cx.layout_of(self.ty);
self.variant
.fields
.iter()
.enumerate()
.map(|(i, f)| {
let name = if self.variant.ctor_kind == CtorKind::Fn {
format!("__{}", i)
} else {
f.name.to_string()
};
let field = layout.field(cx, i);
MemberDescription {
name,
type_metadata: type_metadata(cx, field.ty),
offset: layout.fields.offset(i),
size: field.size,
align: field.align.abi,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
}
})
.collect()
}
}
fn prepare_struct_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
struct_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
) -> RecursiveTypeDescription<'ll, 'tcx> {
let struct_name = compute_debuginfo_type_name(cx.tcx, struct_type, false);
let (struct_def_id, variant) = match struct_type.kind() {
ty::Adt(def, _) => (def.did, def.non_enum_variant()),
_ => bug!("prepare_struct_metadata on a non-ADT"),
};
let containing_scope = get_namespace_for_item(cx, struct_def_id);
let struct_metadata_stub = create_struct_stub(
cx,
struct_type,
&struct_name,
unique_type_id,
Some(containing_scope),
DIFlags::FlagZero,
);
create_and_register_recursive_type_forward_declaration(
cx,
struct_type,
unique_type_id,
struct_metadata_stub,
struct_metadata_stub,
StructMDF(StructMemberDescriptionFactory { ty: struct_type, variant }),
)
}
//=-----------------------------------------------------------------------------
// 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.
fn closure_saved_names_of_captured_variables(tcx: TyCtxt<'_>, def_id: DefId) -> Vec<String> {
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::<Vec<_>>()
}
/// Creates `MemberDescription`s for the fields of a tuple.
struct TupleMemberDescriptionFactory<'tcx> {
ty: Ty<'tcx>,
component_types: Vec<Ty<'tcx>>,
}
impl<'tcx> TupleMemberDescriptionFactory<'tcx> {
fn create_member_descriptions<'ll>(
&self,
cx: &CodegenCx<'ll, 'tcx>,
) -> Vec<MemberDescription<'ll>> {
let mut capture_names = match *self.ty.kind() {
ty::Generator(def_id, ..) | ty::Closure(def_id, ..) => {
Some(closure_saved_names_of_captured_variables(cx.tcx, def_id).into_iter())
}
_ => None,
};
let layout = cx.layout_of(self.ty);
self.component_types
.iter()
.enumerate()
.map(|(i, &component_type)| {
let (size, align) = cx.size_and_align_of(component_type);
let name = if let Some(names) = capture_names.as_mut() {
names.next().unwrap()
} else {
format!("__{}", i)
};
MemberDescription {
name,
type_metadata: type_metadata(cx, component_type),
offset: layout.fields.offset(i),
size,
align,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
}
})
.collect()
}
}
fn prepare_tuple_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
tuple_type: Ty<'tcx>,
component_types: &[Ty<'tcx>],
unique_type_id: UniqueTypeId,
containing_scope: Option<&'ll DIScope>,
) -> RecursiveTypeDescription<'ll, 'tcx> {
let tuple_name = compute_debuginfo_type_name(cx.tcx, tuple_type, false);
let struct_stub = create_struct_stub(
cx,
tuple_type,
&tuple_name[..],
unique_type_id,
containing_scope,
DIFlags::FlagZero,
);
create_and_register_recursive_type_forward_declaration(
cx,
tuple_type,
unique_type_id,
struct_stub,
struct_stub,
TupleMDF(TupleMemberDescriptionFactory {
ty: tuple_type,
component_types: component_types.to_vec(),
}),
)
}
//=-----------------------------------------------------------------------------
// Unions
//=-----------------------------------------------------------------------------
struct UnionMemberDescriptionFactory<'tcx> {
layout: TyAndLayout<'tcx>,
variant: &'tcx ty::VariantDef,
}
impl<'tcx> UnionMemberDescriptionFactory<'tcx> {
fn create_member_descriptions<'ll>(
&self,
cx: &CodegenCx<'ll, 'tcx>,
) -> Vec<MemberDescription<'ll>> {
self.variant
.fields
.iter()
.enumerate()
.map(|(i, f)| {
let field = self.layout.field(cx, i);
MemberDescription {
name: f.name.to_string(),
type_metadata: type_metadata(cx, field.ty),
offset: Size::ZERO,
size: field.size,
align: field.align.abi,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
}
})
.collect()
}
}
fn prepare_union_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
union_type: Ty<'tcx>,
unique_type_id: UniqueTypeId,
) -> RecursiveTypeDescription<'ll, 'tcx> {
let union_name = compute_debuginfo_type_name(cx.tcx, union_type, false);
let (union_def_id, variant) = match union_type.kind() {
ty::Adt(def, _) => (def.did, def.non_enum_variant()),
_ => bug!("prepare_union_metadata on a non-ADT"),
};
let containing_scope = get_namespace_for_item(cx, union_def_id);
let union_metadata_stub =
create_union_stub(cx, union_type, &union_name, unique_type_id, containing_scope);
create_and_register_recursive_type_forward_declaration(
cx,
union_type,
unique_type_id,
union_metadata_stub,
union_metadata_stub,
UnionMDF(UnionMemberDescriptionFactory { layout: cx.layout_of(union_type), variant }),
)
}
//=-----------------------------------------------------------------------------
// Enums
//=-----------------------------------------------------------------------------
// 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<mir::GeneratorSavedLocal, Option<Symbol>>) {
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)
}
/// Describes the members of an enum value; an enum is described as a union of
/// structs in DWARF. This `MemberDescriptionFactory` provides the description for
/// the members of this union; so for every variant of the given enum, this
/// factory will produce one `MemberDescription` (all with no name and a fixed
/// offset of zero bytes).
struct EnumMemberDescriptionFactory<'ll, 'tcx> {
enum_type: Ty<'tcx>,
layout: TyAndLayout<'tcx>,
tag_type_metadata: Option<&'ll DIType>,
common_members: Vec<Option<&'ll DIType>>,
}
impl<'ll, 'tcx> EnumMemberDescriptionFactory<'ll, 'tcx> {
fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDescription<'ll>> {
let generator_variant_info_data = match *self.enum_type.kind() {
ty::Generator(def_id, ..) => {
Some(generator_layout_and_saved_local_names(cx.tcx, def_id))
}
_ => None,
};
let variant_info_for = |index: VariantIdx| match *self.enum_type.kind() {
ty::Adt(adt, _) => VariantInfo::Adt(&adt.variants[index]),
ty::Generator(def_id, _, _) => {
let (generator_layout, generator_saved_local_names) =
generator_variant_info_data.as_ref().unwrap();
VariantInfo::Generator {
def_id,
generator_layout: *generator_layout,
generator_saved_local_names,
variant_index: index,
}
}
_ => bug!(),
};
// While LLVM supports generating debuginfo for variant types (enums), it doesn't support
// lowering that debuginfo to CodeView records for msvc targets. So if we are targeting
// msvc, then we need to use a different, fallback encoding of the debuginfo.
let fallback = cpp_like_debuginfo(cx.tcx);
// This will always find the metadata in the type map.
let self_metadata = type_metadata(cx, self.enum_type);
match self.layout.variants {
Variants::Single { index } => {
if let ty::Adt(adt, _) = self.enum_type.kind() {
if adt.variants.is_empty() {
return vec![];
}
}
let variant_info = variant_info_for(index);
let (variant_type_metadata, member_description_factory) =
describe_enum_variant(cx, self.layout, variant_info, self_metadata);
let member_descriptions = member_description_factory.create_member_descriptions(cx);
set_members_of_composite_type(
cx,
self.enum_type,
variant_type_metadata,
member_descriptions,
Some(&self.common_members),
);
vec![MemberDescription {
name: variant_info.variant_name(),
type_metadata: variant_type_metadata,
offset: Size::ZERO,
size: self.layout.size,
align: self.layout.align.abi,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: variant_info.source_info(cx),
}]
}
Variants::Multiple {
tag_encoding: TagEncoding::Direct,
tag_field,
ref variants,
..
} => {
let fallback_discr_variant = if fallback {
// For MSVC, we generate a union of structs for each variant and an
// explicit discriminant field roughly equivalent to the following C:
// ```c
// union enum$<{name}> {
// struct {variant 0 name} {
// <variant 0 fields>
// } variant0;
// <other variant structs>
// {name} discriminant;
// }
// ```
// The natvis in `intrinsic.natvis` then matches on `this.discriminant` to
// determine which variant is active and then displays it.
let enum_layout = self.layout;
let offset = enum_layout.fields.offset(tag_field);
let discr_ty = enum_layout.field(cx, tag_field).ty;
let (size, align) = cx.size_and_align_of(discr_ty);
Some(MemberDescription {
name: "discriminant".into(),
type_metadata: self.tag_type_metadata.unwrap(),
offset,
size,
align,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
})
} else {
None
};
variants
.iter_enumerated()
.map(|(i, _)| {
let variant = self.layout.for_variant(cx, i);
let variant_info = variant_info_for(i);
let (variant_type_metadata, member_desc_factory) =
describe_enum_variant(cx, variant, variant_info, self_metadata);
let member_descriptions =
member_desc_factory.create_member_descriptions(cx);
set_members_of_composite_type(
cx,
self.enum_type,
variant_type_metadata,
member_descriptions,
Some(&self.common_members),
);
MemberDescription {
name: if fallback {
format!("variant{}", i.as_u32())
} else {
variant_info.variant_name()
},
type_metadata: variant_type_metadata,
offset: Size::ZERO,
size: self.layout.size,
align: self.layout.align.abi,
flags: DIFlags::FlagZero,
discriminant: Some(
self.layout.ty.discriminant_for_variant(cx.tcx, i).unwrap().val
as u64,
),
source_info: variant_info.source_info(cx),
}
})
.chain(fallback_discr_variant.into_iter())
.collect()
}
Variants::Multiple {
tag_encoding:
TagEncoding::Niche { ref niche_variants, niche_start, dataful_variant },
tag,
ref variants,
tag_field,
} => {
let calculate_niche_value = |i: VariantIdx| {
if i == dataful_variant {
None
} else {
let value = (i.as_u32() as u128)
.wrapping_sub(niche_variants.start().as_u32() as u128)
.wrapping_add(niche_start);
let value = tag.value.size(cx).truncate(value);
// NOTE(eddyb) do *NOT* remove this assert, until
// we pass the full 128-bit value to LLVM, otherwise
// truncation will be silent and remain undetected.
assert_eq!(value as u64 as u128, value);
Some(value as u64)
}
};
// For MSVC, we will generate a union of two fields, one for the dataful variant
// and one that just points to the discriminant. We also create an enum that
// contains tag values for the non-dataful variants and make the discriminant field
// that type. We then use natvis to render the enum type correctly in Windbg/VS.
// This will generate debuginfo roughly equivalent to the following C:
// ```c
// union enum$<{name}, {min niche}, {max niche}, {dataful variant name}> {
// struct <dataful variant name> {
// <fields in dataful variant>
// } dataful_variant;
// enum Discriminant$ {
// <non-dataful variants>
// } discriminant;
// }
// ```
// The natvis in `intrinsic.natvis` matches on the type name `enum$<*, *, *, *>`
// and evaluates `this.discriminant`. If the value is between the min niche and max
// niche, then the enum is in the dataful variant and `this.dataful_variant` is
// rendered. Otherwise, the enum is in one of the non-dataful variants. In that
// case, we just need to render the name of the `this.discriminant` enum.
if fallback {
let dataful_variant_layout = self.layout.for_variant(cx, dataful_variant);
let mut discr_enum_ty = tag.value.to_ty(cx.tcx);
// If the niche is the NULL value of a reference, then `discr_enum_ty` will be a RawPtr.
// CodeView doesn't know what to do with enums whose base type is a pointer so we fix this up
// to just be `usize`.
if let ty::RawPtr(_) = discr_enum_ty.kind() {
discr_enum_ty = cx.tcx.types.usize;
}
let tags: Vec<_> = variants
.iter_enumerated()
.filter_map(|(variant_idx, _)| {
calculate_niche_value(variant_idx).map(|tag| {
let variant = variant_info_for(variant_idx);
let name = variant.variant_name();
Some(unsafe {
llvm::LLVMRustDIBuilderCreateEnumerator(
DIB(cx),
name.as_ptr().cast(),
name.len(),
tag as i64,
!discr_enum_ty.is_signed(),
)
})
})
})
.collect();
let discr_enum = unsafe {
llvm::LLVMRustDIBuilderCreateEnumerationType(
DIB(cx),
self_metadata,
"Discriminant$".as_ptr().cast(),
"Discriminant$".len(),
unknown_file_metadata(cx),
UNKNOWN_LINE_NUMBER,
tag.value.size(cx).bits(),
tag.value.align(cx).abi.bits() as u32,
create_DIArray(DIB(cx), &tags),
type_metadata(cx, discr_enum_ty),
true,
)
};
let variant_info = variant_info_for(dataful_variant);
let (variant_type_metadata, member_desc_factory) = describe_enum_variant(
cx,
dataful_variant_layout,
variant_info,
self_metadata,
);
let member_descriptions = member_desc_factory.create_member_descriptions(cx);
set_members_of_composite_type(
cx,
self.enum_type,
variant_type_metadata,
member_descriptions,
Some(&self.common_members),
);
let (size, align) =
cx.size_and_align_of(dataful_variant_layout.field(cx, tag_field).ty);
vec![
MemberDescription {
// Name the dataful variant so that we can identify it for natvis
name: "dataful_variant".to_string(),
type_metadata: variant_type_metadata,
offset: Size::ZERO,
size: self.layout.size,
align: self.layout.align.abi,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: variant_info.source_info(cx),
},
MemberDescription {
name: "discriminant".into(),
type_metadata: discr_enum,
offset: dataful_variant_layout.fields.offset(tag_field),
size,
align,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
},
]
} else {
variants
.iter_enumerated()
.map(|(i, _)| {
let variant = self.layout.for_variant(cx, i);
let variant_info = variant_info_for(i);
let (variant_type_metadata, member_desc_factory) =
describe_enum_variant(cx, variant, variant_info, self_metadata);
let member_descriptions =
member_desc_factory.create_member_descriptions(cx);
set_members_of_composite_type(
cx,
self.enum_type,
variant_type_metadata,
member_descriptions,
Some(&self.common_members),
);
let niche_value = calculate_niche_value(i);
MemberDescription {
name: variant_info.variant_name(),
type_metadata: variant_type_metadata,
offset: Size::ZERO,
size: self.layout.size,
align: self.layout.align.abi,
flags: DIFlags::FlagZero,
discriminant: niche_value,
source_info: variant_info.source_info(cx),
}
})
.collect()
}
}
}
}
}
// Creates `MemberDescription`s for the fields of a single enum variant.
struct VariantMemberDescriptionFactory<'tcx> {
/// Cloned from the `layout::Struct` describing the variant.
offsets: Vec<Size>,
args: Vec<(String, Ty<'tcx>)>,
}
impl<'tcx> VariantMemberDescriptionFactory<'tcx> {
fn create_member_descriptions<'ll>(
&self,
cx: &CodegenCx<'ll, 'tcx>,
) -> Vec<MemberDescription<'ll>> {
self.args
.iter()
.enumerate()
.map(|(i, &(ref name, ty))| {
let (size, align) = cx.size_and_align_of(ty);
MemberDescription {
name: name.to_string(),
type_metadata: type_metadata(cx, ty),
offset: self.offsets[i],
size,
align,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
}
})
.collect()
}
}
#[derive(Copy, Clone)]
enum VariantInfo<'a, 'tcx> {
Adt(&'tcx ty::VariantDef),
Generator {
def_id: DefId,
generator_layout: &'tcx GeneratorLayout<'tcx>,
generator_saved_local_names: &'a IndexVec<mir::GeneratorSavedLocal, Option<Symbol>>,
variant_index: VariantIdx,
},
}
impl<'tcx> VariantInfo<'_, 'tcx> {
fn map_struct_name<R>(&self, f: impl FnOnce(&str) -> R) -> R {
match self {
VariantInfo::Adt(variant) => f(variant.name.as_str()),
VariantInfo::Generator { variant_index, .. } => {
f(&GeneratorSubsts::variant_name(*variant_index))
}
}
}
fn variant_name(&self) -> String {
match self {
VariantInfo::Adt(variant) => variant.name.to_string(),
VariantInfo::Generator { variant_index, .. } => {
// Since GDB currently prints out the raw discriminant along
// with every variant, make each variant name be just the value
// of the discriminant. The struct name for the variant includes
// the actual variant description.
format!("{}", variant_index.as_usize())
}
}
}
fn field_name(&self, i: usize) -> String {
let field_name = match *self {
VariantInfo::Adt(variant) if variant.ctor_kind != CtorKind::Fn => {
Some(variant.fields[i].name)
}
VariantInfo::Generator {
generator_layout,
generator_saved_local_names,
variant_index,
..
} => {
generator_saved_local_names
[generator_layout.variant_fields[variant_index][i.into()]]
}
_ => None,
};
field_name.map(|name| name.to_string()).unwrap_or_else(|| format!("__{}", i))
}
fn source_info<'ll>(&self, cx: &CodegenCx<'ll, 'tcx>) -> Option<SourceInfo<'ll>> {
if let VariantInfo::Generator { def_id, variant_index, .. } = self {
let span =
cx.tcx.generator_layout(*def_id).unwrap().variant_source_info[*variant_index].span;
if !span.is_dummy() {
let loc = cx.lookup_debug_loc(span.lo());
return Some(SourceInfo { file: file_metadata(cx, &loc.file), line: loc.line });
}
}
None
}
}
/// Returns a tuple of (1) `type_metadata_stub` of the variant, (2) a
/// `MemberDescriptionFactory` for producing the descriptions of the
/// fields of the variant. This is a rudimentary version of a full
/// `RecursiveTypeDescription`.
fn describe_enum_variant<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
layout: layout::TyAndLayout<'tcx>,
variant: VariantInfo<'_, 'tcx>,
containing_scope: &'ll DIScope,
) -> (&'ll DICompositeType, MemberDescriptionFactory<'ll, 'tcx>) {
let metadata_stub = variant.map_struct_name(|variant_name| {
let unique_type_id = debug_context(cx)
.type_map
.borrow_mut()
.get_unique_type_id_of_enum_variant(cx, layout.ty, variant_name);
create_struct_stub(
cx,
layout.ty,
variant_name,
unique_type_id,
Some(containing_scope),
DIFlags::FlagZero,
)
});
let offsets = (0..layout.fields.count()).map(|i| layout.fields.offset(i)).collect();
let args = (0..layout.fields.count())
.map(|i| (variant.field_name(i), layout.field(cx, i).ty))
.collect();
let member_description_factory = VariantMDF(VariantMemberDescriptionFactory { offsets, args });
(metadata_stub, member_description_factory)
}
fn prepare_enum_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
enum_type: Ty<'tcx>,
enum_def_id: DefId,
unique_type_id: UniqueTypeId,
outer_field_tys: Vec<Ty<'tcx>>,
) -> RecursiveTypeDescription<'ll, 'tcx> {
let tcx = cx.tcx;
let enum_name = compute_debuginfo_type_name(tcx, enum_type, false);
let containing_scope = get_namespace_for_item(cx, enum_def_id);
// FIXME: This should emit actual file metadata for the enum, but we
// currently can't get the necessary information when it comes to types
// imported from other crates. Formerly we violated the ODR when performing
// LTO because we emitted debuginfo for the same type with varying file
// metadata, so as a workaround we pretend that the type comes from
// <unknown>
let file_metadata = unknown_file_metadata(cx);
let discriminant_type_metadata = |discr: Primitive| {
let enumerators_metadata: Vec<_> = match enum_type.kind() {
ty::Adt(def, _) => iter::zip(def.discriminants(tcx), &def.variants)
.map(|((_, discr), v)| {
let name = v.name.as_str();
let is_unsigned = match discr.ty.kind() {
ty::Int(_) => false,
ty::Uint(_) => true,
_ => bug!("non integer discriminant"),
};
unsafe {
Some(llvm::LLVMRustDIBuilderCreateEnumerator(
DIB(cx),
name.as_ptr().cast(),
name.len(),
// FIXME: what if enumeration has i128 discriminant?
discr.val as i64,
is_unsigned,
))
}
})
.collect(),
ty::Generator(_, substs, _) => substs
.as_generator()
.variant_range(enum_def_id, tcx)
.map(|variant_index| {
debug_assert_eq!(tcx.types.u32, substs.as_generator().discr_ty(tcx));
let name = GeneratorSubsts::variant_name(variant_index);
unsafe {
Some(llvm::LLVMRustDIBuilderCreateEnumerator(
DIB(cx),
name.as_ptr().cast(),
name.len(),
// Generators use u32 as discriminant type, verified above.
variant_index.as_u32().into(),
true, // IsUnsigned
))
}
})
.collect(),
_ => bug!(),
};
let disr_type_key = (enum_def_id, discr);
let cached_discriminant_type_metadata =
debug_context(cx).created_enum_disr_types.borrow().get(&disr_type_key).cloned();
match cached_discriminant_type_metadata {
Some(discriminant_type_metadata) => discriminant_type_metadata,
None => {
let (discriminant_size, discriminant_align) = (discr.size(cx), discr.align(cx));
let discriminant_base_type_metadata = type_metadata(cx, discr.to_ty(tcx));
let item_name;
let discriminant_name = match enum_type.kind() {
ty::Adt(..) => {
item_name = tcx.item_name(enum_def_id);
item_name.as_str()
}
ty::Generator(..) => enum_name.as_str(),
_ => bug!(),
};
let discriminant_type_metadata = unsafe {
llvm::LLVMRustDIBuilderCreateEnumerationType(
DIB(cx),
containing_scope,
discriminant_name.as_ptr().cast(),
discriminant_name.len(),
file_metadata,
UNKNOWN_LINE_NUMBER,
discriminant_size.bits(),
discriminant_align.abi.bits() as u32,
create_DIArray(DIB(cx), &enumerators_metadata),
discriminant_base_type_metadata,
true,
)
};
debug_context(cx)
.created_enum_disr_types
.borrow_mut()
.insert(disr_type_key, discriminant_type_metadata);
discriminant_type_metadata
}
}
};
let layout = cx.layout_of(enum_type);
if let (Abi::Scalar(_), Variants::Multiple { tag_encoding: TagEncoding::Direct, tag, .. }) =
(layout.abi, &layout.variants)
{
return FinalMetadata(discriminant_type_metadata(tag.value));
}
// While LLVM supports generating debuginfo for variant types (enums), it doesn't support
// lowering that debuginfo to CodeView records for msvc targets. So if we are targeting
// msvc, then we need to use a different encoding of the debuginfo.
if cpp_like_debuginfo(tcx) {
let discriminant_type_metadata = match layout.variants {
Variants::Single { .. } => None,
Variants::Multiple { tag_encoding: TagEncoding::Niche { .. }, tag, .. }
| Variants::Multiple { tag_encoding: TagEncoding::Direct, tag, .. } => {
Some(discriminant_type_metadata(tag.value))
}
};
let enum_metadata = {
let type_map = debug_context(cx).type_map.borrow();
let unique_type_id_str = type_map.get_unique_type_id_as_string(unique_type_id);
unsafe {
llvm::LLVMRustDIBuilderCreateUnionType(
DIB(cx),
None,
enum_name.as_ptr().cast(),
enum_name.len(),
file_metadata,
UNKNOWN_LINE_NUMBER,
layout.size.bits(),
layout.align.abi.bits() as u32,
DIFlags::FlagZero,
None,
0, // RuntimeLang
unique_type_id_str.as_ptr().cast(),
unique_type_id_str.len(),
)
}
};
return create_and_register_recursive_type_forward_declaration(
cx,
enum_type,
unique_type_id,
enum_metadata,
enum_metadata,
EnumMDF(EnumMemberDescriptionFactory {
enum_type,
layout,
tag_type_metadata: discriminant_type_metadata,
common_members: vec![],
}),
);
}
let discriminator_name = match enum_type.kind() {
ty::Generator(..) => "__state",
_ => "",
};
let discriminator_metadata = match layout.variants {
// A single-variant enum has no discriminant.
Variants::Single { .. } => None,
Variants::Multiple { tag_encoding: TagEncoding::Niche { .. }, tag, tag_field, .. } => {
// Find the integer type of the correct size.
let size = tag.value.size(cx);
let align = tag.value.align(cx);
let tag_type = match tag.value {
Int(t, _) => t,
F32 => Integer::I32,
F64 => Integer::I64,
Pointer => cx.data_layout().ptr_sized_integer(),
}
.to_ty(cx.tcx, false);
let tag_metadata = basic_type_metadata(cx, tag_type);
unsafe {
Some(llvm::LLVMRustDIBuilderCreateMemberType(
DIB(cx),
containing_scope,
discriminator_name.as_ptr().cast(),
discriminator_name.len(),
file_metadata,
UNKNOWN_LINE_NUMBER,
size.bits(),
align.abi.bits() as u32,
layout.fields.offset(tag_field).bits(),
DIFlags::FlagArtificial,
tag_metadata,
))
}
}
Variants::Multiple { tag_encoding: TagEncoding::Direct, tag, tag_field, .. } => {
let discr_type = tag.value.to_ty(cx.tcx);
let (size, align) = cx.size_and_align_of(discr_type);
let discr_metadata = basic_type_metadata(cx, discr_type);
unsafe {
Some(llvm::LLVMRustDIBuilderCreateMemberType(
DIB(cx),
containing_scope,
discriminator_name.as_ptr().cast(),
discriminator_name.len(),
file_metadata,
UNKNOWN_LINE_NUMBER,
size.bits(),
align.bits() as u32,
layout.fields.offset(tag_field).bits(),
DIFlags::FlagArtificial,
discr_metadata,
))
}
}
};
let outer_fields = match layout.variants {
Variants::Single { .. } => vec![],
Variants::Multiple { .. } => {
let tuple_mdf =
TupleMemberDescriptionFactory { ty: enum_type, component_types: outer_field_tys };
tuple_mdf
.create_member_descriptions(cx)
.into_iter()
.map(|desc| Some(desc.into_metadata(cx, containing_scope)))
.collect()
}
};
let variant_part_unique_type_id_str = debug_context(cx)
.type_map
.borrow_mut()
.get_unique_type_id_str_of_enum_variant_part(unique_type_id);
let empty_array = create_DIArray(DIB(cx), &[]);
let name = "";
let variant_part = unsafe {
llvm::LLVMRustDIBuilderCreateVariantPart(
DIB(cx),
containing_scope,
name.as_ptr().cast(),
name.len(),
file_metadata,
UNKNOWN_LINE_NUMBER,
layout.size.bits(),
layout.align.abi.bits() as u32,
DIFlags::FlagZero,
discriminator_metadata,
empty_array,
variant_part_unique_type_id_str.as_ptr().cast(),
variant_part_unique_type_id_str.len(),
)
};
let struct_wrapper = {
// The variant part must be wrapped in a struct according to DWARF.
// All fields except the discriminant (including `outer_fields`)
// should be put into structures inside the variant part, which gives
// an equivalent layout but offers us much better integration with
// debuggers.
let type_array = create_DIArray(DIB(cx), &[Some(variant_part)]);
let type_map = debug_context(cx).type_map.borrow();
let unique_type_id_str = type_map.get_unique_type_id_as_string(unique_type_id);
unsafe {
llvm::LLVMRustDIBuilderCreateStructType(
DIB(cx),
Some(containing_scope),
enum_name.as_ptr().cast(),
enum_name.len(),
file_metadata,
UNKNOWN_LINE_NUMBER,
layout.size.bits(),
layout.align.abi.bits() as u32,
DIFlags::FlagZero,
None,
type_array,
0,
None,
unique_type_id_str.as_ptr().cast(),
unique_type_id_str.len(),
)
}
};
create_and_register_recursive_type_forward_declaration(
cx,
enum_type,
unique_type_id,
struct_wrapper,
variant_part,
EnumMDF(EnumMemberDescriptionFactory {
enum_type,
layout,
tag_type_metadata: None,
common_members: outer_fields,
}),
)
}
/// Creates debug information for a composite type, that is, anything that
/// results in a LLVM struct.
///
/// Examples of Rust types to use this are: structs, tuples, boxes, vecs, and enums.
fn composite_type_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
composite_type: Ty<'tcx>,
composite_type_name: &str,
composite_type_unique_id: UniqueTypeId,
member_descriptions: Vec<MemberDescription<'ll>>,
containing_scope: Option<&'ll DIScope>,
) -> &'ll DICompositeType {
// Create the (empty) struct metadata node ...
let composite_type_metadata = create_struct_stub(
cx,
composite_type,
composite_type_name,
composite_type_unique_id,
containing_scope,
DIFlags::FlagZero,
);
// ... and immediately create and add the member descriptions.
set_members_of_composite_type(
cx,
composite_type,
composite_type_metadata,
member_descriptions,
None,
);
composite_type_metadata
}
fn set_members_of_composite_type<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
composite_type: Ty<'tcx>,
composite_type_metadata: &'ll DICompositeType,
member_descriptions: Vec<MemberDescription<'ll>>,
common_members: Option<&Vec<Option<&'ll DIType>>>,
) {
// In some rare cases LLVM metadata uniquing would lead to an existing type
// description being used instead of a new one created in
// create_struct_stub. This would cause a hard to trace assertion in
// DICompositeType::SetTypeArray(). The following check makes sure that we
// get a better error message if this should happen again due to some
// regression.
{
let mut composite_types_completed =
debug_context(cx).composite_types_completed.borrow_mut();
if !composite_types_completed.insert(composite_type_metadata) {
bug!(
"debuginfo::set_members_of_composite_type() - \
Already completed forward declaration re-encountered."
);
}
}
let mut member_metadata: Vec<_> = member_descriptions
.into_iter()
.map(|desc| Some(desc.into_metadata(cx, composite_type_metadata)))
.collect();
if let Some(other_members) = common_members {
member_metadata.extend(other_members.iter());
}
let type_params = compute_type_parameters(cx, composite_type);
unsafe {
let type_array = create_DIArray(DIB(cx), &member_metadata);
llvm::LLVMRustDICompositeTypeReplaceArrays(
DIB(cx),
composite_type_metadata,
Some(type_array),
Some(type_params),
);
}
}
/// Computes the type parameters for a type, if any, for the given metadata.
fn compute_type_parameters<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>) -> &'ll DIArray {
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: Vec<_> = 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_metadata = type_metadata(cx, actual_type);
let name = name.as_str();
Some(unsafe {
Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
DIB(cx),
None,
name.as_ptr().cast(),
name.len(),
actual_type_metadata,
))
})
} else {
None
}
})
.collect();
return create_DIArray(DIB(cx), &template_params);
}
}
return create_DIArray(DIB(cx), &[]);
fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
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
}
}
/// A convenience wrapper around `LLVMRustDIBuilderCreateStructType()`. Does not do
/// any caching, does not add any fields to the struct. This can be done later
/// with `set_members_of_composite_type()`.
fn create_struct_stub<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
struct_type: Ty<'tcx>,
struct_type_name: &str,
unique_type_id: UniqueTypeId,
containing_scope: Option<&'ll DIScope>,
flags: DIFlags,
) -> &'ll DICompositeType {
let (struct_size, struct_align) = cx.size_and_align_of(struct_type);
let type_map = debug_context(cx).type_map.borrow();
let unique_type_id = type_map.get_unique_type_id_as_string(unique_type_id);
let metadata_stub = unsafe {
// `LLVMRustDIBuilderCreateStructType()` wants an empty array. A null
// pointer will lead to hard to trace and debug LLVM assertions
// later on in `llvm/lib/IR/Value.cpp`.
let empty_array = create_DIArray(DIB(cx), &[]);
llvm::LLVMRustDIBuilderCreateStructType(
DIB(cx),
containing_scope,
struct_type_name.as_ptr().cast(),
struct_type_name.len(),
unknown_file_metadata(cx),
UNKNOWN_LINE_NUMBER,
struct_size.bits(),
struct_align.bits() as u32,
flags,
None,
empty_array,
0,
None,
unique_type_id.as_ptr().cast(),
unique_type_id.len(),
)
};
metadata_stub
}
fn create_union_stub<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
union_type: Ty<'tcx>,
union_type_name: &str,
unique_type_id: UniqueTypeId,
containing_scope: &'ll DIScope,
) -> &'ll DICompositeType {
let (union_size, union_align) = cx.size_and_align_of(union_type);
let type_map = debug_context(cx).type_map.borrow();
let unique_type_id = type_map.get_unique_type_id_as_string(unique_type_id);
let metadata_stub = unsafe {
// `LLVMRustDIBuilderCreateUnionType()` wants an empty array. A null
// pointer will lead to hard to trace and debug LLVM assertions
// later on in `llvm/lib/IR/Value.cpp`.
let empty_array = create_DIArray(DIB(cx), &[]);
llvm::LLVMRustDIBuilderCreateUnionType(
DIB(cx),
Some(containing_scope),
union_type_name.as_ptr().cast(),
union_type_name.len(),
unknown_file_metadata(cx),
UNKNOWN_LINE_NUMBER,
union_size.bits(),
union_align.bits() as u32,
DIFlags::FlagZero,
Some(empty_array),
0, // RuntimeLang
unique_type_id.as_ptr().cast(),
unique_type_id.len(),
)
};
metadata_stub
}
/// Creates debug information for the given global variable.
///
/// Adds the created metadata nodes directly to the crate's IR.
pub fn create_global_var_metadata<'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_metadata = type_metadata(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_metadata,
is_local_to_unit,
global,
None,
global_align.bytes() as u32,
);
}
}
/// Generates LLVM debuginfo for a vtable.
fn vtable_type_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
ty: Ty<'tcx>,
poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> &'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 {
COMMON_VTABLE_ENTRIES
};
// FIXME: We describe the vtable as an array of *const () pointers. The length of the array is
// correct - but we could create a more accurate description, e.g. by describing it
// as a struct where each field has a name that corresponds to the name of the method
// it points to.
// However, this is not entirely straightforward because there might be multiple
// methods with the same name if the vtable is for multiple traits. So for now we keep
// things simple instead of adding some ad-hoc disambiguation scheme.
let vtable_type = tcx.mk_array(tcx.mk_imm_ptr(tcx.types.unit), vtable_entries.len() as u64);
type_metadata(cx, vtable_type)
}
/// 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_metadata<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
ty: Ty<'tcx>,
poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
vtable: &'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 vtable_name = compute_debuginfo_vtable_name(cx.tcx, ty, poly_trait_ref);
let vtable_type = vtable_type_metadata(cx, ty, poly_trait_ref);
unsafe {
let linkage_name = "";
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,
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) }
}
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