diff options
Diffstat (limited to 'compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs')
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs b/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs new file mode 100644 index 000000000..693092ba5 --- /dev/null +++ b/compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs @@ -0,0 +1,357 @@ +//! Handling of everything related to debuginfo. + +mod emit; +mod line_info; +mod object; +mod unwind; + +use crate::prelude::*; + +use rustc_index::vec::IndexVec; + +use cranelift_codegen::entity::EntityRef; +use cranelift_codegen::ir::{Endianness, LabelValueLoc, ValueLabel}; +use cranelift_codegen::isa::TargetIsa; +use cranelift_codegen::ValueLocRange; + +use gimli::write::{ + Address, AttributeValue, DwarfUnit, Expression, LineProgram, LineString, Location, + LocationList, Range, RangeList, UnitEntryId, +}; +use gimli::{Encoding, Format, LineEncoding, RunTimeEndian, X86_64}; + +pub(crate) use emit::{DebugReloc, DebugRelocName}; +pub(crate) use unwind::UnwindContext; + +pub(crate) struct DebugContext<'tcx> { + tcx: TyCtxt<'tcx>, + + endian: RunTimeEndian, + + dwarf: DwarfUnit, + unit_range_list: RangeList, + + types: FxHashMap<Ty<'tcx>, UnitEntryId>, +} + +impl<'tcx> DebugContext<'tcx> { + pub(crate) fn new(tcx: TyCtxt<'tcx>, isa: &dyn TargetIsa) -> Self { + let encoding = Encoding { + format: Format::Dwarf32, + // FIXME this should be configurable + // macOS doesn't seem to support DWARF > 3 + // 5 version is required for md5 file hash + version: if tcx.sess.target.is_like_osx { + 3 + } else { + // FIXME change to version 5 once the gdb and lldb shipping with the latest debian + // support it. + 4 + }, + address_size: isa.frontend_config().pointer_bytes(), + }; + + let endian = match isa.endianness() { + Endianness::Little => RunTimeEndian::Little, + Endianness::Big => RunTimeEndian::Big, + }; + + let mut dwarf = DwarfUnit::new(encoding); + + let producer = format!( + "cg_clif (rustc {}, cranelift {})", + rustc_interface::util::version_str().unwrap_or("unknown version"), + cranelift_codegen::VERSION, + ); + let comp_dir = tcx + .sess + .opts + .working_dir + .to_string_lossy(FileNameDisplayPreference::Remapped) + .into_owned(); + let (name, file_info) = match tcx.sess.local_crate_source_file.clone() { + Some(path) => { + let name = path.to_string_lossy().into_owned(); + (name, None) + } + None => (tcx.crate_name(LOCAL_CRATE).to_string(), None), + }; + + let mut line_program = LineProgram::new( + encoding, + LineEncoding::default(), + LineString::new(comp_dir.as_bytes(), encoding, &mut dwarf.line_strings), + LineString::new(name.as_bytes(), encoding, &mut dwarf.line_strings), + file_info, + ); + line_program.file_has_md5 = file_info.is_some(); + + dwarf.unit.line_program = line_program; + + { + let name = dwarf.strings.add(name); + let comp_dir = dwarf.strings.add(comp_dir); + + let root = dwarf.unit.root(); + let root = dwarf.unit.get_mut(root); + root.set(gimli::DW_AT_producer, AttributeValue::StringRef(dwarf.strings.add(producer))); + root.set(gimli::DW_AT_language, AttributeValue::Language(gimli::DW_LANG_Rust)); + root.set(gimli::DW_AT_name, AttributeValue::StringRef(name)); + root.set(gimli::DW_AT_comp_dir, AttributeValue::StringRef(comp_dir)); + root.set(gimli::DW_AT_low_pc, AttributeValue::Address(Address::Constant(0))); + } + + DebugContext { + tcx, + + endian, + + dwarf, + unit_range_list: RangeList(Vec::new()), + + types: FxHashMap::default(), + } + } + + fn dwarf_ty(&mut self, ty: Ty<'tcx>) -> UnitEntryId { + if let Some(type_id) = self.types.get(&ty) { + return *type_id; + } + + let new_entry = |dwarf: &mut DwarfUnit, tag| dwarf.unit.add(dwarf.unit.root(), tag); + + let primitive = |dwarf: &mut DwarfUnit, ate| { + let type_id = new_entry(dwarf, gimli::DW_TAG_base_type); + let type_entry = dwarf.unit.get_mut(type_id); + type_entry.set(gimli::DW_AT_encoding, AttributeValue::Encoding(ate)); + type_id + }; + + let name = format!("{}", ty); + let layout = self.tcx.layout_of(ParamEnv::reveal_all().and(ty)).unwrap(); + + let type_id = match ty.kind() { + ty::Bool => primitive(&mut self.dwarf, gimli::DW_ATE_boolean), + ty::Char => primitive(&mut self.dwarf, gimli::DW_ATE_UTF), + ty::Uint(_) => primitive(&mut self.dwarf, gimli::DW_ATE_unsigned), + ty::Int(_) => primitive(&mut self.dwarf, gimli::DW_ATE_signed), + ty::Float(_) => primitive(&mut self.dwarf, gimli::DW_ATE_float), + ty::Ref(_, pointee_ty, _mutbl) + | ty::RawPtr(ty::TypeAndMut { ty: pointee_ty, mutbl: _mutbl }) => { + let type_id = new_entry(&mut self.dwarf, gimli::DW_TAG_pointer_type); + + // Ensure that type is inserted before recursing to avoid duplicates + self.types.insert(ty, type_id); + + let pointee = self.dwarf_ty(*pointee_ty); + + let type_entry = self.dwarf.unit.get_mut(type_id); + + //type_entry.set(gimli::DW_AT_mutable, AttributeValue::Flag(mutbl == rustc_hir::Mutability::Mut)); + type_entry.set(gimli::DW_AT_type, AttributeValue::UnitRef(pointee)); + + type_id + } + ty::Adt(adt_def, _substs) if adt_def.is_struct() && !layout.is_unsized() => { + let type_id = new_entry(&mut self.dwarf, gimli::DW_TAG_structure_type); + + // Ensure that type is inserted before recursing to avoid duplicates + self.types.insert(ty, type_id); + + let variant = adt_def.non_enum_variant(); + + for (field_idx, field_def) in variant.fields.iter().enumerate() { + let field_offset = layout.fields.offset(field_idx); + let field_layout = layout.field( + &layout::LayoutCx { tcx: self.tcx, param_env: ParamEnv::reveal_all() }, + field_idx, + ); + + let field_type = self.dwarf_ty(field_layout.ty); + + let field_id = self.dwarf.unit.add(type_id, gimli::DW_TAG_member); + let field_entry = self.dwarf.unit.get_mut(field_id); + + field_entry.set( + gimli::DW_AT_name, + AttributeValue::String(field_def.name.as_str().to_string().into_bytes()), + ); + field_entry.set( + gimli::DW_AT_data_member_location, + AttributeValue::Udata(field_offset.bytes()), + ); + field_entry.set(gimli::DW_AT_type, AttributeValue::UnitRef(field_type)); + } + + type_id + } + _ => new_entry(&mut self.dwarf, gimli::DW_TAG_structure_type), + }; + + let type_entry = self.dwarf.unit.get_mut(type_id); + + type_entry.set(gimli::DW_AT_name, AttributeValue::String(name.into_bytes())); + type_entry.set(gimli::DW_AT_byte_size, AttributeValue::Udata(layout.size.bytes())); + + self.types.insert(ty, type_id); + + type_id + } + + fn define_local(&mut self, scope: UnitEntryId, name: String, ty: Ty<'tcx>) -> UnitEntryId { + let dw_ty = self.dwarf_ty(ty); + + let var_id = self.dwarf.unit.add(scope, gimli::DW_TAG_variable); + let var_entry = self.dwarf.unit.get_mut(var_id); + + var_entry.set(gimli::DW_AT_name, AttributeValue::String(name.into_bytes())); + var_entry.set(gimli::DW_AT_type, AttributeValue::UnitRef(dw_ty)); + + var_id + } + + pub(crate) fn define_function( + &mut self, + instance: Instance<'tcx>, + func_id: FuncId, + name: &str, + isa: &dyn TargetIsa, + context: &Context, + source_info_set: &indexmap::IndexSet<SourceInfo>, + local_map: IndexVec<mir::Local, CPlace<'tcx>>, + ) { + let symbol = func_id.as_u32() as usize; + let mir = self.tcx.instance_mir(instance.def); + + // FIXME: add to appropriate scope instead of root + let scope = self.dwarf.unit.root(); + + let entry_id = self.dwarf.unit.add(scope, gimli::DW_TAG_subprogram); + let entry = self.dwarf.unit.get_mut(entry_id); + let name_id = self.dwarf.strings.add(name); + // Gdb requires DW_AT_name. Otherwise the DW_TAG_subprogram is skipped. + entry.set(gimli::DW_AT_name, AttributeValue::StringRef(name_id)); + entry.set(gimli::DW_AT_linkage_name, AttributeValue::StringRef(name_id)); + + let end = self.create_debug_lines(symbol, entry_id, context, mir.span, source_info_set); + + self.unit_range_list.0.push(Range::StartLength { + begin: Address::Symbol { symbol, addend: 0 }, + length: u64::from(end), + }); + + let func_entry = self.dwarf.unit.get_mut(entry_id); + // Gdb requires both DW_AT_low_pc and DW_AT_high_pc. Otherwise the DW_TAG_subprogram is skipped. + func_entry.set( + gimli::DW_AT_low_pc, + AttributeValue::Address(Address::Symbol { symbol, addend: 0 }), + ); + // Using Udata for DW_AT_high_pc requires at least DWARF4 + func_entry.set(gimli::DW_AT_high_pc, AttributeValue::Udata(u64::from(end))); + + // FIXME make it more reliable and implement scopes before re-enabling this. + if false { + let value_labels_ranges = std::collections::HashMap::new(); // FIXME + + for (local, _local_decl) in mir.local_decls.iter_enumerated() { + let ty = self.tcx.subst_and_normalize_erasing_regions( + instance.substs, + ty::ParamEnv::reveal_all(), + mir.local_decls[local].ty, + ); + let var_id = self.define_local(entry_id, format!("{:?}", local), ty); + + let location = place_location( + self, + isa, + symbol, + &local_map, + &value_labels_ranges, + Place { local, projection: ty::List::empty() }, + ); + + let var_entry = self.dwarf.unit.get_mut(var_id); + var_entry.set(gimli::DW_AT_location, location); + } + } + + // FIXME create locals for all entries in mir.var_debug_info + } +} + +fn place_location<'tcx>( + debug_context: &mut DebugContext<'tcx>, + isa: &dyn TargetIsa, + symbol: usize, + local_map: &IndexVec<mir::Local, CPlace<'tcx>>, + #[allow(rustc::default_hash_types)] value_labels_ranges: &std::collections::HashMap< + ValueLabel, + Vec<ValueLocRange>, + >, + place: Place<'tcx>, +) -> AttributeValue { + assert!(place.projection.is_empty()); // FIXME implement them + + match local_map[place.local].inner() { + CPlaceInner::Var(_local, var) => { + let value_label = cranelift_codegen::ir::ValueLabel::new(var.index()); + if let Some(value_loc_ranges) = value_labels_ranges.get(&value_label) { + let loc_list = LocationList( + value_loc_ranges + .iter() + .map(|value_loc_range| Location::StartEnd { + begin: Address::Symbol { + symbol, + addend: i64::from(value_loc_range.start), + }, + end: Address::Symbol { symbol, addend: i64::from(value_loc_range.end) }, + data: translate_loc(isa, value_loc_range.loc).unwrap(), + }) + .collect(), + ); + let loc_list_id = debug_context.dwarf.unit.locations.add(loc_list); + + AttributeValue::LocationListRef(loc_list_id) + } else { + // FIXME set value labels for unused locals + + AttributeValue::Exprloc(Expression::new()) + } + } + CPlaceInner::VarPair(_, _, _) => { + // FIXME implement this + + AttributeValue::Exprloc(Expression::new()) + } + CPlaceInner::VarLane(_, _, _) => { + // FIXME implement this + + AttributeValue::Exprloc(Expression::new()) + } + CPlaceInner::Addr(_, _) => { + // FIXME implement this (used by arguments and returns) + + AttributeValue::Exprloc(Expression::new()) + + // For PointerBase::Stack: + //AttributeValue::Exprloc(translate_loc(ValueLoc::Stack(*stack_slot)).unwrap()) + } + } +} + +// Adapted from https://github.com/CraneStation/wasmtime/blob/5a1845b4caf7a5dba8eda1fef05213a532ed4259/crates/debug/src/transform/expression.rs#L59-L137 +fn translate_loc(isa: &dyn TargetIsa, loc: LabelValueLoc) -> Option<Expression> { + match loc { + LabelValueLoc::Reg(reg) => { + let machine_reg = isa.map_regalloc_reg_to_dwarf(reg).unwrap(); + let mut expr = Expression::new(); + expr.op_reg(gimli::Register(machine_reg)); + Some(expr) + } + LabelValueLoc::SPOffset(offset) => { + let mut expr = Expression::new(); + expr.op_breg(X86_64::RSP, offset); + Some(expr) + } + } +} |