1 //! Handling of everything related to debuginfo.
10 use rustc_index::vec::IndexVec;
12 use cranelift_codegen::entity::EntityRef;
13 use cranelift_codegen::ir::{Endianness, LabelValueLoc, ValueLabel};
14 use cranelift_codegen::isa::TargetIsa;
15 use cranelift_codegen::ValueLocRange;
18 Address, AttributeValue, DwarfUnit, Expression, LineProgram, LineString, Location,
19 LocationList, Range, RangeList, UnitEntryId,
21 use gimli::{Encoding, Format, LineEncoding, RunTimeEndian, X86_64};
23 pub(crate) use emit::{DebugReloc, DebugRelocName};
24 pub(crate) use unwind::UnwindContext;
26 pub(crate) struct DebugContext<'tcx> {
29 endian: RunTimeEndian,
32 unit_range_list: RangeList,
34 types: FxHashMap<Ty<'tcx>, UnitEntryId>,
37 impl<'tcx> DebugContext<'tcx> {
38 pub(crate) fn new(tcx: TyCtxt<'tcx>, isa: &dyn TargetIsa) -> Self {
39 let encoding = Encoding {
40 format: Format::Dwarf32,
41 // FIXME this should be configurable
42 // macOS doesn't seem to support DWARF > 3
43 // 5 version is required for md5 file hash
44 version: if tcx.sess.target.is_like_osx {
47 // FIXME change to version 5 once the gdb and lldb shipping with the latest debian
51 address_size: isa.frontend_config().pointer_bytes(),
54 let endian = match isa.endianness() {
55 Endianness::Little => RunTimeEndian::Little,
56 Endianness::Big => RunTimeEndian::Big,
59 let mut dwarf = DwarfUnit::new(encoding);
61 let producer = format!(
62 "cg_clif (rustc {}, cranelift {})",
63 rustc_interface::util::version_str().unwrap_or("unknown version"),
64 cranelift_codegen::VERSION,
70 .to_string_lossy(FileNameDisplayPreference::Remapped)
72 let (name, file_info) = match tcx.sess.local_crate_source_file.clone() {
74 let name = path.to_string_lossy().into_owned();
77 None => (tcx.crate_name(LOCAL_CRATE).to_string(), None),
80 let mut line_program = LineProgram::new(
82 LineEncoding::default(),
83 LineString::new(comp_dir.as_bytes(), encoding, &mut dwarf.line_strings),
84 LineString::new(name.as_bytes(), encoding, &mut dwarf.line_strings),
87 line_program.file_has_md5 = file_info.is_some();
89 dwarf.unit.line_program = line_program;
92 let name = dwarf.strings.add(name);
93 let comp_dir = dwarf.strings.add(comp_dir);
95 let root = dwarf.unit.root();
96 let root = dwarf.unit.get_mut(root);
97 root.set(gimli::DW_AT_producer, AttributeValue::StringRef(dwarf.strings.add(producer)));
98 root.set(gimli::DW_AT_language, AttributeValue::Language(gimli::DW_LANG_Rust));
99 root.set(gimli::DW_AT_name, AttributeValue::StringRef(name));
100 root.set(gimli::DW_AT_comp_dir, AttributeValue::StringRef(comp_dir));
101 root.set(gimli::DW_AT_low_pc, AttributeValue::Address(Address::Constant(0)));
110 unit_range_list: RangeList(Vec::new()),
112 types: FxHashMap::default(),
116 fn dwarf_ty(&mut self, ty: Ty<'tcx>) -> UnitEntryId {
117 if let Some(type_id) = self.types.get(&ty) {
121 let new_entry = |dwarf: &mut DwarfUnit, tag| dwarf.unit.add(dwarf.unit.root(), tag);
123 let primitive = |dwarf: &mut DwarfUnit, ate| {
124 let type_id = new_entry(dwarf, gimli::DW_TAG_base_type);
125 let type_entry = dwarf.unit.get_mut(type_id);
126 type_entry.set(gimli::DW_AT_encoding, AttributeValue::Encoding(ate));
130 let name = format!("{}", ty);
131 let layout = self.tcx.layout_of(ParamEnv::reveal_all().and(ty)).unwrap();
133 let type_id = match ty.kind() {
134 ty::Bool => primitive(&mut self.dwarf, gimli::DW_ATE_boolean),
135 ty::Char => primitive(&mut self.dwarf, gimli::DW_ATE_UTF),
136 ty::Uint(_) => primitive(&mut self.dwarf, gimli::DW_ATE_unsigned),
137 ty::Int(_) => primitive(&mut self.dwarf, gimli::DW_ATE_signed),
138 ty::Float(_) => primitive(&mut self.dwarf, gimli::DW_ATE_float),
139 ty::Ref(_, pointee_ty, _mutbl)
140 | ty::RawPtr(ty::TypeAndMut { ty: pointee_ty, mutbl: _mutbl }) => {
141 let type_id = new_entry(&mut self.dwarf, gimli::DW_TAG_pointer_type);
143 // Ensure that type is inserted before recursing to avoid duplicates
144 self.types.insert(ty, type_id);
146 let pointee = self.dwarf_ty(*pointee_ty);
148 let type_entry = self.dwarf.unit.get_mut(type_id);
150 //type_entry.set(gimli::DW_AT_mutable, AttributeValue::Flag(mutbl == rustc_hir::Mutability::Mut));
151 type_entry.set(gimli::DW_AT_type, AttributeValue::UnitRef(pointee));
155 ty::Adt(adt_def, _substs) if adt_def.is_struct() && !layout.is_unsized() => {
156 let type_id = new_entry(&mut self.dwarf, gimli::DW_TAG_structure_type);
158 // Ensure that type is inserted before recursing to avoid duplicates
159 self.types.insert(ty, type_id);
161 let variant = adt_def.non_enum_variant();
163 for (field_idx, field_def) in variant.fields.iter().enumerate() {
164 let field_offset = layout.fields.offset(field_idx);
165 let field_layout = layout.field(
166 &layout::LayoutCx { tcx: self.tcx, param_env: ParamEnv::reveal_all() },
170 let field_type = self.dwarf_ty(field_layout.ty);
172 let field_id = self.dwarf.unit.add(type_id, gimli::DW_TAG_member);
173 let field_entry = self.dwarf.unit.get_mut(field_id);
177 AttributeValue::String(field_def.name.as_str().to_string().into_bytes()),
180 gimli::DW_AT_data_member_location,
181 AttributeValue::Udata(field_offset.bytes()),
183 field_entry.set(gimli::DW_AT_type, AttributeValue::UnitRef(field_type));
188 _ => new_entry(&mut self.dwarf, gimli::DW_TAG_structure_type),
191 let type_entry = self.dwarf.unit.get_mut(type_id);
193 type_entry.set(gimli::DW_AT_name, AttributeValue::String(name.into_bytes()));
194 type_entry.set(gimli::DW_AT_byte_size, AttributeValue::Udata(layout.size.bytes()));
196 self.types.insert(ty, type_id);
201 fn define_local(&mut self, scope: UnitEntryId, name: String, ty: Ty<'tcx>) -> UnitEntryId {
202 let dw_ty = self.dwarf_ty(ty);
204 let var_id = self.dwarf.unit.add(scope, gimli::DW_TAG_variable);
205 let var_entry = self.dwarf.unit.get_mut(var_id);
207 var_entry.set(gimli::DW_AT_name, AttributeValue::String(name.into_bytes()));
208 var_entry.set(gimli::DW_AT_type, AttributeValue::UnitRef(dw_ty));
213 pub(crate) fn define_function(
215 instance: Instance<'tcx>,
220 source_info_set: &indexmap::IndexSet<SourceInfo>,
221 local_map: IndexVec<mir::Local, CPlace<'tcx>>,
223 let symbol = func_id.as_u32() as usize;
224 let mir = self.tcx.instance_mir(instance.def);
226 // FIXME: add to appropriate scope instead of root
227 let scope = self.dwarf.unit.root();
229 let entry_id = self.dwarf.unit.add(scope, gimli::DW_TAG_subprogram);
230 let entry = self.dwarf.unit.get_mut(entry_id);
231 let name_id = self.dwarf.strings.add(name);
232 // Gdb requires DW_AT_name. Otherwise the DW_TAG_subprogram is skipped.
233 entry.set(gimli::DW_AT_name, AttributeValue::StringRef(name_id));
234 entry.set(gimli::DW_AT_linkage_name, AttributeValue::StringRef(name_id));
236 let end = self.create_debug_lines(symbol, entry_id, context, mir.span, source_info_set);
238 self.unit_range_list.0.push(Range::StartLength {
239 begin: Address::Symbol { symbol, addend: 0 },
240 length: u64::from(end),
243 let func_entry = self.dwarf.unit.get_mut(entry_id);
244 // Gdb requires both DW_AT_low_pc and DW_AT_high_pc. Otherwise the DW_TAG_subprogram is skipped.
247 AttributeValue::Address(Address::Symbol { symbol, addend: 0 }),
249 // Using Udata for DW_AT_high_pc requires at least DWARF4
250 func_entry.set(gimli::DW_AT_high_pc, AttributeValue::Udata(u64::from(end)));
252 // FIXME make it more reliable and implement scopes before re-enabling this.
254 let value_labels_ranges = std::collections::HashMap::new(); // FIXME
256 for (local, _local_decl) in mir.local_decls.iter_enumerated() {
257 let ty = self.tcx.subst_and_normalize_erasing_regions(
259 ty::ParamEnv::reveal_all(),
260 mir.local_decls[local].ty,
262 let var_id = self.define_local(entry_id, format!("{:?}", local), ty);
264 let location = place_location(
269 &value_labels_ranges,
270 Place { local, projection: ty::List::empty() },
273 let var_entry = self.dwarf.unit.get_mut(var_id);
274 var_entry.set(gimli::DW_AT_location, location);
278 // FIXME create locals for all entries in mir.var_debug_info
282 fn place_location<'tcx>(
283 debug_context: &mut DebugContext<'tcx>,
286 local_map: &IndexVec<mir::Local, CPlace<'tcx>>,
287 #[allow(rustc::default_hash_types)] value_labels_ranges: &std::collections::HashMap<
292 ) -> AttributeValue {
293 assert!(place.projection.is_empty()); // FIXME implement them
295 match local_map[place.local].inner() {
296 CPlaceInner::Var(_local, var) => {
297 let value_label = cranelift_codegen::ir::ValueLabel::new(var.index());
298 if let Some(value_loc_ranges) = value_labels_ranges.get(&value_label) {
299 let loc_list = LocationList(
302 .map(|value_loc_range| Location::StartEnd {
303 begin: Address::Symbol {
305 addend: i64::from(value_loc_range.start),
307 end: Address::Symbol { symbol, addend: i64::from(value_loc_range.end) },
308 data: translate_loc(isa, value_loc_range.loc).unwrap(),
312 let loc_list_id = debug_context.dwarf.unit.locations.add(loc_list);
314 AttributeValue::LocationListRef(loc_list_id)
316 // FIXME set value labels for unused locals
318 AttributeValue::Exprloc(Expression::new())
321 CPlaceInner::VarPair(_, _, _) => {
322 // FIXME implement this
324 AttributeValue::Exprloc(Expression::new())
326 CPlaceInner::VarLane(_, _, _) => {
327 // FIXME implement this
329 AttributeValue::Exprloc(Expression::new())
331 CPlaceInner::Addr(_, _) => {
332 // FIXME implement this (used by arguments and returns)
334 AttributeValue::Exprloc(Expression::new())
336 // For PointerBase::Stack:
337 //AttributeValue::Exprloc(translate_loc(ValueLoc::Stack(*stack_slot)).unwrap())
342 // Adapted from https://github.com/CraneStation/wasmtime/blob/5a1845b4caf7a5dba8eda1fef05213a532ed4259/crates/debug/src/transform/expression.rs#L59-L137
343 fn translate_loc(isa: &dyn TargetIsa, loc: LabelValueLoc) -> Option<Expression> {
345 LabelValueLoc::Reg(reg) => {
346 let machine_reg = isa.map_regalloc_reg_to_dwarf(reg).unwrap();
347 let mut expr = Expression::new();
348 expr.op_reg(gimli::Register(machine_reg));
351 LabelValueLoc::SPOffset(offset) => {
352 let mut expr = Expression::new();
353 expr.op_breg(X86_64::RSP, offset);