1 use super::address_transform::AddressTransform;
2 use super::expression::{compile_expression, CompiledExpression, FunctionFrameInfo};
3 use super::range_info_builder::RangeInfoBuilder;
4 use super::refs::{PendingDebugInfoRefs, PendingUnitRefs};
5 use super::{DebugInputContext, Reader, TransformError};
6 use anyhow::{bail, Error};
7 use cranelift_codegen::isa::TargetIsa;
8 use gimli::{
9     write, AttributeValue, DebugLineOffset, DebugLineStr, DebugStr, DebugStrOffsets,
10     DebuggingInformationEntry, Unit,
11 };
12 
13 #[derive(Debug)]
14 pub(crate) enum FileAttributeContext<'a> {
15     Root(Option<DebugLineOffset>),
16     Children {
17         file_map: &'a [write::FileId],
18         file_index_base: u64,
19         frame_base: Option<&'a CompiledExpression>,
20     },
21 }
22 
23 fn is_exprloc_to_loclist_allowed(attr_name: gimli::constants::DwAt) -> bool {
24     match attr_name {
25         gimli::DW_AT_location
26         | gimli::DW_AT_string_length
27         | gimli::DW_AT_return_addr
28         | gimli::DW_AT_data_member_location
29         | gimli::DW_AT_frame_base
30         | gimli::DW_AT_segment
31         | gimli::DW_AT_static_link
32         | gimli::DW_AT_use_location
33         | gimli::DW_AT_vtable_elem_location => true,
34         _ => false,
35     }
36 }
37 
38 pub(crate) fn clone_die_attributes<'a, R>(
39     dwarf: &gimli::Dwarf<R>,
40     unit: &Unit<R, R::Offset>,
41     entry: &DebuggingInformationEntry<R>,
42     context: &DebugInputContext<R>,
43     addr_tr: &'a AddressTransform,
44     frame_info: Option<&FunctionFrameInfo>,
45     out_unit: &mut write::Unit,
46     current_scope_id: write::UnitEntryId,
47     subprogram_range_builder: Option<RangeInfoBuilder>,
48     scope_ranges: Option<&Vec<(u64, u64)>>,
49     cu_low_pc: u64,
50     out_strings: &mut write::StringTable,
51     pending_die_refs: &mut PendingUnitRefs,
52     pending_di_refs: &mut PendingDebugInfoRefs,
53     file_context: FileAttributeContext<'a>,
54     isa: &dyn TargetIsa,
55 ) -> Result<(), Error>
56 where
57     R: Reader,
58 {
59     let unit_encoding = unit.encoding();
60 
61     let range_info = if let Some(subprogram_range_builder) = subprogram_range_builder {
62         subprogram_range_builder
63     } else {
64         // FIXME for CU: currently address_transform operate on a single
65         // function range, and when CU spans multiple ranges the
66         // transformation may be incomplete.
67         RangeInfoBuilder::from(dwarf, unit, entry, context, cu_low_pc)?
68     };
69     range_info.build(addr_tr, out_unit, current_scope_id);
70 
71     let mut attrs = entry.attrs();
72     while let Some(attr) = attrs.next()? {
73         let attr_value = match attr.value() {
74             AttributeValue::Addr(_) | AttributeValue::DebugAddrIndex(_)
75                 if attr.name() == gimli::DW_AT_low_pc =>
76             {
77                 continue;
78             }
79             AttributeValue::Udata(_) if attr.name() == gimli::DW_AT_high_pc => {
80                 continue;
81             }
82             AttributeValue::RangeListsRef(_) if attr.name() == gimli::DW_AT_ranges => {
83                 continue;
84             }
85             AttributeValue::Exprloc(_) if attr.name() == gimli::DW_AT_frame_base => {
86                 continue;
87             }
88             AttributeValue::DebugAddrBase(_) | AttributeValue::DebugStrOffsetsBase(_) => {
89                 continue;
90             }
91 
92             AttributeValue::Addr(u) => {
93                 let addr = addr_tr.translate(u).unwrap_or(write::Address::Constant(0));
94                 write::AttributeValue::Address(addr)
95             }
96             AttributeValue::DebugAddrIndex(i) => {
97                 let u = context.debug_addr.get_address(4, unit.addr_base, i)?;
98                 let addr = addr_tr.translate(u).unwrap_or(write::Address::Constant(0));
99                 write::AttributeValue::Address(addr)
100             }
101             AttributeValue::Udata(u) => write::AttributeValue::Udata(u),
102             AttributeValue::Data1(d) => write::AttributeValue::Data1(d),
103             AttributeValue::Data2(d) => write::AttributeValue::Data2(d),
104             AttributeValue::Data4(d) => write::AttributeValue::Data4(d),
105             AttributeValue::Sdata(d) => write::AttributeValue::Sdata(d),
106             AttributeValue::Flag(f) => write::AttributeValue::Flag(f),
107             AttributeValue::DebugLineRef(line_program_offset) => {
108                 if let FileAttributeContext::Root(o) = file_context {
109                     if o != Some(line_program_offset) {
110                         return Err(TransformError("invalid debug_line offset").into());
111                     }
112                     write::AttributeValue::LineProgramRef
113                 } else {
114                     return Err(TransformError("unexpected debug_line index attribute").into());
115                 }
116             }
117             AttributeValue::FileIndex(i) => {
118                 if let FileAttributeContext::Children {
119                     file_map,
120                     file_index_base,
121                     ..
122                 } = file_context
123                 {
124                     write::AttributeValue::FileIndex(Some(file_map[(i - file_index_base) as usize]))
125                 } else {
126                     return Err(TransformError("unexpected file index attribute").into());
127                 }
128             }
129             AttributeValue::DebugStrRef(str_offset) => {
130                 let s = context.debug_str.get_str(str_offset)?.to_slice()?.to_vec();
131                 write::AttributeValue::StringRef(out_strings.add(s))
132             }
133             AttributeValue::DebugStrOffsetsIndex(i) => {
134                 let str_offset = context.debug_str_offsets.get_str_offset(
135                     gimli::Format::Dwarf32,
136                     unit.str_offsets_base,
137                     i,
138                 )?;
139                 let s = context.debug_str.get_str(str_offset)?.to_slice()?.to_vec();
140                 write::AttributeValue::StringRef(out_strings.add(s))
141             }
142             AttributeValue::RangeListsRef(r) => {
143                 let r = dwarf.ranges_offset_from_raw(unit, r);
144                 let range_info = RangeInfoBuilder::from_ranges_ref(unit, r, context, cu_low_pc)?;
145                 let range_list_id = range_info.build_ranges(addr_tr, &mut out_unit.ranges);
146                 write::AttributeValue::RangeListRef(range_list_id)
147             }
148             AttributeValue::LocationListsRef(r) => {
149                 let low_pc = 0;
150                 let mut locs = context.loclists.locations(
151                     r,
152                     unit_encoding,
153                     low_pc,
154                     &context.debug_addr,
155                     unit.addr_base,
156                 )?;
157                 let frame_base =
158                     if let FileAttributeContext::Children { frame_base, .. } = file_context {
159                         frame_base
160                     } else {
161                         None
162                     };
163 
164                 let mut result: Option<Vec<_>> = None;
165                 while let Some(loc) = locs.next()? {
166                     if let Some(expr) = compile_expression(&loc.data, unit_encoding, frame_base)? {
167                         let chunk = expr
168                             .build_with_locals(
169                                 &[(loc.range.begin, loc.range.end)],
170                                 addr_tr,
171                                 frame_info,
172                                 isa,
173                             )
174                             .filter(|i| {
175                                 // Ignore empty range
176                                 if let Ok((_, 0, _)) = i {
177                                     false
178                                 } else {
179                                     true
180                                 }
181                             })
182                             .map(|i| {
183                                 i.map(|(start, len, expr)| write::Location::StartLength {
184                                     begin: start,
185                                     length: len,
186                                     data: expr,
187                                 })
188                             })
189                             .collect::<Result<Vec<_>, _>>()?;
190                         match &mut result {
191                             Some(r) => r.extend(chunk),
192                             x @ None => *x = Some(chunk),
193                         }
194                     } else {
195                         // FIXME _expr contains invalid expression
196                         continue; // ignore entry
197                     }
198                 }
199                 if result.is_none() {
200                     continue; // no valid locations
201                 }
202                 let list_id = out_unit.locations.add(write::LocationList(result.unwrap()));
203                 write::AttributeValue::LocationListRef(list_id)
204             }
205             AttributeValue::Exprloc(ref expr) => {
206                 let frame_base =
207                     if let FileAttributeContext::Children { frame_base, .. } = file_context {
208                         frame_base
209                     } else {
210                         None
211                     };
212                 if let Some(expr) = compile_expression(expr, unit_encoding, frame_base)? {
213                     if expr.is_simple() {
214                         if let Some(expr) = expr.build() {
215                             write::AttributeValue::Exprloc(expr)
216                         } else {
217                             continue;
218                         }
219                     } else {
220                         // Conversion to loclist is required.
221                         if let Some(scope_ranges) = scope_ranges {
222                             let exprs = expr
223                                 .build_with_locals(scope_ranges, addr_tr, frame_info, isa)
224                                 .collect::<Result<Vec<_>, _>>()?;
225                             if exprs.is_empty() {
226                                 continue;
227                             }
228                             let found_single_expr = {
229                                 // Micro-optimization all expressions alike, use one exprloc.
230                                 let mut found_expr: Option<write::Expression> = None;
231                                 for (_, _, expr) in &exprs {
232                                     if let Some(ref prev_expr) = found_expr {
233                                         if expr == prev_expr {
234                                             continue; // the same expression
235                                         }
236                                         found_expr = None;
237                                         break;
238                                     }
239                                     found_expr = Some(expr.clone())
240                                 }
241                                 found_expr
242                             };
243                             if let Some(expr) = found_single_expr {
244                                 write::AttributeValue::Exprloc(expr)
245                             } else if is_exprloc_to_loclist_allowed(attr.name()) {
246                                 // Converting exprloc to loclist.
247                                 let mut locs = Vec::new();
248                                 for (begin, length, data) in exprs {
249                                     if length == 0 {
250                                         // Ignore empty range
251                                         continue;
252                                     }
253                                     locs.push(write::Location::StartLength {
254                                         begin,
255                                         length,
256                                         data,
257                                     });
258                                 }
259                                 let list_id = out_unit.locations.add(write::LocationList(locs));
260                                 write::AttributeValue::LocationListRef(list_id)
261                             } else {
262                                 continue;
263                             }
264                         } else {
265                             continue;
266                         }
267                     }
268                 } else {
269                     // FIXME _expr contains invalid expression
270                     continue; // ignore attribute
271                 }
272             }
273             AttributeValue::Encoding(e) => write::AttributeValue::Encoding(e),
274             AttributeValue::DecimalSign(e) => write::AttributeValue::DecimalSign(e),
275             AttributeValue::Endianity(e) => write::AttributeValue::Endianity(e),
276             AttributeValue::Accessibility(e) => write::AttributeValue::Accessibility(e),
277             AttributeValue::Visibility(e) => write::AttributeValue::Visibility(e),
278             AttributeValue::Virtuality(e) => write::AttributeValue::Virtuality(e),
279             AttributeValue::Language(e) => write::AttributeValue::Language(e),
280             AttributeValue::AddressClass(e) => write::AttributeValue::AddressClass(e),
281             AttributeValue::IdentifierCase(e) => write::AttributeValue::IdentifierCase(e),
282             AttributeValue::CallingConvention(e) => write::AttributeValue::CallingConvention(e),
283             AttributeValue::Inline(e) => write::AttributeValue::Inline(e),
284             AttributeValue::Ordering(e) => write::AttributeValue::Ordering(e),
285             AttributeValue::UnitRef(offset) => {
286                 pending_die_refs.insert(current_scope_id, attr.name(), offset);
287                 continue;
288             }
289             AttributeValue::DebugInfoRef(offset) => {
290                 pending_di_refs.insert(current_scope_id, attr.name(), offset);
291                 continue;
292             }
293             a => bail!("Unexpected attribute: {:?}", a),
294         };
295         let current_scope = out_unit.get_mut(current_scope_id);
296         current_scope.set(attr.name(), attr_value);
297     }
298     Ok(())
299 }
300 
301 pub(crate) fn clone_attr_string<R>(
302     attr_value: &AttributeValue<R>,
303     form: gimli::DwForm,
304     unit: &Unit<R, R::Offset>,
305     debug_str: &DebugStr<R>,
306     debug_str_offsets: &DebugStrOffsets<R>,
307     debug_line_str: &DebugLineStr<R>,
308     out_strings: &mut write::StringTable,
309 ) -> Result<write::LineString, Error>
310 where
311     R: Reader,
312 {
313     let content = match attr_value {
314         AttributeValue::DebugStrRef(str_offset) => {
315             debug_str.get_str(*str_offset)?.to_slice()?.to_vec()
316         }
317         AttributeValue::DebugStrOffsetsIndex(i) => {
318             let str_offset = debug_str_offsets.get_str_offset(
319                 gimli::Format::Dwarf32,
320                 unit.str_offsets_base,
321                 *i,
322             )?;
323             debug_str.get_str(str_offset)?.to_slice()?.to_vec()
324         }
325         AttributeValue::DebugLineStrRef(str_offset) => {
326             debug_line_str.get_str(*str_offset)?.to_slice()?.to_vec()
327         }
328         AttributeValue::String(b) => b.to_slice()?.to_vec(),
329         v => bail!("Unexpected attribute value: {:?}", v),
330     };
331     Ok(match form {
332         gimli::DW_FORM_strp => {
333             let id = out_strings.add(content);
334             write::LineString::StringRef(id)
335         }
336         gimli::DW_FORM_string => write::LineString::String(content),
337         _ => bail!("DW_FORM_line_strp or other not supported"),
338     })
339 }
340