vendor/addr2line/src/function.rs

   1 use alloc::boxed::Box;
   2 use alloc::vec::Vec;
   3 use core::cmp::Ordering;
   4 use core::iter;
   5
   6 use crate::lazy::LazyCell;
   7 use crate::maybe_small;
   8 use crate::{Error, RangeAttributes, ResDwarf};
   9
  10 pub(crate) struct Functions<R: gimli::Reader> {
  11     /// List of all `DW_TAG_subprogram` details in the unit.
  12     pub(crate) functions: Box<
  13         [(
  14             gimli::UnitOffset<R::Offset>,
  15             LazyCell<Result<Function<R>, Error>>,
  16         )],
  17     >,
  18     /// List of `DW_TAG_subprogram` address ranges in the unit.
  19     pub(crate) addresses: Box<[FunctionAddress]>,
  20 }
  21
  22 /// A single address range for a function.
  23 ///
  24 /// It is possible for a function to have multiple address ranges; this
  25 /// is handled by having multiple `FunctionAddress` entries with the same
  26 /// `function` field.
  27 pub(crate) struct FunctionAddress {
  28     range: gimli::Range,
  29     /// An index into `Functions::functions`.
  30     pub(crate) function: usize,
  31 }
  32
  33 pub(crate) struct Function<R: gimli::Reader> {
  34     pub(crate) dw_die_offset: gimli::UnitOffset<R::Offset>,
  35     pub(crate) name: Option<R>,
  36     /// List of all `DW_TAG_inlined_subroutine` details in this function.
  37     inlined_functions: Box<[InlinedFunction<R>]>,
  38     /// List of `DW_TAG_inlined_subroutine` address ranges in this function.
  39     inlined_addresses: Box<[InlinedFunctionAddress]>,
  40 }
  41
  42 pub(crate) struct InlinedFunctionAddress {
  43     range: gimli::Range,
  44     call_depth: usize,
  45     /// An index into `Function::inlined_functions`.
  46     function: usize,
  47 }
  48
  49 pub(crate) struct InlinedFunction<R: gimli::Reader> {
  50     pub(crate) dw_die_offset: gimli::UnitOffset<R::Offset>,
  51     pub(crate) name: Option<R>,
  52     pub(crate) call_file: u64,
  53     pub(crate) call_line: u32,
  54     pub(crate) call_column: u32,
  55 }
  56
  57 impl<R: gimli::Reader> Functions<R> {
  58     pub(crate) fn parse(unit: &gimli::Unit<R>, dwarf: &ResDwarf<R>) -> Result<Functions<R>, Error> {
  59         let mut functions = Vec::new();
  60         let mut addresses = Vec::new();
  61         let mut entries = unit.entries_raw(None)?;
  62         while !entries.is_empty() {
  63             let dw_die_offset = entries.next_offset();
  64             if let Some(abbrev) = entries.read_abbreviation()? {
  65                 if abbrev.tag() == gimli::DW_TAG_subprogram {
  66                     let mut ranges = RangeAttributes::default();
  67                     for spec in abbrev.attributes() {
  68                         match entries.read_attribute(*spec) {
  69                             Ok(ref attr) => {
  70                                 match attr.name() {
  71                                     gimli::DW_AT_low_pc => {
  72                                         if let gimli::AttributeValue::Addr(val) = attr.value() {
  73                                             ranges.low_pc = Some(val);
  74                                         }
  75                                     }
  76                                     gimli::DW_AT_high_pc => match attr.value() {
  77                                         gimli::AttributeValue::Addr(val) => {
  78                                             ranges.high_pc = Some(val)
  79                                         }
  80                                         gimli::AttributeValue::Udata(val) => {
  81                                             ranges.size = Some(val)
  82                                         }
  83                                         _ => {}
  84                                     },
  85                                     gimli::DW_AT_ranges => {
  86                                         ranges.ranges_offset = dwarf
  87                                             .sections
  88                                             .attr_ranges_offset(unit, attr.value())?;
  89                                     }
  90                                     _ => {}
  91                                 };
  92                             }
  93                             Err(e) => return Err(e),
  94                         }
  95                     }
  96
  97                     let function_index = functions.len();
  98                     if ranges.for_each_range(&dwarf.sections, unit, |range| {
  99                         addresses.push(FunctionAddress {
 100                             range,
 101                             function: function_index,
 102                         });
 103                     })? {
 104                         functions.push((dw_die_offset, LazyCell::new()));
 105                     }
 106                 } else {
 107                     entries.skip_attributes(abbrev.attributes())?;
 108                 }
 109             }
 110         }
 111
 112         // The binary search requires the addresses to be sorted.
 113         //
 114         // It also requires them to be non-overlapping.  In practice, overlapping
 115         // function ranges are unlikely, so we don't try to handle that yet.
 116         //
 117         // It's possible for multiple functions to have the same address range if the
 118         // compiler can detect and remove functions with identical code.  In that case
 119         // we'll nondeterministically return one of them.
 120         addresses.sort_by_key(|x| x.range.begin);
 121
 122         Ok(Functions {
 123             functions: functions.into_boxed_slice(),
 124             addresses: addresses.into_boxed_slice(),
 125         })
 126     }
 127
 128     pub(crate) fn find_address(&self, probe: u64) -> Option<usize> {
 129         self.addresses
 130             .binary_search_by(|address| {
 131                 if probe < address.range.begin {
 132                     Ordering::Greater
 133                 } else if probe >= address.range.end {
 134                     Ordering::Less
 135                 } else {
 136                     Ordering::Equal
 137                 }
 138             })
 139             .ok()
 140     }
 141
 142     pub(crate) fn parse_inlined_functions(
 143         &self,
 144         unit: &gimli::Unit<R>,
 145         dwarf: &ResDwarf<R>,
 146     ) -> Result<(), Error> {
 147         for function in &*self.functions {
 148             function
 149                 .1
 150                 .borrow_with(|| Function::parse(function.0, unit, dwarf))
 151                 .as_ref()
 152                 .map_err(Error::clone)?;
 153         }
 154         Ok(())
 155     }
 156 }
 157
 158 impl<R: gimli::Reader> Function<R> {
 159     pub(crate) fn parse(
 160         dw_die_offset: gimli::UnitOffset<R::Offset>,
 161         unit: &gimli::Unit<R>,
 162         dwarf: &ResDwarf<R>,
 163     ) -> Result<Self, Error> {
 164         let mut entries = unit.entries_raw(Some(dw_die_offset))?;
 165         let depth = entries.next_depth();
 166         let abbrev = entries.read_abbreviation()?.unwrap();
 167         debug_assert_eq!(abbrev.tag(), gimli::DW_TAG_subprogram);
 168
 169         let mut name = None;
 170         for spec in abbrev.attributes() {
 171             match entries.read_attribute(*spec) {
 172                 Ok(ref attr) => {
 173                     match attr.name() {
 174                         gimli::DW_AT_linkage_name | gimli::DW_AT_MIPS_linkage_name => {
 175                             if let Ok(val) = dwarf.sections.attr_string(unit, attr.value()) {
 176                                 name = Some(val);
 177                             }
 178                         }
 179                         gimli::DW_AT_name => {
 180                             if name.is_none() {
 181                                 name = dwarf.sections.attr_string(unit, attr.value()).ok();
 182                             }
 183                         }
 184                         gimli::DW_AT_abstract_origin | gimli::DW_AT_specification => {
 185                             if name.is_none() {
 186                                 name = name_attr(attr.value(), unit, dwarf, 16)?;
 187                             }
 188                         }
 189                         _ => {}
 190                     };
 191                 }
 192                 Err(e) => return Err(e),
 193             }
 194         }
 195
 196         let mut inlined_functions = Vec::new();
 197         let mut inlined_addresses = Vec::new();
 198         Function::parse_children(
 199             &mut entries,
 200             depth,
 201             unit,
 202             dwarf,
 203             &mut inlined_functions,
 204             &mut inlined_addresses,
 205             0,
 206         )?;
 207
 208         // Sort ranges in "breadth-first traversal order", i.e. first by call_depth
 209         // and then by range.begin. This allows finding the range containing an
 210         // address at a certain depth using binary search.
 211         // Note: Using DFS order, i.e. ordering by range.begin first and then by
 212         // call_depth, would not work! Consider the two examples
 213         // "[0..10 at depth 0], [0..2 at depth 1], [6..8 at depth 1]"  and
 214         // "[0..5 at depth 0], [0..2 at depth 1], [5..10 at depth 0], [6..8 at depth 1]".
 215         // In this example, if you want to look up address 7 at depth 0, and you
 216         // encounter [0..2 at depth 1], are you before or after the target range?
 217         // You don't know.
 218         inlined_addresses.sort_by(|r1, r2| {
 219             if r1.call_depth < r2.call_depth {
 220                 Ordering::Less
 221             } else if r1.call_depth > r2.call_depth {
 222                 Ordering::Greater
 223             } else if r1.range.begin < r2.range.begin {
 224                 Ordering::Less
 225             } else if r1.range.begin > r2.range.begin {
 226                 Ordering::Greater
 227             } else {
 228                 Ordering::Equal
 229             }
 230         });
 231
 232         Ok(Function {
 233             dw_die_offset,
 234             name,
 235             inlined_functions: inlined_functions.into_boxed_slice(),
 236             inlined_addresses: inlined_addresses.into_boxed_slice(),
 237         })
 238     }
 239
 240     fn parse_children(
 241         entries: &mut gimli::EntriesRaw<R>,
 242         depth: isize,
 243         unit: &gimli::Unit<R>,
 244         dwarf: &ResDwarf<R>,
 245         inlined_functions: &mut Vec<InlinedFunction<R>>,
 246         inlined_addresses: &mut Vec<InlinedFunctionAddress>,
 247         inlined_depth: usize,
 248     ) -> Result<(), Error> {
 249         loop {
 250             let dw_die_offset = entries.next_offset();
 251             let next_depth = entries.next_depth();
 252             if next_depth <= depth {
 253                 return Ok(());
 254             }
 255             if let Some(abbrev) = entries.read_abbreviation()? {
 256                 match abbrev.tag() {
 257                     gimli::DW_TAG_subprogram => {
 258                         Function::skip(entries, abbrev, next_depth)?;
 259                     }
 260                     gimli::DW_TAG_inlined_subroutine => {
 261                         InlinedFunction::parse(
 262                             dw_die_offset,
 263                             entries,
 264                             abbrev,
 265                             next_depth,
 266                             unit,
 267                             dwarf,
 268                             inlined_functions,
 269                             inlined_addresses,
 270                             inlined_depth,
 271                         )?;
 272                     }
 273                     _ => {
 274                         entries.skip_attributes(abbrev.attributes())?;
 275                     }
 276                 }
 277             }
 278         }
 279     }
 280
 281     fn skip(
 282         entries: &mut gimli::EntriesRaw<R>,
 283         abbrev: &gimli::Abbreviation,
 284         depth: isize,
 285     ) -> Result<(), Error> {
 286         // TODO: use DW_AT_sibling
 287         entries.skip_attributes(abbrev.attributes())?;
 288         while entries.next_depth() > depth {
 289             if let Some(abbrev) = entries.read_abbreviation()? {
 290                 entries.skip_attributes(abbrev.attributes())?;
 291             }
 292         }
 293         Ok(())
 294     }
 295
 296     /// Build the list of inlined functions that contain `probe`.
 297     pub(crate) fn find_inlined_functions(
 298         &self,
 299         probe: u64,
 300     ) -> iter::Rev<maybe_small::IntoIter<&InlinedFunction<R>>> {
 301         // `inlined_functions` is ordered from outside to inside.
 302         let mut inlined_functions = maybe_small::Vec::new();
 303         let mut inlined_addresses = &self.inlined_addresses[..];
 304         loop {
 305             let current_depth = inlined_functions.len();
 306             // Look up (probe, current_depth) in inline_ranges.
 307             // `inlined_addresses` is sorted in "breadth-first traversal order", i.e.
 308             // by `call_depth` first, and then by `range.begin`. See the comment at
 309             // the sort call for more information about why.
 310             let search = inlined_addresses.binary_search_by(|range| {
 311                 if range.call_depth > current_depth {
 312                     Ordering::Greater
 313                 } else if range.call_depth < current_depth {
 314                     Ordering::Less
 315                 } else if range.range.begin > probe {
 316                     Ordering::Greater
 317                 } else if range.range.end <= probe {
 318                     Ordering::Less
 319                 } else {
 320                     Ordering::Equal
 321                 }
 322             });
 323             if let Ok(index) = search {
 324                 let function_index = inlined_addresses[index].function;
 325                 inlined_functions.push(&self.inlined_functions[function_index]);
 326                 inlined_addresses = &inlined_addresses[index + 1..];
 327             } else {
 328                 break;
 329             }
 330         }
 331         inlined_functions.into_iter().rev()
 332     }
 333 }
 334
 335 impl<R: gimli::Reader> InlinedFunction<R> {
 336     fn parse(
 337         dw_die_offset: gimli::UnitOffset<R::Offset>,
 338         entries: &mut gimli::EntriesRaw<R>,
 339         abbrev: &gimli::Abbreviation,
 340         depth: isize,
 341         unit: &gimli::Unit<R>,
 342         dwarf: &ResDwarf<R>,
 343         inlined_functions: &mut Vec<InlinedFunction<R>>,
 344         inlined_addresses: &mut Vec<InlinedFunctionAddress>,
 345         inlined_depth: usize,
 346     ) -> Result<(), Error> {
 347         let mut ranges = RangeAttributes::default();
 348         let mut name = None;
 349         let mut call_file = 0;
 350         let mut call_line = 0;
 351         let mut call_column = 0;
 352         for spec in abbrev.attributes() {
 353             match entries.read_attribute(*spec) {
 354                 Ok(ref attr) => match attr.name() {
 355                     gimli::DW_AT_low_pc => {
 356                         if let gimli::AttributeValue::Addr(val) = attr.value() {
 357                             ranges.low_pc = Some(val);
 358                         }
 359                     }
 360                     gimli::DW_AT_high_pc => match attr.value() {
 361                         gimli::AttributeValue::Addr(val) => ranges.high_pc = Some(val),
 362                         gimli::AttributeValue::Udata(val) => ranges.size = Some(val),
 363                         _ => {}
 364                     },
 365                     gimli::DW_AT_ranges => {
 366                         ranges.ranges_offset =
 367                             dwarf.sections.attr_ranges_offset(unit, attr.value())?;
 368                     }
 369                     gimli::DW_AT_linkage_name | gimli::DW_AT_MIPS_linkage_name => {
 370                         if let Ok(val) = dwarf.sections.attr_string(unit, attr.value()) {
 371                             name = Some(val);
 372                         }
 373                     }
 374                     gimli::DW_AT_name => {
 375                         if name.is_none() {
 376                             name = dwarf.sections.attr_string(unit, attr.value()).ok();
 377                         }
 378                     }
 379                     gimli::DW_AT_abstract_origin | gimli::DW_AT_specification => {
 380                         if name.is_none() {
 381                             name = name_attr(attr.value(), unit, dwarf, 16)?;
 382                         }
 383                     }
 384                     gimli::DW_AT_call_file => {
 385                         if let gimli::AttributeValue::FileIndex(fi) = attr.value() {
 386                             call_file = fi;
 387                         }
 388                     }
 389                     gimli::DW_AT_call_line => {
 390                         call_line = attr.udata_value().unwrap_or(0) as u32;
 391                     }
 392                     gimli::DW_AT_call_column => {
 393                         call_column = attr.udata_value().unwrap_or(0) as u32;
 394                     }
 395                     _ => {}
 396                 },
 397                 Err(e) => return Err(e),
 398             }
 399         }
 400
 401         let function_index = inlined_functions.len();
 402         inlined_functions.push(InlinedFunction {
 403             dw_die_offset,
 404             name,
 405             call_file,
 406             call_line,
 407             call_column,
 408         });
 409
 410         ranges.for_each_range(&dwarf.sections, unit, |range| {
 411             inlined_addresses.push(InlinedFunctionAddress {
 412                 range,
 413                 call_depth: inlined_depth,
 414                 function: function_index,
 415             });
 416         })?;
 417
 418         Function::parse_children(
 419             entries,
 420             depth,
 421             unit,
 422             dwarf,
 423             inlined_functions,
 424             inlined_addresses,
 425             inlined_depth + 1,
 426         )
 427     }
 428 }
 429
 430 fn name_attr<R>(
 431     attr: gimli::AttributeValue<R>,
 432     unit: &gimli::Unit<R>,
 433     dwarf: &ResDwarf<R>,
 434     recursion_limit: usize,
 435 ) -> Result<Option<R>, Error>
 436 where
 437     R: gimli::Reader,
 438 {
 439     if recursion_limit == 0 {
 440         return Ok(None);
 441     }
 442
 443     match attr {
 444         gimli::AttributeValue::UnitRef(offset) => name_entry(unit, offset, dwarf, recursion_limit),
 445         gimli::AttributeValue::DebugInfoRef(dr) => {
 446             let res_unit = dwarf.find_unit(dr)?;
 447             name_entry(
 448                 &res_unit.dw_unit,
 449                 gimli::UnitOffset(dr.0 - res_unit.offset.0),
 450                 dwarf,
 451                 recursion_limit,
 452             )
 453         }
 454         gimli::AttributeValue::DebugInfoRefSup(dr) => {
 455             if let Some(sup_dwarf) = dwarf.sup.as_ref() {
 456                 let res_unit = sup_dwarf.find_unit(dr)?;
 457                 name_entry(
 458                     &res_unit.dw_unit,
 459                     gimli::UnitOffset(dr.0 - res_unit.offset.0),
 460                     sup_dwarf,
 461                     recursion_limit,
 462                 )
 463             } else {
 464                 Ok(None)
 465             }
 466         }
 467         _ => Ok(None),
 468     }
 469 }
 470
 471 fn name_entry<R>(
 472     unit: &gimli::Unit<R>,
 473     offset: gimli::UnitOffset<R::Offset>,
 474     dwarf: &ResDwarf<R>,
 475     recursion_limit: usize,
 476 ) -> Result<Option<R>, Error>
 477 where
 478     R: gimli::Reader,
 479 {
 480     let mut entries = unit.entries_raw(Some(offset))?;
 481     let abbrev = if let Some(abbrev) = entries.read_abbreviation()? {
 482         abbrev
 483     } else {
 484         return Err(gimli::Error::NoEntryAtGivenOffset);
 485     };
 486
 487     let mut name = None;
 488     let mut next = None;
 489     for spec in abbrev.attributes() {
 490         match entries.read_attribute(*spec) {
 491             Ok(ref attr) => match attr.name() {
 492                 gimli::DW_AT_linkage_name | gimli::DW_AT_MIPS_linkage_name => {
 493                     if let Ok(val) = dwarf.sections.attr_string(unit, attr.value()) {
 494                         return Ok(Some(val));
 495                     }
 496                 }
 497                 gimli::DW_AT_name => {
 498                     if let Ok(val) = dwarf.sections.attr_string(unit, attr.value()) {
 499                         name = Some(val);
 500                     }
 501                 }
 502                 gimli::DW_AT_abstract_origin | gimli::DW_AT_specification => {
 503                     next = Some(attr.value());
 504                 }
 505                 _ => {}
 506             },
 507             Err(e) => return Err(e),
 508         }
 509     }
 510
 511     if name.is_some() {
 512         return Ok(name);
 513     }
 514
 515     if let Some(next) = next {
 516         return name_attr(next, unit, dwarf, recursion_limit - 1);
 517     }
 518
 519     Ok(None)
 520 }