gimli/read/
loclists.rs

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1use crate::common::{
2    DebugAddrBase, DebugAddrIndex, DebugLocListsBase, DebugLocListsIndex, DwarfFileType, Encoding,
3    LocationListsOffset, SectionId,
4};
5use crate::constants;
6use crate::endianity::Endianity;
7use crate::read::{
8    lists::ListsHeader, DebugAddr, EndianSlice, Error, Expression, Range, RawRange, Reader,
9    ReaderAddress, ReaderOffset, ReaderOffsetId, Result, Section,
10};
11
12/// The raw contents of the `.debug_loc` section.
13#[derive(Debug, Default, Clone, Copy)]
14pub struct DebugLoc<R> {
15    pub(crate) section: R,
16}
17
18impl<'input, Endian> DebugLoc<EndianSlice<'input, Endian>>
19where
20    Endian: Endianity,
21{
22    /// Construct a new `DebugLoc` instance from the data in the `.debug_loc`
23    /// section.
24    ///
25    /// It is the caller's responsibility to read the `.debug_loc` section and
26    /// present it as a `&[u8]` slice. That means using some ELF loader on
27    /// Linux, a Mach-O loader on macOS, etc.
28    ///
29    /// ```
30    /// use gimli::{DebugLoc, LittleEndian};
31    ///
32    /// # let buf = [0x00, 0x01, 0x02, 0x03];
33    /// # let read_debug_loc_section_somehow = || &buf;
34    /// let debug_loc = DebugLoc::new(read_debug_loc_section_somehow(), LittleEndian);
35    /// ```
36    pub fn new(section: &'input [u8], endian: Endian) -> Self {
37        Self::from(EndianSlice::new(section, endian))
38    }
39}
40
41impl<T> DebugLoc<T> {
42    /// Create a `DebugLoc` section that references the data in `self`.
43    ///
44    /// This is useful when `R` implements `Reader` but `T` does not.
45    ///
46    /// Used by `DwarfSections::borrow`.
47    pub(crate) fn borrow<'a, F, R>(&'a self, mut borrow: F) -> DebugLoc<R>
48    where
49        F: FnMut(&'a T) -> R,
50    {
51        borrow(&self.section).into()
52    }
53}
54
55impl<R> Section<R> for DebugLoc<R> {
56    fn id() -> SectionId {
57        SectionId::DebugLoc
58    }
59
60    fn reader(&self) -> &R {
61        &self.section
62    }
63}
64
65impl<R> From<R> for DebugLoc<R> {
66    fn from(section: R) -> Self {
67        DebugLoc { section }
68    }
69}
70
71/// The `DebugLocLists` struct represents the DWARF data
72/// found in the `.debug_loclists` section.
73#[derive(Debug, Default, Clone, Copy)]
74pub struct DebugLocLists<R> {
75    section: R,
76}
77
78impl<'input, Endian> DebugLocLists<EndianSlice<'input, Endian>>
79where
80    Endian: Endianity,
81{
82    /// Construct a new `DebugLocLists` instance from the data in the `.debug_loclists`
83    /// section.
84    ///
85    /// It is the caller's responsibility to read the `.debug_loclists` section and
86    /// present it as a `&[u8]` slice. That means using some ELF loader on
87    /// Linux, a Mach-O loader on macOS, etc.
88    ///
89    /// ```
90    /// use gimli::{DebugLocLists, LittleEndian};
91    ///
92    /// # let buf = [0x00, 0x01, 0x02, 0x03];
93    /// # let read_debug_loclists_section_somehow = || &buf;
94    /// let debug_loclists = DebugLocLists::new(read_debug_loclists_section_somehow(), LittleEndian);
95    /// ```
96    pub fn new(section: &'input [u8], endian: Endian) -> Self {
97        Self::from(EndianSlice::new(section, endian))
98    }
99}
100
101impl<T> DebugLocLists<T> {
102    /// Create a `DebugLocLists` section that references the data in `self`.
103    ///
104    /// This is useful when `R` implements `Reader` but `T` does not.
105    ///
106    /// Used by `DwarfSections::borrow`.
107    pub(crate) fn borrow<'a, F, R>(&'a self, mut borrow: F) -> DebugLocLists<R>
108    where
109        F: FnMut(&'a T) -> R,
110    {
111        borrow(&self.section).into()
112    }
113}
114
115impl<R> Section<R> for DebugLocLists<R> {
116    fn id() -> SectionId {
117        SectionId::DebugLocLists
118    }
119
120    fn reader(&self) -> &R {
121        &self.section
122    }
123}
124
125impl<R> From<R> for DebugLocLists<R> {
126    fn from(section: R) -> Self {
127        DebugLocLists { section }
128    }
129}
130
131pub(crate) type LocListsHeader = ListsHeader;
132
133impl<Offset> DebugLocListsBase<Offset>
134where
135    Offset: ReaderOffset,
136{
137    /// Returns a `DebugLocListsBase` with the default value of DW_AT_loclists_base
138    /// for the given `Encoding` and `DwarfFileType`.
139    pub fn default_for_encoding_and_file(
140        encoding: Encoding,
141        file_type: DwarfFileType,
142    ) -> DebugLocListsBase<Offset> {
143        if encoding.version >= 5 && file_type == DwarfFileType::Dwo {
144            // In .dwo files, the compiler omits the DW_AT_loclists_base attribute (because there is
145            // only a single unit in the file) but we must skip past the header, which the attribute
146            // would normally do for us.
147            DebugLocListsBase(Offset::from_u8(LocListsHeader::size_for_encoding(encoding)))
148        } else {
149            DebugLocListsBase(Offset::from_u8(0))
150        }
151    }
152}
153
154/// The DWARF data found in `.debug_loc` and `.debug_loclists` sections.
155#[derive(Debug, Default, Clone, Copy)]
156pub struct LocationLists<R> {
157    debug_loc: DebugLoc<R>,
158    debug_loclists: DebugLocLists<R>,
159}
160
161impl<R> LocationLists<R> {
162    /// Construct a new `LocationLists` instance from the data in the `.debug_loc` and
163    /// `.debug_loclists` sections.
164    pub fn new(debug_loc: DebugLoc<R>, debug_loclists: DebugLocLists<R>) -> LocationLists<R> {
165        LocationLists {
166            debug_loc,
167            debug_loclists,
168        }
169    }
170}
171
172impl<T> LocationLists<T> {
173    /// Create a `LocationLists` that references the data in `self`.
174    ///
175    /// This is useful when `R` implements `Reader` but `T` does not.
176    ///
177    /// Used by `Dwarf::borrow`.
178    pub fn borrow<'a, F, R>(&'a self, mut borrow: F) -> LocationLists<R>
179    where
180        F: FnMut(&'a T) -> R,
181    {
182        LocationLists {
183            debug_loc: borrow(&self.debug_loc.section).into(),
184            debug_loclists: borrow(&self.debug_loclists.section).into(),
185        }
186    }
187}
188
189impl<R: Reader> LocationLists<R> {
190    /// Iterate over the `LocationListEntry`s starting at the given offset.
191    ///
192    /// The `unit_encoding` must match the compilation unit that the
193    /// offset was contained in.
194    ///
195    /// The `base_address` should be obtained from the `DW_AT_low_pc` attribute in the
196    /// `DW_TAG_compile_unit` entry for the compilation unit that contains this location
197    /// list.
198    ///
199    /// Can be [used with
200    /// `FallibleIterator`](./index.html#using-with-fallibleiterator).
201    pub fn locations(
202        &self,
203        offset: LocationListsOffset<R::Offset>,
204        unit_encoding: Encoding,
205        base_address: u64,
206        debug_addr: &DebugAddr<R>,
207        debug_addr_base: DebugAddrBase<R::Offset>,
208    ) -> Result<LocListIter<R>> {
209        Ok(LocListIter::new(
210            self.raw_locations(offset, unit_encoding)?,
211            base_address,
212            debug_addr.clone(),
213            debug_addr_base,
214        ))
215    }
216
217    /// Similar to `locations`, but with special handling for .dwo files.
218    /// This should only been used when this `LocationLists` was loaded from a
219    /// .dwo file.
220    pub fn locations_dwo(
221        &self,
222        offset: LocationListsOffset<R::Offset>,
223        unit_encoding: Encoding,
224        base_address: u64,
225        debug_addr: &DebugAddr<R>,
226        debug_addr_base: DebugAddrBase<R::Offset>,
227    ) -> Result<LocListIter<R>> {
228        Ok(LocListIter::new(
229            self.raw_locations_dwo(offset, unit_encoding)?,
230            base_address,
231            debug_addr.clone(),
232            debug_addr_base,
233        ))
234    }
235
236    /// Iterate over the raw `LocationListEntry`s starting at the given offset.
237    ///
238    /// The `unit_encoding` must match the compilation unit that the
239    /// offset was contained in.
240    ///
241    /// This iterator does not perform any processing of the location entries,
242    /// such as handling base addresses.
243    ///
244    /// Can be [used with
245    /// `FallibleIterator`](./index.html#using-with-fallibleiterator).
246    pub fn raw_locations(
247        &self,
248        offset: LocationListsOffset<R::Offset>,
249        unit_encoding: Encoding,
250    ) -> Result<RawLocListIter<R>> {
251        let (mut input, format) = if unit_encoding.version <= 4 {
252            (self.debug_loc.section.clone(), LocListsFormat::Bare)
253        } else {
254            (self.debug_loclists.section.clone(), LocListsFormat::Lle)
255        };
256        input.skip(offset.0)?;
257        Ok(RawLocListIter::new(input, unit_encoding, format))
258    }
259
260    /// Similar to `raw_locations`, but with special handling for .dwo files.
261    /// This should only been used when this `LocationLists` was loaded from a
262    /// .dwo file.
263    pub fn raw_locations_dwo(
264        &self,
265        offset: LocationListsOffset<R::Offset>,
266        unit_encoding: Encoding,
267    ) -> Result<RawLocListIter<R>> {
268        let mut input = if unit_encoding.version <= 4 {
269            // In the GNU split dwarf extension the locations are present in the
270            // .debug_loc section but are encoded with the DW_LLE values used
271            // for the DWARF 5 .debug_loclists section.
272            self.debug_loc.section.clone()
273        } else {
274            self.debug_loclists.section.clone()
275        };
276        input.skip(offset.0)?;
277        Ok(RawLocListIter::new(
278            input,
279            unit_encoding,
280            LocListsFormat::Lle,
281        ))
282    }
283
284    /// Returns the `.debug_loclists` offset at the given `base` and `index`.
285    ///
286    /// The `base` must be the `DW_AT_loclists_base` value from the compilation unit DIE.
287    /// This is an offset that points to the first entry following the header.
288    ///
289    /// The `index` is the value of a `DW_FORM_loclistx` attribute.
290    pub fn get_offset(
291        &self,
292        unit_encoding: Encoding,
293        base: DebugLocListsBase<R::Offset>,
294        index: DebugLocListsIndex<R::Offset>,
295    ) -> Result<LocationListsOffset<R::Offset>> {
296        let format = unit_encoding.format;
297        let input = &mut self.debug_loclists.section.clone();
298        input.skip(base.0)?;
299        input.skip(R::Offset::from_u64(
300            index.0.into_u64() * u64::from(format.word_size()),
301        )?)?;
302        input
303            .read_offset(format)
304            .map(|x| LocationListsOffset(base.0 + x))
305    }
306
307    /// Call `Reader::lookup_offset_id` for each section, and return the first match.
308    pub fn lookup_offset_id(&self, id: ReaderOffsetId) -> Option<(SectionId, R::Offset)> {
309        self.debug_loc
310            .lookup_offset_id(id)
311            .or_else(|| self.debug_loclists.lookup_offset_id(id))
312    }
313}
314
315#[derive(Debug, Clone, Copy, PartialEq, Eq)]
316enum LocListsFormat {
317    /// The bare location list format used before DWARF 5.
318    Bare,
319    /// The DW_LLE encoded range list format used in DWARF 5 and the non-standard GNU
320    /// split dwarf extension.
321    Lle,
322}
323
324/// A raw iterator over a location list.
325///
326/// This iterator does not perform any processing of the location entries,
327/// such as handling base addresses.
328#[derive(Debug)]
329pub struct RawLocListIter<R: Reader> {
330    input: R,
331    encoding: Encoding,
332    format: LocListsFormat,
333}
334
335/// A raw entry in .debug_loclists.
336#[derive(Clone, Debug)]
337pub enum RawLocListEntry<R: Reader> {
338    /// A location from DWARF version <= 4.
339    AddressOrOffsetPair {
340        /// Start of range. May be an address or an offset.
341        begin: u64,
342        /// End of range. May be an address or an offset.
343        end: u64,
344        /// expression
345        data: Expression<R>,
346    },
347    /// DW_LLE_base_address
348    BaseAddress {
349        /// base address
350        addr: u64,
351    },
352    /// DW_LLE_base_addressx
353    BaseAddressx {
354        /// base address
355        addr: DebugAddrIndex<R::Offset>,
356    },
357    /// DW_LLE_startx_endx
358    StartxEndx {
359        /// start of range
360        begin: DebugAddrIndex<R::Offset>,
361        /// end of range
362        end: DebugAddrIndex<R::Offset>,
363        /// expression
364        data: Expression<R>,
365    },
366    /// DW_LLE_startx_length
367    StartxLength {
368        /// start of range
369        begin: DebugAddrIndex<R::Offset>,
370        /// length of range
371        length: u64,
372        /// expression
373        data: Expression<R>,
374    },
375    /// DW_LLE_offset_pair
376    OffsetPair {
377        /// start of range
378        begin: u64,
379        /// end of range
380        end: u64,
381        /// expression
382        data: Expression<R>,
383    },
384    /// DW_LLE_default_location
385    DefaultLocation {
386        /// expression
387        data: Expression<R>,
388    },
389    /// DW_LLE_start_end
390    StartEnd {
391        /// start of range
392        begin: u64,
393        /// end of range
394        end: u64,
395        /// expression
396        data: Expression<R>,
397    },
398    /// DW_LLE_start_length
399    StartLength {
400        /// start of range
401        begin: u64,
402        /// length of range
403        length: u64,
404        /// expression
405        data: Expression<R>,
406    },
407}
408
409fn parse_data<R: Reader>(input: &mut R, encoding: Encoding) -> Result<Expression<R>> {
410    if encoding.version >= 5 {
411        let len = R::Offset::from_u64(input.read_uleb128()?)?;
412        Ok(Expression(input.split(len)?))
413    } else {
414        // In the GNU split-dwarf extension this is a fixed 2 byte value.
415        let len = R::Offset::from_u16(input.read_u16()?);
416        Ok(Expression(input.split(len)?))
417    }
418}
419
420impl<R: Reader> RawLocListEntry<R> {
421    /// Parse a location list entry from `.debug_loclists`
422    fn parse(input: &mut R, encoding: Encoding, format: LocListsFormat) -> Result<Option<Self>> {
423        Ok(match format {
424            LocListsFormat::Bare => {
425                let range = RawRange::parse(input, encoding.address_size)?;
426                if range.is_end() {
427                    None
428                } else if range.is_base_address(encoding.address_size) {
429                    Some(RawLocListEntry::BaseAddress { addr: range.end })
430                } else {
431                    let len = R::Offset::from_u16(input.read_u16()?);
432                    let data = Expression(input.split(len)?);
433                    Some(RawLocListEntry::AddressOrOffsetPair {
434                        begin: range.begin,
435                        end: range.end,
436                        data,
437                    })
438                }
439            }
440            LocListsFormat::Lle => match constants::DwLle(input.read_u8()?) {
441                constants::DW_LLE_end_of_list => None,
442                constants::DW_LLE_base_addressx => Some(RawLocListEntry::BaseAddressx {
443                    addr: DebugAddrIndex(input.read_uleb128().and_then(R::Offset::from_u64)?),
444                }),
445                constants::DW_LLE_startx_endx => Some(RawLocListEntry::StartxEndx {
446                    begin: DebugAddrIndex(input.read_uleb128().and_then(R::Offset::from_u64)?),
447                    end: DebugAddrIndex(input.read_uleb128().and_then(R::Offset::from_u64)?),
448                    data: parse_data(input, encoding)?,
449                }),
450                constants::DW_LLE_startx_length => Some(RawLocListEntry::StartxLength {
451                    begin: DebugAddrIndex(input.read_uleb128().and_then(R::Offset::from_u64)?),
452                    length: if encoding.version >= 5 {
453                        input.read_uleb128()?
454                    } else {
455                        // In the GNU split-dwarf extension this is a fixed 4 byte value.
456                        input.read_u32()? as u64
457                    },
458                    data: parse_data(input, encoding)?,
459                }),
460                constants::DW_LLE_offset_pair => Some(RawLocListEntry::OffsetPair {
461                    begin: input.read_uleb128()?,
462                    end: input.read_uleb128()?,
463                    data: parse_data(input, encoding)?,
464                }),
465                constants::DW_LLE_default_location => Some(RawLocListEntry::DefaultLocation {
466                    data: parse_data(input, encoding)?,
467                }),
468                constants::DW_LLE_base_address => Some(RawLocListEntry::BaseAddress {
469                    addr: input.read_address(encoding.address_size)?,
470                }),
471                constants::DW_LLE_start_end => Some(RawLocListEntry::StartEnd {
472                    begin: input.read_address(encoding.address_size)?,
473                    end: input.read_address(encoding.address_size)?,
474                    data: parse_data(input, encoding)?,
475                }),
476                constants::DW_LLE_start_length => Some(RawLocListEntry::StartLength {
477                    begin: input.read_address(encoding.address_size)?,
478                    length: input.read_uleb128()?,
479                    data: parse_data(input, encoding)?,
480                }),
481                entry => {
482                    return Err(Error::UnknownLocListsEntry(entry));
483                }
484            },
485        })
486    }
487}
488
489impl<R: Reader> RawLocListIter<R> {
490    /// Construct a `RawLocListIter`.
491    fn new(input: R, encoding: Encoding, format: LocListsFormat) -> RawLocListIter<R> {
492        RawLocListIter {
493            input,
494            encoding,
495            format,
496        }
497    }
498
499    /// Advance the iterator to the next location.
500    pub fn next(&mut self) -> Result<Option<RawLocListEntry<R>>> {
501        if self.input.is_empty() {
502            return Ok(None);
503        }
504
505        match RawLocListEntry::parse(&mut self.input, self.encoding, self.format) {
506            Ok(entry) => {
507                if entry.is_none() {
508                    self.input.empty();
509                }
510                Ok(entry)
511            }
512            Err(e) => {
513                self.input.empty();
514                Err(e)
515            }
516        }
517    }
518}
519
520#[cfg(feature = "fallible-iterator")]
521impl<R: Reader> fallible_iterator::FallibleIterator for RawLocListIter<R> {
522    type Item = RawLocListEntry<R>;
523    type Error = Error;
524
525    fn next(&mut self) -> ::core::result::Result<Option<Self::Item>, Self::Error> {
526        RawLocListIter::next(self)
527    }
528}
529
530/// An iterator over a location list.
531///
532/// This iterator internally handles processing of base address selection entries
533/// and list end entries.  Thus, it only returns location entries that are valid
534/// and already adjusted for the base address.
535#[derive(Debug)]
536pub struct LocListIter<R: Reader> {
537    raw: RawLocListIter<R>,
538    base_address: u64,
539    debug_addr: DebugAddr<R>,
540    debug_addr_base: DebugAddrBase<R::Offset>,
541}
542
543impl<R: Reader> LocListIter<R> {
544    /// Construct a `LocListIter`.
545    fn new(
546        raw: RawLocListIter<R>,
547        base_address: u64,
548        debug_addr: DebugAddr<R>,
549        debug_addr_base: DebugAddrBase<R::Offset>,
550    ) -> LocListIter<R> {
551        LocListIter {
552            raw,
553            base_address,
554            debug_addr,
555            debug_addr_base,
556        }
557    }
558
559    #[inline]
560    fn get_address(&self, index: DebugAddrIndex<R::Offset>) -> Result<u64> {
561        self.debug_addr
562            .get_address(self.raw.encoding.address_size, self.debug_addr_base, index)
563    }
564
565    /// Advance the iterator to the next location.
566    pub fn next(&mut self) -> Result<Option<LocationListEntry<R>>> {
567        loop {
568            let raw_loc = match self.raw.next()? {
569                Some(loc) => loc,
570                None => return Ok(None),
571            };
572
573            let loc = self.convert_raw(raw_loc)?;
574            if loc.is_some() {
575                return Ok(loc);
576            }
577        }
578    }
579
580    /// Return the next raw location.
581    ///
582    /// The raw location should be passed to `convert_raw`.
583    #[doc(hidden)]
584    pub fn next_raw(&mut self) -> Result<Option<RawLocListEntry<R>>> {
585        self.raw.next()
586    }
587
588    /// Convert a raw location into a location, and update the state of the iterator.
589    ///
590    /// The raw location should have been obtained from `next_raw`.
591    #[doc(hidden)]
592    pub fn convert_raw(
593        &mut self,
594        raw_loc: RawLocListEntry<R>,
595    ) -> Result<Option<LocationListEntry<R>>> {
596        let address_size = self.raw.encoding.address_size;
597        let mask = u64::ones_sized(address_size);
598        let tombstone = if self.raw.encoding.version <= 4 {
599            mask - 1
600        } else {
601            mask
602        };
603
604        let (range, data) = match raw_loc {
605            RawLocListEntry::BaseAddress { addr } => {
606                self.base_address = addr;
607                return Ok(None);
608            }
609            RawLocListEntry::BaseAddressx { addr } => {
610                self.base_address = self.get_address(addr)?;
611                return Ok(None);
612            }
613            RawLocListEntry::StartxEndx { begin, end, data } => {
614                let begin = self.get_address(begin)?;
615                let end = self.get_address(end)?;
616                (Range { begin, end }, data)
617            }
618            RawLocListEntry::StartxLength {
619                begin,
620                length,
621                data,
622            } => {
623                let begin = self.get_address(begin)?;
624                let end = begin.wrapping_add_sized(length, address_size);
625                (Range { begin, end }, data)
626            }
627            RawLocListEntry::DefaultLocation { data } => (
628                Range {
629                    begin: 0,
630                    end: u64::MAX,
631                },
632                data,
633            ),
634            RawLocListEntry::AddressOrOffsetPair { begin, end, data }
635            | RawLocListEntry::OffsetPair { begin, end, data } => {
636                // Skip tombstone entries (see below).
637                if self.base_address == tombstone {
638                    return Ok(None);
639                }
640                let mut range = Range { begin, end };
641                range.add_base_address(self.base_address, self.raw.encoding.address_size);
642                (range, data)
643            }
644            RawLocListEntry::StartEnd { begin, end, data } => (Range { begin, end }, data),
645            RawLocListEntry::StartLength {
646                begin,
647                length,
648                data,
649            } => {
650                let end = begin.wrapping_add_sized(length, address_size);
651                (Range { begin, end }, data)
652            }
653        };
654
655        // Skip tombstone entries.
656        //
657        // DWARF specifies a tombstone value of -1 or -2, but many linkers use 0 or 1.
658        // However, 0/1 may be a valid address, so we can't always reliably skip them.
659        // One case where we can skip them is for address pairs, where both values are
660        // replaced by tombstones and thus `begin` equals `end`. Since these entries
661        // are empty, it's safe to skip them even if they aren't tombstones.
662        //
663        // In addition to skipping tombstone entries, we also skip invalid entries
664        // where `begin` is greater than `end`. This can occur due to compiler bugs.
665        if range.begin == tombstone || range.begin >= range.end {
666            return Ok(None);
667        }
668
669        Ok(Some(LocationListEntry { range, data }))
670    }
671}
672
673#[cfg(feature = "fallible-iterator")]
674impl<R: Reader> fallible_iterator::FallibleIterator for LocListIter<R> {
675    type Item = LocationListEntry<R>;
676    type Error = Error;
677
678    fn next(&mut self) -> ::core::result::Result<Option<Self::Item>, Self::Error> {
679        LocListIter::next(self)
680    }
681}
682
683/// A location list entry from the `.debug_loc` or `.debug_loclists` sections.
684#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
685pub struct LocationListEntry<R: Reader> {
686    /// The address range that this location is valid for.
687    pub range: Range,
688
689    /// The data containing a single location description.
690    pub data: Expression<R>,
691}
692
693#[cfg(test)]
694mod tests {
695    use super::*;
696    use crate::common::Format;
697    use crate::constants::*;
698    use crate::endianity::LittleEndian;
699    use crate::read::{EndianSlice, Range};
700    use crate::test_util::GimliSectionMethods;
701    use alloc::vec::Vec;
702    use test_assembler::{Endian, Label, LabelMaker, Section};
703
704    #[test]
705    fn test_loclists() {
706        let format = Format::Dwarf32;
707        for size in [4, 8] {
708            let tombstone = u64::ones_sized(size);
709            let tombstone_0 = 0;
710            let encoding = Encoding {
711                format,
712                version: 5,
713                address_size: size,
714            };
715
716            let section = Section::with_endian(Endian::Little)
717                .word(size, 0x0300_0000)
718                .word(size, 0x0301_0300)
719                .word(size, 0x0301_0400)
720                .word(size, 0x0301_0500)
721                .word(size, tombstone)
722                .word(size, 0x0301_0600)
723                .word(size, tombstone_0);
724            let buf = section.get_contents().unwrap();
725            let debug_addr = &DebugAddr::from(EndianSlice::new(&buf, LittleEndian));
726            let debug_addr_base = DebugAddrBase(0);
727
728            let length = Label::new();
729            let start = Label::new();
730            let first = Label::new();
731            let end = Label::new();
732            let mut section = Section::with_endian(Endian::Little)
733                .initial_length(format, &length, &start)
734                .L16(encoding.version)
735                .L8(encoding.address_size)
736                .L8(0)
737                .L32(0)
738                .mark(&first);
739
740            let mut expected_locations = Vec::new();
741            let mut expect_location = |begin, end, data| {
742                expected_locations.push(LocationListEntry {
743                    range: Range { begin, end },
744                    data: Expression(EndianSlice::new(data, LittleEndian)),
745                });
746            };
747
748            // An offset pair using the unit base address.
749            section = section.L8(DW_LLE_offset_pair.0).uleb(0x10200).uleb(0x10300);
750            section = section.uleb(4).L32(2);
751            expect_location(0x0101_0200, 0x0101_0300, &[2, 0, 0, 0]);
752
753            section = section.L8(DW_LLE_base_address.0).word(size, 0x0200_0000);
754            section = section.L8(DW_LLE_offset_pair.0).uleb(0x10400).uleb(0x10500);
755            section = section.uleb(4).L32(3);
756            expect_location(0x0201_0400, 0x0201_0500, &[3, 0, 0, 0]);
757
758            section = section
759                .L8(DW_LLE_start_end.0)
760                .word(size, 0x201_0a00)
761                .word(size, 0x201_0b00);
762            section = section.uleb(4).L32(6);
763            expect_location(0x0201_0a00, 0x0201_0b00, &[6, 0, 0, 0]);
764
765            section = section
766                .L8(DW_LLE_start_length.0)
767                .word(size, 0x201_0c00)
768                .uleb(0x100);
769            section = section.uleb(4).L32(7);
770            expect_location(0x0201_0c00, 0x0201_0d00, &[7, 0, 0, 0]);
771
772            // An offset pair that starts at 0.
773            section = section.L8(DW_LLE_base_address.0).word(size, 0);
774            section = section.L8(DW_LLE_offset_pair.0).uleb(0).uleb(1);
775            section = section.uleb(4).L32(8);
776            expect_location(0, 1, &[8, 0, 0, 0]);
777
778            // An offset pair that ends at -1.
779            section = section.L8(DW_LLE_base_address.0).word(size, 0);
780            section = section.L8(DW_LLE_offset_pair.0).uleb(0).uleb(tombstone);
781            section = section.uleb(4).L32(9);
782            expect_location(0, tombstone, &[9, 0, 0, 0]);
783
784            section = section.L8(DW_LLE_default_location.0).uleb(4).L32(10);
785            expect_location(0, u64::MAX, &[10, 0, 0, 0]);
786
787            section = section.L8(DW_LLE_base_addressx.0).uleb(0);
788            section = section.L8(DW_LLE_offset_pair.0).uleb(0x10100).uleb(0x10200);
789            section = section.uleb(4).L32(11);
790            expect_location(0x0301_0100, 0x0301_0200, &[11, 0, 0, 0]);
791
792            section = section.L8(DW_LLE_startx_endx.0).uleb(1).uleb(2);
793            section = section.uleb(4).L32(12);
794            expect_location(0x0301_0300, 0x0301_0400, &[12, 0, 0, 0]);
795
796            section = section.L8(DW_LLE_startx_length.0).uleb(3).uleb(0x100);
797            section = section.uleb(4).L32(13);
798            expect_location(0x0301_0500, 0x0301_0600, &[13, 0, 0, 0]);
799
800            // Tombstone entries, all of which should be ignored.
801            section = section.L8(DW_LLE_base_addressx.0).uleb(4);
802            section = section.L8(DW_LLE_offset_pair.0).uleb(0x11100).uleb(0x11200);
803            section = section.uleb(4).L32(20);
804
805            section = section.L8(DW_LLE_base_address.0).word(size, tombstone);
806            section = section.L8(DW_LLE_offset_pair.0).uleb(0x11300).uleb(0x11400);
807            section = section.uleb(4).L32(21);
808
809            section = section.L8(DW_LLE_startx_endx.0).uleb(4).uleb(5);
810            section = section.uleb(4).L32(22);
811            section = section.L8(DW_LLE_startx_length.0).uleb(4).uleb(0x100);
812            section = section.uleb(4).L32(23);
813            section = section
814                .L8(DW_LLE_start_end.0)
815                .word(size, tombstone)
816                .word(size, 0x201_1500);
817            section = section.uleb(4).L32(24);
818            section = section
819                .L8(DW_LLE_start_length.0)
820                .word(size, tombstone)
821                .uleb(0x100);
822            section = section.uleb(4).L32(25);
823
824            // Ignore some instances of 0 for tombstone.
825            section = section.L8(DW_LLE_startx_endx.0).uleb(6).uleb(6);
826            section = section.uleb(4).L32(30);
827            section = section
828                .L8(DW_LLE_start_end.0)
829                .word(size, tombstone_0)
830                .word(size, tombstone_0);
831            section = section.uleb(4).L32(31);
832
833            // Ignore empty ranges.
834            section = section.L8(DW_LLE_base_address.0).word(size, 0);
835            section = section.L8(DW_LLE_offset_pair.0).uleb(0).uleb(0);
836            section = section.uleb(4).L32(41);
837            section = section.L8(DW_LLE_base_address.0).word(size, 0x10000);
838            section = section.L8(DW_LLE_offset_pair.0).uleb(0x1234).uleb(0x1234);
839            section = section.uleb(4).L32(42);
840
841            // A valid range after the tombstones.
842            section = section
843                .L8(DW_LLE_start_end.0)
844                .word(size, 0x201_1600)
845                .word(size, 0x201_1700);
846            section = section.uleb(4).L32(100);
847            expect_location(0x0201_1600, 0x0201_1700, &[100, 0, 0, 0]);
848
849            section = section.L8(DW_LLE_end_of_list.0);
850            section = section.mark(&end);
851            // Some extra data.
852            section = section.word(size, 0x1234_5678);
853            length.set_const((&end - &start) as u64);
854
855            let offset = LocationListsOffset((&first - &section.start()) as usize);
856            let buf = section.get_contents().unwrap();
857            let debug_loc = DebugLoc::new(&[], LittleEndian);
858            let debug_loclists = DebugLocLists::new(&buf, LittleEndian);
859            let loclists = LocationLists::new(debug_loc, debug_loclists);
860            let mut locations = loclists
861                .locations(offset, encoding, 0x0100_0000, debug_addr, debug_addr_base)
862                .unwrap();
863
864            for expected_location in expected_locations {
865                let location = locations.next();
866                assert_eq!(
867                    location,
868                    Ok(Some(expected_location)),
869                    "read {:x?}, expect {:x?}",
870                    location,
871                    expected_location
872                );
873            }
874            assert_eq!(locations.next(), Ok(None));
875        }
876    }
877
878    #[test]
879    fn test_location_list() {
880        for size in [4, 8] {
881            let base = u64::ones_sized(size);
882            let tombstone = u64::ones_sized(size) - 1;
883            let start = Label::new();
884            let first = Label::new();
885            let mut section = Section::with_endian(Endian::Little)
886                // A location before the offset.
887                .mark(&start)
888                .word(size, 0x10000)
889                .word(size, 0x10100)
890                .L16(4)
891                .L32(1)
892                .mark(&first);
893
894            let mut expected_locations = Vec::new();
895            let mut expect_location = |begin, end, data| {
896                expected_locations.push(LocationListEntry {
897                    range: Range { begin, end },
898                    data: Expression(EndianSlice::new(data, LittleEndian)),
899                });
900            };
901
902            // A normal location.
903            section = section.word(size, 0x10200).word(size, 0x10300);
904            section = section.L16(4).L32(2);
905            expect_location(0x0101_0200, 0x0101_0300, &[2, 0, 0, 0]);
906            // A base address selection followed by a normal location.
907            section = section.word(size, base).word(size, 0x0200_0000);
908            section = section.word(size, 0x10400).word(size, 0x10500);
909            section = section.L16(4).L32(3);
910            expect_location(0x0201_0400, 0x0201_0500, &[3, 0, 0, 0]);
911            // An empty location range followed by a normal location.
912            section = section.word(size, 0x10600).word(size, 0x10600);
913            section = section.L16(4).L32(4);
914            section = section.word(size, 0x10800).word(size, 0x10900);
915            section = section.L16(4).L32(5);
916            expect_location(0x0201_0800, 0x0201_0900, &[5, 0, 0, 0]);
917            // A location range that starts at 0.
918            section = section.word(size, base).word(size, 0);
919            section = section.word(size, 0).word(size, 1);
920            section = section.L16(4).L32(6);
921            expect_location(0, 1, &[6, 0, 0, 0]);
922            // A location range that ends at -1.
923            section = section.word(size, base).word(size, 0);
924            section = section.word(size, 0).word(size, base);
925            section = section.L16(4).L32(7);
926            expect_location(0, base, &[7, 0, 0, 0]);
927            // A normal location with tombstone.
928            section = section.word(size, tombstone).word(size, tombstone);
929            section = section.L16(4).L32(8);
930            // A base address selection with tombstone followed by a normal location.
931            section = section.word(size, base).word(size, tombstone);
932            section = section.word(size, 0x10a00).word(size, 0x10b00);
933            section = section.L16(4).L32(9);
934            // A location list end.
935            section = section.word(size, 0).word(size, 0);
936            // Some extra data.
937            section = section.word(size, 0x1234_5678);
938
939            let buf = section.get_contents().unwrap();
940            let debug_loc = DebugLoc::new(&buf, LittleEndian);
941            let debug_loclists = DebugLocLists::new(&[], LittleEndian);
942            let loclists = LocationLists::new(debug_loc, debug_loclists);
943            let offset = LocationListsOffset((&first - &start) as usize);
944            let debug_addr = &DebugAddr::from(EndianSlice::new(&[], LittleEndian));
945            let debug_addr_base = DebugAddrBase(0);
946            let encoding = Encoding {
947                format: Format::Dwarf32,
948                version: 4,
949                address_size: size,
950            };
951            let mut locations = loclists
952                .locations(offset, encoding, 0x0100_0000, debug_addr, debug_addr_base)
953                .unwrap();
954
955            for expected_location in expected_locations {
956                let location = locations.next();
957                assert_eq!(
958                    location,
959                    Ok(Some(expected_location)),
960                    "read {:x?}, expect {:x?}",
961                    location,
962                    expected_location
963                );
964            }
965            assert_eq!(locations.next(), Ok(None));
966
967            // An offset at the end of buf.
968            let mut locations = loclists
969                .locations(
970                    LocationListsOffset(buf.len()),
971                    encoding,
972                    0x0100_0000,
973                    debug_addr,
974                    debug_addr_base,
975                )
976                .unwrap();
977            assert_eq!(locations.next(), Ok(None));
978        }
979    }
980
981    #[test]
982    fn test_locations_invalid() {
983        #[rustfmt::skip]
984        let section = Section::with_endian(Endian::Little)
985            // An invalid location range.
986            .L32(0x20000).L32(0x10000).L16(4).L32(1)
987            // An invalid range after wrapping.
988            .L32(0x20000).L32(0xff01_0000).L16(4).L32(2);
989
990        let buf = section.get_contents().unwrap();
991        let debug_loc = DebugLoc::new(&buf, LittleEndian);
992        let debug_loclists = DebugLocLists::new(&[], LittleEndian);
993        let loclists = LocationLists::new(debug_loc, debug_loclists);
994        let debug_addr = &DebugAddr::from(EndianSlice::new(&[], LittleEndian));
995        let debug_addr_base = DebugAddrBase(0);
996        let encoding = Encoding {
997            format: Format::Dwarf32,
998            version: 4,
999            address_size: 4,
1000        };
1001
1002        // An invalid location range.
1003        let mut locations = loclists
1004            .locations(
1005                LocationListsOffset(0x0),
1006                encoding,
1007                0x0100_0000,
1008                debug_addr,
1009                debug_addr_base,
1010            )
1011            .unwrap();
1012        assert_eq!(locations.next(), Ok(None));
1013
1014        // An invalid location range after wrapping.
1015        let mut locations = loclists
1016            .locations(
1017                LocationListsOffset(14),
1018                encoding,
1019                0x0100_0000,
1020                debug_addr,
1021                debug_addr_base,
1022            )
1023            .unwrap();
1024        assert_eq!(locations.next(), Ok(None));
1025
1026        // An invalid offset.
1027        match loclists.locations(
1028            LocationListsOffset(buf.len() + 1),
1029            encoding,
1030            0x0100_0000,
1031            debug_addr,
1032            debug_addr_base,
1033        ) {
1034            Err(Error::UnexpectedEof(_)) => {}
1035            otherwise => panic!("Unexpected result: {:?}", otherwise),
1036        }
1037    }
1038
1039    #[test]
1040    fn test_get_offset() {
1041        for format in [Format::Dwarf32, Format::Dwarf64] {
1042            let encoding = Encoding {
1043                format,
1044                version: 5,
1045                address_size: 4,
1046            };
1047
1048            let zero = Label::new();
1049            let length = Label::new();
1050            let start = Label::new();
1051            let first = Label::new();
1052            let end = Label::new();
1053            let mut section = Section::with_endian(Endian::Little)
1054                .mark(&zero)
1055                .initial_length(format, &length, &start)
1056                .D16(encoding.version)
1057                .D8(encoding.address_size)
1058                .D8(0)
1059                .D32(20)
1060                .mark(&first);
1061            for i in 0..20 {
1062                section = section.word(format.word_size(), 1000 + i);
1063            }
1064            section = section.mark(&end);
1065            length.set_const((&end - &start) as u64);
1066            let section = section.get_contents().unwrap();
1067
1068            let debug_loc = DebugLoc::from(EndianSlice::new(&[], LittleEndian));
1069            let debug_loclists = DebugLocLists::from(EndianSlice::new(&section, LittleEndian));
1070            let locations = LocationLists::new(debug_loc, debug_loclists);
1071
1072            let base = DebugLocListsBase((&first - &zero) as usize);
1073            assert_eq!(
1074                locations.get_offset(encoding, base, DebugLocListsIndex(0)),
1075                Ok(LocationListsOffset(base.0 + 1000))
1076            );
1077            assert_eq!(
1078                locations.get_offset(encoding, base, DebugLocListsIndex(19)),
1079                Ok(LocationListsOffset(base.0 + 1019))
1080            );
1081        }
1082    }
1083
1084    #[test]
1085    fn test_loclists_gnu_v4_split_dwarf() {
1086        #[rustfmt::skip]
1087        let buf = [
1088            0x03, // DW_LLE_startx_length
1089            0x00, // ULEB encoded b7
1090            0x08, 0x00, 0x00, 0x00, // Fixed 4 byte length of 8
1091            0x03, 0x00, // Fixed two byte length of the location
1092            0x11, 0x00, // DW_OP_constu 0
1093            0x9f, // DW_OP_stack_value
1094            // Padding data
1095            //0x99, 0x99, 0x99, 0x99
1096        ];
1097        let data_buf = [0x11, 0x00, 0x9f];
1098        let expected_data = EndianSlice::new(&data_buf, LittleEndian);
1099        let debug_loc = DebugLoc::new(&buf, LittleEndian);
1100        let debug_loclists = DebugLocLists::new(&[], LittleEndian);
1101        let loclists = LocationLists::new(debug_loc, debug_loclists);
1102        let debug_addr =
1103            &DebugAddr::from(EndianSlice::new(&[0x01, 0x02, 0x03, 0x04], LittleEndian));
1104        let debug_addr_base = DebugAddrBase(0);
1105        let encoding = Encoding {
1106            format: Format::Dwarf32,
1107            version: 4,
1108            address_size: 4,
1109        };
1110
1111        // An invalid location range.
1112        let mut locations = loclists
1113            .locations_dwo(
1114                LocationListsOffset(0x0),
1115                encoding,
1116                0,
1117                debug_addr,
1118                debug_addr_base,
1119            )
1120            .unwrap();
1121        assert_eq!(
1122            locations.next(),
1123            Ok(Some(LocationListEntry {
1124                range: Range {
1125                    begin: 0x0403_0201,
1126                    end: 0x0403_0209
1127                },
1128                data: Expression(expected_data),
1129            }))
1130        );
1131    }
1132}
gimli/read/loclists.rs

gimli/read/
loclists.rs
