gimli/read/
addr.rs

1use crate::common::{DebugAddrBase, DebugAddrIndex, DebugAddrOffset, Encoding, SectionId};
2use crate::read::{Error, Reader, ReaderOffset, Result, Section};
3
4/// The raw contents of the `.debug_addr` section.
5#[derive(Debug, Default, Clone, Copy)]
6pub struct DebugAddr<R> {
7    section: R,
8}
9
10impl<R: Reader> DebugAddr<R> {
11    /// Returns the address at the given `base` and `index`.
12    ///
13    /// A set of addresses in the `.debug_addr` section consists of a header
14    /// followed by a series of addresses.
15    ///
16    /// The `base` must be the `DW_AT_addr_base` value from the compilation unit DIE.
17    /// This is an offset that points to the first address following the header.
18    ///
19    /// The `index` is the value of a `DW_FORM_addrx` attribute.
20    ///
21    /// The `address_size` must be the size of the address for the compilation unit.
22    /// This value must also match the header. However, note that we do not parse the
23    /// header to validate this, since locating the header is unreliable, and the GNU
24    /// extensions do not emit it.
25    pub fn get_address(
26        &self,
27        address_size: u8,
28        base: DebugAddrBase<R::Offset>,
29        index: DebugAddrIndex<R::Offset>,
30    ) -> Result<u64> {
31        let input = &mut self.section.clone();
32        input.skip(base.0)?;
33        input.skip(R::Offset::from_u64(
34            index.0.into_u64() * u64::from(address_size),
35        )?)?;
36        input.read_address(address_size)
37    }
38
39    /// Iterate the sets of entries in the `.debug_addr` section.
40    ///
41    /// Each set of entries belongs to a single unit.
42    pub fn headers(&self) -> AddrHeaderIter<R> {
43        AddrHeaderIter {
44            input: self.section.clone(),
45            offset: DebugAddrOffset(R::Offset::from_u8(0)),
46        }
47    }
48}
49
50impl<T> DebugAddr<T> {
51    /// Create a `DebugAddr` section that references the data in `self`.
52    ///
53    /// This is useful when `R` implements `Reader` but `T` does not.
54    ///
55    /// Used by `DwarfSections::borrow`.
56    pub fn borrow<'a, F, R>(&'a self, mut borrow: F) -> DebugAddr<R>
57    where
58        F: FnMut(&'a T) -> R,
59    {
60        borrow(&self.section).into()
61    }
62}
63
64impl<R> Section<R> for DebugAddr<R> {
65    fn id() -> SectionId {
66        SectionId::DebugAddr
67    }
68
69    fn reader(&self) -> &R {
70        &self.section
71    }
72}
73
74impl<R> From<R> for DebugAddr<R> {
75    fn from(section: R) -> Self {
76        DebugAddr { section }
77    }
78}
79
80/// An iterator over the headers of a `.debug_addr` section.
81#[derive(Clone, Debug)]
82pub struct AddrHeaderIter<R: Reader> {
83    input: R,
84    offset: DebugAddrOffset<R::Offset>,
85}
86
87impl<R: Reader> AddrHeaderIter<R> {
88    /// Advance the iterator to the next header.
89    pub fn next(&mut self) -> Result<Option<AddrHeader<R>>> {
90        if self.input.is_empty() {
91            return Ok(None);
92        }
93
94        let len = self.input.len();
95        match AddrHeader::parse(&mut self.input, self.offset) {
96            Ok(header) => {
97                self.offset.0 += len - self.input.len();
98                Ok(Some(header))
99            }
100            Err(e) => {
101                self.input.empty();
102                Err(e)
103            }
104        }
105    }
106}
107
108#[cfg(feature = "fallible-iterator")]
109impl<R: Reader> fallible_iterator::FallibleIterator for AddrHeaderIter<R> {
110    type Item = AddrHeader<R>;
111    type Error = Error;
112
113    fn next(&mut self) -> ::core::result::Result<Option<Self::Item>, Self::Error> {
114        AddrHeaderIter::next(self)
115    }
116}
117
118/// A header for a set of entries in the `.debug_addr` section.
119///
120/// These entries all belong to a single unit.
121#[derive(Debug, Clone, PartialEq, Eq)]
122pub struct AddrHeader<R, Offset = <R as Reader>::Offset>
123where
124    R: Reader<Offset = Offset>,
125    Offset: ReaderOffset,
126{
127    offset: DebugAddrOffset<Offset>,
128    encoding: Encoding,
129    length: Offset,
130    entries: R,
131}
132
133impl<R, Offset> AddrHeader<R, Offset>
134where
135    R: Reader<Offset = Offset>,
136    Offset: ReaderOffset,
137{
138    fn parse(input: &mut R, offset: DebugAddrOffset<Offset>) -> Result<Self> {
139        let (length, format) = input.read_initial_length()?;
140        let mut rest = input.split(length)?;
141
142        // Check the version. The DWARF 5 spec says that this is always 5.
143        let version = rest.read_u16()?;
144        if version != 5 {
145            return Err(Error::UnknownVersion(u64::from(version)));
146        }
147
148        let address_size = rest.read_address_size()?;
149        let segment_size = rest.read_u8()?;
150        if segment_size != 0 {
151            return Err(Error::UnsupportedSegmentSize);
152        }
153
154        // unit_length + version + address_size + segment_size
155        let header_length = format.initial_length_size() + 2 + 1 + 1;
156
157        // The first tuple following the header in each set begins at an offset that is
158        // a multiple of the size of a single tuple (that is, the size of a segment,
159        // which must be zero, and an address).
160        let tuple_length = address_size;
161        if tuple_length == 0 {
162            return Err(Error::UnsupportedAddressSize(address_size));
163        }
164        let padding = if header_length % tuple_length == 0 {
165            0
166        } else {
167            tuple_length - header_length % tuple_length
168        };
169        rest.skip(R::Offset::from_u8(padding))?;
170
171        let encoding = Encoding {
172            format,
173            version,
174            address_size,
175        };
176        Ok(AddrHeader {
177            offset,
178            encoding,
179            length,
180            entries: rest,
181        })
182    }
183
184    /// Return the offset of this header within the `.debug_addr` section.
185    #[inline]
186    pub fn offset(&self) -> DebugAddrOffset<Offset> {
187        self.offset
188    }
189
190    /// Return the length of this set of entries, including the header.
191    #[inline]
192    pub fn length(&self) -> Offset {
193        self.length
194    }
195
196    /// Return the encoding parameters for this set of entries.
197    #[inline]
198    pub fn encoding(&self) -> Encoding {
199        self.encoding
200    }
201
202    /// Return the address entries in this set.
203    #[inline]
204    pub fn entries(&self) -> AddrEntryIter<R> {
205        AddrEntryIter {
206            input: self.entries.clone(),
207            encoding: self.encoding,
208        }
209    }
210}
211
212/// An iterator over the addresses from a `.debug_addr` section.
213///
214/// Can be [used with
215/// `FallibleIterator`](./index.html#using-with-fallibleiterator).
216#[derive(Debug, Clone)]
217pub struct AddrEntryIter<R: Reader> {
218    input: R,
219    encoding: Encoding,
220}
221
222impl<R: Reader> AddrEntryIter<R> {
223    /// Advance the iterator and return the next address.
224    ///
225    /// Returns the newly parsed address as `Ok(Some(addr))`. Returns `Ok(None)`
226    /// when iteration is complete and all addresses have already been parsed and
227    /// yielded. If an error occurs while parsing the next address, then this error
228    /// is returned as `Err(e)`, and all subsequent calls return `Ok(None)`.
229    pub fn next(&mut self) -> Result<Option<u64>> {
230        if self.input.is_empty() {
231            return Ok(None);
232        }
233
234        match self.input.read_address(self.encoding.address_size) {
235            Ok(entry) => Ok(Some(entry)),
236            Err(e) => {
237                self.input.empty();
238                Err(e)
239            }
240        }
241    }
242}
243
244#[cfg(feature = "fallible-iterator")]
245impl<R: Reader> fallible_iterator::FallibleIterator for AddrEntryIter<R> {
246    type Item = u64;
247    type Error = Error;
248
249    fn next(&mut self) -> ::core::result::Result<Option<Self::Item>, Self::Error> {
250        AddrEntryIter::next(self)
251    }
252}
253
254#[cfg(test)]
255mod tests {
256    use super::*;
257    use crate::read::EndianSlice;
258    use crate::test_util::GimliSectionMethods;
259    use crate::{Format, LittleEndian};
260    use test_assembler::{Endian, Label, LabelMaker, Section};
261
262    #[test]
263    fn test_get_address() {
264        for format in [Format::Dwarf32, Format::Dwarf64] {
265            for address_size in [4, 8] {
266                let zero = Label::new();
267                let length = Label::new();
268                let start = Label::new();
269                let first = Label::new();
270                let end = Label::new();
271                let mut section = Section::with_endian(Endian::Little)
272                    .mark(&zero)
273                    .initial_length(format, &length, &start)
274                    .D16(5)
275                    .D8(address_size)
276                    .D8(0)
277                    .mark(&first);
278                for i in 0..20 {
279                    section = section.word(address_size, 1000 + i);
280                }
281                section = section.mark(&end);
282                length.set_const((&end - &start) as u64);
283
284                let section = section.get_contents().unwrap();
285                let debug_addr = DebugAddr::from(EndianSlice::new(&section, LittleEndian));
286                let base = DebugAddrBase((&first - &zero) as usize);
287
288                assert_eq!(
289                    debug_addr.get_address(address_size, base, DebugAddrIndex(0)),
290                    Ok(1000)
291                );
292                assert_eq!(
293                    debug_addr.get_address(address_size, base, DebugAddrIndex(19)),
294                    Ok(1019)
295                );
296            }
297        }
298    }
299
300    #[test]
301    fn test_iterator() {
302        let length = Label::new();
303        let start = Label::new();
304        let end = Label::new();
305        // First CU.
306        let mut section = Section::with_endian(Endian::Little)
307            .initial_length(Format::Dwarf32, &length, &start)
308            .D16(5) // Version
309            .D8(4) // Address size
310            .D8(0) // Segment size
311            .word(4, 0x12345678)
312            .word(4, 0xdeadbeef)
313            .mark(&end);
314        length.set_const((&end - &start) as u64);
315        // Second CU.
316        let length = Label::new();
317        let start = Label::new();
318        let end = Label::new();
319        section = section
320            .initial_length(Format::Dwarf64, &length, &start)
321            .D16(5) // Version
322            .D8(8) // Address size
323            .D8(0) // Segment size
324            .word(8, 0x123456789abcdef0)
325            .word(8, 0xdeadbeefdeadbeef)
326            .mark(&end);
327        length.set_const((&end - &start) as u64);
328        let section = section.get_contents().unwrap();
329        let debug_addr = DebugAddr::from(EndianSlice::new(&section, LittleEndian));
330        let mut iter = debug_addr.headers();
331        let first_header = iter.next().unwrap().unwrap();
332        let first_encoding = first_header.encoding();
333        assert_eq!(first_encoding.address_size, 4);
334        assert_eq!(first_encoding.format, Format::Dwarf32);
335        assert_eq!(first_encoding.version, 5);
336        assert_eq!(first_header.length(), 12);
337        let mut first_entries = first_header.entries();
338        assert_eq!(first_entries.next(), Ok(Some(0x12345678)));
339        assert_eq!(first_entries.next(), Ok(Some(0xdeadbeef)));
340        assert_eq!(first_entries.next(), Ok(None));
341        let second_header = iter.next().unwrap().unwrap();
342        let second_encoding = second_header.encoding();
343        assert_eq!(second_encoding.address_size, 8);
344        assert_eq!(second_encoding.format, Format::Dwarf64);
345        assert_eq!(second_encoding.version, 5);
346        assert_eq!(second_header.length(), 20);
347        let mut second_entries = second_header.entries();
348        assert_eq!(second_entries.next(), Ok(Some(0x123456789abcdef0)));
349        assert_eq!(second_entries.next(), Ok(Some(0xdeadbeefdeadbeef)));
350        assert_eq!(second_entries.next(), Ok(None));
351        assert_eq!(iter.next(), Ok(None));
352    }
353}
gimli/read/addr.rs

gimli/read/
addr.rs
