thorin/
ext.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
use gimli::{Encoding, EndianSlice, RunTimeEndian, UnitIndex};
use object::{Endianness, ObjectSection};

use crate::{relocate::RelocationMap, Session};

/// Helper trait to translate between `object`'s `Endianness` and `gimli`'s `RunTimeEndian`.
pub(crate) trait EndianityExt {
    fn as_runtime_endian(&self) -> RunTimeEndian;
}

impl EndianityExt for Endianness {
    fn as_runtime_endian(&self) -> RunTimeEndian {
        match *self {
            Endianness::Little => RunTimeEndian::Little,
            Endianness::Big => RunTimeEndian::Big,
        }
    }
}

/// Helper trait to add `compressed_data_range` function to `ObjectSection` types.
pub(crate) trait CompressedDataRangeExt<'input, 'session: 'input>:
    ObjectSection<'input>
{
    /// Return the decompressed contents of the section data in the given range.
    ///
    /// Decompression happens only if the data is compressed.
    fn compressed_data_range(
        &self,
        sess: &'session impl Session<RelocationMap>,
        address: u64,
        size: u64,
    ) -> object::Result<Option<&'input [u8]>>;
}

impl<'input, 'session: 'input, S> CompressedDataRangeExt<'input, 'session> for S
where
    S: ObjectSection<'input>,
{
    fn compressed_data_range(
        &self,
        sess: &'session impl Session<RelocationMap>,
        address: u64,
        size: u64,
    ) -> object::Result<Option<&'input [u8]>> {
        let data = self.compressed_data()?.decompress()?;

        /// Originally from `object::read::util`, used in `ObjectSection::data_range`, but not
        /// public.
        fn data_range(
            data: &[u8],
            data_address: u64,
            range_address: u64,
            size: u64,
        ) -> Option<&[u8]> {
            let offset = range_address.checked_sub(data_address)?;
            data.get(offset.try_into().ok()?..)?.get(..size.try_into().ok()?)
        }

        let data_ref = sess.alloc_owned_cow(data);
        Ok(data_range(data_ref, self.address(), address, size))
    }
}

/// Helper trait that abstracts over `gimli::DebugCuIndex` and `gimli::DebugTuIndex`.
pub(crate) trait IndexSectionExt<'input, Endian: gimli::Endianity, R: gimli::Reader>:
    gimli::Section<R>
{
    fn new(section: &'input [u8], endian: Endian) -> Self;

    fn index(self) -> gimli::read::Result<UnitIndex<R>>;
}

impl<'input, Endian: gimli::Endianity> IndexSectionExt<'input, Endian, EndianSlice<'input, Endian>>
    for gimli::DebugCuIndex<EndianSlice<'input, Endian>>
{
    fn new(section: &'input [u8], endian: Endian) -> Self {
        Self::new(section, endian)
    }

    fn index(self) -> gimli::read::Result<UnitIndex<EndianSlice<'input, Endian>>> {
        Self::index(self)
    }
}

impl<'input, Endian: gimli::Endianity> IndexSectionExt<'input, Endian, EndianSlice<'input, Endian>>
    for gimli::DebugTuIndex<EndianSlice<'input, Endian>>
{
    fn new(section: &'input [u8], endian: Endian) -> Self {
        Self::new(section, endian)
    }

    fn index(self) -> gimli::read::Result<UnitIndex<EndianSlice<'input, Endian>>> {
        Self::index(self)
    }
}

/// Helper trait to add DWARF package specific functions to the `Encoding` type.
pub(crate) trait PackageFormatExt {
    /// Returns `true` if this `Encoding` would produce to a DWARF 5-standardized package file.
    ///
    /// See Sec 7.3.5 and Appendix F of the [DWARF specification].
    ///
    /// [DWARF specification]: https://dwarfstd.org/doc/DWARF5.pdf
    fn is_std_dwarf_package_format(&self) -> bool;

    /// Returns `true` if this `Encoding` would produce a GNU Extension DWARF package file
    /// (preceded standardized version from DWARF 5).
    ///
    /// See [specification](https://gcc.gnu.org/wiki/DebugFissionDWP).
    fn is_gnu_extension_dwarf_package_format(&self) -> bool;

    /// Returns index version of DWARF package for this `Encoding`.
    fn dwarf_package_index_version(&self) -> u16;

    /// Returns `true` if the dwarf package index version provided is compatible with this
    /// `Encoding`.
    fn is_compatible_dwarf_package_index_version(&self, index_version: u16) -> bool;
}

impl PackageFormatExt for Encoding {
    fn is_gnu_extension_dwarf_package_format(&self) -> bool {
        !self.is_std_dwarf_package_format()
    }

    fn is_std_dwarf_package_format(&self) -> bool {
        self.version >= 5
    }

    fn dwarf_package_index_version(&self) -> u16 {
        if self.is_gnu_extension_dwarf_package_format() {
            2
        } else {
            5
        }
    }

    fn is_compatible_dwarf_package_index_version(&self, index_version: u16) -> bool {
        if self.is_gnu_extension_dwarf_package_format() {
            index_version == 2
        } else {
            index_version >= 5
        }
    }
}