blob: 2bc91951b49fd81842bced26d67dddb496079c56 (
plain)
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
|
//! Utilities for parsing DWARF-encoded data streams.
//! See <http://www.dwarfstd.org>,
//! DWARF-4 standard, Section 7 - "Data Representation"
// This module is used only by x86_64-pc-windows-gnu for now, but we
// are compiling it everywhere to avoid regressions.
#![allow(unused)]
#![forbid(unsafe_op_in_unsafe_fn)]
#[cfg(test)]
mod tests;
pub mod eh;
pub struct DwarfReader {
pub ptr: *const u8,
}
impl DwarfReader {
pub fn new(ptr: *const u8) -> DwarfReader {
DwarfReader { ptr }
}
/// Read a type T and then bump the pointer by that amount.
///
/// DWARF streams are "packed", so all types must be read at align 1.
pub unsafe fn read<T: Copy>(&mut self) -> T {
unsafe {
let result = self.ptr.cast::<T>().read_unaligned();
self.ptr = self.ptr.byte_add(size_of::<T>());
result
}
}
/// ULEB128 and SLEB128 encodings are defined in Section 7.6 - "Variable Length Data".
pub unsafe fn read_uleb128(&mut self) -> u64 {
let mut shift: usize = 0;
let mut result: u64 = 0;
let mut byte: u8;
loop {
byte = unsafe { self.read::<u8>() };
result |= ((byte & 0x7F) as u64) << shift;
shift += 7;
if byte & 0x80 == 0 {
break;
}
}
result
}
pub unsafe fn read_sleb128(&mut self) -> i64 {
let mut shift: u32 = 0;
let mut result: u64 = 0;
let mut byte: u8;
loop {
byte = unsafe { self.read::<u8>() };
result |= ((byte & 0x7F) as u64) << shift;
shift += 7;
if byte & 0x80 == 0 {
break;
}
}
// sign-extend
if shift < u64::BITS && (byte & 0x40) != 0 {
result |= (!0 as u64) << shift;
}
result as i64
}
}
|
