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ld/dwarf: remove reader resets

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DWARF reader never had to reverse. Readers are already copied to achieve this effect.
Plus the position that it reverses to might be questionable.
This commit is contained in:
occheung 2024-11-28 16:39:58 +08:00 committed by sb10q
parent fce61f7b8c
commit 71dec251e3
1 changed files with 11 additions and 18 deletions
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29
nac3ld/src/dwarf.rs
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@ -27,23 +27,16 @@ pub const DW_EH_PE_indirect: u8 = 0x80;
pub struct DwarfReader<'a> {
pub slice: &'a [u8],
pub virt_addr: u32,
base_slice: &'a [u8],
base_virt_addr: u32,
}
impl<'a> DwarfReader<'a> {
pub fn new(slice: &[u8], virt_addr: u32) -> DwarfReader {
DwarfReader { slice, virt_addr, base_slice: slice, base_virt_addr: virt_addr }
DwarfReader { slice, virt_addr }
}
/// Creates a new instance from another instance of [DwarfReader], optionally removing any
/// offsets previously applied to the other instance.
pub fn from_reader(other: &DwarfReader<'a>, reset_offset: bool) -> DwarfReader<'a> {
if reset_offset {
DwarfReader::new(other.base_slice, other.base_virt_addr)
} else {
DwarfReader::new(other.slice, other.virt_addr)
}
/// Creates a new instance from another instance of [DwarfReader].
pub fn from_reader(other: &DwarfReader<'a>) -> DwarfReader<'a> {
DwarfReader::new(other.slice, other.virt_addr)
}
pub fn offset(&mut self, offset: u32) {
@ -228,7 +221,7 @@ impl<'a> EH_Frame<'a> {
/// Returns an [Iterator] over all Call Frame Information (CFI) records.
pub fn cfi_records(&self) -> CFI_Records<'a> {
let reader = DwarfReader::from_reader(&self.reader, true);
let reader = DwarfReader::from_reader(&self.reader);
let len = reader.slice.len();
CFI_Records { reader, available: len }
@ -259,7 +252,7 @@ impl<'a> CFI_Record<'a> {
0xFFFF_FFFF => unimplemented!(),
_ => {
let mut fde_reader = DwarfReader::from_reader(cie_reader, false);
let mut fde_reader = DwarfReader::from_reader(cie_reader);
fde_reader.offset(length);
fde_reader
}
@ -278,7 +271,7 @@ impl<'a> CFI_Record<'a> {
// Skip code/data alignment factors & return address register along the way as well
// We only tackle the case where 'z' and 'R' are part of the augmentation string, otherwise
// we cannot get the addresses to make .eh_frame_hdr
let mut aug_data_reader = DwarfReader::from_reader(cie_reader, false);
let mut aug_data_reader = DwarfReader::from_reader(cie_reader);
let mut aug_str_len = 0;
loop {
if aug_data_reader.read_u8() == b'\0' {
@ -321,7 +314,7 @@ impl<'a> CFI_Record<'a> {
/// Returns a [DwarfReader] initialized to the first Frame Description Entry (FDE) of this CFI
/// record.
pub fn get_fde_reader(&self) -> DwarfReader<'a> {
DwarfReader::from_reader(&self.fde_reader, false)
DwarfReader::from_reader(&self.fde_reader)
}
/// Returns an [Iterator] over all Frame Description Entries (FDEs).
@ -349,7 +342,7 @@ impl<'a> Iterator for CFI_Records<'a> {
return None;
}
let mut this_reader = DwarfReader::from_reader(&self.reader, false);
let mut this_reader = DwarfReader::from_reader(&self.reader);
// Remove the length of the header and the content from the counter
let length = self.reader.read_u32();
@ -362,7 +355,7 @@ impl<'a> Iterator for CFI_Records<'a> {
// Remove the length of the header and the content from the counter
self.available -= length + mem::size_of::<u32>();
let mut next_reader = DwarfReader::from_reader(&self.reader, false);
let mut next_reader = DwarfReader::from_reader(&self.reader);
next_reader.offset(length as u32);
let cie_ptr = self.reader.read_u32();
@ -410,7 +403,7 @@ impl<'a> Iterator for FDE_Records<'a> {
// Remove the length of the header and the content from the counter
self.available -= length + mem::size_of::<u32>();
let mut next_fde_reader = DwarfReader::from_reader(&self.reader, false);
let mut next_fde_reader = DwarfReader::from_reader(&self.reader);
next_fde_reader.offset(length as u32);
let cie_ptr = self.reader.read_u32();