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use crate::common::{
DebugLineStrOffset, DebugStrOffset, DebugStrOffsetsBase, DebugStrOffsetsIndex, DwarfFileType,
Encoding, SectionId,
};
use crate::endianity::Endianity;
use crate::read::{EndianSlice, Reader, ReaderOffset, Result, Section};
use crate::Format;
/// The `DebugStr` struct represents the DWARF strings
/// found in the `.debug_str` section.
#[derive(Debug, Default, Clone, Copy)]
pub struct DebugStr<R> {
debug_str_section: R,
}
impl<'input, Endian> DebugStr<EndianSlice<'input, Endian>>
where
Endian: Endianity,
{
/// Construct a new `DebugStr` instance from the data in the `.debug_str`
/// section.
///
/// It is the caller's responsibility to read the `.debug_str` section and
/// present it as a `&[u8]` slice. That means using some ELF loader on
/// Linux, a Mach-O loader on macOS, etc.
///
/// ```
/// use gimli::{DebugStr, LittleEndian};
///
/// # let buf = [0x00, 0x01, 0x02, 0x03];
/// # let read_debug_str_section_somehow = || &buf;
/// let debug_str = DebugStr::new(read_debug_str_section_somehow(), LittleEndian);
/// ```
pub fn new(debug_str_section: &'input [u8], endian: Endian) -> Self {
Self::from(EndianSlice::new(debug_str_section, endian))
}
}
impl<R: Reader> DebugStr<R> {
/// Lookup a string from the `.debug_str` section by DebugStrOffset.
///
/// ```
/// use gimli::{DebugStr, DebugStrOffset, LittleEndian};
///
/// # let buf = [0x01, 0x02, 0x00];
/// # let offset = DebugStrOffset(0);
/// # let read_debug_str_section_somehow = || &buf;
/// # let debug_str_offset_somehow = || offset;
/// let debug_str = DebugStr::new(read_debug_str_section_somehow(), LittleEndian);
/// println!("Found string {:?}", debug_str.get_str(debug_str_offset_somehow()));
/// ```
pub fn get_str(&self, offset: DebugStrOffset<R::Offset>) -> Result<R> {
let input = &mut self.debug_str_section.clone();
input.skip(offset.0)?;
input.read_null_terminated_slice()
}
}
impl<T> DebugStr<T> {
/// Create a `DebugStr` section that references the data in `self`.
///
/// This is useful when `R` implements `Reader` but `T` does not.
///
/// Used by `DwarfSections::borrow`.
pub fn borrow<'a, F, R>(&'a self, mut borrow: F) -> DebugStr<R>
where
F: FnMut(&'a T) -> R,
{
borrow(&self.debug_str_section).into()
}
}
impl<R> Section<R> for DebugStr<R> {
fn id() -> SectionId {
SectionId::DebugStr
}
fn reader(&self) -> &R {
&self.debug_str_section
}
}
impl<R> From<R> for DebugStr<R> {
fn from(debug_str_section: R) -> Self {
DebugStr { debug_str_section }
}
}
/// The raw contents of the `.debug_str_offsets` section.
#[derive(Debug, Default, Clone, Copy)]
pub struct DebugStrOffsets<R> {
section: R,
}
impl<R: Reader> DebugStrOffsets<R> {
// TODO: add an iterator over the sets of entries in the section.
// This is not needed for common usage of the section though.
/// Returns the `.debug_str` offset at the given `base` and `index`.
///
/// A set of entries in the `.debug_str_offsets` section consists of a header
/// followed by a series of string table offsets.
///
/// The `base` must be the `DW_AT_str_offsets_base` value from the compilation unit DIE.
/// This is an offset that points to the first entry following the header.
///
/// The `index` is the value of a `DW_FORM_strx` attribute.
///
/// The `format` must be the DWARF format of the compilation unit. This format must
/// match the header. However, note that we do not parse the header to validate this,
/// since locating the header is unreliable, and the GNU extensions do not emit it.
pub fn get_str_offset(
&self,
format: Format,
base: DebugStrOffsetsBase<R::Offset>,
index: DebugStrOffsetsIndex<R::Offset>,
) -> Result<DebugStrOffset<R::Offset>> {
let input = &mut self.section.clone();
input.skip(base.0)?;
input.skip(R::Offset::from_u64(
index.0.into_u64() * u64::from(format.word_size()),
)?)?;
input.read_offset(format).map(DebugStrOffset)
}
}
impl<T> DebugStrOffsets<T> {
/// Create a `DebugStrOffsets` section that references the data in `self`.
///
/// This is useful when `R` implements `Reader` but `T` does not.
///
/// Used by `DwarfSections::borrow`.
pub fn borrow<'a, F, R>(&'a self, mut borrow: F) -> DebugStrOffsets<R>
where
F: FnMut(&'a T) -> R,
{
borrow(&self.section).into()
}
}
impl<R> Section<R> for DebugStrOffsets<R> {
fn id() -> SectionId {
SectionId::DebugStrOffsets
}
fn reader(&self) -> &R {
&self.section
}
}
impl<R> From<R> for DebugStrOffsets<R> {
fn from(section: R) -> Self {
DebugStrOffsets { section }
}
}
impl<Offset> DebugStrOffsetsBase<Offset>
where
Offset: ReaderOffset,
{
/// Returns a `DebugStrOffsetsBase` with the default value of DW_AT_str_offsets_base
/// for the given `Encoding` and `DwarfFileType`.
pub fn default_for_encoding_and_file(
encoding: Encoding,
file_type: DwarfFileType,
) -> DebugStrOffsetsBase<Offset> {
if encoding.version >= 5 && file_type == DwarfFileType::Dwo {
// In .dwo files, the compiler omits the DW_AT_str_offsets_base attribute (because there is
// only a single unit in the file) but we must skip past the header, which the attribute
// would normally do for us.
// initial_length_size + version + 2 bytes of padding.
DebugStrOffsetsBase(Offset::from_u8(
encoding.format.initial_length_size() + 2 + 2,
))
} else {
DebugStrOffsetsBase(Offset::from_u8(0))
}
}
}
/// The `DebugLineStr` struct represents the DWARF strings
/// found in the `.debug_line_str` section.
#[derive(Debug, Default, Clone, Copy)]
pub struct DebugLineStr<R> {
section: R,
}
impl<'input, Endian> DebugLineStr<EndianSlice<'input, Endian>>
where
Endian: Endianity,
{
/// Construct a new `DebugLineStr` instance from the data in the `.debug_line_str`
/// section.
///
/// It is the caller's responsibility to read the `.debug_line_str` section and
/// present it as a `&[u8]` slice. That means using some ELF loader on
/// Linux, a Mach-O loader on macOS, etc.
///
/// ```
/// use gimli::{DebugLineStr, LittleEndian};
///
/// # let buf = [0x00, 0x01, 0x02, 0x03];
/// # let read_debug_line_str_section_somehow = || &buf;
/// let debug_str = DebugLineStr::new(read_debug_line_str_section_somehow(), LittleEndian);
/// ```
pub fn new(debug_line_str_section: &'input [u8], endian: Endian) -> Self {
Self::from(EndianSlice::new(debug_line_str_section, endian))
}
}
impl<R: Reader> DebugLineStr<R> {
/// Lookup a string from the `.debug_line_str` section by DebugLineStrOffset.
pub fn get_str(&self, offset: DebugLineStrOffset<R::Offset>) -> Result<R> {
let input = &mut self.section.clone();
input.skip(offset.0)?;
input.read_null_terminated_slice()
}
}
impl<T> DebugLineStr<T> {
/// Create a `DebugLineStr` section that references the data in `self`.
///
/// This is useful when `R` implements `Reader` but `T` does not.
///
/// Used by `DwarfSections::borrow`.
pub fn borrow<'a, F, R>(&'a self, mut borrow: F) -> DebugLineStr<R>
where
F: FnMut(&'a T) -> R,
{
borrow(&self.section).into()
}
}
impl<R> Section<R> for DebugLineStr<R> {
fn id() -> SectionId {
SectionId::DebugLineStr
}
fn reader(&self) -> &R {
&self.section
}
}
impl<R> From<R> for DebugLineStr<R> {
fn from(section: R) -> Self {
DebugLineStr { section }
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::test_util::GimliSectionMethods;
use crate::LittleEndian;
use test_assembler::{Endian, Label, LabelMaker, Section};
#[test]
fn test_get_str_offset() {
for format in [Format::Dwarf32, Format::Dwarf64] {
let zero = Label::new();
let length = Label::new();
let start = Label::new();
let first = Label::new();
let end = Label::new();
let mut section = Section::with_endian(Endian::Little)
.mark(&zero)
.initial_length(format, &length, &start)
.D16(5)
.D16(0)
.mark(&first);
for i in 0..20 {
section = section.word(format.word_size(), 1000 + i);
}
section = section.mark(&end);
length.set_const((&end - &start) as u64);
let section = section.get_contents().unwrap();
let debug_str_offsets = DebugStrOffsets::from(EndianSlice::new(§ion, LittleEndian));
let base = DebugStrOffsetsBase((&first - &zero) as usize);
assert_eq!(
debug_str_offsets.get_str_offset(format, base, DebugStrOffsetsIndex(0)),
Ok(DebugStrOffset(1000))
);
assert_eq!(
debug_str_offsets.get_str_offset(format, base, DebugStrOffsetsIndex(19)),
Ok(DebugStrOffset(1019))
);
}
}
}