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#![deny(missing_docs)]
use endianity::{Endianity, EndianBuf};
use parser::{parse_u16, parse_uN_as_u64, parse_unit_length, parse_debug_info_offset,
parse_address_size, DebugInfoOffset, Format, ParseResult, Error};
use std::cmp::Ordering;
use std::marker::PhantomData;
use std::rc::Rc;
/// The `DebugAranges` struct represents the DWARF address range information
/// found in the `.debug_aranges` section.
#[derive(Debug, Clone, Copy)]
pub struct DebugAranges<'input, Endian>
where Endian: Endianity
{
debug_aranges_section: EndianBuf<'input, Endian>,
}
impl<'input, Endian> DebugAranges<'input, Endian>
where Endian: Endianity
{
/// Construct a new `DebugAranges` instance from the data in the `.debug_aranges`
/// section.
///
/// It is the caller's responsibility to read the `.debug_aranges` section and
/// present it as a `&[u8]` slice. That means using some ELF loader on
/// Linux, a Mach-O loader on OSX, etc.
///
/// ```
/// use gimli::{DebugAranges, LittleEndian};
///
/// # let buf = [];
/// # let read_debug_aranges_section_somehow = || &buf;
/// let debug_aranges = DebugAranges::<LittleEndian>::new(read_debug_aranges_section_somehow());
/// ```
pub fn new(debug_aranges_section: &'input [u8]) -> DebugAranges<'input, Endian> {
DebugAranges { debug_aranges_section: EndianBuf(debug_aranges_section, PhantomData) }
}
/// Iterate the aranges in the `.debug_aranges` section.
/// ```
/// use gimli{DebugAranges, LittleEndian};
///
/// # let buf = [];
/// # let read_debug_aranges_section_somehow = || &buf;
/// let debug_aranges = DebugAranges::<LittleEndian>::new(read_debug_aranges_section_somehow());
///
/// for parse_result in debug_aranges.aranges() {
/// let arange = parse_result.unwrap();
/// println!("arange starts at {}, has length {}", arange.start(), arange.len());
/// }
/// ```
pub fn aranges(&self) -> ArangeEntryIter<Endian> {
ArangeEntryIter {
current_header: None,
current_set: EndianBuf::new(&[]),
remaining_input: self.debug_aranges_section,
}
}
}
/// An iterator over the aranges from a .debug_aranges section.
pub struct ArangeEntryIter<'input, Endian>
where Endian: Endianity
{
current_header: Option<Rc<ArangeHeader>>, // Only none at the very beginning and end.
current_set: EndianBuf<'input, Endian>,
remaining_input: EndianBuf<'input, Endian>,
}
impl<'input, Endian> ArangeEntryIter<'input, Endian>
where Endian: Endianity
{
/// Advance the iterator and return the next arange.
///
/// Returns the newly parsed arange as `Ok(Some(arange))`. Returns
/// `Ok(None)` when iteration is complete and all aranges have already been
/// parsed and yielded. If an error occurs while parsing the next arange,
/// then this error is returned on all subsequent calls as `Err(e)`.
pub fn next_arange(&mut self) -> ParseResult<Option<ArangeEntry>> {
if self.current_set.is_empty() {
if self.remaining_input.is_empty() {
self.current_header = None;
Ok(None)
} else {
// Parse the next header.
match ArangeEntry::parse_header(self.remaining_input) {
Ok((input, set, header)) => {
self.remaining_input = input;
self.current_set = set;
self.current_header = Some(header);
// Header is parsed, go parse the first entry.
self.next_arange()
}
Err(e) => {
self.remaining_input = self.remaining_input.range_to(..0);
self.current_header = None;
Err(e)
}
}
}
} else {
match ArangeEntry::parse_one(self.current_set,
self.current_header
.as_ref()
.expect("How did this happen?")) {
Ok((remaining_set, arange)) => {
self.current_set = remaining_set;
match arange {
None => {
// Last entry for this header, go around again and parse a new header.
// NB: There could be padding, so we must explicitly truncate current_set.
self.current_set = self.current_set.range_to(..0);
self.next_arange()
}
Some(arange) => Ok(Some(arange)),
}
}
Err(e) => {
self.current_set = self.current_set.range_to(..0);
self.current_header = None;
// Should we blow away all other arange sets too? Maybe not ...
self.remaining_input = self.remaining_input.range_to(..0);
Err(e)
}
}
}
}
}
#[derive(Debug, PartialEq, Eq)]
struct ArangeHeader {
format: Format,
length: u64,
version: u16,
offset: DebugInfoOffset,
address_size: u8,
segment_size: u8,
}
/// A single parsed arange.
#[derive(Debug, Clone, Eq)]
pub struct ArangeEntry {
segment: u64,
offset: u64,
length: u64,
header: Rc<ArangeHeader>,
}
impl ArangeEntry {
/// Parse an arange set header. Returns a tuple of the remaining arange sets, the aranges to be
/// parsed for this set, and the newly created ArangeHeader struct.
fn parse_header<Endian>
(input: EndianBuf<Endian>)
-> ParseResult<(EndianBuf<Endian>, EndianBuf<Endian>, Rc<ArangeHeader>)>
where Endian: Endianity
{
let (rest, (length, format)) = try!(parse_unit_length(input.into()));
let (rest, version) = try!(parse_u16(rest.into()));
if version != 2 {
return Err(Error::UnknownVersion);
}
let (rest, offset) = try!(parse_debug_info_offset(rest.into(), format));
let (rest, address_size) = try!(parse_address_size(rest.into()));
let (rest, segment_size) = try!(parse_address_size(rest.into()));
let header_length = match format {
Format::Dwarf32 => 8,
Format::Dwarf64 => 12,
};
let dividing_line: usize = try!(length.checked_sub(header_length)
.ok_or(Error::BadLength)) as usize;
Ok((rest.range_from(dividing_line..),
rest.range_to(..dividing_line),
Rc::new(ArangeHeader {
format: format,
length: length,
version: version,
offset: offset,
address_size: address_size,
segment_size: segment_size,
})))
}
/// Parse a single arange. Return `None` for the null arange, `Some` for an actual arange.
fn parse_one<'input, Endian>(input: EndianBuf<'input, Endian>,
header: &Rc<ArangeHeader>)
-> ParseResult<(EndianBuf<'input, Endian>, Option<ArangeEntry>)>
where Endian: Endianity
{
let address_size = header.address_size;
let segment_size = header.segment_size; // May be zero!
let (rest, segment) = try!(parse_uN_as_u64(segment_size, input));
let (rest, offset) = try!(parse_uN_as_u64(address_size, rest));
let (rest, length) = try!(parse_uN_as_u64(address_size, rest));
Ok((rest,
match (segment, offset, length) {
(0, 0, 0) => None,
_ => {
Some(ArangeEntry {
segment: segment,
offset: offset,
length: length,
header: header.clone(),
})
}
}))
}
/// Return the beginning address of this arange.
pub fn start(&self) -> u64 {
debug_assert!(self.segment == 0); // Dunno what to do with this
self.offset
}
/// Return the length of this arange.
pub fn len(&self) -> u64 {
self.length
}
/// Return the offset into the .debug_info section for this arange.
pub fn debug_info_offset(&self) -> DebugInfoOffset {
self.header.offset
}
}
impl PartialEq for ArangeEntry {
fn eq(&self, other: &ArangeEntry) -> bool {
// The expected comparison, but verify that header matches if everything else does.
match (self.segment == other.segment,
self.offset == other.offset,
self.length == other.length) {
(true, true, true) => {
debug_assert!(self.header == other.header);
true
}
_ => false,
}
}
}
impl PartialOrd for ArangeEntry {
fn partial_cmp(&self, other: &ArangeEntry) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for ArangeEntry {
fn cmp(&self, other: &ArangeEntry) -> Ordering {
// The expected comparison, but ignore header.
match (self.segment.cmp(&other.segment),
self.offset.cmp(&other.offset),
self.length.cmp(&other.length)) {
(Ordering::Equal, Ordering::Equal, Ordering::Equal) => Ordering::Equal,
(Ordering::Less, _, _) |
(Ordering::Equal, Ordering::Less, _) |
(Ordering::Equal, Ordering::Equal, Ordering::Less) => Ordering::Less,
(Ordering::Greater, _, _) |
(Ordering::Equal, Ordering::Greater, _) |
(Ordering::Equal, Ordering::Equal, Ordering::Greater) => Ordering::Greater,
}
}
}