diff options
Diffstat (limited to 'vendor/gimli-0.26.2/src/read/lookup.rs')
| -rw-r--r-- | vendor/gimli-0.26.2/src/read/lookup.rs | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/vendor/gimli-0.26.2/src/read/lookup.rs b/vendor/gimli-0.26.2/src/read/lookup.rs new file mode 100644 index 000000000..1d082f24f --- /dev/null +++ b/vendor/gimli-0.26.2/src/read/lookup.rs @@ -0,0 +1,202 @@ +use core::marker::PhantomData; + +use crate::common::{DebugInfoOffset, Format}; +use crate::read::{parse_debug_info_offset, Error, Reader, ReaderOffset, Result, UnitOffset}; + +// The various "Accelerated Access" sections (DWARF standard v4 Section 6.1) all have +// similar structures. They consist of a header with metadata and an offset into the +// .debug_info section for the entire compilation unit, and a series +// of following entries that list addresses (for .debug_aranges) or names +// (for .debug_pubnames and .debug_pubtypes) that are covered. +// +// Because these three tables all have similar structures, we abstract out some of +// the parsing mechanics. + +pub trait LookupParser<R: Reader> { + /// The type of the produced header. + type Header; + /// The type of the produced entry. + type Entry; + + /// Parse a header from `input`. Returns a tuple of `input` sliced to contain just the entries + /// corresponding to this header (without the header itself), and the parsed representation of + /// the header itself. + fn parse_header(input: &mut R) -> Result<(R, Self::Header)>; + + /// Parse a single entry from `input`. Returns either a parsed representation of the entry + /// or None if `input` is exhausted. + fn parse_entry(input: &mut R, header: &Self::Header) -> Result<Option<Self::Entry>>; +} + +#[derive(Clone, Debug)] +pub struct DebugLookup<R, Parser> +where + R: Reader, + Parser: LookupParser<R>, +{ + input_buffer: R, + phantom: PhantomData<Parser>, +} + +impl<R, Parser> From<R> for DebugLookup<R, Parser> +where + R: Reader, + Parser: LookupParser<R>, +{ + fn from(input_buffer: R) -> Self { + DebugLookup { + input_buffer, + phantom: PhantomData, + } + } +} + +impl<R, Parser> DebugLookup<R, Parser> +where + R: Reader, + Parser: LookupParser<R>, +{ + pub fn items(&self) -> LookupEntryIter<R, Parser> { + LookupEntryIter { + current_set: None, + remaining_input: self.input_buffer.clone(), + } + } + + pub fn reader(&self) -> &R { + &self.input_buffer + } +} + +#[derive(Clone, Debug)] +pub struct LookupEntryIter<R, Parser> +where + R: Reader, + Parser: LookupParser<R>, +{ + current_set: Option<(R, Parser::Header)>, // Only none at the very beginning and end. + remaining_input: R, +} + +impl<R, Parser> LookupEntryIter<R, Parser> +where + R: Reader, + Parser: LookupParser<R>, +{ + /// Advance the iterator and return the next entry. + /// + /// Returns the newly parsed entry as `Ok(Some(Parser::Entry))`. Returns + /// `Ok(None)` when iteration is complete and all entries have already been + /// parsed and yielded. If an error occurs while parsing the next entry, + /// then this error is returned as `Err(e)`, and all subsequent calls return + /// `Ok(None)`. + /// + /// Can be [used with `FallibleIterator`](./index.html#using-with-fallibleiterator). + pub fn next(&mut self) -> Result<Option<Parser::Entry>> { + loop { + if let Some((ref mut input, ref header)) = self.current_set { + if !input.is_empty() { + match Parser::parse_entry(input, header) { + Ok(Some(entry)) => return Ok(Some(entry)), + Ok(None) => {} + Err(e) => { + input.empty(); + self.remaining_input.empty(); + return Err(e); + } + } + } + } + if self.remaining_input.is_empty() { + self.current_set = None; + return Ok(None); + } + match Parser::parse_header(&mut self.remaining_input) { + Ok(set) => { + self.current_set = Some(set); + } + Err(e) => { + self.current_set = None; + self.remaining_input.empty(); + return Err(e); + } + } + } + } +} + +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct PubStuffHeader<T = usize> { + format: Format, + length: T, + version: u16, + unit_offset: DebugInfoOffset<T>, + unit_length: T, +} + +pub trait PubStuffEntry<R: Reader> { + fn new( + die_offset: UnitOffset<R::Offset>, + name: R, + unit_header_offset: DebugInfoOffset<R::Offset>, + ) -> Self; +} + +#[derive(Clone, Debug)] +pub struct PubStuffParser<R, Entry> +where + R: Reader, + Entry: PubStuffEntry<R>, +{ + // This struct is never instantiated. + phantom: PhantomData<(R, Entry)>, +} + +impl<R, Entry> LookupParser<R> for PubStuffParser<R, Entry> +where + R: Reader, + Entry: PubStuffEntry<R>, +{ + type Header = PubStuffHeader<R::Offset>; + type Entry = Entry; + + /// Parse an pubthings set header. Returns a tuple of the + /// pubthings to be parsed for this set, and the newly created PubThingHeader struct. + fn parse_header(input: &mut R) -> Result<(R, Self::Header)> { + let (length, format) = input.read_initial_length()?; + let mut rest = input.split(length)?; + + let version = rest.read_u16()?; + if version != 2 { + return Err(Error::UnknownVersion(u64::from(version))); + } + + let unit_offset = parse_debug_info_offset(&mut rest, format)?; + let unit_length = rest.read_length(format)?; + + let header = PubStuffHeader { + format, + length, + version, + unit_offset, + unit_length, + }; + Ok((rest, header)) + } + + /// Parse a single pubthing. Return `None` for the null pubthing, `Some` for an actual pubthing. + fn parse_entry(input: &mut R, header: &Self::Header) -> Result<Option<Self::Entry>> { + let offset = input.read_offset(header.format)?; + if offset.into_u64() == 0 { + input.empty(); + Ok(None) + } else { + let name = input.read_null_terminated_slice()?; + Ok(Some(Self::Entry::new( + UnitOffset(offset), + name, + header.unit_offset, + ))) + } + } +} |