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Diffstat (limited to 'vendor/gimli/src/read/str.rs')
| -rw-r--r-- | vendor/gimli/src/read/str.rs | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/vendor/gimli/src/read/str.rs b/vendor/gimli/src/read/str.rs new file mode 100644 index 0000000..c6b87d8 --- /dev/null +++ b/vendor/gimli/src/read/str.rs @@ -0,0 +1,321 @@ +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. + /// + /// ## Example Usage + /// + /// ```rust,no_run + /// # let load_section = || unimplemented!(); + /// // Read the DWARF section into a `Vec` with whatever object loader you're using. + /// let owned_section: gimli::DebugStr<Vec<u8>> = load_section(); + /// // Create a reference to the DWARF section. + /// let section = owned_section.borrow(|section| { + /// gimli::EndianSlice::new(§ion, gimli::LittleEndian) + /// }); + /// ``` + 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. + /// + /// ## Example Usage + /// + /// ```rust,no_run + /// # let load_section = || unimplemented!(); + /// // Read the DWARF section into a `Vec` with whatever object loader you're using. + /// let owned_section: gimli::DebugStrOffsets<Vec<u8>> = load_section(); + /// // Create a reference to the DWARF section. + /// let section = owned_section.borrow(|section| { + /// gimli::EndianSlice::new(§ion, gimli::LittleEndian) + /// }); + /// ``` + 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. + /// + /// ## Example Usage + /// + /// ```rust,no_run + /// # let load_section = || unimplemented!(); + /// // Read the DWARF section into a `Vec` with whatever object loader you're using. + /// let owned_section: gimli::DebugLineStr<Vec<u8>> = load_section(); + /// // Create a reference to the DWARF section. + /// let section = owned_section.borrow(|section| { + /// gimli::EndianSlice::new(§ion, gimli::LittleEndian) + /// }); + /// ``` + 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 vec![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)) + ); + } + } +} |