1 files changed, 303 insertions, 0 deletions
diff --git a/vendor/object/src/read/elf/attributes.rs b/vendor/object/src/read/elf/attributes.rs
new file mode 100644
index 000000000..6ec535d72
--- /dev/null
+++ b/vendor/object/src/read/elf/attributes.rs
@@ -0,0 +1,303 @@
+use core::convert::TryInto;
+
+use crate::elf;
+use crate::endian;
+use crate::read::{Bytes, Error, ReadError, Result};
+
+use super::FileHeader;
+
+/// An ELF attributes section.
+///
+/// This may be a GNU attributes section, or an architecture specific attributes section.
+///
+/// An attributes section contains a series of subsections.
+#[derive(Debug, Clone)]
+pub struct AttributesSection<'data, Elf: FileHeader> {
+    endian: Elf::Endian,
+    version: u8,
+    data: Bytes<'data>,
+}
+
+impl<'data, Elf: FileHeader> AttributesSection<'data, Elf> {
+    /// Parse an ELF attributes section given the section data.
+    pub fn new(endian: Elf::Endian, data: &'data [u8]) -> Result<Self> {
+        let mut data = Bytes(data);
+
+        // Skip the version field that is one byte long.
+        let version = *data
+            .read::<u8>()
+            .read_error("Invalid ELF attributes section offset or size")?;
+
+        Ok(AttributesSection {
+            endian,
+            version,
+            data,
+        })
+    }
+
+    /// Return the version of the attributes section.
+    pub fn version(&self) -> u8 {
+        self.version
+    }
+
+    /// Return an iterator over the subsections.
+    pub fn subsections(&self) -> Result<AttributesSubsectionIterator<'data, Elf>> {
+        // There is currently only one format version.
+        if self.version != b'A' {
+            return Err(Error("Unsupported ELF attributes section version"));
+        }
+
+        Ok(AttributesSubsectionIterator {
+            endian: self.endian,
+            data: self.data,
+        })
+    }
+}
+
+/// An iterator over the subsections in an ELF attributes section.
+#[derive(Debug, Clone)]
+pub struct AttributesSubsectionIterator<'data, Elf: FileHeader> {
+    endian: Elf::Endian,
+    data: Bytes<'data>,
+}
+
+impl<'data, Elf: FileHeader> AttributesSubsectionIterator<'data, Elf> {
+    /// Return the next subsection.
+    pub fn next(&mut self) -> Result<Option<AttributesSubsection<'data, Elf>>> {
+        if self.data.is_empty() {
+            return Ok(None);
+        }
+
+        let result = self.parse();
+        if result.is_err() {
+            self.data = Bytes(&[]);
+        }
+        result
+    }
+
+    fn parse(&mut self) -> Result<Option<AttributesSubsection<'data, Elf>>> {
+        // First read the subsection length.
+        let mut data = self.data;
+        let length = data
+            .read::<endian::U32Bytes<Elf::Endian>>()
+            .read_error("ELF attributes section is too short")?
+            .get(self.endian);
+
+        // Now read the entire subsection, updating self.data.
+        let mut data = self
+            .data
+            .read_bytes(length as usize)
+            .read_error("Invalid ELF attributes subsection length")?;
+        // Skip the subsection length field.
+        data.skip(4)
+            .read_error("Invalid ELF attributes subsection length")?;
+
+        let vendor = data
+            .read_string()
+            .read_error("Invalid ELF attributes vendor")?;
+
+        Ok(Some(AttributesSubsection {
+            endian: self.endian,
+            length,
+            vendor,
+            data,
+        }))
+    }
+}
+
+/// A subsection in an ELF attributes section.
+///
+/// A subsection is identified by a vendor name.  It contains a series of sub-subsections.
+#[derive(Debug, Clone)]
+pub struct AttributesSubsection<'data, Elf: FileHeader> {
+    endian: Elf::Endian,
+    length: u32,
+    vendor: &'data [u8],
+    data: Bytes<'data>,
+}
+
+impl<'data, Elf: FileHeader> AttributesSubsection<'data, Elf> {
+    /// Return the length of the attributes subsection.
+    pub fn length(&self) -> u32 {
+        self.length
+    }
+
+    /// Return the vendor name of the attributes subsection.
+    pub fn vendor(&self) -> &'data [u8] {
+        self.vendor
+    }
+
+    /// Return an iterator over the sub-subsections.
+    pub fn subsubsections(&self) -> AttributesSubsubsectionIterator<'data, Elf> {
+        AttributesSubsubsectionIterator {
+            endian: self.endian,
+            data: self.data,
+        }
+    }
+}
+
+/// An iterator over the sub-subsections in an ELF attributes section.
+#[derive(Debug, Clone)]
+pub struct AttributesSubsubsectionIterator<'data, Elf: FileHeader> {
+    endian: Elf::Endian,
+    data: Bytes<'data>,
+}
+
+impl<'data, Elf: FileHeader> AttributesSubsubsectionIterator<'data, Elf> {
+    /// Return the next sub-subsection.
+    pub fn next(&mut self) -> Result<Option<AttributesSubsubsection<'data>>> {
+        if self.data.is_empty() {
+            return Ok(None);
+        }
+
+        let result = self.parse();
+        if result.is_err() {
+            self.data = Bytes(&[]);
+        }
+        result
+    }
+
+    fn parse(&mut self) -> Result<Option<AttributesSubsubsection<'data>>> {
+        // The format of a sub-section looks like this:
+        //
+        // <file-tag> <size> <attribute>*
+        // | <section-tag> <size> <section-number>* 0 <attribute>*
+        // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
+        let mut data = self.data;
+        let tag = *data
+            .read::<u8>()
+            .read_error("ELF attributes subsection is too short")?;
+        let length = data
+            .read::<endian::U32Bytes<Elf::Endian>>()
+            .read_error("ELF attributes subsection is too short")?
+            .get(self.endian);
+
+        // Now read the entire sub-subsection, updating self.data.
+        let mut data = self
+            .data
+            .read_bytes(length as usize)
+            .read_error("Invalid ELF attributes sub-subsection length")?;
+        // Skip the tag and sub-subsection size field.
+        data.skip(1 + 4)
+            .read_error("Invalid ELF attributes sub-subsection length")?;
+
+        let indices = if tag == elf::Tag_Section || tag == elf::Tag_Symbol {
+            data.read_string()
+                .map(Bytes)
+                .read_error("Missing ELF attributes sub-subsection indices")?
+        } else if tag == elf::Tag_File {
+            Bytes(&[])
+        } else {
+            return Err(Error("Unimplemented ELF attributes sub-subsection tag"));
+        };
+
+        Ok(Some(AttributesSubsubsection {
+            tag,
+            length,
+            indices,
+            data,
+        }))
+    }
+}
+
+/// A sub-subsection in an ELF attributes section.
+///
+/// A sub-subsection is identified by a tag.  It contains an optional series of indices,
+/// followed by a series of attributes.
+#[derive(Debug, Clone)]
+pub struct AttributesSubsubsection<'data> {
+    tag: u8,
+    length: u32,
+    indices: Bytes<'data>,
+    data: Bytes<'data>,
+}
+
+impl<'data> AttributesSubsubsection<'data> {
+    /// Return the tag of the attributes sub-subsection.
+    pub fn tag(&self) -> u8 {
+        self.tag
+    }
+
+    /// Return the length of the attributes sub-subsection.
+    pub fn length(&self) -> u32 {
+        self.length
+    }
+
+    /// Return the data containing the indices.
+    pub fn indices_data(&self) -> &'data [u8] {
+        self.indices.0
+    }
+
+    /// Return the indices.
+    ///
+    /// This will be section indices if the tag is `Tag_Section`,
+    /// or symbol indices if the tag is `Tag_Symbol`,
+    /// and otherwise it will be empty.
+    pub fn indices(&self) -> AttributeIndexIterator<'data> {
+        AttributeIndexIterator { data: self.indices }
+    }
+
+    /// Return the data containing the attributes.
+    pub fn attributes_data(&self) -> &'data [u8] {
+        self.data.0
+    }
+
+    /// Return a parser for the data containing the attributes.
+    pub fn attributes(&self) -> AttributeReader<'data> {
+        AttributeReader { data: self.data }
+    }
+}
+
+/// An iterator over the indices in a sub-subsection in an ELF attributes section.
+#[derive(Debug, Clone)]
+pub struct AttributeIndexIterator<'data> {
+    data: Bytes<'data>,
+}
+
+impl<'data> AttributeIndexIterator<'data> {
+    /// Parse the next index.
+    pub fn next(&mut self) -> Result<Option<u32>> {
+        if self.data.is_empty() {
+            return Ok(None);
+        }
+        let err = "Invalid ELF attribute index";
+        self.data
+            .read_uleb128()
+            .read_error(err)?
+            .try_into()
+            .map_err(|_| ())
+            .read_error(err)
+            .map(Some)
+    }
+}
+
+/// A parser for the attributes in a sub-subsection in an ELF attributes section.
+///
+/// The parser relies on the caller to know the format of the data for each attribute tag.
+#[derive(Debug, Clone)]
+pub struct AttributeReader<'data> {
+    data: Bytes<'data>,
+}
+
+impl<'data> AttributeReader<'data> {
+    /// Parse a tag.
+    pub fn read_tag(&mut self) -> Result<Option<u64>> {
+        if self.data.is_empty() {
+            return Ok(None);
+        }
+        let err = "Invalid ELF attribute tag";
+        self.data.read_uleb128().read_error(err).map(Some)
+    }
+
+    /// Parse an integer value.
+    pub fn read_integer(&mut self) -> Result<u64> {
+        let err = "Invalid ELF attribute integer value";
+        self.data.read_uleb128().read_error(err)
+    }
+
+    /// Parse a string value.
+    pub fn read_string(&mut self) -> Result<&'data [u8]> {
+        let err = "Invalid ELF attribute string value";
+        self.data.read_string().read_error(err)
+    }
+}