1 files changed, 162 insertions, 0 deletions
diff --git a/third_party/rust/object/src/read/elf/comdat.rs b/third_party/rust/object/src/read/elf/comdat.rs
new file mode 100644
index 0000000000..7cee85bb44
--- /dev/null
+++ b/third_party/rust/object/src/read/elf/comdat.rs
@@ -0,0 +1,162 @@
+use core::fmt::Debug;
+use core::{iter, slice, str};
+
+use crate::elf;
+use crate::endian::{Endianness, U32Bytes};
+use crate::read::{self, ComdatKind, ObjectComdat, ReadError, ReadRef, SectionIndex, SymbolIndex};
+
+use super::{ElfFile, FileHeader, SectionHeader, Sym};
+
+/// An iterator over the COMDAT section groups of an `ElfFile32`.
+pub type ElfComdatIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    ElfComdatIterator<'data, 'file, elf::FileHeader32<Endian>, R>;
+/// An iterator over the COMDAT section groups of an `ElfFile64`.
+pub type ElfComdatIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    ElfComdatIterator<'data, 'file, elf::FileHeader64<Endian>, R>;
+
+/// An iterator over the COMDAT section groups of an `ElfFile`.
+#[derive(Debug)]
+pub struct ElfComdatIterator<'data, 'file, Elf, R = &'data [u8]>
+where
+    'data: 'file,
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    pub(super) file: &'file ElfFile<'data, Elf, R>,
+    pub(super) iter: iter::Enumerate<slice::Iter<'data, Elf::SectionHeader>>,
+}
+
+impl<'data, 'file, Elf, R> Iterator for ElfComdatIterator<'data, 'file, Elf, R>
+where
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    type Item = ElfComdat<'data, 'file, Elf, R>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        for (_index, section) in self.iter.by_ref() {
+            if let Some(comdat) = ElfComdat::parse(self.file, section) {
+                return Some(comdat);
+            }
+        }
+        None
+    }
+}
+
+/// A COMDAT section group of an `ElfFile32`.
+pub type ElfComdat32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    ElfComdat<'data, 'file, elf::FileHeader32<Endian>, R>;
+/// A COMDAT section group of an `ElfFile64`.
+pub type ElfComdat64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    ElfComdat<'data, 'file, elf::FileHeader64<Endian>, R>;
+
+/// A COMDAT section group of an `ElfFile`.
+#[derive(Debug)]
+pub struct ElfComdat<'data, 'file, Elf, R = &'data [u8]>
+where
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    file: &'file ElfFile<'data, Elf, R>,
+    section: &'data Elf::SectionHeader,
+    sections: &'data [U32Bytes<Elf::Endian>],
+}
+
+impl<'data, 'file, Elf, R> ElfComdat<'data, 'file, Elf, R>
+where
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    fn parse(
+        file: &'file ElfFile<'data, Elf, R>,
+        section: &'data Elf::SectionHeader,
+    ) -> Option<ElfComdat<'data, 'file, Elf, R>> {
+        let (flag, sections) = section.group(file.endian, file.data).ok()??;
+        if flag != elf::GRP_COMDAT {
+            return None;
+        }
+        Some(ElfComdat {
+            file,
+            section,
+            sections,
+        })
+    }
+}
+
+impl<'data, 'file, Elf, R> read::private::Sealed for ElfComdat<'data, 'file, Elf, R>
+where
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+}
+
+impl<'data, 'file, Elf, R> ObjectComdat<'data> for ElfComdat<'data, 'file, Elf, R>
+where
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    type SectionIterator = ElfComdatSectionIterator<'data, 'file, Elf, R>;
+
+    #[inline]
+    fn kind(&self) -> ComdatKind {
+        ComdatKind::Any
+    }
+
+    #[inline]
+    fn symbol(&self) -> SymbolIndex {
+        SymbolIndex(self.section.sh_info(self.file.endian) as usize)
+    }
+
+    fn name_bytes(&self) -> read::Result<&[u8]> {
+        // FIXME: check sh_link
+        let index = self.section.sh_info(self.file.endian) as usize;
+        let symbol = self.file.symbols.symbol(index)?;
+        symbol.name(self.file.endian, self.file.symbols.strings())
+    }
+
+    fn name(&self) -> read::Result<&str> {
+        let name = self.name_bytes()?;
+        str::from_utf8(name)
+            .ok()
+            .read_error("Non UTF-8 ELF COMDAT name")
+    }
+
+    fn sections(&self) -> Self::SectionIterator {
+        ElfComdatSectionIterator {
+            file: self.file,
+            sections: self.sections.iter(),
+        }
+    }
+}
+
+/// An iterator over the sections in a COMDAT section group of an `ElfFile32`.
+pub type ElfComdatSectionIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    ElfComdatSectionIterator<'data, 'file, elf::FileHeader32<Endian>, R>;
+/// An iterator over the sections in a COMDAT section group of an `ElfFile64`.
+pub type ElfComdatSectionIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> =
+    ElfComdatSectionIterator<'data, 'file, elf::FileHeader64<Endian>, R>;
+
+/// An iterator over the sections in a COMDAT section group of an `ElfFile`.
+#[derive(Debug)]
+pub struct ElfComdatSectionIterator<'data, 'file, Elf, R = &'data [u8]>
+where
+    'data: 'file,
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    file: &'file ElfFile<'data, Elf, R>,
+    sections: slice::Iter<'data, U32Bytes<Elf::Endian>>,
+}
+
+impl<'data, 'file, Elf, R> Iterator for ElfComdatSectionIterator<'data, 'file, Elf, R>
+where
+    Elf: FileHeader,
+    R: ReadRef<'data>,
+{
+    type Item = SectionIndex;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let index = self.sections.next()?;
+        Some(SectionIndex(index.get(self.file.endian) as usize))
+    }
+}