1 files changed, 90 insertions, 0 deletions
diff --git a/third_party/rust/object/src/read/pe/relocation.rs b/third_party/rust/object/src/read/pe/relocation.rs
new file mode 100644
index 0000000000..06215bd1a7
--- /dev/null
+++ b/third_party/rust/object/src/read/pe/relocation.rs
@@ -0,0 +1,90 @@
+use core::slice;
+
+use crate::endian::{LittleEndian as LE, U16};
+use crate::pe;
+use crate::read::{Bytes, Error, ReadError, Result};
+
+/// An iterator over the relocation blocks in the `.reloc` section of a PE file.
+#[derive(Debug, Default, Clone, Copy)]
+pub struct RelocationBlockIterator<'data> {
+    data: Bytes<'data>,
+}
+
+impl<'data> RelocationBlockIterator<'data> {
+    /// Construct a new iterator from the data of the `.reloc` section.
+    pub fn new(data: &'data [u8]) -> Self {
+        RelocationBlockIterator { data: Bytes(data) }
+    }
+
+    /// Read the next relocation page.
+    pub fn next(&mut self) -> Result<Option<RelocationIterator<'data>>> {
+        if self.data.is_empty() {
+            return Ok(None);
+        }
+        let header = self
+            .data
+            .read::<pe::ImageBaseRelocation>()
+            .read_error("Invalid PE reloc section size")?;
+        let virtual_address = header.virtual_address.get(LE);
+        let size = header.size_of_block.get(LE);
+        if size <= 8 || size & 3 != 0 {
+            return Err(Error("Invalid PE reloc block size"));
+        }
+        let count = (size - 8) / 2;
+        let relocs = self
+            .data
+            .read_slice::<U16<LE>>(count as usize)
+            .read_error("Invalid PE reloc block size")?
+            .iter();
+        Ok(Some(RelocationIterator {
+            virtual_address,
+            size,
+            relocs,
+        }))
+    }
+}
+
+/// An iterator of the relocations in a block in the `.reloc` section of a PE file.
+#[derive(Debug, Clone)]
+pub struct RelocationIterator<'data> {
+    virtual_address: u32,
+    size: u32,
+    relocs: slice::Iter<'data, U16<LE>>,
+}
+
+impl<'data> RelocationIterator<'data> {
+    /// Return the virtual address of the page that this block of relocations applies to.
+    pub fn virtual_address(&self) -> u32 {
+        self.virtual_address
+    }
+
+    /// Return the size in bytes of this block of relocations.
+    pub fn size(&self) -> u32 {
+        self.size
+    }
+}
+
+impl<'data> Iterator for RelocationIterator<'data> {
+    type Item = Relocation;
+
+    fn next(&mut self) -> Option<Relocation> {
+        loop {
+            let reloc = self.relocs.next()?.get(LE);
+            if reloc != 0 {
+                return Some(Relocation {
+                    virtual_address: self.virtual_address.wrapping_add((reloc & 0xfff) as u32),
+                    typ: reloc >> 12,
+                });
+            }
+        }
+    }
+}
+
+/// A relocation in the `.reloc` section of a PE file.
+#[derive(Debug, Default, Clone, Copy)]
+pub struct Relocation {
+    /// The virtual address of the relocation.
+    pub virtual_address: u32,
+    /// One of the `pe::IMAGE_REL_BASED_*` constants.
+    pub typ: u16,
+}