1 files changed, 218 insertions, 0 deletions
diff --git a/vendor/object/src/read/pe/import.rs b/vendor/object/src/read/pe/import.rs
new file mode 100644
index 000000000..809a96286
--- /dev/null
+++ b/vendor/object/src/read/pe/import.rs
@@ -0,0 +1,218 @@
+use core::fmt::Debug;
+use core::mem;
+
+use crate::read::{Bytes, ReadError, Result};
+use crate::{pe, LittleEndian as LE, Pod, U16Bytes};
+
+use super::ImageNtHeaders;
+
+/// Information for parsing a PE import table.
+#[derive(Debug, Clone)]
+pub struct ImportTable<'data> {
+    section_data: Bytes<'data>,
+    section_address: u32,
+    import_address: u32,
+}
+
+impl<'data> ImportTable<'data> {
+    /// Create a new import table parser.
+    ///
+    /// The import descriptors start at `import_address`.
+    /// The size declared in the `IMAGE_DIRECTORY_ENTRY_IMPORT` data directory is
+    /// ignored by the Windows loader, and so descriptors will be parsed until a null entry.
+    ///
+    /// `section_data` should be from the section containing `import_address`, and
+    /// `section_address` should be the address of that section. Pointers within the
+    /// descriptors and thunks may point to anywhere within the section data.
+    pub fn new(section_data: &'data [u8], section_address: u32, import_address: u32) -> Self {
+        ImportTable {
+            section_data: Bytes(section_data),
+            section_address,
+            import_address,
+        }
+    }
+
+    /// Return an iterator for the import descriptors.
+    pub fn descriptors(&self) -> Result<ImportDescriptorIterator<'data>> {
+        let offset = self.import_address.wrapping_sub(self.section_address);
+        let mut data = self.section_data;
+        data.skip(offset as usize)
+            .read_error("Invalid PE import descriptor address")?;
+        Ok(ImportDescriptorIterator { data })
+    }
+
+    /// Return a library name given its address.
+    ///
+    /// This address may be from [`pe::ImageImportDescriptor::name`].
+    pub fn name(&self, address: u32) -> Result<&'data [u8]> {
+        self.section_data
+            .read_string_at(address.wrapping_sub(self.section_address) as usize)
+            .read_error("Invalid PE import descriptor name")
+    }
+
+    /// Return a list of thunks given its address.
+    ///
+    /// This address may be from [`pe::ImageImportDescriptor::original_first_thunk`]
+    /// or [`pe::ImageImportDescriptor::first_thunk`].
+    pub fn thunks(&self, address: u32) -> Result<ImportThunkList<'data>> {
+        let offset = address.wrapping_sub(self.section_address);
+        let mut data = self.section_data;
+        data.skip(offset as usize)
+            .read_error("Invalid PE import thunk table address")?;
+        Ok(ImportThunkList { data })
+    }
+
+    /// Parse a thunk.
+    pub fn import<Pe: ImageNtHeaders>(&self, thunk: Pe::ImageThunkData) -> Result<Import<'data>> {
+        if thunk.is_ordinal() {
+            Ok(Import::Ordinal(thunk.ordinal()))
+        } else {
+            let (hint, name) = self.hint_name(thunk.address())?;
+            Ok(Import::Name(hint, name))
+        }
+    }
+
+    /// Return the hint and name at the given address.
+    ///
+    /// This address may be from [`pe::ImageThunkData32`] or [`pe::ImageThunkData64`].
+    ///
+    /// The hint is an index into the export name pointer table in the target library.
+    pub fn hint_name(&self, address: u32) -> Result<(u16, &'data [u8])> {
+        let offset = address.wrapping_sub(self.section_address);
+        let mut data = self.section_data;
+        data.skip(offset as usize)
+            .read_error("Invalid PE import thunk address")?;
+        let hint = data
+            .read::<U16Bytes<LE>>()
+            .read_error("Missing PE import thunk hint")?
+            .get(LE);
+        let name = data
+            .read_string()
+            .read_error("Missing PE import thunk name")?;
+        Ok((hint, name))
+    }
+}
+
+/// A fallible iterator for the descriptors in the import data directory.
+#[derive(Debug, Clone)]
+pub struct ImportDescriptorIterator<'data> {
+    data: Bytes<'data>,
+}
+
+impl<'data> ImportDescriptorIterator<'data> {
+    /// Return the next descriptor.
+    ///
+    /// Returns `Ok(None)` when a null descriptor is found.
+    pub fn next(&mut self) -> Result<Option<&'data pe::ImageImportDescriptor>> {
+        let import_desc = self
+            .data
+            .read::<pe::ImageImportDescriptor>()
+            .read_error("Missing PE null import descriptor")?;
+        if import_desc.is_null() {
+            Ok(None)
+        } else {
+            Ok(Some(import_desc))
+        }
+    }
+}
+
+/// A list of import thunks.
+///
+/// These may be in the import lookup table, or the import address table.
+#[derive(Debug, Clone)]
+pub struct ImportThunkList<'data> {
+    data: Bytes<'data>,
+}
+
+impl<'data> ImportThunkList<'data> {
+    /// Get the thunk at the given index.
+    pub fn get<Pe: ImageNtHeaders>(&self, index: usize) -> Result<Pe::ImageThunkData> {
+        let thunk = self
+            .data
+            .read_at(index * mem::size_of::<Pe::ImageThunkData>())
+            .read_error("Invalid PE import thunk index")?;
+        Ok(*thunk)
+    }
+
+    /// Return the first thunk in the list, and update `self` to point after it.
+    ///
+    /// Returns `Ok(None)` when a null thunk is found.
+    pub fn next<Pe: ImageNtHeaders>(&mut self) -> Result<Option<Pe::ImageThunkData>> {
+        let thunk = self
+            .data
+            .read::<Pe::ImageThunkData>()
+            .read_error("Missing PE null import thunk")?;
+        if thunk.address() == 0 {
+            Ok(None)
+        } else {
+            Ok(Some(*thunk))
+        }
+    }
+}
+
+/// A parsed import thunk.
+#[derive(Debug, Clone, Copy)]
+pub enum Import<'data> {
+    /// Import by ordinal.
+    Ordinal(u16),
+    /// Import by name.
+    ///
+    /// Includes a hint for the index into the export name pointer table in the target library.
+    Name(u16, &'data [u8]),
+}
+
+/// A trait for generic access to [`pe::ImageThunkData32`] and [`pe::ImageThunkData64`].
+#[allow(missing_docs)]
+pub trait ImageThunkData: Debug + Pod {
+    /// Return the raw thunk value.
+    fn raw(self) -> u64;
+
+    /// Returns true if the ordinal flag is set.
+    fn is_ordinal(self) -> bool;
+
+    /// Return the ordinal portion of the thunk.
+    ///
+    /// Does not check the ordinal flag.
+    fn ordinal(self) -> u16;
+
+    /// Return the RVA portion of the thunk.
+    ///
+    /// Does not check the ordinal flag.
+    fn address(self) -> u32;
+}
+
+impl ImageThunkData for pe::ImageThunkData64 {
+    fn raw(self) -> u64 {
+        self.0.get(LE)
+    }
+
+    fn is_ordinal(self) -> bool {
+        self.0.get(LE) & pe::IMAGE_ORDINAL_FLAG64 != 0
+    }
+
+    fn ordinal(self) -> u16 {
+        self.0.get(LE) as u16
+    }
+
+    fn address(self) -> u32 {
+        self.0.get(LE) as u32 & 0x7fff_ffff
+    }
+}
+
+impl ImageThunkData for pe::ImageThunkData32 {
+    fn raw(self) -> u64 {
+        self.0.get(LE).into()
+    }
+
+    fn is_ordinal(self) -> bool {
+        self.0.get(LE) & pe::IMAGE_ORDINAL_FLAG32 != 0
+    }
+
+    fn ordinal(self) -> u16 {
+        self.0.get(LE) as u16
+    }
+
+    fn address(self) -> u32 {
+        self.0.get(LE) & 0x7fff_ffff
+    }
+}