1 files changed, 88 insertions, 0 deletions
diff --git a/third_party/rust/wasmparser/src/readers/function_section.rs b/third_party/rust/wasmparser/src/readers/function_section.rs
new file mode 100644
index 0000000000..0d96cf2f92
--- /dev/null
+++ b/third_party/rust/wasmparser/src/readers/function_section.rs
@@ -0,0 +1,88 @@
+/* Copyright 2018 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use super::{
+    BinaryReader, Range, Result, SectionIteratorLimited, SectionReader, SectionWithLimitedItems,
+};
+
+#[derive(Clone)]
+pub struct FunctionSectionReader<'a> {
+    reader: BinaryReader<'a>,
+    count: u32,
+}
+
+impl<'a> FunctionSectionReader<'a> {
+    pub fn new(data: &'a [u8], offset: usize) -> Result<FunctionSectionReader<'a>> {
+        let mut reader = BinaryReader::new_with_offset(data, offset);
+        let count = reader.read_var_u32()?;
+        Ok(FunctionSectionReader { reader, count })
+    }
+
+    pub fn original_position(&self) -> usize {
+        self.reader.original_position()
+    }
+
+    pub fn get_count(&self) -> u32 {
+        self.count
+    }
+
+    /// Reads function type index from the function section.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use wasmparser::FunctionSectionReader;
+    /// # let data: &[u8] = &[0x01, 0x00];
+    /// let mut function_reader = FunctionSectionReader::new(data, 0).unwrap();
+    /// for _ in 0..function_reader.get_count() {
+    ///     let ty = function_reader.read().expect("function type index");
+    ///     println!("Function type index: {}", ty);
+    /// }
+    /// ```
+    pub fn read(&mut self) -> Result<u32> {
+        self.reader.read_var_u32()
+    }
+}
+
+impl<'a> SectionReader for FunctionSectionReader<'a> {
+    type Item = u32;
+    fn read(&mut self) -> Result<Self::Item> {
+        FunctionSectionReader::read(self)
+    }
+    fn eof(&self) -> bool {
+        self.reader.eof()
+    }
+    fn original_position(&self) -> usize {
+        FunctionSectionReader::original_position(self)
+    }
+    fn range(&self) -> Range {
+        self.reader.range()
+    }
+}
+
+impl<'a> SectionWithLimitedItems for FunctionSectionReader<'a> {
+    fn get_count(&self) -> u32 {
+        FunctionSectionReader::get_count(self)
+    }
+}
+
+impl<'a> IntoIterator for FunctionSectionReader<'a> {
+    type Item = Result<u32>;
+    type IntoIter = SectionIteratorLimited<FunctionSectionReader<'a>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        SectionIteratorLimited::new(self)
+    }
+}