1 files changed, 197 insertions, 0 deletions
diff --git a/third_party/rust/wasmparser/src/readers/producers_section.rs b/third_party/rust/wasmparser/src/readers/producers_section.rs
new file mode 100644
index 0000000000..d6a9051b16
--- /dev/null
+++ b/third_party/rust/wasmparser/src/readers/producers_section.rs
@@ -0,0 +1,197 @@
+/* Copyright 2019 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(Debug, Copy, Clone)]
+pub struct ProducersFieldValue<'a> {
+    pub name: &'a str,
+    pub version: &'a str,
+}
+
+pub struct ProducersFieldValuesReader<'a> {
+    reader: BinaryReader<'a>,
+    count: u32,
+}
+
+impl<'a> ProducersFieldValuesReader<'a> {
+    pub fn get_count(&self) -> u32 {
+        self.count
+    }
+
+    pub fn original_position(&self) -> usize {
+        self.reader.original_position()
+    }
+
+    fn skip(reader: &mut BinaryReader, values_count: u32) -> Result<()> {
+        for _ in 0..values_count {
+            reader.skip_string()?;
+            reader.skip_string()?;
+        }
+        Ok(())
+    }
+
+    pub fn read<'b>(&mut self) -> Result<ProducersFieldValue<'b>>
+    where
+        'a: 'b,
+    {
+        let name = self.reader.read_string()?;
+        let version = self.reader.read_string()?;
+        Ok(ProducersFieldValue { name, version })
+    }
+}
+
+impl<'a> IntoIterator for ProducersFieldValuesReader<'a> {
+    type Item = Result<ProducersFieldValue<'a>>;
+    type IntoIter = ProducersFieldValuesIterator<'a>;
+    fn into_iter(self) -> Self::IntoIter {
+        let count = self.count;
+        ProducersFieldValuesIterator {
+            reader: self,
+            left: count,
+            err: false,
+        }
+    }
+}
+
+pub struct ProducersFieldValuesIterator<'a> {
+    reader: ProducersFieldValuesReader<'a>,
+    left: u32,
+    err: bool,
+}
+
+impl<'a> Iterator for ProducersFieldValuesIterator<'a> {
+    type Item = Result<ProducersFieldValue<'a>>;
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.err || self.left == 0 {
+            return None;
+        }
+        let result = self.reader.read();
+        self.err = result.is_err();
+        self.left -= 1;
+        Some(result)
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let count = self.reader.get_count() as usize;
+        (count, Some(count))
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct ProducersField<'a> {
+    pub name: &'a str,
+    values_count: u32,
+    values_data: &'a [u8],
+    values_offset: usize,
+}
+
+impl<'a> ProducersField<'a> {
+    pub fn get_producer_field_values_reader<'b>(&self) -> Result<ProducersFieldValuesReader<'b>>
+    where
+        'a: 'b,
+    {
+        Ok(ProducersFieldValuesReader {
+            reader: BinaryReader::new_with_offset(self.values_data, self.values_offset),
+            count: self.values_count,
+        })
+    }
+}
+
+pub struct ProducersSectionReader<'a> {
+    reader: BinaryReader<'a>,
+    count: u32,
+}
+
+impl<'a> ProducersSectionReader<'a> {
+    /// Creates reader for the producers section.
+    ///
+    /// # Examples
+    /// ```
+    /// # let data: &[u8] = &[0x01, 0x08, 0x6c, 0x61, 0x6e, 0x67, 0x75, 0x61, 0x67, 0x65,
+    /// #     0x02, 0x03, 0x77, 0x61, 0x74, 0x01, 0x31, 0x01, 0x43, 0x03, 0x39, 0x2e, 0x30];
+    /// use wasmparser::{ProducersSectionReader, ProducersFieldValue, Result};
+    /// let mut reader = ProducersSectionReader::new(data, 0).expect("producers reader");
+    /// let field = reader.read().expect("producers field");
+    /// assert!(field.name == "language");
+    /// let mut values_reader = field.get_producer_field_values_reader().expect("values reader");
+    /// let value = values_reader.into_iter().collect::<Result<Vec<ProducersFieldValue>>>().expect("values");
+    /// assert!(value.len() == 2);
+    /// assert!(value[0].name == "wat" && value[0].version == "1");
+    /// assert!(value[1].name == "C" && value[1].version == "9.0");
+    /// ```
+    pub fn new(data: &'a [u8], offset: usize) -> Result<ProducersSectionReader<'a>> {
+        let mut reader = BinaryReader::new_with_offset(data, offset);
+        let count = reader.read_var_u32()?;
+        Ok(ProducersSectionReader { reader, count })
+    }
+
+    pub fn original_position(&self) -> usize {
+        self.reader.original_position()
+    }
+
+    pub fn get_count(&self) -> u32 {
+        self.count
+    }
+
+    pub fn read<'b>(&mut self) -> Result<ProducersField<'b>>
+    where
+        'a: 'b,
+    {
+        let name = self.reader.read_string()?;
+        let values_count = self.reader.read_var_u32()?;
+        let values_start = self.reader.position;
+        ProducersFieldValuesReader::skip(&mut self.reader, values_count)?;
+        let values_end = self.reader.position;
+        Ok(ProducersField {
+            name,
+            values_count,
+            values_data: &self.reader.buffer[values_start..values_end],
+            values_offset: self.reader.original_offset + values_start,
+        })
+    }
+}
+
+impl<'a> SectionReader for ProducersSectionReader<'a> {
+    type Item = ProducersField<'a>;
+    fn read(&mut self) -> Result<Self::Item> {
+        ProducersSectionReader::read(self)
+    }
+    fn eof(&self) -> bool {
+        self.reader.eof()
+    }
+    fn original_position(&self) -> usize {
+        ProducersSectionReader::original_position(self)
+    }
+    fn range(&self) -> Range {
+        self.reader.range()
+    }
+}
+
+impl<'a> SectionWithLimitedItems for ProducersSectionReader<'a> {
+    fn get_count(&self) -> u32 {
+        ProducersSectionReader::get_count(self)
+    }
+}
+
+impl<'a> IntoIterator for ProducersSectionReader<'a> {
+    type Item = Result<ProducersField<'a>>;
+    type IntoIter = SectionIteratorLimited<ProducersSectionReader<'a>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        SectionIteratorLimited::new(self)
+    }
+}