From 2aa4a82499d4becd2284cdb482213d541b8804dd Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 28 Apr 2024 16:29:10 +0200
Subject: Adding upstream version 86.0.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../rust/wasmparser/src/readers/data_section.rs    | 152 +++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 third_party/rust/wasmparser/src/readers/data_section.rs

(limited to 'third_party/rust/wasmparser/src/readers/data_section.rs')

diff --git a/third_party/rust/wasmparser/src/readers/data_section.rs b/third_party/rust/wasmparser/src/readers/data_section.rs
new file mode 100644
index 0000000000..b9675e2de8
--- /dev/null
+++ b/third_party/rust/wasmparser/src/readers/data_section.rs
@@ -0,0 +1,152 @@
+/* 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, BinaryReaderError, InitExpr, Range, Result, SectionIteratorLimited,
+    SectionReader, SectionWithLimitedItems,
+};
+
+#[derive(Debug, Copy, Clone)]
+pub struct Data<'a> {
+    pub kind: DataKind<'a>,
+    pub data: &'a [u8],
+}
+
+#[derive(Debug, Copy, Clone)]
+pub enum DataKind<'a> {
+    Passive,
+    Active {
+        memory_index: u32,
+        init_expr: InitExpr<'a>,
+    },
+}
+
+#[derive(Clone)]
+pub struct DataSectionReader<'a> {
+    reader: BinaryReader<'a>,
+    count: u32,
+}
+
+impl<'a> DataSectionReader<'a> {
+    pub fn new(data: &'a [u8], offset: usize) -> Result<DataSectionReader<'a>> {
+        let mut reader = BinaryReader::new_with_offset(data, offset);
+        let count = reader.read_var_u32()?;
+        Ok(DataSectionReader { reader, count })
+    }
+
+    pub fn original_position(&self) -> usize {
+        self.reader.original_position()
+    }
+
+    pub fn get_count(&self) -> u32 {
+        self.count
+    }
+
+    fn verify_data_end(&self, end: usize) -> Result<()> {
+        if self.reader.buffer.len() < end {
+            return Err(BinaryReaderError::new(
+                "Data segment extends past end of the data section",
+                self.reader.original_offset + self.reader.buffer.len(),
+            ));
+        }
+        Ok(())
+    }
+
+    /// Reads content of the data section.
+    ///
+    /// # Examples
+    /// ```
+    /// use wasmparser::{DataSectionReader, DataKind};
+    /// # let data: &[u8] = &[
+    /// #     0x01, 0x00, 0x41, 0x80, 0x08, 0x0b, 0x04, 0x00, 0x00, 0x00, 0x00];
+    /// let mut data_reader = DataSectionReader::new(data, 0).unwrap();
+    /// for _ in 0..data_reader.get_count() {
+    ///     let data = data_reader.read().expect("data");
+    ///     println!("Data: {:?}", data);
+    ///     if let DataKind::Active { init_expr, .. } = data.kind {
+    ///         let mut init_expr_reader = init_expr.get_binary_reader();
+    ///         let op = init_expr_reader.read_operator().expect("op");
+    ///         println!("Init const: {:?}", op);
+    ///     }
+    /// }
+    /// ```
+    pub fn read<'b>(&mut self) -> Result<Data<'b>>
+    where
+        'a: 'b,
+    {
+        let flags = self.reader.read_var_u32()?;
+        let kind = if flags == 1 {
+            DataKind::Passive
+        } else {
+            let memory_index = match flags {
+                0 => 0,
+                2 => self.reader.read_var_u32()?,
+                _ => {
+                    return Err(BinaryReaderError::new(
+                        "invalid flags byte in data segment",
+                        self.reader.original_position() - 1,
+                    ));
+                }
+            };
+            let init_expr = {
+                let expr_offset = self.reader.position;
+                self.reader.skip_init_expr()?;
+                let data = &self.reader.buffer[expr_offset..self.reader.position];
+                InitExpr::new(data, self.reader.original_offset + expr_offset)
+            };
+            DataKind::Active {
+                memory_index,
+                init_expr,
+            }
+        };
+        let data_len = self.reader.read_var_u32()? as usize;
+        let data_end = self.reader.position + data_len;
+        self.verify_data_end(data_end)?;
+        let data = &self.reader.buffer[self.reader.position..data_end];
+        self.reader.skip_to(data_end);
+        Ok(Data { kind, data })
+    }
+}
+
+impl<'a> SectionReader for DataSectionReader<'a> {
+    type Item = Data<'a>;
+    fn read(&mut self) -> Result<Self::Item> {
+        DataSectionReader::read(self)
+    }
+    fn eof(&self) -> bool {
+        self.reader.eof()
+    }
+    fn original_position(&self) -> usize {
+        DataSectionReader::original_position(self)
+    }
+    fn range(&self) -> Range {
+        self.reader.range()
+    }
+}
+
+impl<'a> SectionWithLimitedItems for DataSectionReader<'a> {
+    fn get_count(&self) -> u32 {
+        DataSectionReader::get_count(self)
+    }
+}
+
+impl<'a> IntoIterator for DataSectionReader<'a> {
+    type Item = Result<Data<'a>>;
+    type IntoIter = SectionIteratorLimited<DataSectionReader<'a>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        SectionIteratorLimited::new(self)
+    }
+}
-- 
cgit v1.2.3