1 files changed, 102 insertions, 0 deletions
diff --git a/third_party/rust/wasmparser/src/readers/component/names.rs b/third_party/rust/wasmparser/src/readers/component/names.rs
new file mode 100644
index 0000000000..19de2752d0
--- /dev/null
+++ b/third_party/rust/wasmparser/src/readers/component/names.rs
@@ -0,0 +1,102 @@
+use crate::{BinaryReader, BinaryReaderError, NameMap, Result, Subsection, Subsections};
+use std::ops::Range;
+
+/// Type used to iterate and parse the contents of the `component-name` custom
+/// section in compnents, similar to the `name` section of core modules.
+pub type ComponentNameSectionReader<'a> = Subsections<'a, ComponentName<'a>>;
+
+/// Represents a name read from the names custom section.
+#[derive(Clone)]
+#[allow(missing_docs)]
+pub enum ComponentName<'a> {
+    Component {
+        name: &'a str,
+        name_range: Range<usize>,
+    },
+    CoreFuncs(NameMap<'a>),
+    CoreGlobals(NameMap<'a>),
+    CoreMemories(NameMap<'a>),
+    CoreTables(NameMap<'a>),
+    CoreModules(NameMap<'a>),
+    CoreInstances(NameMap<'a>),
+    CoreTypes(NameMap<'a>),
+    Types(NameMap<'a>),
+    Instances(NameMap<'a>),
+    Components(NameMap<'a>),
+    Funcs(NameMap<'a>),
+    Values(NameMap<'a>),
+
+    /// An unknown [name subsection](https://webassembly.github.io/spec/core/appendix/custom.html#subsections).
+    Unknown {
+        /// The identifier for this subsection.
+        ty: u8,
+        /// The contents of this subsection.
+        data: &'a [u8],
+        /// The range of bytes, relative to the start of the original data
+        /// stream, that the contents of this subsection reside in.
+        range: Range<usize>,
+    },
+}
+
+impl<'a> Subsection<'a> for ComponentName<'a> {
+    fn from_reader(id: u8, mut reader: BinaryReader<'a>) -> Result<Self> {
+        let data = reader.remaining_buffer();
+        let offset = reader.original_position();
+        Ok(match id {
+            0 => {
+                let name = reader.read_string()?;
+                if !reader.eof() {
+                    return Err(BinaryReaderError::new(
+                        "trailing data at the end of a name",
+                        reader.original_position(),
+                    ));
+                }
+                ComponentName::Component {
+                    name,
+                    name_range: offset..offset + reader.position,
+                }
+            }
+            1 => {
+                let ctor: fn(NameMap<'a>) -> ComponentName<'a> = match reader.read_u8()? {
+                    0x00 => match reader.read_u8()? {
+                        0x00 => ComponentName::CoreFuncs,
+                        0x01 => ComponentName::CoreTables,
+                        0x02 => ComponentName::CoreMemories,
+                        0x03 => ComponentName::CoreGlobals,
+                        0x10 => ComponentName::CoreTypes,
+                        0x11 => ComponentName::CoreModules,
+                        0x12 => ComponentName::CoreInstances,
+                        _ => {
+                            return Ok(ComponentName::Unknown {
+                                ty: 1,
+                                data,
+                                range: offset..offset + data.len(),
+                            });
+                        }
+                    },
+                    0x01 => ComponentName::Funcs,
+                    0x02 => ComponentName::Values,
+                    0x03 => ComponentName::Types,
+                    0x04 => ComponentName::Components,
+                    0x05 => ComponentName::Instances,
+                    _ => {
+                        return Ok(ComponentName::Unknown {
+                            ty: 1,
+                            data,
+                            range: offset..offset + data.len(),
+                        });
+                    }
+                };
+                ctor(NameMap::new(
+                    reader.remaining_buffer(),
+                    reader.original_position(),
+                )?)
+            }
+            ty => ComponentName::Unknown {
+                ty,
+                data,
+                range: offset..offset + data.len(),
+            },
+        })
+    }
+}