1/* Copyright 2018 Mozilla Foundation
2 *
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16use crate::{
17 BinaryReader, ExternalKind, FromReader, GlobalType, MemoryType, Result, SectionLimited,
18 TableType, TagType,
19};
20
21/// Represents a reference to a type definition in a WebAssembly module.
22#[derive(Debug, Clone, Copy, Eq, PartialEq)]
23pub enum TypeRef {
24 /// The type is a function.
25 ///
26 /// The value is an index into the type section.
27 Func(u32),
28 /// The type is a table.
29 Table(TableType),
30 /// The type is a memory.
31 Memory(MemoryType),
32 /// The type is a global.
33 Global(GlobalType),
34 /// The type is a tag.
35 ///
36 /// This variant is only used for the exception handling proposal.
37 ///
38 /// The value is an index in the types index space.
39 Tag(TagType),
40}
41
42/// Represents an import in a WebAssembly module.
43#[derive(Debug, Copy, Clone, Eq, PartialEq)]
44pub struct Import<'a> {
45 /// The module being imported from.
46 pub module: &'a str,
47 /// The name of the imported item.
48 pub name: &'a str,
49 /// The type of the imported item.
50 pub ty: TypeRef,
51}
52
53/// A reader for the import section of a WebAssembly module.
54pub type ImportSectionReader<'a> = SectionLimited<'a, Import<'a>>;
55
56impl<'a> FromReader<'a> for Import<'a> {
57 fn from_reader(reader: &mut BinaryReader<'a>) -> Result<Self> {
58 Ok(Import {
59 module: reader.read()?,
60 name: reader.read()?,
61 ty: reader.read()?,
62 })
63 }
64}
65
66impl<'a> FromReader<'a> for TypeRef {
67 fn from_reader(reader: &mut BinaryReader<'a>) -> Result<Self> {
68 Ok(match reader.read()? {
69 ExternalKind::Func => TypeRef::Func(reader.read_var_u32()?),
70 ExternalKind::Table => TypeRef::Table(reader.read()?),
71 ExternalKind::Memory => TypeRef::Memory(reader.read()?),
72 ExternalKind::Global => TypeRef::Global(reader.read()?),
73 ExternalKind::Tag => TypeRef::Tag(reader.read()?),
74 })
75 }
76}
77