1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
use std::borrow::Cow;
use crate::{CustomSection, Encode, Section, SectionId};
/// An encoder for the [producers custom
/// section](https://github.com/WebAssembly/tool-conventions/blob/main/ProducersSection.md).
///
/// This section is a non-standard convention that is supported by many toolchains.
///
/// # Example
///
/// ```
/// use wasm_encoder::{ProducersSection, ProducersField, Module};
///
/// // Create a new producers section.
/// let mut field = ProducersField::new();
/// field.value("clang", "14.0.4");
/// field.value("rustc", "1.66.1 (90743e729 2023-01-10)");
/// let mut producers = ProducersSection::new();
/// producers.field("processed-by", &field);
///
/// // Add the producers section to a new Wasm module and get the encoded bytes.
/// let mut module = Module::new();
/// module.section(&producers);
/// let wasm_bytes = module.finish();
/// ```
#[derive(Clone, Debug)]
pub struct ProducersSection {
bytes: Vec<u8>,
num_fields: u32,
}
impl ProducersSection {
/// Construct an empty encoder for the producers custom section.
pub fn new() -> Self {
Self::default()
}
/// Add a field to the section. The spec recommends names for this section
/// are "language", "processed-by", and "sdk". Each field in section must
/// have a unique name.
pub fn field(&mut self, name: &str, values: &ProducersField) -> &mut Self {
name.encode(&mut self.bytes);
values.encode(&mut self.bytes);
self.num_fields += 1;
self
}
}
impl Default for ProducersSection {
fn default() -> Self {
Self {
bytes: Vec::new(),
num_fields: 0,
}
}
}
impl Encode for ProducersSection {
fn encode(&self, sink: &mut Vec<u8>) {
let mut data = Vec::new();
self.num_fields.encode(&mut data);
data.extend(&self.bytes);
CustomSection {
name: "producers".into(),
data: Cow::Borrowed(&data),
}
.encode(sink);
}
}
impl Section for ProducersSection {
fn id(&self) -> u8 {
SectionId::Custom.into()
}
}
/// The value of a field in the producers custom section
#[derive(Clone, Debug)]
pub struct ProducersField {
bytes: Vec<u8>,
num_values: u32,
}
impl ProducersField {
/// Construct an empty encoder for a producers field value
pub fn new() -> Self {
ProducersField::default()
}
/// Add a value to the field encoder. Each value in a field must have a
/// unique name. If there is no sensible value for `version`, use the
/// empty string.
pub fn value(&mut self, name: &str, version: &str) -> &mut Self {
name.encode(&mut self.bytes);
version.encode(&mut self.bytes);
self.num_values += 1;
self
}
}
impl Default for ProducersField {
fn default() -> Self {
Self {
bytes: Vec::new(),
num_values: 0,
}
}
}
impl Encode for ProducersField {
fn encode(&self, sink: &mut Vec<u8>) {
self.num_values.encode(sink);
sink.extend(&self.bytes);
}
}
#[cfg(test)]
mod test {
#[test]
fn roundtrip_example() {
use crate::{Module, ProducersField, ProducersSection};
use wasmparser::{Parser, Payload, ProducersSectionReader};
// Create a new producers section.
let mut field = ProducersField::new();
field.value("clang", "14.0.4");
field.value("rustc", "1.66.1");
let mut producers = ProducersSection::new();
producers.field("processed-by", &field);
// Add the producers section to a new Wasm module and get the encoded bytes.
let mut module = Module::new();
module.section(&producers);
let wasm_bytes = module.finish();
let mut parser = Parser::new(0).parse_all(&wasm_bytes);
let payload = parser
.next()
.expect("parser is not empty")
.expect("element is a payload");
match payload {
Payload::Version { .. } => {}
_ => panic!(""),
}
let payload = parser
.next()
.expect("parser is not empty")
.expect("element is a payload");
match payload {
Payload::CustomSection(c) => {
assert_eq!(c.name(), "producers");
let mut section = ProducersSectionReader::new(c.data(), c.data_offset())
.expect("readable as a producers section")
.into_iter();
let field = section
.next()
.expect("section has an element")
.expect("element is a producers field");
assert_eq!(field.name, "processed-by");
let mut values = field.values.into_iter();
let value = values
.next()
.expect("values has an element")
.expect("element is a producers field value");
assert_eq!(value.name, "clang");
assert_eq!(value.version, "14.0.4");
let value = values
.next()
.expect("values has another element")
.expect("element is a producers field value");
assert_eq!(value.name, "rustc");
assert_eq!(value.version, "1.66.1");
}
_ => panic!("unexpected payload"),
}
}
}
|
