wasm/validation/
custom_section.rs

1use crate::{
2    core::reader::{
3        section_header::{SectionHeader, SectionTy},
4        WasmReader,
5    },
6    ValidationError,
7};
8
9#[derive(Debug, Clone)]
10pub struct CustomSection<'wasm> {
11    pub name: &'wasm str,
12    pub contents: &'wasm [u8],
13}
14
15impl<'wasm> CustomSection<'wasm> {
16    pub(crate) fn read_and_validate(
17        wasm: &mut WasmReader<'wasm>,
18        header: SectionHeader,
19    ) -> Result<CustomSection<'wasm>, ValidationError> {
20        assert_eq!(header.ty, SectionTy::Custom);
21
22        // customsec ::= section_0(custom)
23        // custom ::= name byte*
24        // name ::= b*:vec(byte) => name (if utf8(name) = b*)
25        // vec(B) ::= n:u32 (x:B)^n => x^n
26        let name = wasm.read_name()?;
27
28        let section_start = wasm.pc;
29        let section_end = header
30            .contents
31            .from()
32            .checked_add(header.contents.len())
33            .ok_or(ValidationError::InvalidCustomSectionLength)?;
34
35        let contents = wasm
36            .full_wasm_binary
37            .get(section_start..section_end)
38            .ok_or(ValidationError::InvalidCustomSectionLength)?;
39
40        let section_len = section_end
41            .checked_sub(section_start)
42            .expect("section start <= section end always");
43
44        wasm.skip(section_len)?;
45
46        Ok(CustomSection { name, contents })
47    }
48}
wasm/validation/custom_section.rs

wasm/validation/
custom_section.rs
