1pub mod extension_builder;
 2mod extension_manifest;
 3
 4use anyhow::{anyhow, bail, Context as _, Result};
 5use semantic_version::SemanticVersion;
 6
 7pub use crate::extension_manifest::*;
 8
 9pub fn parse_wasm_extension_version(
10    extension_id: &str,
11    wasm_bytes: &[u8],
12) -> Result<SemanticVersion> {
13    let mut version = None;
14
15    for part in wasmparser::Parser::new(0).parse_all(wasm_bytes) {
16        if let wasmparser::Payload::CustomSection(s) =
17            part.context("error parsing wasm extension")?
18        {
19            if s.name() == "zed:api-version" {
20                version = parse_wasm_extension_version_custom_section(s.data());
21                if version.is_none() {
22                    bail!(
23                        "extension {} has invalid zed:api-version section: {:?}",
24                        extension_id,
25                        s.data()
26                    );
27                }
28            }
29        }
30    }
31
32    // The reason we wait until we're done parsing all of the Wasm bytes to return the version
33    // is to work around a panic that can happen inside of Wasmtime when the bytes are invalid.
34    //
35    // By parsing the entirety of the Wasm bytes before we return, we're able to detect this problem
36    // earlier as an `Err` rather than as a panic.
37    version.ok_or_else(|| anyhow!("extension {} has no zed:api-version section", extension_id))
38}
39
40fn parse_wasm_extension_version_custom_section(data: &[u8]) -> Option<SemanticVersion> {
41    if data.len() == 6 {
42        Some(SemanticVersion::new(
43            u16::from_be_bytes([data[0], data[1]]) as _,
44            u16::from_be_bytes([data[2], data[3]]) as _,
45            u16::from_be_bytes([data[4], data[5]]) as _,
46        ))
47    } else {
48        None
49    }
50}