Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use std::fs;
use anyhow::{bail, Context};
use camino::Utf8PathBuf;
use crate::Result;
/// Responsible for looking up UDL and config paths
///
/// This uses a layered approach supporting multiple ways to find the paths.
/// The first added layer takes precedence.
#[derive(Default)]
pub struct BindgenPaths {
layers: Vec<Box<dyn BindgenPathsLayer>>,
}
impl BindgenPaths {
#[cfg(feature = "cargo-metadata")]
/// Add a layer that finds paths using `cargo metadata`
///
/// Requires the `cargo-metadata` feature.
pub fn add_cargo_metadata_layer(&mut self, no_deps: bool) -> Result<()> {
self.add_layer(
crate::cargo_metadata::CrateConfigSupplier::from_cargo_metadata_command(no_deps)?,
);
Ok(())
}
/// Add a layer that always uses the same path for config files
///
/// Used to implement the `--config` CLI flag.
pub fn add_config_override_layer(&mut self, path: Utf8PathBuf) {
self.add_layer(ConfigOverrideLayer { path })
}
/// Add a layer using a [BindgenPathsLayer]
///
/// This can be used to add custom path finding logic.
pub fn add_layer(&mut self, layer: impl BindgenPathsLayer + 'static) {
self.layers.push(Box::new(layer));
}
/// Get the config table for a crate
pub fn get_config(&self, crate_name: &str) -> Result<toml::value::Table> {
for layer in &self.layers {
if let Some(table) = layer.get_config(crate_name)? {
return Ok(table);
}
}
Ok(toml::value::Table::default())
}
/// Get the UDL path for a crate
pub fn get_udl_path(&self, crate_name: &str, udl_name: &str) -> Option<Utf8PathBuf> {
self.layers
.iter()
.find_map(|l| l.get_udl_path(crate_name, udl_name))
}
/// Get the UDL source for a crate
pub fn get_udl(&self, crate_name: &str, udl_name: &str) -> Result<String> {
match self.get_udl_path(crate_name, udl_name) {
Some(path) => Ok(fs::read_to_string(path)?),
None => bail!("UDL file {udl_name:?} not found for crate {crate_name:?}"),
}
}
}
/// Trait for finding UDL and config paths
pub trait BindgenPathsLayer {
/// Lookup and load the config TOML for a crate.
///
/// This is usually loaded from `[crate-root]/uniffi.toml`. However, layers are
/// free to obtain the TOML table for a crate however they want. For example:
/// * There could be a shared TOML file for all crates and this method could
/// return one of the child table values for the specified crate.
/// * The TOML could be hard-coded into source code and not loaded from a file at all.
/// * etc.
fn get_config(&self, _crate_name: &str) -> Result<Option<toml::value::Table>> {
Ok(None)
}
/// Lookup the a UDL file path.
///
/// This is usually the `[crate-root]/src/[udl_name].udl`
fn get_udl_path(&self, _crate_name: &str, _udl_name: &str) -> Option<Utf8PathBuf> {
None
}
}
struct ConfigOverrideLayer {
path: Utf8PathBuf,
}
impl BindgenPathsLayer for ConfigOverrideLayer {
fn get_config(&self, _crate_name: &str) -> Result<Option<toml::value::Table>> {
// ConfigOverrideLayer is used when an expected config override is expected to exist
// (eg, --config args), so the file not existing should be an error.
let contents = fs::read_to_string(&self.path)
.with_context(|| format!("read file: {:?}", self.path))?;
let toml = toml::de::from_str(&contents)
.with_context(|| format!("parse toml: {:?}", self.path))?;
Ok(Some(toml))
}
}