bendns' repos / helix
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'helix-syntax/src/tree_sitter/grammar.rs')
-rw-r--r--helix-syntax/src/tree_sitter/grammar.rs107
1 files changed, 107 insertions, 0 deletions
diff --git a/helix-syntax/src/tree_sitter/grammar.rs b/helix-syntax/src/tree_sitter/grammar.rs
new file mode 100644
index 00000000..fe164e75
--- /dev/null
+++ b/helix-syntax/src/tree_sitter/grammar.rs
@@ -0,0 +1,107 @@
+use std::fmt;
+use std::path::{Path, PathBuf};
+use std::ptr::NonNull;
+
+use libloading::{Library, Symbol};
+
+/// supported TS versions, WARNING: update when updating vendored c sources
+pub const MIN_COMPATIBLE_ABI_VERSION: u32 = 13;
+pub const ABI_VERSION: u32 = 14;
+
+// opaque pointer
+enum GrammarData {}
+
+#[repr(transparent)]
+#[derive(Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Grammar {
+ ptr: NonNull<GrammarData>,
+}
+
+unsafe impl Send for Grammar {}
+unsafe impl Sync for Grammar {}
+
+impl std::fmt::Debug for Grammar {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ f.debug_struct("Grammar").finish_non_exhaustive()
+ }
+}
+
+impl Grammar {
+ /// Loads a shared library containg a tree sitter grammar with name `name`
+ // from `library_path`.
+ ///
+ /// # Safety
+ ///
+ /// `library_path` must be a valid tree sitter grammar
+ pub unsafe fn new(name: &str, library_path: &Path) -> Result<Grammar, Error> {
+ let library = unsafe {
+ Library::new(library_path).map_err(|err| Error::DlOpen {
+ err,
+ path: library_path.to_owned(),
+ })?
+ };
+ let language_fn_name = format!("tree_sitter_{}", name.replace('-', "_"));
+ let grammar = unsafe {
+ let language_fn: Symbol<unsafe extern "C" fn() -> NonNull<GrammarData>> = library
+ .get(language_fn_name.as_bytes())
+ .map_err(|err| Error::DlSym {
+ err,
+ symbol: name.to_owned(),
+ })?;
+ Grammar { ptr: language_fn() }
+ };
+ let version = grammar.version();
+ if (MIN_COMPATIBLE_ABI_VERSION..=ABI_VERSION).contains(&version) {
+ std::mem::forget(library);
+ Ok(grammar)
+ } else {
+ Err(Error::IncompatibleVersion { version })
+ }
+ }
+ pub fn version(self) -> u32 {
+ unsafe { ts_language_version(self) }
+ }
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+ #[error("Error opening dynamic library {path:?}")]
+ DlOpen {
+ #[source]
+ err: libloading::Error,
+ path: PathBuf,
+ },
+ #[error("Failed to load symbol {symbol}")]
+ DlSym {
+ #[source]
+ err: libloading::Error,
+ symbol: String,
+ },
+ #[error("Tried to load grammar with incompatible ABI {version}.")]
+ IncompatibleVersion { version: u32 },
+}
+
+/// An error that occurred when trying to assign an incompatible [`Grammar`] to
+/// a [`Parser`].
+#[derive(Debug, PartialEq, Eq)]
+pub struct IncompatibleGrammarError {
+ version: u32,
+}
+
+impl fmt::Display for IncompatibleGrammarError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(
+ f,
+ "Tried to load grammar with incompatible ABI {}.",
+ self.version,
+ )
+ }
+}
+impl std::error::Error for IncompatibleGrammarError {}
+
+extern "C" {
+ /// Get the ABI version number for this language. This version number
+ /// is used to ensure that languages were generated by a compatible version of
+ /// Tree-sitter. See also [`ts_parser_set_language`].
+ pub fn ts_language_version(grammar: Grammar) -> u32;
+}