bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-expand/src/proc_macro.rs')
-rw-r--r--crates/hir-expand/src/proc_macro.rs70
1 files changed, 70 insertions, 0 deletions
diff --git a/crates/hir-expand/src/proc_macro.rs b/crates/hir-expand/src/proc_macro.rs
new file mode 100644
index 0000000000..df6c38761c
--- /dev/null
+++ b/crates/hir-expand/src/proc_macro.rs
@@ -0,0 +1,70 @@
+//! Proc Macro Expander stub
+
+use base_db::{CrateId, ProcMacroExpansionError, ProcMacroId, ProcMacroKind};
+
+use crate::{db::AstDatabase, ExpandError, ExpandResult};
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+pub struct ProcMacroExpander {
+ krate: CrateId,
+ proc_macro_id: Option<ProcMacroId>,
+}
+
+impl ProcMacroExpander {
+ pub fn new(krate: CrateId, proc_macro_id: ProcMacroId) -> Self {
+ Self { krate, proc_macro_id: Some(proc_macro_id) }
+ }
+
+ pub fn dummy(krate: CrateId) -> Self {
+ // FIXME: Should store the name for better errors
+ Self { krate, proc_macro_id: None }
+ }
+
+ pub fn is_dummy(&self) -> bool {
+ self.proc_macro_id.is_none()
+ }
+
+ pub fn expand(
+ self,
+ db: &dyn AstDatabase,
+ calling_crate: CrateId,
+ tt: &tt::Subtree,
+ attr_arg: Option<&tt::Subtree>,
+ ) -> ExpandResult<tt::Subtree> {
+ match self.proc_macro_id {
+ Some(id) => {
+ let krate_graph = db.crate_graph();
+ let proc_macro = match krate_graph[self.krate].proc_macro.get(id.0 as usize) {
+ Some(proc_macro) => proc_macro,
+ None => {
+ return ExpandResult::only_err(ExpandError::Other(
+ "No proc-macro found.".into(),
+ ))
+ }
+ };
+
+ // Proc macros have access to the environment variables of the invoking crate.
+ let env = &krate_graph[calling_crate].env;
+ match proc_macro.expander.expand(tt, attr_arg, env) {
+ Ok(t) => ExpandResult::ok(t),
+ Err(err) => match err {
+ // Don't discard the item in case something unexpected happened while expanding attributes
+ ProcMacroExpansionError::System(text)
+ if proc_macro.kind == ProcMacroKind::Attr =>
+ {
+ ExpandResult {
+ value: tt.clone(),
+ err: Some(ExpandError::Other(text.into())),
+ }
+ }
+ ProcMacroExpansionError::System(text)
+ | ProcMacroExpansionError::Panic(text) => {
+ ExpandResult::only_err(ExpandError::Other(text.into()))
+ }
+ },
+ }
+ }
+ None => ExpandResult::only_err(ExpandError::UnresolvedProcMacro),
+ }
+ }
+}