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Don't discard attributed items when a proc-macro unexpectedly fails to expand

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This commit is contained in:
Lukas Wirth 2021-10-27 14:35:58 +02:00
parent 54e6583f53
commit 98cff6572d
2 changed files with 23 additions and 13 deletions
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34
crates/hir_expand/src/proc_macro.rs
View File

@ -1,9 +1,10 @@
//! Proc Macro Expander stub
use crate::db::AstDatabase;
use base_db::{CrateId, ProcMacroExpansionError, ProcMacroId};
use base_db::{CrateId, ProcMacroExpansionError, ProcMacroId, ProcMacroKind};
use mbe::ExpandResult;
use crate::db::AstDatabase;
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub struct ProcMacroExpander {
krate: CrateId,
@ -36,20 +37,29 @@ pub fn expand(
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::str_err("No derive macro found.".to_string()),
None => return ExpandResult::str_err("No proc-macro found.".to_string()),
};
// Proc macros have access to the environment variables of the invoking crate.
let env = &krate_graph[calling_crate].env;
proc_macro
.expander
.expand(tt, attr_arg, env)
.map_err(|err| match err {
ProcMacroExpansionError::Panic(text) => mbe::ExpandError::Other(text),
ProcMacroExpansionError::System(text) => mbe::ExpandError::Other(text),
})
.into()
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(mbe::ExpandError::Other(text)),
}
}
ProcMacroExpansionError::System(text)
| ProcMacroExpansionError::Panic(text) => {
ExpandResult::only_err(mbe::ExpandError::Other(text))
}
},
}
}
None => ExpandResult::only_err(mbe::ExpandError::UnresolvedProcMacro),
}

2
crates/proc_macro_api/src/lib.rs
View File

@ -167,7 +167,7 @@ pub fn expand(
let request = msg::Request::ExpandMacro(task);
let response = self.process.lock().unwrap_or_else(|e| e.into_inner()).send_task(request)?;
match response {
msg::Response::ExpandMacro(it) => Ok(it.map(|it| it.to_subtree())),
msg::Response::ExpandMacro(it) => Ok(it.map(FlatTree::to_subtree)),
msg::Response::ListMacros { .. } => {
Err(ServerError { message: "unexpected response".to_string(), io: None })
}