Merge #9128

9128: feat: expand procedural attribute macros r=jonas-schievink a=jonas-schievink

This adds experimental support for attribute macros. They can be enabled by setting `rust-analyzer.experimental.procAttrMacros` to `true`.

Known issues:
* Tokens aren't remapped, presumably because we edit the input syntax tree (this causes IDE features to not work inside items with attribute macros on them)
* Macro errors aren't reported correctly

Closes https://github.com/rust-analyzer/rust-analyzer/issues/8971
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/8964 / https://github.com/la10736/rstest/issues/120
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/2984
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/5412
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/6029
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/6687

https://github.com/rust-analyzer/rust-analyzer/issues/6740 is still not fixed – we now expand `#[proc_macro_hack]`, but fail to expand the resulting `proc_macro_call!()` macro.

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 15 insertions, 1 deletions

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index d3ef29db4..b43d61d0e 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -534,6 +534,18 @@ impl Module {
                                 Some(derive_name.clone()),
                             )
                         }
+                        MacroCallKind::Attr { ast_id, invoc_attr_index, attr_name, .. } => {
+                            let node = ast_id.to_node(db.upcast());
+                            let attr =
+                                node.attrs().nth((*invoc_attr_index) as usize).unwrap_or_else(
+                                    || panic!("cannot find attribute #{}", invoc_attr_index),
+                                );
+                            (
+                                ast_id.file_id,
+                                SyntaxNodePtr::from(AstPtr::new(&attr)),
+                                Some(attr_name.clone()),
+                            )
+                        }
                     };
                     sink.push(UnresolvedProcMacro {
                         file,
@@ -558,7 +570,9 @@ impl Module {
                             let node = ast_id.to_node(db.upcast());
                             (ast_id.file_id, SyntaxNodePtr::from(AstPtr::new(&node)))
                         }
-                        MacroCallKind::Derive { ast_id, .. } => {
+                        MacroCallKind::Derive { ast_id, .. }
+                        | MacroCallKind::Attr { ast_id, .. } => {
+                            // FIXME: point to the attribute instead, this creates very large diagnostics
                             let node = ast_id.to_node(db.upcast());
                             (ast_id.file_id, SyntaxNodePtr::from(AstPtr::new(&node)))
                         }