Auto merge of #16088 - Veykril:proc-macro-srv-2, r=Veykril

feat: Implement a rust-analyzer span backed proc-macro server mode

This implements the basic span APIs. Basically anything that doesn't require talking back to the client for information access.

This also commits our syntax fixup marker to use an `ErasedAstFileId` of `!0-1` aka `0xffff_fffe`, instead of using a dummy FileId as a marker, as we need that for the `SourceFile` API to be implementable. The reason as to why the server needs to know about this at all is to prevent it from creating invalid fixup spans which could make r-a panic.

.github/workflows/ci.yaml

@@ -38,7 +38,6 @@ jobs:
               - 'crates/proc-macro-api/**'
               - 'crates/proc-macro-srv/**'
               - 'crates/proc-macro-srv-cli/**'
-              - 'crates/proc-macro-test/**'
 
   rust:
     needs: changes

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 members = ["xtask/", "lib/*", "crates/*"]
-exclude = ["crates/proc-macro-test/imp"]
+exclude = ["crates/proc-macro-srv/proc-macro-test/"]
 resolver = "2"
 
 [workspace.package]
@@ -81,7 +81,6 @@ vfs = { path = "./crates/vfs", version = "0.0.0" }
 rustc-dependencies = { path = "./crates/rustc-dependencies", version = "0.0.0" }
 
 # local crates that aren't published to crates.io. These should not have versions.
-proc-macro-test = { path = "./crates/proc-macro-test" }
 sourcegen = { path = "./crates/sourcegen" }
 test-fixture = { path = "./crates/test-fixture" }
 test-utils = { path = "./crates/test-utils" }

crates/hir-expand/src/builtin_fn_macro.rs

@@ -108,6 +108,7 @@ register_builtin! {
     (format_args, FormatArgs) => format_args_expand,
     (const_format_args, ConstFormatArgs) => format_args_expand,
     (format_args_nl, FormatArgsNl) => format_args_nl_expand,
+    (quote, Quote) => quote_expand,
 
     EAGER:
     (compile_error, CompileError) => compile_error_expand,
@@ -770,3 +771,15 @@ fn option_env_expand(
 
     ExpandResult::ok(expanded)
 }
+
+fn quote_expand(
+    _db: &dyn ExpandDatabase,
+    _arg_id: MacroCallId,
+    _tt: &tt::Subtree,
+    span: Span,
+) -> ExpandResult<tt::Subtree> {
+    ExpandResult::new(
+        tt::Subtree::empty(tt::DelimSpan { open: span, close: span }),
+        ExpandError::other("quote! is not implemented"),
+    )
+}

crates/hir-expand/src/fixup.rs

@@ -1,10 +1,9 @@
 //! To make attribute macros work reliably when typing, we need to take care to
 //! fix up syntax errors in the code we're passing to them.
 
-use la_arena::RawIdx;
 use rustc_hash::{FxHashMap, FxHashSet};
 use smallvec::SmallVec;
-use span::{ErasedFileAstId, FileId, Span, SpanAnchor, SpanData};
+use span::{ErasedFileAstId, Span, SpanAnchor, SpanData, FIXUP_ERASED_FILE_AST_ID_MARKER};
 use stdx::never;
 use syntax::{
     ast::{self, AstNode, HasLoopBody},
@@ -39,13 +38,11 @@ impl SyntaxFixupUndoInfo {
     pub(crate) const NONE: Self = SyntaxFixupUndoInfo { original: None };
 }
 
-// censoring -> just don't convert the node
-// replacement -> censor + append
-// append -> insert a fake node, here we need to assemble some dummy span that we can figure out how
-// to remove later
-const FIXUP_DUMMY_FILE: FileId = FileId::from_raw(FileId::MAX_FILE_ID);
-const FIXUP_DUMMY_AST_ID: ErasedFileAstId = ErasedFileAstId::from_raw(RawIdx::from_u32(!0));
+// We mark spans with `FIXUP_DUMMY_AST_ID` to indicate that they are fake.
+const FIXUP_DUMMY_AST_ID: ErasedFileAstId = FIXUP_ERASED_FILE_AST_ID_MARKER;
 const FIXUP_DUMMY_RANGE: TextRange = TextRange::empty(TextSize::new(0));
+// If the fake span has this range end, that means that the range start is an index into the
+// `original` list in `SyntaxFixupUndoInfo`.
 const FIXUP_DUMMY_RANGE_END: TextSize = TextSize::new(!0);
 
 pub(crate) fn fixup_syntax(
@@ -58,13 +55,13 @@ pub(crate) fn fixup_syntax(
     let mut preorder = node.preorder();
     let mut original = Vec::new();
     let dummy_range = FIXUP_DUMMY_RANGE;
-    // we use a file id of `FileId(!0)` to signal a fake node, and the text range's start offset as
-    // the index into the replacement vec but only if the end points to !0
-    let dummy_anchor = SpanAnchor { file_id: FIXUP_DUMMY_FILE, ast_id: FIXUP_DUMMY_AST_ID };
-    let fake_span = |range| SpanData {
-        range: dummy_range,
-        anchor: dummy_anchor,
-        ctx: span_map.span_for_range(range).ctx,
+    let fake_span = |range| {
+        let span = span_map.span_for_range(range);
+        SpanData {
+            range: dummy_range,
+            anchor: SpanAnchor { ast_id: FIXUP_DUMMY_AST_ID, ..span.anchor },
+            ctx: span.ctx,
+        }
     };
     while let Some(event) = preorder.next() {
         let syntax::WalkEvent::Enter(node) = event else { continue };
@@ -76,12 +73,13 @@ pub(crate) fn fixup_syntax(
             let original_tree = mbe::syntax_node_to_token_tree(&node, span_map, call_site);
             let idx = original.len() as u32;
             original.push(original_tree);
+            let span = span_map.span_for_range(node_range);
             let replacement = Leaf::Ident(Ident {
                 text: "__ra_fixup".into(),
                 span: SpanData {
                     range: TextRange::new(TextSize::new(idx), FIXUP_DUMMY_RANGE_END),
-                    anchor: dummy_anchor,
-                    ctx: span_map.span_for_range(node_range).ctx,
+                    anchor: SpanAnchor { ast_id: FIXUP_DUMMY_AST_ID, ..span.anchor },
+                    ctx: span.ctx,
                 },
             });
             append.insert(node.clone().into(), vec![replacement]);
@@ -304,8 +302,8 @@ pub(crate) fn reverse_fixups(tt: &mut Subtree, undo_info: &SyntaxFixupUndoInfo)
     let undo_info = &**undo_info;
     #[allow(deprecated)]
     if never!(
-        tt.delimiter.close.anchor.file_id == FIXUP_DUMMY_FILE
-            || tt.delimiter.open.anchor.file_id == FIXUP_DUMMY_FILE
+        tt.delimiter.close.anchor.ast_id == FIXUP_DUMMY_AST_ID
+            || tt.delimiter.open.anchor.ast_id == FIXUP_DUMMY_AST_ID
     ) {
         tt.delimiter.close = SpanData::DUMMY;
         tt.delimiter.open = SpanData::DUMMY;
@@ -321,16 +319,16 @@ fn reverse_fixups_(tt: &mut Subtree, undo_info: &[Subtree]) {
         .filter(|tt| match tt {
             tt::TokenTree::Leaf(leaf) => {
                 let span = leaf.span();
-                let is_real_leaf = span.anchor.file_id != FIXUP_DUMMY_FILE;
+                let is_real_leaf = span.anchor.ast_id != FIXUP_DUMMY_AST_ID;
                 let is_replaced_node = span.range.end() == FIXUP_DUMMY_RANGE_END;
                 is_real_leaf || is_replaced_node
             }
             tt::TokenTree::Subtree(_) => true,
         })
         .flat_map(|tt| match tt {
             tt::TokenTree::Subtree(mut tt) => {
-                if tt.delimiter.close.anchor.file_id == FIXUP_DUMMY_FILE
-                    || tt.delimiter.open.anchor.file_id == FIXUP_DUMMY_FILE
+                if tt.delimiter.close.anchor.ast_id == FIXUP_DUMMY_AST_ID
+                    || tt.delimiter.open.anchor.ast_id == FIXUP_DUMMY_AST_ID
                 {
                     // Even though fixup never creates subtrees with fixup spans, the old proc-macro server
                     // might copy them if the proc-macro asks for it, so we need to filter those out
@@ -341,7 +339,7 @@ fn reverse_fixups_(tt: &mut Subtree, undo_info: &[Subtree]) {
                 SmallVec::from_const([tt.into()])
             }
             tt::TokenTree::Leaf(leaf) => {
-                if leaf.span().anchor.file_id == FIXUP_DUMMY_FILE {
+                if leaf.span().anchor.ast_id == FIXUP_DUMMY_AST_ID {
                     // we have a fake node here, we need to replace it again with the original
                     let original = undo_info[u32::from(leaf.span().range.start()) as usize].clone();
                     if original.delimiter.kind == tt::DelimiterKind::Invisible {

crates/hir-expand/src/name.rs

@@ -388,6 +388,7 @@ pub mod known {
         log_syntax,
         module_path,
         option_env,
+        quote,
         std_panic,
         stringify,
         trace_macros,

crates/hir/src/source_analyzer.rs

@@ -1162,9 +1162,40 @@ fn resolve_hir_path_qualifier(
     resolver: &Resolver,
     path: &Path,
 ) -> Option<PathResolution> {
-    resolver
-        .resolve_path_in_type_ns_fully(db.upcast(), &path)
-        .map(|ty| match ty {
+    (|| {
+        let (ty, unresolved) = match path.type_anchor() {
+            Some(type_ref) => {
+                let (_, res) =
+                    TyLoweringContext::new_maybe_unowned(db, resolver, resolver.type_owner())
+                        .lower_ty_ext(type_ref);
+                res.map(|ty_ns| (ty_ns, path.segments().first()))
+            }
+            None => {
+                let (ty, remaining_idx, _) = resolver.resolve_path_in_type_ns(db.upcast(), path)?;
+                match remaining_idx {
+                    Some(remaining_idx) => {
+                        if remaining_idx + 1 == path.segments().len() {
+                            Some((ty, path.segments().last()))
+                        } else {
+                            None
+                        }
+                    }
+                    None => Some((ty, None)),
+                }
+            }
+        }?;
+
+        // If we are in a TypeNs for a Trait, and we have an unresolved name, try to resolve it as a type
+        // within the trait's associated types.
+        if let (Some(unresolved), &TypeNs::TraitId(trait_id)) = (&unresolved, &ty) {
+            if let Some(type_alias_id) =
+                db.trait_data(trait_id).associated_type_by_name(unresolved.name)
+            {
+                return Some(PathResolution::Def(ModuleDefId::from(type_alias_id).into()));
+            }
+        }
+
+        let res = match ty {
             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
             TypeNs::GenericParam(id) => PathResolution::TypeParam(id.into()),
             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
@@ -1175,11 +1206,28 @@ fn resolve_hir_path_qualifier(
             TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
             TypeNs::TraitAliasId(it) => PathResolution::Def(TraitAlias::from(it).into()),
-        })
-        .or_else(|| {
-            resolver
-                .resolve_module_path_in_items(db.upcast(), path.mod_path()?)
-                .take_types()
-                .map(|it| PathResolution::Def(it.into()))
-        })
+        };
+        match unresolved {
+            Some(unresolved) => resolver
+                .generic_def()
+                .and_then(|def| {
+                    hir_ty::associated_type_shorthand_candidates(
+                        db,
+                        def,
+                        res.in_type_ns()?,
+                        |name, id| (name == unresolved.name).then_some(id),
+                    )
+                })
+                .map(TypeAlias::from)
+                .map(Into::into)
+                .map(PathResolution::Def),
+            None => Some(res),
+        }
+    })()
+    .or_else(|| {
+        resolver
+            .resolve_module_path_in_items(db.upcast(), path.mod_path()?)
+            .take_types()
+            .map(|it| PathResolution::Def(it.into()))
+    })
 }

crates/proc-macro-api/src/lib.rs

@@ -20,7 +20,10 @@ use triomphe::Arc;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    msg::{ExpandMacro, ExpnGlobals, FlatTree, PanicMessage, HAS_GLOBAL_SPANS},
+    msg::{
+        deserialize_span_data_index_map, flat::serialize_span_data_index_map, ExpandMacro,
+        ExpnGlobals, FlatTree, PanicMessage, HAS_GLOBAL_SPANS, RUST_ANALYZER_SPAN_SUPPORT,
+    },
     process::ProcMacroProcessSrv,
 };
 
@@ -166,6 +169,11 @@ impl ProcMacro {
                 call_site,
                 mixed_site,
             },
+            span_data_table: if version >= RUST_ANALYZER_SPAN_SUPPORT {
+                serialize_span_data_index_map(&span_data_table)
+            } else {
+                Vec::new()
+            },
         };
 
         let response = self
@@ -178,9 +186,14 @@ impl ProcMacro {
             msg::Response::ExpandMacro(it) => {
                 Ok(it.map(|tree| FlatTree::to_subtree_resolved(tree, version, &span_data_table)))
             }
-            msg::Response::ListMacros(..) | msg::Response::ApiVersionCheck(..) => {
-                Err(ServerError { message: "unexpected response".to_string(), io: None })
-            }
+            msg::Response::ExpandMacroExtended(it) => Ok(it.map(|resp| {
+                FlatTree::to_subtree_resolved(
+                    resp.tree,
+                    version,
+                    &deserialize_span_data_index_map(&resp.span_data_table),
+                )
+            })),
+            _ => Err(ServerError { message: "unexpected response".to_string(), io: None }),
         }
     }
 }