hacking

crates/hir-analysis/Cargo.toml

@@ -15,7 +15,7 @@ either = "1.8"
 derive_more = "0.99"
 itertools = "0.10"
 ena = "0.14"
-
+indexmap = "1.6.2"
 hir = { path = "../hir", package = "fe-hir" }
 common = { path = "../common2", package = "fe-common2" }
 macros = { path = "../macros", package = "fe-macros" }

crates/hir-analysis/src/ty/def_analysis.rs

@@ -439,10 +439,7 @@ fn check_recursive_adt_impl(
         for (ty_idx, ty) in field.iter_types(db).enumerate() {
             for field_adt_ref in ty.collect_direct_adts(db) {
                 if participants.contains(&field_adt_ref) && participants.contains(&adt) {
-                    let diag = TyLowerDiag::recursive_type(
-                        adt.name_span(db),
-                        adt_def.variant_ty_span(db, field_idx, ty_idx),
-                    );
+                    let diag = TyLowerDiag::recursive_type(field_adt_ref, adt);
                     return Some(diag.into());
                 }
             }

crates/hir-analysis/src/ty/diagnostics.rs

@@ -12,7 +12,7 @@ use crate::HirAnalysisDb;
 
 use super::{
     constraint::PredicateId,
-    ty_def::{Kind, TyId},
+    ty_def::{AdtRefId, Kind, TyId},
 };
 
 #[salsa::accumulator]
@@ -46,8 +46,8 @@ pub enum TyLowerDiag {
     NotFullyAppliedType(DynLazySpan),
     InvalidTypeArgKind(DynLazySpan, String),
     RecursiveType {
-        primary_span: DynLazySpan,
-        field_span: DynLazySpan,
+        to: AdtRefId,
+        from: AdtRefId,
     },
 
     UnboundTypeAliasParam {
@@ -95,11 +95,8 @@ impl TyLowerDiag {
         Self::InvalidTypeArgKind(span, msg)
     }
 
-    pub(super) fn recursive_type(primary_span: DynLazySpan, field_span: DynLazySpan) -> Self {
-        Self::RecursiveType {
-            primary_span,
-            field_span,
-        }
+    pub(super) fn recursive_type(to: AdtRefId, from: AdtRefId) -> Self {
+        Self::RecursiveType { to, from }
     }
 
     pub(super) fn unbound_type_alias_param(
@@ -179,21 +176,18 @@ impl TyLowerDiag {
                 span.resolve(db),
             )],
 
-            Self::RecursiveType {
-                primary_span,
-                field_span,
-            } => {
+            Self::RecursiveType { to, from } => {
                 vec![
-                    SubDiagnostic::new(
-                        LabelStyle::Primary,
-                        "recursive type definition".to_string(),
-                        primary_span.resolve(db),
-                    ),
-                    SubDiagnostic::new(
-                        LabelStyle::Secondary,
-                        "recursion occurs here".to_string(),
-                        field_span.resolve(db),
-                    ),
+                    // SubDiagnostic::new(
+                    //     LabelStyle::Primary,
+                    //     "recursive type definition".to_string(),
+                    //     primary_span.resolve(db),
+                    // ),
+                    // SubDiagnostic::new(
+                    //     LabelStyle::Secondary,
+                    //     "recursion occurs here".to_string(),
+                    //     field_span.resolve(db),
+                    // ),
                 ]
             }
 

crates/hir-analysis/src/ty/mod.rs

@@ -1,10 +1,11 @@
 use crate::HirAnalysisDb;
 use hir::{analysis_pass::ModuleAnalysisPass, hir_def::TopLevelMod};
+use indexmap::{indexmap, IndexMap};
 
 use self::{
     def_analysis::{analyze_adt, analyze_impl_trait, analyze_trait, analyze_type_alias},
     diagnostics::{
-        AdtDefDiagAccumulator, ImplTraitDefDiagAccumulator, TraitDefDiagAccumulator,
+        AdtDefDiagAccumulator, ImplTraitDefDiagAccumulator, TraitDefDiagAccumulator, TyLowerDiag,
         TypeAliasDefDiagAccumulator,
     },
     ty_def::AdtRefId,
@@ -57,11 +58,84 @@ impl<'db> ModuleAnalysisPass for TypeDefAnalysisPass<'db> {
                     .map(|c| AdtRefId::from_contract(self.db, *c)),
             );
 
-        adts.flat_map(|adt| {
-            analyze_adt::accumulated::<AdtDefDiagAccumulator>(self.db, adt).into_iter()
-        })
-        .map(|diag| diag.to_voucher())
-        .collect()
+        let mut cycles = vec![];
+        let mut diags = adts
+            .flat_map(|adt| {
+                analyze_adt::accumulated::<AdtDefDiagAccumulator>(self.db, adt).into_iter()
+            })
+            .fold(vec![], |mut accum, diag| match diag {
+                diagnostics::TyDiagCollection::Ty(TyLowerDiag::RecursiveType { to, from }) => {
+                    cycles.push(Cycle::new(to, from));
+                    accum
+                }
+                _ => {
+                    accum.push(diag);
+                    accum
+                }
+            })
+            .iter()
+            .map(|diag| diag.to_voucher())
+            .collect();
+        if !cycles.is_empty() {
+            merge_cycles(&mut cycles);
+            panic!("{:#?}", cycles);
+        }
+        diags
+    }
+}
+
+#[derive(Clone, Debug)]
+struct Cycle {
+    pub path: Vec<(AdtRefId, AdtRefId)>,
+}
+
+impl Cycle {
+    pub fn new(a: AdtRefId, b: AdtRefId) -> Self {
+        Self { path: vec![(a, b)] }
+    }
+
+    pub fn merge(&mut self, other: &mut Self) {
+        assert_eq!(self.end(), other.start());
+        self.path.append(&mut other.path);
+    }
+
+    pub fn is_complete(&self) -> bool {
+        self.start() == self.end()
+    }
+
+    pub fn start(&self) -> AdtRefId {
+        self.path[0].0
+    }
+
+    pub fn end(&self) -> AdtRefId {
+        self.path[self.path.len() - 1].1
+    }
+}
+
+fn merge_cycles(cycles: &mut Vec<Cycle>) {
+    let mut complete = false;
+
+    while !complete {
+        complete = true;
+
+        for i in 0..cycles.len() {
+            if !cycles[i].is_complete() {
+                complete = false;
+
+                for j in 0..cycles.len() {
+                    if cycles[i].end() == cycles[j].start() {
+                        let mut j_clone = cycles[j].clone();
+                        cycles[i].merge(&mut j_clone);
+                        cycles.remove(j);
+                        break;
+                    }
+                }
+
+                if !complete {
+                    break;
+                }
+            }
+        }
     }
 }
 

crates/uitest/fixtures/ty/def/recursive_type.fe

@@ -21,4 +21,4 @@ pub struct S5<T> {
 
 pub struct S6 {
     s: S5<S6>
-}
+}

crates/uitest/fixtures/ty/def/recursive_type.snap.new

@@ -0,0 +1,7 @@
+---
+source: crates/uitest/tests/ty.rs
+assertion_line: 17
+expression: diags
+input_file: crates/uitest/fixtures/ty/def/recursive_type.fe
+---
+