Merge pull request #20232 from ShoyuVanilla/issue-20225

fix: Normalize projection types before calculating memory maps

Author: ShoyuVanilla

crates/hir-ty/src/display.rs

@@ -795,6 +795,14 @@ fn render_const_scalar(
                 let Some(bytes) = memory_map.get(addr, size_one * count) else {
                     return f.write_str("<ref-data-not-available>");
                 };
+                let expected_len = count * size_one;
+                if bytes.len() < expected_len {
+                    never!(
+                        "Memory map size is too small. Expected {expected_len}, got {}",
+                        bytes.len(),
+                    );
+                    return f.write_str("<layout-error>");
+                }
                 f.write_str("&[")?;
                 let mut first = true;
                 for i in 0..count {

crates/hir-ty/src/mir/eval.rs

@@ -31,8 +31,8 @@ use syntax::{SyntaxNodePtr, TextRange};
 use triomphe::Arc;
 
 use crate::{
-    CallableDefId, ClosureId, ComplexMemoryMap, Const, ConstData, ConstScalar, FnDefId, Interner,
-    MemoryMap, Substitution, ToChalk, TraitEnvironment, Ty, TyBuilder, TyExt, TyKind,
+    AliasTy, CallableDefId, ClosureId, ComplexMemoryMap, Const, ConstData, ConstScalar, FnDefId,
+    Interner, MemoryMap, Substitution, ToChalk, TraitEnvironment, Ty, TyBuilder, TyExt, TyKind,
     consteval::{ConstEvalError, intern_const_scalar, try_const_usize},
     db::{HirDatabase, InternedClosure},
     display::{ClosureStyle, DisplayTarget, HirDisplay},
@@ -2195,7 +2195,7 @@ impl Evaluator<'_> {
                         }
                     }
                 }
-                chalk_ir::TyKind::Array(inner, len) => {
+                TyKind::Array(inner, len) => {
                     let len = match try_const_usize(this.db, len) {
                         Some(it) => it as usize,
                         None => not_supported!("non evaluatable array len in patching addresses"),
@@ -2213,7 +2213,7 @@ impl Evaluator<'_> {
                         )?;
                     }
                 }
-                chalk_ir::TyKind::Tuple(_, subst) => {
+                TyKind::Tuple(_, subst) => {
                     let layout = this.layout(ty)?;
                     for (id, ty) in subst.iter(Interner).enumerate() {
                         let ty = ty.assert_ty_ref(Interner); // Tuple only has type argument
@@ -2229,7 +2229,7 @@ impl Evaluator<'_> {
                         )?;
                     }
                 }
-                chalk_ir::TyKind::Adt(adt, subst) => match adt.0 {
+                TyKind::Adt(adt, subst) => match adt.0 {
                     AdtId::StructId(s) => {
                         let data = s.fields(this.db);
                         let layout = this.layout(ty)?;
@@ -2280,6 +2280,10 @@ impl Evaluator<'_> {
                     }
                     AdtId::UnionId(_) => (),
                 },
+                TyKind::Alias(AliasTy::Projection(proj)) => {
+                    let ty = this.db.normalize_projection(proj.clone(), this.trait_env.clone());
+                    rec(this, bytes, &ty, locals, mm, stack_depth_limit - 1)?;
+                }
                 _ => (),
             }
             Ok(())

crates/ide/src/hover/tests.rs

@@ -10985,3 +10985,41 @@ fn has_docs$0() {}
         "#]],
     );
 }
+
+#[test]
+fn regression_20225() {
+    check(
+        r#"
+//- minicore: coerce_unsized
+trait Trait {
+    type Type<'a, T: ?Sized + 'a>;
+}
+
+enum Borrowed {}
+
+impl Trait for Borrowed {
+    type Type<'a, T: ?Sized + 'a> = &'a T;
+}
+
+enum Enum<'a, T: Trait + 'a> {
+    Variant1(T::Type<'a, [Enum<'a, T>]>),
+    Variant2,
+}
+
+impl Enum<'_, Borrowed> {
+    const CONSTANT$0: Self = Self::Variant1(&[Self::Variant2]);
+}
+    "#,
+        expect![[r#"
+            *CONSTANT*
+
+            ```rust
+            ra_test_fixture::Enum
+            ```
+
+            ```rust
+            const CONSTANT: Self = Variant1(&[Variant2])
+            ```
+        "#]],
+    );
+}