bail on compilation if the comptime receiver is frozen

4 files changed, 14 insertions, 0 deletions

diff --git a/yjit/bindgen/src/main.rs b/yjit/bindgen/src/main.rs
index 1b6838bb2e..0fa2c72d66 100644
--- a/yjit/bindgen/src/main.rs
+++ b/yjit/bindgen/src/main.rs
@@ -95,6 +95,7 @@ fn main() {
 
         // From ruby/internal/intern/object.h
         .allowlist_function("rb_obj_is_kind_of")
+        .allowlist_function("rb_obj_frozen_p")
 
         // From ruby/internal/encoding/encoding.h
         .allowlist_type("ruby_encoding_consts")
diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs
index 6b2ef6806f..c60264078b 100644
--- a/yjit/src/codegen.rs
+++ b/yjit/src/codegen.rs
@@ -2191,6 +2191,12 @@ fn gen_setinstancevariable(
     let comptime_receiver = jit_peek_at_self(jit);
     let comptime_val_klass = comptime_receiver.class_of();
 
+    // If the comptime receiver is frozen, writing an IV will raise an exception
+    // and we don't want to JIT code to deal with that situation.
+    if comptime_receiver.is_frozen() {
+        return CantCompile;
+    }
+
     // Check if the comptime class uses a custom allocator
     let custom_allocator = unsafe { rb_get_alloc_func(comptime_val_klass) };
     let uses_custom_allocator = match custom_allocator {
diff --git a/yjit/src/cruby.rs b/yjit/src/cruby.rs
index c2f5790620..b6228fe64b 100644
--- a/yjit/src/cruby.rs
+++ b/yjit/src/cruby.rs
@@ -394,6 +394,10 @@ impl VALUE {
         unsafe { CLASS_OF(self) }
     }
 
+    pub fn is_frozen(self) -> bool {
+        unsafe { rb_obj_frozen_p(self) != VALUE(0) }
+    }
+
     pub fn shape_id_of(self) -> u32 {
         unsafe { rb_shape_get_shape_id(self) }
     }
diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs
index e797c19104..d2ad67e802 100644
--- a/yjit/src/cruby_bindings.inc.rs
+++ b/yjit/src/cruby_bindings.inc.rs
@@ -358,6 +358,9 @@ extern "C" {
     pub fn rb_obj_is_kind_of(obj: VALUE, klass: VALUE) -> VALUE;
 }
 extern "C" {
+    pub fn rb_obj_frozen_p(obj: VALUE) -> VALUE;
+}
+extern "C" {
     pub fn rb_backref_get() -> VALUE;
 }
 extern "C" {