Be robust when attempting to guard unexpected objects.

Author: aardvark179

lib/cext/include/ruby/ruby.h

@@ -500,7 +500,7 @@ bool RB_TYPE_P(VALUE value, int type);
 
 #define RB_GC_GUARD(v) \
     (*__extension__ ({ \
-        VALUE *rb_gc_guarded_ptr = rb_tr_gc_guard(v);   \
+        volatile VALUE *rb_gc_guarded_ptr = rb_tr_gc_guard(&v);   \
         rb_gc_guarded_ptr;                              \
     }))
 

lib/cext/include/truffleruby/truffleruby-pre.h

@@ -50,9 +50,8 @@ MUST_INLINE VALUE rb_tr_unwrap(VALUE object) {
 
 // Needed for GC guarding
 
-MUST_INLINE VALUE *rb_tr_gc_guard(VALUE v) {
-  VALUE *ptr = &v;
-  polyglot_invoke(RUBY_CEXT, "rb_tr_gc_guard", v);
+MUST_INLINE VALUE *rb_tr_gc_guard(VALUE *ptr) {
+  polyglot_invoke(RUBY_CEXT, "rb_tr_gc_guard", *ptr);
   return ptr;
 }
 

src/main/java/org/truffleruby/cext/CExtNodes.java

@@ -14,6 +14,7 @@
 import com.oracle.truffle.api.Truffle;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CreateCast;
+import com.oracle.truffle.api.dsl.Fallback;
 import com.oracle.truffle.api.dsl.NodeChild;
 import com.oracle.truffle.api.dsl.NodeChildren;
 import com.oracle.truffle.api.dsl.Specialization;
@@ -1316,7 +1317,7 @@ protected WrapNode createWrapNode() {
     public abstract static class UnwrapValueNode extends CoreMethodArrayArgumentsNode {
 
         @Specialization
-        public Object unwrap(Object value,
+        public Object unwrap(TruffleObject value,
                 @Cached("create()") BranchProfile exceptionProfile,
                 @Cached("createUnwrapNode()") UnwrapNode unwrapNode) {
             Object object = unwrapNode.execute(value);
@@ -1359,7 +1360,7 @@ protected void setThreadLocal() {
     public abstract static class AddToMarkList extends CoreMethodArrayArgumentsNode {
 
         @Specialization
-        public DynamicObject addToMarkList(VirtualFrame frmae, Object markedObject,
+        public DynamicObject addToMarkList(VirtualFrame frmae, TruffleObject markedObject,
                 @Cached("create()") BranchProfile exceptionProfile,
                 @Cached("create()") BranchProfile noExceptionProfile,
                 @Cached("create()") UnwrapNode.ToWrapperNode toWrapperNode) {
@@ -1388,21 +1389,21 @@ protected UnwrapNode createUnwrapNode() {
     public abstract static class GCGuardNode extends CoreMethodArrayArgumentsNode {
 
         @Specialization
-        public DynamicObject addToMarkList(VirtualFrame frmae, Object guardedObject,
-                @Cached("create()") BranchProfile exceptionProfile,
+        public DynamicObject addToMarkList(VirtualFrame frmae, TruffleObject guardedObject,
+                @Cached("create()") BranchProfile noExceptionProfile,
                 @Cached("create()") UnwrapNode.ToWrapperNode toWrapperNode) {
             ValueWrapper wrappedValue = toWrapperNode.execute(guardedObject);
-            if (wrappedValue == null) {
-                exceptionProfile.enter();
-                throw new RaiseException(getContext(), coreExceptions().runtimeError(exceptionMessage(guardedObject), this));
+            if (wrappedValue != null) {
+                noExceptionProfile.enter();
+                getContext().getMarkingService().keepObject(guardedObject);
             }
-            getContext().getMarkingService().keepObject(guardedObject);
             return nil();
         }
 
-        @TruffleBoundary
-        private String exceptionMessage(Object value) {
-            return String.format("native handle not found (%s) to guard it", value);
+        @Fallback
+        public DynamicObject addToMarkList(VirtualFrame frmae, Object guardedObject) {
+            // Do nothing for unexpected objects, no matter how unexpected.
+            return nil();
         }
 
         protected UnwrapNode createUnwrapNode() {

src/main/java/org/truffleruby/cext/UnwrapNode.java

@@ -118,7 +118,7 @@ public static NativeToWrapperNode create() {
     @ImportStatic({ Message.class, ValueWrapperManager.class })
     public static abstract class ToWrapperNode extends RubyBaseNode {
 
-        public abstract ValueWrapper execute(Object value);
+        public abstract ValueWrapper execute(TruffleObject value);
 
         @Specialization
         public ValueWrapper wrappedValueWrapper(ValueWrapper value) {
@@ -143,7 +143,7 @@ public ValueWrapper unwrapTypeCastObject(TruffleObject value,
                 return nativeToWrapperNode.execute(handle);
             } else {
                 nonPointerProfile.enter();
-                throw new RaiseException(getContext(), coreExceptions().argumentError("Not a handle or a pointer", this));
+                throw null;
             }
         }
 
@@ -152,7 +152,7 @@ public static ToWrapperNode create() {
         }
     }
 
-    public abstract Object execute(Object value);
+    public abstract Object execute(TruffleObject value);
 
     @Specialization
     public Object unwrapValue(ValueWrapper value) {