Implement rb_ivar_foreach.

Author: aardvark179

CHANGELOG.md

@@ -32,6 +32,7 @@ Compatibility:
 * Match tag values used by `rb_protect` and `rb_jump_tag` for the `tk` gem (#2556, @aardvark179).
 * Implement `rb_eval_cmd_kw` to support the `tk` gem (#2556, @aardvark179).
 * Fix `rb_class2name` to call `inspect` on anonymous classes like in CRuby (#2701, @aardvark179).
+* Implement `rb_ivar_foreach` to iterate over instance and class variables like in CRuby (#2701, @aardvark179).
 
 Performance:
 

lib/truffle/truffle/cext.rb

@@ -484,6 +484,34 @@ def rb_f_global_variables
     Kernel.global_variables
   end
 
+  def rb_ivar_foreach(object, func, arg)
+    keys_and_vals = []
+    if Module === object
+      keys_and_vals << :__classpath__
+      keys_and_vals << object.name
+
+      object.class_variables.each do |key|
+        keys_and_vals << key
+        keys_and_vals << object.class_variable_get(key)
+      end
+    end
+    object.instance_variables.each do |key|
+      keys_and_vals << key
+      keys_and_vals << object.instance_variable_get(key)
+    end
+
+    keys_and_vals.each_slice(2) do |key, val|
+      st_result = Truffle::Interop.execute_without_conversion(
+        func, Primitive.cext_sym2id(key), Primitive.cext_wrap(val), arg)
+
+      case st_result
+      when ST_CONTINUE
+      when ST_STOP then break
+      else raise ArgumentError, "Unknown 'func' return value: #{st_result}"
+      end
+    end
+  end
+
   def rb_obj_instance_variables(object)
     object.instance_variables
   end

src/main/c/cext/ivar.c

@@ -50,7 +50,7 @@ VALUE rb_ivar_lookup(VALUE object, const char *name, VALUE default_value) {
 
 // Needed to gem install oj
 void rb_ivar_foreach(VALUE obj, int (*func)(ANYARGS), st_data_t arg) {
-  rb_tr_error("rb_ivar_foreach not implemented");
+  polyglot_invoke(RUBY_CEXT, "rb_ivar_foreach", rb_tr_unwrap(obj), func, (void*)arg);
 }
 
 VALUE rb_attr_get(VALUE object, ID name) {

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

@@ -1530,6 +1530,17 @@ protected int rbEncMbcToCodepoint(Object string,
         }
     }
 
+    @Primitive(name = "cext_sym2id")
+    public abstract static class Sym2IDNode extends PrimitiveArrayArgumentsNode {
+
+        @Specialization
+        protected Object sym2id(RubySymbol symbol,
+                @Cached SymbolToIDNode symbolToIDNode) {
+            return symbolToIDNode.execute(symbol);
+        }
+
+    }
+
     @Primitive(name = "cext_wrap")
     public abstract static class WrapValueNode extends PrimitiveArrayArgumentsNode {