[WIP] Add TP#ivar_name to retrieve ivar's name

Author: st0012

include/ruby/debug.h

@@ -530,6 +530,16 @@ RBIMPL_ATTR_NONNULL((1))
  */
 VALUE rb_tracearg_parameters(rb_trace_arg_t *trace_arg);
 
+RBIMPL_ATTR_NONNULL((1))
+/**
+ * Queries the name of the ivar that is set.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     RUBY_Qnil  There is no ivar.
+ * @retval     otherwise  Its ivar name, in Ruby level Symbol.
+ */
+VALUE rb_tracearg_ivar_name(rb_trace_arg_t *trace_arg);
+
 RBIMPL_ATTR_NONNULL((1))
 /**
  * Queries the method name of the point where the trace is at.

object.c

@@ -2950,7 +2950,10 @@ rb_obj_ivar_set_m(VALUE obj, VALUE iv, VALUE val)
 {
     ID id = id_for_var(obj, iv, instance);
     if (!id) id = rb_intern_str(iv);
-    EXEC_EVENT_HOOK(GET_EC(), RUBY_EVENT_IVAR_SET, obj, id, 0, 0, val);
+    VALUE pair = rb_ary_new_capa(2);
+    rb_ary_push(pair, iv);
+    rb_ary_push(pair, val);
+    EXEC_EVENT_HOOK(GET_EC(), RUBY_EVENT_IVAR_SET, obj, id, 0, 0, pair);
     return rb_ivar_set(obj, id, val);
 }
 

trace_point.rb

@@ -338,6 +338,10 @@ def callee_id
     Primitive.tracepoint_attr_callee_id
   end
 
+  def ivar_name
+    Primitive.tracepoint_attr_ivar_name
+  end
+
   # Returns the class or module of the method being called.
   #
   #     class C; def foo; end; end

vm_insnhelper.c

@@ -1642,7 +1642,11 @@ vm_setinstancevariable(const rb_iseq_t *iseq, VALUE obj, ID id, VALUE val, IVC i
     attr_index_t index;
     vm_ic_atomic_shape_and_index(ic, &dest_shape_id, &index);
 
-    EXEC_EVENT_HOOK(GET_EC(), RUBY_EVENT_IVAR_SET, obj, id, 0, 0, val);
+    VALUE pair = rb_ary_new_capa(2);
+    rb_ary_push(pair, rb_id2sym(id));
+    rb_ary_push(pair, val);
+
+    EXEC_EVENT_HOOK(GET_EC(), RUBY_EVENT_IVAR_SET, obj, id, 0, 0, pair);
 
     if (UNLIKELY(UNDEF_P(vm_setivar(obj, id, val, dest_shape_id, index)))) {
         switch (BUILTIN_TYPE(obj)) {
@@ -4790,7 +4794,10 @@ vm_call_method_each_type(rb_execution_context_t *ec, rb_control_frame_t *cfp, st
         }
 
         ID mid = vm_ci_mid(ci);
-        EXEC_EVENT_HOOK(ec, RUBY_EVENT_IVAR_SET, calling->recv, mid, mid, 0, v);
+        VALUE pair = rb_ary_new_capa(2);
+        rb_ary_push(pair, rb_id2sym(mid));
+        rb_ary_push(pair, v);
+        EXEC_EVENT_HOOK(ec, RUBY_EVENT_IVAR_SET, calling->recv, mid, mid, 0, pair);
 
         return v;
 

vm_trace.c

@@ -959,6 +959,15 @@ rb_tracearg_parameters(rb_trace_arg_t *trace_arg)
     return Qnil;
 }
 
+VALUE rb_tracearg_ivar_name(rb_trace_arg_t *trace_arg)
+{
+    if (trace_arg->event == RUBY_EVENT_IVAR_SET) {
+        VALUE pair = trace_arg->data;
+        return RARRAY_AREF(pair, 0);
+    }
+    return Qnil;
+}
+
 VALUE
 rb_tracearg_method_id(rb_trace_arg_t *trace_arg)
 {
@@ -1124,6 +1133,12 @@ tracepoint_attr_parameters(rb_execution_context_t *ec, VALUE tpval)
     return rb_tracearg_parameters(get_trace_arg());
 }
 
+static VALUE
+tracepoint_attr_ivar_name(rb_execution_context_t *ec, VALUE tpval)
+{
+    return rb_tracearg_ivar_name(get_trace_arg());
+}
+
 static VALUE
 tracepoint_attr_method_id(rb_execution_context_t *ec, VALUE tpval)
 {