Add TracePoint#parameters

It can be used to get the parameters' information of method and block.
There was no way to get block parameters.
It was possible but ineffective to get method parameters via Method
object: `tp.defined_class.method(tp.method_id).parameters`
TracePoint#parameters allows us to get the information easily.
[Feature #14694]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63562 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 49 insertions, 0 deletions

diff --git a/vm_trace.c b/vm_trace.c
index bae4649cf7..10ee1ca18e 100644
--- a/vm_trace.c
+++ b/vm_trace.c
@@ -805,6 +805,45 @@ fill_id_and_klass(rb_trace_arg_t *trace_arg)
 }
 
 VALUE
+rb_tracearg_parameters(rb_trace_arg_t *trace_arg)
+{
+    switch(trace_arg->event) {
+      case RUBY_EVENT_CALL:
+      case RUBY_EVENT_RETURN:
+      case RUBY_EVENT_B_CALL:
+      case RUBY_EVENT_B_RETURN: {
+	const rb_control_frame_t *cfp = rb_vm_get_ruby_level_next_cfp(trace_arg->ec, trace_arg->cfp);
+	if (cfp) {
+            int is_proc = 0;
+            if (VM_FRAME_TYPE(cfp) == VM_FRAME_MAGIC_BLOCK && !VM_FRAME_LAMBDA_P(cfp)) {
+                is_proc = 1;
+            }
+	    return rb_iseq_parameters(cfp->iseq, is_proc);
+	}
+	break;
+      }
+      case RUBY_EVENT_C_CALL:
+      case RUBY_EVENT_C_RETURN: {
+	fill_id_and_klass(trace_arg);
+	if (trace_arg->klass && trace_arg->id) {
+	    const rb_method_entry_t *me;
+	    VALUE iclass = Qnil;
+	    me = rb_method_entry_without_refinements(trace_arg->klass, trace_arg->id, &iclass);
+	    return rb_unnamed_parameters(rb_method_entry_arity(me));
+	}
+	break;
+      }
+      case RUBY_EVENT_RAISE:
+      case RUBY_EVENT_LINE:
+      case RUBY_EVENT_CLASS:
+      case RUBY_EVENT_END:
+	rb_raise(rb_eRuntimeError, "not supported by this event");
+	break;
+    }
+    return Qnil;
+}
+
+VALUE
 rb_tracearg_method_id(rb_trace_arg_t *trace_arg)
 {
     fill_id_and_klass(trace_arg);
@@ -920,6 +959,15 @@ tracepoint_attr_path(VALUE tpval)
 }
 
 /*
+ * Return the parameters of the method or block that the current hook belongs to
+ */
+static VALUE
+tracepoint_attr_parameters(VALUE tpval)
+{
+    return rb_tracearg_parameters(get_trace_arg());
+}
+
+/*
  * Return the name at the definition of the method being called
  */
 static VALUE
@@ -1502,6 +1550,7 @@ Init_vm_trace(void)
     rb_define_method(rb_cTracePoint, "event", tracepoint_attr_event, 0);
     rb_define_method(rb_cTracePoint, "lineno", tracepoint_attr_lineno, 0);
     rb_define_method(rb_cTracePoint, "path", tracepoint_attr_path, 0);
+    rb_define_method(rb_cTracePoint, "parameters", tracepoint_attr_parameters, 0);
     rb_define_method(rb_cTracePoint, "method_id", tracepoint_attr_method_id, 0);
     rb_define_method(rb_cTracePoint, "callee_id", tracepoint_attr_callee_id, 0);
     rb_define_method(rb_cTracePoint, "defined_class", tracepoint_attr_defined_class, 0);