support BasicObject

lib/debug/frame_info.rb

@@ -102,7 +102,11 @@ def other_identifier
     end
 
     def callee
-      self._callee ||= self.binding&.eval('__callee__')
+      self._callee ||= begin
+                         self.binding&.eval('__callee__')
+                       rescue NameError # BasicObject
+                         nil
+                       end
     end
 
     def return_str

lib/debug/server_dap.rb

@@ -718,10 +718,10 @@ def process_dap args
               ]
             end
 
-            vars += obj.instance_variables.map{|iv|
-              variable(iv, obj.instance_variable_get(iv))
+            vars += M_INSTANCE_VARIABLES.bind_call(obj).map{|iv|
+              variable(iv, M_INSTANCE_VARIABLE_GET.bind_call(obj, iv))
             }
-            vars.unshift variable('#class', obj.class)
+            vars.unshift variable('#class', M_CLASS.bind_call(obj))
           end
         end
         event! :dap_result, :variable, req, variables: (vars || []), tid: self.id
@@ -748,7 +748,7 @@ def process_dap args
             case expr
             when /\A\@\S/
               begin
-                result = b.receiver.instance_variable_get(expr)
+                result = M_INSTANCE_VARIABLE_GET.bind_call(b.receiver, expr)
               rescue NameError
                 message = "Error: Not defined instance variable: #{expr.inspect}"
               end
@@ -759,6 +759,8 @@ def process_dap args
                   break false
                 end
               } and (message = "Error: Not defined global variable: #{expr.inspect}")
+            when /\Aself$/
+              result = b.receiver
             when /(\A((::[A-Z]|[A-Z])\w*)+)/
               unless result = search_const(b, $1)
                 message = "Error: Not defined constants: #{expr.inspect}"
@@ -768,8 +770,8 @@ def process_dap args
                 result = b.local_variable_get(expr)
               rescue NameError
                 # try to check method
-                if b.receiver.respond_to? expr, include_all: true
-                  result = b.receiver.method(expr)
+                if M_RESPOND_TO_P.bind_call(b.receiver, expr, include_all: true)
+                  result = M_METHOD.bind_call(b.receiver, expr)
                 else
                   message = "Error: Can not evaluate: #{expr.inspect}"
                 end
@@ -849,11 +851,11 @@ def variable_ name, obj, indexedVariables: 0, namedVariables: 0
         vid = 0
       end
 
-      ivnum = obj.instance_variables.size
+      ivnum = M_INSTANCE_VARIABLES.bind_call(obj).size
 
       { name: name,
         value: DEBUGGER__.safe_inspect(obj),
-        type: obj.class.name || obj.class.to_s,
+        type: (klass = M_CLASS.bind_call(obj)).name || klass.to_s,
         variablesReference: vid,
         indexedVariables: indexedVariables,
         namedVariables: namedVariables + ivnum,

lib/debug/session.rb

@@ -2310,3 +2310,12 @@ class Binding
   alias break debugger
   alias b debugger
 end
+
+# for Ruby 2.6 compatibility
+unless method(:p).unbind.respond_to? :bind_call
+  class UnboundMethod
+    def bind_call(obj, *args)
+      self.bind(obj).call(*args)
+    end
+  end
+end

lib/debug/thread_client.rb

@@ -6,6 +6,15 @@
 require_relative 'color'
 
 module DEBUGGER__
+  M_INSTANCE_VARIABLES = method(:instance_variables).unbind
+  M_INSTANCE_VARIABLE_GET = method(:instance_variable_get).unbind
+  M_CLASS = method(:class).unbind
+  M_SINGLETON_CLASS = method(:singleton_class).unbind
+  M_KIND_OF_P = method(:kind_of?).unbind
+  M_RESPOND_TO_P = method(:respond_to?).unbind
+  M_METHOD = method(:method).unbind
+  M_OBJECT_ID = method(:object_id).unbind
+
   module SkipPathHelper
     def skip_path?(path)
       CONFIG.skip? || !path ||
@@ -532,8 +541,8 @@ def show_locals pat
 
     def show_ivars pat
       if s = current_frame&.self
-        s.instance_variables.sort.each{|iv|
-          value = s.instance_variable_get(iv)
+        M_INSTANCE_VARIABLES.bind_call(s).sort.each{|iv|
+          value = M_INSTANCE_VARIABLE_GET.bind_call(s, iv)
           puts_variable_info iv, value, pat
         }
       end
@@ -542,10 +551,10 @@ def show_ivars pat
     def show_consts pat, only_self: false
       if s = current_frame&.self
         cs = {}
-        if s.kind_of? Module
+        if M_KIND_OF_P.bind_call(s, Module)
           cs[s] = :self
         else
-          s = s.class
+          s = M_CLASS.bind_call(s)
           cs[s] = :self unless only_self
         end
 
@@ -583,7 +592,7 @@ def puts_variable_info label, obj, pat
       return if pat && pat !~ label
 
       begin
-        inspected = obj.inspect
+        inspected = DEBUGGER__.safe_inspect(obj)
       rescue Exception => e
         inspected = e.inspect
       end
@@ -687,18 +696,25 @@ def show_outline expr
         o = Output.new(@output)
 
         locals = current_frame&.local_variables
-        klass  = (obj.class == Class || obj.class == Module ? obj : obj.class)
 
-        o.dump("constants", obj.constants) if obj.respond_to?(:constants)
+        klass = M_CLASS.bind_call(obj)
+        klass = obj if Class == klass || Module == klass
+
+        o.dump("constants", obj.constants) if M_RESPOND_TO_P.bind_call(obj, :constants)
         outline_method(o, klass, obj)
-        o.dump("instance variables", obj.instance_variables)
+        o.dump("instance variables", M_INSTANCE_VARIABLES.bind_call(obj))
         o.dump("class variables", klass.class_variables)
         o.dump("locals", locals.keys) if locals
       end
     end
 
     def outline_method(o, klass, obj)
-      singleton_class = begin obj.singleton_class; rescue TypeError; nil end
+      begin
+        singleton_class = M_SINGLETON_CLASS.bind_call(obj)
+      rescue TypeError
+        singleton_class = nil
+      end
+
       maps = class_method_map((singleton_class || klass).ancestors)
       maps.each do |mod, methods|
         name = mod == singleton_class ? "#{klass}.methods" : "#{mod}#methods"
@@ -1000,15 +1016,15 @@ def wait_next_action_
             begin
               obj = frame_eval args.shift, re_raise: true
               opt = args.shift
-              obj_inspect = obj.inspect
+              obj_inspect = DEBUGGER__.safe_inspect(obj)
 
               width = 50
 
               if obj_inspect.length >= width
                 obj_inspect = truncate(obj_inspect, width: width)
               end
 
-              event! :result, :trace_pass, obj.object_id, obj_inspect, opt
+              event! :result, :trace_pass, M_OBJECT_ID.bind_call(obj), obj_inspect, opt
             rescue => e
               puts e.message
               event! :result, nil

lib/debug/tracer.rb

@@ -186,7 +186,7 @@ def setup
       @tracer = TracePoint.new(:a_call){|tp|
         next if skip?(tp)
 
-        if tp.self.object_id == @obj_id
+        if M_OBJECT_ID.bind_call(tp.self) == @obj_id
           klass = tp.defined_class
           method = tp.method_id
           method_info =