Revert "Raise RuntimeError if Kernel#binding is called from a non-Ruby frame"

This reverts commit 343ea9967e.

This causes an assertion failure with -DRUBY_DEBUG=1 -DRGENGC_CHECK_MODE=2

bootstraptest/test_yjit.rb

@@ -1,3 +1,34 @@
+assert_equal '2022', %q{
+ def contrivance(hash, key)
+    # Expect this to compile to an `opt_aref`.
+    hash[key]
+
+    # The [] call above tracks that the `hash` local has a VALUE that
+    # is a heap pointer and the guard for the Kernel#itself call below
+    # doesn't check that it's a heap pointer VALUE.
+    #
+    # As you can see from the crash, the call to rb_hash_aref() can set the
+    # `hash` local, making eliding the heap object guard unsound.
+    hash.itself
+  end
+
+  # This is similar to ->(recv, mid) { send(recv, mid).local_variable_set(...) }.
+  # By composing we avoid creating new Ruby frames and so sending :binding
+  # captures the environment of the frame that does the missing key lookup.
+  # We use it to capture the environment inside of `contrivance`.
+  cap_then_set =
+    Kernel.instance_method(:send).method(:bind_call).to_proc >>
+      ->(binding) { binding.local_variable_set(:hash, 2022) }
+  special_missing = Hash.new(&cap_then_set)
+
+  # Make YJIT speculate that it's a hash and generate code
+  # that calls rb_hash_aref().
+  contrivance({}, :warmup)
+  contrivance({}, :warmup)
+
+  contrivance(special_missing, :binding)
+}
+
 assert_equal '18374962167983112447', %q{
   # regression test for incorrectly discarding 32 bits of a pointer when it
   # comes to default values.

spec/ruby/optional/capi/binding_spec.rb

@@ -8,14 +8,6 @@ describe "CApiBindingSpecs" do
   end
 
   describe "Kernel#binding" do
-    ruby_version_is '3.2' do
-      it "raises when called from C" do
-        foo = 14
-        -> { @b.get_binding }.should raise_error(RuntimeError)
-      end
-    end
-
-    ruby_version_is ''...'3.2' do
     it "gives the top-most Ruby binding when called from C" do
       foo = 14
       b = @b.get_binding
@@ -24,5 +16,4 @@ describe "CApiBindingSpecs" do
       foo.should == 12
     end
   end
-  end
 end

test/ruby/test_proc.rb

@@ -445,11 +445,6 @@ class TestProc < Test::Unit::TestCase
     assert_equal(@@line_of_source_location_test, lineno, 'Bug #2427')
   end
 
-  def test_binding_error_unless_ruby_frame
-    define_singleton_method :binding_from_c!, method(:binding).to_proc >> ->(bndg) {bndg}
-    assert_raise(RuntimeError) { binding_from_c! }
-  end
-
   def test_proc_lambda
     assert_raise(ArgumentError) { proc }
     assert_raise(ArgumentError) { assert_warn(/deprecated/) {lambda} }

test/ruby/test_settracefunc.rb

@@ -594,7 +594,7 @@ CODE
 
     eval <<-EOF.gsub(/^.*?: /, ""), nil, 'xyzzy'
     1: set_trace_func(lambda{|event, file, line, id, binding, klass|
-    2:   events << [event, line, file, klass, id, binding&.eval('self'), binding&.eval("_local_var")] if file == 'xyzzy'
+    2:   events << [event, line, file, klass, id, binding.eval('self'), binding.eval("_local_var")] if file == 'xyzzy'
     3: })
     4: 1.times{|;_local_var| _local_var = :inner
     5:   tap{}
@@ -619,31 +619,31 @@ CODE
 
     answer_events = [
      #
-     [:c_return, 1, "xyzzy", TracePoint,  :trace,           TracePoint,  nil,  nil],
+     [:c_return, 1, "xyzzy", TracePoint,  :trace,           TracePoint,  :outer,  trace],
      [:line,     4, 'xyzzy', self.class,  method,           self,        :outer, :nothing],
-     [:c_call,   4, 'xyzzy', Integer,     :times,           1,           nil, nil],
+     [:c_call,   4, 'xyzzy', Integer,     :times,           1,           :outer, :nothing],
      [:line,     4, 'xyzzy', self.class,  method,           self,        nil,    :nothing],
      [:line,     5, 'xyzzy', self.class,  method,           self,        :inner, :nothing],
-     [:c_return, 4, "xyzzy", Integer,     :times,           1,           nil, nil],
+     [:c_return, 4, "xyzzy", Integer,     :times,           1,           :outer, 1],
      [:line,     7, 'xyzzy', self.class,  method,           self,        :outer, :nothing],
-     [:c_call,   7, "xyzzy", Class,       :inherited,       Object,      nil, nil],
+     [:c_call,   7, "xyzzy", Class,       :inherited,       Object,      :outer, :nothing],
-     [:c_return, 7, "xyzzy", Class,       :inherited,       Object,      nil, nil],
+     [:c_return, 7, "xyzzy", Class,       :inherited,       Object,      :outer, nil],
-     [:c_call,   7, "xyzzy", Class,       :const_added,     Object,      nil, nil],
+     [:c_call,   7, "xyzzy", Class,       :const_added,     Object,      :outer, :nothing],
-     [:c_return, 7, "xyzzy", Class,       :const_added,     Object,      nil, nil],
+     [:c_return, 7, "xyzzy", Class,       :const_added,     Object,      :outer, nil],
      [:class,    7, "xyzzy", nil,         nil,              xyzzy.class, nil,    :nothing],
      [:line,     8, "xyzzy", nil,         nil,              xyzzy.class, nil,    :nothing],
      [:line,     9, "xyzzy", nil,         nil,              xyzzy.class, :XYZZY_outer, :nothing],
-     [:c_call,   9, "xyzzy", Module,      :method_added,    xyzzy.class, nil, nil],
+     [:c_call,   9, "xyzzy", Module,      :method_added,    xyzzy.class, :XYZZY_outer, :nothing],
-     [:c_return, 9, "xyzzy", Module,      :method_added,    xyzzy.class, nil, nil],
+     [:c_return, 9, "xyzzy", Module,      :method_added,    xyzzy.class, :XYZZY_outer, nil],
      [:line,    13, "xyzzy", nil,         nil,              xyzzy.class, :XYZZY_outer, :nothing],
-     [:c_call,  13, "xyzzy", Module,      :method_added,    xyzzy.class, nil, nil],
+     [:c_call,  13, "xyzzy", Module,      :method_added,    xyzzy.class, :XYZZY_outer, :nothing],
-     [:c_return,13, "xyzzy", Module,      :method_added,    xyzzy.class, nil, nil],
+     [:c_return,13, "xyzzy", Module,      :method_added,    xyzzy.class, :XYZZY_outer, nil],
      [:end,     17, "xyzzy", nil,         nil,              xyzzy.class, :XYZZY_outer, :nothing],
      [:line,    18, "xyzzy", TestSetTraceFunc, method,      self,        :outer, :nothing],
-     [:c_call,  18, "xyzzy", Class,       :new,             xyzzy.class, nil, nil],
+     [:c_call,  18, "xyzzy", Class,       :new,             xyzzy.class, :outer, :nothing],
-     [:c_call,  18, "xyzzy", BasicObject, :initialize,      xyzzy,       nil, nil],
+     [:c_call,  18, "xyzzy", BasicObject, :initialize,      xyzzy,       :outer, :nothing],
-     [:c_return,18, "xyzzy", BasicObject, :initialize,      xyzzy,       nil, nil],
+     [:c_return,18, "xyzzy", BasicObject, :initialize,      xyzzy,       :outer, nil],
-     [:c_return,18, "xyzzy", Class,       :new,             xyzzy.class, nil, nil],
+     [:c_return,18, "xyzzy", Class,       :new,             xyzzy.class, :outer, xyzzy],
      [:line,    19, "xyzzy", TestSetTraceFunc, method,      self, :outer, :nothing],
      [:call,     9, "xyzzy", xyzzy.class, :foo,             xyzzy,       nil,  :nothing],
      [:line,    10, "xyzzy", xyzzy.class, :foo,             xyzzy,       nil,  :nothing],
@@ -654,19 +654,19 @@ CODE
      [:return,  16, "xyzzy", xyzzy.class, :bar,             xyzzy,       :XYZZY_bar, xyzzy],
      [:return,  12, "xyzzy", xyzzy.class, :foo,             xyzzy,       :XYZZY_foo, xyzzy],
      [:line,    20, "xyzzy", TestSetTraceFunc, method,      self,        :outer, :nothing],
-     [:c_call,  20, "xyzzy", Kernel,      :raise,           self,        nil, nil],
+     [:c_call,  20, "xyzzy", Kernel,      :raise,           self,        :outer, :nothing],
-     [:c_call,  20, "xyzzy", Exception,   :exception,       RuntimeError, nil, nil],
+     [:c_call,  20, "xyzzy", Exception,   :exception,       RuntimeError, :outer, :nothing],
-     [:c_call,  20, "xyzzy", Exception,   :initialize,      raised_exc,  nil, nil],
+     [:c_call,  20, "xyzzy", Exception,   :initialize,      raised_exc,  :outer, :nothing],
-     [:c_return,20, "xyzzy", Exception,   :initialize,      raised_exc,  nil, nil],
+     [:c_return,20, "xyzzy", Exception,   :initialize,      raised_exc,  :outer, raised_exc],
-     [:c_return,20, "xyzzy", Exception,   :exception,       RuntimeError, nil, nil],
+     [:c_return,20, "xyzzy", Exception,   :exception,       RuntimeError, :outer, raised_exc],
-     [:c_return,20, "xyzzy", Kernel,      :raise,           self,        nil, nil],
+     [:c_return,20, "xyzzy", Kernel,      :raise,           self,        :outer, nil],
-     [:c_call,  20, "xyzzy", Exception,   :backtrace,       raised_exc,  nil, nil],
+     [:c_call,  20, "xyzzy", Exception,   :backtrace,       raised_exc,  :outer, :nothing],
-     [:c_return,20, "xyzzy", Exception,   :backtrace,       raised_exc,  nil, nil],
+     [:c_return,20, "xyzzy", Exception,   :backtrace,       raised_exc,  :outer, nil],
      [:raise,   20, "xyzzy", TestSetTraceFunc, :trace_by_tracepoint, self, :outer, raised_exc],
-     [:c_call,  20, "xyzzy", Module,      :===,             RuntimeError, nil, nil],
+     [:c_call,  20, "xyzzy", Module,      :===,             RuntimeError,:outer, :nothing],
-     [:c_return,20, "xyzzy", Module,      :===,             RuntimeError, nil, nil],
+     [:c_return,20, "xyzzy", Module,      :===,             RuntimeError,:outer, true],
      [:line,    21, "xyzzy", TestSetTraceFunc, method,      self,        :outer, :nothing],
-     [:c_call,  21, "xyzzy", TracePoint,  :disable,         trace,       nil, nil],
+     [:c_call,  21, "xyzzy", TracePoint,  :disable,         trace,       :outer, :nothing],
      ]
     return events, answer_events
   end

vm.c

@@ -1233,12 +1233,15 @@ rb_vm_make_binding(const rb_execution_context_t *ec, const rb_control_frame_t *s
     if (cfp == 0 || ruby_level_cfp == 0) {
 	rb_raise(rb_eRuntimeError, "Can't create Binding Object on top of Fiber.");
     }
-    if (!VM_FRAME_RUBYFRAME_P(src_cfp) &&
+
-        !VM_FRAME_RUBYFRAME_P(RUBY_VM_PREVIOUS_CONTROL_FRAME(src_cfp))) {
+    while (1) {
-        rb_raise(rb_eRuntimeError, "Cannot create Binding object for non-Ruby caller");
+	envval = vm_make_env_object(ec, cfp);
+	if (cfp == ruby_level_cfp) {
+	    break;
+	}
+	cfp = rb_vm_get_binding_creatable_next_cfp(ec, RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp));
     }
 
-    envval = vm_make_env_object(ec, cfp);
     bindval = rb_binding_alloc(rb_cBinding);
     GetBindingPtr(bindval, bind);
     vm_bind_update_env(bindval, bind, envval);

vm_trace.c

@@ -721,14 +721,7 @@ call_trace_func(rb_event_flag_t event, VALUE proc, VALUE self, ID id, VALUE klas
     argv[1] = filename;
     argv[2] = INT2FIX(line);
     argv[3] = id ? ID2SYM(id) : Qnil;
-    argv[4] = Qnil;
+    argv[4] = (self && (filename != Qnil)) ? rb_binding_new() : Qnil;
-    if (self && (filename != Qnil) &&
-        event != RUBY_EVENT_C_CALL &&
-        event != RUBY_EVENT_C_RETURN &&
-        (VM_FRAME_RUBYFRAME_P(ec->cfp) ||
-         VM_FRAME_RUBYFRAME_P(RUBY_VM_PREVIOUS_CONTROL_FRAME(ec->cfp)))) {
-        argv[4] = rb_binding_new();
-    }
     argv[5] = klass ? klass : Qnil;
 
     rb_proc_call_with_block(proc, 6, argv, Qnil);