Convert keyword argument to required positional hash argument for Cla…

…ss#new, Method#call, UnboundMethod#bind_call

Also add keyword argument separation warnings for Class#new and Method#call.

To allow for keyword argument to required positional hash converstion in
cfuncs, add a vm frame flag indicating the cfunc was called with an empty
keyword hash (which was removed before calling the cfunc).  The cfunc can
check this frame flag and add back an empty hash if it is passing its
arguments to another Ruby method.  Add rb_empty_keyword_given_p function
for checking if called with an empty keyword hash, and
rb_add_empty_keyword for adding back an empty hash to argv.

All of this empty keyword argument support is only for 2.7.  It will be
removed in 3.0 as Ruby 3 will not convert empty keyword arguments to
required positional hash arguments.  Comment all of the relevent code
to make it obvious this is expected to be removed.

Add rb_funcallv_kw as an public C-API function, just like rb_funcallv
but with a keyword flag.  This is used by rb_obj_call_init (internals
of Class#new).  This also required expected call_type enum with
CALL_FCALL_KW, similar to the recent addition of CALL_PUBLIC_KW.

Add rb_vm_call_kw as a internal function, used by call_method_data
(internals of Method#call and UnboundMethod#bind_call). Add tests
for UnboundMethod#bind_call keyword handling.

eval.c

@@ -907,6 +907,22 @@ rb_keyword_given_p(void)
     return rb_vm_cframe_keyword_p(GET_EC()->cfp);
 }
 
+/* -- Remove In 3.0 -- */
+int rb_vm_cframe_empty_keyword_p(const rb_control_frame_t *cfp);
+int
+rb_empty_keyword_given_p(void)
+{
+    return rb_vm_cframe_empty_keyword_p(GET_EC()->cfp);
+}
+VALUE *
+rb_add_empty_keyword(int argc, const VALUE *argv)
+{
+    VALUE *ptr = ALLOC_N(VALUE,argc+1);
+    memcpy(ptr, argv, sizeof(VALUE)*(argc));
+    ptr[argc] = rb_hash_new();
+    return ptr;
+}
+
 VALUE rb_eThreadError;
 
 /*! Declares that the current method needs a block.
@@ -1664,7 +1680,12 @@ void
 rb_obj_call_init(VALUE obj, int argc, const VALUE *argv)
 {
     PASS_PASSED_BLOCK_HANDLER();
-    rb_funcallv(obj, idInitialize, argc, argv);
+    if (rb_empty_keyword_given_p()) {
+        rb_funcallv_kw(obj, idInitialize, argc+1, rb_add_empty_keyword(argc, argv), 1);
+    }
+    else {
+        rb_funcallv_kw(obj, idInitialize, argc, argv, rb_keyword_given_p());
+    }
 }
 
 /*!

include/ruby/ruby.h

@@ -1887,6 +1887,7 @@ VALUE rb_eval_string_protect(const char*, int*);
 VALUE rb_eval_string_wrap(const char*, int*);
 VALUE rb_funcall(VALUE, ID, int, ...);
 VALUE rb_funcallv(VALUE, ID, int, const VALUE*);
+VALUE rb_funcallv_kw(VALUE, ID, int, const VALUE*, int);
 VALUE rb_funcallv_public(VALUE, ID, int, const VALUE*);
 #define rb_funcall2 rb_funcallv
 #define rb_funcall3 rb_funcallv_public

internal.h

@@ -1552,6 +1552,10 @@ void rb_class_modify_check(VALUE);
 #define id_status ruby_static_id_status
 NORETURN(VALUE rb_f_raise(int argc, VALUE *argv));
 
+/* -- Remove In 3.0 -- */
+int rb_empty_keyword_given_p(void);
+VALUE * rb_add_empty_keyword(int argc, const VALUE *argv);
+
 /* eval_error.c */
 VALUE rb_get_backtrace(VALUE info);
 

proc.c

@@ -2223,8 +2223,14 @@ call_method_data(rb_execution_context_t *ec, const struct METHOD *data,
 		 int argc, const VALUE *argv, VALUE passed_procval)
 {
     vm_passed_block_handler_set(ec, proc_to_block_handler(passed_procval));
-    return rb_vm_call(ec, data->recv, data->me->called_id, argc, argv,
-		      method_callable_method_entry(data));
+    if (rb_empty_keyword_given_p()) {
+        return rb_vm_call_kw(ec, data->recv, data->me->called_id, argc+1, rb_add_empty_keyword(argc, argv),
+                      method_callable_method_entry(data), 1);
+    }
+    else {
+        return rb_vm_call_kw(ec, data->recv, data->me->called_id, argc, argv,
+                      method_callable_method_entry(data), rb_keyword_given_p());
+    }
 }
 
 static VALUE

test/ruby/test_keyword.rb

@@ -340,7 +340,7 @@ def test_lambda_kwsplat_call
     assert_equal([1, h3], f[a: 1, **h2])
   end
 
-  def test_cfunc_kwsplat_call
+  def test_Class_new_kwsplat_call
     kw = {}
     h = {:a=>1}
     h2 = {'a'=>1}
@@ -382,8 +382,12 @@ def initialize(args)
         @args = args
       end
     end
-    assert_raise(ArgumentError) { c[**{}] }
-    assert_raise(ArgumentError) { c[**kw] }
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal(kw, c[**{}].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal(kw, c[**kw].args)
+    end
     assert_equal(h, c[**h].args)
     assert_equal(h, c[a: 1].args)
     assert_equal(h2, c[**h2].args)
@@ -408,13 +412,27 @@ def initialize(arg, **args)
         @args = [arg, args]
       end
     end
-    assert_raise(ArgumentError) { c[**{}] }
-    assert_raise(ArgumentError) { c[**kw] }
-    assert_equal([h, kw], c[**h].args)
-    assert_equal([h, kw], c[a: 1].args)
-    assert_equal([h2, kw], c[**h2].args)
-    assert_equal([h3, kw], c[**h3].args)
-    assert_equal([h3, kw], c[a: 1, **h2].args)
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([kw, kw], c[**{}].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([kw, kw], c[**kw].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([h, kw], c[**h].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([h, kw], c[a: 1].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([h2, kw], c[**h2].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([h3, kw], c[**h3].args)
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `initialize'/m) do
+      assert_equal([h3, kw], c[a: 1, **h2].args)
+    end
 
     c = Class.new(sc) do
       def initialize(arg=1, **args)
@@ -430,7 +448,7 @@ def initialize(arg=1, **args)
     assert_equal([1, h3], c[a: 1, **h2].args)
   end
 
-  def test_method_kwsplat_call
+  def test_Method_call_kwsplat_call
     kw = {}
     h = {:a=>1}
     h2 = {'a'=>1}
@@ -462,8 +480,12 @@ def c.m; end
     def c.m(args)
       args
     end
-    assert_raise(ArgumentError) { c.method(:m)[**{}] }
-    assert_raise(ArgumentError) { c.method(:m)[**kw] }
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal(kw, c.method(:m)[**{}])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal(kw, c.method(:m)[**kw])
+    end
     assert_equal(h, c.method(:m)[**h])
     assert_equal(h, c.method(:m)[a: 1])
     assert_equal(h2, c.method(:m)[**h2])
@@ -486,13 +508,27 @@ def c.m(**args)
     def c.m(arg, **args)
       [arg, args]
     end
-    assert_raise(ArgumentError) { c.method(:m)[**{}] }
-    assert_raise(ArgumentError) { c.method(:m)[**kw] }
-    assert_equal([h, kw], c.method(:m)[**h])
-    assert_equal([h, kw], c.method(:m)[a: 1])
-    assert_equal([h2, kw], c.method(:m)[**h2])
-    assert_equal([h3, kw], c.method(:m)[**h3])
-    assert_equal([h3, kw], c.method(:m)[a: 1, **h2])
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([kw, kw], c.method(:m)[**{}])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([kw, kw], c.method(:m)[**kw])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h, kw], c.method(:m)[**h])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h, kw], c.method(:m)[a: 1])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h2, kw], c.method(:m)[**h2])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h3, kw], c.method(:m)[**h3])
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h3, kw], c.method(:m)[a: 1, **h2])
+    end
 
     c.singleton_class.remove_method(:m)
     def c.m(arg=1, **args)
@@ -507,6 +543,102 @@ def c.m(arg=1, **args)
     assert_equal([1, h3], c.method(:m)[a: 1, **h2])
   end
 
+  def test_UnboundMethod_bindcall_kwsplat_call
+    kw = {}
+    h = {:a=>1}
+    h2 = {'a'=>1}
+    h3 = {'a'=>1, :a=>1}
+
+    c = Object.new
+    sc = c.singleton_class
+    def c.m(*args)
+      args
+    end
+    assert_equal([], sc.instance_method(:m).bind_call(c, **{}))
+    assert_equal([], sc.instance_method(:m).bind_call(c, **kw))
+    assert_equal([h], sc.instance_method(:m).bind_call(c, **h))
+    assert_equal([h], sc.instance_method(:m).bind_call(c, a: 1))
+    assert_equal([h2], sc.instance_method(:m).bind_call(c, **h2))
+    assert_equal([h3], sc.instance_method(:m).bind_call(c, **h3))
+    assert_equal([h3], sc.instance_method(:m).bind_call(c, a: 1, **h2))
+
+    sc.remove_method(:m)
+    def c.m; end
+    assert_nil(sc.instance_method(:m).bind_call(c, **{}))
+    assert_nil(sc.instance_method(:m).bind_call(c, **kw))
+    assert_raise(ArgumentError) { sc.instance_method(:m).bind_call(c, **h) }
+    assert_raise(ArgumentError) { sc.instance_method(:m).bind_call(c, a: 1) }
+    assert_raise(ArgumentError) { sc.instance_method(:m).bind_call(c, **h2) }
+    assert_raise(ArgumentError) { sc.instance_method(:m).bind_call(c, **h3) }
+    assert_raise(ArgumentError) { sc.instance_method(:m).bind_call(c, a: 1, **h2) }
+
+    sc.remove_method(:m)
+    def c.m(args)
+      args
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal(kw, sc.instance_method(:m).bind_call(c, **{}))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal(kw, sc.instance_method(:m).bind_call(c, **kw))
+    end
+    assert_equal(h, sc.instance_method(:m).bind_call(c, **h))
+    assert_equal(h, sc.instance_method(:m).bind_call(c, a: 1))
+    assert_equal(h2, sc.instance_method(:m).bind_call(c, **h2))
+    assert_equal(h3, sc.instance_method(:m).bind_call(c, **h3))
+    assert_equal(h3, sc.instance_method(:m).bind_call(c, a: 1, **h2))
+
+    sc.remove_method(:m)
+    def c.m(**args)
+      args
+    end
+    assert_equal(kw, sc.instance_method(:m).bind_call(c, **{}))
+    assert_equal(kw, sc.instance_method(:m).bind_call(c, **kw))
+    assert_equal(h, sc.instance_method(:m).bind_call(c, **h))
+    assert_equal(h, sc.instance_method(:m).bind_call(c, a: 1))
+    assert_equal(h2, sc.instance_method(:m).bind_call(c, **h2))
+    assert_equal(h3, sc.instance_method(:m).bind_call(c, **h3))
+    assert_equal(h3, sc.instance_method(:m).bind_call(c, a: 1, **h2))
+
+    sc.remove_method(:m)
+    def c.m(arg, **args)
+      [arg, args]
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([kw, kw], sc.instance_method(:m).bind_call(c, **{}))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([kw, kw], sc.instance_method(:m).bind_call(c, **kw))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h, kw], sc.instance_method(:m).bind_call(c, **h))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h, kw], sc.instance_method(:m).bind_call(c, a: 1))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h2, kw], sc.instance_method(:m).bind_call(c, **h2))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h3, kw], sc.instance_method(:m).bind_call(c, **h3))
+    end
+    assert_warn(/The keyword argument is passed as the last hash parameter.* for `m'/m) do
+      assert_equal([h3, kw], sc.instance_method(:m).bind_call(c, a: 1, **h2))
+    end
+
+    sc.remove_method(:m)
+    def c.m(arg=1, **args)
+      [arg=1, args]
+    end
+    assert_equal([1, kw], sc.instance_method(:m).bind_call(c, **{}))
+    assert_equal([1, kw], sc.instance_method(:m).bind_call(c, **kw))
+    assert_equal([1, h], sc.instance_method(:m).bind_call(c, **h))
+    assert_equal([1, h], sc.instance_method(:m).bind_call(c, a: 1))
+    assert_equal([1, h2], sc.instance_method(:m).bind_call(c, **h2))
+    assert_equal([1, h3], sc.instance_method(:m).bind_call(c, **h3))
+    assert_equal([1, h3], sc.instance_method(:m).bind_call(c, a: 1, **h2))
+  end
+
   def test_send_kwsplat
     kw = {}
     h = {:a=>1}

vm.c

@@ -102,6 +102,13 @@ rb_vm_cframe_keyword_p(const rb_control_frame_t *cfp)
     return VM_FRAME_CFRAME_KW_P(cfp);
 }
 
+/* -- Remove In 3.0 -- */
+int
+rb_vm_cframe_empty_keyword_p(const rb_control_frame_t *cfp)
+{
+    return VM_FRAME_CFRAME_EMPTY_KW_P(cfp);
+}
+
 VALUE
 rb_vm_frame_block_handler(const rb_control_frame_t *cfp)
 {

vm_core.h

@@ -1138,11 +1138,11 @@ typedef rb_control_frame_t *
 
 enum {
     /* Frame/Environment flag bits:
-     *   MMMM MMMM MMMM MMMM ____ _FFF FFFF EEEX (LSB)
+     *   MMMM MMMM MMMM MMMM ____ FFFF FFFF EEEX (LSB)
      *
      * X   : tag for GC marking (It seems as Fixnum)
      * EEE : 3 bits Env flags
-     * FF..: 7 bits Frame flags
+     * FF..: 8 bits Frame flags
      * MM..: 15 bits frame magic (to check frame corruption)
      */
 
@@ -1167,6 +1167,7 @@ enum {
     VM_FRAME_FLAG_LAMBDA    = 0x0100,
     VM_FRAME_FLAG_MODIFIED_BLOCK_PARAM = 0x0200,
     VM_FRAME_FLAG_CFRAME_KW = 0x0400,
+    VM_FRAME_FLAG_CFRAME_EMPTY_KW = 0x0800, /* -- Remove In 3.0 -- */
 
     /* env flag */
     VM_ENV_FLAG_LOCAL       = 0x0002,
@@ -1227,6 +1228,13 @@ VM_FRAME_CFRAME_KW_P(const rb_control_frame_t *cfp)
     return VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_CFRAME_KW) != 0;
 }
 
+/* -- Remove In 3.0 -- */
+static inline int
+VM_FRAME_CFRAME_EMPTY_KW_P(const rb_control_frame_t *cfp)
+{
+    return VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_CFRAME_EMPTY_KW) != 0;
+}
+
 static inline int
 VM_FRAME_FINISHED_P(const rb_control_frame_t *cfp)
 {
@@ -1652,6 +1660,8 @@ void rb_vm_inc_const_missing_count(void);
 void rb_vm_gvl_destroy(rb_vm_t *vm);
 VALUE rb_vm_call(rb_execution_context_t *ec, VALUE recv, VALUE id, int argc,
 		 const VALUE *argv, const rb_callable_method_entry_t *me);
+VALUE rb_vm_call_kw(rb_execution_context_t *ec, VALUE recv, VALUE id, int argc,
+                 const VALUE *argv, const rb_callable_method_entry_t *me, int kw_splat);
 MJIT_STATIC void rb_vm_pop_frame(rb_execution_context_t *ec);
 
 void rb_thread_start_timer_thread(void);