YJIT: Properly reject keyword splat with yield

We don't have support for keyword splat anywhere, but we tried to
compile these anyways in case of `invokeblock`. This led to bad things
happening such as passing the wrong value and passing a hash into
rb_yjit_array_len(), which raised in the middle of compilation.

[Bug #20192]

bootstraptest/test_yjit.rb

@@ -11,6 +11,13 @@ assert_normal_exit %q{
   call_foo
 }
 
+# regression test for keyword splat with yield
+assert_equal 'nil', %q{
+  def splat_kw(kwargs) = yield(**kwargs)
+
+  splat_kw({}) { _1 }.inspect
+}
+
 # regression test for arity check with splat
 assert_equal '[:ae, :ae]', %q{
   def req_one(a_, b_ = 1) = raise

yjit/src/codegen.rs

@@ -6131,6 +6131,7 @@ fn gen_send_iseq(
     exit_if_tail_call(asm, ci)?;
     exit_if_has_post(asm, iseq)?;
     exit_if_has_kwrest(asm, iseq)?;
+    exit_if_kw_splat(asm, flags)?;
     exit_if_splat_and_ruby2_keywords(asm, jit, flags)?;
     exit_if_has_rest_and_captured(asm, iseq_has_rest, captured_opnd)?;
     exit_if_has_rest_and_supplying_kws(asm, iseq_has_rest, iseq, supplying_kws)?;
@@ -6261,6 +6262,9 @@ fn gen_send_iseq(
         let array = jit.peek_at_stack(&asm.ctx, if block_arg { 1 } else { 0 }) ;
         let array_length = if array == Qnil {
             0
+        } else if unsafe { !RB_TYPE_P(array, RUBY_T_ARRAY) } {
+            gen_counter_incr(asm, Counter::send_iseq_splat_not_array);
+            return None;
         } else {
             unsafe { rb_yjit_array_len(array) as u32}
         };
@@ -6939,6 +6943,11 @@ fn exit_if_has_kwrest(asm: &mut Assembler, iseq: *const rb_iseq_t) -> Option<()>
     exit_if(asm, unsafe { get_iseq_flags_has_kwrest(iseq) }, Counter::send_iseq_has_kwrest)
 }
 
+#[must_use]
+fn exit_if_kw_splat(asm: &mut Assembler, flags: u32) -> Option<()> {
+    exit_if(asm, flags & VM_CALL_KW_SPLAT != 0, Counter::send_iseq_kw_splat)
+}
+
 #[must_use]
 fn exit_if_splat_and_ruby2_keywords(asm: &mut Assembler, jit: &mut JITState, flags: u32) -> Option<()> {
     // In order to handle backwards compatibility between ruby 3 and 2

yjit/src/stats.rs

@@ -333,6 +333,7 @@ make_counters! {
     send_iseq_clobbering_block_arg,
     send_iseq_leaf_builtin_block_arg_block_param,
     send_iseq_only_keywords,
+    send_iseq_kw_splat,
     send_iseq_kwargs_req_and_opt_missing,
     send_iseq_kwargs_mismatch,
     send_iseq_has_post,
@@ -340,6 +341,7 @@ make_counters! {
     send_iseq_has_no_kw,
     send_iseq_accepts_no_kwarg,
     send_iseq_materialized_block,
+    send_iseq_splat_not_array,
     send_iseq_splat_with_opt,
     send_iseq_splat_with_kw,
     send_iseq_missing_optional_kw,