Hash splat `**` should not be ignored.

Implemented by adding `OP_HASHCAT` that merges hashes.

include/mruby/ops.h

@@ -94,6 +94,7 @@ OPCODE(STRING,     BB)       /* R(a) = str_dup(Lit(b)) */
 OPCODE(STRCAT,     B)        /* str_cat(R(a),R(a+1)) */
 OPCODE(HASH,       BB)       /* R(a) = hash_new(R(a),R(a+1)..R(a+b)) */
 OPCODE(HASHADD,    BB)       /* R(a) = hash_push(R(a),R(a+1)..R(a+b)) */
+OPCODE(HASHCAT,    B)        /* R(a) = hash_cat(R(a),R(a+1)) */
 OPCODE(LAMBDA,     BB)       /* R(a) = lambda(SEQ[b],L_LAMBDA) */
 OPCODE(BLOCK,      BB)       /* R(a) = lambda(SEQ[b],L_BLOCK) */
 OPCODE(METHOD,     BB)       /* R(a) = lambda(SEQ[b],L_METHOD) */

mrbgems/mruby-compiler/core/codegen.c

@@ -1874,15 +1874,32 @@ codegen(codegen_scope *s, node *tree, int val)
       mrb_bool update = FALSE;
 
       while (tree) {
-        if (nt == NODE_KW_HASH &&
-            nint(tree->car->car->car) == NODE_KW_REST_ARGS) {
-          tree = tree->cdr;
-          continue;
+        if (nint(tree->car->car->car) == NODE_KW_REST_ARGS) {
+          if (len > 0) {
+            pop_n(len*2);
+            if (!update) {
+              genop_2(s, OP_HASH, cursp(), len);
+            }
+            else {
+              pop();
+              genop_2(s, OP_HASHADD, cursp(), len);
+            }
+            push();
+          }
+          codegen(s, tree->car->cdr, VAL);
+          if (len > 0) {
+            pop(); pop();
+            genop_1(s, OP_HASHCAT, cursp());
+            push();
+          }
+          update = TRUE;
+          len = 0;
+        }
+        else {
+          codegen(s, tree->car->car, VAL);
+          codegen(s, tree->car->cdr, VAL);
+          len++;
         }
-
-        codegen(s, tree->car->car, val);
-        codegen(s, tree->car->cdr, val);
-        len++;
         tree = tree->cdr;
         if (val && len == 255) {
           pop_n(len*2);
@@ -1905,7 +1922,9 @@ codegen(codegen_scope *s, node *tree, int val)
         }
         else {
           pop();
-          genop_2(s, OP_HASHADD, cursp(), len);
+          if (len > 0) {
+            genop_2(s, OP_HASHADD, cursp(), len);
+          }
         }
         push();
       }

src/codedump.c

@@ -416,7 +416,11 @@ codedump(mrb_state *mrb, mrb_irep *irep)
       print_lv_a(mrb, irep, a);
       break;
     CASE(OP_HASHADD, BB):
-      printf("OP_HASHADD\tR%d\t%d", a, b);
+      printf("OP_HASHADD\tR%d\t%d\t", a, b);
+      print_lv_a(mrb, irep, a);
+      break;
+    CASE(OP_HASHCAT, B):
+      printf("OP_HASHCAT\tR%d\t", a);
       print_lv_a(mrb, irep, a);
       break;
 

src/vm.c

@@ -2710,6 +2710,11 @@ RETRY_TRY_BLOCK:
       mrb_gc_arena_restore(mrb, ai);
       NEXT;
     }
+    CASE(OP_HASHCAT, B) {
+      mrb_hash_merge(mrb, regs[a], regs[a+1]);
+      mrb_gc_arena_restore(mrb, ai);
+      NEXT;
+    }
 
     CASE(OP_LAMBDA, BB)
     c = OP_L_LAMBDA;