Added Nitfol and Frotz source code.

[rodin/chimara.git] / interpreters / nitfol / op_call.c

diff --git a/interpreters/nitfol/op_call.c b/interpreters/nitfol/op_call.c
new file mode 100644 (file)
index 0000000..ebedf4f
--- /dev/null
+++ b/interpreters/nitfol/op_call.c
@@ -0,0 +1,98 @@
+/*  Nitfol - z-machine interpreter using Glk for output.
+    Copyright (C) 1999  Evin Robertson
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+
+    The author can be reached at nitfol@deja.com
+*/
+#include "nitfol.h"
+
+void mop_call(zword dest, unsigned num_args, zword *args, int result_var)
+{
+  unsigned i;
+  offset destPC;
+  unsigned num_local;
+
+  if(dest == 0) {
+    check_set_var(result_var, 0);
+    return;
+  }
+
+  destPC = UNPACKR(dest);
+
+  /*  printf("call %x -> %x\n", oldPC, destPC); */
+  
+#ifndef FAST
+  if(destPC > game_size) {
+    n_show_error(E_INSTR, "call past end of story", dest);
+    check_set_var(result_var, 0);
+    return;
+  }
+#endif
+  
+  num_local = HIBYTE(destPC); /* first byte is # of local variables */
+
+#ifndef FAST
+  if(num_local > 15) {
+    n_show_error(E_INSTR, "call to non-function (initial byte > 15)", dest);
+    check_set_var(result_var, 0);
+    return;
+  }
+#endif
+
+  destPC++;     /* Go on past the variable count */
+
+  if(zversion < 5) {
+    for(i = num_args; i < num_local; i++)
+      args[i] = HIWORD(destPC + i * ZWORD_SIZE);  /* Load default locals */
+    destPC += num_local * ZWORD_SIZE;
+  } else {
+    for(i = num_args; i < num_local; i++)
+      args[i] = 0;                                /* locals default to zero */
+  }
+
+  add_stack_frame(PC, num_local, args, num_args, result_var);
+
+  PC = destPC;
+
+  /*n_show_debug(E_DEBUG, "function starting", dest);*/
+}
+
+void op_call_n(void)
+{
+  mop_call(operand[0], numoperands - 1, operand + 1, -1);
+}
+
+void op_call_s(void)
+{
+  zbyte ret_var = HIBYTE(PC);
+  PC++;
+  mop_call(operand[0], numoperands - 1, operand + 1, ret_var);
+}
+
+void op_ret(void)
+{
+  mop_func_return(operand[0]);
+}
+
+void op_rfalse(void)
+{
+  mop_func_return(0);
+}
+
+void op_rtrue(void)
+{
+  mop_func_return(1);
+}