lang/cem/cemcom.ansi/label.c

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 /* $Id: label.c,v 1.8 1994/06/27 08:01:19 ceriel Exp $ */
   6 /*              L A B E L   H A N D L I N G             */
   7
   8 #include        "Lpars.h"
   9 #include        "level.h"
  10 #include        "idf.h"
  11 #include        "label.h"
  12 #include        "arith.h"
  13 #include        "def.h"
  14 #include        "type.h"
  15 #include        "stack.h"
  16
  17 extern char options[];
  18
  19 enter_label(idf, defining)
  20         register struct idf *idf;
  21 {
  22         /*      The identifier idf is entered as a label. If it is new,
  23                 it is entered into the idf list with the largest possible
  24                 scope, i.e., on the lowest possible level.
  25                 If defining, the label comes from a label statement.
  26         */
  27         register struct def *def = idf->id_label;
  28
  29         if (def)        {
  30                 if (defining && def->df_initialized)
  31                         error("redeclaration of label %s", idf->id_text);
  32         }
  33         else    {
  34                 stack_idf(idf, stack_level_of(L_LOCAL));
  35                 def = new_def();
  36                 def->df_sc = LABEL;
  37                 idf->id_label = def;
  38                 def->df_file = idf->id_file;
  39                 def->df_line = idf->id_line;
  40         }
  41         if (def->df_address == 0)
  42                 def->df_address = (arith) text_label();
  43         if (defining)
  44                 def->df_initialized = 1;
  45 }
  46
  47 unstack_label(idf)
  48         register struct idf *idf;
  49 {
  50         /*      The scope in which the label idf occurred is left.
  51         */
  52         if (!idf->id_label->df_initialized && !is_anon_idf(idf))
  53                 error("label %s not defined", idf->id_text);
  54 }