lang/cem/cemcom/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 3.4 1994/06/24 12:05:05 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        "noRoption.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         if (idf->id_def)        {
  28                 register struct def *def = idf->id_def;
  29
  30                 if (def->df_sc == LABEL)        {
  31                         if (defining && def->df_initialized)
  32                                 error("redeclaration of label %s",
  33                                                                 idf->id_text);
  34                 }
  35                 else    {               /* there may still be room for it */
  36 #ifndef NOROPTION
  37                         if (options['R'] && def->df_sc == TYPEDEF)
  38                                 warning("label %s is also a typedef",
  39                                         idf->id_text);
  40 #endif
  41
  42                         if (def->df_level == level)     /* but alas, no */
  43                                 error("%s is not a label", idf->id_text);
  44                         else    {
  45                                 register int lvl = def->df_level + 1;
  46
  47 #ifndef NOROPTION
  48                                 if (options['R'] && def->df_level > L_LOCAL)
  49                                         warning("label %s is not function-wide",
  50                                                                 idf->id_text);
  51 #endif
  52                                 if (lvl < L_LOCAL)
  53                                         lvl = L_LOCAL;
  54                                 add_def(idf, LABEL, label_type, lvl);
  55                         }
  56                 }
  57         }
  58         else    {
  59                 add_def(idf, LABEL, label_type, L_LOCAL);
  60         }
  61         if (idf->id_def->df_address == 0)
  62                 idf->id_def->df_address = (arith) text_label();
  63         if (defining)
  64                 idf->id_def->df_initialized = 1;
  65 }
  66
  67 unstack_label(idf)
  68         register struct idf *idf;
  69 {
  70         /*      The scope in which the label idf occurred is left.
  71         */
  72         if (!idf->id_def->df_initialized && !is_anon_idf(idf))
  73                 error("label %s not defined", idf->id_text);
  74 }