ack/lang/cem/cemcom.ansi/label.c

60 lines
1.5 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* $Header$ */
/* L A B E L H A N D L I N G */
#include "Lpars.h"
#include "level.h"
#include "idf.h"
#include "label.h"
#include "arith.h"
#include "def.h"
#include "type.h"
extern char options[];
enter_label(idf, defining)
register struct idf *idf;
{
/* The identifier idf is entered as a label. If it is new,
it is entered into the idf list with the largest possible
scope, i.e., on the lowest possible level.
If defining, the label comes from a label statement.
*/
register struct def *def = idf->id_def;
if (def) {
if (def->df_sc == LABEL) {
if (defining && def->df_initialized)
error("redeclaration of label %s",
idf->id_text);
}
else { /* there may still be room for it */
if (def->df_level == level) /* but alas, no */
error("%s is not a label", idf->id_text);
else {
add_def(idf, LABEL, label_type, L_LOCAL);
}
}
}
else {
add_def(idf, LABEL, label_type, L_LOCAL);
}
def = idf->id_def; /* might be changed by 1 of the 2 add_defs */
if (def->df_address == 0)
def->df_address = (arith) text_label();
if (defining)
def->df_initialized = 1;
}
unstack_label(idf)
register struct idf *idf;
{
/* The scope in which the label idf occurred is left.
*/
if (!idf->id_def->df_initialized && !is_anon_idf(idf))
error("label %s not defined", idf->id_text);
}