281 lines
6.8 KiB
C
281 lines
6.8 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".
|
|
*/
|
|
/* $Id$ */
|
|
/* S T A C K / U N S T A C K R O U T I N E S */
|
|
|
|
#include "lint.h"
|
|
#include "nofloat.h"
|
|
#include <system.h>
|
|
#ifndef LINT
|
|
#include <em.h>
|
|
#else
|
|
#include "l_em.h"
|
|
#endif /* LINT */
|
|
#include "debug.h"
|
|
#include "botch_free.h"
|
|
#include <alloc.h>
|
|
#include "Lpars.h"
|
|
#include "arith.h"
|
|
#include "stack.h"
|
|
#include "type.h"
|
|
#include "idf.h"
|
|
#include "def.h"
|
|
#include "struct.h"
|
|
#include "level.h"
|
|
#include "mes.h"
|
|
#include "noRoption.h"
|
|
|
|
extern char options[];
|
|
|
|
static struct stack_level UniversalLevel;
|
|
struct stack_level *local_level = &UniversalLevel;
|
|
/* The main reason for having this secondary stacking
|
|
mechanism besides the linked lists pointed to by the idf's
|
|
is efficiency.
|
|
To remove the idf's of a given level, one could scan the
|
|
hash table and chase down the idf chains; with a hash
|
|
table size of 100 this is feasible, but with a size of say
|
|
100000 this becomes painful. Therefore all idf's are also
|
|
kept in a stack of sets, one set for each level.
|
|
*/
|
|
|
|
int level; /* Always equal to local_level->sl_level. */
|
|
|
|
stack_level() {
|
|
/* A new level is added on top of the identifier stack.
|
|
*/
|
|
register struct stack_level *stl = new_stack_level();
|
|
register struct stack_level *loclev = local_level;
|
|
|
|
loclev->sl_next = stl;
|
|
stl->sl_previous = loclev;
|
|
stl->sl_level = ++level;
|
|
stl->sl_max_block = loclev->sl_max_block;
|
|
local_level = stl;
|
|
#ifdef LINT
|
|
lint_start_local();
|
|
#endif /* LINT */
|
|
}
|
|
|
|
stack_idf(idf, stl)
|
|
struct idf *idf;
|
|
register struct stack_level *stl;
|
|
{
|
|
/* The identifier idf is inserted in the stack on level stl.
|
|
*/
|
|
register struct stack_entry *se = new_stack_entry();
|
|
|
|
/* link it into the stack level */
|
|
se->next = stl->sl_entry;
|
|
se->se_idf = idf;
|
|
stl->sl_entry = se;
|
|
}
|
|
|
|
struct stack_level *
|
|
stack_level_of(lvl)
|
|
{
|
|
/* The stack_level corresponding to level lvl is returned.
|
|
The stack should probably be an array, to be extended with
|
|
realloc where needed.
|
|
*/
|
|
register struct stack_level *stl;
|
|
|
|
if (lvl == level)
|
|
return local_level;
|
|
stl = &UniversalLevel;
|
|
|
|
while (stl->sl_level != lvl)
|
|
stl = stl->sl_next;
|
|
return stl;
|
|
}
|
|
|
|
unstack_level()
|
|
{
|
|
/* The top level of the identifier stack is removed.
|
|
*/
|
|
struct stack_level *lastlvl;
|
|
|
|
#ifdef DEBUG
|
|
if (options['t'])
|
|
dumpidftab("before unstackidfs", 0);
|
|
#endif /* DEBUG */
|
|
|
|
#ifdef LINT
|
|
lint_end_local(local_level);
|
|
#endif /* LINT */
|
|
|
|
/* The implementation below is more careful than strictly
|
|
necessary. Optimists may optimize it afterwards.
|
|
*/
|
|
while (local_level->sl_entry) {
|
|
register struct stack_entry *se = local_level->sl_entry;
|
|
register struct idf *idf = se->se_idf;
|
|
register struct def *def;
|
|
register struct sdef *sdef;
|
|
register struct tag *tag;
|
|
|
|
/* unlink it from the local stack level */
|
|
local_level->sl_entry = se->next;
|
|
free_stack_entry(se);
|
|
|
|
while ((def = idf->id_def) && def->df_level >= level) {
|
|
/* unlink it from the def list under the idf block */
|
|
if (def->df_sc == LABEL)
|
|
unstack_label(idf);
|
|
else if (def->df_sc == REGISTER || def->df_sc == AUTO)
|
|
FreeLocal(def->df_address);
|
|
idf->id_def = def->next;
|
|
free_def(def);
|
|
update_ahead(idf);
|
|
}
|
|
while ( (sdef = idf->id_sdef)
|
|
&& sdef->sd_level >= level
|
|
) {
|
|
/* unlink it from the sdef list under the idf block */
|
|
idf->id_sdef = sdef->next;
|
|
free_sdef(sdef);
|
|
}
|
|
while ( (tag = idf->id_struct)
|
|
&& tag->tg_level >= level
|
|
) {
|
|
/* unlink it from the struct list under the idf block */
|
|
idf->id_struct = tag->next;
|
|
free_tag(tag);
|
|
}
|
|
while ((tag = idf->id_enum) && tag->tg_level >= level) {
|
|
/* unlink it from the enum list under the idf block */
|
|
idf->id_enum = tag->next;
|
|
free_tag(tag);
|
|
}
|
|
}
|
|
/* Unlink the local stack level from the stack.
|
|
*/
|
|
lastlvl = local_level;
|
|
local_level = local_level->sl_previous;
|
|
if (level >= L_LOCAL) {
|
|
local_level->sl_max_block = lastlvl->sl_max_block;
|
|
}
|
|
free_stack_level(lastlvl);
|
|
local_level->sl_next = (struct stack_level *) 0;
|
|
level = local_level->sl_level;
|
|
|
|
#ifdef DEBUG
|
|
if (options['t'])
|
|
dumpidftab("after unstackidfs", 0);
|
|
#endif /* DEBUG */
|
|
}
|
|
|
|
unstack_world()
|
|
{
|
|
/* The global level of identifiers is scanned, and final
|
|
decisions are taken about such issues as
|
|
extern/static/global and un/initialized.
|
|
Effects on the code generator: initialised variables
|
|
have already been encoded while the uninitialised ones
|
|
are not and have to be encoded at this moment.
|
|
*/
|
|
register struct stack_entry *se = local_level->sl_entry;
|
|
|
|
#ifdef LINT
|
|
lint_end_global(local_level);
|
|
#endif /* LINT */
|
|
|
|
open_name_list();
|
|
|
|
while (se) {
|
|
register struct idf *idf = se->se_idf;
|
|
register struct def *def = idf->id_def;
|
|
|
|
if (!def) {
|
|
/* global selectors, etc. */
|
|
se = se->next;
|
|
continue;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
if (options['a']) {
|
|
char *symbol2str();
|
|
|
|
print("\"%s\", %s, %s, %s, %s\n",
|
|
idf->id_text,
|
|
(def->df_alloc == 0) ? "no alloc" :
|
|
(def->df_alloc == ALLOC_SEEN) ? "alloc seen" :
|
|
(def->df_alloc == ALLOC_DONE) ? "alloc done" :
|
|
"illegal alloc info",
|
|
symbol2str(def->df_sc),
|
|
def->df_initialized ? "init" : "no init",
|
|
def->df_used ? "used" : "not used");
|
|
}
|
|
#endif /* DEBUG */
|
|
/*
|
|
/_* find final storage class *_/
|
|
if (def->df_sc == GLOBAL || def->df_sc == IMPLICIT)
|
|
/_* even now we still don't know *_/
|
|
def->df_sc = EXTERN;
|
|
*/
|
|
|
|
if ( def->df_sc == STATIC
|
|
&& def->df_type->tp_fund == FUNCTION
|
|
&& !def->df_initialized
|
|
) {
|
|
/* orphaned static function */
|
|
#ifndef NOROPTION
|
|
if (options['R'])
|
|
warning("static function %s never defined, %s",
|
|
idf->id_text,
|
|
"changed to extern"
|
|
);
|
|
#endif
|
|
def->df_sc = EXTERN;
|
|
}
|
|
|
|
if (
|
|
def->df_alloc == ALLOC_SEEN &&
|
|
!def->df_initialized
|
|
) {
|
|
/* space must be allocated */
|
|
bss(idf);
|
|
if (def->df_sc != STATIC)
|
|
namelist(idf->id_text); /* may be common */
|
|
def->df_alloc = ALLOC_DONE; /* see Note below */
|
|
}
|
|
se = se->next;
|
|
}
|
|
/* Note:
|
|
df_alloc must be set to ALLOC_DONE because the idf entry
|
|
may occur several times in the list.
|
|
The reason for this is that the same name may be used
|
|
for different purposes on the same level, e.g.
|
|
struct s {int s;} s;
|
|
is a legal definition and contains 3 defining occurrences
|
|
of s.
|
|
Each definition has been entered into the identifier stack.
|
|
Although only one of them concerns a variable, we meet the
|
|
s 3 times when scanning the identifier stack.
|
|
*/
|
|
}
|
|
|
|
/* A list of potential common names is kept, to be fed to
|
|
an understanding loader. The list is written to a file
|
|
the name of which is nmlist. If nmlist == NULL, no name
|
|
list is generated.
|
|
*/
|
|
extern char *nmlist; /* BAH! -- main.c */
|
|
static File *nfp = 0;
|
|
|
|
open_name_list()
|
|
{
|
|
if (nmlist && sys_open(nmlist, OP_WRITE, &nfp) == 0)
|
|
fatal("cannot create namelist %s", nmlist);
|
|
}
|
|
|
|
namelist(nm)
|
|
char *nm;
|
|
{
|
|
if (nmlist) {
|
|
sys_write(nfp, nm, strlen(nm));
|
|
sys_write(nfp, "\n", 1);
|
|
}
|
|
}
|