ref: 5eb497b0e16849c52bc45af5a7a5813c779da0e0
dir: /cc1/symbol.c/
/* See LICENSE file for copyright and license details. */
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../inc/cc.h"
#include "../inc/sizes.h"
#include "cc1.h"
#define NR_SYM_HASH 64
unsigned curctx;
static unsigned short counterid;
static Symbol *head, *labels;
static Symbol *htab[NR_SYM_HASH];
#ifndef NDEBUG
void
dumpstab(char *msg)
{
Symbol **bp, *sym;
fprintf(stderr, "Symbol Table dump at ctx=%u\n%s\n", curctx, msg);
for (bp = htab; bp < &htab[NR_SYM_HASH]; ++bp) {
if (*bp == NULL)
continue;
fprintf(stderr, "%d", (int) (bp - htab));
for (sym = *bp; sym; sym = sym->hash)
fprintf(stderr, "->[%d,%d:'%s'=%p]",
sym->ns, sym->ctx, sym->name, (void *) sym);
putc('\n', stderr);
}
fputs("head:", stderr);
for (sym = head; sym; sym = sym->next) {
fprintf(stderr, "->[%d,%d:'%s'=%p]",
sym->ns, sym->ctx,
(sym->name) ? sym->name : "", (void *) sym);
}
putc('\n', stderr);
}
#endif
static unsigned
hash(const char *s)
{
unsigned c, h;
for (h = 0; c = *s; ++s)
h ^= 33 * c;
return h & NR_SYM_HASH-1;
}
static void
unlinkhash(Symbol *sym)
{
Symbol **h, *p, *prev;
if ((sym->flags & SDECLARED) == 0)
return;
h = &htab[hash(sym->name)];
for (prev = p = *h; p != sym; prev = p, p = p->hash)
/* nothing */;
if (prev == p)
*h = sym->hash;
else
prev->hash = sym->hash;
}
void
pushctx(void)
{
if (++curctx == NR_BLOCK+1)
error("too many nested blocks");
}
void
killsym(Symbol *sym)
{
short f;
char *name;
f = sym->flags;
if (f & SSTRING)
free(sym->u.s);
if (sym->ns == NS_TAG)
sym->type->prop &= ~TDEFINED;
unlinkhash(sym);
if ((name = sym->name) != NULL && sym->ns != NS_CPP) {
if ((f & (SUSED|SGLOBAL|SDECLARED)) == SDECLARED)
warn("'%s' defined but not used", name);
if ((f & SDEFINED) == 0 && sym->ns == NS_LABEL)
errorp("label '%s' is not defined", name);
}
free(name);
free(sym);
}
void
popctx(void)
{
Symbol *next, *sym;
if (--curctx == GLOBALCTX) {
for (sym = labels; sym; sym = next) {
next = sym->next;
killsym(sym);
}
labels = NULL;
if (curfun) {
free(curfun->u.pars);
curfun->u.pars = NULL;
}
}
for (sym = head; sym && sym->ctx > curctx; sym = next) {
next = sym->next;
killsym(sym);
}
head = sym;
}
unsigned
newid(void)
{
unsigned short id;
id = ++counterid;
if (id == 0) {
die("Overflow in %s identifiers",
(curctx) ? "internal" : "external");
}
return id;
}
static Symbol *
allocsym(int ns, char *name)
{
Symbol *sym;
sym = xmalloc(sizeof(*sym));
if (name)
name = xstrdup(name);
sym->name = name;
sym->id = 0;
sym->ns = ns;
sym->ctx = (ns == NS_CPP) ? UCHAR_MAX : curctx;
sym->token = IDEN;
sym->flags = 0;
sym->u.s = NULL;
sym->type = NULL;
sym->next = sym->hash = NULL;
return sym;
}
static Symbol *
linksym(Symbol *sym)
{
Symbol *p, *prev;
switch (sym->ns) {
case NS_CPP:
return sym;
case NS_LABEL:
sym->next = labels;
return labels = sym;
default:
for (prev = p = head; p; prev = p, p = p->next) {
if (p->ctx <= sym->ctx)
break;
}
if (p == prev) {
sym->next = head;
head = sym;
} else {
p = prev->next;
prev->next = sym;
sym->next = p;
}
return sym;
}
}
static Symbol *
linkhash(Symbol *sym)
{
Symbol **h, *p, *prev;
h = &htab[hash(sym->name)];
for (prev = p = *h; p; prev = p, p = p->hash) {
if (p->ctx <= sym->ctx)
break;
}
if (p == prev) {
sym->hash = *h;
*h = sym;
} else {
p = prev->hash;
prev->hash = sym;
sym->hash = p;
}
if (sym->ns != NS_CPP)
sym->id = newid();
sym->flags |= SDECLARED;
return linksym(sym);
}
Symbol *
newsym(int ns)
{
return linksym(allocsym(ns, NULL));
}
Symbol *
newstring(char *s, size_t len)
{
Symbol *sym = newsym(NS_IDEN);
sym->id = newid();
sym->flags |= SSTRING | SCONSTANT | SPRIVATE;
sym->u.s = xmalloc(len);
if (s)
memcpy(sym->u.s, s, len);
sym->type = mktype(chartype, ARY, len, NULL);
return sym;
}
Symbol *
newlabel(void)
{
Symbol *sym = newsym(NS_LABEL);
sym->id = newid();
return sym;
}
Symbol *
lookup(int ns, char *name)
{
Symbol *sym;
int sns;
char *t, c;
c = *name;
for (sym = htab[hash(name)]; sym; sym = sym->hash) {
t = sym->name;
if (*t != c || strcmp(t, name))
continue;
sns = sym->ns;
/*
* CPP namespace has a total priority over the another
* namespaces, because it is a previous pass,
* If we are looking in the CPP namespace,
* we don't want symbols related to keywords or types.
* When a lookup is done in a namespace associated
* to a struct we also want symbols of NS_IDEN which
* are typedef, because in other case we cannot declare
* fields of such types.
*/
if (sns == NS_CPP && !disexpand || sns == ns)
return sym;
if (ns == NS_CPP)
continue;
if (sns == NS_KEYWORD ||
(sym->flags & STYPEDEF) && ns >= NS_STRUCTS) {
return sym;
}
}
return allocsym(ns, name);
}
Symbol *
nextsym(Symbol *sym, int ns)
{
char *s, *t, c;
Symbol *p;
/*
* This function is only called when a macro with parameters
* is called without them.
* #define x(y) ((y) + 1)
* int x = x(y);
*/
s = sym->name;
c = *s;
for (p = sym->hash; p; p = p->hash) {
t = p->name;
if (c == *t && !strcmp(s, t))
return p;
}
return allocsym(ns, s);
}
Symbol *
install(int ns, Symbol *sym)
{
if (sym->flags & SDECLARED) {
if (sym->ctx == curctx && ns == sym->ns)
return NULL;
sym = allocsym(ns, sym->name);
}
return linkhash(sym);
}
void
keywords(struct keyword *key, int ns)
{
Symbol *sym;
for ( ; key->str; ++key) {
sym = linkhash(allocsym(ns, key->str));
sym->token = key->token;
sym->u.token = key->value;
}
/*
* Remove all the predefined symbols from * the symbol list. It
* will make faster some operations. There is no problem of memory
* leakeage because this memory is not ever freed
*/
counterid = 0;
head = NULL;
}