ref: 022532e3e74a94ff9a194378c5a9f7a4904d82d3
dir: /cc1/symbol.c/
/* See LICENSE file for copyright and license details. */
static char sccsid[] = "@(#) ./cc1/symbol.c";
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <cstd.h>
#include "../inc/cc.h"
#include "cc1.h"
#define NR_SYM_HASH 64
#define NR_CPP_HASH 32
#define NR_LBL_HASH 16
unsigned curctx;
static unsigned short counterid;
static Symbol *head, *labels;
static Symbol *htab[NR_SYM_HASH];
static Symbol *htabcpp[NR_CPP_HASH];
static Symbol *htablbl[NR_LBL_HASH];
#ifndef NDEBUG
void
dumpstab(Symbol **tbl, char *msg)
{
Symbol **bp, *sym;
fprintf(stderr, "Symbol Table dump at ctx=%u\n%s\n", curctx, msg);
for (bp = tbl; bp < &tbl[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);
}
fputs("\nlabels:", stderr);
for (sym = labels; 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 Symbol **
hash(char *s, int ns)
{
unsigned c, h, size;
Symbol **tab;
for (h = 0; c = *s; ++s)
h = h*33 ^ c;
switch (ns) {
case NS_CPP:
tab = htabcpp;
size = NR_CPP_HASH-1;
break;
case NS_LABEL:
tab = htablbl;
size = NR_LBL_HASH-1;
break;
default:
tab = htab;
size = NR_SYM_HASH-1;
break;
}
return &tab[h & size];
}
static void
unlinkhash(Symbol *sym)
{
Symbol **h;
if ((sym->flags & SDECLARED) == 0)
return;
h = hash(sym->name, sym->ns);
assert(sym->ns == NS_CPP || *h == sym);
while (*h != sym)
h = &(*h)->hash;
*h = sym->hash;
}
void
pushctx(void)
{
DBG("SYM: pushed context %d", curctx+1);
if (++curctx == NR_BLOCK+1)
error("too many nested blocks");
}
void
killsym(Symbol *sym)
{
short f;
char *name;
if (!sym)
return;
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;
int ns, dangling = 0;
DBG("SYM: poped context %d", curctx);
/*
* we have to be careful before popping the current
* context, because since the parser is one token
* ahead it may already have read an identifier at
* this point, and yylval.sym is a pointer to
* the symbol associated to such token. If that
* symbol is from the context that we are popping
* then we are going to generate a dangling pointer.
* We can detect this situation and call again to
* lookup.
*/
if ((yytoken == IDEN || yytoken == TYPEIDEN) &&
yylval.sym->ctx == curctx) {
ns = yylval.sym->ns;
dangling = 1;
}
for (sym = head; sym && sym->ctx == curctx; sym = next) {
/*
* Since we are unlinking them in the inverse order
* we do know that sym is always the head of the
* collision list
*/
next = sym->next;
killsym(sym);
}
head = 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;
}
}
if (dangling) {
yylval.sym = lookup(ns, yytext, ALLOC);
yytoken = yylval.sym->token;
}
}
unsigned
newid(void)
{
unsigned short id;
if (lexmode == CPPMODE)
return 0;
id = ++counterid;
if (id == 0) {
die("Overflow in %s identifiers",
(curctx) ? "internal" : "external");
}
return id;
}
Symbol *
newsym(int ns, char *name)
{
Symbol *sym;
sym = xmalloc(sizeof(*sym));
if (name)
name = xstrdup(name);
sym->name = name;
sym->id = 0;
sym->hide = 0;
sym->ns = ns;
sym->ctx = curctx;
sym->token = IDEN;
sym->flags = 0;
sym->u.s = NULL;
sym->type = NULL;
sym->hash = NULL;
if (ns == NS_LABEL) {
sym->next = labels;
labels = sym;
} else if (ns != NS_CPP) {
sym->next = head;
head = sym;
}
return sym;
}
static Symbol *
linkhash(Symbol *sym)
{
Symbol **h;
h = hash(sym->name, sym->ns);
sym->hash = *h;
*h = sym;
if (sym->ns != NS_CPP)
sym->id = newid();
sym->flags |= SDECLARED;
return sym;
}
Symbol *
newstring(char *s, size_t len)
{
Symbol *sym = newsym(NS_IDEN, NULL);
if (lexmode != CPPMODE)
sym->type = mktype(chartype, ARY, len, NULL);
sym->id = newid();
sym->flags |= SSTRING | SCONSTANT | SPRIVATE;
sym->u.s = xmalloc(len);
if (s)
memcpy(sym->u.s, s, len);
return sym;
}
Symbol *
newlabel(void)
{
Symbol *sym = newsym(NS_LABEL, NULL);
sym->id = newid();
return sym;
}
Symbol *
lookup(int ns, char *name, int alloc)
{
Symbol *sym;
int sns;
char *t, c;
c = *name;
for (sym = *hash(name, ns); sym; sym = sym->hash) {
t = sym->name;
if (*t != c || strcmp(t, name))
continue;
sns = sym->ns;
if (sns == ns)
return sym;
/*
* 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.
* TODO: Remove this trick
*/
if (sns == NS_KEYWORD ||
(sym->flags & STYPEDEF) && ns >= NS_STRUCTS) {
return sym;
}
}
return (alloc == ALLOC) ? newsym(ns, name) : NULL;
}
Symbol *
install(int ns, Symbol *sym)
{
if (sym->flags & SDECLARED || sym->ctx != curctx) {
if (sym->ctx == curctx && ns == sym->ns)
return NULL;
sym = newsym(ns, sym->name);
}
return linkhash(sym);
}
void
keywords(struct keyword *key, int ns)
{
Symbol *sym;
for ( ; key->str; ++key) {
sym = linkhash(newsym(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;
}
void
builtins(struct builtin *built)
{
Symbol *sym;
struct builtin *bp;
for (bp = built; bp->str; ++bp) {
sym = linkhash(newsym(NS_KEYWORD, bp->str));
sym->token = BUILTIN;
sym->u.fun = bp->fun;
}
/*
* 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;
}