/*      $OpenBSD: look.c,v 1.24 2014/12/21 09:33:12 espie Exp $ */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ozan Yigit at York University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include <sys/cdefs.h>
/*
 * look.c
 * Facility: m4 macro processor
 * by: oz
 */

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <ohash.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"

static void *hash_calloc(size_t, size_t, void *);
static void hash_free(void *, void *);
static void *element_alloc(size_t, void *);
static void setup_definition(struct macro_definition *, const char *,
    const char *);
static void free_definition(char *);
static void keep(char *);
static int string_in_use(const char *);

static struct ohash_info macro_info = {
        offsetof(struct ndblock, name),
        NULL, hash_calloc, hash_free, element_alloc };

struct ohash macros;

/* Support routines for hash tables.  */
void *
hash_calloc(size_t n, size_t s, void *u __unused)
{
        void *storage = xcalloc(n, s, "hash alloc");
        return storage;
}

void
hash_free(void *p, void *u __unused)
{
        free(p);
}

void *
element_alloc(size_t s, void *u __unused)
{
        return xalloc(s, "element alloc");
}

void
init_macros(void)
{
        ohash_init(&macros, 10, &macro_info);
}

/*
 * find name in the hash table
 */
ndptr
lookup(const char *name)
{
        return ohash_find(&macros, ohash_qlookup(&macros, name));
}

struct macro_definition *
lookup_macro_definition(const char *name)
{
        ndptr p;

        p = ohash_find(&macros, ohash_qlookup(&macros, name));
        if (p)
                return p->d;
        else
                return NULL;
}

static void
setup_definition(struct macro_definition *d, const char *defn, const char *name)
{
        ndptr p;

        if (strncmp(defn, BUILTIN_MARKER, sizeof(BUILTIN_MARKER)-1) == 0 &&
            (p = macro_getbuiltin(defn+sizeof(BUILTIN_MARKER)-1)) != NULL) {
                d->type = macro_builtin_type(p);
                d->defn = xstrdup(defn+sizeof(BUILTIN_MARKER)-1);
        } else {
                if (!*defn)
                        d->defn = __DECONST(char *, null);
                else
                        d->defn = xstrdup(defn);
                d->type = MACROTYPE;
        }
        if (STREQ(name, defn))
                d->type |= RECDEF;
}

static ndptr
create_entry(const char *name)
{
        const char *end = NULL;
        ndptr n;
        unsigned int i;

        i = ohash_qlookupi(&macros, name, &end);
        n = ohash_find(&macros, i);
        if (n == NULL) {
                n = ohash_create_entry(&macro_info, name, &end);
                ohash_insert(&macros, i, n);
                n->trace_flags = FLAG_NO_TRACE;
                n->builtin_type = MACROTYPE;
                n->d = NULL;
        }
        return n;
}

void
macro_define(const char *name, const char *defn)
{
        ndptr n = create_entry(name);

        if (n->d != NULL) {
                if (n->d->defn != null)
                        free_definition(n->d->defn);
        } else {
                n->d = xalloc(sizeof(struct macro_definition), NULL);
                n->d->next = NULL;
        }
        setup_definition(n->d, defn, name);
}

void
macro_pushdef(const char *name, const char *defn)
{
        ndptr n;
        struct macro_definition *d;

        n = create_entry(name);
        d = xalloc(sizeof(struct macro_definition), NULL);
        d->next = n->d;
        n->d = d;
        setup_definition(n->d, defn, name);
}

void
macro_undefine(const char *name)
{
        ndptr n = lookup(name);

        if (n != NULL) {
                struct macro_definition *r, *r2;

                for (r = n->d; r != NULL; r = r2) {
                        r2 = r->next;
                        if (r->defn != null)
                                free(r->defn);
                        free(r);
                }
                n->d = NULL;
        }
}

void
macro_popdef(const char *name)
{
        ndptr n = lookup(name);

        if (n != NULL) {
                struct macro_definition *r = n->d;
                if (r != NULL) {
                        n->d = r->next;
                        if (r->defn != null)
                                free(r->defn);
                        free(r);
                }
        }
}

void
macro_for_all(void (*f)(const char *, struct macro_definition *))
{
        ndptr n;
        unsigned int i;

        for (n = ohash_first(&macros, &i); n != NULL;
            n = ohash_next(&macros, &i))
                if (n->d != NULL)
                        f(n->name, n->d);
}

void
setup_builtin(const char *name, unsigned int type)
{
        ndptr n;
        char *name2;

        if (prefix_builtins) {
                name2 = xalloc(strlen(name)+3+1, NULL);
                memcpy(name2, "m4_", 3);
                memcpy(name2 + 3, name, strlen(name)+1);
        } else
                name2 = xstrdup(name);

        n = create_entry(name2);
        n->builtin_type = type;
        n->d = xalloc(sizeof(struct macro_definition), NULL);
        n->d->defn = name2;
        n->d->type = type;
        n->d->next = NULL;
}

void
mark_traced(const char *name, int on)
{
        ndptr p;
        unsigned int i;

        if (name == NULL) {
                if (on)
                        trace_flags |= TRACE_ALL;
                else
                        trace_flags &= ~TRACE_ALL;
                for (p = ohash_first(&macros, &i); p != NULL;
                    p = ohash_next(&macros, &i))
                        p->trace_flags = FLAG_NO_TRACE;
        } else {
                p = create_entry(name);
                p->trace_flags = on;
        }
}

ndptr
macro_getbuiltin(const char *name)
{
        ndptr p;

        p = lookup(name);
        if (p == NULL || p->builtin_type == MACROTYPE)
                return NULL;
        else
                return p;
}

/* XXX things are slightly more complicated than they seem.
 * a macro may actually be "live" (in the middle of an expansion
 * on the stack.
 * So we actually may need to place it in an array for later...
 */

static int kept_capacity = 0;
static int kept_size = 0;
static char **kept = NULL;

static void
keep(char *ptr)
{
        if (kept_capacity <= kept_size) {
                if (kept_capacity)
                        kept_capacity *= 2;
                else
                        kept_capacity = 50;
                kept = xreallocarray(kept, kept_capacity,
                    sizeof(char *), "Out of memory while saving %d strings\n",
                    kept_capacity);
        }
        kept[kept_size++] = ptr;
}

static int
string_in_use(const char *ptr)
{
        int i;

        for (i = 0; i <= sp; i++)
                if (sstack[i] == STORAGE_MACRO && mstack[i].sstr == ptr)
                        return 1;
        return 0;
}


static void
free_definition(char *ptr)
{
        int i;

        /* first try to free old strings */
        for (i = 0; i < kept_size; i++) {
                if (!string_in_use(kept[i])) {
                        kept_size--;
                        free(kept[i]);
                        if (i != kept_size)
                                kept[i] = kept[kept_size];
                        i--;
                }
        }

        /* then deal with us */
        if (string_in_use(ptr))
                keep(ptr);
        else
                free(ptr);
}