nasm/output/strtbl.c
H. Peter Anvin bbb39579ec hashtbl, strtbl: add hash_free_all(), split strtbl_find()
Add hash_free_all() to factor common code of iterating over all
members of a hash to free them with a single nasm_free().

Split strtbl_find() into strtbl_find() and strtbl_add().  It is very
unlikely that the same call site will want to have both of these
functionalities, and in the end the code for the two functions are
surprisingly different.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2017-04-24 00:54:51 -07:00

118 lines
3.5 KiB
C

/* ----------------------------------------------------------------------- *
*
* Copyright 2017 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*
* ----------------------------------------------------------------------- */
/*
* Common string table handling
*
* A number of output formats use a "string table"; a container for
* a number of strings which may be reused at will. This implements
* a string table which eliminates duplicates and returns the index
* into the string table when queried.
*/
#include "compiler.h"
#include "nasm.h"
#include "nasmlib.h"
#include "error.h"
#include "strtbl.h"
struct strtbl_entry {
size_t index;
size_t bytes;
char str[1];
};
void strtbl_init(struct nasm_strtbl *tbl)
{
tbl->size = 0;
hash_init(&tbl->hash, HASH_LARGE);
strtbl_add(tbl, ""); /* Index 0 is always an empty string */
}
void strtbl_free(struct nasm_strtbl *tbl)
{
hash_free_all(&tbl->hash, false);
}
size_t strtbl_add(struct nasm_strtbl *tbl, const char *str)
{
void **sep;
struct strtbl_entry *se;
struct hash_insert hi;
sep = hash_find(&tbl->hash, str, &hi);
if (sep) {
se = *sep;
} else {
size_t bytes = strlen(str) + 1;
se = nasm_malloc(sizeof(struct strtbl_entry)-1+bytes);
se->index = tbl->size;
tbl->size += bytes;
se->bytes = bytes;
memcpy(se->str, str, bytes);
hash_add(&hi, se->str, se);
}
return se->index;
}
size_t strtbl_find(struct nasm_strtbl *tbl, const char *str)
{
void **sep;
struct strtbl_entry *se;
sep = hash_find(&tbl->hash, str, NULL);
if (sep) {
se = *sep;
return se->index;
} else {
return STRTBL_NONE;
}
}
/* This create a linearized buffer containing the actual string table */
void *strtbl_generate(const struct nasm_strtbl *tbl)
{
char *buf = nasm_malloc(strtbl_size(tbl));
struct hash_tbl_node *iter = NULL;
struct strtbl_entry *se;
while ((se = hash_iterate(&tbl->hash, &iter, NULL)))
memcpy(buf + se->index, se->str, se->bytes);
return buf;
}