An implementation of Unix dc and POSIX bc with GNU and BSD extensions. Finished, but well-maintained.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

230 lines
5.2 KiB

/*
* *****************************************************************************
*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2018-2021 Gavin D. Howard and contributors.
*
* 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 HOLDER 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 code for the lexers.
*
*/
#include <assert.h>
#include <ctype.h>
#include <stdbool.h>
#include <string.h>
#include <lex.h>
#include <vm.h>
#include <bc.h>
void bc_lex_invalidChar(BcLex *l, char c) {
l->t = BC_LEX_INVALID;
bc_lex_verr(l, BC_ERR_PARSE_CHAR, c);
}
void bc_lex_lineComment(BcLex *l) {
l->t = BC_LEX_WHITESPACE;
while (l->i < l->len && l->buf[l->i] != '\n') l->i += 1;
}
void bc_lex_comment(BcLex *l) {
size_t i, nlines = 0;
const char *buf = l->buf;
bool end = false;
char c;
l->i += 1;
l->t = BC_LEX_WHITESPACE;
for (i = l->i; !end; i += !end) {
for (; (c = buf[i]) && c != '*'; ++i) nlines += (c == '\n');
if (BC_ERR(!c || buf[i + 1] == '\0')) {
l->i = i;
bc_lex_err(l, BC_ERR_PARSE_COMMENT);
}
end = buf[i + 1] == '/';
}
l->i = i + 2;
l->line += nlines;
}
void bc_lex_whitespace(BcLex *l) {
char c;
l->t = BC_LEX_WHITESPACE;
for (c = l->buf[l->i]; c != '\n' && isspace(c); c = l->buf[++l->i]);
}
void bc_lex_commonTokens(BcLex *l, char c) {
if (!c) l->t = BC_LEX_EOF;
else if (c == '\n') l->t = BC_LEX_NLINE;
else bc_lex_whitespace(l);
}
static size_t bc_lex_num(BcLex *l, char start, bool int_only) {
const char *buf = l->buf + l->i;
size_t i;
char c;
bool last_pt, pt = (start == '.');
for (i = 0; (c = buf[i]) && (BC_LEX_NUM_CHAR(c, pt, int_only) ||
(c == '\\' && buf[i + 1] == '\n')); ++i)
{
if (c == '\\') {
if (buf[i + 1] == '\n') {
i += 2;
// Make sure to eat whitespace at the beginning of the line.
while(isspace(buf[i]) && buf[i] != '\n') i += 1;
c = buf[i];
if (!BC_LEX_NUM_CHAR(c, pt, int_only)) break;
}
else break;
}
last_pt = (c == '.');
if (pt && last_pt) break;
pt = pt || last_pt;
bc_vec_push(&l->str, &c);
}
return i;
}
void bc_lex_number(BcLex *l, char start) {
l->t = BC_LEX_NUMBER;
bc_vec_popAll(&l->str);
bc_vec_push(&l->str, &start);
l->i += bc_lex_num(l, start, false);
#if BC_ENABLE_EXTRA_MATH
{
char c = l->buf[l->i];
if (c == 'e') {
#if BC_ENABLED
if (BC_IS_POSIX) bc_lex_err(l, BC_ERR_POSIX_EXP_NUM);
#endif // BC_ENABLED
bc_vec_push(&l->str, &c);
l->i += 1;
c = l->buf[l->i];
if (c == BC_LEX_NEG_CHAR) {
bc_vec_push(&l->str, &c);
l->i += 1;
c = l->buf[l->i];
}
if (BC_ERR(!BC_LEX_NUM_CHAR(c, false, true)))
bc_lex_verr(l, BC_ERR_PARSE_CHAR, c);
l->i += bc_lex_num(l, 0, true);
}
}
#endif // BC_ENABLE_EXTRA_MATH
bc_vec_pushByte(&l->str, '\0');
}
void bc_lex_name(BcLex *l) {
size_t i = 0;
const char *buf = l->buf + l->i - 1;
char c = buf[i];
l->t = BC_LEX_NAME;
while ((c >= 'a' && c <= 'z') || isdigit(c) || c == '_') c = buf[++i];
bc_vec_string(&l->str, i, buf);
// Increment the index. We minus 1 because it has already been incremented.
l->i += i - 1;
}
void bc_lex_init(BcLex *l) {
BC_SIG_ASSERT_LOCKED;
assert(l != NULL);
bc_vec_init(&l->str, sizeof(char), NULL);
}
void bc_lex_free(BcLex *l) {
BC_SIG_ASSERT_LOCKED;
assert(l != NULL);
bc_vec_free(&l->str);
}
void bc_lex_file(BcLex *l, const char *file) {
assert(l != NULL && file != NULL);
l->line = 1;
vm.file = file;
}
void bc_lex_next(BcLex *l) {
assert(l != NULL);
l->last = l->t;
l->line += (l->i != 0 && l->buf[l->i - 1] == '\n');
if (BC_ERR(l->last == BC_LEX_EOF)) bc_lex_err(l, BC_ERR_PARSE_EOF);
l->t = BC_LEX_EOF;
if (l->i == l->len) return;
// Loop until failure or we don't have whitespace. This
// is so the parser doesn't get inundated with whitespace.
do {
vm.next(l);
} while (l->t == BC_LEX_WHITESPACE);
}
void bc_lex_text(BcLex *l, const char *text) {
assert(l != NULL && text != NULL);
l->buf = text;
l->i = 0;
l->len = strlen(text);
l->t = l->last = BC_LEX_INVALID;
bc_lex_next(l);
}