nasm/stdscan.c
H. Peter Anvin 2ef4aac272 Allow underscores in numbers; better detection of FP
- Allow underscores as group separators in numbers, for example:
  0x1234_5678 is now a legal number.  The underscore is just ignored,
  it adds no meaning.
- Recognize dotless floating-point numbers, such as "1e30".  This
  entails distinguishing hexadecimal numbers in the scanner, since
  e.g. 0x1e30 is a perfectly legitimate hex constant.
2007-10-19 13:10:46 -07:00

212 lines
6.9 KiB
C

#include "compiler.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <inttypes.h>
#include "nasm.h"
#include "nasmlib.h"
#include "stdscan.h"
#include "insns.h"
/*
* Standard scanner routine used by parser.c and some output
* formats. It keeps a succession of temporary-storage strings in
* stdscan_tempstorage, which can be cleared using stdscan_reset.
*/
static char **stdscan_tempstorage = NULL;
static int stdscan_tempsize = 0, stdscan_templen = 0;
#define STDSCAN_TEMP_DELTA 256
static void stdscan_pop(void)
{
nasm_free(stdscan_tempstorage[--stdscan_templen]);
}
void stdscan_reset(void)
{
while (stdscan_templen > 0)
stdscan_pop();
}
/*
* Unimportant cleanup is done to avoid confusing people who are trying
* to debug real memory leaks
*/
void stdscan_cleanup(void)
{
stdscan_reset();
nasm_free(stdscan_tempstorage);
}
static char *stdscan_copy(char *p, int len)
{
char *text;
text = nasm_malloc(len + 1);
strncpy(text, p, len);
text[len] = '\0';
if (stdscan_templen >= stdscan_tempsize) {
stdscan_tempsize += STDSCAN_TEMP_DELTA;
stdscan_tempstorage = nasm_realloc(stdscan_tempstorage,
stdscan_tempsize *
sizeof(char *));
}
stdscan_tempstorage[stdscan_templen++] = text;
return text;
}
char *stdscan_bufptr = NULL;
int stdscan(void *private_data, struct tokenval *tv)
{
char ourcopy[MAX_KEYWORD + 1], *r, *s;
(void)private_data; /* Don't warn that this parameter is unused */
while (isspace(*stdscan_bufptr))
stdscan_bufptr++;
if (!*stdscan_bufptr)
return tv->t_type = 0;
/* we have a token; either an id, a number or a char */
if (isidstart(*stdscan_bufptr) ||
(*stdscan_bufptr == '$' && isidstart(stdscan_bufptr[1]))) {
/* now we've got an identifier */
bool is_sym = false;
if (*stdscan_bufptr == '$') {
is_sym = true;
stdscan_bufptr++;
}
r = stdscan_bufptr++;
/* read the entire buffer to advance the buffer pointer but... */
while (isidchar(*stdscan_bufptr))
stdscan_bufptr++;
/* ... copy only up to IDLEN_MAX-1 characters */
tv->t_charptr = stdscan_copy(r, stdscan_bufptr - r < IDLEN_MAX ?
stdscan_bufptr - r : IDLEN_MAX - 1);
if (is_sym || stdscan_bufptr - r > MAX_KEYWORD)
return tv->t_type = TOKEN_ID; /* bypass all other checks */
for (s = tv->t_charptr, r = ourcopy; *s; s++)
*r++ = tolower(*s);
*r = '\0';
/* right, so we have an identifier sitting in temp storage. now,
* is it actually a register or instruction name, or what? */
return nasm_token_hash(ourcopy, tv);
} else if (*stdscan_bufptr == '$' && !isnumchar(stdscan_bufptr[1])) {
/*
* It's a $ sign with no following hex number; this must
* mean it's a Here token ($), evaluating to the current
* assembly location, or a Base token ($$), evaluating to
* the base of the current segment.
*/
stdscan_bufptr++;
if (*stdscan_bufptr == '$') {
stdscan_bufptr++;
return tv->t_type = TOKEN_BASE;
}
return tv->t_type = TOKEN_HERE;
} else if (isnumstart(*stdscan_bufptr)) { /* now we've got a number */
bool rn_error;
bool is_hex = false;
bool is_float = false;
char c;
r = stdscan_bufptr++;
if (r[0] == '$' || (r[0] == '0' || (r[1] == 'x' || r[1] == 'X')))
is_hex = true;
for (;;) {
c = *stdscan_bufptr++;
if ((!is_hex && (c == 'e' || c == 'E')) ||
(c == 'P' || c == 'p')) {
is_float = true;
if (*stdscan_bufptr == '+' || *stdscan_bufptr == '-')
stdscan_bufptr++;
} else if (isnumchar(c) || c == '_')
; /* just advance */
else if (c == '.')
is_float = true;
else
break;
}
stdscan_bufptr--; /* Point to first character beyond number */
if (is_float) {
tv->t_charptr = stdscan_copy(r, stdscan_bufptr - r);
return tv->t_type = TOKEN_FLOAT;
} else {
r = stdscan_copy(r, stdscan_bufptr - r);
tv->t_integer = readnum(r, &rn_error);
stdscan_pop();
if (rn_error)
return tv->t_type = TOKEN_ERRNUM; /* some malformation occurred */
tv->t_charptr = NULL;
return tv->t_type = TOKEN_NUM;
}
} else if (*stdscan_bufptr == '\'' || *stdscan_bufptr == '"') { /* a char constant */
char quote = *stdscan_bufptr++, *r;
bool rn_warn;
r = tv->t_charptr = stdscan_bufptr;
while (*stdscan_bufptr && *stdscan_bufptr != quote)
stdscan_bufptr++;
tv->t_inttwo = stdscan_bufptr - r; /* store full version */
if (!*stdscan_bufptr)
return tv->t_type = TOKEN_ERRNUM; /* unmatched quotes */
stdscan_bufptr++; /* skip over final quote */
tv->t_integer = readstrnum(r, tv->t_inttwo, &rn_warn);
/* FIXME: rn_warn is not checked! */
return tv->t_type = TOKEN_NUM;
} else if (*stdscan_bufptr == ';') { /* a comment has happened - stay */
return tv->t_type = 0;
} else if (stdscan_bufptr[0] == '>' && stdscan_bufptr[1] == '>') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_SHR;
} else if (stdscan_bufptr[0] == '<' && stdscan_bufptr[1] == '<') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_SHL;
} else if (stdscan_bufptr[0] == '/' && stdscan_bufptr[1] == '/') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_SDIV;
} else if (stdscan_bufptr[0] == '%' && stdscan_bufptr[1] == '%') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_SMOD;
} else if (stdscan_bufptr[0] == '=' && stdscan_bufptr[1] == '=') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_EQ;
} else if (stdscan_bufptr[0] == '<' && stdscan_bufptr[1] == '>') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_NE;
} else if (stdscan_bufptr[0] == '!' && stdscan_bufptr[1] == '=') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_NE;
} else if (stdscan_bufptr[0] == '<' && stdscan_bufptr[1] == '=') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_LE;
} else if (stdscan_bufptr[0] == '>' && stdscan_bufptr[1] == '=') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_GE;
} else if (stdscan_bufptr[0] == '&' && stdscan_bufptr[1] == '&') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_DBL_AND;
} else if (stdscan_bufptr[0] == '^' && stdscan_bufptr[1] == '^') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_DBL_XOR;
} else if (stdscan_bufptr[0] == '|' && stdscan_bufptr[1] == '|') {
stdscan_bufptr += 2;
return tv->t_type = TOKEN_DBL_OR;
} else /* just an ordinary char */
return tv->t_type = (uint8_t)(*stdscan_bufptr++);
}