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Lua replace fscanf

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Rocklua was using the full fscanf implementation
to simply read %ld for the file:read("*n") function
wasting 1k on unneeded/unused functionality

Instead, I've implemented a filetol function to duplicate it
without the extra overhead using strtol which as an added bonus
ERANGE errors now resolve to LONG_MIN and LONGMAX instead of
integer overflow

filetol()
   reads long int from an open file, skips preceding
   whitespaces returns -1 if error, 1 on success.
   *num set to LONG_MAX or LONG_MIN on overflow.
   If number of digits is > than LUAI_MAXNUMBER2STR
   filepointer will continue till the next non digit
   but buffer will stop being filled with characters.
   Preceding zero is ignored.

Change-Id: Ia42d0f73c63a894625bca4581e9b7e1cc7387fd2
This commit is contained in:
William Wilgus 2018-10-29 02:54:35 -04:00
parent cc0a4c632a
commit eab73b3dee
6 changed files with 66 additions and 295 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
apps/plugins/lua/SOURCES
View file

@ -30,7 +30,6 @@ rockaux.c
rocklib.c
rocklib_img.c
tlsf_helper.c
fscanf.c
strftime.c
strpbrk.c
strtoul.c

291
apps/plugins/lua/fscanf.c
View file

@ -1,291 +0,0 @@
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copied from firmware/common/sscanf.c
* Original author: Tomasz Malesinski
*
* Copyright (C) 2010 Maurus Cuelenaere
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "rocklibc.h"
static int parse_dec(int (*peek)(void *userp),
void (*pop)(void *userp),
void *userp,
long *vp)
{
long v = 0;
int n = 0;
int minus = 0;
char ch;
if ((*peek)(userp) == '-')
{
(*pop)(userp);
n++;
minus = 1;
}
ch = (*peek)(userp);
if (!isdigit(ch))
return -1;
do
{
v = v * 10 + ch - '0';
(*pop)(userp);
n++;
ch = (*peek)(userp);
} while (isdigit(ch));
*vp = minus ? -v : v;
return n;
}
static int parse_chars(int (*peek)(void *userp),
void (*pop)(void *userp),
void *userp,
char *vp,
bool fake)
{
int n = 0;
char *pt=vp;
while (!isspace((*peek)(userp)))
{
if(fake==false)
*(pt++) = (*peek)(userp);
n++;
(*pop)(userp);
}
if(fake==false)
(*pt)='\0';
return n;
}
static int parse_hex(int (*peek)(void *userp),
void (*pop)(void *userp),
void *userp,
unsigned long *vp)
{
unsigned long v = 0;
int n = 0;
char ch;
ch = (*peek)(userp);
if (!isxdigit(ch))
return -1;
do
{
if (ch >= 'a')
ch = ch - 'a' + 10;
else if (ch >= 'A')
ch = ch - 'A' + 10;
else
ch = ch - '0';
v = v * 16 + ch;
(*pop)(userp);
n++;
ch = (*peek)(userp);
} while (isxdigit(ch));
*vp = v;
return n;
}
static int skip_spaces(int (*peek)(void *userp),
void (*pop)(void *userp),
void *userp)
{
int n = 0;
while (isspace((*peek)(userp))) {
n++;
(*pop)(userp);
}
return n;
}
static int scan(int (*peek)(void *userp),
void (*pop)(void *userp),
void *userp,
const char *fmt,
va_list ap)
{
char ch;
int n = 0;
int n_chars = 0;
int r;
long lval;
bool skip=false;
unsigned long ulval;
while ((ch = *fmt++) != '\0')
{
bool literal = false;
if (ch == '%')
{
ch = *fmt++;
if(ch== '*') /* We should process this, but not store it in an argument */
{
ch=*fmt++;
skip=true;
}
else
{
skip=false;
}
switch (ch)
{
case 'x':
n_chars += skip_spaces(peek, pop, userp);
if ((r = parse_hex(peek, pop, userp, &ulval)) >= 0)
{
if(skip==false)
{
*(va_arg(ap, unsigned int *)) = ulval;
n++;
}
n_chars += r;
}
else
return n;
break;
case 'd':
n_chars += skip_spaces(peek, pop, userp);
if ((r = parse_dec(peek, pop, userp, &lval)) >= 0)
{
if(skip==false)
{
*(va_arg(ap, int *)) = lval;
n++;
}
n_chars += r;
}
else
return n;
break;
case 'n':
if(skip==false)
{
*(va_arg(ap, int *)) = n_chars;
n++;
}
break;
case 'l':
n_chars += skip_spaces(peek, pop, userp);
ch = *fmt++;
switch (ch)
{
case 'x':
if ((r = parse_hex(peek, pop, userp, &ulval)) >= 0)
{
if(skip==false)
{
*(va_arg(ap, unsigned long *)) = ulval;
n++;
}
n_chars += r;
}
else
return n;
break;
case 'd':
if ((r = parse_dec(peek, pop, userp, &lval)) >= 0)
{
if(skip==false)
{
*(va_arg(ap, long *)) = lval;
n++;
}
n_chars += r;
}
else
return n;
break;
case '\0':
return n;
default:
literal = true;
break;
}
break;
case 's':
n_chars += skip_spaces(peek, pop, userp);
n_chars += parse_chars(peek,pop, userp,skip?0:va_arg(ap, char *), skip );
if(skip==false)
{
n++;
}
break;
case '\0':
return n;
default:
literal = true;
break;
}
} else
literal = true;
if (literal)
{
n_chars += skip_spaces(peek, pop, userp);
if ((*peek)(userp) != ch)
continue;
else
{
(*pop)(userp);
n_chars++;
}
}
}
return n;
}
static int fspeek(void *userp)
{
int fd = *((int*) userp);
char buf = 0;
if(rb->read(fd, &buf, 1) == 1)
rb->lseek(fd, -1, SEEK_CUR);
return buf;
}
static void fspop(void *userp)
{
int fd = *((int*) userp);
rb->lseek(fd, 1, SEEK_CUR);
}
int PREFIX(fscanf)(int fd, const char *fmt, ...)
{
int r;
va_list ap;
va_start(ap, fmt);
r = scan(fspeek, fspop, &fd, fmt, ap);
va_end(ap);
return r;
}

3
apps/plugins/lua/liolib.c
View file

@ -17,6 +17,7 @@
#include "lauxlib.h"
#include "lualib.h"
#include "rocklibc.h"
#include "rocklib.h"
#include "llimits.h"
@ -247,7 +248,7 @@ static int io_lines (lua_State *L) {
static int read_number (lua_State *L, int *f) {
lua_Number d;
if (PREFIX(fscanf)(*f, LUA_NUMBER_SCAN, &d) == 1) {
if (filetol(*f, &d) == 1) { /* was fscanf(f, LUA_NUMBER_SCAN, &d)*/
lua_pushnumber(L, d);
return 1;
}

63
apps/plugins/lua/rockaux.c
View file

@ -8,6 +8,7 @@
* $Id$
*
* Copyright (C) 2008 Dan Everton (safetydan)
* Copyright (C) 2018 William Wilgus
* String function implementations taken from dietlibc 0.31 (GPLv2 License)
*
* This program is free software; you can redistribute it and/or
@ -24,6 +25,8 @@
#define _ROCKCONF_H_ /* Protect against unwanted include */
#include "lua.h"
extern long strtol(const char *nptr, char **endptr, int base);
#if (CONFIG_PLATFORM & PLATFORM_NATIVE)
int errno = 0;
#endif
@ -101,3 +104,63 @@ int get_current_path(lua_State *L, int level)
lua_pushnil(L);
return 1;
}
/* filetol()
reads long int from an open file, skips preceding
whitespaces returns -1 if error, 1 on success.
*num set to LONG_MAX or LONG_MIN on overflow.
If number of digits is > than LUAI_MAXNUMBER2STR
filepointer will continue till the next non digit
but buffer will stop being filled with characters.
Preceding zero is ignored
*/
int filetol(int fd, long *num)
{
static char buffer[LUAI_MAXNUMBER2STR];
int retn = -1;
char chbuf = 0;
size_t count = 0;
bool neg = false;
long val;
while (rb->read(fd, &chbuf, 1) == 1)
{
if(!isspace(chbuf) || retn == 1)
{
if(chbuf == '0') /* strip preceeding zeros */
{
*num = 0;
retn = 1;
}
else if(chbuf == '-' && retn != 1)
neg = true;
else
{
rb->lseek(fd, -1, SEEK_CUR);
break;
}
}
}
while (rb->read(fd, &chbuf, 1) == 1)
{
if(!isdigit(chbuf))
{
rb->lseek(fd, -1, SEEK_CUR);
break;
}
else if (count < LUAI_MAXNUMBER2STR - 2)
buffer[count++] = chbuf;
}
if(count)
{
buffer[count] = '\0';
val = strtol(buffer, NULL, 10);
*num = (neg)? -val:val;
retn = 1;
}
return retn;
}

1
apps/plugins/lua/rocklib.h
View file

@ -47,6 +47,7 @@ struct lua_str_reg {
LUALIB_API int (luaopen_rock) (lua_State *L);
int get_current_path(lua_State *L, int level);
int filetol(int fd, long *num);
#endif /* _ROCKLIB_H_ */

2
apps/plugins/lua/rocklibc.h
View file

@ -43,7 +43,5 @@ extern int errno;
#define memcmp rb->memcmp
#define strlen rb->strlen
extern int PREFIX(fscanf)(int fd, const char *fmt, ...);
#endif /* _ROCKLIBC_H_ */