/*
** String library.
** Copyright (C) 2005-2022 Mike Pall. See Copyright Notice in luajit.h
**
** Major portions taken verbatim or adapted from the Lua interpreter.
** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
*/
#define lib_string_c
#define LUA_LIB
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
#include "lj_obj.h"
#include "lj_gc.h"
#include "lj_err.h"
#include "lj_buf.h"
#include "lj_str.h"
#include "lj_tab.h"
#include "lj_meta.h"
#include "lj_state.h"
#include "lj_ff.h"
#include "lj_bcdump.h"
#include "lj_char.h"
#include "lj_strfmt.h"
#include "lj_lib.h"
/* ------------------------------------------------------------------------ */
#define LJLIB_MODULE_string
LJLIB_LUA(string_len) /*
function(s)
CHECK_str(s)
return #s
end
*/
LJLIB_ASM(string_byte) LJLIB_REC(string_range 0)
{
GCstr *s = lj_lib_checkstr(L, 1);
int32_t len = (int32_t)s->len;
int32_t start = lj_lib_optint(L, 2, 1);
int32_t stop = lj_lib_optint(L, 3, start);
int32_t n, i;
const unsigned char *p;
if (stop < 0) stop += len+1;
if (start < 0) start += len+1;
if (start <= 0) start = 1;
if (stop > len) stop = len;
if (start > stop) return FFH_RES(0); /* Empty interval: return no results. */
start--;
n = stop - start;
if ((uint32_t)n > LUAI_MAXCSTACK)
lj_err_caller(L, LJ_ERR_STRSLC);
lj_state_checkstack(L, (MSize)n);
p = (const unsigned char *)strdata(s) + start;
for (i = 0; i < n; i++)
setintV(L->base + i-1-LJ_FR2, p[i]);
return FFH_RES(n);
}
LJLIB_ASM(string_char) LJLIB_REC(.)
{
int i, nargs = (int)(L->top - L->base);
char *buf = lj_buf_tmp(L, (MSize)nargs);
for (i = 1; i <= nargs; i++) {
int32_t k = lj_lib_checkint(L, i);
if (!checku8(k))
lj_err_arg(L, i, LJ_ERR_BADVAL);
buf[i-1] = (char)k;
}
setstrV(L, L->base-1-LJ_FR2, lj_str_new(L, buf, (size_t)nargs));
return FFH_RES(1);
}
LJLIB_ASM(string_sub) LJLIB_REC(string_range 1)
{
lj_lib_checkstr(L, 1);
lj_lib_checkint(L, 2);
setintV(L->base+2, lj_lib_optint(L, 3, -1));
return FFH_RETRY;
}
LJLIB_CF(string_rep) LJLIB_REC(.)
{
GCstr *s = lj_lib_checkstr(L, 1);
int32_t rep = lj_lib_checkint(L, 2);
GCstr *sep = lj_lib_optstr(L, 3);
SBuf *sb = lj_buf_tmp_(L);
if (sep && rep > 1) {
GCstr *s2 = lj_buf_cat2str(L, sep, s);
lj_buf_reset(sb);
lj_buf_putstr(sb, s);
s = s2;
rep--;
}
sb = lj_buf_putstr_rep(sb, s, rep);
setstrV(L, L->top-1, lj_buf_str(L, sb));
lj_gc_check(L);
return 1;
}
LJLIB_ASM(string_reverse) LJLIB_REC(string_op IRCALL_lj_buf_putstr_reverse)
{
lj_lib_checkstr(L, 1);
return FFH_RETRY;
}
LJLIB_ASM_(string_lower) LJLIB_REC(string_op IRCALL_lj_buf_putstr_lower)
LJLIB_ASM_(string_upper) LJLIB_REC(string_op IRCALL_lj_buf_putstr_upper)
/* ------------------------------------------------------------------------ */
static int writer_buf(lua_State *L, const void *p, size_t size, void *sb)
{
lj_buf_putmem((SBuf *)sb, p, (MSize)size);
UNUSED(L);
return 0;
}
LJLIB_CF(string_dump)
{
GCfunc *fn = lj_lib_checkfunc(L, 1);
int strip = L->base+1 < L->top && tvistruecond(L->base+1);
SBuf *sb = lj_buf_tmp_(L); /* Assumes lj_bcwrite() doesn't use tmpbuf. */
L->top = L->base+1;
if (!isluafunc(fn) || lj_bcwrite(L, funcproto(fn), writer_buf, sb, strip))
lj_err_caller(L, LJ_ERR_STRDUMP);
setstrV(L, L->top-1, lj_buf_str(L, sb));
lj_gc_check(L);
return 1;
}
/* ------------------------------------------------------------------------ */
/* macro to `unsign' a character */
#define uchar(c) ((unsigned char)(c))
#define CAP_UNFINISHED (-1)
#define CAP_POSITION (-2)
typedef struct MatchState {
const char *src_init; /* init of source string */
const char *src_end; /* end (`\0') of source string */
lua_State *L;
int level; /* total number of captures (finished or unfinished) */
int depth;
struct {
const char *init;
ptrdiff_t len;
} capture[LUA_MAXCAPTURES];
} MatchState;
#define L_ESC '%'
static int check_capture(MatchState *ms, int l)
{
l -= '1';
if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
lj_err_caller(ms->L, LJ_ERR_STRCAPI);
return l;
}
static int capture_to_close(MatchState *ms)
{
int level = ms->level;
for (level--; level>=0; level--)
if (ms->capture[level].len == CAP_UNFINISHED) return level;
lj_err_caller(ms->L, LJ_ERR_STRPATC);
return 0; /* unreachable */
}
static const char *classend(MatchState *ms, const char *p)
{
switch (*p++) {
case L_ESC:
if (*p == '\0')
lj_err_caller(ms->L, LJ_ERR_STRPATE);
return p+1;
case '[':
if (*p == '^') p++;
do { /* look for a `]' */
if (*p == '\0')
lj_err_caller(ms->L, LJ_ERR_STRPATM);
if (*(p++) == L_ESC && *p != '\0')
p++; /* skip escapes (e.g. `%]') */
} while (*p != ']');
return p+1;
default:
return p;
}
}
static const unsigned char match_class_map[32] = {
0,LJ_CHAR_ALPHA,0,LJ_CHAR_CNTRL,LJ_CHAR_DIGIT,0,0,LJ_CHAR_GRAPH,0,0,0,0,
LJ_CHAR_LOWER,0,0,0,LJ_CHAR_PUNCT,0,0,LJ_CHAR_SPACE,0,
LJ_CHAR_UPPER,0,LJ_CHAR_ALNUM,LJ_CHAR_XDIGIT,0,0,0,0,0,0,0
};
static int match_class(int c, int cl)
{
if ((cl & 0xc0) == 0x40) {
int t = match_class_map[(cl&0x1f)];
if (t) {
t = lj_char_isa(c, t);
return (cl & 0x20) ? t : !t;
}
if (cl == 'z') return c == 0;
if (cl == 'Z') return c != 0;
}
return (cl == c);
}
static int matchbracketclass(int c, const char *p, const char *ec)
{
int sig = 1;
if (*(p+1) == '^') {
sig = 0;
p++; /* skip the `^' */
}
while (++p < ec) {
if (*p == L_ESC) {
p++;
if (match_class(c, uchar(*p)))
return sig;
}
else if ((*(p+1) == '-') && (p+2 < ec)) {
p+=2;
if (uchar(*(p-2)) <= c && c <= uchar(*p))
return sig;
}
else if (uchar(*p) == c) return sig;
}
return !sig;
}
static int singlematch(int c, const char *p, const char *ep)
{
switch (*p) {
case '.': return 1; /* matches any char */
case L_ESC: return match_class(c, uchar(*(p+1)));
case '[': return matchbracketclass(c, p, ep-1);
default: return (uchar(*p) == c);
}
}
static const char *match(MatchState *ms, const char *s, const char *p);
static const char *matchbalance(MatchState *ms, const char *s, const char *p)
{
if (*p == 0 || *(p+1) == 0)
lj_err_caller(ms->L, LJ_ERR_STRPATU);
if (*s != *p) {
return NULL;
} else {
int b = *p;
int e = *(p+1);
int cont = 1;
while (++s < ms->src_end) {
if (*s == e) {
if (--cont == 0) return s+1;
} else if (*s == b) {
cont++;
}
}
}
return NULL; /* string ends out of balance */
}
static const char *max_expand(MatchState *ms, const char *s,
const char *p, const char *ep)
{
ptrdiff_t i = 0; /* counts maximum expand for item */
while ((s+i)<ms->src_end && singlematch(uchar(*(s+i)), p, ep))
i++;
/* keeps trying to match with the maximum repetitions */
while (i>=0) {
const char *res = match(ms, (s+i), ep+1);
if (res) return res;
i--; /* else didn't match; reduce 1 repetition to try again */
}
return NULL;
}
static const char *min_expand(MatchState *ms, const char *s,
const char *p, const char *ep)
{
for (;;) {
const char *res = match(ms, s, ep+1);
if (res != NULL)
return res;
else if (s<ms->src_end && singlematch(uchar(*s), p, ep))
s++; /* try with one more repetition */
else
return NULL;
}
}
static const char *start_capture(MatchState *ms, const char *s,
const char *p, int what)
{
const char *res;
int level = ms->level;
if (level >= LUA_MAXCAPTURES) lj_err_caller(ms->L, LJ_ERR_STRCAPN);
ms->capture[level].init = s;
ms->capture[level].len = what;
ms->level = level+1;
if ((res=match(ms, s, p)) == NULL) /* match failed? */
ms->level--; /* undo capture */
return res;
}
static const char *end_capture(MatchState *ms, const char *s,
const char *p)
{
int l = capture_to_close(ms);
const char *res;
ms->capture[l].len = s - ms->capture[l].init; /* close capture */
if ((res = match(ms, s, p)) == NULL) /* match failed? */
ms->capture[l].len = CAP_UNFINISHED; /* undo capture */
return res;
}
static const char *match_capture(MatchState *ms, const char *s, int l)
{
size_t len;
l = check_capture(ms, l);
len = (size_t)ms->capture[l].len;
if ((size_t)(ms->src_end-s) >= len &&
memcmp(ms->capture[l].init, s, len) == 0)
return s+len;
else
return NULL;
}
static const char *match(MatchState *ms, const char *s, const char *p)
{
if (++ms->depth > LJ_MAX_XLEVEL)
lj_err_caller(ms->L, LJ_ERR_STRPATX);
init: /* using goto's to optimize tail recursion */
switch (*p) {
case '(': /* start capture */
if (*(p+1) == ')') /* position capture? */
s = start_capture(ms, s, p+2, CAP_POSITION);
else
s = start_capture(ms, s, p+1, CAP_UNFINISHED);
break;
case ')': /* end capture */
s = end_capture(ms, s, p+1);
break;
case L_ESC:
switch (*(p+1)) {
case 'b': /* balanced string? */
s = matchbalance(ms, s, p+2);
if (s == NULL) break;
p+=4;
goto init; /* else s = match(ms, s, p+4); */
case 'f': { /* frontier? */
const char *ep; char previous;
p += 2;
if (*p != '[')
lj_err_caller(ms->L, LJ_ERR_STRPATB);
ep = classend(ms, p); /* points to what is next */
previous = (s == ms->src_init) ? '\0' : *(s-1);
if (matchbracketclass(uchar(previous), p, ep-1) ||
!matchbracketclass(uchar(*s), p, ep-1)) { s = NULL; break; }
p=ep;
goto init; /* else s = match(ms, s, ep); */
}
default:
if (lj_char_isdigit(uchar(*(p+1)))) { /* capture results (%0-%9)? */
s = match_capture(ms, s, uchar(*(p+1)));
if (s == NULL) break;
p+=2;
goto init; /* else s = match(ms, s, p+2) */
}
goto dflt; /* case default */
}
break;
case '\0': /* end of pattern */
break; /* match succeeded */
case '$':
/* is the `$' the last char in pattern? */
if (*(p+1) != '\0') goto dflt;
if (s != ms->src_end) s = NULL; /* check end of string */
break;
default: dflt: { /* it is a pattern item */
const char *ep = classend(ms, p); /* points to what is next */
int m = s<ms->src_end && singlematch(uchar(*s), p, ep);
switch (*ep) {
case '?': { /* optional */
const char *res;
if (m && ((res=match(ms, s+1, ep+1)) != NULL)) {
s = res;
break;
}
p=ep+1;
goto init; /* else s = match(ms, s, ep+1); */
}
case '*': /* 0 or more repetitions */
s = max_expand(ms, s, p, ep);
break;
case '+': /* 1 or more repetitions */
s = (m ? max_expand(ms, s+1, p, ep) : NULL);
break;
case '-': /* 0 or more repetitions (minimum) */
s = min_expand(ms, s, p, ep);
break;
default:
if (m) { s++; p=ep; goto init; } /* else s = match(ms, s+1, ep); */
s = NULL;
break;
}
break;
}
}
ms->depth--;
return s;
}
static void push_onecapture(MatchState *ms, int i, const char *s, const char *e)
{
if (i >= ms->level) {
if (i == 0) /* ms->level == 0, too */
lua_pushlstring(ms->L, s, (size_t)(e - s)); /* add whole match */
else
lj_err_caller(ms->L, LJ_ERR_STRCAPI);
} else {
ptrdiff_t l = ms->capture[i].len;
if (l == CAP_UNFINISHED) lj_err_caller(ms->L, LJ_ERR_STRCAPU);
if (l == CAP_POSITION)
lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1);
else
lua_pushlstring(ms->L, ms->capture[i].init, (size_t)l);
}
}
static int push_captures(MatchState *ms, const char *s, const char *e)
{
int i;
int nlevels = (ms->level == 0 && s) ? 1 : ms->level;
luaL_checkstack(ms->L, nlevels, "too many captures");
for (i = 0; i < nlevels; i++)
push_onecapture(ms, i, s, e);
return nlevels; /* number of strings pushed */
}
static int str_find_aux(lua_State *L, int find)
{
GCstr *s = lj_lib_checkstr(L, 1);
GCstr *p = lj_lib_checkstr(L, 2);
int32_t start = lj_lib_optint(L, 3, 1);
MSize st;
if (start < 0) start += (int32_t)s->len; else start--;
if (start < 0) start = 0;
st = (MSize)start;
if (st > s->len) {
#if LJ_52
setnilV(L->top-1);
return 1;
#else
st = s->len;
#endif
}
if (find && ((L->base+3 < L->top && tvistruecond(L->base+3)) ||
!lj_str_haspattern(p))) { /* Search for fixed string. */
const char *q = lj_str_find(strdata(s)+st, strdata(p), s->len-st, p->len);
if (q) {
setintV(L->top-2, (int32_t)(q-strdata(s)) + 1);
setintV(L->top-1, (int32_t)(q-strdata(s)) + (int32_t)p->len);
return 2;
}
} else { /* Search for pattern. */
MatchState ms;
const char *pstr = strdata(p);
const char *sstr = strdata(s) + st;
int anchor = 0;
if (*pstr == '^') { pstr++; anchor = 1; }
ms.L = L;
ms.src_init = strdata(s);
ms.src_end = strdata(s) + s->len;
do { /* Loop through string and try to match the pattern. */
const char *q;
ms.level = ms.depth = 0;
q = match(&ms, sstr, pstr);
if (q) {
if (find) {
setintV(L->top++, (int32_t)(sstr-(strdata(s)-1)));
setintV(L->top++, (int32_t)(q-strdata(s)));
return push_captures(&ms, NULL, NULL) + 2;
} else {
return push_captures(&ms, sstr, q);
}
}
} while (sstr++ < ms.src_end && !anchor);
}
setnilV(L->top-1); /* Not found. */
return 1;
}
LJLIB_CF(string_find) LJLIB_REC(.)
{
return str_find_aux(L, 1);
}
LJLIB_CF(string_match)
{
return str_find_aux(L, 0);
}
LJLIB_NOREG LJLIB_CF(string_gmatch_aux)
{
const char *p = strVdata(lj_lib_upvalue(L, 2));
GCstr *str = strV(lj_lib_upvalue(L, 1));
const char *s = strdata(str);
TValue *tvpos = lj_lib_upvalue(L, 3);
const char *src = s + tvpos->u32.lo;
MatchState ms;
ms.L = L;
ms.src_init = s;
ms.src_end = s + str->len;
for (; src <= ms.src_end; src++) {
const char *e;
ms.level = ms.depth = 0;
if ((e = match(&ms, src, p)) != NULL) {
int32_t pos = (int32_t)(e - s);
if (e == src) pos++; /* Ensure progress for empty match. */
tvpos->u32.lo = (uint32_t)pos;
return push_captures(&ms, src, e);
}
}
return 0; /* not found */
}
LJLIB_CF(string_gmatch)
{
lj_lib_checkstr(L, 1);
lj_lib_checkstr(L, 2);
L->top = L->base+3;
(L->top-1)->u64 = 0;
lj_lib_pushcc(L, lj_cf_string_gmatch_aux, FF_string_gmatch_aux, 3);
return 1;
}
static void add_s(MatchState *ms, luaL_Buffer *b, const char *s, const char *e)
{
size_t l, i;
const char *news = lua_tolstring(ms->L, 3, &l);
for (i = 0; i < l; i++) {
if (news[i] != L_ESC) {
luaL_addchar(b, news[i]);
} else {
i++; /* skip ESC */
if (!lj_char_isdigit(uchar(news[i]))) {
luaL_addchar(b, news[i]);
} else if (news[i] == '0') {
luaL_addlstring(b, s, (size_t)(e - s));
} else {
push_onecapture(ms, news[i] - '1', s, e);
luaL_addvalue(b); /* add capture to accumulated result */
}
}
}
}
static void add_value(MatchState *ms, luaL_Buffer *b,
const char *s, const char *e)
{
lua_State *L = ms->L;
switch (lua_type(L, 3)) {
case LUA_TNUMBER:
case LUA_TSTRING: {
add_s(ms, b, s, e);
return;
}
case LUA_TFUNCTION: {
int n;
lua_pushvalue(L, 3);
n = push_captures(ms, s, e);
lua_call(L, n, 1);
break;
}
case LUA_TTABLE: {
push_onecapture(ms, 0, s, e);
lua_gettable(L, 3);
break;
}
}
if (!lua_toboolean(L, -1)) { /* nil or false? */
lua_pop(L, 1);
lua_pushlstring(L, s, (size_t)(e - s)); /* keep original text */
} else if (!lua_isstring(L, -1)) {
lj_err_callerv(L, LJ_ERR_STRGSRV, luaL_typename(L, -1));
}
luaL_addvalue(b); /* add result to accumulator */
}
LJLIB_CF(string_gsub)
{
size_t srcl;
const char *src = luaL_checklstring(L, 1, &srcl);
const char *p = luaL_checkstring(L, 2);
int tr = lua_type(L, 3);
int max_s = luaL_optint(L, 4, (int)(srcl+1));
int anchor = (*p == '^') ? (p++, 1) : 0;
int n = 0;
MatchState ms;
luaL_Buffer b;
if (!(tr == LUA_TNUMBER || tr == LUA_TSTRING ||
tr == LUA_TFUNCTION || tr == LUA_TTABLE))
lj_err_arg(L, 3, LJ_ERR_NOSFT);
luaL_buffinit(L, &b);
ms.L = L;
ms.src_init = src;
ms.src_end = src+srcl;
while (n < max_s) {
const char *e;
ms.level = ms.depth = 0;
e = match(&ms, src, p);
if (e) {
n++;
add_value(&ms, &b, src, e);
}
if (e && e>src) /* non empty match? */
src = e; /* skip it */
else if (src < ms.src_end)
luaL_addchar(&b, *src++);
else
break;
if (anchor)
break;
}
luaL_addlstring(&b, src, (size_t)(ms.src_end-src));
luaL_pushresult(&b);
lua_pushinteger(L, n); /* number of substitutions */
return 2;
}
/* ------------------------------------------------------------------------ */
LJLIB_CF(string_format) LJLIB_REC(.)
{
int retry = 0;
SBuf *sb;
do {
sb = lj_buf_tmp_(L);
retry = lj_strfmt_putarg(L, sb, 1, -retry);
} while (retry > 0);
setstrV(L, L->top-1, lj_buf_str(L, sb));
lj_gc_check(L);
return 1;
}
/* ------------------------------------------------------------------------ */
#include "lj_libdef.h"
LUALIB_API int luaopen_string(lua_State *L)
{
GCtab *mt;
global_State *g;
LJ_LIB_REG(L, LUA_STRLIBNAME, string);
mt = lj_tab_new(L, 0, 1);
/* NOBARRIER: basemt is a GC root. */
g = G(L);
setgcref(basemt_it(g, LJ_TSTR), obj2gco(mt));
settabV(L, lj_tab_setstr(L, mt, mmname_str(g, MM_index)), tabV(L->top-1));
mt->nomm = (uint8_t)(~(1u<<MM_index));
#if LJ_HASBUFFER
lj_lib_prereg(L, LUA_STRLIBNAME ".buffer", luaopen_string_buffer, tabV(L->top-1));
#endif
return 1;
}
