src/lj_strfmt.c

   1 /*
   2 ** String formatting.
   3 ** Copyright (C) 2005-2025 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #include <stdio.h>
   7
   8 #define lj_strfmt_c
   9 #define LUA_CORE
  10
  11 #include "lj_obj.h"
  12 #include "lj_err.h"
  13 #include "lj_buf.h"
  14 #include "lj_str.h"
  15 #include "lj_meta.h"
  16 #include "lj_state.h"
  17 #include "lj_char.h"
  18 #include "lj_strfmt.h"
  19 #if LJ_HASFFI
  20 #include "lj_ctype.h"
  21 #endif
  22 #include "lj_lib.h"
  23
  24 /* -- Format parser ------------------------------------------------------- */
  25
  26 static const uint8_t strfmt_map[('x'-'A')+1] = {
  27   STRFMT_A,0,0,0,STRFMT_E,STRFMT_F,STRFMT_G,0,0,0,0,0,0,
  28   0,0,0,0,0,0,0,0,0,0,STRFMT_X,0,0,
  29   0,0,0,0,0,0,
  30   STRFMT_A,0,STRFMT_C,STRFMT_D,STRFMT_E,STRFMT_F,STRFMT_G,0,STRFMT_I,0,0,0,0,
  31   0,STRFMT_O,STRFMT_P,STRFMT_Q,0,STRFMT_S,0,STRFMT_U,0,0,STRFMT_X
  32 };
  33
  34 SFormat LJ_FASTCALL lj_strfmt_parse(FormatState *fs)
  35 {
  36   const uint8_t *p = fs->p, *e = fs->e;
  37   fs->str = (const char *)p;
  38   for (; p < e; p++) {
  39     if (*p == '%') {  /* Escape char? */
  40       if (p[1] == '%') {  /* '%%'? */
  41         fs->p = ++p+1;
  42         goto retlit;
  43       } else {
  44         SFormat sf = 0;
  45         uint32_t c;
  46         if (p != (const uint8_t *)fs->str)
  47           break;
  48         for (p++; (uint32_t)*p - ' ' <= (uint32_t)('0' - ' '); p++) {
  49           /* Parse flags. */
  50           if (*p == '-') sf |= STRFMT_F_LEFT;
  51           else if (*p == '+') sf |= STRFMT_F_PLUS;
  52           else if (*p == '0') sf |= STRFMT_F_ZERO;
  53           else if (*p == ' ') sf |= STRFMT_F_SPACE;
  54           else if (*p == '#') sf |= STRFMT_F_ALT;
  55           else break;
  56         }
  57         if ((uint32_t)*p - '0' < 10) {  /* Parse width. */
  58           uint32_t width = (uint32_t)*p++ - '0';
  59           if ((uint32_t)*p - '0' < 10)
  60             width = (uint32_t)*p++ - '0' + width*10;
  61           sf |= (width << STRFMT_SH_WIDTH);
  62         }
  63         if (*p == '.') {  /* Parse precision. */
  64           uint32_t prec = 0;
  65           p++;
  66           if ((uint32_t)*p - '0' < 10) {
  67             prec = (uint32_t)*p++ - '0';
  68             if ((uint32_t)*p - '0' < 10)
  69               prec = (uint32_t)*p++ - '0' + prec*10;
  70           }
  71           sf |= ((prec+1) << STRFMT_SH_PREC);
  72         }
  73         /* Parse conversion. */
  74         c = (uint32_t)*p - 'A';
  75         if (LJ_LIKELY(c <= (uint32_t)('x' - 'A'))) {
  76           uint32_t sx = strfmt_map[c];
  77           if (sx) {
  78             fs->p = p+1;
  79             return (sf | sx | ((c & 0x20) ? 0 : STRFMT_F_UPPER));
  80           }
  81         }
  82         /* Return error location. */
  83         if (*p >= 32) p++;
  84         fs->len = (MSize)(p - (const uint8_t *)fs->str);
  85         fs->p = fs->e;
  86         return STRFMT_ERR;
  87       }
  88     }
  89   }
  90   fs->p = p;
  91 retlit:
  92   fs->len = (MSize)(p - (const uint8_t *)fs->str);
  93   return fs->len ? STRFMT_LIT : STRFMT_EOF;
  94 }
  95
  96 /* -- Raw conversions ----------------------------------------------------- */
  97
  98 #define WINT_R(x, sh, sc) \
  99   { uint32_t d = (x*(((1<<sh)+sc-1)/sc))>>sh; x -= d*sc; *p++ = (char)('0'+d); }
 100
 101 /* Write integer to buffer. */
 102 char * LJ_FASTCALL lj_strfmt_wint(char *p, int32_t k)
 103 {
 104   uint32_t u = (uint32_t)k;
 105   if (k < 0) { u = ~u+1u; *p++ = '-'; }
 106   if (u < 10000) {
 107     if (u < 10) goto dig1;
 108     if (u < 100) goto dig2;
 109     if (u < 1000) goto dig3;
 110   } else {
 111     uint32_t v = u / 10000; u -= v * 10000;
 112     if (v < 10000) {
 113       if (v < 10) goto dig5;
 114       if (v < 100) goto dig6;
 115       if (v < 1000) goto dig7;
 116     } else {
 117       uint32_t w = v / 10000; v -= w * 10000;
 118       if (w >= 10) WINT_R(w, 10, 10)
 119       *p++ = (char)('0'+w);
 120     }
 121     WINT_R(v, 23, 1000)
 122     dig7: WINT_R(v, 12, 100)
 123     dig6: WINT_R(v, 10, 10)
 124     dig5: *p++ = (char)('0'+v);
 125   }
 126   WINT_R(u, 23, 1000)
 127   dig3: WINT_R(u, 12, 100)
 128   dig2: WINT_R(u, 10, 10)
 129   dig1: *p++ = (char)('0'+u);
 130   return p;
 131 }
 132 #undef WINT_R
 133
 134 /* Write pointer to buffer. */
 135 char * LJ_FASTCALL lj_strfmt_wptr(char *p, const void *v)
 136 {
 137   ptrdiff_t x = (ptrdiff_t)v;
 138   MSize i, n = STRFMT_MAXBUF_PTR;
 139   if (x == 0) {
 140     *p++ = 'N'; *p++ = 'U'; *p++ = 'L'; *p++ = 'L';
 141     return p;
 142   }
 143 #if LJ_64
 144   /* Shorten output for 64 bit pointers. */
 145   n = 2+2*4+((x >> 32) ? 2+2*(lj_fls((uint32_t)(x >> 32))>>3) : 0);
 146 #endif
 147   p[0] = '0';
 148   p[1] = 'x';
 149   for (i = n-1; i >= 2; i--, x >>= 4)
 150     p[i] = "0123456789abcdef"[(x & 15)];
 151   return p+n;
 152 }
 153
 154 /* Write ULEB128 to buffer. */
 155 char * LJ_FASTCALL lj_strfmt_wuleb128(char *p, uint32_t v)
 156 {
 157   for (; v >= 0x80; v >>= 7)
 158     *p++ = (char)((v & 0x7f) | 0x80);
 159   *p++ = (char)v;
 160   return p;
 161 }
 162
 163 /* Return string or write number to tmp buffer and return pointer to start. */
 164 const char *lj_strfmt_wstrnum(lua_State *L, cTValue *o, MSize *lenp)
 165 {
 166   SBuf *sb;
 167   if (tvisstr(o)) {
 168     *lenp = strV(o)->len;
 169     return strVdata(o);
 170   } else if (tvisbuf(o)) {
 171     SBufExt *sbx = bufV(o);
 172     *lenp = sbufxlen(sbx);
 173     return sbx->r;
 174   } else if (tvisint(o)) {
 175     sb = lj_strfmt_putint(lj_buf_tmp_(L), intV(o));
 176   } else if (tvisnum(o)) {
 177     sb = lj_strfmt_putfnum(lj_buf_tmp_(L), STRFMT_G14, o->n);
 178   } else {
 179     return NULL;
 180   }
 181   *lenp = sbuflen(sb);
 182   return sb->b;
 183 }
 184
 185 /* -- Unformatted conversions to buffer ----------------------------------- */
 186
 187 /* Add integer to buffer. */
 188 SBuf * LJ_FASTCALL lj_strfmt_putint(SBuf *sb, int32_t k)
 189 {
 190   sb->w = lj_strfmt_wint(lj_buf_more(sb, STRFMT_MAXBUF_INT), k);
 191   return sb;
 192 }
 193
 194 #if LJ_HASJIT
 195 /* Add number to buffer. */
 196 SBuf * LJ_FASTCALL lj_strfmt_putnum(SBuf *sb, cTValue *o)
 197 {
 198   return lj_strfmt_putfnum(sb, STRFMT_G14, o->n);
 199 }
 200 #endif
 201
 202 SBuf * LJ_FASTCALL lj_strfmt_putptr(SBuf *sb, const void *v)
 203 {
 204   sb->w = lj_strfmt_wptr(lj_buf_more(sb, STRFMT_MAXBUF_PTR), v);
 205   return sb;
 206 }
 207
 208 /* Add quoted string to buffer. */
 209 static SBuf *strfmt_putquotedlen(SBuf *sb, const char *s, MSize len)
 210 {
 211   lj_buf_putb(sb, '"');
 212   while (len--) {
 213     uint32_t c = (uint32_t)(uint8_t)*s++;
 214     char *w = lj_buf_more(sb, 4);
 215     if (c == '"' || c == '\\' || c == '\n') {
 216       *w++ = '\\';
 217     } else if (lj_char_iscntrl(c)) {  /* This can only be 0-31 or 127. */
 218       uint32_t d;
 219       *w++ = '\\';
 220       if (c >= 100 || lj_char_isdigit((uint8_t)*s)) {
 221         *w++ = (char)('0'+(c >= 100)); if (c >= 100) c -= 100;
 222         goto tens;
 223       } else if (c >= 10) {
 224       tens:
 225         d = (c * 205) >> 11; c -= d * 10; *w++ = (char)('0'+d);
 226       }
 227       c += '0';
 228     }
 229     *w++ = (char)c;
 230     sb->w = w;
 231   }
 232   lj_buf_putb(sb, '"');
 233   return sb;
 234 }
 235
 236 #if LJ_HASJIT
 237 SBuf * LJ_FASTCALL lj_strfmt_putquoted(SBuf *sb, GCstr *str)
 238 {
 239   return strfmt_putquotedlen(sb, strdata(str), str->len);
 240 }
 241 #endif
 242
 243 /* -- Formatted conversions to buffer ------------------------------------- */
 244
 245 /* Add formatted char to buffer. */
 246 SBuf *lj_strfmt_putfchar(SBuf *sb, SFormat sf, int32_t c)
 247 {
 248   MSize width = STRFMT_WIDTH(sf);
 249   char *w = lj_buf_more(sb, width > 1 ? width : 1);
 250   if ((sf & STRFMT_F_LEFT)) *w++ = (char)c;
 251   while (width-- > 1) *w++ = ' ';
 252   if (!(sf & STRFMT_F_LEFT)) *w++ = (char)c;
 253   sb->w = w;
 254   return sb;
 255 }
 256
 257 /* Add formatted string to buffer. */
 258 static SBuf *strfmt_putfstrlen(SBuf *sb, SFormat sf, const char *s, MSize len)
 259 {
 260   MSize width = STRFMT_WIDTH(sf);
 261   char *w;
 262   if (len > STRFMT_PREC(sf)) len = STRFMT_PREC(sf);
 263   w = lj_buf_more(sb, width > len ? width : len);
 264   if ((sf & STRFMT_F_LEFT)) w = lj_buf_wmem(w, s, len);
 265   while (width-- > len) *w++ = ' ';
 266   if (!(sf & STRFMT_F_LEFT)) w = lj_buf_wmem(w, s, len);
 267   sb->w = w;
 268   return sb;
 269 }
 270
 271 #if LJ_HASJIT
 272 SBuf *lj_strfmt_putfstr(SBuf *sb, SFormat sf, GCstr *str)
 273 {
 274   return strfmt_putfstrlen(sb, sf, strdata(str), str->len);
 275 }
 276 #endif
 277
 278 /* Add formatted signed/unsigned integer to buffer. */
 279 SBuf *lj_strfmt_putfxint(SBuf *sb, SFormat sf, uint64_t k)
 280 {
 281   char buf[STRFMT_MAXBUF_XINT], *q = buf + sizeof(buf), *w;
 282 #ifdef LUA_USE_ASSERT
 283   char *ws;
 284 #endif
 285   MSize prefix = 0, len, prec, pprec, width, need;
 286
 287   /* Figure out signed prefixes. */
 288   if (STRFMT_TYPE(sf) == STRFMT_INT) {
 289     if ((int64_t)k < 0) {
 290       k = ~k+1u;
 291       prefix = 256 + '-';
 292     } else if ((sf & STRFMT_F_PLUS)) {
 293       prefix = 256 + '+';
 294     } else if ((sf & STRFMT_F_SPACE)) {
 295       prefix = 256 + ' ';
 296     }
 297   }
 298
 299   /* Convert number and store to fixed-size buffer in reverse order. */
 300   prec = STRFMT_PREC(sf);
 301   if ((int32_t)prec >= 0) sf &= ~STRFMT_F_ZERO;
 302   if (k == 0) {  /* Special-case zero argument. */
 303     if (prec != 0 ||
 304         (sf & (STRFMT_T_OCT|STRFMT_F_ALT)) == (STRFMT_T_OCT|STRFMT_F_ALT))
 305       *--q = '0';
 306   } else if (!(sf & (STRFMT_T_HEX|STRFMT_T_OCT))) {  /* Decimal. */
 307     uint32_t k2;
 308     while ((k >> 32)) { *--q = (char)('0' + k % 10); k /= 10; }
 309     k2 = (uint32_t)k;
 310     do { *--q = (char)('0' + k2 % 10); k2 /= 10; } while (k2);
 311   } else if ((sf & STRFMT_T_HEX)) {  /* Hex. */
 312     const char *hexdig = (sf & STRFMT_F_UPPER) ? "0123456789ABCDEF" :
 313                                                  "0123456789abcdef";
 314     do { *--q = hexdig[(k & 15)]; k >>= 4; } while (k);
 315     if ((sf & STRFMT_F_ALT)) prefix = 512 + ((sf & STRFMT_F_UPPER) ? 'X' : 'x');
 316   } else {  /* Octal. */
 317     do { *--q = (char)('0' + (uint32_t)(k & 7)); k >>= 3; } while (k);
 318     if ((sf & STRFMT_F_ALT)) *--q = '0';
 319   }
 320
 321   /* Calculate sizes. */
 322   len = (MSize)(buf + sizeof(buf) - q);
 323   if ((int32_t)len >= (int32_t)prec) prec = len;
 324   width = STRFMT_WIDTH(sf);
 325   pprec = prec + (prefix >> 8);
 326   need = width > pprec ? width : pprec;
 327   w = lj_buf_more(sb, need);
 328 #ifdef LUA_USE_ASSERT
 329   ws = w;
 330 #endif
 331
 332   /* Format number with leading/trailing whitespace and zeros. */
 333   if ((sf & (STRFMT_F_LEFT|STRFMT_F_ZERO)) == 0)
 334     while (width-- > pprec) *w++ = ' ';
 335   if (prefix) {
 336     if ((char)prefix >= 'X') *w++ = '0';
 337     *w++ = (char)prefix;
 338   }
 339   if ((sf & (STRFMT_F_LEFT|STRFMT_F_ZERO)) == STRFMT_F_ZERO)
 340     while (width-- > pprec) *w++ = '0';
 341   while (prec-- > len) *w++ = '0';
 342   while (q < buf + sizeof(buf)) *w++ = *q++;  /* Add number itself. */
 343   if ((sf & STRFMT_F_LEFT))
 344     while (width-- > pprec) *w++ = ' ';
 345
 346   lj_assertX(need == (MSize)(w - ws), "miscalculated format size");
 347   sb->w = w;
 348   return sb;
 349 }
 350
 351 /* Add number formatted as signed integer to buffer. */
 352 SBuf *lj_strfmt_putfnum_int(SBuf *sb, SFormat sf, lua_Number n)
 353 {
 354   int64_t k = (int64_t)n;
 355   if (checki32(k) && sf == STRFMT_INT)
 356     return lj_strfmt_putint(sb, (int32_t)k);  /* Shortcut for plain %d. */
 357   else
 358     return lj_strfmt_putfxint(sb, sf, (uint64_t)k);
 359 }
 360
 361 /* Add number formatted as unsigned integer to buffer. */
 362 SBuf *lj_strfmt_putfnum_uint(SBuf *sb, SFormat sf, lua_Number n)
 363 {
 364   int64_t k;
 365   if (n >= 9223372036854775808.0)
 366     k = (int64_t)(n - 18446744073709551616.0);
 367   else
 368     k = (int64_t)n;
 369   return lj_strfmt_putfxint(sb, sf, (uint64_t)k);
 370 }
 371
 372 /* Format stack arguments to buffer. */
 373 int lj_strfmt_putarg(lua_State *L, SBuf *sb, int arg, int retry)
 374 {
 375   int narg = (int)(L->top - L->base);
 376   GCstr *fmt = lj_lib_checkstr(L, arg);
 377   FormatState fs;
 378   SFormat sf;
 379   lj_strfmt_init(&fs, strdata(fmt), fmt->len);
 380   while ((sf = lj_strfmt_parse(&fs)) != STRFMT_EOF) {
 381     if (sf == STRFMT_LIT) {
 382       lj_buf_putmem(sb, fs.str, fs.len);
 383     } else if (sf == STRFMT_ERR) {
 384       lj_err_callerv(L, LJ_ERR_STRFMT,
 385                      strdata(lj_str_new(L, fs.str, fs.len)));
 386     } else {
 387       TValue *o = &L->base[arg++];
 388       if (arg > narg)
 389         lj_err_arg(L, arg, LJ_ERR_NOVAL);
 390       switch (STRFMT_TYPE(sf)) {
 391       case STRFMT_INT:
 392         if (tvisint(o)) {
 393           int32_t k = intV(o);
 394           if (sf == STRFMT_INT)
 395             lj_strfmt_putint(sb, k);  /* Shortcut for plain %d. */
 396           else
 397             lj_strfmt_putfxint(sb, sf, k);
 398           break;
 399         }
 400 #if LJ_HASFFI
 401         if (tviscdata(o)) {
 402           GCcdata *cd = cdataV(o);
 403           if (cd->ctypeid == CTID_INT64 || cd->ctypeid == CTID_UINT64) {
 404             lj_strfmt_putfxint(sb, sf, *(uint64_t *)cdataptr(cd));
 405             break;
 406           }
 407         }
 408 #endif
 409         lj_strfmt_putfnum_int(sb, sf, lj_lib_checknum(L, arg));
 410         break;
 411       case STRFMT_UINT:
 412         if (tvisint(o)) {
 413           lj_strfmt_putfxint(sb, sf, intV(o));
 414           break;
 415         }
 416 #if LJ_HASFFI
 417         if (tviscdata(o)) {
 418           GCcdata *cd = cdataV(o);
 419           if (cd->ctypeid == CTID_INT64 || cd->ctypeid == CTID_UINT64) {
 420             lj_strfmt_putfxint(sb, sf, *(uint64_t *)cdataptr(cd));
 421             break;
 422           }
 423         }
 424 #endif
 425         lj_strfmt_putfnum_uint(sb, sf, lj_lib_checknum(L, arg));
 426         break;
 427       case STRFMT_NUM:
 428         lj_strfmt_putfnum(sb, sf, lj_lib_checknum(L, arg));
 429         break;
 430       case STRFMT_STR: {
 431         MSize len;
 432         const char *s;
 433         cTValue *mo;
 434         if (LJ_UNLIKELY(!tvisstr(o) && !tvisbuf(o)) && retry >= 0 &&
 435             !tvisnil(mo = lj_meta_lookup(L, o, MM_tostring))) {
 436           /* Call __tostring metamethod once. */
 437           copyTV(L, L->top++, mo);
 438           copyTV(L, L->top++, o);
 439           lua_call(L, 1, 1);
 440           o = &L->base[arg-1];  /* Stack may have been reallocated. */
 441           copyTV(L, o, --L->top);  /* Replace inline for retry. */
 442           if (retry < 2) {  /* Global buffer may have been overwritten. */
 443             retry = 1;
 444             break;
 445           }
 446         }
 447         if (LJ_LIKELY(tvisstr(o))) {
 448           len = strV(o)->len;
 449           s = strVdata(o);
 450 #if LJ_HASBUFFER
 451         } else if (tvisbuf(o)) {
 452           SBufExt *sbx = bufV(o);
 453           if (sbx == (SBufExt *)sb) lj_err_arg(L, arg+1, LJ_ERR_BUFFER_SELF);
 454           len = sbufxlen(sbx);
 455           s = sbx->r;
 456 #endif
 457         } else {
 458           GCstr *str = lj_strfmt_obj(L, o);
 459           len = str->len;
 460           s = strdata(str);
 461         }
 462         if ((sf & STRFMT_T_QUOTED))
 463           strfmt_putquotedlen(sb, s, len);  /* No formatting. */
 464         else
 465           strfmt_putfstrlen(sb, sf, s, len);
 466         break;
 467         }
 468       case STRFMT_CHAR:
 469         lj_strfmt_putfchar(sb, sf, lj_lib_checkint(L, arg));
 470         break;
 471       case STRFMT_PTR:  /* No formatting. */
 472         lj_strfmt_putptr(sb, lj_obj_ptr(G(L), o));
 473         break;
 474       default:
 475         lj_assertL(0, "bad string format type");
 476         break;
 477       }
 478     }
 479   }
 480   return retry;
 481 }
 482
 483 /* -- Conversions to strings ---------------------------------------------- */
 484
 485 /* Convert integer to string. */
 486 GCstr * LJ_FASTCALL lj_strfmt_int(lua_State *L, int32_t k)
 487 {
 488   char buf[STRFMT_MAXBUF_INT];
 489   MSize len = (MSize)(lj_strfmt_wint(buf, k) - buf);
 490   return lj_str_new(L, buf, len);
 491 }
 492
 493 /* Convert integer or number to string. */
 494 GCstr * LJ_FASTCALL lj_strfmt_number(lua_State *L, cTValue *o)
 495 {
 496   return tvisint(o) ? lj_strfmt_int(L, intV(o)) : lj_strfmt_num(L, o);
 497 }
 498
 499 #if LJ_HASJIT
 500 /* Convert char value to string. */
 501 GCstr * LJ_FASTCALL lj_strfmt_char(lua_State *L, int c)
 502 {
 503   char buf[1];
 504   buf[0] = c;
 505   return lj_str_new(L, buf, 1);
 506 }
 507 #endif
 508
 509 /* Raw conversion of object to string. */
 510 GCstr * LJ_FASTCALL lj_strfmt_obj(lua_State *L, cTValue *o)
 511 {
 512   if (tvisstr(o)) {
 513     return strV(o);
 514   } else if (tvisnumber(o)) {
 515     return lj_strfmt_number(L, o);
 516   } else if (tvisnil(o)) {
 517     return lj_str_newlit(L, "nil");
 518   } else if (tvisfalse(o)) {
 519     return lj_str_newlit(L, "false");
 520   } else if (tvistrue(o)) {
 521     return lj_str_newlit(L, "true");
 522   } else {
 523     char buf[8+2+2+16], *p = buf;
 524     p = lj_buf_wmem(p, lj_typename(o), (MSize)strlen(lj_typename(o)));
 525     *p++ = ':'; *p++ = ' ';
 526     if (tvisfunc(o) && isffunc(funcV(o))) {
 527       p = lj_buf_wmem(p, "builtin#", 8);
 528       p = lj_strfmt_wint(p, funcV(o)->c.ffid);
 529     } else {
 530       p = lj_strfmt_wptr(p, lj_obj_ptr(G(L), o));
 531     }
 532     return lj_str_new(L, buf, (size_t)(p - buf));
 533   }
 534 }
 535
 536 /* -- Internal string formatting ------------------------------------------ */
 537
 538 /*
 539 ** These functions are only used for lua_pushfstring(), lua_pushvfstring()
 540 ** and for internal string formatting (e.g. error messages). Caveat: unlike
 541 ** string.format(), only a limited subset of formats and flags are supported!
 542 **
 543 ** LuaJIT has support for a couple more formats than Lua 5.1/5.2:
 544 ** - %d %u %o %x with full formatting, 32 bit integers only.
 545 ** - %f and other FP formats are really %.14g.
 546 ** - %s %c %p without formatting.
 547 */
 548
 549 /* Push formatted message as a string object to Lua stack. va_list variant. */
 550 const char *lj_strfmt_pushvf(lua_State *L, const char *fmt, va_list argp)
 551 {
 552   SBuf *sb = lj_buf_tmp_(L);
 553   FormatState fs;
 554   SFormat sf;
 555   GCstr *str;
 556   lj_strfmt_init(&fs, fmt, (MSize)strlen(fmt));
 557   while ((sf = lj_strfmt_parse(&fs)) != STRFMT_EOF) {
 558     switch (STRFMT_TYPE(sf)) {
 559     case STRFMT_LIT:
 560       lj_buf_putmem(sb, fs.str, fs.len);
 561       break;
 562     case STRFMT_INT:
 563       lj_strfmt_putfxint(sb, sf, va_arg(argp, int32_t));
 564       break;
 565     case STRFMT_UINT:
 566       lj_strfmt_putfxint(sb, sf, va_arg(argp, uint32_t));
 567       break;
 568     case STRFMT_NUM:
 569       lj_strfmt_putfnum(sb, STRFMT_G14, va_arg(argp, lua_Number));
 570       break;
 571     case STRFMT_STR: {
 572       const char *s = va_arg(argp, char *);
 573       if (s == NULL) s = "(null)";
 574       lj_buf_putmem(sb, s, (MSize)strlen(s));
 575       break;
 576       }
 577     case STRFMT_CHAR:
 578       lj_buf_putb(sb, va_arg(argp, int));
 579       break;
 580     case STRFMT_PTR:
 581       lj_strfmt_putptr(sb, va_arg(argp, void *));
 582       break;
 583     case STRFMT_ERR:
 584     default:
 585       lj_buf_putb(sb, '?');
 586       lj_assertL(0, "bad string format near offset %d", fs.len);
 587       break;
 588     }
 589   }
 590   str = lj_buf_str(L, sb);
 591   setstrV(L, L->top, str);
 592   incr_top(L);
 593   return strdata(str);
 594 }
 595
 596 /* Push formatted message as a string object to Lua stack. Vararg variant. */
 597 const char *lj_strfmt_pushf(lua_State *L, const char *fmt, ...)
 598 {
 599   const char *msg;
 600   va_list argp;
 601   va_start(argp, fmt);
 602   msg = lj_strfmt_pushvf(L, fmt, argp);
 603   va_end(argp);
 604   return msg;
 605 }
 606