src/printf.c

   1 /*
   2 ** The "printf" code that follows dates from the 1980's.  It is in
   3 ** the public domain.
   4 **
   5 **************************************************************************
   6 **
   7 ** This file contains code for a set of "printf"-like routines.  These
   8 ** routines format strings much like the printf() from the standard C
   9 ** library, though the implementation here has enhancements to support
  10 ** SQLite.
  11 */
  12 #include "sqliteInt.h"
  13
  14 /*
  15 ** Conversion types fall into various categories as defined by the
  16 ** following enumeration.
  17 */
  18 #define etRADIX       0 /* non-decimal integer types.  %x %o */
  19 #define etFLOAT       1 /* Floating point.  %f */
  20 #define etEXP         2 /* Exponentional notation. %e and %E */
  21 #define etGENERIC     3 /* Floating or exponential, depending on exponent. %g */
  22 #define etSIZE        4 /* Return number of characters processed so far. %n */
  23 #define etSTRING      5 /* Strings. %s */
  24 #define etDYNSTRING   6 /* Dynamically allocated strings. %z */
  25 #define etPERCENT     7 /* Percent symbol. %% */
  26 #define etCHARX       8 /* Characters. %c */
  27 /* The rest are extensions, not normally found in printf() */
  28 #define etSQLESCAPE   9 /* Strings with '\'' doubled.  %q */
  29 #define etSQLESCAPE2 10 /* Strings with '\'' doubled and enclosed in '',
  30                           NULL pointers replaced by SQL NULL.  %Q */
  31 #define etTOKEN      11 /* a pointer to a Token structure */
  32 #define etSRCITEM    12 /* a pointer to a SrcItem */
  33 #define etPOINTER    13 /* The %p conversion */
  34 #define etSQLESCAPE3 14 /* %w -> Strings with '\"' doubled */
  35 #define etORDINAL    15 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
  36 #define etDECIMAL    16 /* %d or %u, but not %x, %o */
  37
  38 #define etINVALID    17 /* Any unrecognized conversion type */
  39
  40
  41 /*
  42 ** An "etByte" is an 8-bit unsigned value.
  43 */
  44 typedef unsigned char etByte;
  45
  46 /*
  47 ** Each builtin conversion character (ex: the 'd' in "%d") is described
  48 ** by an instance of the following structure
  49 */
  50 typedef struct et_info {   /* Information about each format field */
  51   char fmttype;            /* The format field code letter */
  52   etByte base;             /* The base for radix conversion */
  53   etByte flags;            /* One or more of FLAG_ constants below */
  54   etByte type;             /* Conversion paradigm */
  55   etByte charset;          /* Offset into aDigits[] of the digits string */
  56   etByte prefix;           /* Offset into aPrefix[] of the prefix string */
  57 } et_info;
  58
  59 /*
  60 ** Allowed values for et_info.flags
  61 */
  62 #define FLAG_SIGNED    1     /* True if the value to convert is signed */
  63 #define FLAG_STRING    4     /* Allow infinite precision */
  64
  65
  66 /*
  67 ** The following table is searched linearly, so it is good to put the
  68 ** most frequently used conversion types first.
  69 */
  70 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
  71 static const char aPrefix[] = "-x0\000X0";
  72 static const et_info fmtinfo[] = {
  73   {  'd', 10, 1, etDECIMAL,    0,  0 },
  74   {  's',  0, 4, etSTRING,     0,  0 },
  75   {  'g',  0, 1, etGENERIC,    30, 0 },
  76   {  'z',  0, 4, etDYNSTRING,  0,  0 },
  77   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
  78   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
  79   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
  80   {  'c',  0, 0, etCHARX,      0,  0 },
  81   {  'o',  8, 0, etRADIX,      0,  2 },
  82   {  'u', 10, 0, etDECIMAL,    0,  0 },
  83   {  'x', 16, 0, etRADIX,      16, 1 },
  84   {  'X', 16, 0, etRADIX,      0,  4 },
  85 #ifndef SQLITE_OMIT_FLOATING_POINT
  86   {  'f',  0, 1, etFLOAT,      0,  0 },
  87   {  'e',  0, 1, etEXP,        30, 0 },
  88   {  'E',  0, 1, etEXP,        14, 0 },
  89   {  'G',  0, 1, etGENERIC,    14, 0 },
  90 #endif
  91   {  'i', 10, 1, etDECIMAL,    0,  0 },
  92   {  'n',  0, 0, etSIZE,       0,  0 },
  93   {  '%',  0, 0, etPERCENT,    0,  0 },
  94   {  'p', 16, 0, etPOINTER,    0,  1 },
  95
  96   /* All the rest are undocumented and are for internal use only */
  97   {  'T',  0, 0, etTOKEN,      0,  0 },
  98   {  'S',  0, 0, etSRCITEM,    0,  0 },
  99   {  'r', 10, 1, etORDINAL,    0,  0 },
 100 };
 101
 102 /* Notes:
 103 **
 104 **    %S    Takes a pointer to SrcItem.  Shows name or database.name
 105 **    %!S   Like %S but prefer the zName over the zAlias
 106 */
 107
 108 /*
 109 ** Set the StrAccum object to an error mode.
 110 */
 111 void sqlite3StrAccumSetError(StrAccum *p, u8 eError){
 112   assert( eError==SQLITE_NOMEM || eError==SQLITE_TOOBIG );
 113   p->accError = eError;
 114   if( p->mxAlloc ) sqlite3_str_reset(p);
 115   if( eError==SQLITE_TOOBIG ) sqlite3ErrorToParser(p->db, eError);
 116 }
 117
 118 /*
 119 ** Extra argument values from a PrintfArguments object
 120 */
 121 static sqlite3_int64 getIntArg(PrintfArguments *p){
 122   if( p->nArg<=p->nUsed ) return 0;
 123   return sqlite3_value_int64(p->apArg[p->nUsed++]);
 124 }
 125 static double getDoubleArg(PrintfArguments *p){
 126   if( p->nArg<=p->nUsed ) return 0.0;
 127   return sqlite3_value_double(p->apArg[p->nUsed++]);
 128 }
 129 static char *getTextArg(PrintfArguments *p){
 130   if( p->nArg<=p->nUsed ) return 0;
 131   return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
 132 }
 133
 134 /*
 135 ** Allocate memory for a temporary buffer needed for printf rendering.
 136 **
 137 ** If the requested size of the temp buffer is larger than the size
 138 ** of the output buffer in pAccum, then cause an SQLITE_TOOBIG error.
 139 ** Do the size check before the memory allocation to prevent rogue
 140 ** SQL from requesting large allocations using the precision or width
 141 ** field of the printf() function.
 142 */
 143 static char *printfTempBuf(sqlite3_str *pAccum, sqlite3_int64 n){
 144   char *z;
 145   if( pAccum->accError ) return 0;
 146   if( n>pAccum->nAlloc && n>pAccum->mxAlloc ){
 147     sqlite3StrAccumSetError(pAccum, SQLITE_TOOBIG);
 148     return 0;
 149   }
 150   z = sqlite3DbMallocRaw(pAccum->db, n);
 151   if( z==0 ){
 152     sqlite3StrAccumSetError(pAccum, SQLITE_NOMEM);
 153   }
 154   return z;
 155 }
 156
 157 /*
 158 ** On machines with a small stack size, you can redefine the
 159 ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
 160 */
 161 #ifndef SQLITE_PRINT_BUF_SIZE
 162 # define SQLITE_PRINT_BUF_SIZE 70
 163 #endif
 164 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
 165
 166 /*
 167 ** Hard limit on the precision of floating-point conversions.
 168 */
 169 #ifndef SQLITE_PRINTF_PRECISION_LIMIT
 170 # define SQLITE_FP_PRECISION_LIMIT 100000000
 171 #endif
 172
 173 /*
 174 ** Render a string given by "fmt" into the StrAccum object.
 175 */
 176 void sqlite3_str_vappendf(
 177   sqlite3_str *pAccum,       /* Accumulate results here */
 178   const char *fmt,           /* Format string */
 179   va_list ap                 /* arguments */
 180 ){
 181   int c;                     /* Next character in the format string */
 182   char *bufpt;               /* Pointer to the conversion buffer */
 183   int precision;             /* Precision of the current field */
 184   int length;                /* Length of the field */
 185   int idx;                   /* A general purpose loop counter */
 186   int width;                 /* Width of the current field */
 187   etByte flag_leftjustify;   /* True if "-" flag is present */
 188   etByte flag_prefix;        /* '+' or ' ' or 0 for prefix */
 189   etByte flag_alternateform; /* True if "#" flag is present */
 190   etByte flag_altform2;      /* True if "!" flag is present */
 191   etByte flag_zeropad;       /* True if field width constant starts with zero */
 192   etByte flag_long;          /* 1 for the "l" flag, 2 for "ll", 0 by default */
 193   etByte done;               /* Loop termination flag */
 194   etByte cThousand;          /* Thousands separator for %d and %u */
 195   etByte xtype = etINVALID;  /* Conversion paradigm */
 196   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
 197   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
 198   sqlite_uint64 longvalue;   /* Value for integer types */
 199   double realvalue;          /* Value for real types */
 200   const et_info *infop;      /* Pointer to the appropriate info structure */
 201   char *zOut;                /* Rendering buffer */
 202   int nOut;                  /* Size of the rendering buffer */
 203   char *zExtra = 0;          /* Malloced memory used by some conversion */
 204   int exp, e2;               /* exponent of real numbers */
 205   etByte flag_dp;            /* True if decimal point should be shown */
 206   etByte flag_rtz;           /* True if trailing zeros should be removed */
 207
 208   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
 209   char buf[etBUFSIZE];       /* Conversion buffer */
 210
 211   /* pAccum never starts out with an empty buffer that was obtained from
 212   ** malloc().  This precondition is required by the mprintf("%z...")
 213   ** optimization. */
 214   assert( pAccum->nChar>0 || (pAccum->printfFlags&SQLITE_PRINTF_MALLOCED)==0 );
 215
 216   bufpt = 0;
 217   if( (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC)!=0 ){
 218     pArgList = va_arg(ap, PrintfArguments*);
 219     bArgList = 1;
 220   }else{
 221     bArgList = 0;
 222   }
 223   for(; (c=(*fmt))!=0; ++fmt){
 224     if( c!='%' ){
 225       bufpt = (char *)fmt;
 226 #if HAVE_STRCHRNUL
 227       fmt = strchrnul(fmt, '%');
 228 #else
 229       do{ fmt++; }while( *fmt && *fmt != '%' );
 230 #endif
 231       sqlite3_str_append(pAccum, bufpt, (int)(fmt - bufpt));
 232       if( *fmt==0 ) break;
 233     }
 234     if( (c=(*++fmt))==0 ){
 235       sqlite3_str_append(pAccum, "%", 1);
 236       break;
 237     }
 238     /* Find out what flags are present */
 239     flag_leftjustify = flag_prefix = cThousand =
 240      flag_alternateform = flag_altform2 = flag_zeropad = 0;
 241     done = 0;
 242     width = 0;
 243     flag_long = 0;
 244     precision = -1;
 245     do{
 246       switch( c ){
 247         case '-':   flag_leftjustify = 1;     break;
 248         case '+':   flag_prefix = '+';        break;
 249         case ' ':   flag_prefix = ' ';        break;
 250         case '#':   flag_alternateform = 1;   break;
 251         case '!':   flag_altform2 = 1;        break;
 252         case '0':   flag_zeropad = 1;         break;
 253         case ',':   cThousand = ',';          break;
 254         default:    done = 1;                 break;
 255         case 'l': {
 256           flag_long = 1;
 257           c = *++fmt;
 258           if( c=='l' ){
 259             c = *++fmt;
 260             flag_long = 2;
 261           }
 262           done = 1;
 263           break;
 264         }
 265         case '1': case '2': case '3': case '4': case '5':
 266         case '6': case '7': case '8': case '9': {
 267           unsigned wx = c - '0';
 268           while( (c = *++fmt)>='0' && c<='9' ){
 269             wx = wx*10 + c - '0';
 270           }
 271           testcase( wx>0x7fffffff );
 272           width = wx & 0x7fffffff;
 273 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
 274           if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
 275             width = SQLITE_PRINTF_PRECISION_LIMIT;
 276           }
 277 #endif
 278           if( c!='.' && c!='l' ){
 279             done = 1;
 280           }else{
 281             fmt--;
 282           }
 283           break;
 284         }
 285         case '*': {
 286           if( bArgList ){
 287             width = (int)getIntArg(pArgList);
 288           }else{
 289             width = va_arg(ap,int);
 290           }
 291           if( width<0 ){
 292             flag_leftjustify = 1;
 293             width = width >= -2147483647 ? -width : 0;
 294           }
 295 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
 296           if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
 297             width = SQLITE_PRINTF_PRECISION_LIMIT;
 298           }
 299 #endif
 300           if( (c = fmt[1])!='.' && c!='l' ){
 301             c = *++fmt;
 302             done = 1;
 303           }
 304           break;
 305         }
 306         case '.': {
 307           c = *++fmt;
 308           if( c=='*' ){
 309             if( bArgList ){
 310               precision = (int)getIntArg(pArgList);
 311             }else{
 312               precision = va_arg(ap,int);
 313             }
 314             if( precision<0 ){
 315               precision = precision >= -2147483647 ? -precision : -1;
 316             }
 317             c = *++fmt;
 318           }else{
 319             unsigned px = 0;
 320             while( c>='0' && c<='9' ){
 321               px = px*10 + c - '0';
 322               c = *++fmt;
 323             }
 324             testcase( px>0x7fffffff );
 325             precision = px & 0x7fffffff;
 326           }
 327 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
 328           if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
 329             precision = SQLITE_PRINTF_PRECISION_LIMIT;
 330           }
 331 #endif
 332           if( c=='l' ){
 333             --fmt;
 334           }else{
 335             done = 1;
 336           }
 337           break;
 338         }
 339       }
 340     }while( !done && (c=(*++fmt))!=0 );
 341
 342     /* Fetch the info entry for the field */
 343     infop = &fmtinfo[0];
 344     xtype = etINVALID;
 345     for(idx=0; idx<ArraySize(fmtinfo); idx++){
 346       if( c==fmtinfo[idx].fmttype ){
 347         infop = &fmtinfo[idx];
 348         xtype = infop->type;
 349         break;
 350       }
 351     }
 352
 353     /*
 354     ** At this point, variables are initialized as follows:
 355     **
 356     **   flag_alternateform          TRUE if a '#' is present.
 357     **   flag_altform2               TRUE if a '!' is present.
 358     **   flag_prefix                 '+' or ' ' or zero
 359     **   flag_leftjustify            TRUE if a '-' is present or if the
 360     **                               field width was negative.
 361     **   flag_zeropad                TRUE if the width began with 0.
 362     **   flag_long                   1 for "l", 2 for "ll"
 363     **   width                       The specified field width.  This is
 364     **                               always non-negative.  Zero is the default.
 365     **   precision                   The specified precision.  The default
 366     **                               is -1.
 367     **   xtype                       The class of the conversion.
 368     **   infop                       Pointer to the appropriate info struct.
 369     */
 370     assert( width>=0 );
 371     assert( precision>=(-1) );
 372     switch( xtype ){
 373       case etPOINTER:
 374         flag_long = sizeof(char*)==sizeof(i64) ? 2 :
 375                      sizeof(char*)==sizeof(long int) ? 1 : 0;
 376         /* no break */ deliberate_fall_through
 377       case etORDINAL:
 378       case etRADIX:
 379         cThousand = 0;
 380         /* no break */ deliberate_fall_through
 381       case etDECIMAL:
 382         if( infop->flags & FLAG_SIGNED ){
 383           i64 v;
 384           if( bArgList ){
 385             v = getIntArg(pArgList);
 386           }else if( flag_long ){
 387             if( flag_long==2 ){
 388               v = va_arg(ap,i64) ;
 389             }else{
 390               v = va_arg(ap,long int);
 391             }
 392           }else{
 393             v = va_arg(ap,int);
 394           }
 395           if( v<0 ){
 396             testcase( v==SMALLEST_INT64 );
 397             testcase( v==(-1) );
 398             longvalue = ~v;
 399             longvalue++;
 400             prefix = '-';
 401           }else{
 402             longvalue = v;
 403             prefix = flag_prefix;
 404           }
 405         }else{
 406           if( bArgList ){
 407             longvalue = (u64)getIntArg(pArgList);
 408           }else if( flag_long ){
 409             if( flag_long==2 ){
 410               longvalue = va_arg(ap,u64);
 411             }else{
 412               longvalue = va_arg(ap,unsigned long int);
 413             }
 414           }else{
 415             longvalue = va_arg(ap,unsigned int);
 416           }
 417           prefix = 0;
 418         }
 419         if( longvalue==0 ) flag_alternateform = 0;
 420         if( flag_zeropad && precision<width-(prefix!=0) ){
 421           precision = width-(prefix!=0);
 422         }
 423         if( precision<etBUFSIZE-10-etBUFSIZE/3 ){
 424           nOut = etBUFSIZE;
 425           zOut = buf;
 426         }else{
 427           u64 n;
 428           n = (u64)precision + 10;
 429           if( cThousand ) n += precision/3;
 430           zOut = zExtra = printfTempBuf(pAccum, n);
 431           if( zOut==0 ) return;
 432           nOut = (int)n;
 433         }
 434         bufpt = &zOut[nOut-1];
 435         if( xtype==etORDINAL ){
 436           static const char zOrd[] = "thstndrd";
 437           int x = (int)(longvalue % 10);
 438           if( x>=4 || (longvalue/10)%10==1 ){
 439             x = 0;
 440           }
 441           *(--bufpt) = zOrd[x*2+1];
 442           *(--bufpt) = zOrd[x*2];
 443         }
 444         {
 445           const char *cset = &aDigits[infop->charset];
 446           u8 base = infop->base;
 447           do{                                           /* Convert to ascii */
 448             *(--bufpt) = cset[longvalue%base];
 449             longvalue = longvalue/base;
 450           }while( longvalue>0 );
 451         }
 452         length = (int)(&zOut[nOut-1]-bufpt);
 453         while( precision>length ){
 454           *(--bufpt) = '0';                             /* Zero pad */
 455           length++;
 456         }
 457         if( cThousand ){
 458           int nn = (length - 1)/3;  /* Number of "," to insert */
 459           int ix = (length - 1)%3 + 1;
 460           bufpt -= nn;
 461           for(idx=0; nn>0; idx++){
 462             bufpt[idx] = bufpt[idx+nn];
 463             ix--;
 464             if( ix==0 ){
 465               bufpt[++idx] = cThousand;
 466               nn--;
 467               ix = 3;
 468             }
 469           }
 470         }
 471         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
 472         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
 473           const char *pre;
 474           char x;
 475           pre = &aPrefix[infop->prefix];
 476           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
 477         }
 478         length = (int)(&zOut[nOut-1]-bufpt);
 479         break;
 480       case etFLOAT:
 481       case etEXP:
 482       case etGENERIC: {
 483         FpDecode s;
 484         int iRound;
 485         int j;
 486
 487         if( bArgList ){
 488           realvalue = getDoubleArg(pArgList);
 489         }else{
 490           realvalue = va_arg(ap,double);
 491         }
 492         if( precision<0 ) precision = 6;         /* Set default precision */
 493 #ifdef SQLITE_FP_PRECISION_LIMIT
 494         if( precision>SQLITE_FP_PRECISION_LIMIT ){
 495           precision = SQLITE_FP_PRECISION_LIMIT;
 496         }
 497 #endif
 498         if( xtype==etFLOAT ){
 499           iRound = -precision;
 500         }else if( xtype==etGENERIC ){
 501           iRound = precision;
 502         }else{
 503           iRound = precision+1;
 504         }
 505         sqlite3FpDecode(&s, realvalue, iRound, flag_altform2 ? 26 : 16);
 506         if( s.isSpecial ){
 507           if( s.isSpecial==2 ){
 508             bufpt = flag_zeropad ? "null" : "NaN";
 509             length = sqlite3Strlen30(bufpt);
 510             break;
 511           }else if( flag_zeropad ){
 512             s.z[0] = '9';
 513             s.iDP = 1000;
 514             s.n = 1;
 515           }else{
 516             memcpy(buf, "-Inf", 5);
 517             bufpt = buf;
 518             if( s.sign=='-' ){
 519               /* no-op */
 520             }else if( flag_prefix ){
 521               buf[0] = flag_prefix;
 522             }else{
 523               bufpt++;
 524             }
 525             length = sqlite3Strlen30(bufpt);
 526             break;
 527           }
 528         }
 529         if( s.sign=='-' ){
 530           prefix = '-';
 531         }else{
 532           prefix = flag_prefix;
 533         }
 534
 535         exp = s.iDP-1;
 536         if( xtype==etGENERIC && precision>0 ) precision--;
 537
 538         /*
 539         ** If the field type is etGENERIC, then convert to either etEXP
 540         ** or etFLOAT, as appropriate.
 541         */
 542         if( xtype==etGENERIC ){
 543           flag_rtz = !flag_alternateform;
 544           if( exp<-4 || exp>precision ){
 545             xtype = etEXP;
 546           }else{
 547             precision = precision - exp;
 548             xtype = etFLOAT;
 549           }
 550         }else{
 551           flag_rtz = flag_altform2;
 552         }
 553         if( xtype==etEXP ){
 554           e2 = 0;
 555         }else{
 556           e2 = s.iDP - 1;
 557         }
 558         bufpt = buf;
 559         {
 560           i64 szBufNeeded;           /* Size of a temporary buffer needed */
 561           szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;
 562           if( cThousand && e2>0 ) szBufNeeded += (e2+2)/3;
 563           if( szBufNeeded > etBUFSIZE ){
 564             bufpt = zExtra = printfTempBuf(pAccum, szBufNeeded);
 565             if( bufpt==0 ) return;
 566           }
 567         }
 568         zOut = bufpt;
 569         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
 570         /* The sign in front of the number */
 571         if( prefix ){
 572           *(bufpt++) = prefix;
 573         }
 574         /* Digits prior to the decimal point */
 575         j = 0;
 576         if( e2<0 ){
 577           *(bufpt++) = '0';
 578         }else{
 579           for(; e2>=0; e2--){
 580             *(bufpt++) = j<s.n ? s.z[j++] : '0';
 581             if( cThousand && (e2%3)==0 && e2>1 ) *(bufpt++) = ',';
 582           }
 583         }
 584         /* The decimal point */
 585         if( flag_dp ){
 586           *(bufpt++) = '.';
 587         }
 588         /* "0" digits after the decimal point but before the first
 589         ** significant digit of the number */
 590         for(e2++; e2<0 && precision>0; precision--, e2++){
 591           *(bufpt++) = '0';
 592         }
 593         /* Significant digits after the decimal point */
 594         while( (precision--)>0 ){
 595           *(bufpt++) = j<s.n ? s.z[j++] : '0';
 596         }
 597         /* Remove trailing zeros and the "." if no digits follow the "." */
 598         if( flag_rtz && flag_dp ){
 599           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
 600           assert( bufpt>zOut );
 601           if( bufpt[-1]=='.' ){
 602             if( flag_altform2 ){
 603               *(bufpt++) = '0';
 604             }else{
 605               *(--bufpt) = 0;
 606             }
 607           }
 608         }
 609         /* Add the "eNNN" suffix */
 610         if( xtype==etEXP ){
 611           exp = s.iDP - 1;
 612           *(bufpt++) = aDigits[infop->charset];
 613           if( exp<0 ){
 614             *(bufpt++) = '-'; exp = -exp;
 615           }else{
 616             *(bufpt++) = '+';
 617           }
 618           if( exp>=100 ){
 619             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */
 620             exp %= 100;
 621           }
 622           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */
 623           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */
 624         }
 625         *bufpt = 0;
 626
 627         /* The converted number is in buf[] and zero terminated. Output it.
 628         ** Note that the number is in the usual order, not reversed as with
 629         ** integer conversions. */
 630         length = (int)(bufpt-zOut);
 631         bufpt = zOut;
 632
 633         /* Special case:  Add leading zeros if the flag_zeropad flag is
 634         ** set and we are not left justified */
 635         if( flag_zeropad && !flag_leftjustify && length < width){
 636           int i;
 637           int nPad = width - length;
 638           for(i=width; i>=nPad; i--){
 639             bufpt[i] = bufpt[i-nPad];
 640           }
 641           i = prefix!=0;
 642           while( nPad-- ) bufpt[i++] = '0';
 643           length = width;
 644         }
 645         break;
 646       }
 647       case etSIZE:
 648         if( !bArgList ){
 649           *(va_arg(ap,int*)) = pAccum->nChar;
 650         }
 651         length = width = 0;
 652         break;
 653       case etPERCENT:
 654         buf[0] = '%';
 655         bufpt = buf;
 656         length = 1;
 657         break;
 658       case etCHARX:
 659         if( bArgList ){
 660           bufpt = getTextArg(pArgList);
 661           length = 1;
 662           if( bufpt ){
 663             buf[0] = c = *(bufpt++);
 664             if( (c&0xc0)==0xc0 ){
 665               while( length<4 && (bufpt[0]&0xc0)==0x80 ){
 666                 buf[length++] = *(bufpt++);
 667               }
 668             }
 669           }else{
 670             buf[0] = 0;
 671           }
 672         }else{
 673           unsigned int ch = va_arg(ap,unsigned int);
 674           if( ch<0x00080 ){
 675             buf[0] = ch & 0xff;
 676             length = 1;
 677           }else if( ch<0x00800 ){
 678             buf[0] = 0xc0 + (u8)((ch>>6)&0x1f);
 679             buf[1] = 0x80 + (u8)(ch & 0x3f);
 680             length = 2;
 681           }else if( ch<0x10000 ){
 682             buf[0] = 0xe0 + (u8)((ch>>12)&0x0f);
 683             buf[1] = 0x80 + (u8)((ch>>6) & 0x3f);
 684             buf[2] = 0x80 + (u8)(ch & 0x3f);
 685             length = 3;
 686           }else{
 687             buf[0] = 0xf0 + (u8)((ch>>18) & 0x07);
 688             buf[1] = 0x80 + (u8)((ch>>12) & 0x3f);
 689             buf[2] = 0x80 + (u8)((ch>>6) & 0x3f);
 690             buf[3] = 0x80 + (u8)(ch & 0x3f);
 691             length = 4;
 692           }
 693         }
 694         if( precision>1 ){
 695           i64 nPrior = 1;
 696           width -= precision-1;
 697           if( width>1 && !flag_leftjustify ){
 698             sqlite3_str_appendchar(pAccum, width-1, ' ');
 699             width = 0;
 700           }
 701           sqlite3_str_append(pAccum, buf, length);
 702           precision--;
 703           while( precision > 1 ){
 704             i64 nCopyBytes;
 705             if( nPrior > precision-1 ) nPrior = precision - 1;
 706             nCopyBytes = length*nPrior;
 707             if( nCopyBytes + pAccum->nChar >= pAccum->nAlloc ){
 708               sqlite3StrAccumEnlarge(pAccum, nCopyBytes);
 709             }
 710             if( pAccum->accError ) break;
 711             sqlite3_str_append(pAccum,
 712                  &pAccum->zText[pAccum->nChar-nCopyBytes], nCopyBytes);
 713             precision -= nPrior;
 714             nPrior *= 2;
 715           }
 716         }
 717         bufpt = buf;
 718         flag_altform2 = 1;
 719         goto adjust_width_for_utf8;
 720       case etSTRING:
 721       case etDYNSTRING:
 722         if( bArgList ){
 723           bufpt = getTextArg(pArgList);
 724           xtype = etSTRING;
 725         }else{
 726           bufpt = va_arg(ap,char*);
 727         }
 728         if( bufpt==0 ){
 729           bufpt = "";
 730         }else if( xtype==etDYNSTRING ){
 731           if( pAccum->nChar==0
 732            && pAccum->mxAlloc
 733            && width==0
 734            && precision<0
 735            && pAccum->accError==0
 736           ){
 737             /* Special optimization for sqlite3_mprintf("%z..."):
 738             ** Extend an existing memory allocation rather than creating
 739             ** a new one. */
 740             assert( (pAccum->printfFlags&SQLITE_PRINTF_MALLOCED)==0 );
 741             pAccum->zText = bufpt;
 742             pAccum->nAlloc = sqlite3DbMallocSize(pAccum->db, bufpt);
 743             pAccum->nChar = 0x7fffffff & (int)strlen(bufpt);
 744             pAccum->printfFlags |= SQLITE_PRINTF_MALLOCED;
 745             length = 0;
 746             break;
 747           }
 748           zExtra = bufpt;
 749         }
 750         if( precision>=0 ){
 751           if( flag_altform2 ){
 752             /* Set length to the number of bytes needed in order to display
 753             ** precision characters */
 754             unsigned char *z = (unsigned char*)bufpt;
 755             while( precision-- > 0 && z[0] ){
 756               SQLITE_SKIP_UTF8(z);
 757             }
 758             length = (int)(z - (unsigned char*)bufpt);
 759           }else{
 760             for(length=0; length<precision && bufpt[length]; length++){}
 761           }
 762         }else{
 763           length = 0x7fffffff & (int)strlen(bufpt);
 764         }
 765       adjust_width_for_utf8:
 766         if( flag_altform2 && width>0 ){
 767           /* Adjust width to account for extra bytes in UTF-8 characters */
 768           int ii = length - 1;
 769           while( ii>=0 ) if( (bufpt[ii--] & 0xc0)==0x80 ) width++;
 770         }
 771         break;
 772       case etSQLESCAPE:           /* %q: Escape ' characters */
 773       case etSQLESCAPE2:          /* %Q: Escape ' and enclose in '...' */
 774       case etSQLESCAPE3: {        /* %w: Escape " characters */
 775         i64 i, j, k, n;
 776         int needQuote, isnull;
 777         char ch;
 778         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
 779         char *escarg;
 780
 781         if( bArgList ){
 782           escarg = getTextArg(pArgList);
 783         }else{
 784           escarg = va_arg(ap,char*);
 785         }
 786         isnull = escarg==0;
 787         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
 788         /* For %q, %Q, and %w, the precision is the number of bytes (or
 789         ** characters if the ! flags is present) to use from the input.
 790         ** Because of the extra quoting characters inserted, the number
 791         ** of output characters may be larger than the precision.
 792         */
 793         k = precision;
 794         for(i=n=0; k!=0 && (ch=escarg[i])!=0; i++, k--){
 795           if( ch==q )  n++;
 796           if( flag_altform2 && (ch&0xc0)==0xc0 ){
 797             while( (escarg[i+1]&0xc0)==0x80 ){ i++; }
 798           }
 799         }
 800         needQuote = !isnull && xtype==etSQLESCAPE2;
 801         n += i + 3;
 802         if( n>etBUFSIZE ){
 803           bufpt = zExtra = printfTempBuf(pAccum, n);
 804           if( bufpt==0 ) return;
 805         }else{
 806           bufpt = buf;
 807         }
 808         j = 0;
 809         if( needQuote ) bufpt[j++] = q;
 810         k = i;
 811         for(i=0; i<k; i++){
 812           bufpt[j++] = ch = escarg[i];
 813           if( ch==q ) bufpt[j++] = ch;
 814         }
 815         if( needQuote ) bufpt[j++] = q;
 816         bufpt[j] = 0;
 817         length = j;
 818         goto adjust_width_for_utf8;
 819       }
 820       case etTOKEN: {
 821         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
 822         if( flag_alternateform ){
 823           /* %#T means an Expr pointer that uses Expr.u.zToken */
 824           Expr *pExpr = va_arg(ap,Expr*);
 825           if( ALWAYS(pExpr) && ALWAYS(!ExprHasProperty(pExpr,EP_IntValue)) ){
 826             sqlite3_str_appendall(pAccum, (const char*)pExpr->u.zToken);
 827             sqlite3RecordErrorOffsetOfExpr(pAccum->db, pExpr);
 828           }
 829         }else{
 830           /* %T means a Token pointer */
 831           Token *pToken = va_arg(ap, Token*);
 832           assert( bArgList==0 );
 833           if( pToken && pToken->n ){
 834             sqlite3_str_append(pAccum, (const char*)pToken->z, pToken->n);
 835             sqlite3RecordErrorByteOffset(pAccum->db, pToken->z);
 836           }
 837         }
 838         length = width = 0;
 839         break;
 840       }
 841       case etSRCITEM: {
 842         SrcItem *pItem;
 843         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
 844         pItem = va_arg(ap, SrcItem*);
 845         assert( bArgList==0 );
 846         if( pItem->zAlias && !flag_altform2 ){
 847           sqlite3_str_appendall(pAccum, pItem->zAlias);
 848         }else if( pItem->zName ){
 849           if( pItem->zDatabase ){
 850             sqlite3_str_appendall(pAccum, pItem->zDatabase);
 851             sqlite3_str_append(pAccum, ".", 1);
 852           }
 853           sqlite3_str_appendall(pAccum, pItem->zName);
 854         }else if( pItem->zAlias ){
 855           sqlite3_str_appendall(pAccum, pItem->zAlias);
 856         }else{
 857           Select *pSel = pItem->pSelect;
 858           assert( pSel!=0 );
 859           if( pSel->selFlags & SF_NestedFrom ){
 860             sqlite3_str_appendf(pAccum, "(join-%u)", pSel->selId);
 861           }else{
 862             sqlite3_str_appendf(pAccum, "(subquery-%u)", pSel->selId);
 863           }
 864         }
 865         length = width = 0;
 866         break;
 867       }
 868       default: {
 869         assert( xtype==etINVALID );
 870         return;
 871       }
 872     }/* End switch over the format type */
 873     /*
 874     ** The text of the conversion is pointed to by "bufpt" and is
 875     ** "length" characters long.  The field width is "width".  Do
 876     ** the output.  Both length and width are in bytes, not characters,
 877     ** at this point.  If the "!" flag was present on string conversions
 878     ** indicating that width and precision should be expressed in characters,
 879     ** then the values have been translated prior to reaching this point.
 880     */
 881     width -= length;
 882     if( width>0 ){
 883       if( !flag_leftjustify ) sqlite3_str_appendchar(pAccum, width, ' ');
 884       sqlite3_str_append(pAccum, bufpt, length);
 885       if( flag_leftjustify ) sqlite3_str_appendchar(pAccum, width, ' ');
 886     }else{
 887       sqlite3_str_append(pAccum, bufpt, length);
 888     }
 889
 890     if( zExtra ){
 891       sqlite3DbFree(pAccum->db, zExtra);
 892       zExtra = 0;
 893     }
 894   }/* End for loop over the format string */
 895 } /* End of function */
 896
 897
 898 /*
 899 ** The z string points to the first character of a token that is
 900 ** associated with an error.  If db does not already have an error
 901 ** byte offset recorded, try to compute the error byte offset for
 902 ** z and set the error byte offset in db.
 903 */
 904 void sqlite3RecordErrorByteOffset(sqlite3 *db, const char *z){
 905   const Parse *pParse;
 906   const char *zText;
 907   const char *zEnd;
 908   assert( z!=0 );
 909   if( NEVER(db==0) ) return;
 910   if( db->errByteOffset!=(-2) ) return;
 911   pParse = db->pParse;
 912   if( NEVER(pParse==0) ) return;
 913   zText =pParse->zTail;
 914   if( NEVER(zText==0) ) return;
 915   zEnd = &zText[strlen(zText)];
 916   if( SQLITE_WITHIN(z,zText,zEnd) ){
 917     db->errByteOffset = (int)(z-zText);
 918   }
 919 }
 920
 921 /*
 922 ** If pExpr has a byte offset for the start of a token, record that as
 923 ** as the error offset.
 924 */
 925 void sqlite3RecordErrorOffsetOfExpr(sqlite3 *db, const Expr *pExpr){
 926   while( pExpr
 927      && (ExprHasProperty(pExpr,EP_OuterON|EP_InnerON) || pExpr->w.iOfst<=0)
 928   ){
 929     pExpr = pExpr->pLeft;
 930   }
 931   if( pExpr==0 ) return;
 932   db->errByteOffset = pExpr->w.iOfst;
 933 }
 934
 935 /*
 936 ** Enlarge the memory allocation on a StrAccum object so that it is
 937 ** able to accept at least N more bytes of text.
 938 **
 939 ** Return the number of bytes of text that StrAccum is able to accept
 940 ** after the attempted enlargement.  The value returned might be zero.
 941 */
 942 int sqlite3StrAccumEnlarge(StrAccum *p, i64 N){
 943   char *zNew;
 944   assert( p->nChar+N >= p->nAlloc ); /* Only called if really needed */
 945   if( p->accError ){
 946     testcase(p->accError==SQLITE_TOOBIG);
 947     testcase(p->accError==SQLITE_NOMEM);
 948     return 0;
 949   }
 950   if( p->mxAlloc==0 ){
 951     sqlite3StrAccumSetError(p, SQLITE_TOOBIG);
 952     return p->nAlloc - p->nChar - 1;
 953   }else{
 954     char *zOld = isMalloced(p) ? p->zText : 0;
 955     i64 szNew = p->nChar + N + 1;
 956     if( szNew+p->nChar<=p->mxAlloc ){
 957       /* Force exponential buffer size growth as long as it does not overflow,
 958       ** to avoid having to call this routine too often */
 959       szNew += p->nChar;
 960     }
 961     if( szNew > p->mxAlloc ){
 962       sqlite3_str_reset(p);
 963       sqlite3StrAccumSetError(p, SQLITE_TOOBIG);
 964       return 0;
 965     }else{
 966       p->nAlloc = (int)szNew;
 967     }
 968     if( p->db ){
 969       zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
 970     }else{
 971       zNew = sqlite3Realloc(zOld, p->nAlloc);
 972     }
 973     if( zNew ){
 974       assert( p->zText!=0 || p->nChar==0 );
 975       if( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
 976       p->zText = zNew;
 977       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
 978       p->printfFlags |= SQLITE_PRINTF_MALLOCED;
 979     }else{
 980       sqlite3_str_reset(p);
 981       sqlite3StrAccumSetError(p, SQLITE_NOMEM);
 982       return 0;
 983     }
 984   }
 985   assert( N>=0 && N<=0x7fffffff );
 986   return (int)N;
 987 }
 988
 989 /*
 990 ** Append N copies of character c to the given string buffer.
 991 */
 992 void sqlite3_str_appendchar(sqlite3_str *p, int N, char c){
 993   testcase( p->nChar + (i64)N > 0x7fffffff );
 994   if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
 995     return;
 996   }
 997   while( (N--)>0 ) p->zText[p->nChar++] = c;
 998 }
 999
1000 /*
1001 ** The StrAccum "p" is not large enough to accept N new bytes of z[].
1002 ** So enlarge if first, then do the append.
1003 **
1004 ** This is a helper routine to sqlite3_str_append() that does special-case
1005 ** work (enlarging the buffer) using tail recursion, so that the
1006 ** sqlite3_str_append() routine can use fast calling semantics.
1007 */
1008 static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
1009   N = sqlite3StrAccumEnlarge(p, N);
1010   if( N>0 ){
1011     memcpy(&p->zText[p->nChar], z, N);
1012     p->nChar += N;
1013   }
1014 }
1015
1016 /*
1017 ** Append N bytes of text from z to the StrAccum object.  Increase the
1018 ** size of the memory allocation for StrAccum if necessary.
1019 */
1020 void sqlite3_str_append(sqlite3_str *p, const char *z, int N){
1021   assert( z!=0 || N==0 );
1022   assert( p->zText!=0 || p->nChar==0 || p->accError );
1023   assert( N>=0 );
1024   assert( p->accError==0 || p->nAlloc==0 || p->mxAlloc==0 );
1025   if( p->nChar+N >= p->nAlloc ){
1026     enlargeAndAppend(p,z,N);
1027   }else if( N ){
1028     assert( p->zText );
1029     p->nChar += N;
1030     memcpy(&p->zText[p->nChar-N], z, N);
1031   }
1032 }
1033
1034 /*
1035 ** Append the complete text of zero-terminated string z[] to the p string.
1036 */
1037 void sqlite3_str_appendall(sqlite3_str *p, const char *z){
1038   sqlite3_str_append(p, z, sqlite3Strlen30(z));
1039 }
1040
1041
1042 /*
1043 ** Finish off a string by making sure it is zero-terminated.
1044 ** Return a pointer to the resulting string.  Return a NULL
1045 ** pointer if any kind of error was encountered.
1046 */
1047 static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){
1048   char *zText;
1049   assert( p->mxAlloc>0 && !isMalloced(p) );
1050   zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
1051   if( zText ){
1052     memcpy(zText, p->zText, p->nChar+1);
1053     p->printfFlags |= SQLITE_PRINTF_MALLOCED;
1054   }else{
1055     sqlite3StrAccumSetError(p, SQLITE_NOMEM);
1056   }
1057   p->zText = zText;
1058   return zText;
1059 }
1060 char *sqlite3StrAccumFinish(StrAccum *p){
1061   if( p->zText ){
1062     p->zText[p->nChar] = 0;
1063     if( p->mxAlloc>0 && !isMalloced(p) ){
1064       return strAccumFinishRealloc(p);
1065     }
1066   }
1067   return p->zText;
1068 }
1069
1070 /*
1071 ** Use the content of the StrAccum passed as the second argument
1072 ** as the result of an SQL function.
1073 */
1074 void sqlite3ResultStrAccum(sqlite3_context *pCtx, StrAccum *p){
1075   if( p->accError ){
1076     sqlite3_result_error_code(pCtx, p->accError);
1077     sqlite3_str_reset(p);
1078   }else if( isMalloced(p) ){
1079     sqlite3_result_text(pCtx, p->zText, p->nChar, SQLITE_DYNAMIC);
1080   }else{
1081     sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
1082     sqlite3_str_reset(p);
1083   }
1084 }
1085
1086 /*
1087 ** This singleton is an sqlite3_str object that is returned if
1088 ** sqlite3_malloc() fails to provide space for a real one.  This
1089 ** sqlite3_str object accepts no new text and always returns
1090 ** an SQLITE_NOMEM error.
1091 */
1092 static sqlite3_str sqlite3OomStr = {
1093    0, 0, 0, 0, 0, SQLITE_NOMEM, 0
1094 };
1095
1096 /* Finalize a string created using sqlite3_str_new().
1097 */
1098 char *sqlite3_str_finish(sqlite3_str *p){
1099   char *z;
1100   if( p!=0 && p!=&sqlite3OomStr ){
1101     z = sqlite3StrAccumFinish(p);
1102     sqlite3_free(p);
1103   }else{
1104     z = 0;
1105   }
1106   return z;
1107 }
1108
1109 /* Return any error code associated with p */
1110 int sqlite3_str_errcode(sqlite3_str *p){
1111   return p ? p->accError : SQLITE_NOMEM;
1112 }
1113
1114 /* Return the current length of p in bytes */
1115 int sqlite3_str_length(sqlite3_str *p){
1116   return p ? p->nChar : 0;
1117 }
1118
1119 /* Return the current value for p */
1120 char *sqlite3_str_value(sqlite3_str *p){
1121   if( p==0 || p->nChar==0 ) return 0;
1122   p->zText[p->nChar] = 0;
1123   return p->zText;
1124 }
1125
1126 /*
1127 ** Reset an StrAccum string.  Reclaim all malloced memory.
1128 */
1129 void sqlite3_str_reset(StrAccum *p){
1130   if( isMalloced(p) ){
1131     sqlite3DbFree(p->db, p->zText);
1132     p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;
1133   }
1134   p->nAlloc = 0;
1135   p->nChar = 0;
1136   p->zText = 0;
1137 }
1138
1139 /*
1140 ** Initialize a string accumulator.
1141 **
1142 ** p:     The accumulator to be initialized.
1143 ** db:    Pointer to a database connection.  May be NULL.  Lookaside
1144 **        memory is used if not NULL. db->mallocFailed is set appropriately
1145 **        when not NULL.
1146 ** zBase: An initial buffer.  May be NULL in which case the initial buffer
1147 **        is malloced.
1148 ** n:     Size of zBase in bytes.  If total space requirements never exceed
1149 **        n then no memory allocations ever occur.
1150 ** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
1151 **        allocations will ever occur.
1152 */
1153 void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
1154   p->zText = zBase;
1155   p->db = db;
1156   p->nAlloc = n;
1157   p->mxAlloc = mx;
1158   p->nChar = 0;
1159   p->accError = 0;
1160   p->printfFlags = 0;
1161 }
1162
1163 /* Allocate and initialize a new dynamic string object */
1164 sqlite3_str *sqlite3_str_new(sqlite3 *db){
1165   sqlite3_str *p = sqlite3_malloc64(sizeof(*p));
1166   if( p ){
1167     sqlite3StrAccumInit(p, 0, 0, 0,
1168             db ? db->aLimit[SQLITE_LIMIT_LENGTH] : SQLITE_MAX_LENGTH);
1169   }else{
1170     p = &sqlite3OomStr;
1171   }
1172   return p;
1173 }
1174
1175 /*
1176 ** Print into memory obtained from sqliteMalloc().  Use the internal
1177 ** %-conversion extensions.
1178 */
1179 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
1180   char *z;
1181   char zBase[SQLITE_PRINT_BUF_SIZE];
1182   StrAccum acc;
1183   assert( db!=0 );
1184   sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
1185                       db->aLimit[SQLITE_LIMIT_LENGTH]);
1186   acc.printfFlags = SQLITE_PRINTF_INTERNAL;
1187   sqlite3_str_vappendf(&acc, zFormat, ap);
1188   z = sqlite3StrAccumFinish(&acc);
1189   if( acc.accError==SQLITE_NOMEM ){
1190     sqlite3OomFault(db);
1191   }
1192   return z;
1193 }
1194
1195 /*
1196 ** Print into memory obtained from sqliteMalloc().  Use the internal
1197 ** %-conversion extensions.
1198 */
1199 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
1200   va_list ap;
1201   char *z;
1202   va_start(ap, zFormat);
1203   z = sqlite3VMPrintf(db, zFormat, ap);
1204   va_end(ap);
1205   return z;
1206 }
1207
1208 /*
1209 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
1210 ** %-conversion extensions.
1211 */
1212 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
1213   char *z;
1214   char zBase[SQLITE_PRINT_BUF_SIZE];
1215   StrAccum acc;
1216
1217 #ifdef SQLITE_ENABLE_API_ARMOR
1218   if( zFormat==0 ){
1219     (void)SQLITE_MISUSE_BKPT;
1220     return 0;
1221   }
1222 #endif
1223 #ifndef SQLITE_OMIT_AUTOINIT
1224   if( sqlite3_initialize() ) return 0;
1225 #endif
1226   sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
1227   sqlite3_str_vappendf(&acc, zFormat, ap);
1228   z = sqlite3StrAccumFinish(&acc);
1229   return z;
1230 }
1231
1232 /*
1233 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
1234 ** %-conversion extensions.
1235 */
1236 char *sqlite3_mprintf(const char *zFormat, ...){
1237   va_list ap;
1238   char *z;
1239 #ifndef SQLITE_OMIT_AUTOINIT
1240   if( sqlite3_initialize() ) return 0;
1241 #endif
1242   va_start(ap, zFormat);
1243   z = sqlite3_vmprintf(zFormat, ap);
1244   va_end(ap);
1245   return z;
1246 }
1247
1248 /*
1249 ** sqlite3_snprintf() works like snprintf() except that it ignores the
1250 ** current locale settings.  This is important for SQLite because we
1251 ** are not able to use a "," as the decimal point in place of "." as
1252 ** specified by some locales.
1253 **
1254 ** Oops:  The first two arguments of sqlite3_snprintf() are backwards
1255 ** from the snprintf() standard.  Unfortunately, it is too late to change
1256 ** this without breaking compatibility, so we just have to live with the
1257 ** mistake.
1258 **
1259 ** sqlite3_vsnprintf() is the varargs version.
1260 */
1261 char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
1262   StrAccum acc;
1263   if( n<=0 ) return zBuf;
1264 #ifdef SQLITE_ENABLE_API_ARMOR
1265   if( zBuf==0 || zFormat==0 ) {
1266     (void)SQLITE_MISUSE_BKPT;
1267     if( zBuf ) zBuf[0] = 0;
1268     return zBuf;
1269   }
1270 #endif
1271   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
1272   sqlite3_str_vappendf(&acc, zFormat, ap);
1273   zBuf[acc.nChar] = 0;
1274   return zBuf;
1275 }
1276 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
1277   StrAccum acc;
1278   va_list ap;
1279   if( n<=0 ) return zBuf;
1280 #ifdef SQLITE_ENABLE_API_ARMOR
1281   if( zBuf==0 || zFormat==0 ) {
1282     (void)SQLITE_MISUSE_BKPT;
1283     if( zBuf ) zBuf[0] = 0;
1284     return zBuf;
1285   }
1286 #endif
1287   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
1288   va_start(ap,zFormat);
1289   sqlite3_str_vappendf(&acc, zFormat, ap);
1290   va_end(ap);
1291   zBuf[acc.nChar] = 0;
1292   return zBuf;
1293 }
1294
1295 /*
1296 ** This is the routine that actually formats the sqlite3_log() message.
1297 ** We house it in a separate routine from sqlite3_log() to avoid using
1298 ** stack space on small-stack systems when logging is disabled.
1299 **
1300 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
1301 ** allocate memory because it might be called while the memory allocator
1302 ** mutex is held.
1303 **
1304 ** sqlite3_str_vappendf() might ask for *temporary* memory allocations for
1305 ** certain format characters (%q) or for very large precisions or widths.
1306 ** Care must be taken that any sqlite3_log() calls that occur while the
1307 ** memory mutex is held do not use these mechanisms.
1308 */
1309 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
1310   StrAccum acc;                          /* String accumulator */
1311   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
1312
1313   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
1314   sqlite3_str_vappendf(&acc, zFormat, ap);
1315   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
1316                            sqlite3StrAccumFinish(&acc));
1317 }
1318
1319 /*
1320 ** Format and write a message to the log if logging is enabled.
1321 */
1322 void sqlite3_log(int iErrCode, const char *zFormat, ...){
1323   va_list ap;                             /* Vararg list */
1324   if( sqlite3GlobalConfig.xLog ){
1325     va_start(ap, zFormat);
1326     renderLogMsg(iErrCode, zFormat, ap);
1327     va_end(ap);
1328   }
1329 }
1330
1331 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
1332 /*
1333 ** A version of printf() that understands %lld.  Used for debugging.
1334 ** The printf() built into some versions of windows does not understand %lld
1335 ** and segfaults if you give it a long long int.
1336 */
1337 void sqlite3DebugPrintf(const char *zFormat, ...){
1338   va_list ap;
1339   StrAccum acc;
1340   char zBuf[SQLITE_PRINT_BUF_SIZE*10];
1341   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
1342   va_start(ap,zFormat);
1343   sqlite3_str_vappendf(&acc, zFormat, ap);
1344   va_end(ap);
1345   sqlite3StrAccumFinish(&acc);
1346 #ifdef SQLITE_OS_TRACE_PROC
1347   {
1348     extern void SQLITE_OS_TRACE_PROC(const char *zBuf, int nBuf);
1349     SQLITE_OS_TRACE_PROC(zBuf, sizeof(zBuf));
1350   }
1351 #else
1352   fprintf(stdout,"%s", zBuf);
1353   fflush(stdout);
1354 #endif
1355 }
1356 #endif
1357
1358
1359 /*
1360 ** variable-argument wrapper around sqlite3_str_vappendf(). The bFlags argument
1361 ** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
1362 */
1363 void sqlite3_str_appendf(StrAccum *p, const char *zFormat, ...){
1364   va_list ap;
1365   va_start(ap,zFormat);
1366   sqlite3_str_vappendf(p, zFormat, ap);
1367   va_end(ap);
1368 }
1369
1370
1371 /*****************************************************************************
1372 ** Reference counted string/blob storage
1373 *****************************************************************************/
1374
1375 /*
1376 ** Increase the reference count of the string by one.
1377 **
1378 ** The input parameter is returned.
1379 */
1380 char *sqlite3RCStrRef(char *z){
1381   RCStr *p = (RCStr*)z;
1382   assert( p!=0 );
1383   p--;
1384   p->nRCRef++;
1385   return z;
1386 }
1387
1388 /*
1389 ** Decrease the reference count by one.  Free the string when the
1390 ** reference count reaches zero.
1391 */
1392 void sqlite3RCStrUnref(void *z){
1393   RCStr *p = (RCStr*)z;
1394   assert( p!=0 );
1395   p--;
1396   assert( p->nRCRef>0 );
1397   if( p->nRCRef>=2 ){
1398     p->nRCRef--;
1399   }else{
1400     sqlite3_free(p);
1401   }
1402 }
1403
1404 /*
1405 ** Create a new string that is capable of holding N bytes of text, not counting
1406 ** the zero byte at the end.  The string is uninitialized.
1407 **
1408 ** The reference count is initially 1.  Call sqlite3RCStrUnref() to free the
1409 ** newly allocated string.
1410 **
1411 ** This routine returns 0 on an OOM.
1412 */
1413 char *sqlite3RCStrNew(u64 N){
1414   RCStr *p = sqlite3_malloc64( N + sizeof(*p) + 1 );
1415   if( p==0 ) return 0;
1416   p->nRCRef = 1;
1417   return (char*)&p[1];
1418 }
1419
1420 /*
1421 ** Change the size of the string so that it is able to hold N bytes.
1422 ** The string might be reallocated, so return the new allocation.
1423 */
1424 char *sqlite3RCStrResize(char *z, u64 N){
1425   RCStr *p = (RCStr*)z;
1426   RCStr *pNew;
1427   assert( p!=0 );
1428   p--;
1429   assert( p->nRCRef==1 );
1430   pNew = sqlite3_realloc64(p, N+sizeof(RCStr)+1);
1431   if( pNew==0 ){
1432     sqlite3_free(p);
1433     return 0;
1434   }else{
1435     return (char*)&pNew[1];
1436   }
1437 }