xref: /sqlite-3.40.0/src/printf.c (revision 74bbd37d)
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 etSRCLIST    12 /* a pointer to a SrcList */
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, etSRCLIST,    0,  0 },
99   {  'r', 10, 1, etORDINAL,    0,  0 },
100 };
101 
102 /* Floating point constants used for rounding */
103 static const double arRound[] = {
104   5.0e-01, 5.0e-02, 5.0e-03, 5.0e-04, 5.0e-05,
105   5.0e-06, 5.0e-07, 5.0e-08, 5.0e-09, 5.0e-10,
106 };
107 
108 /*
109 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
110 ** conversions will work.
111 */
112 #ifndef SQLITE_OMIT_FLOATING_POINT
113 /*
114 ** "*val" is a double such that 0.1 <= *val < 10.0
115 ** Return the ascii code for the leading digit of *val, then
116 ** multiply "*val" by 10.0 to renormalize.
117 **
118 ** Example:
119 **     input:     *val = 3.14159
120 **     output:    *val = 1.4159    function return = '3'
121 **
122 ** The counter *cnt is incremented each time.  After counter exceeds
123 ** 16 (the number of significant digits in a 64-bit float) '0' is
124 ** always returned.
125 */
126 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
127   int digit;
128   LONGDOUBLE_TYPE d;
129   if( (*cnt)<=0 ) return '0';
130   (*cnt)--;
131   digit = (int)*val;
132   d = digit;
133   digit += '0';
134   *val = (*val - d)*10.0;
135   return (char)digit;
136 }
137 #endif /* SQLITE_OMIT_FLOATING_POINT */
138 
139 /*
140 ** Set the StrAccum object to an error mode.
141 */
142 static void setStrAccumError(StrAccum *p, u8 eError){
143   assert( eError==SQLITE_NOMEM || eError==SQLITE_TOOBIG );
144   p->accError = eError;
145   if( p->mxAlloc ) sqlite3_str_reset(p);
146   if( eError==SQLITE_TOOBIG ) sqlite3ErrorToParser(p->db, eError);
147 }
148 
149 /*
150 ** Extra argument values from a PrintfArguments object
151 */
152 static sqlite3_int64 getIntArg(PrintfArguments *p){
153   if( p->nArg<=p->nUsed ) return 0;
154   return sqlite3_value_int64(p->apArg[p->nUsed++]);
155 }
156 static double getDoubleArg(PrintfArguments *p){
157   if( p->nArg<=p->nUsed ) return 0.0;
158   return sqlite3_value_double(p->apArg[p->nUsed++]);
159 }
160 static char *getTextArg(PrintfArguments *p){
161   if( p->nArg<=p->nUsed ) return 0;
162   return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
163 }
164 
165 /*
166 ** Allocate memory for a temporary buffer needed for printf rendering.
167 **
168 ** If the requested size of the temp buffer is larger than the size
169 ** of the output buffer in pAccum, then cause an SQLITE_TOOBIG error.
170 ** Do the size check before the memory allocation to prevent rogue
171 ** SQL from requesting large allocations using the precision or width
172 ** field of the printf() function.
173 */
174 static char *printfTempBuf(sqlite3_str *pAccum, sqlite3_int64 n){
175   char *z;
176   if( pAccum->accError ) return 0;
177   if( n>pAccum->nAlloc && n>pAccum->mxAlloc ){
178     setStrAccumError(pAccum, SQLITE_TOOBIG);
179     return 0;
180   }
181   z = sqlite3DbMallocRaw(pAccum->db, n);
182   if( z==0 ){
183     setStrAccumError(pAccum, SQLITE_NOMEM);
184   }
185   return z;
186 }
187 
188 /*
189 ** On machines with a small stack size, you can redefine the
190 ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
191 */
192 #ifndef SQLITE_PRINT_BUF_SIZE
193 # define SQLITE_PRINT_BUF_SIZE 70
194 #endif
195 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
196 
197 /*
198 ** Hard limit on the precision of floating-point conversions.
199 */
200 #ifndef SQLITE_PRINTF_PRECISION_LIMIT
201 # define SQLITE_FP_PRECISION_LIMIT 100000000
202 #endif
203 
204 /*
205 ** Render a string given by "fmt" into the StrAccum object.
206 */
207 void sqlite3_str_vappendf(
208   sqlite3_str *pAccum,       /* Accumulate results here */
209   const char *fmt,           /* Format string */
210   va_list ap                 /* arguments */
211 ){
212   int c;                     /* Next character in the format string */
213   char *bufpt;               /* Pointer to the conversion buffer */
214   int precision;             /* Precision of the current field */
215   int length;                /* Length of the field */
216   int idx;                   /* A general purpose loop counter */
217   int width;                 /* Width of the current field */
218   etByte flag_leftjustify;   /* True if "-" flag is present */
219   etByte flag_prefix;        /* '+' or ' ' or 0 for prefix */
220   etByte flag_alternateform; /* True if "#" flag is present */
221   etByte flag_altform2;      /* True if "!" flag is present */
222   etByte flag_zeropad;       /* True if field width constant starts with zero */
223   etByte flag_long;          /* 1 for the "l" flag, 2 for "ll", 0 by default */
224   etByte done;               /* Loop termination flag */
225   etByte cThousand;          /* Thousands separator for %d and %u */
226   etByte xtype = etINVALID;  /* Conversion paradigm */
227   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
228   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
229   sqlite_uint64 longvalue;   /* Value for integer types */
230   LONGDOUBLE_TYPE realvalue; /* Value for real types */
231   const et_info *infop;      /* Pointer to the appropriate info structure */
232   char *zOut;                /* Rendering buffer */
233   int nOut;                  /* Size of the rendering buffer */
234   char *zExtra = 0;          /* Malloced memory used by some conversion */
235 #ifndef SQLITE_OMIT_FLOATING_POINT
236   int  exp, e2;              /* exponent of real numbers */
237   int nsd;                   /* Number of significant digits returned */
238   double rounder;            /* Used for rounding floating point values */
239   etByte flag_dp;            /* True if decimal point should be shown */
240   etByte flag_rtz;           /* True if trailing zeros should be removed */
241 #endif
242   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
243   char buf[etBUFSIZE];       /* Conversion buffer */
244 
245   /* pAccum never starts out with an empty buffer that was obtained from
246   ** malloc().  This precondition is required by the mprintf("%z...")
247   ** optimization. */
248   assert( pAccum->nChar>0 || (pAccum->printfFlags&SQLITE_PRINTF_MALLOCED)==0 );
249 
250   bufpt = 0;
251   if( (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC)!=0 ){
252     pArgList = va_arg(ap, PrintfArguments*);
253     bArgList = 1;
254   }else{
255     bArgList = 0;
256   }
257   for(; (c=(*fmt))!=0; ++fmt){
258     if( c!='%' ){
259       bufpt = (char *)fmt;
260 #if HAVE_STRCHRNUL
261       fmt = strchrnul(fmt, '%');
262 #else
263       do{ fmt++; }while( *fmt && *fmt != '%' );
264 #endif
265       sqlite3_str_append(pAccum, bufpt, (int)(fmt - bufpt));
266       if( *fmt==0 ) break;
267     }
268     if( (c=(*++fmt))==0 ){
269       sqlite3_str_append(pAccum, "%", 1);
270       break;
271     }
272     /* Find out what flags are present */
273     flag_leftjustify = flag_prefix = cThousand =
274      flag_alternateform = flag_altform2 = flag_zeropad = 0;
275     done = 0;
276     width = 0;
277     flag_long = 0;
278     precision = -1;
279     do{
280       switch( c ){
281         case '-':   flag_leftjustify = 1;     break;
282         case '+':   flag_prefix = '+';        break;
283         case ' ':   flag_prefix = ' ';        break;
284         case '#':   flag_alternateform = 1;   break;
285         case '!':   flag_altform2 = 1;        break;
286         case '0':   flag_zeropad = 1;         break;
287         case ',':   cThousand = ',';          break;
288         default:    done = 1;                 break;
289         case 'l': {
290           flag_long = 1;
291           c = *++fmt;
292           if( c=='l' ){
293             c = *++fmt;
294             flag_long = 2;
295           }
296           done = 1;
297           break;
298         }
299         case '1': case '2': case '3': case '4': case '5':
300         case '6': case '7': case '8': case '9': {
301           unsigned wx = c - '0';
302           while( (c = *++fmt)>='0' && c<='9' ){
303             wx = wx*10 + c - '0';
304           }
305           testcase( wx>0x7fffffff );
306           width = wx & 0x7fffffff;
307 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
308           if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
309             width = SQLITE_PRINTF_PRECISION_LIMIT;
310           }
311 #endif
312           if( c!='.' && c!='l' ){
313             done = 1;
314           }else{
315             fmt--;
316           }
317           break;
318         }
319         case '*': {
320           if( bArgList ){
321             width = (int)getIntArg(pArgList);
322           }else{
323             width = va_arg(ap,int);
324           }
325           if( width<0 ){
326             flag_leftjustify = 1;
327             width = width >= -2147483647 ? -width : 0;
328           }
329 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
330           if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
331             width = SQLITE_PRINTF_PRECISION_LIMIT;
332           }
333 #endif
334           if( (c = fmt[1])!='.' && c!='l' ){
335             c = *++fmt;
336             done = 1;
337           }
338           break;
339         }
340         case '.': {
341           c = *++fmt;
342           if( c=='*' ){
343             if( bArgList ){
344               precision = (int)getIntArg(pArgList);
345             }else{
346               precision = va_arg(ap,int);
347             }
348             if( precision<0 ){
349               precision = precision >= -2147483647 ? -precision : -1;
350             }
351             c = *++fmt;
352           }else{
353             unsigned px = 0;
354             while( c>='0' && c<='9' ){
355               px = px*10 + c - '0';
356               c = *++fmt;
357             }
358             testcase( px>0x7fffffff );
359             precision = px & 0x7fffffff;
360           }
361 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
362           if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
363             precision = SQLITE_PRINTF_PRECISION_LIMIT;
364           }
365 #endif
366           if( c=='l' ){
367             --fmt;
368           }else{
369             done = 1;
370           }
371           break;
372         }
373       }
374     }while( !done && (c=(*++fmt))!=0 );
375 
376     /* Fetch the info entry for the field */
377     infop = &fmtinfo[0];
378     xtype = etINVALID;
379     for(idx=0; idx<ArraySize(fmtinfo); idx++){
380       if( c==fmtinfo[idx].fmttype ){
381         infop = &fmtinfo[idx];
382         xtype = infop->type;
383         break;
384       }
385     }
386 
387     /*
388     ** At this point, variables are initialized as follows:
389     **
390     **   flag_alternateform          TRUE if a '#' is present.
391     **   flag_altform2               TRUE if a '!' is present.
392     **   flag_prefix                 '+' or ' ' or zero
393     **   flag_leftjustify            TRUE if a '-' is present or if the
394     **                               field width was negative.
395     **   flag_zeropad                TRUE if the width began with 0.
396     **   flag_long                   1 for "l", 2 for "ll"
397     **   width                       The specified field width.  This is
398     **                               always non-negative.  Zero is the default.
399     **   precision                   The specified precision.  The default
400     **                               is -1.
401     **   xtype                       The class of the conversion.
402     **   infop                       Pointer to the appropriate info struct.
403     */
404     assert( width>=0 );
405     assert( precision>=(-1) );
406     switch( xtype ){
407       case etPOINTER:
408         flag_long = sizeof(char*)==sizeof(i64) ? 2 :
409                      sizeof(char*)==sizeof(long int) ? 1 : 0;
410         /* Fall through into the next case */
411       case etORDINAL:
412       case etRADIX:
413         cThousand = 0;
414         /* Fall through into the next case */
415       case etDECIMAL:
416         if( infop->flags & FLAG_SIGNED ){
417           i64 v;
418           if( bArgList ){
419             v = getIntArg(pArgList);
420           }else if( flag_long ){
421             if( flag_long==2 ){
422               v = va_arg(ap,i64) ;
423             }else{
424               v = va_arg(ap,long int);
425             }
426           }else{
427             v = va_arg(ap,int);
428           }
429           if( v<0 ){
430             if( v==SMALLEST_INT64 ){
431               longvalue = ((u64)1)<<63;
432             }else{
433               longvalue = -v;
434             }
435             prefix = '-';
436           }else{
437             longvalue = v;
438             prefix = flag_prefix;
439           }
440         }else{
441           if( bArgList ){
442             longvalue = (u64)getIntArg(pArgList);
443           }else if( flag_long ){
444             if( flag_long==2 ){
445               longvalue = va_arg(ap,u64);
446             }else{
447               longvalue = va_arg(ap,unsigned long int);
448             }
449           }else{
450             longvalue = va_arg(ap,unsigned int);
451           }
452           prefix = 0;
453         }
454         if( longvalue==0 ) flag_alternateform = 0;
455         if( flag_zeropad && precision<width-(prefix!=0) ){
456           precision = width-(prefix!=0);
457         }
458         if( precision<etBUFSIZE-10-etBUFSIZE/3 ){
459           nOut = etBUFSIZE;
460           zOut = buf;
461         }else{
462           u64 n;
463           n = (u64)precision + 10;
464           if( cThousand ) n += precision/3;
465           zOut = zExtra = printfTempBuf(pAccum, n);
466           if( zOut==0 ) return;
467           nOut = (int)n;
468         }
469         bufpt = &zOut[nOut-1];
470         if( xtype==etORDINAL ){
471           static const char zOrd[] = "thstndrd";
472           int x = (int)(longvalue % 10);
473           if( x>=4 || (longvalue/10)%10==1 ){
474             x = 0;
475           }
476           *(--bufpt) = zOrd[x*2+1];
477           *(--bufpt) = zOrd[x*2];
478         }
479         {
480           const char *cset = &aDigits[infop->charset];
481           u8 base = infop->base;
482           do{                                           /* Convert to ascii */
483             *(--bufpt) = cset[longvalue%base];
484             longvalue = longvalue/base;
485           }while( longvalue>0 );
486         }
487         length = (int)(&zOut[nOut-1]-bufpt);
488         while( precision>length ){
489           *(--bufpt) = '0';                             /* Zero pad */
490           length++;
491         }
492         if( cThousand ){
493           int nn = (length - 1)/3;  /* Number of "," to insert */
494           int ix = (length - 1)%3 + 1;
495           bufpt -= nn;
496           for(idx=0; nn>0; idx++){
497             bufpt[idx] = bufpt[idx+nn];
498             ix--;
499             if( ix==0 ){
500               bufpt[++idx] = cThousand;
501               nn--;
502               ix = 3;
503             }
504           }
505         }
506         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
507         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
508           const char *pre;
509           char x;
510           pre = &aPrefix[infop->prefix];
511           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
512         }
513         length = (int)(&zOut[nOut-1]-bufpt);
514         break;
515       case etFLOAT:
516       case etEXP:
517       case etGENERIC:
518         if( bArgList ){
519           realvalue = getDoubleArg(pArgList);
520         }else{
521           realvalue = va_arg(ap,double);
522         }
523 #ifdef SQLITE_OMIT_FLOATING_POINT
524         length = 0;
525 #else
526         if( precision<0 ) precision = 6;         /* Set default precision */
527 #ifdef SQLITE_FP_PRECISION_LIMIT
528         if( precision>SQLITE_FP_PRECISION_LIMIT ){
529           precision = SQLITE_FP_PRECISION_LIMIT;
530         }
531 #endif
532         if( realvalue<0.0 ){
533           realvalue = -realvalue;
534           prefix = '-';
535         }else{
536           prefix = flag_prefix;
537         }
538         if( xtype==etGENERIC && precision>0 ) precision--;
539         testcase( precision>0xfff );
540         idx = precision & 0xfff;
541         rounder = arRound[idx%10];
542         while( idx>=10 ){ rounder *= 1.0e-10; idx -= 10; }
543         if( xtype==etFLOAT ){
544           double rx = (double)realvalue;
545           sqlite3_uint64 u;
546           int ex;
547           memcpy(&u, &rx, sizeof(u));
548           ex = -1023 + (int)((u>>52)&0x7ff);
549           if( precision+(ex/3) < 15 ) rounder += realvalue*3e-16;
550           realvalue += rounder;
551         }
552         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
553         exp = 0;
554         if( sqlite3IsNaN((double)realvalue) ){
555           bufpt = "NaN";
556           length = 3;
557           break;
558         }
559         if( realvalue>0.0 ){
560           LONGDOUBLE_TYPE scale = 1.0;
561           while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
562           while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }
563           while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
564           realvalue /= scale;
565           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
566           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
567           if( exp>350 ){
568             bufpt = buf;
569             buf[0] = prefix;
570             memcpy(buf+(prefix!=0),"Inf",4);
571             length = 3+(prefix!=0);
572             break;
573           }
574         }
575         bufpt = buf;
576         /*
577         ** If the field type is etGENERIC, then convert to either etEXP
578         ** or etFLOAT, as appropriate.
579         */
580         if( xtype!=etFLOAT ){
581           realvalue += rounder;
582           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
583         }
584         if( xtype==etGENERIC ){
585           flag_rtz = !flag_alternateform;
586           if( exp<-4 || exp>precision ){
587             xtype = etEXP;
588           }else{
589             precision = precision - exp;
590             xtype = etFLOAT;
591           }
592         }else{
593           flag_rtz = flag_altform2;
594         }
595         if( xtype==etEXP ){
596           e2 = 0;
597         }else{
598           e2 = exp;
599         }
600         {
601           i64 szBufNeeded;           /* Size of a temporary buffer needed */
602           szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;
603           if( szBufNeeded > etBUFSIZE ){
604             bufpt = zExtra = printfTempBuf(pAccum, szBufNeeded);
605             if( bufpt==0 ) return;
606           }
607         }
608         zOut = bufpt;
609         nsd = 16 + flag_altform2*10;
610         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
611         /* The sign in front of the number */
612         if( prefix ){
613           *(bufpt++) = prefix;
614         }
615         /* Digits prior to the decimal point */
616         if( e2<0 ){
617           *(bufpt++) = '0';
618         }else{
619           for(; e2>=0; e2--){
620             *(bufpt++) = et_getdigit(&realvalue,&nsd);
621           }
622         }
623         /* The decimal point */
624         if( flag_dp ){
625           *(bufpt++) = '.';
626         }
627         /* "0" digits after the decimal point but before the first
628         ** significant digit of the number */
629         for(e2++; e2<0; precision--, e2++){
630           assert( precision>0 );
631           *(bufpt++) = '0';
632         }
633         /* Significant digits after the decimal point */
634         while( (precision--)>0 ){
635           *(bufpt++) = et_getdigit(&realvalue,&nsd);
636         }
637         /* Remove trailing zeros and the "." if no digits follow the "." */
638         if( flag_rtz && flag_dp ){
639           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
640           assert( bufpt>zOut );
641           if( bufpt[-1]=='.' ){
642             if( flag_altform2 ){
643               *(bufpt++) = '0';
644             }else{
645               *(--bufpt) = 0;
646             }
647           }
648         }
649         /* Add the "eNNN" suffix */
650         if( xtype==etEXP ){
651           *(bufpt++) = aDigits[infop->charset];
652           if( exp<0 ){
653             *(bufpt++) = '-'; exp = -exp;
654           }else{
655             *(bufpt++) = '+';
656           }
657           if( exp>=100 ){
658             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */
659             exp %= 100;
660           }
661           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */
662           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */
663         }
664         *bufpt = 0;
665 
666         /* The converted number is in buf[] and zero terminated. Output it.
667         ** Note that the number is in the usual order, not reversed as with
668         ** integer conversions. */
669         length = (int)(bufpt-zOut);
670         bufpt = zOut;
671 
672         /* Special case:  Add leading zeros if the flag_zeropad flag is
673         ** set and we are not left justified */
674         if( flag_zeropad && !flag_leftjustify && length < width){
675           int i;
676           int nPad = width - length;
677           for(i=width; i>=nPad; i--){
678             bufpt[i] = bufpt[i-nPad];
679           }
680           i = prefix!=0;
681           while( nPad-- ) bufpt[i++] = '0';
682           length = width;
683         }
684 #endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */
685         break;
686       case etSIZE:
687         if( !bArgList ){
688           *(va_arg(ap,int*)) = pAccum->nChar;
689         }
690         length = width = 0;
691         break;
692       case etPERCENT:
693         buf[0] = '%';
694         bufpt = buf;
695         length = 1;
696         break;
697       case etCHARX:
698         if( bArgList ){
699           bufpt = getTextArg(pArgList);
700           length = 1;
701           if( bufpt ){
702             buf[0] = c = *(bufpt++);
703             if( (c&0xc0)==0xc0 ){
704               while( length<4 && (bufpt[0]&0xc0)==0x80 ){
705                 buf[length++] = *(bufpt++);
706               }
707             }
708           }else{
709             buf[0] = 0;
710           }
711         }else{
712           unsigned int ch = va_arg(ap,unsigned int);
713           if( ch<0x00080 ){
714             buf[0] = ch & 0xff;
715             length = 1;
716           }else if( ch<0x00800 ){
717             buf[0] = 0xc0 + (u8)((ch>>6)&0x1f);
718             buf[1] = 0x80 + (u8)(ch & 0x3f);
719             length = 2;
720           }else if( ch<0x10000 ){
721             buf[0] = 0xe0 + (u8)((ch>>12)&0x0f);
722             buf[1] = 0x80 + (u8)((ch>>6) & 0x3f);
723             buf[2] = 0x80 + (u8)(ch & 0x3f);
724             length = 3;
725           }else{
726             buf[0] = 0xf0 + (u8)((ch>>18) & 0x07);
727             buf[1] = 0x80 + (u8)((ch>>12) & 0x3f);
728             buf[2] = 0x80 + (u8)((ch>>6) & 0x3f);
729             buf[3] = 0x80 + (u8)(ch & 0x3f);
730             length = 4;
731           }
732         }
733         if( precision>1 ){
734           width -= precision-1;
735           if( width>1 && !flag_leftjustify ){
736             sqlite3_str_appendchar(pAccum, width-1, ' ');
737             width = 0;
738           }
739           while( precision-- > 1 ){
740             sqlite3_str_append(pAccum, buf, length);
741           }
742         }
743         bufpt = buf;
744         flag_altform2 = 1;
745         goto adjust_width_for_utf8;
746       case etSTRING:
747       case etDYNSTRING:
748         if( bArgList ){
749           bufpt = getTextArg(pArgList);
750           xtype = etSTRING;
751         }else{
752           bufpt = va_arg(ap,char*);
753         }
754         if( bufpt==0 ){
755           bufpt = "";
756         }else if( xtype==etDYNSTRING ){
757           if( pAccum->nChar==0
758            && pAccum->mxAlloc
759            && width==0
760            && precision<0
761            && pAccum->accError==0
762           ){
763             /* Special optimization for sqlite3_mprintf("%z..."):
764             ** Extend an existing memory allocation rather than creating
765             ** a new one. */
766             assert( (pAccum->printfFlags&SQLITE_PRINTF_MALLOCED)==0 );
767             pAccum->zText = bufpt;
768             pAccum->nAlloc = sqlite3DbMallocSize(pAccum->db, bufpt);
769             pAccum->nChar = 0x7fffffff & (int)strlen(bufpt);
770             pAccum->printfFlags |= SQLITE_PRINTF_MALLOCED;
771             length = 0;
772             break;
773           }
774           zExtra = bufpt;
775         }
776         if( precision>=0 ){
777           if( flag_altform2 ){
778             /* Set length to the number of bytes needed in order to display
779             ** precision characters */
780             unsigned char *z = (unsigned char*)bufpt;
781             while( precision-- > 0 && z[0] ){
782               SQLITE_SKIP_UTF8(z);
783             }
784             length = (int)(z - (unsigned char*)bufpt);
785           }else{
786             for(length=0; length<precision && bufpt[length]; length++){}
787           }
788         }else{
789           length = 0x7fffffff & (int)strlen(bufpt);
790         }
791       adjust_width_for_utf8:
792         if( flag_altform2 && width>0 ){
793           /* Adjust width to account for extra bytes in UTF-8 characters */
794           int ii = length - 1;
795           while( ii>=0 ) if( (bufpt[ii--] & 0xc0)==0x80 ) width++;
796         }
797         break;
798       case etSQLESCAPE:           /* %q: Escape ' characters */
799       case etSQLESCAPE2:          /* %Q: Escape ' and enclose in '...' */
800       case etSQLESCAPE3: {        /* %w: Escape " characters */
801         int i, j, k, n, isnull;
802         int needQuote;
803         char ch;
804         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
805         char *escarg;
806 
807         if( bArgList ){
808           escarg = getTextArg(pArgList);
809         }else{
810           escarg = va_arg(ap,char*);
811         }
812         isnull = escarg==0;
813         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
814         /* For %q, %Q, and %w, the precision is the number of bytes (or
815         ** characters if the ! flags is present) to use from the input.
816         ** Because of the extra quoting characters inserted, the number
817         ** of output characters may be larger than the precision.
818         */
819         k = precision;
820         for(i=n=0; k!=0 && (ch=escarg[i])!=0; i++, k--){
821           if( ch==q )  n++;
822           if( flag_altform2 && (ch&0xc0)==0xc0 ){
823             while( (escarg[i+1]&0xc0)==0x80 ){ i++; }
824           }
825         }
826         needQuote = !isnull && xtype==etSQLESCAPE2;
827         n += i + 3;
828         if( n>etBUFSIZE ){
829           bufpt = zExtra = printfTempBuf(pAccum, n);
830           if( bufpt==0 ) return;
831         }else{
832           bufpt = buf;
833         }
834         j = 0;
835         if( needQuote ) bufpt[j++] = q;
836         k = i;
837         for(i=0; i<k; i++){
838           bufpt[j++] = ch = escarg[i];
839           if( ch==q ) bufpt[j++] = ch;
840         }
841         if( needQuote ) bufpt[j++] = q;
842         bufpt[j] = 0;
843         length = j;
844         goto adjust_width_for_utf8;
845       }
846       case etTOKEN: {
847         Token *pToken;
848         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
849         pToken = va_arg(ap, Token*);
850         assert( bArgList==0 );
851         if( pToken && pToken->n ){
852           sqlite3_str_append(pAccum, (const char*)pToken->z, pToken->n);
853         }
854         length = width = 0;
855         break;
856       }
857       case etSRCLIST: {
858         SrcList *pSrc;
859         int k;
860         struct SrcList_item *pItem;
861         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
862         pSrc = va_arg(ap, SrcList*);
863         k = va_arg(ap, int);
864         pItem = &pSrc->a[k];
865         assert( bArgList==0 );
866         assert( k>=0 && k<pSrc->nSrc );
867         if( pItem->zDatabase ){
868           sqlite3_str_appendall(pAccum, pItem->zDatabase);
869           sqlite3_str_append(pAccum, ".", 1);
870         }
871         sqlite3_str_appendall(pAccum, pItem->zName);
872         length = width = 0;
873         break;
874       }
875       default: {
876         assert( xtype==etINVALID );
877         return;
878       }
879     }/* End switch over the format type */
880     /*
881     ** The text of the conversion is pointed to by "bufpt" and is
882     ** "length" characters long.  The field width is "width".  Do
883     ** the output.  Both length and width are in bytes, not characters,
884     ** at this point.  If the "!" flag was present on string conversions
885     ** indicating that width and precision should be expressed in characters,
886     ** then the values have been translated prior to reaching this point.
887     */
888     width -= length;
889     if( width>0 ){
890       if( !flag_leftjustify ) sqlite3_str_appendchar(pAccum, width, ' ');
891       sqlite3_str_append(pAccum, bufpt, length);
892       if( flag_leftjustify ) sqlite3_str_appendchar(pAccum, width, ' ');
893     }else{
894       sqlite3_str_append(pAccum, bufpt, length);
895     }
896 
897     if( zExtra ){
898       sqlite3DbFree(pAccum->db, zExtra);
899       zExtra = 0;
900     }
901   }/* End for loop over the format string */
902 } /* End of function */
903 
904 /*
905 ** Enlarge the memory allocation on a StrAccum object so that it is
906 ** able to accept at least N more bytes of text.
907 **
908 ** Return the number of bytes of text that StrAccum is able to accept
909 ** after the attempted enlargement.  The value returned might be zero.
910 */
911 static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
912   char *zNew;
913   assert( p->nChar+(i64)N >= p->nAlloc ); /* Only called if really needed */
914   if( p->accError ){
915     testcase(p->accError==SQLITE_TOOBIG);
916     testcase(p->accError==SQLITE_NOMEM);
917     return 0;
918   }
919   if( p->mxAlloc==0 ){
920     setStrAccumError(p, SQLITE_TOOBIG);
921     return p->nAlloc - p->nChar - 1;
922   }else{
923     char *zOld = isMalloced(p) ? p->zText : 0;
924     i64 szNew = p->nChar;
925     szNew += N + 1;
926     if( szNew+p->nChar<=p->mxAlloc ){
927       /* Force exponential buffer size growth as long as it does not overflow,
928       ** to avoid having to call this routine too often */
929       szNew += p->nChar;
930     }
931     if( szNew > p->mxAlloc ){
932       sqlite3_str_reset(p);
933       setStrAccumError(p, SQLITE_TOOBIG);
934       return 0;
935     }else{
936       p->nAlloc = (int)szNew;
937     }
938     if( p->db ){
939       zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
940     }else{
941       zNew = sqlite3Realloc(zOld, p->nAlloc);
942     }
943     if( zNew ){
944       assert( p->zText!=0 || p->nChar==0 );
945       if( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
946       p->zText = zNew;
947       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
948       p->printfFlags |= SQLITE_PRINTF_MALLOCED;
949     }else{
950       sqlite3_str_reset(p);
951       setStrAccumError(p, SQLITE_NOMEM);
952       return 0;
953     }
954   }
955   return N;
956 }
957 
958 /*
959 ** Append N copies of character c to the given string buffer.
960 */
961 void sqlite3_str_appendchar(sqlite3_str *p, int N, char c){
962   testcase( p->nChar + (i64)N > 0x7fffffff );
963   if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
964     return;
965   }
966   while( (N--)>0 ) p->zText[p->nChar++] = c;
967 }
968 
969 /*
970 ** The StrAccum "p" is not large enough to accept N new bytes of z[].
971 ** So enlarge if first, then do the append.
972 **
973 ** This is a helper routine to sqlite3_str_append() that does special-case
974 ** work (enlarging the buffer) using tail recursion, so that the
975 ** sqlite3_str_append() routine can use fast calling semantics.
976 */
977 static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
978   N = sqlite3StrAccumEnlarge(p, N);
979   if( N>0 ){
980     memcpy(&p->zText[p->nChar], z, N);
981     p->nChar += N;
982   }
983 }
984 
985 /*
986 ** Append N bytes of text from z to the StrAccum object.  Increase the
987 ** size of the memory allocation for StrAccum if necessary.
988 */
989 void sqlite3_str_append(sqlite3_str *p, const char *z, int N){
990   assert( z!=0 || N==0 );
991   assert( p->zText!=0 || p->nChar==0 || p->accError );
992   assert( N>=0 );
993   assert( p->accError==0 || p->nAlloc==0 || p->mxAlloc==0 );
994   if( p->nChar+N >= p->nAlloc ){
995     enlargeAndAppend(p,z,N);
996   }else if( N ){
997     assert( p->zText );
998     p->nChar += N;
999     memcpy(&p->zText[p->nChar-N], z, N);
1000   }
1001 }
1002 
1003 /*
1004 ** Append the complete text of zero-terminated string z[] to the p string.
1005 */
1006 void sqlite3_str_appendall(sqlite3_str *p, const char *z){
1007   sqlite3_str_append(p, z, sqlite3Strlen30(z));
1008 }
1009 
1010 
1011 /*
1012 ** Finish off a string by making sure it is zero-terminated.
1013 ** Return a pointer to the resulting string.  Return a NULL
1014 ** pointer if any kind of error was encountered.
1015 */
1016 static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){
1017   char *zText;
1018   assert( p->mxAlloc>0 && !isMalloced(p) );
1019   zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
1020   if( zText ){
1021     memcpy(zText, p->zText, p->nChar+1);
1022     p->printfFlags |= SQLITE_PRINTF_MALLOCED;
1023   }else{
1024     setStrAccumError(p, SQLITE_NOMEM);
1025   }
1026   p->zText = zText;
1027   return zText;
1028 }
1029 char *sqlite3StrAccumFinish(StrAccum *p){
1030   if( p->zText ){
1031     p->zText[p->nChar] = 0;
1032     if( p->mxAlloc>0 && !isMalloced(p) ){
1033       return strAccumFinishRealloc(p);
1034     }
1035   }
1036   return p->zText;
1037 }
1038 
1039 /*
1040 ** This singleton is an sqlite3_str object that is returned if
1041 ** sqlite3_malloc() fails to provide space for a real one.  This
1042 ** sqlite3_str object accepts no new text and always returns
1043 ** an SQLITE_NOMEM error.
1044 */
1045 static sqlite3_str sqlite3OomStr = {
1046    0, 0, 0, 0, 0, SQLITE_NOMEM, 0
1047 };
1048 
1049 /* Finalize a string created using sqlite3_str_new().
1050 */
1051 char *sqlite3_str_finish(sqlite3_str *p){
1052   char *z;
1053   if( p!=0 && p!=&sqlite3OomStr ){
1054     z = sqlite3StrAccumFinish(p);
1055     sqlite3_free(p);
1056   }else{
1057     z = 0;
1058   }
1059   return z;
1060 }
1061 
1062 /* Return any error code associated with p */
1063 int sqlite3_str_errcode(sqlite3_str *p){
1064   return p ? p->accError : SQLITE_NOMEM;
1065 }
1066 
1067 /* Return the current length of p in bytes */
1068 int sqlite3_str_length(sqlite3_str *p){
1069   return p ? p->nChar : 0;
1070 }
1071 
1072 /* Return the current value for p */
1073 char *sqlite3_str_value(sqlite3_str *p){
1074   if( p==0 || p->nChar==0 ) return 0;
1075   p->zText[p->nChar] = 0;
1076   return p->zText;
1077 }
1078 
1079 /*
1080 ** Reset an StrAccum string.  Reclaim all malloced memory.
1081 */
1082 void sqlite3_str_reset(StrAccum *p){
1083   if( isMalloced(p) ){
1084     sqlite3DbFree(p->db, p->zText);
1085     p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;
1086   }
1087   p->nAlloc = 0;
1088   p->nChar = 0;
1089   p->zText = 0;
1090 }
1091 
1092 /*
1093 ** Initialize a string accumulator.
1094 **
1095 ** p:     The accumulator to be initialized.
1096 ** db:    Pointer to a database connection.  May be NULL.  Lookaside
1097 **        memory is used if not NULL. db->mallocFailed is set appropriately
1098 **        when not NULL.
1099 ** zBase: An initial buffer.  May be NULL in which case the initial buffer
1100 **        is malloced.
1101 ** n:     Size of zBase in bytes.  If total space requirements never exceed
1102 **        n then no memory allocations ever occur.
1103 ** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
1104 **        allocations will ever occur.
1105 */
1106 void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
1107   p->zText = zBase;
1108   p->db = db;
1109   p->nAlloc = n;
1110   p->mxAlloc = mx;
1111   p->nChar = 0;
1112   p->accError = 0;
1113   p->printfFlags = 0;
1114 }
1115 
1116 /* Allocate and initialize a new dynamic string object */
1117 sqlite3_str *sqlite3_str_new(sqlite3 *db){
1118   sqlite3_str *p = sqlite3_malloc64(sizeof(*p));
1119   if( p ){
1120     sqlite3StrAccumInit(p, 0, 0, 0,
1121             db ? db->aLimit[SQLITE_LIMIT_LENGTH] : SQLITE_MAX_LENGTH);
1122   }else{
1123     p = &sqlite3OomStr;
1124   }
1125   return p;
1126 }
1127 
1128 /*
1129 ** Print into memory obtained from sqliteMalloc().  Use the internal
1130 ** %-conversion extensions.
1131 */
1132 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
1133   char *z;
1134   char zBase[SQLITE_PRINT_BUF_SIZE];
1135   StrAccum acc;
1136   assert( db!=0 );
1137   sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
1138                       db->aLimit[SQLITE_LIMIT_LENGTH]);
1139   acc.printfFlags = SQLITE_PRINTF_INTERNAL;
1140   sqlite3_str_vappendf(&acc, zFormat, ap);
1141   z = sqlite3StrAccumFinish(&acc);
1142   if( acc.accError==SQLITE_NOMEM ){
1143     sqlite3OomFault(db);
1144   }
1145   return z;
1146 }
1147 
1148 /*
1149 ** Print into memory obtained from sqliteMalloc().  Use the internal
1150 ** %-conversion extensions.
1151 */
1152 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
1153   va_list ap;
1154   char *z;
1155   va_start(ap, zFormat);
1156   z = sqlite3VMPrintf(db, zFormat, ap);
1157   va_end(ap);
1158   return z;
1159 }
1160 
1161 /*
1162 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
1163 ** %-conversion extensions.
1164 */
1165 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
1166   char *z;
1167   char zBase[SQLITE_PRINT_BUF_SIZE];
1168   StrAccum acc;
1169 
1170 #ifdef SQLITE_ENABLE_API_ARMOR
1171   if( zFormat==0 ){
1172     (void)SQLITE_MISUSE_BKPT;
1173     return 0;
1174   }
1175 #endif
1176 #ifndef SQLITE_OMIT_AUTOINIT
1177   if( sqlite3_initialize() ) return 0;
1178 #endif
1179   sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
1180   sqlite3_str_vappendf(&acc, zFormat, ap);
1181   z = sqlite3StrAccumFinish(&acc);
1182   return z;
1183 }
1184 
1185 /*
1186 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
1187 ** %-conversion extensions.
1188 */
1189 char *sqlite3_mprintf(const char *zFormat, ...){
1190   va_list ap;
1191   char *z;
1192 #ifndef SQLITE_OMIT_AUTOINIT
1193   if( sqlite3_initialize() ) return 0;
1194 #endif
1195   va_start(ap, zFormat);
1196   z = sqlite3_vmprintf(zFormat, ap);
1197   va_end(ap);
1198   return z;
1199 }
1200 
1201 /*
1202 ** sqlite3_snprintf() works like snprintf() except that it ignores the
1203 ** current locale settings.  This is important for SQLite because we
1204 ** are not able to use a "," as the decimal point in place of "." as
1205 ** specified by some locales.
1206 **
1207 ** Oops:  The first two arguments of sqlite3_snprintf() are backwards
1208 ** from the snprintf() standard.  Unfortunately, it is too late to change
1209 ** this without breaking compatibility, so we just have to live with the
1210 ** mistake.
1211 **
1212 ** sqlite3_vsnprintf() is the varargs version.
1213 */
1214 char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
1215   StrAccum acc;
1216   if( n<=0 ) return zBuf;
1217 #ifdef SQLITE_ENABLE_API_ARMOR
1218   if( zBuf==0 || zFormat==0 ) {
1219     (void)SQLITE_MISUSE_BKPT;
1220     if( zBuf ) zBuf[0] = 0;
1221     return zBuf;
1222   }
1223 #endif
1224   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
1225   sqlite3_str_vappendf(&acc, zFormat, ap);
1226   zBuf[acc.nChar] = 0;
1227   return zBuf;
1228 }
1229 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
1230   char *z;
1231   va_list ap;
1232   va_start(ap,zFormat);
1233   z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);
1234   va_end(ap);
1235   return z;
1236 }
1237 
1238 /*
1239 ** This is the routine that actually formats the sqlite3_log() message.
1240 ** We house it in a separate routine from sqlite3_log() to avoid using
1241 ** stack space on small-stack systems when logging is disabled.
1242 **
1243 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
1244 ** allocate memory because it might be called while the memory allocator
1245 ** mutex is held.
1246 **
1247 ** sqlite3_str_vappendf() might ask for *temporary* memory allocations for
1248 ** certain format characters (%q) or for very large precisions or widths.
1249 ** Care must be taken that any sqlite3_log() calls that occur while the
1250 ** memory mutex is held do not use these mechanisms.
1251 */
1252 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
1253   StrAccum acc;                          /* String accumulator */
1254   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
1255 
1256   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
1257   sqlite3_str_vappendf(&acc, zFormat, ap);
1258   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
1259                            sqlite3StrAccumFinish(&acc));
1260 }
1261 
1262 /*
1263 ** Format and write a message to the log if logging is enabled.
1264 */
1265 void sqlite3_log(int iErrCode, const char *zFormat, ...){
1266   va_list ap;                             /* Vararg list */
1267   if( sqlite3GlobalConfig.xLog ){
1268     va_start(ap, zFormat);
1269     renderLogMsg(iErrCode, zFormat, ap);
1270     va_end(ap);
1271   }
1272 }
1273 
1274 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
1275 /*
1276 ** A version of printf() that understands %lld.  Used for debugging.
1277 ** The printf() built into some versions of windows does not understand %lld
1278 ** and segfaults if you give it a long long int.
1279 */
1280 void sqlite3DebugPrintf(const char *zFormat, ...){
1281   va_list ap;
1282   StrAccum acc;
1283   char zBuf[SQLITE_PRINT_BUF_SIZE*10];
1284   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
1285   va_start(ap,zFormat);
1286   sqlite3_str_vappendf(&acc, zFormat, ap);
1287   va_end(ap);
1288   sqlite3StrAccumFinish(&acc);
1289 #ifdef SQLITE_OS_TRACE_PROC
1290   {
1291     extern void SQLITE_OS_TRACE_PROC(const char *zBuf, int nBuf);
1292     SQLITE_OS_TRACE_PROC(zBuf, sizeof(zBuf));
1293   }
1294 #else
1295   fprintf(stdout,"%s", zBuf);
1296   fflush(stdout);
1297 #endif
1298 }
1299 #endif
1300 
1301 
1302 /*
1303 ** variable-argument wrapper around sqlite3_str_vappendf(). The bFlags argument
1304 ** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
1305 */
1306 void sqlite3_str_appendf(StrAccum *p, const char *zFormat, ...){
1307   va_list ap;
1308   va_start(ap,zFormat);
1309   sqlite3_str_vappendf(p, zFormat, ap);
1310   va_end(ap);
1311 }
1312