xref: /sqlite-3.40.0/src/printf.c (revision 8ccdef6b)
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       1 /* Integer types.  %d, %x, %o, and so forth */
19 #define etFLOAT       2 /* Floating point.  %f */
20 #define etEXP         3 /* Exponentional notation. %e and %E */
21 #define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
22 #define etSIZE        5 /* Return number of characters processed so far. %n */
23 #define etSTRING      6 /* Strings. %s */
24 #define etDYNSTRING   7 /* Dynamically allocated strings. %z */
25 #define etPERCENT     8 /* Percent symbol. %% */
26 #define etCHARX       9 /* Characters. %c */
27 /* The rest are extensions, not normally found in printf() */
28 #define etSQLESCAPE  10 /* Strings with '\'' doubled.  %q */
29 #define etSQLESCAPE2 11 /* Strings with '\'' doubled and enclosed in '',
30                           NULL pointers replaced by SQL NULL.  %Q */
31 #define etTOKEN      12 /* a pointer to a Token structure */
32 #define etSRCLIST    13 /* a pointer to a SrcList */
33 #define etPOINTER    14 /* The %p conversion */
34 #define etSQLESCAPE3 15 /* %w -> Strings with '\"' doubled */
35 #define etORDINAL    16 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
36 
37 #define etINVALID     0 /* Any unrecognized conversion type */
38 
39 
40 /*
41 ** An "etByte" is an 8-bit unsigned value.
42 */
43 typedef unsigned char etByte;
44 
45 /*
46 ** Each builtin conversion character (ex: the 'd' in "%d") is described
47 ** by an instance of the following structure
48 */
49 typedef struct et_info {   /* Information about each format field */
50   char fmttype;            /* The format field code letter */
51   etByte base;             /* The base for radix conversion */
52   etByte flags;            /* One or more of FLAG_ constants below */
53   etByte type;             /* Conversion paradigm */
54   etByte charset;          /* Offset into aDigits[] of the digits string */
55   etByte prefix;           /* Offset into aPrefix[] of the prefix string */
56 } et_info;
57 
58 /*
59 ** Allowed values for et_info.flags
60 */
61 #define FLAG_SIGNED  1     /* True if the value to convert is signed */
62 #define FLAG_INTERN  2     /* True if for internal use only */
63 #define FLAG_STRING  4     /* Allow infinity 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, etRADIX,      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, etRADIX,      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, etRADIX,      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 have the FLAG_INTERN bit set and are thus for internal
97 ** use only */
98   {  'T',  0, 2, etTOKEN,      0,  0 },
99   {  'S',  0, 2, etSRCLIST,    0,  0 },
100   {  'r', 10, 3, etORDINAL,    0,  0 },
101 };
102 
103 /*
104 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
105 ** conversions will work.
106 */
107 #ifndef SQLITE_OMIT_FLOATING_POINT
108 /*
109 ** "*val" is a double such that 0.1 <= *val < 10.0
110 ** Return the ascii code for the leading digit of *val, then
111 ** multiply "*val" by 10.0 to renormalize.
112 **
113 ** Example:
114 **     input:     *val = 3.14159
115 **     output:    *val = 1.4159    function return = '3'
116 **
117 ** The counter *cnt is incremented each time.  After counter exceeds
118 ** 16 (the number of significant digits in a 64-bit float) '0' is
119 ** always returned.
120 */
121 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
122   int digit;
123   LONGDOUBLE_TYPE d;
124   if( (*cnt)<=0 ) return '0';
125   (*cnt)--;
126   digit = (int)*val;
127   d = digit;
128   digit += '0';
129   *val = (*val - d)*10.0;
130   return (char)digit;
131 }
132 #endif /* SQLITE_OMIT_FLOATING_POINT */
133 
134 /*
135 ** Set the StrAccum object to an error mode.
136 */
137 static void setStrAccumError(StrAccum *p, u8 eError){
138   assert( eError==STRACCUM_NOMEM || eError==STRACCUM_TOOBIG );
139   p->accError = eError;
140   p->nAlloc = 0;
141 }
142 
143 /*
144 ** Extra argument values from a PrintfArguments object
145 */
146 static sqlite3_int64 getIntArg(PrintfArguments *p){
147   if( p->nArg<=p->nUsed ) return 0;
148   return sqlite3_value_int64(p->apArg[p->nUsed++]);
149 }
150 static double getDoubleArg(PrintfArguments *p){
151   if( p->nArg<=p->nUsed ) return 0.0;
152   return sqlite3_value_double(p->apArg[p->nUsed++]);
153 }
154 static char *getTextArg(PrintfArguments *p){
155   if( p->nArg<=p->nUsed ) return 0;
156   return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
157 }
158 
159 
160 /*
161 ** On machines with a small stack size, you can redefine the
162 ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
163 */
164 #ifndef SQLITE_PRINT_BUF_SIZE
165 # define SQLITE_PRINT_BUF_SIZE 70
166 #endif
167 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
168 
169 /*
170 ** Render a string given by "fmt" into the StrAccum object.
171 */
172 void sqlite3VXPrintf(
173   StrAccum *pAccum,          /* Accumulate results here */
174   u32 bFlags,                /* SQLITE_PRINTF_* flags */
175   const char *fmt,           /* Format string */
176   va_list ap                 /* arguments */
177 ){
178   int c;                     /* Next character in the format string */
179   char *bufpt;               /* Pointer to the conversion buffer */
180   int precision;             /* Precision of the current field */
181   int length;                /* Length of the field */
182   int idx;                   /* A general purpose loop counter */
183   int width;                 /* Width of the current field */
184   etByte flag_leftjustify;   /* True if "-" flag is present */
185   etByte flag_plussign;      /* True if "+" flag is present */
186   etByte flag_blanksign;     /* True if " " flag is present */
187   etByte flag_alternateform; /* True if "#" flag is present */
188   etByte flag_altform2;      /* True if "!" flag is present */
189   etByte flag_zeropad;       /* True if field width constant starts with zero */
190   etByte flag_long;          /* True if "l" flag is present */
191   etByte flag_longlong;      /* True if the "ll" flag is present */
192   etByte done;               /* Loop termination flag */
193   etByte xtype = 0;          /* Conversion paradigm */
194   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
195   u8 useIntern;              /* Ok to use internal conversions (ex: %T) */
196   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
197   sqlite_uint64 longvalue;   /* Value for integer types */
198   LONGDOUBLE_TYPE realvalue; /* Value for real types */
199   const et_info *infop;      /* Pointer to the appropriate info structure */
200   char *zOut;                /* Rendering buffer */
201   int nOut;                  /* Size of the rendering buffer */
202   char *zExtra = 0;          /* Malloced memory used by some conversion */
203 #ifndef SQLITE_OMIT_FLOATING_POINT
204   int  exp, e2;              /* exponent of real numbers */
205   int nsd;                   /* Number of significant digits returned */
206   double rounder;            /* Used for rounding floating point values */
207   etByte flag_dp;            /* True if decimal point should be shown */
208   etByte flag_rtz;           /* True if trailing zeros should be removed */
209 #endif
210   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
211   char buf[etBUFSIZE];       /* Conversion buffer */
212 
213   bufpt = 0;
214   if( bFlags ){
215     if( (bArgList = (bFlags & SQLITE_PRINTF_SQLFUNC))!=0 ){
216       pArgList = va_arg(ap, PrintfArguments*);
217     }
218     useIntern = bFlags & SQLITE_PRINTF_INTERNAL;
219   }else{
220     bArgList = useIntern = 0;
221   }
222   for(; (c=(*fmt))!=0; ++fmt){
223     if( c!='%' ){
224       bufpt = (char *)fmt;
225 #if HAVE_STRCHRNUL
226       fmt = strchrnul(fmt, '%');
227 #else
228       do{ fmt++; }while( *fmt && *fmt != '%' );
229 #endif
230       sqlite3StrAccumAppend(pAccum, bufpt, (int)(fmt - bufpt));
231       if( *fmt==0 ) break;
232     }
233     if( (c=(*++fmt))==0 ){
234       sqlite3StrAccumAppend(pAccum, "%", 1);
235       break;
236     }
237     /* Find out what flags are present */
238     flag_leftjustify = flag_plussign = flag_blanksign =
239      flag_alternateform = flag_altform2 = flag_zeropad = 0;
240     done = 0;
241     do{
242       switch( c ){
243         case '-':   flag_leftjustify = 1;     break;
244         case '+':   flag_plussign = 1;        break;
245         case ' ':   flag_blanksign = 1;       break;
246         case '#':   flag_alternateform = 1;   break;
247         case '!':   flag_altform2 = 1;        break;
248         case '0':   flag_zeropad = 1;         break;
249         default:    done = 1;                 break;
250       }
251     }while( !done && (c=(*++fmt))!=0 );
252     /* Get the field width */
253     if( c=='*' ){
254       if( bArgList ){
255         width = (int)getIntArg(pArgList);
256       }else{
257         width = va_arg(ap,int);
258       }
259       if( width<0 ){
260         flag_leftjustify = 1;
261         width = width >= -2147483647 ? -width : 0;
262       }
263       c = *++fmt;
264     }else{
265       unsigned wx = 0;
266       while( c>='0' && c<='9' ){
267         wx = wx*10 + c - '0';
268         c = *++fmt;
269       }
270       testcase( wx>0x7fffffff );
271       width = wx & 0x7fffffff;
272     }
273     assert( width>=0 );
274 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
275     if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
276       width = SQLITE_PRINTF_PRECISION_LIMIT;
277     }
278 #endif
279 
280     /* Get the precision */
281     if( c=='.' ){
282       c = *++fmt;
283       if( c=='*' ){
284         if( bArgList ){
285           precision = (int)getIntArg(pArgList);
286         }else{
287           precision = va_arg(ap,int);
288         }
289         c = *++fmt;
290         if( precision<0 ){
291           precision = precision >= -2147483647 ? -precision : -1;
292         }
293       }else{
294         unsigned px = 0;
295         while( c>='0' && c<='9' ){
296           px = px*10 + c - '0';
297           c = *++fmt;
298         }
299         testcase( px>0x7fffffff );
300         precision = px & 0x7fffffff;
301       }
302     }else{
303       precision = -1;
304     }
305     assert( precision>=(-1) );
306 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
307     if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
308       precision = SQLITE_PRINTF_PRECISION_LIMIT;
309     }
310 #endif
311 
312 
313     /* Get the conversion type modifier */
314     if( c=='l' ){
315       flag_long = 1;
316       c = *++fmt;
317       if( c=='l' ){
318         flag_longlong = 1;
319         c = *++fmt;
320       }else{
321         flag_longlong = 0;
322       }
323     }else{
324       flag_long = flag_longlong = 0;
325     }
326     /* Fetch the info entry for the field */
327     infop = &fmtinfo[0];
328     xtype = etINVALID;
329     for(idx=0; idx<ArraySize(fmtinfo); idx++){
330       if( c==fmtinfo[idx].fmttype ){
331         infop = &fmtinfo[idx];
332         if( useIntern || (infop->flags & FLAG_INTERN)==0 ){
333           xtype = infop->type;
334         }else{
335           return;
336         }
337         break;
338       }
339     }
340 
341     /*
342     ** At this point, variables are initialized as follows:
343     **
344     **   flag_alternateform          TRUE if a '#' is present.
345     **   flag_altform2               TRUE if a '!' is present.
346     **   flag_plussign               TRUE if a '+' is present.
347     **   flag_leftjustify            TRUE if a '-' is present or if the
348     **                               field width was negative.
349     **   flag_zeropad                TRUE if the width began with 0.
350     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
351     **                               the conversion character.
352     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
353     **                               the conversion character.
354     **   flag_blanksign              TRUE if a ' ' is present.
355     **   width                       The specified field width.  This is
356     **                               always non-negative.  Zero is the default.
357     **   precision                   The specified precision.  The default
358     **                               is -1.
359     **   xtype                       The class of the conversion.
360     **   infop                       Pointer to the appropriate info struct.
361     */
362     switch( xtype ){
363       case etPOINTER:
364         flag_longlong = sizeof(char*)==sizeof(i64);
365         flag_long = sizeof(char*)==sizeof(long int);
366         /* Fall through into the next case */
367       case etORDINAL:
368       case etRADIX:
369         if( infop->flags & FLAG_SIGNED ){
370           i64 v;
371           if( bArgList ){
372             v = getIntArg(pArgList);
373           }else if( flag_longlong ){
374             v = va_arg(ap,i64);
375           }else if( flag_long ){
376             v = va_arg(ap,long int);
377           }else{
378             v = va_arg(ap,int);
379           }
380           if( v<0 ){
381             if( v==SMALLEST_INT64 ){
382               longvalue = ((u64)1)<<63;
383             }else{
384               longvalue = -v;
385             }
386             prefix = '-';
387           }else{
388             longvalue = v;
389             if( flag_plussign )        prefix = '+';
390             else if( flag_blanksign )  prefix = ' ';
391             else                       prefix = 0;
392           }
393         }else{
394           if( bArgList ){
395             longvalue = (u64)getIntArg(pArgList);
396           }else if( flag_longlong ){
397             longvalue = va_arg(ap,u64);
398           }else if( flag_long ){
399             longvalue = va_arg(ap,unsigned long int);
400           }else{
401             longvalue = va_arg(ap,unsigned int);
402           }
403           prefix = 0;
404         }
405         if( longvalue==0 ) flag_alternateform = 0;
406         if( flag_zeropad && precision<width-(prefix!=0) ){
407           precision = width-(prefix!=0);
408         }
409         if( precision<etBUFSIZE-10 ){
410           nOut = etBUFSIZE;
411           zOut = buf;
412         }else{
413           nOut = precision + 10;
414           zOut = zExtra = sqlite3Malloc( nOut );
415           if( zOut==0 ){
416             setStrAccumError(pAccum, STRACCUM_NOMEM);
417             return;
418           }
419         }
420         bufpt = &zOut[nOut-1];
421         if( xtype==etORDINAL ){
422           static const char zOrd[] = "thstndrd";
423           int x = (int)(longvalue % 10);
424           if( x>=4 || (longvalue/10)%10==1 ){
425             x = 0;
426           }
427           *(--bufpt) = zOrd[x*2+1];
428           *(--bufpt) = zOrd[x*2];
429         }
430         {
431           const char *cset = &aDigits[infop->charset];
432           u8 base = infop->base;
433           do{                                           /* Convert to ascii */
434             *(--bufpt) = cset[longvalue%base];
435             longvalue = longvalue/base;
436           }while( longvalue>0 );
437         }
438         length = (int)(&zOut[nOut-1]-bufpt);
439         for(idx=precision-length; idx>0; idx--){
440           *(--bufpt) = '0';                             /* Zero pad */
441         }
442         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
443         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
444           const char *pre;
445           char x;
446           pre = &aPrefix[infop->prefix];
447           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
448         }
449         length = (int)(&zOut[nOut-1]-bufpt);
450         break;
451       case etFLOAT:
452       case etEXP:
453       case etGENERIC:
454         if( bArgList ){
455           realvalue = getDoubleArg(pArgList);
456         }else{
457           realvalue = va_arg(ap,double);
458         }
459 #ifdef SQLITE_OMIT_FLOATING_POINT
460         length = 0;
461 #else
462         if( precision<0 ) precision = 6;         /* Set default precision */
463         if( realvalue<0.0 ){
464           realvalue = -realvalue;
465           prefix = '-';
466         }else{
467           if( flag_plussign )          prefix = '+';
468           else if( flag_blanksign )    prefix = ' ';
469           else                         prefix = 0;
470         }
471         if( xtype==etGENERIC && precision>0 ) precision--;
472         testcase( precision>0xfff );
473         for(idx=precision&0xfff, rounder=0.5; idx>0; idx--, rounder*=0.1){}
474         if( xtype==etFLOAT ) realvalue += rounder;
475         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
476         exp = 0;
477         if( sqlite3IsNaN((double)realvalue) ){
478           bufpt = "NaN";
479           length = 3;
480           break;
481         }
482         if( realvalue>0.0 ){
483           LONGDOUBLE_TYPE scale = 1.0;
484           while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
485           while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }
486           while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
487           realvalue /= scale;
488           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
489           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
490           if( exp>350 ){
491             bufpt = buf;
492             buf[0] = prefix;
493             memcpy(buf+(prefix!=0),"Inf",4);
494             length = 3+(prefix!=0);
495             break;
496           }
497         }
498         bufpt = buf;
499         /*
500         ** If the field type is etGENERIC, then convert to either etEXP
501         ** or etFLOAT, as appropriate.
502         */
503         if( xtype!=etFLOAT ){
504           realvalue += rounder;
505           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
506         }
507         if( xtype==etGENERIC ){
508           flag_rtz = !flag_alternateform;
509           if( exp<-4 || exp>precision ){
510             xtype = etEXP;
511           }else{
512             precision = precision - exp;
513             xtype = etFLOAT;
514           }
515         }else{
516           flag_rtz = flag_altform2;
517         }
518         if( xtype==etEXP ){
519           e2 = 0;
520         }else{
521           e2 = exp;
522         }
523         if( MAX(e2,0)+(i64)precision+(i64)width > etBUFSIZE - 15 ){
524           bufpt = zExtra
525               = sqlite3Malloc( MAX(e2,0)+(i64)precision+(i64)width+15 );
526           if( bufpt==0 ){
527             setStrAccumError(pAccum, STRACCUM_NOMEM);
528             return;
529           }
530         }
531         zOut = bufpt;
532         nsd = 16 + flag_altform2*10;
533         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
534         /* The sign in front of the number */
535         if( prefix ){
536           *(bufpt++) = prefix;
537         }
538         /* Digits prior to the decimal point */
539         if( e2<0 ){
540           *(bufpt++) = '0';
541         }else{
542           for(; e2>=0; e2--){
543             *(bufpt++) = et_getdigit(&realvalue,&nsd);
544           }
545         }
546         /* The decimal point */
547         if( flag_dp ){
548           *(bufpt++) = '.';
549         }
550         /* "0" digits after the decimal point but before the first
551         ** significant digit of the number */
552         for(e2++; e2<0; precision--, e2++){
553           assert( precision>0 );
554           *(bufpt++) = '0';
555         }
556         /* Significant digits after the decimal point */
557         while( (precision--)>0 ){
558           *(bufpt++) = et_getdigit(&realvalue,&nsd);
559         }
560         /* Remove trailing zeros and the "." if no digits follow the "." */
561         if( flag_rtz && flag_dp ){
562           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
563           assert( bufpt>zOut );
564           if( bufpt[-1]=='.' ){
565             if( flag_altform2 ){
566               *(bufpt++) = '0';
567             }else{
568               *(--bufpt) = 0;
569             }
570           }
571         }
572         /* Add the "eNNN" suffix */
573         if( xtype==etEXP ){
574           *(bufpt++) = aDigits[infop->charset];
575           if( exp<0 ){
576             *(bufpt++) = '-'; exp = -exp;
577           }else{
578             *(bufpt++) = '+';
579           }
580           if( exp>=100 ){
581             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */
582             exp %= 100;
583           }
584           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */
585           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */
586         }
587         *bufpt = 0;
588 
589         /* The converted number is in buf[] and zero terminated. Output it.
590         ** Note that the number is in the usual order, not reversed as with
591         ** integer conversions. */
592         length = (int)(bufpt-zOut);
593         bufpt = zOut;
594 
595         /* Special case:  Add leading zeros if the flag_zeropad flag is
596         ** set and we are not left justified */
597         if( flag_zeropad && !flag_leftjustify && length < width){
598           int i;
599           int nPad = width - length;
600           for(i=width; i>=nPad; i--){
601             bufpt[i] = bufpt[i-nPad];
602           }
603           i = prefix!=0;
604           while( nPad-- ) bufpt[i++] = '0';
605           length = width;
606         }
607 #endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */
608         break;
609       case etSIZE:
610         if( !bArgList ){
611           *(va_arg(ap,int*)) = pAccum->nChar;
612         }
613         length = width = 0;
614         break;
615       case etPERCENT:
616         buf[0] = '%';
617         bufpt = buf;
618         length = 1;
619         break;
620       case etCHARX:
621         if( bArgList ){
622           bufpt = getTextArg(pArgList);
623           c = bufpt ? bufpt[0] : 0;
624         }else{
625           c = va_arg(ap,int);
626         }
627         if( precision>1 ){
628           width -= precision-1;
629           if( width>1 && !flag_leftjustify ){
630             sqlite3AppendChar(pAccum, width-1, ' ');
631             width = 0;
632           }
633           sqlite3AppendChar(pAccum, precision-1, c);
634         }
635         length = 1;
636         buf[0] = c;
637         bufpt = buf;
638         break;
639       case etSTRING:
640       case etDYNSTRING:
641         if( bArgList ){
642           bufpt = getTextArg(pArgList);
643           xtype = etSTRING;
644         }else{
645           bufpt = va_arg(ap,char*);
646         }
647         if( bufpt==0 ){
648           bufpt = "";
649         }else if( xtype==etDYNSTRING ){
650           zExtra = bufpt;
651         }
652         if( precision>=0 ){
653           for(length=0; length<precision && bufpt[length]; length++){}
654         }else{
655           length = sqlite3Strlen30(bufpt);
656         }
657         break;
658       case etSQLESCAPE:           /* Escape ' characters */
659       case etSQLESCAPE2:          /* Escape ' and enclose in '...' */
660       case etSQLESCAPE3: {        /* Escape " characters */
661         int i, j, k, n, isnull;
662         int needQuote;
663         char ch;
664         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
665         char *escarg;
666 
667         if( bArgList ){
668           escarg = getTextArg(pArgList);
669         }else{
670           escarg = va_arg(ap,char*);
671         }
672         isnull = escarg==0;
673         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
674         k = precision;
675         for(i=n=0; k!=0 && (ch=escarg[i])!=0; i++, k--){
676           if( ch==q )  n++;
677         }
678         needQuote = !isnull && xtype==etSQLESCAPE2;
679         n += i + 3;
680         if( n>etBUFSIZE ){
681           bufpt = zExtra = sqlite3Malloc( n );
682           if( bufpt==0 ){
683             setStrAccumError(pAccum, STRACCUM_NOMEM);
684             return;
685           }
686         }else{
687           bufpt = buf;
688         }
689         j = 0;
690         if( needQuote ) bufpt[j++] = q;
691         k = i;
692         for(i=0; i<k; i++){
693           bufpt[j++] = ch = escarg[i];
694           if( ch==q ) bufpt[j++] = ch;
695         }
696         if( needQuote ) bufpt[j++] = q;
697         bufpt[j] = 0;
698         length = j;
699         /* The precision in %q and %Q means how many input characters to
700         ** consume, not the length of the output...
701         ** if( precision>=0 && precision<length ) length = precision; */
702         break;
703       }
704       case etTOKEN: {
705         Token *pToken = va_arg(ap, Token*);
706         assert( bArgList==0 );
707         if( pToken && pToken->n ){
708           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
709         }
710         length = width = 0;
711         break;
712       }
713       case etSRCLIST: {
714         SrcList *pSrc = va_arg(ap, SrcList*);
715         int k = va_arg(ap, int);
716         struct SrcList_item *pItem = &pSrc->a[k];
717         assert( bArgList==0 );
718         assert( k>=0 && k<pSrc->nSrc );
719         if( pItem->zDatabase ){
720           sqlite3StrAccumAppendAll(pAccum, pItem->zDatabase);
721           sqlite3StrAccumAppend(pAccum, ".", 1);
722         }
723         sqlite3StrAccumAppendAll(pAccum, pItem->zName);
724         length = width = 0;
725         break;
726       }
727       default: {
728         assert( xtype==etINVALID );
729         return;
730       }
731     }/* End switch over the format type */
732     /*
733     ** The text of the conversion is pointed to by "bufpt" and is
734     ** "length" characters long.  The field width is "width".  Do
735     ** the output.
736     */
737     width -= length;
738     if( width>0 && !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
739     sqlite3StrAccumAppend(pAccum, bufpt, length);
740     if( width>0 && flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
741 
742     if( zExtra ){
743       sqlite3DbFree(pAccum->db, zExtra);
744       zExtra = 0;
745     }
746   }/* End for loop over the format string */
747 } /* End of function */
748 
749 /*
750 ** Enlarge the memory allocation on a StrAccum object so that it is
751 ** able to accept at least N more bytes of text.
752 **
753 ** Return the number of bytes of text that StrAccum is able to accept
754 ** after the attempted enlargement.  The value returned might be zero.
755 */
756 static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
757   char *zNew;
758   assert( p->nChar+(i64)N >= p->nAlloc ); /* Only called if really needed */
759   if( p->accError ){
760     testcase(p->accError==STRACCUM_TOOBIG);
761     testcase(p->accError==STRACCUM_NOMEM);
762     return 0;
763   }
764   if( p->mxAlloc==0 ){
765     N = p->nAlloc - p->nChar - 1;
766     setStrAccumError(p, STRACCUM_TOOBIG);
767     return N;
768   }else{
769     char *zOld = p->bMalloced ? p->zText : 0;
770     i64 szNew = p->nChar;
771     assert( (p->zText==0 || p->zText==p->zBase)==(p->bMalloced==0) );
772     szNew += N + 1;
773     if( szNew+p->nChar<=p->mxAlloc ){
774       /* Force exponential buffer size growth as long as it does not overflow,
775       ** to avoid having to call this routine too often */
776       szNew += p->nChar;
777     }
778     if( szNew > p->mxAlloc ){
779       sqlite3StrAccumReset(p);
780       setStrAccumError(p, STRACCUM_TOOBIG);
781       return 0;
782     }else{
783       p->nAlloc = (int)szNew;
784     }
785     if( p->db ){
786       zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
787     }else{
788       zNew = sqlite3_realloc64(zOld, p->nAlloc);
789     }
790     if( zNew ){
791       assert( p->zText!=0 || p->nChar==0 );
792       if( !p->bMalloced && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
793       p->zText = zNew;
794       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
795       p->bMalloced = 1;
796     }else{
797       sqlite3StrAccumReset(p);
798       setStrAccumError(p, STRACCUM_NOMEM);
799       return 0;
800     }
801   }
802   return N;
803 }
804 
805 /*
806 ** Append N copies of character c to the given string buffer.
807 */
808 void sqlite3AppendChar(StrAccum *p, int N, char c){
809   testcase( p->nChar + (i64)N > 0x7fffffff );
810   if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
811     return;
812   }
813   assert( (p->zText==p->zBase)==(p->bMalloced==0) );
814   while( (N--)>0 ) p->zText[p->nChar++] = c;
815 }
816 
817 /*
818 ** The StrAccum "p" is not large enough to accept N new bytes of z[].
819 ** So enlarge if first, then do the append.
820 **
821 ** This is a helper routine to sqlite3StrAccumAppend() that does special-case
822 ** work (enlarging the buffer) using tail recursion, so that the
823 ** sqlite3StrAccumAppend() routine can use fast calling semantics.
824 */
825 static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
826   N = sqlite3StrAccumEnlarge(p, N);
827   if( N>0 ){
828     memcpy(&p->zText[p->nChar], z, N);
829     p->nChar += N;
830   }
831   assert( (p->zText==0 || p->zText==p->zBase)==(p->bMalloced==0) );
832 }
833 
834 /*
835 ** Append N bytes of text from z to the StrAccum object.  Increase the
836 ** size of the memory allocation for StrAccum if necessary.
837 */
838 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
839   assert( z!=0 || N==0 );
840   assert( p->zText!=0 || p->nChar==0 || p->accError );
841   assert( N>=0 );
842   assert( p->accError==0 || p->nAlloc==0 );
843   if( p->nChar+N >= p->nAlloc ){
844     enlargeAndAppend(p,z,N);
845   }else{
846     assert( p->zText );
847     p->nChar += N;
848     memcpy(&p->zText[p->nChar-N], z, N);
849   }
850 }
851 
852 /*
853 ** Append the complete text of zero-terminated string z[] to the p string.
854 */
855 void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
856   sqlite3StrAccumAppend(p, z, sqlite3Strlen30(z));
857 }
858 
859 
860 /*
861 ** Finish off a string by making sure it is zero-terminated.
862 ** Return a pointer to the resulting string.  Return a NULL
863 ** pointer if any kind of error was encountered.
864 */
865 char *sqlite3StrAccumFinish(StrAccum *p){
866   if( p->zText ){
867     assert( (p->zText==p->zBase)==(p->bMalloced==0) );
868     p->zText[p->nChar] = 0;
869     if( p->mxAlloc>0 && p->bMalloced==0 ){
870       p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
871       if( p->zText ){
872         memcpy(p->zText, p->zBase, p->nChar+1);
873         p->bMalloced = 1;
874       }else{
875         setStrAccumError(p, STRACCUM_NOMEM);
876       }
877     }
878   }
879   return p->zText;
880 }
881 
882 /*
883 ** Reset an StrAccum string.  Reclaim all malloced memory.
884 */
885 void sqlite3StrAccumReset(StrAccum *p){
886   assert( (p->zText==0 || p->zText==p->zBase)==(p->bMalloced==0) );
887   if( p->bMalloced ){
888     sqlite3DbFree(p->db, p->zText);
889     p->bMalloced = 0;
890   }
891   p->zText = 0;
892 }
893 
894 /*
895 ** Initialize a string accumulator.
896 **
897 ** p:     The accumulator to be initialized.
898 ** db:    Pointer to a database connection.  May be NULL.  Lookaside
899 **        memory is used if not NULL. db->mallocFailed is set appropriately
900 **        when not NULL.
901 ** zBase: An initial buffer.  May be NULL in which case the initial buffer
902 **        is malloced.
903 ** n:     Size of zBase in bytes.  If total space requirements never exceed
904 **        n then no memory allocations ever occur.
905 ** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
906 **        allocations will ever occur.
907 */
908 void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
909   p->zText = p->zBase = zBase;
910   p->db = db;
911   p->nChar = 0;
912   p->nAlloc = n;
913   p->mxAlloc = mx;
914   p->accError = 0;
915   p->bMalloced = 0;
916 }
917 
918 /*
919 ** Print into memory obtained from sqliteMalloc().  Use the internal
920 ** %-conversion extensions.
921 */
922 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
923   char *z;
924   char zBase[SQLITE_PRINT_BUF_SIZE];
925   StrAccum acc;
926   assert( db!=0 );
927   sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
928                       db->aLimit[SQLITE_LIMIT_LENGTH]);
929   sqlite3VXPrintf(&acc, SQLITE_PRINTF_INTERNAL, zFormat, ap);
930   z = sqlite3StrAccumFinish(&acc);
931   if( acc.accError==STRACCUM_NOMEM ){
932     db->mallocFailed = 1;
933   }
934   return z;
935 }
936 
937 /*
938 ** Print into memory obtained from sqliteMalloc().  Use the internal
939 ** %-conversion extensions.
940 */
941 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
942   va_list ap;
943   char *z;
944   va_start(ap, zFormat);
945   z = sqlite3VMPrintf(db, zFormat, ap);
946   va_end(ap);
947   return z;
948 }
949 
950 /*
951 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
952 ** %-conversion extensions.
953 */
954 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
955   char *z;
956   char zBase[SQLITE_PRINT_BUF_SIZE];
957   StrAccum acc;
958 
959 #ifdef SQLITE_ENABLE_API_ARMOR
960   if( zFormat==0 ){
961     (void)SQLITE_MISUSE_BKPT;
962     return 0;
963   }
964 #endif
965 #ifndef SQLITE_OMIT_AUTOINIT
966   if( sqlite3_initialize() ) return 0;
967 #endif
968   sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
969   sqlite3VXPrintf(&acc, 0, zFormat, ap);
970   z = sqlite3StrAccumFinish(&acc);
971   return z;
972 }
973 
974 /*
975 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
976 ** %-conversion extensions.
977 */
978 char *sqlite3_mprintf(const char *zFormat, ...){
979   va_list ap;
980   char *z;
981 #ifndef SQLITE_OMIT_AUTOINIT
982   if( sqlite3_initialize() ) return 0;
983 #endif
984   va_start(ap, zFormat);
985   z = sqlite3_vmprintf(zFormat, ap);
986   va_end(ap);
987   return z;
988 }
989 
990 /*
991 ** sqlite3_snprintf() works like snprintf() except that it ignores the
992 ** current locale settings.  This is important for SQLite because we
993 ** are not able to use a "," as the decimal point in place of "." as
994 ** specified by some locales.
995 **
996 ** Oops:  The first two arguments of sqlite3_snprintf() are backwards
997 ** from the snprintf() standard.  Unfortunately, it is too late to change
998 ** this without breaking compatibility, so we just have to live with the
999 ** mistake.
1000 **
1001 ** sqlite3_vsnprintf() is the varargs version.
1002 */
1003 char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
1004   StrAccum acc;
1005   if( n<=0 ) return zBuf;
1006 #ifdef SQLITE_ENABLE_API_ARMOR
1007   if( zBuf==0 || zFormat==0 ) {
1008     (void)SQLITE_MISUSE_BKPT;
1009     if( zBuf ) zBuf[0] = 0;
1010     return zBuf;
1011   }
1012 #endif
1013   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
1014   sqlite3VXPrintf(&acc, 0, zFormat, ap);
1015   return sqlite3StrAccumFinish(&acc);
1016 }
1017 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
1018   char *z;
1019   va_list ap;
1020   va_start(ap,zFormat);
1021   z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);
1022   va_end(ap);
1023   return z;
1024 }
1025 
1026 /*
1027 ** This is the routine that actually formats the sqlite3_log() message.
1028 ** We house it in a separate routine from sqlite3_log() to avoid using
1029 ** stack space on small-stack systems when logging is disabled.
1030 **
1031 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
1032 ** allocate memory because it might be called while the memory allocator
1033 ** mutex is held.
1034 **
1035 ** sqlite3VXPrintf() might ask for *temporary* memory allocations for
1036 ** certain format characters (%q) or for very large precisions or widths.
1037 ** Care must be taken that any sqlite3_log() calls that occur while the
1038 ** memory mutex is held do not use these mechanisms.
1039 */
1040 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
1041   StrAccum acc;                          /* String accumulator */
1042   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
1043 
1044   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
1045   sqlite3VXPrintf(&acc, 0, zFormat, ap);
1046   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
1047                            sqlite3StrAccumFinish(&acc));
1048 }
1049 
1050 /*
1051 ** Format and write a message to the log if logging is enabled.
1052 */
1053 void sqlite3_log(int iErrCode, const char *zFormat, ...){
1054   va_list ap;                             /* Vararg list */
1055   if( sqlite3GlobalConfig.xLog ){
1056     va_start(ap, zFormat);
1057     renderLogMsg(iErrCode, zFormat, ap);
1058     va_end(ap);
1059   }
1060 }
1061 
1062 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
1063 /*
1064 ** A version of printf() that understands %lld.  Used for debugging.
1065 ** The printf() built into some versions of windows does not understand %lld
1066 ** and segfaults if you give it a long long int.
1067 */
1068 void sqlite3DebugPrintf(const char *zFormat, ...){
1069   va_list ap;
1070   StrAccum acc;
1071   char zBuf[500];
1072   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
1073   va_start(ap,zFormat);
1074   sqlite3VXPrintf(&acc, 0, zFormat, ap);
1075   va_end(ap);
1076   sqlite3StrAccumFinish(&acc);
1077   fprintf(stdout,"%s", zBuf);
1078   fflush(stdout);
1079 }
1080 #endif
1081 
1082 
1083 /*
1084 ** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
1085 ** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
1086 */
1087 void sqlite3XPrintf(StrAccum *p, u32 bFlags, const char *zFormat, ...){
1088   va_list ap;
1089   va_start(ap,zFormat);
1090   sqlite3VXPrintf(p, bFlags, zFormat, ap);
1091   va_end(ap);
1092 }
1093