xref: /sqlite-3.40.0/src/printf.c (revision 666d34c7)
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 /* Integer types.  %d, %x, %o, and so forth */
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 
37 #define etINVALID    16 /* 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_STRING  4     /* Allow infinity precision */
63 
64 
65 /*
66 ** The following table is searched linearly, so it is good to put the
67 ** most frequently used conversion types first.
68 */
69 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
70 static const char aPrefix[] = "-x0\000X0";
71 static const et_info fmtinfo[] = {
72   {  'd', 10, 1, etRADIX,      0,  0 },
73   {  's',  0, 4, etSTRING,     0,  0 },
74   {  'g',  0, 1, etGENERIC,    30, 0 },
75   {  'z',  0, 4, etDYNSTRING,  0,  0 },
76   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
77   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
78   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
79   {  'c',  0, 0, etCHARX,      0,  0 },
80   {  'o',  8, 0, etRADIX,      0,  2 },
81   {  'u', 10, 0, etRADIX,      0,  0 },
82   {  'x', 16, 0, etRADIX,      16, 1 },
83   {  'X', 16, 0, etRADIX,      0,  4 },
84 #ifndef SQLITE_OMIT_FLOATING_POINT
85   {  'f',  0, 1, etFLOAT,      0,  0 },
86   {  'e',  0, 1, etEXP,        30, 0 },
87   {  'E',  0, 1, etEXP,        14, 0 },
88   {  'G',  0, 1, etGENERIC,    14, 0 },
89 #endif
90   {  'i', 10, 1, etRADIX,      0,  0 },
91   {  'n',  0, 0, etSIZE,       0,  0 },
92   {  '%',  0, 0, etPERCENT,    0,  0 },
93   {  'p', 16, 0, etPOINTER,    0,  1 },
94 
95   /* All the rest are undocumented and are for internal use only */
96   {  'T',  0, 0, etTOKEN,      0,  0 },
97   {  'S',  0, 0, etSRCLIST,    0,  0 },
98   {  'r', 10, 1, etORDINAL,    0,  0 },
99 };
100 
101 /*
102 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
103 ** conversions will work.
104 */
105 #ifndef SQLITE_OMIT_FLOATING_POINT
106 /*
107 ** "*val" is a double such that 0.1 <= *val < 10.0
108 ** Return the ascii code for the leading digit of *val, then
109 ** multiply "*val" by 10.0 to renormalize.
110 **
111 ** Example:
112 **     input:     *val = 3.14159
113 **     output:    *val = 1.4159    function return = '3'
114 **
115 ** The counter *cnt is incremented each time.  After counter exceeds
116 ** 16 (the number of significant digits in a 64-bit float) '0' is
117 ** always returned.
118 */
119 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
120   int digit;
121   LONGDOUBLE_TYPE d;
122   if( (*cnt)<=0 ) return '0';
123   (*cnt)--;
124   digit = (int)*val;
125   d = digit;
126   digit += '0';
127   *val = (*val - d)*10.0;
128   return (char)digit;
129 }
130 #endif /* SQLITE_OMIT_FLOATING_POINT */
131 
132 /*
133 ** Set the StrAccum object to an error mode.
134 */
135 static void setStrAccumError(StrAccum *p, u8 eError){
136   assert( eError==STRACCUM_NOMEM || eError==STRACCUM_TOOBIG );
137   p->accError = eError;
138   p->nAlloc = 0;
139 }
140 
141 /*
142 ** Extra argument values from a PrintfArguments object
143 */
144 static sqlite3_int64 getIntArg(PrintfArguments *p){
145   if( p->nArg<=p->nUsed ) return 0;
146   return sqlite3_value_int64(p->apArg[p->nUsed++]);
147 }
148 static double getDoubleArg(PrintfArguments *p){
149   if( p->nArg<=p->nUsed ) return 0.0;
150   return sqlite3_value_double(p->apArg[p->nUsed++]);
151 }
152 static char *getTextArg(PrintfArguments *p){
153   if( p->nArg<=p->nUsed ) return 0;
154   return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
155 }
156 
157 
158 /*
159 ** On machines with a small stack size, you can redefine the
160 ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
161 */
162 #ifndef SQLITE_PRINT_BUF_SIZE
163 # define SQLITE_PRINT_BUF_SIZE 70
164 #endif
165 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
166 
167 /*
168 ** Render a string given by "fmt" into the StrAccum object.
169 */
170 void sqlite3VXPrintf(
171   StrAccum *pAccum,          /* Accumulate results here */
172   const char *fmt,           /* Format string */
173   va_list ap                 /* arguments */
174 ){
175   int c;                     /* Next character in the format string */
176   char *bufpt;               /* Pointer to the conversion buffer */
177   int precision;             /* Precision of the current field */
178   int length;                /* Length of the field */
179   int idx;                   /* A general purpose loop counter */
180   int width;                 /* Width of the current field */
181   etByte flag_leftjustify;   /* True if "-" flag is present */
182   etByte flag_plussign;      /* True if "+" flag is present */
183   etByte flag_blanksign;     /* True if " " flag is present */
184   etByte flag_alternateform; /* True if "#" flag is present */
185   etByte flag_altform2;      /* True if "!" flag is present */
186   etByte flag_zeropad;       /* True if field width constant starts with zero */
187   etByte flag_long;          /* True if "l" flag is present */
188   etByte flag_longlong;      /* True if the "ll" flag is present */
189   etByte done;               /* Loop termination flag */
190   etByte xtype = etINVALID;  /* Conversion paradigm */
191   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
192   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
193   sqlite_uint64 longvalue;   /* Value for integer types */
194   LONGDOUBLE_TYPE realvalue; /* Value for real types */
195   const et_info *infop;      /* Pointer to the appropriate info structure */
196   char *zOut;                /* Rendering buffer */
197   int nOut;                  /* Size of the rendering buffer */
198   char *zExtra = 0;          /* Malloced memory used by some conversion */
199 #ifndef SQLITE_OMIT_FLOATING_POINT
200   int  exp, e2;              /* exponent of real numbers */
201   int nsd;                   /* Number of significant digits returned */
202   double rounder;            /* Used for rounding floating point values */
203   etByte flag_dp;            /* True if decimal point should be shown */
204   etByte flag_rtz;           /* True if trailing zeros should be removed */
205 #endif
206   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
207   char buf[etBUFSIZE];       /* Conversion buffer */
208 
209   bufpt = 0;
210   if( (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC)!=0 ){
211     pArgList = va_arg(ap, PrintfArguments*);
212     bArgList = 1;
213   }else{
214     bArgList = 0;
215   }
216   for(; (c=(*fmt))!=0; ++fmt){
217     if( c!='%' ){
218       bufpt = (char *)fmt;
219 #if HAVE_STRCHRNUL
220       fmt = strchrnul(fmt, '%');
221 #else
222       do{ fmt++; }while( *fmt && *fmt != '%' );
223 #endif
224       sqlite3StrAccumAppend(pAccum, bufpt, (int)(fmt - bufpt));
225       if( *fmt==0 ) break;
226     }
227     if( (c=(*++fmt))==0 ){
228       sqlite3StrAccumAppend(pAccum, "%", 1);
229       break;
230     }
231     /* Find out what flags are present */
232     flag_leftjustify = flag_plussign = flag_blanksign =
233      flag_alternateform = flag_altform2 = flag_zeropad = 0;
234     done = 0;
235     do{
236       switch( c ){
237         case '-':   flag_leftjustify = 1;     break;
238         case '+':   flag_plussign = 1;        break;
239         case ' ':   flag_blanksign = 1;       break;
240         case '#':   flag_alternateform = 1;   break;
241         case '!':   flag_altform2 = 1;        break;
242         case '0':   flag_zeropad = 1;         break;
243         default:    done = 1;                 break;
244       }
245     }while( !done && (c=(*++fmt))!=0 );
246     /* Get the field width */
247     if( c=='*' ){
248       if( bArgList ){
249         width = (int)getIntArg(pArgList);
250       }else{
251         width = va_arg(ap,int);
252       }
253       if( width<0 ){
254         flag_leftjustify = 1;
255         width = width >= -2147483647 ? -width : 0;
256       }
257       c = *++fmt;
258     }else{
259       unsigned wx = 0;
260       while( c>='0' && c<='9' ){
261         wx = wx*10 + c - '0';
262         c = *++fmt;
263       }
264       testcase( wx>0x7fffffff );
265       width = wx & 0x7fffffff;
266     }
267     assert( width>=0 );
268 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
269     if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
270       width = SQLITE_PRINTF_PRECISION_LIMIT;
271     }
272 #endif
273 
274     /* Get the precision */
275     if( c=='.' ){
276       c = *++fmt;
277       if( c=='*' ){
278         if( bArgList ){
279           precision = (int)getIntArg(pArgList);
280         }else{
281           precision = va_arg(ap,int);
282         }
283         c = *++fmt;
284         if( precision<0 ){
285           precision = precision >= -2147483647 ? -precision : -1;
286         }
287       }else{
288         unsigned px = 0;
289         while( c>='0' && c<='9' ){
290           px = px*10 + c - '0';
291           c = *++fmt;
292         }
293         testcase( px>0x7fffffff );
294         precision = px & 0x7fffffff;
295       }
296     }else{
297       precision = -1;
298     }
299     assert( precision>=(-1) );
300 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
301     if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
302       precision = SQLITE_PRINTF_PRECISION_LIMIT;
303     }
304 #endif
305 
306 
307     /* Get the conversion type modifier */
308     if( c=='l' ){
309       flag_long = 1;
310       c = *++fmt;
311       if( c=='l' ){
312         flag_longlong = 1;
313         c = *++fmt;
314       }else{
315         flag_longlong = 0;
316       }
317     }else{
318       flag_long = flag_longlong = 0;
319     }
320     /* Fetch the info entry for the field */
321     infop = &fmtinfo[0];
322     xtype = etINVALID;
323     for(idx=0; idx<ArraySize(fmtinfo); idx++){
324       if( c==fmtinfo[idx].fmttype ){
325         infop = &fmtinfo[idx];
326         xtype = infop->type;
327         break;
328       }
329     }
330 
331     /*
332     ** At this point, variables are initialized as follows:
333     **
334     **   flag_alternateform          TRUE if a '#' is present.
335     **   flag_altform2               TRUE if a '!' is present.
336     **   flag_plussign               TRUE if a '+' is present.
337     **   flag_leftjustify            TRUE if a '-' is present or if the
338     **                               field width was negative.
339     **   flag_zeropad                TRUE if the width began with 0.
340     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
341     **                               the conversion character.
342     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
343     **                               the conversion character.
344     **   flag_blanksign              TRUE if a ' ' is present.
345     **   width                       The specified field width.  This is
346     **                               always non-negative.  Zero is the default.
347     **   precision                   The specified precision.  The default
348     **                               is -1.
349     **   xtype                       The class of the conversion.
350     **   infop                       Pointer to the appropriate info struct.
351     */
352     switch( xtype ){
353       case etPOINTER:
354         flag_longlong = sizeof(char*)==sizeof(i64);
355         flag_long = sizeof(char*)==sizeof(long int);
356         /* Fall through into the next case */
357       case etORDINAL:
358       case etRADIX:
359         if( infop->flags & FLAG_SIGNED ){
360           i64 v;
361           if( bArgList ){
362             v = getIntArg(pArgList);
363           }else if( flag_longlong ){
364             v = va_arg(ap,i64);
365           }else if( flag_long ){
366             v = va_arg(ap,long int);
367           }else{
368             v = va_arg(ap,int);
369           }
370           if( v<0 ){
371             if( v==SMALLEST_INT64 ){
372               longvalue = ((u64)1)<<63;
373             }else{
374               longvalue = -v;
375             }
376             prefix = '-';
377           }else{
378             longvalue = v;
379             if( flag_plussign )        prefix = '+';
380             else if( flag_blanksign )  prefix = ' ';
381             else                       prefix = 0;
382           }
383         }else{
384           if( bArgList ){
385             longvalue = (u64)getIntArg(pArgList);
386           }else if( flag_longlong ){
387             longvalue = va_arg(ap,u64);
388           }else if( flag_long ){
389             longvalue = va_arg(ap,unsigned long int);
390           }else{
391             longvalue = va_arg(ap,unsigned int);
392           }
393           prefix = 0;
394         }
395         if( longvalue==0 ) flag_alternateform = 0;
396         if( flag_zeropad && precision<width-(prefix!=0) ){
397           precision = width-(prefix!=0);
398         }
399         if( precision<etBUFSIZE-10 ){
400           nOut = etBUFSIZE;
401           zOut = buf;
402         }else{
403           nOut = precision + 10;
404           zOut = zExtra = sqlite3Malloc( nOut );
405           if( zOut==0 ){
406             setStrAccumError(pAccum, STRACCUM_NOMEM);
407             return;
408           }
409         }
410         bufpt = &zOut[nOut-1];
411         if( xtype==etORDINAL ){
412           static const char zOrd[] = "thstndrd";
413           int x = (int)(longvalue % 10);
414           if( x>=4 || (longvalue/10)%10==1 ){
415             x = 0;
416           }
417           *(--bufpt) = zOrd[x*2+1];
418           *(--bufpt) = zOrd[x*2];
419         }
420         {
421           const char *cset = &aDigits[infop->charset];
422           u8 base = infop->base;
423           do{                                           /* Convert to ascii */
424             *(--bufpt) = cset[longvalue%base];
425             longvalue = longvalue/base;
426           }while( longvalue>0 );
427         }
428         length = (int)(&zOut[nOut-1]-bufpt);
429         for(idx=precision-length; idx>0; idx--){
430           *(--bufpt) = '0';                             /* Zero pad */
431         }
432         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
433         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
434           const char *pre;
435           char x;
436           pre = &aPrefix[infop->prefix];
437           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
438         }
439         length = (int)(&zOut[nOut-1]-bufpt);
440         break;
441       case etFLOAT:
442       case etEXP:
443       case etGENERIC:
444         if( bArgList ){
445           realvalue = getDoubleArg(pArgList);
446         }else{
447           realvalue = va_arg(ap,double);
448         }
449 #ifdef SQLITE_OMIT_FLOATING_POINT
450         length = 0;
451 #else
452         if( precision<0 ) precision = 6;         /* Set default precision */
453         if( realvalue<0.0 ){
454           realvalue = -realvalue;
455           prefix = '-';
456         }else{
457           if( flag_plussign )          prefix = '+';
458           else if( flag_blanksign )    prefix = ' ';
459           else                         prefix = 0;
460         }
461         if( xtype==etGENERIC && precision>0 ) precision--;
462         testcase( precision>0xfff );
463         for(idx=precision&0xfff, rounder=0.5; idx>0; idx--, rounder*=0.1){}
464         if( xtype==etFLOAT ) realvalue += rounder;
465         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
466         exp = 0;
467         if( sqlite3IsNaN((double)realvalue) ){
468           bufpt = "NaN";
469           length = 3;
470           break;
471         }
472         if( realvalue>0.0 ){
473           LONGDOUBLE_TYPE scale = 1.0;
474           while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
475           while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }
476           while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
477           realvalue /= scale;
478           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
479           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
480           if( exp>350 ){
481             bufpt = buf;
482             buf[0] = prefix;
483             memcpy(buf+(prefix!=0),"Inf",4);
484             length = 3+(prefix!=0);
485             break;
486           }
487         }
488         bufpt = buf;
489         /*
490         ** If the field type is etGENERIC, then convert to either etEXP
491         ** or etFLOAT, as appropriate.
492         */
493         if( xtype!=etFLOAT ){
494           realvalue += rounder;
495           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
496         }
497         if( xtype==etGENERIC ){
498           flag_rtz = !flag_alternateform;
499           if( exp<-4 || exp>precision ){
500             xtype = etEXP;
501           }else{
502             precision = precision - exp;
503             xtype = etFLOAT;
504           }
505         }else{
506           flag_rtz = flag_altform2;
507         }
508         if( xtype==etEXP ){
509           e2 = 0;
510         }else{
511           e2 = exp;
512         }
513         if( MAX(e2,0)+(i64)precision+(i64)width > etBUFSIZE - 15 ){
514           bufpt = zExtra
515               = sqlite3Malloc( MAX(e2,0)+(i64)precision+(i64)width+15 );
516           if( bufpt==0 ){
517             setStrAccumError(pAccum, STRACCUM_NOMEM);
518             return;
519           }
520         }
521         zOut = bufpt;
522         nsd = 16 + flag_altform2*10;
523         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
524         /* The sign in front of the number */
525         if( prefix ){
526           *(bufpt++) = prefix;
527         }
528         /* Digits prior to the decimal point */
529         if( e2<0 ){
530           *(bufpt++) = '0';
531         }else{
532           for(; e2>=0; e2--){
533             *(bufpt++) = et_getdigit(&realvalue,&nsd);
534           }
535         }
536         /* The decimal point */
537         if( flag_dp ){
538           *(bufpt++) = '.';
539         }
540         /* "0" digits after the decimal point but before the first
541         ** significant digit of the number */
542         for(e2++; e2<0; precision--, e2++){
543           assert( precision>0 );
544           *(bufpt++) = '0';
545         }
546         /* Significant digits after the decimal point */
547         while( (precision--)>0 ){
548           *(bufpt++) = et_getdigit(&realvalue,&nsd);
549         }
550         /* Remove trailing zeros and the "." if no digits follow the "." */
551         if( flag_rtz && flag_dp ){
552           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
553           assert( bufpt>zOut );
554           if( bufpt[-1]=='.' ){
555             if( flag_altform2 ){
556               *(bufpt++) = '0';
557             }else{
558               *(--bufpt) = 0;
559             }
560           }
561         }
562         /* Add the "eNNN" suffix */
563         if( xtype==etEXP ){
564           *(bufpt++) = aDigits[infop->charset];
565           if( exp<0 ){
566             *(bufpt++) = '-'; exp = -exp;
567           }else{
568             *(bufpt++) = '+';
569           }
570           if( exp>=100 ){
571             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */
572             exp %= 100;
573           }
574           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */
575           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */
576         }
577         *bufpt = 0;
578 
579         /* The converted number is in buf[] and zero terminated. Output it.
580         ** Note that the number is in the usual order, not reversed as with
581         ** integer conversions. */
582         length = (int)(bufpt-zOut);
583         bufpt = zOut;
584 
585         /* Special case:  Add leading zeros if the flag_zeropad flag is
586         ** set and we are not left justified */
587         if( flag_zeropad && !flag_leftjustify && length < width){
588           int i;
589           int nPad = width - length;
590           for(i=width; i>=nPad; i--){
591             bufpt[i] = bufpt[i-nPad];
592           }
593           i = prefix!=0;
594           while( nPad-- ) bufpt[i++] = '0';
595           length = width;
596         }
597 #endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */
598         break;
599       case etSIZE:
600         if( !bArgList ){
601           *(va_arg(ap,int*)) = pAccum->nChar;
602         }
603         length = width = 0;
604         break;
605       case etPERCENT:
606         buf[0] = '%';
607         bufpt = buf;
608         length = 1;
609         break;
610       case etCHARX:
611         if( bArgList ){
612           bufpt = getTextArg(pArgList);
613           c = bufpt ? bufpt[0] : 0;
614         }else{
615           c = va_arg(ap,int);
616         }
617         if( precision>1 ){
618           width -= precision-1;
619           if( width>1 && !flag_leftjustify ){
620             sqlite3AppendChar(pAccum, width-1, ' ');
621             width = 0;
622           }
623           sqlite3AppendChar(pAccum, precision-1, c);
624         }
625         length = 1;
626         buf[0] = c;
627         bufpt = buf;
628         break;
629       case etSTRING:
630       case etDYNSTRING:
631         if( bArgList ){
632           bufpt = getTextArg(pArgList);
633           xtype = etSTRING;
634         }else{
635           bufpt = va_arg(ap,char*);
636         }
637         if( bufpt==0 ){
638           bufpt = "";
639         }else if( xtype==etDYNSTRING ){
640           zExtra = bufpt;
641         }
642         if( precision>=0 ){
643           for(length=0; length<precision && bufpt[length]; length++){}
644         }else{
645           length = sqlite3Strlen30(bufpt);
646         }
647         break;
648       case etSQLESCAPE:           /* Escape ' characters */
649       case etSQLESCAPE2:          /* Escape ' and enclose in '...' */
650       case etSQLESCAPE3: {        /* Escape " characters */
651         int i, j, k, n, isnull;
652         int needQuote;
653         char ch;
654         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
655         char *escarg;
656 
657         if( bArgList ){
658           escarg = getTextArg(pArgList);
659         }else{
660           escarg = va_arg(ap,char*);
661         }
662         isnull = escarg==0;
663         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
664         k = precision;
665         for(i=n=0; k!=0 && (ch=escarg[i])!=0; i++, k--){
666           if( ch==q )  n++;
667         }
668         needQuote = !isnull && xtype==etSQLESCAPE2;
669         n += i + 3;
670         if( n>etBUFSIZE ){
671           bufpt = zExtra = sqlite3Malloc( n );
672           if( bufpt==0 ){
673             setStrAccumError(pAccum, STRACCUM_NOMEM);
674             return;
675           }
676         }else{
677           bufpt = buf;
678         }
679         j = 0;
680         if( needQuote ) bufpt[j++] = q;
681         k = i;
682         for(i=0; i<k; i++){
683           bufpt[j++] = ch = escarg[i];
684           if( ch==q ) bufpt[j++] = ch;
685         }
686         if( needQuote ) bufpt[j++] = q;
687         bufpt[j] = 0;
688         length = j;
689         /* The precision in %q and %Q means how many input characters to
690         ** consume, not the length of the output...
691         ** if( precision>=0 && precision<length ) length = precision; */
692         break;
693       }
694       case etTOKEN: {
695         Token *pToken;
696         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
697         pToken = va_arg(ap, Token*);
698         assert( bArgList==0 );
699         if( pToken && pToken->n ){
700           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
701         }
702         length = width = 0;
703         break;
704       }
705       case etSRCLIST: {
706         SrcList *pSrc;
707         int k;
708         struct SrcList_item *pItem;
709         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
710         pSrc = va_arg(ap, SrcList*);
711         k = va_arg(ap, int);
712         pItem = &pSrc->a[k];
713         assert( bArgList==0 );
714         assert( k>=0 && k<pSrc->nSrc );
715         if( pItem->zDatabase ){
716           sqlite3StrAccumAppendAll(pAccum, pItem->zDatabase);
717           sqlite3StrAccumAppend(pAccum, ".", 1);
718         }
719         sqlite3StrAccumAppendAll(pAccum, pItem->zName);
720         length = width = 0;
721         break;
722       }
723       default: {
724         assert( xtype==etINVALID );
725         return;
726       }
727     }/* End switch over the format type */
728     /*
729     ** The text of the conversion is pointed to by "bufpt" and is
730     ** "length" characters long.  The field width is "width".  Do
731     ** the output.
732     */
733     width -= length;
734     if( width>0 ){
735       if( !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
736       sqlite3StrAccumAppend(pAccum, bufpt, length);
737       if( flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
738     }else{
739       sqlite3StrAccumAppend(pAccum, bufpt, length);
740     }
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 = isMalloced(p) ? p->zText : 0;
770     i64 szNew = p->nChar;
771     assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
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( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
793       p->zText = zNew;
794       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
795       p->printfFlags |= SQLITE_PRINTF_MALLOCED;
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)==!isMalloced(p) );
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)==!isMalloced(p) );
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 if( N ){
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 static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){
866   assert( p->mxAlloc>0 && !isMalloced(p) );
867   p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
868   if( p->zText ){
869     memcpy(p->zText, p->zBase, p->nChar+1);
870     p->printfFlags |= SQLITE_PRINTF_MALLOCED;
871   }else{
872     setStrAccumError(p, STRACCUM_NOMEM);
873   }
874   return p->zText;
875 }
876 char *sqlite3StrAccumFinish(StrAccum *p){
877   if( p->zText ){
878     assert( (p->zText==p->zBase)==!isMalloced(p) );
879     p->zText[p->nChar] = 0;
880     if( p->mxAlloc>0 && !isMalloced(p) ){
881       return strAccumFinishRealloc(p);
882     }
883   }
884   return p->zText;
885 }
886 
887 /*
888 ** Reset an StrAccum string.  Reclaim all malloced memory.
889 */
890 void sqlite3StrAccumReset(StrAccum *p){
891   assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
892   if( isMalloced(p) ){
893     sqlite3DbFree(p->db, p->zText);
894     p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;
895   }
896   p->zText = 0;
897 }
898 
899 /*
900 ** Initialize a string accumulator.
901 **
902 ** p:     The accumulator to be initialized.
903 ** db:    Pointer to a database connection.  May be NULL.  Lookaside
904 **        memory is used if not NULL. db->mallocFailed is set appropriately
905 **        when not NULL.
906 ** zBase: An initial buffer.  May be NULL in which case the initial buffer
907 **        is malloced.
908 ** n:     Size of zBase in bytes.  If total space requirements never exceed
909 **        n then no memory allocations ever occur.
910 ** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
911 **        allocations will ever occur.
912 */
913 void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
914   p->zText = p->zBase = zBase;
915   p->db = db;
916   p->nChar = 0;
917   p->nAlloc = n;
918   p->mxAlloc = mx;
919   p->accError = 0;
920   p->printfFlags = 0;
921 }
922 
923 /*
924 ** Print into memory obtained from sqliteMalloc().  Use the internal
925 ** %-conversion extensions.
926 */
927 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
928   char *z;
929   char zBase[SQLITE_PRINT_BUF_SIZE];
930   StrAccum acc;
931   assert( db!=0 );
932   sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
933                       db->aLimit[SQLITE_LIMIT_LENGTH]);
934   acc.printfFlags = SQLITE_PRINTF_INTERNAL;
935   sqlite3VXPrintf(&acc, zFormat, ap);
936   z = sqlite3StrAccumFinish(&acc);
937   if( acc.accError==STRACCUM_NOMEM ){
938     sqlite3OomFault(db);
939   }
940   return z;
941 }
942 
943 /*
944 ** Print into memory obtained from sqliteMalloc().  Use the internal
945 ** %-conversion extensions.
946 */
947 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
948   va_list ap;
949   char *z;
950   va_start(ap, zFormat);
951   z = sqlite3VMPrintf(db, zFormat, ap);
952   va_end(ap);
953   return z;
954 }
955 
956 /*
957 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
958 ** %-conversion extensions.
959 */
960 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
961   char *z;
962   char zBase[SQLITE_PRINT_BUF_SIZE];
963   StrAccum acc;
964 
965 #ifdef SQLITE_ENABLE_API_ARMOR
966   if( zFormat==0 ){
967     (void)SQLITE_MISUSE_BKPT;
968     return 0;
969   }
970 #endif
971 #ifndef SQLITE_OMIT_AUTOINIT
972   if( sqlite3_initialize() ) return 0;
973 #endif
974   sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
975   sqlite3VXPrintf(&acc, zFormat, ap);
976   z = sqlite3StrAccumFinish(&acc);
977   return z;
978 }
979 
980 /*
981 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
982 ** %-conversion extensions.
983 */
984 char *sqlite3_mprintf(const char *zFormat, ...){
985   va_list ap;
986   char *z;
987 #ifndef SQLITE_OMIT_AUTOINIT
988   if( sqlite3_initialize() ) return 0;
989 #endif
990   va_start(ap, zFormat);
991   z = sqlite3_vmprintf(zFormat, ap);
992   va_end(ap);
993   return z;
994 }
995 
996 /*
997 ** sqlite3_snprintf() works like snprintf() except that it ignores the
998 ** current locale settings.  This is important for SQLite because we
999 ** are not able to use a "," as the decimal point in place of "." as
1000 ** specified by some locales.
1001 **
1002 ** Oops:  The first two arguments of sqlite3_snprintf() are backwards
1003 ** from the snprintf() standard.  Unfortunately, it is too late to change
1004 ** this without breaking compatibility, so we just have to live with the
1005 ** mistake.
1006 **
1007 ** sqlite3_vsnprintf() is the varargs version.
1008 */
1009 char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
1010   StrAccum acc;
1011   if( n<=0 ) return zBuf;
1012 #ifdef SQLITE_ENABLE_API_ARMOR
1013   if( zBuf==0 || zFormat==0 ) {
1014     (void)SQLITE_MISUSE_BKPT;
1015     if( zBuf ) zBuf[0] = 0;
1016     return zBuf;
1017   }
1018 #endif
1019   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
1020   sqlite3VXPrintf(&acc, zFormat, ap);
1021   zBuf[acc.nChar] = 0;
1022   return zBuf;
1023 }
1024 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
1025   char *z;
1026   va_list ap;
1027   va_start(ap,zFormat);
1028   z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);
1029   va_end(ap);
1030   return z;
1031 }
1032 
1033 /*
1034 ** This is the routine that actually formats the sqlite3_log() message.
1035 ** We house it in a separate routine from sqlite3_log() to avoid using
1036 ** stack space on small-stack systems when logging is disabled.
1037 **
1038 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
1039 ** allocate memory because it might be called while the memory allocator
1040 ** mutex is held.
1041 **
1042 ** sqlite3VXPrintf() might ask for *temporary* memory allocations for
1043 ** certain format characters (%q) or for very large precisions or widths.
1044 ** Care must be taken that any sqlite3_log() calls that occur while the
1045 ** memory mutex is held do not use these mechanisms.
1046 */
1047 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
1048   StrAccum acc;                          /* String accumulator */
1049   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
1050 
1051   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
1052   sqlite3VXPrintf(&acc, zFormat, ap);
1053   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
1054                            sqlite3StrAccumFinish(&acc));
1055 }
1056 
1057 /*
1058 ** Format and write a message to the log if logging is enabled.
1059 */
1060 void sqlite3_log(int iErrCode, const char *zFormat, ...){
1061   va_list ap;                             /* Vararg list */
1062   if( sqlite3GlobalConfig.xLog ){
1063     va_start(ap, zFormat);
1064     renderLogMsg(iErrCode, zFormat, ap);
1065     va_end(ap);
1066   }
1067 }
1068 
1069 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
1070 /*
1071 ** A version of printf() that understands %lld.  Used for debugging.
1072 ** The printf() built into some versions of windows does not understand %lld
1073 ** and segfaults if you give it a long long int.
1074 */
1075 void sqlite3DebugPrintf(const char *zFormat, ...){
1076   va_list ap;
1077   StrAccum acc;
1078   char zBuf[500];
1079   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
1080   va_start(ap,zFormat);
1081   sqlite3VXPrintf(&acc, zFormat, ap);
1082   va_end(ap);
1083   sqlite3StrAccumFinish(&acc);
1084   fprintf(stdout,"%s", zBuf);
1085   fflush(stdout);
1086 }
1087 #endif
1088 
1089 
1090 /*
1091 ** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
1092 ** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
1093 */
1094 void sqlite3XPrintf(StrAccum *p, const char *zFormat, ...){
1095   va_list ap;
1096   va_start(ap,zFormat);
1097   sqlite3VXPrintf(p, zFormat, ap);
1098   va_end(ap);
1099 }
1100