xref: /sqlite-3.40.0/src/printf.c (revision a408adc5)
1 /*
2 ** The "printf" code that follows dates from the 1980's.  It is in
3 ** the public domain.  The original comments are included here for
4 ** completeness.  They are very out-of-date but might be useful as
5 ** an historical reference.  Most of the "enhancements" have been backed
6 ** out so that the functionality is now the same as standard printf().
7 **
8 **************************************************************************
9 **
10 ** The following modules is an enhanced replacement for the "printf" subroutines
11 ** found in the standard C library.  The following enhancements are
12 ** supported:
13 **
14 **      +  Additional functions.  The standard set of "printf" functions
15 **         includes printf, fprintf, sprintf, vprintf, vfprintf, and
16 **         vsprintf.  This module adds the following:
17 **
18 **           *  snprintf -- Works like sprintf, but has an extra argument
19 **                          which is the size of the buffer written to.
20 **
21 **           *  mprintf --  Similar to sprintf.  Writes output to memory
22 **                          obtained from malloc.
23 **
24 **           *  xprintf --  Calls a function to dispose of output.
25 **
26 **           *  nprintf --  No output, but returns the number of characters
27 **                          that would have been output by printf.
28 **
29 **           *  A v- version (ex: vsnprintf) of every function is also
30 **              supplied.
31 **
32 **      +  A few extensions to the formatting notation are supported:
33 **
34 **           *  The "=" flag (similar to "-") causes the output to be
35 **              be centered in the appropriately sized field.
36 **
37 **           *  The %b field outputs an integer in binary notation.
38 **
39 **           *  The %c field now accepts a precision.  The character output
40 **              is repeated by the number of times the precision specifies.
41 **
42 **           *  The %' field works like %c, but takes as its character the
43 **              next character of the format string, instead of the next
44 **              argument.  For example,  printf("%.78'-")  prints 78 minus
45 **              signs, the same as  printf("%.78c",'-').
46 **
47 **      +  When compiled using GCC on a SPARC, this version of printf is
48 **         faster than the library printf for SUN OS 4.1.
49 **
50 **      +  All functions are fully reentrant.
51 **
52 */
53 #include "sqliteInt.h"
54 #include <math.h>
55 
56 /*
57 ** Conversion types fall into various categories as defined by the
58 ** following enumeration.
59 */
60 #define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
61 #define etFLOAT       2 /* Floating point.  %f */
62 #define etEXP         3 /* Exponentional notation. %e and %E */
63 #define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
64 #define etSIZE        5 /* Return number of characters processed so far. %n */
65 #define etSTRING      6 /* Strings. %s */
66 #define etDYNSTRING   7 /* Dynamically allocated strings. %z */
67 #define etPERCENT     8 /* Percent symbol. %% */
68 #define etCHARX       9 /* Characters. %c */
69 /* The rest are extensions, not normally found in printf() */
70 #define etCHARLIT    10 /* Literal characters.  %' */
71 #define etSQLESCAPE  11 /* Strings with '\'' doubled.  %q */
72 #define etSQLESCAPE2 12 /* Strings with '\'' doubled and enclosed in '',
73                           NULL pointers replaced by SQL NULL.  %Q */
74 #define etTOKEN      13 /* a pointer to a Token structure */
75 #define etSRCLIST    14 /* a pointer to a SrcList */
76 #define etPOINTER    15 /* The %p conversion */
77 
78 
79 /*
80 ** An "etByte" is an 8-bit unsigned value.
81 */
82 typedef unsigned char etByte;
83 
84 /*
85 ** Each builtin conversion character (ex: the 'd' in "%d") is described
86 ** by an instance of the following structure
87 */
88 typedef struct et_info {   /* Information about each format field */
89   char fmttype;            /* The format field code letter */
90   etByte base;             /* The base for radix conversion */
91   etByte flags;            /* One or more of FLAG_ constants below */
92   etByte type;             /* Conversion paradigm */
93   etByte charset;          /* Offset into aDigits[] of the digits string */
94   etByte prefix;           /* Offset into aPrefix[] of the prefix string */
95 } et_info;
96 
97 /*
98 ** Allowed values for et_info.flags
99 */
100 #define FLAG_SIGNED  1     /* True if the value to convert is signed */
101 #define FLAG_INTERN  2     /* True if for internal use only */
102 #define FLAG_STRING  4     /* Allow infinity precision */
103 
104 
105 /*
106 ** The following table is searched linearly, so it is good to put the
107 ** most frequently used conversion types first.
108 */
109 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
110 static const char aPrefix[] = "-x0\000X0";
111 static const et_info fmtinfo[] = {
112   {  'd', 10, 1, etRADIX,      0,  0 },
113   {  's',  0, 4, etSTRING,     0,  0 },
114   {  'g',  0, 1, etGENERIC,    30, 0 },
115   {  'z',  0, 6, etDYNSTRING,  0,  0 },
116   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
117   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
118   {  'c',  0, 0, etCHARX,      0,  0 },
119   {  'o',  8, 0, etRADIX,      0,  2 },
120   {  'u', 10, 0, etRADIX,      0,  0 },
121   {  'x', 16, 0, etRADIX,      16, 1 },
122   {  'X', 16, 0, etRADIX,      0,  4 },
123 #ifndef SQLITE_OMIT_FLOATING_POINT
124   {  'f',  0, 1, etFLOAT,      0,  0 },
125   {  'e',  0, 1, etEXP,        30, 0 },
126   {  'E',  0, 1, etEXP,        14, 0 },
127   {  'G',  0, 1, etGENERIC,    14, 0 },
128 #endif
129   {  'i', 10, 1, etRADIX,      0,  0 },
130   {  'n',  0, 0, etSIZE,       0,  0 },
131   {  '%',  0, 0, etPERCENT,    0,  0 },
132   {  'p', 16, 0, etPOINTER,    0,  1 },
133   {  'T',  0, 2, etTOKEN,      0,  0 },
134   {  'S',  0, 2, etSRCLIST,    0,  0 },
135 };
136 #define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))
137 
138 /*
139 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
140 ** conversions will work.
141 */
142 #ifndef SQLITE_OMIT_FLOATING_POINT
143 /*
144 ** "*val" is a double such that 0.1 <= *val < 10.0
145 ** Return the ascii code for the leading digit of *val, then
146 ** multiply "*val" by 10.0 to renormalize.
147 **
148 ** Example:
149 **     input:     *val = 3.14159
150 **     output:    *val = 1.4159    function return = '3'
151 **
152 ** The counter *cnt is incremented each time.  After counter exceeds
153 ** 16 (the number of significant digits in a 64-bit float) '0' is
154 ** always returned.
155 */
156 static int et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
157   int digit;
158   LONGDOUBLE_TYPE d;
159   if( (*cnt)++ >= 16 ) return '0';
160   digit = (int)*val;
161   d = digit;
162   digit += '0';
163   *val = (*val - d)*10.0;
164   return digit;
165 }
166 #endif /* SQLITE_OMIT_FLOATING_POINT */
167 
168 /*
169 ** On machines with a small stack size, you can redefine the
170 ** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
171 ** smaller values some %f conversions may go into an infinite loop.
172 */
173 #ifndef SQLITE_PRINT_BUF_SIZE
174 # define SQLITE_PRINT_BUF_SIZE 350
175 #endif
176 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
177 
178 /*
179 ** The root program.  All variations call this core.
180 **
181 ** INPUTS:
182 **   func   This is a pointer to a function taking three arguments
183 **            1. A pointer to anything.  Same as the "arg" parameter.
184 **            2. A pointer to the list of characters to be output
185 **               (Note, this list is NOT null terminated.)
186 **            3. An integer number of characters to be output.
187 **               (Note: This number might be zero.)
188 **
189 **   arg    This is the pointer to anything which will be passed as the
190 **          first argument to "func".  Use it for whatever you like.
191 **
192 **   fmt    This is the format string, as in the usual print.
193 **
194 **   ap     This is a pointer to a list of arguments.  Same as in
195 **          vfprint.
196 **
197 ** OUTPUTS:
198 **          The return value is the total number of characters sent to
199 **          the function "func".  Returns -1 on a error.
200 **
201 ** Note that the order in which automatic variables are declared below
202 ** seems to make a big difference in determining how fast this beast
203 ** will run.
204 */
205 static int vxprintf(
206   void (*func)(void*,const char*,int),     /* Consumer of text */
207   void *arg,                         /* First argument to the consumer */
208   int useExtended,                   /* Allow extended %-conversions */
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 count;                 /* Total number of characters output */
218   int width;                 /* Width of the current field */
219   etByte flag_leftjustify;   /* True if "-" flag is present */
220   etByte flag_plussign;      /* True if "+" flag is present */
221   etByte flag_blanksign;     /* True if " " flag is present */
222   etByte flag_alternateform; /* True if "#" flag is present */
223   etByte flag_altform2;      /* True if "!" flag is present */
224   etByte flag_zeropad;       /* True if field width constant starts with zero */
225   etByte flag_long;          /* True if "l" flag is present */
226   etByte flag_longlong;      /* True if the "ll" flag is present */
227   etByte done;               /* Loop termination flag */
228   sqlite_uint64 longvalue;   /* Value for integer types */
229   LONGDOUBLE_TYPE realvalue; /* Value for real types */
230   const et_info *infop;      /* Pointer to the appropriate info structure */
231   char buf[etBUFSIZE];       /* Conversion buffer */
232   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
233   etByte errorflag = 0;      /* True if an error is encountered */
234   etByte xtype;              /* Conversion paradigm */
235   char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
236   static const char spaces[] =
237    "                                                                         ";
238 #define etSPACESIZE (sizeof(spaces)-1)
239 #ifndef SQLITE_OMIT_FLOATING_POINT
240   int  exp, e2;              /* exponent of real numbers */
241   double rounder;            /* Used for rounding floating point values */
242   etByte flag_dp;            /* True if decimal point should be shown */
243   etByte flag_rtz;           /* True if trailing zeros should be removed */
244   etByte flag_exp;           /* True to force display of the exponent */
245   int nsd;                   /* Number of significant digits returned */
246 #endif
247 
248   func(arg,"",0);
249   count = length = 0;
250   bufpt = 0;
251   for(; (c=(*fmt))!=0; ++fmt){
252     if( c!='%' ){
253       int amt;
254       bufpt = (char *)fmt;
255       amt = 1;
256       while( (c=(*++fmt))!='%' && c!=0 ) amt++;
257       (*func)(arg,bufpt,amt);
258       count += amt;
259       if( c==0 ) break;
260     }
261     if( (c=(*++fmt))==0 ){
262       errorflag = 1;
263       (*func)(arg,"%",1);
264       count++;
265       break;
266     }
267     /* Find out what flags are present */
268     flag_leftjustify = flag_plussign = flag_blanksign =
269      flag_alternateform = flag_altform2 = flag_zeropad = 0;
270     done = 0;
271     do{
272       switch( c ){
273         case '-':   flag_leftjustify = 1;     break;
274         case '+':   flag_plussign = 1;        break;
275         case ' ':   flag_blanksign = 1;       break;
276         case '#':   flag_alternateform = 1;   break;
277         case '!':   flag_altform2 = 1;        break;
278         case '0':   flag_zeropad = 1;         break;
279         default:    done = 1;                 break;
280       }
281     }while( !done && (c=(*++fmt))!=0 );
282     /* Get the field width */
283     width = 0;
284     if( c=='*' ){
285       width = va_arg(ap,int);
286       if( width<0 ){
287         flag_leftjustify = 1;
288         width = -width;
289       }
290       c = *++fmt;
291     }else{
292       while( c>='0' && c<='9' ){
293         width = width*10 + c - '0';
294         c = *++fmt;
295       }
296     }
297     if( width > etBUFSIZE-10 ){
298       width = etBUFSIZE-10;
299     }
300     /* Get the precision */
301     if( c=='.' ){
302       precision = 0;
303       c = *++fmt;
304       if( c=='*' ){
305         precision = va_arg(ap,int);
306         if( precision<0 ) precision = -precision;
307         c = *++fmt;
308       }else{
309         while( c>='0' && c<='9' ){
310           precision = precision*10 + c - '0';
311           c = *++fmt;
312         }
313       }
314     }else{
315       precision = -1;
316     }
317     /* Get the conversion type modifier */
318     if( c=='l' ){
319       flag_long = 1;
320       c = *++fmt;
321       if( c=='l' ){
322         flag_longlong = 1;
323         c = *++fmt;
324       }else{
325         flag_longlong = 0;
326       }
327     }else{
328       flag_long = flag_longlong = 0;
329     }
330     /* Fetch the info entry for the field */
331     infop = 0;
332     for(idx=0; idx<etNINFO; idx++){
333       if( c==fmtinfo[idx].fmttype ){
334         infop = &fmtinfo[idx];
335         if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
336           xtype = infop->type;
337         }else{
338           return -1;
339         }
340         break;
341       }
342     }
343     zExtra = 0;
344     if( infop==0 ){
345       return -1;
346     }
347 
348 
349     /* Limit the precision to prevent overflowing buf[] during conversion */
350     if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
351       precision = etBUFSIZE-40;
352     }
353 
354     /*
355     ** At this point, variables are initialized as follows:
356     **
357     **   flag_alternateform          TRUE if a '#' is present.
358     **   flag_altform2               TRUE if a '!' is present.
359     **   flag_plussign               TRUE if a '+' is present.
360     **   flag_leftjustify            TRUE if a '-' is present or if the
361     **                               field width was negative.
362     **   flag_zeropad                TRUE if the width began with 0.
363     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
364     **                               the conversion character.
365     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
366     **                               the conversion character.
367     **   flag_blanksign              TRUE if a ' ' is present.
368     **   width                       The specified field width.  This is
369     **                               always non-negative.  Zero is the default.
370     **   precision                   The specified precision.  The default
371     **                               is -1.
372     **   xtype                       The class of the conversion.
373     **   infop                       Pointer to the appropriate info struct.
374     */
375     switch( xtype ){
376       case etPOINTER:
377         flag_longlong = sizeof(char*)==sizeof(i64);
378         flag_long = sizeof(char*)==sizeof(long int);
379         /* Fall through into the next case */
380       case etRADIX:
381         if( infop->flags & FLAG_SIGNED ){
382           i64 v;
383           if( flag_longlong )   v = va_arg(ap,i64);
384           else if( flag_long )  v = va_arg(ap,long int);
385           else                  v = va_arg(ap,int);
386           if( v<0 ){
387             longvalue = -v;
388             prefix = '-';
389           }else{
390             longvalue = v;
391             if( flag_plussign )        prefix = '+';
392             else if( flag_blanksign )  prefix = ' ';
393             else                       prefix = 0;
394           }
395         }else{
396           if( flag_longlong )   longvalue = va_arg(ap,u64);
397           else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
398           else                  longvalue = va_arg(ap,unsigned int);
399           prefix = 0;
400         }
401         if( longvalue==0 ) flag_alternateform = 0;
402         if( flag_zeropad && precision<width-(prefix!=0) ){
403           precision = width-(prefix!=0);
404         }
405         bufpt = &buf[etBUFSIZE-1];
406         {
407           register const char *cset;      /* Use registers for speed */
408           register int base;
409           cset = &aDigits[infop->charset];
410           base = infop->base;
411           do{                                           /* Convert to ascii */
412             *(--bufpt) = cset[longvalue%base];
413             longvalue = longvalue/base;
414           }while( longvalue>0 );
415         }
416         length = &buf[etBUFSIZE-1]-bufpt;
417         for(idx=precision-length; idx>0; idx--){
418           *(--bufpt) = '0';                             /* Zero pad */
419         }
420         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
421         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
422           const char *pre;
423           char x;
424           pre = &aPrefix[infop->prefix];
425           if( *bufpt!=pre[0] ){
426             for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
427           }
428         }
429         length = &buf[etBUFSIZE-1]-bufpt;
430         break;
431       case etFLOAT:
432       case etEXP:
433       case etGENERIC:
434         realvalue = va_arg(ap,double);
435 #ifndef SQLITE_OMIT_FLOATING_POINT
436         if( precision<0 ) precision = 6;         /* Set default precision */
437         if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
438         if( realvalue<0.0 ){
439           realvalue = -realvalue;
440           prefix = '-';
441         }else{
442           if( flag_plussign )          prefix = '+';
443           else if( flag_blanksign )    prefix = ' ';
444           else                         prefix = 0;
445         }
446         if( xtype==etGENERIC && precision>0 ) precision--;
447 #if 0
448         /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
449         for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
450 #else
451         /* It makes more sense to use 0.5 */
452         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
453 #endif
454         if( xtype==etFLOAT ) realvalue += rounder;
455         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
456         exp = 0;
457         if( isnan(realvalue) ){
458           bufpt = "NaN";
459           length = 3;
460           break;
461         }
462         if( realvalue>0.0 ){
463           while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
464           while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
465           while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
466           while( realvalue<1e-8 && exp>=-350 ){ realvalue *= 1e8; exp-=8; }
467           while( realvalue<1.0 && exp>=-350 ){ realvalue *= 10.0; exp--; }
468           if( exp>350 || exp<-350 ){
469             if( prefix=='-' ){
470               bufpt = "-Inf";
471             }else if( prefix=='+' ){
472               bufpt = "+Inf";
473             }else{
474               bufpt = "Inf";
475             }
476             length = strlen(bufpt);
477             break;
478           }
479         }
480         bufpt = buf;
481         /*
482         ** If the field type is etGENERIC, then convert to either etEXP
483         ** or etFLOAT, as appropriate.
484         */
485         flag_exp = xtype==etEXP;
486         if( xtype!=etFLOAT ){
487           realvalue += rounder;
488           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
489         }
490         if( xtype==etGENERIC ){
491           flag_rtz = !flag_alternateform;
492           if( exp<-4 || exp>precision ){
493             xtype = etEXP;
494           }else{
495             precision = precision - exp;
496             xtype = etFLOAT;
497           }
498         }else{
499           flag_rtz = 0;
500         }
501         if( xtype==etEXP ){
502           e2 = 0;
503         }else{
504           e2 = exp;
505         }
506         nsd = 0;
507         flag_dp = (precision>0) | flag_alternateform | flag_altform2;
508         /* The sign in front of the number */
509         if( prefix ){
510           *(bufpt++) = prefix;
511         }
512         /* Digits prior to the decimal point */
513         if( e2<0 ){
514           *(bufpt++) = '0';
515         }else{
516           for(; e2>=0; e2--){
517             *(bufpt++) = et_getdigit(&realvalue,&nsd);
518           }
519         }
520         /* The decimal point */
521         if( flag_dp ){
522           *(bufpt++) = '.';
523         }
524         /* "0" digits after the decimal point but before the first
525         ** significant digit of the number */
526         for(e2++; e2<0 && precision>0; precision--, e2++){
527           *(bufpt++) = '0';
528         }
529         /* Significant digits after the decimal point */
530         while( (precision--)>0 ){
531           *(bufpt++) = et_getdigit(&realvalue,&nsd);
532         }
533         /* Remove trailing zeros and the "." if no digits follow the "." */
534         if( flag_rtz && flag_dp ){
535           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
536           assert( bufpt>buf );
537           if( bufpt[-1]=='.' ){
538             if( flag_altform2 ){
539               *(bufpt++) = '0';
540             }else{
541               *(--bufpt) = 0;
542             }
543           }
544         }
545         /* Add the "eNNN" suffix */
546         if( flag_exp || (xtype==etEXP && exp) ){
547           *(bufpt++) = aDigits[infop->charset];
548           if( exp<0 ){
549             *(bufpt++) = '-'; exp = -exp;
550           }else{
551             *(bufpt++) = '+';
552           }
553           if( exp>=100 ){
554             *(bufpt++) = (exp/100)+'0';                /* 100's digit */
555             exp %= 100;
556           }
557           *(bufpt++) = exp/10+'0';                     /* 10's digit */
558           *(bufpt++) = exp%10+'0';                     /* 1's digit */
559         }
560         *bufpt = 0;
561 
562         /* The converted number is in buf[] and zero terminated. Output it.
563         ** Note that the number is in the usual order, not reversed as with
564         ** integer conversions. */
565         length = bufpt-buf;
566         bufpt = buf;
567 
568         /* Special case:  Add leading zeros if the flag_zeropad flag is
569         ** set and we are not left justified */
570         if( flag_zeropad && !flag_leftjustify && length < width){
571           int i;
572           int nPad = width - length;
573           for(i=width; i>=nPad; i--){
574             bufpt[i] = bufpt[i-nPad];
575           }
576           i = prefix!=0;
577           while( nPad-- ) bufpt[i++] = '0';
578           length = width;
579         }
580 #endif
581         break;
582       case etSIZE:
583         *(va_arg(ap,int*)) = count;
584         length = width = 0;
585         break;
586       case etPERCENT:
587         buf[0] = '%';
588         bufpt = buf;
589         length = 1;
590         break;
591       case etCHARLIT:
592       case etCHARX:
593         c = buf[0] = (xtype==etCHARX ? va_arg(ap,int) : *++fmt);
594         if( precision>=0 ){
595           for(idx=1; idx<precision; idx++) buf[idx] = c;
596           length = precision;
597         }else{
598           length =1;
599         }
600         bufpt = buf;
601         break;
602       case etSTRING:
603       case etDYNSTRING:
604         bufpt = va_arg(ap,char*);
605         if( bufpt==0 ){
606           bufpt = "";
607         }else if( xtype==etDYNSTRING ){
608           zExtra = bufpt;
609         }
610         length = strlen(bufpt);
611         if( precision>=0 && precision<length ) length = precision;
612         break;
613       case etSQLESCAPE:
614       case etSQLESCAPE2: {
615         int i, j, n, ch, isnull;
616         int needQuote;
617         char *escarg = va_arg(ap,char*);
618         isnull = escarg==0;
619         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
620         for(i=n=0; (ch=escarg[i])!=0; i++){
621           if( ch=='\'' )  n++;
622         }
623         needQuote = !isnull && xtype==etSQLESCAPE2;
624         n += i + 1 + needQuote*2;
625         if( n>etBUFSIZE ){
626           bufpt = zExtra = sqliteMalloc( n );
627           if( bufpt==0 ) return -1;
628         }else{
629           bufpt = buf;
630         }
631         j = 0;
632         if( needQuote ) bufpt[j++] = '\'';
633         for(i=0; (ch=escarg[i])!=0; i++){
634           bufpt[j++] = ch;
635           if( ch=='\'' ) bufpt[j++] = ch;
636         }
637         if( needQuote ) bufpt[j++] = '\'';
638         bufpt[j] = 0;
639         length = j;
640         /* The precision is ignored on %q and %Q */
641         /* if( precision>=0 && precision<length ) length = precision; */
642         break;
643       }
644       case etTOKEN: {
645         Token *pToken = va_arg(ap, Token*);
646         if( pToken && pToken->z ){
647           (*func)(arg, (char*)pToken->z, pToken->n);
648         }
649         length = width = 0;
650         break;
651       }
652       case etSRCLIST: {
653         SrcList *pSrc = va_arg(ap, SrcList*);
654         int k = va_arg(ap, int);
655         struct SrcList_item *pItem = &pSrc->a[k];
656         assert( k>=0 && k<pSrc->nSrc );
657         if( pItem->zDatabase && pItem->zDatabase[0] ){
658           (*func)(arg, pItem->zDatabase, strlen(pItem->zDatabase));
659           (*func)(arg, ".", 1);
660         }
661         (*func)(arg, pItem->zName, strlen(pItem->zName));
662         length = width = 0;
663         break;
664       }
665     }/* End switch over the format type */
666     /*
667     ** The text of the conversion is pointed to by "bufpt" and is
668     ** "length" characters long.  The field width is "width".  Do
669     ** the output.
670     */
671     if( !flag_leftjustify ){
672       register int nspace;
673       nspace = width-length;
674       if( nspace>0 ){
675         count += nspace;
676         while( nspace>=etSPACESIZE ){
677           (*func)(arg,spaces,etSPACESIZE);
678           nspace -= etSPACESIZE;
679         }
680         if( nspace>0 ) (*func)(arg,spaces,nspace);
681       }
682     }
683     if( length>0 ){
684       (*func)(arg,bufpt,length);
685       count += length;
686     }
687     if( flag_leftjustify ){
688       register int nspace;
689       nspace = width-length;
690       if( nspace>0 ){
691         count += nspace;
692         while( nspace>=etSPACESIZE ){
693           (*func)(arg,spaces,etSPACESIZE);
694           nspace -= etSPACESIZE;
695         }
696         if( nspace>0 ) (*func)(arg,spaces,nspace);
697       }
698     }
699     if( zExtra ){
700       sqliteFree(zExtra);
701     }
702   }/* End for loop over the format string */
703   return errorflag ? -1 : count;
704 } /* End of function */
705 
706 
707 /* This structure is used to store state information about the
708 ** write to memory that is currently in progress.
709 */
710 struct sgMprintf {
711   char *zBase;     /* A base allocation */
712   char *zText;     /* The string collected so far */
713   int  nChar;      /* Length of the string so far */
714   int  nTotal;     /* Output size if unconstrained */
715   int  nAlloc;     /* Amount of space allocated in zText */
716   void *(*xRealloc)(void*,int);  /* Function used to realloc memory */
717 };
718 
719 /*
720 ** This function implements the callback from vxprintf.
721 **
722 ** This routine add nNewChar characters of text in zNewText to
723 ** the sgMprintf structure pointed to by "arg".
724 */
725 static void mout(void *arg, const char *zNewText, int nNewChar){
726   struct sgMprintf *pM = (struct sgMprintf*)arg;
727   pM->nTotal += nNewChar;
728   if( pM->nChar + nNewChar + 1 > pM->nAlloc ){
729     if( pM->xRealloc==0 ){
730       nNewChar =  pM->nAlloc - pM->nChar - 1;
731     }else{
732       int nAlloc = pM->nChar + nNewChar*2 + 1;
733       if( pM->zText==pM->zBase ){
734         pM->zText = pM->xRealloc(0, nAlloc);
735         if( pM->zText && pM->nChar ){
736           memcpy(pM->zText, pM->zBase, pM->nChar);
737         }
738       }else{
739         char *zNew;
740         zNew = pM->xRealloc(pM->zText, nAlloc);
741         if( zNew ){
742           pM->zText = zNew;
743         }else{
744           return;
745         }
746       }
747       pM->nAlloc = nAlloc;
748     }
749   }
750   if( pM->zText ){
751     if( nNewChar>0 ){
752       memcpy(&pM->zText[pM->nChar], zNewText, nNewChar);
753       pM->nChar += nNewChar;
754     }
755     pM->zText[pM->nChar] = 0;
756   }
757 }
758 
759 /*
760 ** This routine is a wrapper around xprintf() that invokes mout() as
761 ** the consumer.
762 */
763 static char *base_vprintf(
764   void *(*xRealloc)(void*,int),   /* Routine to realloc memory. May be NULL */
765   int useInternal,                /* Use internal %-conversions if true */
766   char *zInitBuf,                 /* Initially write here, before mallocing */
767   int nInitBuf,                   /* Size of zInitBuf[] */
768   const char *zFormat,            /* format string */
769   va_list ap                      /* arguments */
770 ){
771   struct sgMprintf sM;
772   sM.zBase = sM.zText = zInitBuf;
773   sM.nChar = sM.nTotal = 0;
774   sM.nAlloc = nInitBuf;
775   sM.xRealloc = xRealloc;
776   vxprintf(mout, &sM, useInternal, zFormat, ap);
777   if( xRealloc ){
778     if( sM.zText==sM.zBase ){
779       sM.zText = xRealloc(0, sM.nChar+1);
780       if( sM.zText ){
781         memcpy(sM.zText, sM.zBase, sM.nChar+1);
782       }
783     }else if( sM.nAlloc>sM.nChar+10 ){
784       char *zNew = xRealloc(sM.zText, sM.nChar+1);
785       if( zNew ){
786         sM.zText = zNew;
787       }
788     }
789   }
790   return sM.zText;
791 }
792 
793 /*
794 ** Realloc that is a real function, not a macro.
795 */
796 static void *printf_realloc(void *old, int size){
797   return sqliteRealloc(old,size);
798 }
799 
800 /*
801 ** Print into memory obtained from sqliteMalloc().  Use the internal
802 ** %-conversion extensions.
803 */
804 char *sqlite3VMPrintf(const char *zFormat, va_list ap){
805   char zBase[SQLITE_PRINT_BUF_SIZE];
806   return base_vprintf(printf_realloc, 1, zBase, sizeof(zBase), zFormat, ap);
807 }
808 
809 /*
810 ** Print into memory obtained from sqliteMalloc().  Use the internal
811 ** %-conversion extensions.
812 */
813 char *sqlite3MPrintf(const char *zFormat, ...){
814   va_list ap;
815   char *z;
816   char zBase[SQLITE_PRINT_BUF_SIZE];
817   va_start(ap, zFormat);
818   z = base_vprintf(printf_realloc, 1, zBase, sizeof(zBase), zFormat, ap);
819   va_end(ap);
820   return z;
821 }
822 
823 /*
824 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
825 ** %-conversion extensions.
826 */
827 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
828   char zBase[SQLITE_PRINT_BUF_SIZE];
829   return base_vprintf(sqlite3_realloc, 0, zBase, sizeof(zBase), zFormat, ap);
830 }
831 
832 /*
833 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
834 ** %-conversion extensions.
835 */
836 char *sqlite3_mprintf(const char *zFormat, ...){
837   va_list ap;
838   char *z;
839   va_start(ap, zFormat);
840   z = sqlite3_vmprintf(zFormat, ap);
841   va_end(ap);
842   return z;
843 }
844 
845 /*
846 ** sqlite3_snprintf() works like snprintf() except that it ignores the
847 ** current locale settings.  This is important for SQLite because we
848 ** are not able to use a "," as the decimal point in place of "." as
849 ** specified by some locales.
850 */
851 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
852   char *z;
853   va_list ap;
854 
855   if( n<=0 ){
856     return zBuf;
857   }
858   zBuf[0] = 0;
859   va_start(ap,zFormat);
860   z = base_vprintf(0, 0, zBuf, n, zFormat, ap);
861   va_end(ap);
862   return z;
863 }
864 
865 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
866 /*
867 ** A version of printf() that understands %lld.  Used for debugging.
868 ** The printf() built into some versions of windows does not understand %lld
869 ** and segfaults if you give it a long long int.
870 */
871 void sqlite3DebugPrintf(const char *zFormat, ...){
872   extern int getpid(void);
873   va_list ap;
874   char zBuf[500];
875   va_start(ap, zFormat);
876   base_vprintf(0, 0, zBuf, sizeof(zBuf), zFormat, ap);
877   va_end(ap);
878   fprintf(stdout,"%s", zBuf);
879   fflush(stdout);
880 }
881 #endif
882