xref: /sqlite-3.40.0/src/printf.c (revision 4dcbdbff)
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  They are very out-of-date but might be useful as
5 ** an historical reference.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 
55 /*
56 ** Conversion types fall into various categories as defined by the
57 ** following enumeration.
58 */
59 #define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
60 #define etFLOAT       2 /* Floating point.  %f */
61 #define etEXP         3 /* Exponentional notation. %e and %E */
62 #define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
63 #define etSIZE        5 /* Return number of characters processed so far. %n */
64 #define etSTRING      6 /* Strings. %s */
65 #define etDYNSTRING   7 /* Dynamically allocated strings. %z */
66 #define etPERCENT     8 /* Percent symbol. %% */
67 #define etCHARX       9 /* Characters. %c */
68 #define etERROR      10 /* Used to indicate no such conversion type */
69 /* The rest are extensions, not normally found in printf() */
70 #define etCHARLIT    11 /* Literal characters.  %' */
71 #define etSQLESCAPE  12 /* Strings with '\'' doubled.  %q */
72 #define etSQLESCAPE2 13 /* Strings with '\'' doubled and enclosed in '',
73                           NULL pointers replaced by SQL NULL.  %Q */
74 #define etTOKEN      14 /* a pointer to a Token structure */
75 #define etSRCLIST    15 /* a pointer to a SrcList */
76 #define etPOINTER    16 /* 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   {  'z',  0, 6, etDYNSTRING,  0,  0 },
115   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
116   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
117   {  'c',  0, 0, etCHARX,      0,  0 },
118   {  'o',  8, 0, etRADIX,      0,  2 },
119   {  'u', 10, 0, etRADIX,      0,  0 },
120   {  'x', 16, 0, etRADIX,      16, 1 },
121   {  'X', 16, 0, etRADIX,      0,  4 },
122   {  'f',  0, 1, etFLOAT,      0,  0 },
123   {  'e',  0, 1, etEXP,        30, 0 },
124   {  'E',  0, 1, etEXP,        14, 0 },
125   {  'g',  0, 1, etGENERIC,    30, 0 },
126   {  'G',  0, 1, etGENERIC,    14, 0 },
127   {  'i', 10, 1, etRADIX,      0,  0 },
128   {  'n',  0, 0, etSIZE,       0,  0 },
129   {  '%',  0, 0, etPERCENT,    0,  0 },
130   {  'p', 16, 0, etPOINTER,    0,  1 },
131   {  'T',  0, 2, etTOKEN,      0,  0 },
132   {  'S',  0, 2, etSRCLIST,    0,  0 },
133 };
134 #define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))
135 
136 /*
137 ** If NOFLOATINGPOINT is defined, then none of the floating point
138 ** conversions will work.
139 */
140 #ifndef etNOFLOATINGPOINT
141 /*
142 ** "*val" is a double such that 0.1 <= *val < 10.0
143 ** Return the ascii code for the leading digit of *val, then
144 ** multiply "*val" by 10.0 to renormalize.
145 **
146 ** Example:
147 **     input:     *val = 3.14159
148 **     output:    *val = 1.4159    function return = '3'
149 **
150 ** The counter *cnt is incremented each time.  After counter exceeds
151 ** 16 (the number of significant digits in a 64-bit float) '0' is
152 ** always returned.
153 */
154 static int et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
155   int digit;
156   LONGDOUBLE_TYPE d;
157   if( (*cnt)++ >= 16 ) return '0';
158   digit = (int)*val;
159   d = digit;
160   digit += '0';
161   *val = (*val - d)*10.0;
162   return digit;
163 }
164 #endif
165 
166 #define etBUFSIZE 1000  /* Size of the output buffer */
167 
168 /*
169 ** The root program.  All variations call this core.
170 **
171 ** INPUTS:
172 **   func   This is a pointer to a function taking three arguments
173 **            1. A pointer to anything.  Same as the "arg" parameter.
174 **            2. A pointer to the list of characters to be output
175 **               (Note, this list is NOT null terminated.)
176 **            3. An integer number of characters to be output.
177 **               (Note: This number might be zero.)
178 **
179 **   arg    This is the pointer to anything which will be passed as the
180 **          first argument to "func".  Use it for whatever you like.
181 **
182 **   fmt    This is the format string, as in the usual print.
183 **
184 **   ap     This is a pointer to a list of arguments.  Same as in
185 **          vfprint.
186 **
187 ** OUTPUTS:
188 **          The return value is the total number of characters sent to
189 **          the function "func".  Returns -1 on a error.
190 **
191 ** Note that the order in which automatic variables are declared below
192 ** seems to make a big difference in determining how fast this beast
193 ** will run.
194 */
195 static int vxprintf(
196   void (*func)(void*,const char*,int),     /* Consumer of text */
197   void *arg,                         /* First argument to the consumer */
198   int useExtended,                   /* Allow extended %-conversions */
199   const char *fmt,                   /* Format string */
200   va_list ap                         /* arguments */
201 ){
202   int c;                     /* Next character in the format string */
203   char *bufpt;               /* Pointer to the conversion buffer */
204   int precision;             /* Precision of the current field */
205   int length;                /* Length of the field */
206   int idx;                   /* A general purpose loop counter */
207   int count;                 /* Total number of characters output */
208   int width;                 /* Width of the current field */
209   etByte flag_leftjustify;   /* True if "-" flag is present */
210   etByte flag_plussign;      /* True if "+" flag is present */
211   etByte flag_blanksign;     /* True if " " flag is present */
212   etByte flag_alternateform; /* True if "#" flag is present */
213   etByte flag_zeropad;       /* True if field width constant starts with zero */
214   etByte flag_long;          /* True if "l" flag is present */
215   etByte flag_longlong;      /* True if the "ll" flag is present */
216   UINT64_TYPE longvalue;     /* Value for integer types */
217   LONGDOUBLE_TYPE realvalue; /* Value for real types */
218   const et_info *infop;      /* Pointer to the appropriate info structure */
219   char buf[etBUFSIZE];       /* Conversion buffer */
220   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
221   etByte errorflag = 0;      /* True if an error is encountered */
222   etByte xtype;              /* Conversion paradigm */
223   char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
224   static const char spaces[] =
225    "                                                                         ";
226 #define etSPACESIZE (sizeof(spaces)-1)
227 #ifndef etNOFLOATINGPOINT
228   int  exp;                  /* exponent of real numbers */
229   double rounder;            /* Used for rounding floating point values */
230   etByte flag_dp;            /* True if decimal point should be shown */
231   etByte flag_rtz;           /* True if trailing zeros should be removed */
232   etByte flag_exp;           /* True to force display of the exponent */
233   int nsd;                   /* Number of significant digits returned */
234 #endif
235 
236   func(arg,"",0);
237   count = length = 0;
238   bufpt = 0;
239   for(; (c=(*fmt))!=0; ++fmt){
240     if( c!='%' ){
241       int amt;
242       bufpt = (char *)fmt;
243       amt = 1;
244       while( (c=(*++fmt))!='%' && c!=0 ) amt++;
245       (*func)(arg,bufpt,amt);
246       count += amt;
247       if( c==0 ) break;
248     }
249     if( (c=(*++fmt))==0 ){
250       errorflag = 1;
251       (*func)(arg,"%",1);
252       count++;
253       break;
254     }
255     /* Find out what flags are present */
256     flag_leftjustify = flag_plussign = flag_blanksign =
257      flag_alternateform = flag_zeropad = 0;
258     do{
259       switch( c ){
260         case '-':   flag_leftjustify = 1;     c = 0;   break;
261         case '+':   flag_plussign = 1;        c = 0;   break;
262         case ' ':   flag_blanksign = 1;       c = 0;   break;
263         case '#':   flag_alternateform = 1;   c = 0;   break;
264         case '0':   flag_zeropad = 1;         c = 0;   break;
265         default:                                       break;
266       }
267     }while( c==0 && (c=(*++fmt))!=0 );
268     /* Get the field width */
269     width = 0;
270     if( c=='*' ){
271       width = va_arg(ap,int);
272       if( width<0 ){
273         flag_leftjustify = 1;
274         width = -width;
275       }
276       c = *++fmt;
277     }else{
278       while( c>='0' && c<='9' ){
279         width = width*10 + c - '0';
280         c = *++fmt;
281       }
282     }
283     if( width > etBUFSIZE-10 ){
284       width = etBUFSIZE-10;
285     }
286     /* Get the precision */
287     if( c=='.' ){
288       precision = 0;
289       c = *++fmt;
290       if( c=='*' ){
291         precision = va_arg(ap,int);
292         if( precision<0 ) precision = -precision;
293         c = *++fmt;
294       }else{
295         while( c>='0' && c<='9' ){
296           precision = precision*10 + c - '0';
297           c = *++fmt;
298         }
299       }
300     }else{
301       precision = -1;
302     }
303     /* Get the conversion type modifier */
304     if( c=='l' ){
305       flag_long = 1;
306       c = *++fmt;
307       if( c=='l' ){
308         flag_longlong = 1;
309         c = *++fmt;
310       }else{
311         flag_longlong = 0;
312       }
313     }else{
314       flag_long = flag_longlong = 0;
315     }
316     /* Fetch the info entry for the field */
317     infop = 0;
318     xtype = etERROR;
319     for(idx=0; idx<etNINFO; idx++){
320       if( c==fmtinfo[idx].fmttype ){
321         infop = &fmtinfo[idx];
322         if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
323           xtype = infop->type;
324         }
325         break;
326       }
327     }
328     zExtra = 0;
329 
330     /* Limit the precision to prevent overflowing buf[] during conversion */
331     if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
332       precision = etBUFSIZE-40;
333     }
334 
335     /*
336     ** At this point, variables are initialized as follows:
337     **
338     **   flag_alternateform          TRUE if a '#' is present.
339     **   flag_plussign               TRUE if a '+' is present.
340     **   flag_leftjustify            TRUE if a '-' is present or if the
341     **                               field width was negative.
342     **   flag_zeropad                TRUE if the width began with 0.
343     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
344     **                               the conversion character.
345     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
346     **                               the conversion character.
347     **   flag_blanksign              TRUE if a ' ' is present.
348     **   width                       The specified field width.  This is
349     **                               always non-negative.  Zero is the default.
350     **   precision                   The specified precision.  The default
351     **                               is -1.
352     **   xtype                       The class of the conversion.
353     **   infop                       Pointer to the appropriate info struct.
354     */
355     switch( xtype ){
356       case etPOINTER:
357         flag_longlong = sizeof(char*)==sizeof(i64);
358         flag_long = sizeof(char*)==sizeof(long int);
359         /* Fall through into the next case */
360       case etRADIX:
361         if( infop->flags & FLAG_SIGNED ){
362           i64 v;
363           if( flag_longlong )   v = va_arg(ap,i64);
364           else if( flag_long )  v = va_arg(ap,long int);
365           else                  v = va_arg(ap,int);
366           if( v<0 ){
367             longvalue = -v;
368             prefix = '-';
369           }else{
370             longvalue = v;
371             if( flag_plussign )        prefix = '+';
372             else if( flag_blanksign )  prefix = ' ';
373             else                       prefix = 0;
374           }
375         }else{
376           if( flag_longlong )   longvalue = va_arg(ap,u64);
377           else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
378           else                  longvalue = va_arg(ap,unsigned int);
379           prefix = 0;
380         }
381         if( longvalue==0 ) flag_alternateform = 0;
382         if( flag_zeropad && precision<width-(prefix!=0) ){
383           precision = width-(prefix!=0);
384         }
385         bufpt = &buf[etBUFSIZE-1];
386         {
387           register const char *cset;      /* Use registers for speed */
388           register int base;
389           cset = &aDigits[infop->charset];
390           base = infop->base;
391           do{                                           /* Convert to ascii */
392             *(--bufpt) = cset[longvalue%base];
393             longvalue = longvalue/base;
394           }while( longvalue>0 );
395         }
396         length = &buf[etBUFSIZE-1]-bufpt;
397         for(idx=precision-length; idx>0; idx--){
398           *(--bufpt) = '0';                             /* Zero pad */
399         }
400         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
401         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
402           const char *pre;
403           char x;
404           pre = &aPrefix[infop->prefix];
405           if( *bufpt!=pre[0] ){
406             for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
407           }
408         }
409         length = &buf[etBUFSIZE-1]-bufpt;
410         break;
411       case etFLOAT:
412       case etEXP:
413       case etGENERIC:
414         realvalue = va_arg(ap,double);
415 #ifndef etNOFLOATINGPOINT
416         if( precision<0 ) precision = 6;         /* Set default precision */
417         if( precision>etBUFSIZE-10 ) precision = etBUFSIZE-10;
418         if( realvalue<0.0 ){
419           realvalue = -realvalue;
420           prefix = '-';
421         }else{
422           if( flag_plussign )          prefix = '+';
423           else if( flag_blanksign )    prefix = ' ';
424           else                         prefix = 0;
425         }
426         if( infop->type==etGENERIC && precision>0 ) precision--;
427         rounder = 0.0;
428 #if 0
429         /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
430         for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
431 #else
432         /* It makes more sense to use 0.5 */
433         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1);
434 #endif
435         if( infop->type==etFLOAT ) realvalue += rounder;
436         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
437         exp = 0;
438         if( realvalue>0.0 ){
439           while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
440           while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
441           while( realvalue<1e-8 && exp>=-350 ){ realvalue *= 1e8; exp-=8; }
442           while( realvalue<1.0 && exp>=-350 ){ realvalue *= 10.0; exp--; }
443           if( exp>350 || exp<-350 ){
444             bufpt = "NaN";
445             length = 3;
446             break;
447           }
448         }
449         bufpt = buf;
450         /*
451         ** If the field type is etGENERIC, then convert to either etEXP
452         ** or etFLOAT, as appropriate.
453         */
454         flag_exp = xtype==etEXP;
455         if( xtype!=etFLOAT ){
456           realvalue += rounder;
457           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
458         }
459         if( xtype==etGENERIC ){
460           flag_rtz = !flag_alternateform;
461           if( exp<-4 || exp>precision ){
462             xtype = etEXP;
463           }else{
464             precision = precision - exp;
465             xtype = etFLOAT;
466           }
467         }else{
468           flag_rtz = 0;
469         }
470         /*
471         ** The "exp+precision" test causes output to be of type etEXP if
472         ** the precision is too large to fit in buf[].
473         */
474         nsd = 0;
475         if( xtype==etFLOAT && exp+precision<etBUFSIZE-30 ){
476           flag_dp = (precision>0 || flag_alternateform);
477           if( prefix ) *(bufpt++) = prefix;         /* Sign */
478           if( exp<0 )  *(bufpt++) = '0';            /* Digits before "." */
479           else for(; exp>=0; exp--) *(bufpt++) = et_getdigit(&realvalue,&nsd);
480           if( flag_dp ) *(bufpt++) = '.';           /* The decimal point */
481           for(exp++; exp<0 && precision>0; precision--, exp++){
482             *(bufpt++) = '0';
483           }
484           while( (precision--)>0 ) *(bufpt++) = et_getdigit(&realvalue,&nsd);
485           *(bufpt--) = 0;                           /* Null terminate */
486           if( flag_rtz && flag_dp ){     /* Remove trailing zeros and "." */
487             while( bufpt>=buf && *bufpt=='0' ) *(bufpt--) = 0;
488             if( bufpt>=buf && *bufpt=='.' ) *(bufpt--) = 0;
489           }
490           bufpt++;                            /* point to next free slot */
491         }else{    /* etEXP or etGENERIC */
492           flag_dp = (precision>0 || flag_alternateform);
493           if( prefix ) *(bufpt++) = prefix;   /* Sign */
494           *(bufpt++) = et_getdigit(&realvalue,&nsd);  /* First digit */
495           if( flag_dp ) *(bufpt++) = '.';     /* Decimal point */
496           while( (precision--)>0 ) *(bufpt++) = et_getdigit(&realvalue,&nsd);
497           bufpt--;                            /* point to last digit */
498           if( flag_rtz && flag_dp ){          /* Remove tail zeros */
499             while( bufpt>=buf && *bufpt=='0' ) *(bufpt--) = 0;
500             if( bufpt>=buf && *bufpt=='.' ) *(bufpt--) = 0;
501           }
502           bufpt++;                            /* point to next free slot */
503           if( exp || flag_exp ){
504             *(bufpt++) = aDigits[infop->charset];
505             if( exp<0 ){ *(bufpt++) = '-'; exp = -exp; } /* sign of exp */
506             else       { *(bufpt++) = '+'; }
507             if( exp>=100 ){
508               *(bufpt++) = (exp/100)+'0';                /* 100's digit */
509               exp %= 100;
510             }
511             *(bufpt++) = exp/10+'0';                     /* 10's digit */
512             *(bufpt++) = exp%10+'0';                     /* 1's digit */
513           }
514         }
515         /* The converted number is in buf[] and zero terminated. Output it.
516         ** Note that the number is in the usual order, not reversed as with
517         ** integer conversions. */
518         length = bufpt-buf;
519         bufpt = buf;
520 
521         /* Special case:  Add leading zeros if the flag_zeropad flag is
522         ** set and we are not left justified */
523         if( flag_zeropad && !flag_leftjustify && length < width){
524           int i;
525           int nPad = width - length;
526           for(i=width; i>=nPad; i--){
527             bufpt[i] = bufpt[i-nPad];
528           }
529           i = prefix!=0;
530           while( nPad-- ) bufpt[i++] = '0';
531           length = width;
532         }
533 #endif
534         break;
535       case etSIZE:
536         *(va_arg(ap,int*)) = count;
537         length = width = 0;
538         break;
539       case etPERCENT:
540         buf[0] = '%';
541         bufpt = buf;
542         length = 1;
543         break;
544       case etCHARLIT:
545       case etCHARX:
546         c = buf[0] = (xtype==etCHARX ? va_arg(ap,int) : *++fmt);
547         if( precision>=0 ){
548           for(idx=1; idx<precision; idx++) buf[idx] = c;
549           length = precision;
550         }else{
551           length =1;
552         }
553         bufpt = buf;
554         break;
555       case etSTRING:
556       case etDYNSTRING:
557         bufpt = va_arg(ap,char*);
558         if( bufpt==0 ){
559           bufpt = "";
560         }else if( xtype==etDYNSTRING ){
561           zExtra = bufpt;
562         }
563         length = strlen(bufpt);
564         if( precision>=0 && precision<length ) length = precision;
565         break;
566       case etSQLESCAPE:
567       case etSQLESCAPE2:
568         {
569           int i, j, n, c, isnull;
570           int needQuote;
571           char *arg = va_arg(ap,char*);
572           isnull = arg==0;
573           if( isnull ) arg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
574           for(i=n=0; (c=arg[i])!=0; i++){
575             if( c=='\'' )  n++;
576           }
577           needQuote = !isnull && xtype==etSQLESCAPE2;
578           n += i + 1 + needQuote*2;
579           if( n>etBUFSIZE ){
580             bufpt = zExtra = sqliteMalloc( n );
581             if( bufpt==0 ) return -1;
582           }else{
583             bufpt = buf;
584           }
585           j = 0;
586           if( needQuote ) bufpt[j++] = '\'';
587           for(i=0; (c=arg[i])!=0; i++){
588             bufpt[j++] = c;
589             if( c=='\'' ) bufpt[j++] = c;
590           }
591           if( needQuote ) bufpt[j++] = '\'';
592           bufpt[j] = 0;
593           length = j;
594           if( precision>=0 && precision<length ) length = precision;
595         }
596         break;
597       case etTOKEN: {
598         Token *pToken = va_arg(ap, Token*);
599         if( pToken && pToken->z ){
600           (*func)(arg, pToken->z, pToken->n);
601         }
602         length = width = 0;
603         break;
604       }
605       case etSRCLIST: {
606         SrcList *pSrc = va_arg(ap, SrcList*);
607         int k = va_arg(ap, int);
608         struct SrcList_item *pItem = &pSrc->a[k];
609         assert( k>=0 && k<pSrc->nSrc );
610         if( pItem->zDatabase && pItem->zDatabase[0] ){
611           (*func)(arg, pItem->zDatabase, strlen(pItem->zDatabase));
612           (*func)(arg, ".", 1);
613         }
614         (*func)(arg, pItem->zName, strlen(pItem->zName));
615         length = width = 0;
616         break;
617       }
618       case etERROR:
619         buf[0] = '%';
620         buf[1] = c;
621         errorflag = 0;
622         idx = 1+(c!=0);
623         (*func)(arg,"%",idx);
624         count += idx;
625         if( c==0 ) fmt--;
626         break;
627     }/* End switch over the format type */
628     /*
629     ** The text of the conversion is pointed to by "bufpt" and is
630     ** "length" characters long.  The field width is "width".  Do
631     ** the output.
632     */
633     if( !flag_leftjustify ){
634       register int nspace;
635       nspace = width-length;
636       if( nspace>0 ){
637         count += nspace;
638         while( nspace>=etSPACESIZE ){
639           (*func)(arg,spaces,etSPACESIZE);
640           nspace -= etSPACESIZE;
641         }
642         if( nspace>0 ) (*func)(arg,spaces,nspace);
643       }
644     }
645     if( length>0 ){
646       (*func)(arg,bufpt,length);
647       count += length;
648     }
649     if( flag_leftjustify ){
650       register int nspace;
651       nspace = width-length;
652       if( nspace>0 ){
653         count += nspace;
654         while( nspace>=etSPACESIZE ){
655           (*func)(arg,spaces,etSPACESIZE);
656           nspace -= etSPACESIZE;
657         }
658         if( nspace>0 ) (*func)(arg,spaces,nspace);
659       }
660     }
661     if( zExtra ){
662       sqliteFree(zExtra);
663     }
664   }/* End for loop over the format string */
665   return errorflag ? -1 : count;
666 } /* End of function */
667 
668 
669 /* This structure is used to store state information about the
670 ** write to memory that is currently in progress.
671 */
672 struct sgMprintf {
673   char *zBase;     /* A base allocation */
674   char *zText;     /* The string collected so far */
675   int  nChar;      /* Length of the string so far */
676   int  nTotal;     /* Output size if unconstrained */
677   int  nAlloc;     /* Amount of space allocated in zText */
678   void *(*xRealloc)(void*,int);  /* Function used to realloc memory */
679 };
680 
681 /*
682 ** This function implements the callback from vxprintf.
683 **
684 ** This routine add nNewChar characters of text in zNewText to
685 ** the sgMprintf structure pointed to by "arg".
686 */
687 static void mout(void *arg, const char *zNewText, int nNewChar){
688   struct sgMprintf *pM = (struct sgMprintf*)arg;
689   pM->nTotal += nNewChar;
690   if( pM->nChar + nNewChar + 1 > pM->nAlloc ){
691     if( pM->xRealloc==0 ){
692       nNewChar =  pM->nAlloc - pM->nChar - 1;
693     }else{
694       pM->nAlloc = pM->nChar + nNewChar*2 + 1;
695       if( pM->zText==pM->zBase ){
696         pM->zText = pM->xRealloc(0, pM->nAlloc);
697         if( pM->zText && pM->nChar ){
698           memcpy(pM->zText, pM->zBase, pM->nChar);
699         }
700       }else{
701         pM->zText = pM->xRealloc(pM->zText, pM->nAlloc);
702       }
703     }
704   }
705   if( pM->zText ){
706     if( nNewChar>0 ){
707       memcpy(&pM->zText[pM->nChar], zNewText, nNewChar);
708       pM->nChar += nNewChar;
709     }
710     pM->zText[pM->nChar] = 0;
711   }
712 }
713 
714 /*
715 ** This routine is a wrapper around xprintf() that invokes mout() as
716 ** the consumer.
717 */
718 static char *base_vprintf(
719   void *(*xRealloc)(void*,int),   /* Routine to realloc memory. May be NULL */
720   int useInternal,                /* Use internal %-conversions if true */
721   char *zInitBuf,                 /* Initially write here, before mallocing */
722   int nInitBuf,                   /* Size of zInitBuf[] */
723   const char *zFormat,            /* format string */
724   va_list ap                      /* arguments */
725 ){
726   struct sgMprintf sM;
727   sM.zBase = sM.zText = zInitBuf;
728   sM.nChar = sM.nTotal = 0;
729   sM.nAlloc = nInitBuf;
730   sM.xRealloc = xRealloc;
731   vxprintf(mout, &sM, useInternal, zFormat, ap);
732   if( xRealloc ){
733     if( sM.zText==sM.zBase ){
734       sM.zText = xRealloc(0, sM.nChar+1);
735       if( sM.zText ){
736         memcpy(sM.zText, sM.zBase, sM.nChar+1);
737       }
738     }else if( sM.nAlloc>sM.nChar+10 ){
739       sM.zText = xRealloc(sM.zText, sM.nChar+1);
740     }
741   }
742   return sM.zText;
743 }
744 
745 /*
746 ** Realloc that is a real function, not a macro.
747 */
748 static void *printf_realloc(void *old, int size){
749   return sqliteRealloc(old,size);
750 }
751 
752 /*
753 ** Print into memory obtained from sqliteMalloc().  Use the internal
754 ** %-conversion extensions.
755 */
756 char *sqlite3VMPrintf(const char *zFormat, va_list ap){
757   char zBase[1000];
758   return base_vprintf(printf_realloc, 1, zBase, sizeof(zBase), zFormat, ap);
759 }
760 
761 /*
762 ** Print into memory obtained from sqliteMalloc().  Use the internal
763 ** %-conversion extensions.
764 */
765 char *sqlite3MPrintf(const char *zFormat, ...){
766   va_list ap;
767   char *z;
768   char zBase[1000];
769   va_start(ap, zFormat);
770   z = base_vprintf(printf_realloc, 1, zBase, sizeof(zBase), zFormat, ap);
771   va_end(ap);
772   return z;
773 }
774 
775 /*
776 ** Print into memory obtained from malloc().  Do not use the internal
777 ** %-conversion extensions.  This routine is for use by external users.
778 */
779 char *sqlite3_mprintf(const char *zFormat, ...){
780   va_list ap;
781   char *z;
782   char zBuf[200];
783 
784   va_start(ap,zFormat);
785   z = base_vprintf((void*(*)(void*,int))realloc, 0,
786                    zBuf, sizeof(zBuf), zFormat, ap);
787   va_end(ap);
788   return z;
789 }
790 
791 /* This is the varargs version of sqlite3_mprintf.
792 */
793 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
794   char zBuf[200];
795   return base_vprintf((void*(*)(void*,int))realloc, 0,
796                       zBuf, sizeof(zBuf), zFormat, ap);
797 }
798 
799 /*
800 ** sqlite3_snprintf() works like snprintf() except that it ignores the
801 ** current locale settings.  This is important for SQLite because we
802 ** are not able to use a "," as the decimal point in place of "." as
803 ** specified by some locales.
804 */
805 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
806   char *z;
807   va_list ap;
808 
809   va_start(ap,zFormat);
810   z = base_vprintf(0, 0, zBuf, n, zFormat, ap);
811   va_end(ap);
812   return z;
813 }
814 
815 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
816 /*
817 ** A version of printf() that understands %lld.  Used for debugging.
818 ** The printf() built into some versions of windows does not understand %lld
819 ** and segfaults if you give it a long long int.
820 */
821 void sqlite3DebugPrintf(const char *zFormat, ...){
822   extern int getpid(void);
823   va_list ap;
824   char zBuf[500];
825   va_start(ap, zFormat);
826   base_vprintf(0, 0, zBuf, sizeof(zBuf), zFormat, ap);
827   va_end(ap);
828   fprintf(stdout,"%d: %s", getpid(), zBuf);
829   fflush(stdout);
830 }
831 #endif
832