xref: /sqlite-3.40.0/src/printf.c (revision 74217cc0)
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  They are very out-of-date but might be useful as
5 ** an historical reference.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   {  '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   {  'f',  0, 1, etFLOAT,      0,  0 },
124   {  'e',  0, 1, etEXP,        30, 0 },
125   {  'E',  0, 1, etEXP,        14, 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 /*
167 ** On machines with a small stack size, you can redefine the
168 ** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
169 ** smaller values some %f conversions may go into an infinite loop.
170 */
171 #ifndef SQLITE_PRINT_BUF_SIZE
172 # define SQLITE_PRINT_BUF_SIZE 350
173 #endif
174 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
175 
176 /*
177 ** The root program.  All variations call this core.
178 **
179 ** INPUTS:
180 **   func   This is a pointer to a function taking three arguments
181 **            1. A pointer to anything.  Same as the "arg" parameter.
182 **            2. A pointer to the list of characters to be output
183 **               (Note, this list is NOT null terminated.)
184 **            3. An integer number of characters to be output.
185 **               (Note: This number might be zero.)
186 **
187 **   arg    This is the pointer to anything which will be passed as the
188 **          first argument to "func".  Use it for whatever you like.
189 **
190 **   fmt    This is the format string, as in the usual print.
191 **
192 **   ap     This is a pointer to a list of arguments.  Same as in
193 **          vfprint.
194 **
195 ** OUTPUTS:
196 **          The return value is the total number of characters sent to
197 **          the function "func".  Returns -1 on a error.
198 **
199 ** Note that the order in which automatic variables are declared below
200 ** seems to make a big difference in determining how fast this beast
201 ** will run.
202 */
203 static int vxprintf(
204   void (*func)(void*,const char*,int),     /* Consumer of text */
205   void *arg,                         /* First argument to the consumer */
206   int useExtended,                   /* Allow extended %-conversions */
207   const char *fmt,                   /* Format string */
208   va_list ap                         /* arguments */
209 ){
210   int c;                     /* Next character in the format string */
211   char *bufpt;               /* Pointer to the conversion buffer */
212   int precision;             /* Precision of the current field */
213   int length;                /* Length of the field */
214   int idx;                   /* A general purpose loop counter */
215   int count;                 /* Total number of characters output */
216   int width;                 /* Width of the current field */
217   etByte flag_leftjustify;   /* True if "-" flag is present */
218   etByte flag_plussign;      /* True if "+" flag is present */
219   etByte flag_blanksign;     /* True if " " flag is present */
220   etByte flag_alternateform; /* True if "#" flag is present */
221   etByte flag_altform2;      /* True if "!" flag is present */
222   etByte flag_zeropad;       /* True if field width constant starts with zero */
223   etByte flag_long;          /* True if "l" flag is present */
224   etByte flag_longlong;      /* True if the "ll" flag is present */
225   etByte done;               /* Loop termination flag */
226   UINT64_TYPE longvalue;     /* Value for integer types */
227   LONGDOUBLE_TYPE realvalue; /* Value for real types */
228   const et_info *infop;      /* Pointer to the appropriate info structure */
229   char buf[etBUFSIZE];       /* Conversion buffer */
230   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
231   etByte errorflag = 0;      /* True if an error is encountered */
232   etByte xtype;              /* Conversion paradigm */
233   char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
234   static const char spaces[] =
235    "                                                                         ";
236 #define etSPACESIZE (sizeof(spaces)-1)
237 #ifndef etNOFLOATINGPOINT
238   int  exp, e2;              /* exponent of real numbers */
239   double rounder;            /* Used for rounding floating point values */
240   etByte flag_dp;            /* True if decimal point should be shown */
241   etByte flag_rtz;           /* True if trailing zeros should be removed */
242   etByte flag_exp;           /* True to force display of the exponent */
243   int nsd;                   /* Number of significant digits returned */
244 #endif
245 
246   func(arg,"",0);
247   count = length = 0;
248   bufpt = 0;
249   for(; (c=(*fmt))!=0; ++fmt){
250     if( c!='%' ){
251       int amt;
252       bufpt = (char *)fmt;
253       amt = 1;
254       while( (c=(*++fmt))!='%' && c!=0 ) amt++;
255       (*func)(arg,bufpt,amt);
256       count += amt;
257       if( c==0 ) break;
258     }
259     if( (c=(*++fmt))==0 ){
260       errorflag = 1;
261       (*func)(arg,"%",1);
262       count++;
263       break;
264     }
265     /* Find out what flags are present */
266     flag_leftjustify = flag_plussign = flag_blanksign =
267      flag_alternateform = flag_altform2 = flag_zeropad = 0;
268     done = 0;
269     do{
270       switch( c ){
271         case '-':   flag_leftjustify = 1;     break;
272         case '+':   flag_plussign = 1;        break;
273         case ' ':   flag_blanksign = 1;       break;
274         case '#':   flag_alternateform = 1;   break;
275         case '!':   flag_altform2 = 1;        break;
276         case '0':   flag_zeropad = 1;         break;
277         default:    done = 1;                 break;
278       }
279     }while( !done && (c=(*++fmt))!=0 );
280     /* Get the field width */
281     width = 0;
282     if( c=='*' ){
283       width = va_arg(ap,int);
284       if( width<0 ){
285         flag_leftjustify = 1;
286         width = -width;
287       }
288       c = *++fmt;
289     }else{
290       while( c>='0' && c<='9' ){
291         width = width*10 + c - '0';
292         c = *++fmt;
293       }
294     }
295     if( width > etBUFSIZE-10 ){
296       width = etBUFSIZE-10;
297     }
298     /* Get the precision */
299     if( c=='.' ){
300       precision = 0;
301       c = *++fmt;
302       if( c=='*' ){
303         precision = va_arg(ap,int);
304         if( precision<0 ) precision = -precision;
305         c = *++fmt;
306       }else{
307         while( c>='0' && c<='9' ){
308           precision = precision*10 + c - '0';
309           c = *++fmt;
310         }
311       }
312     }else{
313       precision = -1;
314     }
315     /* Get the conversion type modifier */
316     if( c=='l' ){
317       flag_long = 1;
318       c = *++fmt;
319       if( c=='l' ){
320         flag_longlong = 1;
321         c = *++fmt;
322       }else{
323         flag_longlong = 0;
324       }
325     }else{
326       flag_long = flag_longlong = 0;
327     }
328     /* Fetch the info entry for the field */
329     infop = 0;
330     xtype = etERROR;
331     for(idx=0; idx<etNINFO; idx++){
332       if( c==fmtinfo[idx].fmttype ){
333         infop = &fmtinfo[idx];
334         if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
335           xtype = infop->type;
336         }
337         break;
338       }
339     }
340     zExtra = 0;
341 
342     /* Limit the precision to prevent overflowing buf[] during conversion */
343     if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
344       precision = etBUFSIZE-40;
345     }
346 
347     /*
348     ** At this point, variables are initialized as follows:
349     **
350     **   flag_alternateform          TRUE if a '#' is present.
351     **   flag_altform2               TRUE if a '!' is present.
352     **   flag_plussign               TRUE if a '+' is present.
353     **   flag_leftjustify            TRUE if a '-' is present or if the
354     **                               field width was negative.
355     **   flag_zeropad                TRUE if the width began with 0.
356     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
357     **                               the conversion character.
358     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
359     **                               the conversion character.
360     **   flag_blanksign              TRUE if a ' ' is present.
361     **   width                       The specified field width.  This is
362     **                               always non-negative.  Zero is the default.
363     **   precision                   The specified precision.  The default
364     **                               is -1.
365     **   xtype                       The class of the conversion.
366     **   infop                       Pointer to the appropriate info struct.
367     */
368     switch( xtype ){
369       case etPOINTER:
370         flag_longlong = sizeof(char*)==sizeof(i64);
371         flag_long = sizeof(char*)==sizeof(long int);
372         /* Fall through into the next case */
373       case etRADIX:
374         if( infop->flags & FLAG_SIGNED ){
375           i64 v;
376           if( flag_longlong )   v = va_arg(ap,i64);
377           else if( flag_long )  v = va_arg(ap,long int);
378           else                  v = va_arg(ap,int);
379           if( v<0 ){
380             longvalue = -v;
381             prefix = '-';
382           }else{
383             longvalue = v;
384             if( flag_plussign )        prefix = '+';
385             else if( flag_blanksign )  prefix = ' ';
386             else                       prefix = 0;
387           }
388         }else{
389           if( flag_longlong )   longvalue = va_arg(ap,u64);
390           else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
391           else                  longvalue = va_arg(ap,unsigned int);
392           prefix = 0;
393         }
394         if( longvalue==0 ) flag_alternateform = 0;
395         if( flag_zeropad && precision<width-(prefix!=0) ){
396           precision = width-(prefix!=0);
397         }
398         bufpt = &buf[etBUFSIZE-1];
399         {
400           register const char *cset;      /* Use registers for speed */
401           register int base;
402           cset = &aDigits[infop->charset];
403           base = infop->base;
404           do{                                           /* Convert to ascii */
405             *(--bufpt) = cset[longvalue%base];
406             longvalue = longvalue/base;
407           }while( longvalue>0 );
408         }
409         length = &buf[etBUFSIZE-1]-bufpt;
410         for(idx=precision-length; idx>0; idx--){
411           *(--bufpt) = '0';                             /* Zero pad */
412         }
413         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
414         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
415           const char *pre;
416           char x;
417           pre = &aPrefix[infop->prefix];
418           if( *bufpt!=pre[0] ){
419             for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
420           }
421         }
422         length = &buf[etBUFSIZE-1]-bufpt;
423         break;
424       case etFLOAT:
425       case etEXP:
426       case etGENERIC:
427         realvalue = va_arg(ap,double);
428 #ifndef etNOFLOATINGPOINT
429         if( precision<0 ) precision = 6;         /* Set default precision */
430         if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
431         if( realvalue<0.0 ){
432           realvalue = -realvalue;
433           prefix = '-';
434         }else{
435           if( flag_plussign )          prefix = '+';
436           else if( flag_blanksign )    prefix = ' ';
437           else                         prefix = 0;
438         }
439         if( xtype==etGENERIC && precision>0 ) precision--;
440 #if 0
441         /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
442         for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
443 #else
444         /* It makes more sense to use 0.5 */
445         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1);
446 #endif
447         if( xtype==etFLOAT ) realvalue += rounder;
448         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
449         exp = 0;
450         if( realvalue>0.0 ){
451           while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
452           while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
453           while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
454           while( realvalue<1e-8 && exp>=-350 ){ realvalue *= 1e8; exp-=8; }
455           while( realvalue<1.0 && exp>=-350 ){ realvalue *= 10.0; exp--; }
456           if( exp>350 || exp<-350 ){
457             bufpt = "NaN";
458             length = 3;
459             break;
460           }
461         }
462         bufpt = buf;
463         /*
464         ** If the field type is etGENERIC, then convert to either etEXP
465         ** or etFLOAT, as appropriate.
466         */
467         flag_exp = xtype==etEXP;
468         if( xtype!=etFLOAT ){
469           realvalue += rounder;
470           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
471         }
472         if( xtype==etGENERIC ){
473           flag_rtz = !flag_alternateform;
474           if( exp<-4 || exp>precision ){
475             xtype = etEXP;
476           }else{
477             precision = precision - exp;
478             xtype = etFLOAT;
479           }
480         }else{
481           flag_rtz = 0;
482         }
483         if( xtype==etEXP ){
484           e2 = 0;
485         }else{
486           e2 = exp;
487         }
488         nsd = 0;
489         flag_dp = (precision>0) | flag_alternateform | flag_altform2;
490         /* The sign in front of the number */
491         if( prefix ){
492           *(bufpt++) = prefix;
493         }
494         /* Digits prior to the decimal point */
495         if( e2<0 ){
496           *(bufpt++) = '0';
497         }else{
498           for(; e2>=0; e2--){
499             *(bufpt++) = et_getdigit(&realvalue,&nsd);
500           }
501         }
502         /* The decimal point */
503         if( flag_dp ){
504           *(bufpt++) = '.';
505         }
506         /* "0" digits after the decimal point but before the first
507         ** significant digit of the number */
508         for(e2++; e2<0 && precision>0; precision--, e2++){
509           *(bufpt++) = '0';
510         }
511         /* Significant digits after the decimal point */
512         while( (precision--)>0 ){
513           *(bufpt++) = et_getdigit(&realvalue,&nsd);
514         }
515         /* Remove trailing zeros and the "." if no digits follow the "." */
516         if( flag_rtz && flag_dp ){
517           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
518           assert( bufpt>buf );
519           if( bufpt[-1]=='.' ){
520             if( flag_altform2 ){
521               *(bufpt++) = '0';
522             }else{
523               *(--bufpt) = 0;
524             }
525           }
526         }
527         /* Add the "eNNN" suffix */
528         if( flag_exp || (xtype==etEXP && exp) ){
529           *(bufpt++) = aDigits[infop->charset];
530           if( exp<0 ){
531             *(bufpt++) = '-'; exp = -exp;
532           }else{
533             *(bufpt++) = '+';
534           }
535           if( exp>=100 ){
536             *(bufpt++) = (exp/100)+'0';                /* 100's digit */
537             exp %= 100;
538           }
539           *(bufpt++) = exp/10+'0';                     /* 10's digit */
540           *(bufpt++) = exp%10+'0';                     /* 1's digit */
541         }
542         *bufpt = 0;
543 
544         /* The converted number is in buf[] and zero terminated. Output it.
545         ** Note that the number is in the usual order, not reversed as with
546         ** integer conversions. */
547         length = bufpt-buf;
548         bufpt = buf;
549 
550         /* Special case:  Add leading zeros if the flag_zeropad flag is
551         ** set and we are not left justified */
552         if( flag_zeropad && !flag_leftjustify && length < width){
553           int i;
554           int nPad = width - length;
555           for(i=width; i>=nPad; i--){
556             bufpt[i] = bufpt[i-nPad];
557           }
558           i = prefix!=0;
559           while( nPad-- ) bufpt[i++] = '0';
560           length = width;
561         }
562 #endif
563         break;
564       case etSIZE:
565         *(va_arg(ap,int*)) = count;
566         length = width = 0;
567         break;
568       case etPERCENT:
569         buf[0] = '%';
570         bufpt = buf;
571         length = 1;
572         break;
573       case etCHARLIT:
574       case etCHARX:
575         c = buf[0] = (xtype==etCHARX ? va_arg(ap,int) : *++fmt);
576         if( precision>=0 ){
577           for(idx=1; idx<precision; idx++) buf[idx] = c;
578           length = precision;
579         }else{
580           length =1;
581         }
582         bufpt = buf;
583         break;
584       case etSTRING:
585       case etDYNSTRING:
586         bufpt = va_arg(ap,char*);
587         if( bufpt==0 ){
588           bufpt = "";
589         }else if( xtype==etDYNSTRING ){
590           zExtra = bufpt;
591         }
592         length = strlen(bufpt);
593         if( precision>=0 && precision<length ) length = precision;
594         break;
595       case etSQLESCAPE:
596       case etSQLESCAPE2: {
597         int i, j, n, c, isnull;
598         int needQuote;
599         char *arg = va_arg(ap,char*);
600         isnull = arg==0;
601         if( isnull ) arg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
602         for(i=n=0; (c=arg[i])!=0; i++){
603           if( c=='\'' )  n++;
604         }
605         needQuote = !isnull && xtype==etSQLESCAPE2;
606         n += i + 1 + needQuote*2;
607         if( n>etBUFSIZE ){
608           bufpt = zExtra = sqliteMalloc( n );
609           if( bufpt==0 ) return -1;
610         }else{
611           bufpt = buf;
612         }
613         j = 0;
614         if( needQuote ) bufpt[j++] = '\'';
615         for(i=0; (c=arg[i])!=0; i++){
616           bufpt[j++] = c;
617           if( c=='\'' ) bufpt[j++] = c;
618         }
619         if( needQuote ) bufpt[j++] = '\'';
620         bufpt[j] = 0;
621         length = j;
622         if( precision>=0 && precision<length ) length = precision;
623         break;
624       }
625       case etTOKEN: {
626         Token *pToken = va_arg(ap, Token*);
627         if( pToken && pToken->z ){
628           (*func)(arg, pToken->z, pToken->n);
629         }
630         length = width = 0;
631         break;
632       }
633       case etSRCLIST: {
634         SrcList *pSrc = va_arg(ap, SrcList*);
635         int k = va_arg(ap, int);
636         struct SrcList_item *pItem = &pSrc->a[k];
637         assert( k>=0 && k<pSrc->nSrc );
638         if( pItem->zDatabase && pItem->zDatabase[0] ){
639           (*func)(arg, pItem->zDatabase, strlen(pItem->zDatabase));
640           (*func)(arg, ".", 1);
641         }
642         (*func)(arg, pItem->zName, strlen(pItem->zName));
643         length = width = 0;
644         break;
645       }
646       case etERROR:
647         buf[0] = '%';
648         buf[1] = c;
649         errorflag = 0;
650         idx = 1+(c!=0);
651         (*func)(arg,"%",idx);
652         count += idx;
653         if( c==0 ) fmt--;
654         break;
655     }/* End switch over the format type */
656     /*
657     ** The text of the conversion is pointed to by "bufpt" and is
658     ** "length" characters long.  The field width is "width".  Do
659     ** the output.
660     */
661     if( !flag_leftjustify ){
662       register int nspace;
663       nspace = width-length;
664       if( nspace>0 ){
665         count += nspace;
666         while( nspace>=etSPACESIZE ){
667           (*func)(arg,spaces,etSPACESIZE);
668           nspace -= etSPACESIZE;
669         }
670         if( nspace>0 ) (*func)(arg,spaces,nspace);
671       }
672     }
673     if( length>0 ){
674       (*func)(arg,bufpt,length);
675       count += length;
676     }
677     if( flag_leftjustify ){
678       register int nspace;
679       nspace = width-length;
680       if( nspace>0 ){
681         count += nspace;
682         while( nspace>=etSPACESIZE ){
683           (*func)(arg,spaces,etSPACESIZE);
684           nspace -= etSPACESIZE;
685         }
686         if( nspace>0 ) (*func)(arg,spaces,nspace);
687       }
688     }
689     if( zExtra ){
690       sqliteFree(zExtra);
691     }
692   }/* End for loop over the format string */
693   return errorflag ? -1 : count;
694 } /* End of function */
695 
696 
697 /* This structure is used to store state information about the
698 ** write to memory that is currently in progress.
699 */
700 struct sgMprintf {
701   char *zBase;     /* A base allocation */
702   char *zText;     /* The string collected so far */
703   int  nChar;      /* Length of the string so far */
704   int  nTotal;     /* Output size if unconstrained */
705   int  nAlloc;     /* Amount of space allocated in zText */
706   void *(*xRealloc)(void*,int);  /* Function used to realloc memory */
707 };
708 
709 /*
710 ** This function implements the callback from vxprintf.
711 **
712 ** This routine add nNewChar characters of text in zNewText to
713 ** the sgMprintf structure pointed to by "arg".
714 */
715 static void mout(void *arg, const char *zNewText, int nNewChar){
716   struct sgMprintf *pM = (struct sgMprintf*)arg;
717   pM->nTotal += nNewChar;
718   if( pM->nChar + nNewChar + 1 > pM->nAlloc ){
719     if( pM->xRealloc==0 ){
720       nNewChar =  pM->nAlloc - pM->nChar - 1;
721     }else{
722       pM->nAlloc = pM->nChar + nNewChar*2 + 1;
723       if( pM->zText==pM->zBase ){
724         pM->zText = pM->xRealloc(0, pM->nAlloc);
725         if( pM->zText && pM->nChar ){
726           memcpy(pM->zText, pM->zBase, pM->nChar);
727         }
728       }else{
729         char *zNew;
730         zNew = pM->xRealloc(pM->zText, pM->nAlloc);
731         if( zNew ){
732           pM->zText = zNew;
733         }
734       }
735     }
736   }
737   if( pM->zText ){
738     if( nNewChar>0 ){
739       memcpy(&pM->zText[pM->nChar], zNewText, nNewChar);
740       pM->nChar += nNewChar;
741     }
742     pM->zText[pM->nChar] = 0;
743   }
744 }
745 
746 /*
747 ** This routine is a wrapper around xprintf() that invokes mout() as
748 ** the consumer.
749 */
750 static char *base_vprintf(
751   void *(*xRealloc)(void*,int),   /* Routine to realloc memory. May be NULL */
752   int useInternal,                /* Use internal %-conversions if true */
753   char *zInitBuf,                 /* Initially write here, before mallocing */
754   int nInitBuf,                   /* Size of zInitBuf[] */
755   const char *zFormat,            /* format string */
756   va_list ap                      /* arguments */
757 ){
758   struct sgMprintf sM;
759   sM.zBase = sM.zText = zInitBuf;
760   sM.nChar = sM.nTotal = 0;
761   sM.nAlloc = nInitBuf;
762   sM.xRealloc = xRealloc;
763   vxprintf(mout, &sM, useInternal, zFormat, ap);
764   if( xRealloc ){
765     if( sM.zText==sM.zBase ){
766       sM.zText = xRealloc(0, sM.nChar+1);
767       if( sM.zText ){
768         memcpy(sM.zText, sM.zBase, sM.nChar+1);
769       }
770     }else if( sM.nAlloc>sM.nChar+10 ){
771       char *zNew = xRealloc(sM.zText, sM.nChar+1);
772       if( zNew ){
773         sM.zText = zNew;
774       }
775     }
776   }
777   return sM.zText;
778 }
779 
780 /*
781 ** Realloc that is a real function, not a macro.
782 */
783 static void *printf_realloc(void *old, int size){
784   return sqliteRealloc(old,size);
785 }
786 
787 /*
788 ** Print into memory obtained from sqliteMalloc().  Use the internal
789 ** %-conversion extensions.
790 */
791 char *sqlite3VMPrintf(const char *zFormat, va_list ap){
792   char zBase[SQLITE_PRINT_BUF_SIZE];
793   return base_vprintf(printf_realloc, 1, zBase, sizeof(zBase), zFormat, ap);
794 }
795 
796 /*
797 ** Print into memory obtained from sqliteMalloc().  Use the internal
798 ** %-conversion extensions.
799 */
800 char *sqlite3MPrintf(const char *zFormat, ...){
801   va_list ap;
802   char *z;
803   char zBase[SQLITE_PRINT_BUF_SIZE];
804   va_start(ap, zFormat);
805   z = base_vprintf(printf_realloc, 1, zBase, sizeof(zBase), zFormat, ap);
806   va_end(ap);
807   return z;
808 }
809 
810 /*
811 ** Print into memory obtained from malloc().  Do not use the internal
812 ** %-conversion extensions.  This routine is for use by external users.
813 */
814 char *sqlite3_mprintf(const char *zFormat, ...){
815   va_list ap;
816   char *z;
817   char zBuf[200];
818 
819   va_start(ap,zFormat);
820   z = base_vprintf((void*(*)(void*,int))realloc, 0,
821                    zBuf, sizeof(zBuf), zFormat, ap);
822   va_end(ap);
823   return z;
824 }
825 
826 /* This is the varargs version of sqlite3_mprintf.
827 */
828 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
829   char zBuf[200];
830   return base_vprintf((void*(*)(void*,int))realloc, 0,
831                       zBuf, sizeof(zBuf), zFormat, ap);
832 }
833 
834 /*
835 ** sqlite3_snprintf() works like snprintf() except that it ignores the
836 ** current locale settings.  This is important for SQLite because we
837 ** are not able to use a "," as the decimal point in place of "." as
838 ** specified by some locales.
839 */
840 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
841   char *z;
842   va_list ap;
843 
844   va_start(ap,zFormat);
845   z = base_vprintf(0, 0, zBuf, n, zFormat, ap);
846   va_end(ap);
847   return z;
848 }
849 
850 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
851 /*
852 ** A version of printf() that understands %lld.  Used for debugging.
853 ** The printf() built into some versions of windows does not understand %lld
854 ** and segfaults if you give it a long long int.
855 */
856 void sqlite3DebugPrintf(const char *zFormat, ...){
857   extern int getpid(void);
858   va_list ap;
859   char zBuf[500];
860   va_start(ap, zFormat);
861   base_vprintf(0, 0, zBuf, sizeof(zBuf), zFormat, ap);
862   va_end(ap);
863   fprintf(stdout,"%d: %s", getpid(), zBuf);
864   fflush(stdout);
865 }
866 #endif
867