xref: /sqlite-3.40.0/src/printf.c (revision 4249b3f5)
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  They are very out-of-date but might be useful as
5 ** an historical reference.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 ** $Id: printf.c,v 1.92 2008/07/15 00:27:35 drh Exp $
9 **
10 **************************************************************************
11 **
12 ** The following modules is an enhanced replacement for the "printf" subroutines
13 ** found in the standard C library.  The following enhancements are
14 ** supported:
15 **
16 **      +  Additional functions.  The standard set of "printf" functions
17 **         includes printf, fprintf, sprintf, vprintf, vfprintf, and
18 **         vsprintf.  This module adds the following:
19 **
20 **           *  snprintf -- Works like sprintf, but has an extra argument
21 **                          which is the size of the buffer written to.
22 **
23 **           *  mprintf --  Similar to sprintf.  Writes output to memory
24 **                          obtained from malloc.
25 **
26 **           *  xprintf --  Calls a function to dispose of output.
27 **
28 **           *  nprintf --  No output, but returns the number of characters
29 **                          that would have been output by printf.
30 **
31 **           *  A v- version (ex: vsnprintf) of every function is also
32 **              supplied.
33 **
34 **      +  A few extensions to the formatting notation are supported:
35 **
36 **           *  The "=" flag (similar to "-") causes the output to be
37 **              be centered in the appropriately sized field.
38 **
39 **           *  The %b field outputs an integer in binary notation.
40 **
41 **           *  The %c field now accepts a precision.  The character output
42 **              is repeated by the number of times the precision specifies.
43 **
44 **           *  The %' field works like %c, but takes as its character the
45 **              next character of the format string, instead of the next
46 **              argument.  For example,  printf("%.78'-")  prints 78 minus
47 **              signs, the same as  printf("%.78c",'-').
48 **
49 **      +  When compiled using GCC on a SPARC, this version of printf is
50 **         faster than the library printf for SUN OS 4.1.
51 **
52 **      +  All functions are fully reentrant.
53 **
54 */
55 #include "sqliteInt.h"
56 
57 /*
58 ** Conversion types fall into various categories as defined by the
59 ** following enumeration.
60 */
61 #define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
62 #define etFLOAT       2 /* Floating point.  %f */
63 #define etEXP         3 /* Exponentional notation. %e and %E */
64 #define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
65 #define etSIZE        5 /* Return number of characters processed so far. %n */
66 #define etSTRING      6 /* Strings. %s */
67 #define etDYNSTRING   7 /* Dynamically allocated strings. %z */
68 #define etPERCENT     8 /* Percent symbol. %% */
69 #define etCHARX       9 /* Characters. %c */
70 /* The rest are extensions, not normally found in printf() */
71 #define etSQLESCAPE  10 /* Strings with '\'' doubled.  %q */
72 #define etSQLESCAPE2 11 /* Strings with '\'' doubled and enclosed in '',
73                           NULL pointers replaced by SQL NULL.  %Q */
74 #define etTOKEN      12 /* a pointer to a Token structure */
75 #define etSRCLIST    13 /* a pointer to a SrcList */
76 #define etPOINTER    14 /* The %p conversion */
77 #define etSQLESCAPE3 15 /* %w -> Strings with '\"' doubled */
78 #define etORDINAL    16 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
79 
80 
81 /*
82 ** An "etByte" is an 8-bit unsigned value.
83 */
84 typedef unsigned char etByte;
85 
86 /*
87 ** Each builtin conversion character (ex: the 'd' in "%d") is described
88 ** by an instance of the following structure
89 */
90 typedef struct et_info {   /* Information about each format field */
91   char fmttype;            /* The format field code letter */
92   etByte base;             /* The base for radix conversion */
93   etByte flags;            /* One or more of FLAG_ constants below */
94   etByte type;             /* Conversion paradigm */
95   etByte charset;          /* Offset into aDigits[] of the digits string */
96   etByte prefix;           /* Offset into aPrefix[] of the prefix string */
97 } et_info;
98 
99 /*
100 ** Allowed values for et_info.flags
101 */
102 #define FLAG_SIGNED  1     /* True if the value to convert is signed */
103 #define FLAG_INTERN  2     /* True if for internal use only */
104 #define FLAG_STRING  4     /* Allow infinity precision */
105 
106 
107 /*
108 ** The following table is searched linearly, so it is good to put the
109 ** most frequently used conversion types first.
110 */
111 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
112 static const char aPrefix[] = "-x0\000X0";
113 static const et_info fmtinfo[] = {
114   {  'd', 10, 1, etRADIX,      0,  0 },
115   {  's',  0, 4, etSTRING,     0,  0 },
116   {  'g',  0, 1, etGENERIC,    30, 0 },
117   {  'z',  0, 4, etDYNSTRING,  0,  0 },
118   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
119   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
120   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
121   {  'c',  0, 0, etCHARX,      0,  0 },
122   {  'o',  8, 0, etRADIX,      0,  2 },
123   {  'u', 10, 0, etRADIX,      0,  0 },
124   {  'x', 16, 0, etRADIX,      16, 1 },
125   {  'X', 16, 0, etRADIX,      0,  4 },
126 #ifndef SQLITE_OMIT_FLOATING_POINT
127   {  'f',  0, 1, etFLOAT,      0,  0 },
128   {  'e',  0, 1, etEXP,        30, 0 },
129   {  'E',  0, 1, etEXP,        14, 0 },
130   {  'G',  0, 1, etGENERIC,    14, 0 },
131 #endif
132   {  'i', 10, 1, etRADIX,      0,  0 },
133   {  'n',  0, 0, etSIZE,       0,  0 },
134   {  '%',  0, 0, etPERCENT,    0,  0 },
135   {  'p', 16, 0, etPOINTER,    0,  1 },
136   {  'T',  0, 2, etTOKEN,      0,  0 },
137   {  'S',  0, 2, etSRCLIST,    0,  0 },
138   {  'r', 10, 3, etORDINAL,    0,  0 },
139 };
140 #define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))
141 
142 /*
143 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
144 ** conversions will work.
145 */
146 #ifndef SQLITE_OMIT_FLOATING_POINT
147 /*
148 ** "*val" is a double such that 0.1 <= *val < 10.0
149 ** Return the ascii code for the leading digit of *val, then
150 ** multiply "*val" by 10.0 to renormalize.
151 **
152 ** Example:
153 **     input:     *val = 3.14159
154 **     output:    *val = 1.4159    function return = '3'
155 **
156 ** The counter *cnt is incremented each time.  After counter exceeds
157 ** 16 (the number of significant digits in a 64-bit float) '0' is
158 ** always returned.
159 */
160 static int et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
161   int digit;
162   LONGDOUBLE_TYPE d;
163   if( (*cnt)++ >= 16 ) return '0';
164   digit = (int)*val;
165   d = digit;
166   digit += '0';
167   *val = (*val - d)*10.0;
168   return digit;
169 }
170 #endif /* SQLITE_OMIT_FLOATING_POINT */
171 
172 /*
173 ** Append N space characters to the given string buffer.
174 */
175 static void appendSpace(StrAccum *pAccum, int N){
176   static const char zSpaces[] = "                             ";
177   while( N>=sizeof(zSpaces)-1 ){
178     sqlite3StrAccumAppend(pAccum, zSpaces, sizeof(zSpaces)-1);
179     N -= sizeof(zSpaces)-1;
180   }
181   if( N>0 ){
182     sqlite3StrAccumAppend(pAccum, zSpaces, N);
183   }
184 }
185 
186 /*
187 ** On machines with a small stack size, you can redefine the
188 ** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
189 ** smaller values some %f conversions may go into an infinite loop.
190 */
191 #ifndef SQLITE_PRINT_BUF_SIZE
192 # define SQLITE_PRINT_BUF_SIZE 350
193 #endif
194 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
195 
196 /*
197 ** The root program.  All variations call this core.
198 **
199 ** INPUTS:
200 **   func   This is a pointer to a function taking three arguments
201 **            1. A pointer to anything.  Same as the "arg" parameter.
202 **            2. A pointer to the list of characters to be output
203 **               (Note, this list is NOT null terminated.)
204 **            3. An integer number of characters to be output.
205 **               (Note: This number might be zero.)
206 **
207 **   arg    This is the pointer to anything which will be passed as the
208 **          first argument to "func".  Use it for whatever you like.
209 **
210 **   fmt    This is the format string, as in the usual print.
211 **
212 **   ap     This is a pointer to a list of arguments.  Same as in
213 **          vfprint.
214 **
215 ** OUTPUTS:
216 **          The return value is the total number of characters sent to
217 **          the function "func".  Returns -1 on a error.
218 **
219 ** Note that the order in which automatic variables are declared below
220 ** seems to make a big difference in determining how fast this beast
221 ** will run.
222 */
223 void sqlite3VXPrintf(
224   StrAccum *pAccum,                  /* Accumulate results here */
225   int useExtended,                   /* Allow extended %-conversions */
226   const char *fmt,                   /* Format string */
227   va_list ap                         /* arguments */
228 ){
229   int c;                     /* Next character in the format string */
230   char *bufpt;               /* Pointer to the conversion buffer */
231   int precision;             /* Precision of the current field */
232   int length;                /* Length of the field */
233   int idx;                   /* A general purpose loop counter */
234   int width;                 /* Width of the current field */
235   etByte flag_leftjustify;   /* True if "-" flag is present */
236   etByte flag_plussign;      /* True if "+" flag is present */
237   etByte flag_blanksign;     /* True if " " flag is present */
238   etByte flag_alternateform; /* True if "#" flag is present */
239   etByte flag_altform2;      /* True if "!" flag is present */
240   etByte flag_zeropad;       /* True if field width constant starts with zero */
241   etByte flag_long;          /* True if "l" flag is present */
242   etByte flag_longlong;      /* True if the "ll" flag is present */
243   etByte done;               /* Loop termination flag */
244   sqlite_uint64 longvalue;   /* Value for integer types */
245   LONGDOUBLE_TYPE realvalue; /* Value for real types */
246   const et_info *infop;      /* Pointer to the appropriate info structure */
247   char buf[etBUFSIZE];       /* Conversion buffer */
248   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
249   etByte errorflag = 0;      /* True if an error is encountered */
250   etByte xtype;              /* Conversion paradigm */
251   char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
252 #ifndef SQLITE_OMIT_FLOATING_POINT
253   int  exp, e2;              /* exponent of real numbers */
254   double rounder;            /* Used for rounding floating point values */
255   etByte flag_dp;            /* True if decimal point should be shown */
256   etByte flag_rtz;           /* True if trailing zeros should be removed */
257   etByte flag_exp;           /* True to force display of the exponent */
258   int nsd;                   /* Number of significant digits returned */
259 #endif
260 
261   length = 0;
262   bufpt = 0;
263   for(; (c=(*fmt))!=0; ++fmt){
264     if( c!='%' ){
265       int amt;
266       bufpt = (char *)fmt;
267       amt = 1;
268       while( (c=(*++fmt))!='%' && c!=0 ) amt++;
269       sqlite3StrAccumAppend(pAccum, bufpt, amt);
270       if( c==0 ) break;
271     }
272     if( (c=(*++fmt))==0 ){
273       errorflag = 1;
274       sqlite3StrAccumAppend(pAccum, "%", 1);
275       break;
276     }
277     /* Find out what flags are present */
278     flag_leftjustify = flag_plussign = flag_blanksign =
279      flag_alternateform = flag_altform2 = flag_zeropad = 0;
280     done = 0;
281     do{
282       switch( c ){
283         case '-':   flag_leftjustify = 1;     break;
284         case '+':   flag_plussign = 1;        break;
285         case ' ':   flag_blanksign = 1;       break;
286         case '#':   flag_alternateform = 1;   break;
287         case '!':   flag_altform2 = 1;        break;
288         case '0':   flag_zeropad = 1;         break;
289         default:    done = 1;                 break;
290       }
291     }while( !done && (c=(*++fmt))!=0 );
292     /* Get the field width */
293     width = 0;
294     if( c=='*' ){
295       width = va_arg(ap,int);
296       if( width<0 ){
297         flag_leftjustify = 1;
298         width = -width;
299       }
300       c = *++fmt;
301     }else{
302       while( c>='0' && c<='9' ){
303         width = width*10 + c - '0';
304         c = *++fmt;
305       }
306     }
307     if( width > etBUFSIZE-10 ){
308       width = etBUFSIZE-10;
309     }
310     /* Get the precision */
311     if( c=='.' ){
312       precision = 0;
313       c = *++fmt;
314       if( c=='*' ){
315         precision = va_arg(ap,int);
316         if( precision<0 ) precision = -precision;
317         c = *++fmt;
318       }else{
319         while( c>='0' && c<='9' ){
320           precision = precision*10 + c - '0';
321           c = *++fmt;
322         }
323       }
324     }else{
325       precision = -1;
326     }
327     /* Get the conversion type modifier */
328     if( c=='l' ){
329       flag_long = 1;
330       c = *++fmt;
331       if( c=='l' ){
332         flag_longlong = 1;
333         c = *++fmt;
334       }else{
335         flag_longlong = 0;
336       }
337     }else{
338       flag_long = flag_longlong = 0;
339     }
340     /* Fetch the info entry for the field */
341     infop = 0;
342     for(idx=0; idx<etNINFO; idx++){
343       if( c==fmtinfo[idx].fmttype ){
344         infop = &fmtinfo[idx];
345         if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
346           xtype = infop->type;
347         }else{
348           return;
349         }
350         break;
351       }
352     }
353     zExtra = 0;
354     if( infop==0 ){
355       return;
356     }
357 
358 
359     /* Limit the precision to prevent overflowing buf[] during conversion */
360     if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
361       precision = etBUFSIZE-40;
362     }
363 
364     /*
365     ** At this point, variables are initialized as follows:
366     **
367     **   flag_alternateform          TRUE if a '#' is present.
368     **   flag_altform2               TRUE if a '!' is present.
369     **   flag_plussign               TRUE if a '+' is present.
370     **   flag_leftjustify            TRUE if a '-' is present or if the
371     **                               field width was negative.
372     **   flag_zeropad                TRUE if the width began with 0.
373     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
374     **                               the conversion character.
375     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
376     **                               the conversion character.
377     **   flag_blanksign              TRUE if a ' ' is present.
378     **   width                       The specified field width.  This is
379     **                               always non-negative.  Zero is the default.
380     **   precision                   The specified precision.  The default
381     **                               is -1.
382     **   xtype                       The class of the conversion.
383     **   infop                       Pointer to the appropriate info struct.
384     */
385     switch( xtype ){
386       case etPOINTER:
387         flag_longlong = sizeof(char*)==sizeof(i64);
388         flag_long = sizeof(char*)==sizeof(long int);
389         /* Fall through into the next case */
390       case etORDINAL:
391       case etRADIX:
392         if( infop->flags & FLAG_SIGNED ){
393           i64 v;
394           if( flag_longlong )   v = va_arg(ap,i64);
395           else if( flag_long )  v = va_arg(ap,long int);
396           else                  v = va_arg(ap,int);
397           if( v<0 ){
398             longvalue = -v;
399             prefix = '-';
400           }else{
401             longvalue = v;
402             if( flag_plussign )        prefix = '+';
403             else if( flag_blanksign )  prefix = ' ';
404             else                       prefix = 0;
405           }
406         }else{
407           if( flag_longlong )   longvalue = va_arg(ap,u64);
408           else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
409           else                  longvalue = va_arg(ap,unsigned int);
410           prefix = 0;
411         }
412         if( longvalue==0 ) flag_alternateform = 0;
413         if( flag_zeropad && precision<width-(prefix!=0) ){
414           precision = width-(prefix!=0);
415         }
416         bufpt = &buf[etBUFSIZE-1];
417         if( xtype==etORDINAL ){
418           static const char zOrd[] = "thstndrd";
419           int x = longvalue % 10;
420           if( x>=4 || (longvalue/10)%10==1 ){
421             x = 0;
422           }
423           buf[etBUFSIZE-3] = zOrd[x*2];
424           buf[etBUFSIZE-2] = zOrd[x*2+1];
425           bufpt -= 2;
426         }
427         {
428           register const char *cset;      /* Use registers for speed */
429           register int base;
430           cset = &aDigits[infop->charset];
431           base = infop->base;
432           do{                                           /* Convert to ascii */
433             *(--bufpt) = cset[longvalue%base];
434             longvalue = longvalue/base;
435           }while( longvalue>0 );
436         }
437         length = &buf[etBUFSIZE-1]-bufpt;
438         for(idx=precision-length; idx>0; idx--){
439           *(--bufpt) = '0';                             /* Zero pad */
440         }
441         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
442         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
443           const char *pre;
444           char x;
445           pre = &aPrefix[infop->prefix];
446           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
447         }
448         length = &buf[etBUFSIZE-1]-bufpt;
449         break;
450       case etFLOAT:
451       case etEXP:
452       case etGENERIC:
453         realvalue = va_arg(ap,double);
454 #ifndef SQLITE_OMIT_FLOATING_POINT
455         if( precision<0 ) precision = 6;         /* Set default precision */
456         if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
457         if( realvalue<0.0 ){
458           realvalue = -realvalue;
459           prefix = '-';
460         }else{
461           if( flag_plussign )          prefix = '+';
462           else if( flag_blanksign )    prefix = ' ';
463           else                         prefix = 0;
464         }
465         if( xtype==etGENERIC && precision>0 ) precision--;
466 #if 0
467         /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
468         for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
469 #else
470         /* It makes more sense to use 0.5 */
471         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
472 #endif
473         if( xtype==etFLOAT ) realvalue += rounder;
474         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
475         exp = 0;
476         if( sqlite3IsNaN(realvalue) ){
477           bufpt = "NaN";
478           length = 3;
479           break;
480         }
481         if( realvalue>0.0 ){
482           while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
483           while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
484           while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
485           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
486           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
487           if( exp>350 ){
488             if( prefix=='-' ){
489               bufpt = "-Inf";
490             }else if( prefix=='+' ){
491               bufpt = "+Inf";
492             }else{
493               bufpt = "Inf";
494             }
495             length = strlen(bufpt);
496             break;
497           }
498         }
499         bufpt = buf;
500         /*
501         ** If the field type is etGENERIC, then convert to either etEXP
502         ** or etFLOAT, as appropriate.
503         */
504         flag_exp = xtype==etEXP;
505         if( xtype!=etFLOAT ){
506           realvalue += rounder;
507           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
508         }
509         if( xtype==etGENERIC ){
510           flag_rtz = !flag_alternateform;
511           if( exp<-4 || exp>precision ){
512             xtype = etEXP;
513           }else{
514             precision = precision - exp;
515             xtype = etFLOAT;
516           }
517         }else{
518           flag_rtz = 0;
519         }
520         if( xtype==etEXP ){
521           e2 = 0;
522         }else{
523           e2 = exp;
524         }
525         nsd = 0;
526         flag_dp = (precision>0) | flag_alternateform | flag_altform2;
527         /* The sign in front of the number */
528         if( prefix ){
529           *(bufpt++) = prefix;
530         }
531         /* Digits prior to the decimal point */
532         if( e2<0 ){
533           *(bufpt++) = '0';
534         }else{
535           for(; e2>=0; e2--){
536             *(bufpt++) = et_getdigit(&realvalue,&nsd);
537           }
538         }
539         /* The decimal point */
540         if( flag_dp ){
541           *(bufpt++) = '.';
542         }
543         /* "0" digits after the decimal point but before the first
544         ** significant digit of the number */
545         for(e2++; e2<0; precision--, e2++){
546           assert( precision>0 );
547           *(bufpt++) = '0';
548         }
549         /* Significant digits after the decimal point */
550         while( (precision--)>0 ){
551           *(bufpt++) = et_getdigit(&realvalue,&nsd);
552         }
553         /* Remove trailing zeros and the "." if no digits follow the "." */
554         if( flag_rtz && flag_dp ){
555           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
556           assert( bufpt>buf );
557           if( bufpt[-1]=='.' ){
558             if( flag_altform2 ){
559               *(bufpt++) = '0';
560             }else{
561               *(--bufpt) = 0;
562             }
563           }
564         }
565         /* Add the "eNNN" suffix */
566         if( flag_exp || xtype==etEXP ){
567           *(bufpt++) = aDigits[infop->charset];
568           if( exp<0 ){
569             *(bufpt++) = '-'; exp = -exp;
570           }else{
571             *(bufpt++) = '+';
572           }
573           if( exp>=100 ){
574             *(bufpt++) = (exp/100)+'0';                /* 100's digit */
575             exp %= 100;
576           }
577           *(bufpt++) = exp/10+'0';                     /* 10's digit */
578           *(bufpt++) = exp%10+'0';                     /* 1's digit */
579         }
580         *bufpt = 0;
581 
582         /* The converted number is in buf[] and zero terminated. Output it.
583         ** Note that the number is in the usual order, not reversed as with
584         ** integer conversions. */
585         length = bufpt-buf;
586         bufpt = buf;
587 
588         /* Special case:  Add leading zeros if the flag_zeropad flag is
589         ** set and we are not left justified */
590         if( flag_zeropad && !flag_leftjustify && length < width){
591           int i;
592           int nPad = width - length;
593           for(i=width; i>=nPad; i--){
594             bufpt[i] = bufpt[i-nPad];
595           }
596           i = prefix!=0;
597           while( nPad-- ) bufpt[i++] = '0';
598           length = width;
599         }
600 #endif
601         break;
602       case etSIZE:
603         *(va_arg(ap,int*)) = pAccum->nChar;
604         length = width = 0;
605         break;
606       case etPERCENT:
607         buf[0] = '%';
608         bufpt = buf;
609         length = 1;
610         break;
611       case etCHARX:
612         c = buf[0] = va_arg(ap,int);
613         if( precision>=0 ){
614           for(idx=1; idx<precision; idx++) buf[idx] = c;
615           length = precision;
616         }else{
617           length =1;
618         }
619         bufpt = buf;
620         break;
621       case etSTRING:
622       case etDYNSTRING:
623         bufpt = va_arg(ap,char*);
624         if( bufpt==0 ){
625           bufpt = "";
626         }else if( xtype==etDYNSTRING ){
627           zExtra = bufpt;
628         }
629         if( precision>=0 ){
630           for(length=0; length<precision && bufpt[length]; length++){}
631         }else{
632           length = strlen(bufpt);
633         }
634         break;
635       case etSQLESCAPE:
636       case etSQLESCAPE2:
637       case etSQLESCAPE3: {
638         int i, j, n, ch, isnull;
639         int needQuote;
640         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
641         char *escarg = va_arg(ap,char*);
642         isnull = escarg==0;
643         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
644         for(i=n=0; (ch=escarg[i])!=0; i++){
645           if( ch==q )  n++;
646         }
647         needQuote = !isnull && xtype==etSQLESCAPE2;
648         n += i + 1 + needQuote*2;
649         if( n>etBUFSIZE ){
650           bufpt = zExtra = sqlite3Malloc( n );
651           if( bufpt==0 ) return;
652         }else{
653           bufpt = buf;
654         }
655         j = 0;
656         if( needQuote ) bufpt[j++] = q;
657         for(i=0; (ch=escarg[i])!=0; i++){
658           bufpt[j++] = ch;
659           if( ch==q ) bufpt[j++] = ch;
660         }
661         if( needQuote ) bufpt[j++] = q;
662         bufpt[j] = 0;
663         length = j;
664         /* The precision is ignored on %q and %Q */
665         /* if( precision>=0 && precision<length ) length = precision; */
666         break;
667       }
668       case etTOKEN: {
669         Token *pToken = va_arg(ap, Token*);
670         if( pToken ){
671           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
672         }
673         length = width = 0;
674         break;
675       }
676       case etSRCLIST: {
677         SrcList *pSrc = va_arg(ap, SrcList*);
678         int k = va_arg(ap, int);
679         struct SrcList_item *pItem = &pSrc->a[k];
680         assert( k>=0 && k<pSrc->nSrc );
681         if( pItem->zDatabase ){
682           sqlite3StrAccumAppend(pAccum, pItem->zDatabase, -1);
683           sqlite3StrAccumAppend(pAccum, ".", 1);
684         }
685         sqlite3StrAccumAppend(pAccum, pItem->zName, -1);
686         length = width = 0;
687         break;
688       }
689     }/* End switch over the format type */
690     /*
691     ** The text of the conversion is pointed to by "bufpt" and is
692     ** "length" characters long.  The field width is "width".  Do
693     ** the output.
694     */
695     if( !flag_leftjustify ){
696       register int nspace;
697       nspace = width-length;
698       if( nspace>0 ){
699         appendSpace(pAccum, nspace);
700       }
701     }
702     if( length>0 ){
703       sqlite3StrAccumAppend(pAccum, bufpt, length);
704     }
705     if( flag_leftjustify ){
706       register int nspace;
707       nspace = width-length;
708       if( nspace>0 ){
709         appendSpace(pAccum, nspace);
710       }
711     }
712     if( zExtra ){
713       sqlite3_free(zExtra);
714     }
715   }/* End for loop over the format string */
716 } /* End of function */
717 
718 /*
719 ** Append N bytes of text from z to the StrAccum object.
720 */
721 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
722   if( p->tooBig | p->mallocFailed ){
723     return;
724   }
725   if( N<0 ){
726     N = strlen(z);
727   }
728   if( N==0 ){
729     return;
730   }
731   if( p->nChar+N >= p->nAlloc ){
732     char *zNew;
733     if( !p->useMalloc ){
734       p->tooBig = 1;
735       N = p->nAlloc - p->nChar - 1;
736       if( N<=0 ){
737         return;
738       }
739     }else{
740       i64 szNew = p->nChar;
741       szNew += N + 1;
742       if( szNew > p->mxAlloc ){
743         sqlite3StrAccumReset(p);
744         p->tooBig = 1;
745         return;
746       }else{
747         p->nAlloc = szNew;
748       }
749       zNew = sqlite3Malloc( p->nAlloc );
750       if( zNew ){
751         memcpy(zNew, p->zText, p->nChar);
752         sqlite3StrAccumReset(p);
753         p->zText = zNew;
754       }else{
755         p->mallocFailed = 1;
756         sqlite3StrAccumReset(p);
757         return;
758       }
759     }
760   }
761   memcpy(&p->zText[p->nChar], z, N);
762   p->nChar += N;
763 }
764 
765 /*
766 ** Finish off a string by making sure it is zero-terminated.
767 ** Return a pointer to the resulting string.  Return a NULL
768 ** pointer if any kind of error was encountered.
769 */
770 char *sqlite3StrAccumFinish(StrAccum *p){
771   if( p->zText ){
772     p->zText[p->nChar] = 0;
773     if( p->useMalloc && p->zText==p->zBase ){
774       p->zText = sqlite3Malloc( p->nChar+1 );
775       if( p->zText ){
776         memcpy(p->zText, p->zBase, p->nChar+1);
777       }else{
778         p->mallocFailed = 1;
779       }
780     }
781   }
782   return p->zText;
783 }
784 
785 /*
786 ** Reset an StrAccum string.  Reclaim all malloced memory.
787 */
788 void sqlite3StrAccumReset(StrAccum *p){
789   if( p->zText!=p->zBase ){
790     sqlite3_free(p->zText);
791   }
792   p->zText = 0;
793 }
794 
795 /*
796 ** Initialize a string accumulator
797 */
798 void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
799   p->zText = p->zBase = zBase;
800   p->nChar = 0;
801   p->nAlloc = n;
802   p->mxAlloc = mx;
803   p->useMalloc = 1;
804   p->tooBig = 0;
805   p->mallocFailed = 0;
806 }
807 
808 /*
809 ** Print into memory obtained from sqliteMalloc().  Use the internal
810 ** %-conversion extensions.
811 */
812 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
813   char *z;
814   char zBase[SQLITE_PRINT_BUF_SIZE];
815   StrAccum acc;
816   sqlite3StrAccumInit(&acc, zBase, sizeof(zBase),
817                       db ? db->aLimit[SQLITE_LIMIT_LENGTH] : SQLITE_MAX_LENGTH);
818   sqlite3VXPrintf(&acc, 1, zFormat, ap);
819   z = sqlite3StrAccumFinish(&acc);
820   if( acc.mallocFailed && db ){
821     db->mallocFailed = 1;
822   }
823   return z;
824 }
825 
826 /*
827 ** Print into memory obtained from sqliteMalloc().  Use the internal
828 ** %-conversion extensions.
829 */
830 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
831   va_list ap;
832   char *z;
833   va_start(ap, zFormat);
834   z = sqlite3VMPrintf(db, zFormat, ap);
835   va_end(ap);
836   return z;
837 }
838 
839 /*
840 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
841 ** %-conversion extensions.
842 */
843 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
844   char *z;
845   char zBase[SQLITE_PRINT_BUF_SIZE];
846   StrAccum acc;
847 #ifndef SQLITE_OMIT_AUTOINIT
848   if( sqlite3_initialize() ) return 0;
849 #endif
850   sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
851   sqlite3VXPrintf(&acc, 0, zFormat, ap);
852   z = sqlite3StrAccumFinish(&acc);
853   return z;
854 }
855 
856 /*
857 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
858 ** %-conversion extensions.
859 */
860 char *sqlite3_mprintf(const char *zFormat, ...){
861   va_list ap;
862   char *z;
863 #ifndef SQLITE_OMIT_AUTOINIT
864   if( sqlite3_initialize() ) return 0;
865 #endif
866   va_start(ap, zFormat);
867   z = sqlite3_vmprintf(zFormat, ap);
868   va_end(ap);
869   return z;
870 }
871 
872 /*
873 ** sqlite3_snprintf() works like snprintf() except that it ignores the
874 ** current locale settings.  This is important for SQLite because we
875 ** are not able to use a "," as the decimal point in place of "." as
876 ** specified by some locales.
877 */
878 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
879   char *z;
880   va_list ap;
881   StrAccum acc;
882 
883   if( n<=0 ){
884     return zBuf;
885   }
886   sqlite3StrAccumInit(&acc, zBuf, n, 0);
887   acc.useMalloc = 0;
888   va_start(ap,zFormat);
889   sqlite3VXPrintf(&acc, 0, zFormat, ap);
890   va_end(ap);
891   z = sqlite3StrAccumFinish(&acc);
892   return z;
893 }
894 
895 #if defined(SQLITE_DEBUG)
896 /*
897 ** A version of printf() that understands %lld.  Used for debugging.
898 ** The printf() built into some versions of windows does not understand %lld
899 ** and segfaults if you give it a long long int.
900 */
901 void sqlite3DebugPrintf(const char *zFormat, ...){
902   va_list ap;
903   StrAccum acc;
904   char zBuf[500];
905   sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
906   acc.useMalloc = 0;
907   va_start(ap,zFormat);
908   sqlite3VXPrintf(&acc, 0, zFormat, ap);
909   va_end(ap);
910   sqlite3StrAccumFinish(&acc);
911   fprintf(stdout,"%s", zBuf);
912   fflush(stdout);
913 }
914 #endif
915