xref: /sqlite-3.40.0/src/printf.c (revision 5d00d0a8)
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  They are very out-of-date but might be useful as
5 ** an historical reference.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 1.104 2009/06/03 01:24:54 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 #define etINVALID     0 /* Any unrecognized conversion type */
81 
82 
83 /*
84 ** An "etByte" is an 8-bit unsigned value.
85 */
86 typedef unsigned char etByte;
87 
88 /*
89 ** Each builtin conversion character (ex: the 'd' in "%d") is described
90 ** by an instance of the following structure
91 */
92 typedef struct et_info {   /* Information about each format field */
93   char fmttype;            /* The format field code letter */
94   etByte base;             /* The base for radix conversion */
95   etByte flags;            /* One or more of FLAG_ constants below */
96   etByte type;             /* Conversion paradigm */
97   etByte charset;          /* Offset into aDigits[] of the digits string */
98   etByte prefix;           /* Offset into aPrefix[] of the prefix string */
99 } et_info;
100 
101 /*
102 ** Allowed values for et_info.flags
103 */
104 #define FLAG_SIGNED  1     /* True if the value to convert is signed */
105 #define FLAG_INTERN  2     /* True if for internal use only */
106 #define FLAG_STRING  4     /* Allow infinity precision */
107 
108 
109 /*
110 ** The following table is searched linearly, so it is good to put the
111 ** most frequently used conversion types first.
112 */
113 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
114 static const char aPrefix[] = "-x0\000X0";
115 static const et_info fmtinfo[] = {
116   {  'd', 10, 1, etRADIX,      0,  0 },
117   {  's',  0, 4, etSTRING,     0,  0 },
118   {  'g',  0, 1, etGENERIC,    30, 0 },
119   {  'z',  0, 4, etDYNSTRING,  0,  0 },
120   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
121   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
122   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
123   {  'c',  0, 0, etCHARX,      0,  0 },
124   {  'o',  8, 0, etRADIX,      0,  2 },
125   {  'u', 10, 0, etRADIX,      0,  0 },
126   {  'x', 16, 0, etRADIX,      16, 1 },
127   {  'X', 16, 0, etRADIX,      0,  4 },
128 #ifndef SQLITE_OMIT_FLOATING_POINT
129   {  'f',  0, 1, etFLOAT,      0,  0 },
130   {  'e',  0, 1, etEXP,        30, 0 },
131   {  'E',  0, 1, etEXP,        14, 0 },
132   {  'G',  0, 1, etGENERIC,    14, 0 },
133 #endif
134   {  'i', 10, 1, etRADIX,      0,  0 },
135   {  'n',  0, 0, etSIZE,       0,  0 },
136   {  '%',  0, 0, etPERCENT,    0,  0 },
137   {  'p', 16, 0, etPOINTER,    0,  1 },
138 
139 /* All the rest have the FLAG_INTERN bit set and are thus for internal
140 ** use only */
141   {  'T',  0, 2, etTOKEN,      0,  0 },
142   {  'S',  0, 2, etSRCLIST,    0,  0 },
143   {  'r', 10, 3, etORDINAL,    0,  0 },
144 };
145 
146 /*
147 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
148 ** conversions will work.
149 */
150 #ifndef SQLITE_OMIT_FLOATING_POINT
151 /*
152 ** "*val" is a double such that 0.1 <= *val < 10.0
153 ** Return the ascii code for the leading digit of *val, then
154 ** multiply "*val" by 10.0 to renormalize.
155 **
156 ** Example:
157 **     input:     *val = 3.14159
158 **     output:    *val = 1.4159    function return = '3'
159 **
160 ** The counter *cnt is incremented each time.  After counter exceeds
161 ** 16 (the number of significant digits in a 64-bit float) '0' is
162 ** always returned.
163 */
164 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
165   int digit;
166   LONGDOUBLE_TYPE d;
167   if( (*cnt)++ >= 16 ) return '0';
168   digit = (int)*val;
169   d = digit;
170   digit += '0';
171   *val = (*val - d)*10.0;
172   return (char)digit;
173 }
174 #endif /* SQLITE_OMIT_FLOATING_POINT */
175 
176 /*
177 ** Append N space characters to the given string buffer.
178 */
179 static void appendSpace(StrAccum *pAccum, int N){
180   static const char zSpaces[] = "                             ";
181   while( N>=(int)sizeof(zSpaces)-1 ){
182     sqlite3StrAccumAppend(pAccum, zSpaces, sizeof(zSpaces)-1);
183     N -= sizeof(zSpaces)-1;
184   }
185   if( N>0 ){
186     sqlite3StrAccumAppend(pAccum, zSpaces, N);
187   }
188 }
189 
190 /*
191 ** On machines with a small stack size, you can redefine the
192 ** SQLITE_PRINT_BUF_SIZE to be less than 350.
193 */
194 #ifndef SQLITE_PRINT_BUF_SIZE
195 # if defined(SQLITE_SMALL_STACK)
196 #   define SQLITE_PRINT_BUF_SIZE 50
197 # else
198 #   define SQLITE_PRINT_BUF_SIZE 350
199 # endif
200 #endif
201 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
202 
203 /*
204 ** The root program.  All variations call this core.
205 **
206 ** INPUTS:
207 **   func   This is a pointer to a function taking three arguments
208 **            1. A pointer to anything.  Same as the "arg" parameter.
209 **            2. A pointer to the list of characters to be output
210 **               (Note, this list is NOT null terminated.)
211 **            3. An integer number of characters to be output.
212 **               (Note: This number might be zero.)
213 **
214 **   arg    This is the pointer to anything which will be passed as the
215 **          first argument to "func".  Use it for whatever you like.
216 **
217 **   fmt    This is the format string, as in the usual print.
218 **
219 **   ap     This is a pointer to a list of arguments.  Same as in
220 **          vfprint.
221 **
222 ** OUTPUTS:
223 **          The return value is the total number of characters sent to
224 **          the function "func".  Returns -1 on a error.
225 **
226 ** Note that the order in which automatic variables are declared below
227 ** seems to make a big difference in determining how fast this beast
228 ** will run.
229 */
230 void sqlite3VXPrintf(
231   StrAccum *pAccum,                  /* Accumulate results here */
232   int useExtended,                   /* Allow extended %-conversions */
233   const char *fmt,                   /* Format string */
234   va_list ap                         /* arguments */
235 ){
236   int c;                     /* Next character in the format string */
237   char *bufpt;               /* Pointer to the conversion buffer */
238   int precision;             /* Precision of the current field */
239   int length;                /* Length of the field */
240   int idx;                   /* A general purpose loop counter */
241   int width;                 /* Width of the current field */
242   etByte flag_leftjustify;   /* True if "-" flag is present */
243   etByte flag_plussign;      /* True if "+" flag is present */
244   etByte flag_blanksign;     /* True if " " flag is present */
245   etByte flag_alternateform; /* True if "#" flag is present */
246   etByte flag_altform2;      /* True if "!" flag is present */
247   etByte flag_zeropad;       /* True if field width constant starts with zero */
248   etByte flag_long;          /* True if "l" flag is present */
249   etByte flag_longlong;      /* True if the "ll" flag is present */
250   etByte done;               /* Loop termination flag */
251   sqlite_uint64 longvalue;   /* Value for integer types */
252   LONGDOUBLE_TYPE realvalue; /* Value for real types */
253   const et_info *infop;      /* Pointer to the appropriate info structure */
254   char buf[etBUFSIZE];       /* Conversion buffer */
255   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
256   etByte xtype = 0;          /* Conversion paradigm */
257   char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
258 #ifndef SQLITE_OMIT_FLOATING_POINT
259   int  exp, e2;              /* exponent of real numbers */
260   double rounder;            /* Used for rounding floating point values */
261   etByte flag_dp;            /* True if decimal point should be shown */
262   etByte flag_rtz;           /* True if trailing zeros should be removed */
263   etByte flag_exp;           /* True to force display of the exponent */
264   int nsd;                   /* Number of significant digits returned */
265 #endif
266 
267   length = 0;
268   bufpt = 0;
269   for(; (c=(*fmt))!=0; ++fmt){
270     if( c!='%' ){
271       int amt;
272       bufpt = (char *)fmt;
273       amt = 1;
274       while( (c=(*++fmt))!='%' && c!=0 ) amt++;
275       sqlite3StrAccumAppend(pAccum, bufpt, amt);
276       if( c==0 ) break;
277     }
278     if( (c=(*++fmt))==0 ){
279       sqlite3StrAccumAppend(pAccum, "%", 1);
280       break;
281     }
282     /* Find out what flags are present */
283     flag_leftjustify = flag_plussign = flag_blanksign =
284      flag_alternateform = flag_altform2 = flag_zeropad = 0;
285     done = 0;
286     do{
287       switch( c ){
288         case '-':   flag_leftjustify = 1;     break;
289         case '+':   flag_plussign = 1;        break;
290         case ' ':   flag_blanksign = 1;       break;
291         case '#':   flag_alternateform = 1;   break;
292         case '!':   flag_altform2 = 1;        break;
293         case '0':   flag_zeropad = 1;         break;
294         default:    done = 1;                 break;
295       }
296     }while( !done && (c=(*++fmt))!=0 );
297     /* Get the field width */
298     width = 0;
299     if( c=='*' ){
300       width = va_arg(ap,int);
301       if( width<0 ){
302         flag_leftjustify = 1;
303         width = -width;
304       }
305       c = *++fmt;
306     }else{
307       while( c>='0' && c<='9' ){
308         width = width*10 + c - '0';
309         c = *++fmt;
310       }
311     }
312     if( width > etBUFSIZE-10 ){
313       width = etBUFSIZE-10;
314     }
315     /* Get the precision */
316     if( c=='.' ){
317       precision = 0;
318       c = *++fmt;
319       if( c=='*' ){
320         precision = va_arg(ap,int);
321         if( precision<0 ) precision = -precision;
322         c = *++fmt;
323       }else{
324         while( c>='0' && c<='9' ){
325           precision = precision*10 + c - '0';
326           c = *++fmt;
327         }
328       }
329     }else{
330       precision = -1;
331     }
332     /* Get the conversion type modifier */
333     if( c=='l' ){
334       flag_long = 1;
335       c = *++fmt;
336       if( c=='l' ){
337         flag_longlong = 1;
338         c = *++fmt;
339       }else{
340         flag_longlong = 0;
341       }
342     }else{
343       flag_long = flag_longlong = 0;
344     }
345     /* Fetch the info entry for the field */
346     infop = &fmtinfo[0];
347     xtype = etINVALID;
348     for(idx=0; idx<ArraySize(fmtinfo); idx++){
349       if( c==fmtinfo[idx].fmttype ){
350         infop = &fmtinfo[idx];
351         if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
352           xtype = infop->type;
353         }else{
354           return;
355         }
356         break;
357       }
358     }
359     zExtra = 0;
360 
361 
362     /* Limit the precision to prevent overflowing buf[] during conversion */
363     if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
364       precision = etBUFSIZE-40;
365     }
366 
367     /*
368     ** At this point, variables are initialized as follows:
369     **
370     **   flag_alternateform          TRUE if a '#' is present.
371     **   flag_altform2               TRUE if a '!' is present.
372     **   flag_plussign               TRUE if a '+' is present.
373     **   flag_leftjustify            TRUE if a '-' is present or if the
374     **                               field width was negative.
375     **   flag_zeropad                TRUE if the width began with 0.
376     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
377     **                               the conversion character.
378     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
379     **                               the conversion character.
380     **   flag_blanksign              TRUE if a ' ' is present.
381     **   width                       The specified field width.  This is
382     **                               always non-negative.  Zero is the default.
383     **   precision                   The specified precision.  The default
384     **                               is -1.
385     **   xtype                       The class of the conversion.
386     **   infop                       Pointer to the appropriate info struct.
387     */
388     switch( xtype ){
389       case etPOINTER:
390         flag_longlong = sizeof(char*)==sizeof(i64);
391         flag_long = sizeof(char*)==sizeof(long int);
392         /* Fall through into the next case */
393       case etORDINAL:
394       case etRADIX:
395         if( infop->flags & FLAG_SIGNED ){
396           i64 v;
397           if( flag_longlong ){
398             v = va_arg(ap,i64);
399           }else if( flag_long ){
400             v = va_arg(ap,long int);
401           }else{
402             v = va_arg(ap,int);
403           }
404           if( v<0 ){
405             longvalue = -v;
406             prefix = '-';
407           }else{
408             longvalue = v;
409             if( flag_plussign )        prefix = '+';
410             else if( flag_blanksign )  prefix = ' ';
411             else                       prefix = 0;
412           }
413         }else{
414           if( flag_longlong ){
415             longvalue = va_arg(ap,u64);
416           }else if( flag_long ){
417             longvalue = va_arg(ap,unsigned long int);
418           }else{
419             longvalue = va_arg(ap,unsigned int);
420           }
421           prefix = 0;
422         }
423         if( longvalue==0 ) flag_alternateform = 0;
424         if( flag_zeropad && precision<width-(prefix!=0) ){
425           precision = width-(prefix!=0);
426         }
427         bufpt = &buf[etBUFSIZE-1];
428         if( xtype==etORDINAL ){
429           static const char zOrd[] = "thstndrd";
430           int x = (int)(longvalue % 10);
431           if( x>=4 || (longvalue/10)%10==1 ){
432             x = 0;
433           }
434           buf[etBUFSIZE-3] = zOrd[x*2];
435           buf[etBUFSIZE-2] = zOrd[x*2+1];
436           bufpt -= 2;
437         }
438         {
439           register const char *cset;      /* Use registers for speed */
440           register int base;
441           cset = &aDigits[infop->charset];
442           base = infop->base;
443           do{                                           /* Convert to ascii */
444             *(--bufpt) = cset[longvalue%base];
445             longvalue = longvalue/base;
446           }while( longvalue>0 );
447         }
448         length = (int)(&buf[etBUFSIZE-1]-bufpt);
449         for(idx=precision-length; idx>0; idx--){
450           *(--bufpt) = '0';                             /* Zero pad */
451         }
452         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
453         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
454           const char *pre;
455           char x;
456           pre = &aPrefix[infop->prefix];
457           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
458         }
459         length = (int)(&buf[etBUFSIZE-1]-bufpt);
460         break;
461       case etFLOAT:
462       case etEXP:
463       case etGENERIC:
464         realvalue = va_arg(ap,double);
465 #ifndef SQLITE_OMIT_FLOATING_POINT
466         if( precision<0 ) precision = 6;         /* Set default precision */
467         if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
468         if( realvalue<0.0 ){
469           realvalue = -realvalue;
470           prefix = '-';
471         }else{
472           if( flag_plussign )          prefix = '+';
473           else if( flag_blanksign )    prefix = ' ';
474           else                         prefix = 0;
475         }
476         if( xtype==etGENERIC && precision>0 ) precision--;
477 #if 0
478         /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
479         for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
480 #else
481         /* It makes more sense to use 0.5 */
482         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
483 #endif
484         if( xtype==etFLOAT ) realvalue += rounder;
485         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
486         exp = 0;
487         if( sqlite3IsNaN((double)realvalue) ){
488           bufpt = "NaN";
489           length = 3;
490           break;
491         }
492         if( realvalue>0.0 ){
493           while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
494           while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
495           while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
496           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
497           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
498           if( exp>350 ){
499             if( prefix=='-' ){
500               bufpt = "-Inf";
501             }else if( prefix=='+' ){
502               bufpt = "+Inf";
503             }else{
504               bufpt = "Inf";
505             }
506             length = sqlite3Strlen30(bufpt);
507             break;
508           }
509         }
510         bufpt = buf;
511         /*
512         ** If the field type is etGENERIC, then convert to either etEXP
513         ** or etFLOAT, as appropriate.
514         */
515         flag_exp = xtype==etEXP;
516         if( xtype!=etFLOAT ){
517           realvalue += rounder;
518           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
519         }
520         if( xtype==etGENERIC ){
521           flag_rtz = !flag_alternateform;
522           if( exp<-4 || exp>precision ){
523             xtype = etEXP;
524           }else{
525             precision = precision - exp;
526             xtype = etFLOAT;
527           }
528         }else{
529           flag_rtz = 0;
530         }
531         if( xtype==etEXP ){
532           e2 = 0;
533         }else{
534           e2 = exp;
535         }
536         nsd = 0;
537         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
538         /* The sign in front of the number */
539         if( prefix ){
540           *(bufpt++) = prefix;
541         }
542         /* Digits prior to the decimal point */
543         if( e2<0 ){
544           *(bufpt++) = '0';
545         }else{
546           for(; e2>=0; e2--){
547             *(bufpt++) = et_getdigit(&realvalue,&nsd);
548           }
549         }
550         /* The decimal point */
551         if( flag_dp ){
552           *(bufpt++) = '.';
553         }
554         /* "0" digits after the decimal point but before the first
555         ** significant digit of the number */
556         for(e2++; e2<0; precision--, e2++){
557           assert( precision>0 );
558           *(bufpt++) = '0';
559         }
560         /* Significant digits after the decimal point */
561         while( (precision--)>0 ){
562           *(bufpt++) = et_getdigit(&realvalue,&nsd);
563         }
564         /* Remove trailing zeros and the "." if no digits follow the "." */
565         if( flag_rtz && flag_dp ){
566           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
567           assert( bufpt>buf );
568           if( bufpt[-1]=='.' ){
569             if( flag_altform2 ){
570               *(bufpt++) = '0';
571             }else{
572               *(--bufpt) = 0;
573             }
574           }
575         }
576         /* Add the "eNNN" suffix */
577         if( flag_exp || xtype==etEXP ){
578           *(bufpt++) = aDigits[infop->charset];
579           if( exp<0 ){
580             *(bufpt++) = '-'; exp = -exp;
581           }else{
582             *(bufpt++) = '+';
583           }
584           if( exp>=100 ){
585             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */
586             exp %= 100;
587           }
588           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */
589           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */
590         }
591         *bufpt = 0;
592 
593         /* The converted number is in buf[] and zero terminated. Output it.
594         ** Note that the number is in the usual order, not reversed as with
595         ** integer conversions. */
596         length = (int)(bufpt-buf);
597         bufpt = buf;
598 
599         /* Special case:  Add leading zeros if the flag_zeropad flag is
600         ** set and we are not left justified */
601         if( flag_zeropad && !flag_leftjustify && length < width){
602           int i;
603           int nPad = width - length;
604           for(i=width; i>=nPad; i--){
605             bufpt[i] = bufpt[i-nPad];
606           }
607           i = prefix!=0;
608           while( nPad-- ) bufpt[i++] = '0';
609           length = width;
610         }
611 #endif
612         break;
613       case etSIZE:
614         *(va_arg(ap,int*)) = pAccum->nChar;
615         length = width = 0;
616         break;
617       case etPERCENT:
618         buf[0] = '%';
619         bufpt = buf;
620         length = 1;
621         break;
622       case etCHARX:
623         c = va_arg(ap,int);
624         buf[0] = (char)c;
625         if( precision>=0 ){
626           for(idx=1; idx<precision; idx++) buf[idx] = (char)c;
627           length = precision;
628         }else{
629           length =1;
630         }
631         bufpt = buf;
632         break;
633       case etSTRING:
634       case etDYNSTRING:
635         bufpt = va_arg(ap,char*);
636         if( bufpt==0 ){
637           bufpt = "";
638         }else if( xtype==etDYNSTRING ){
639           zExtra = bufpt;
640         }
641         if( precision>=0 ){
642           for(length=0; length<precision && bufpt[length]; length++){}
643         }else{
644           length = sqlite3Strlen30(bufpt);
645         }
646         break;
647       case etSQLESCAPE:
648       case etSQLESCAPE2:
649       case etSQLESCAPE3: {
650         int i, j, n, isnull;
651         int needQuote;
652         char ch;
653         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
654         char *escarg = va_arg(ap,char*);
655         isnull = escarg==0;
656         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
657         for(i=n=0; (ch=escarg[i])!=0; i++){
658           if( ch==q )  n++;
659         }
660         needQuote = !isnull && xtype==etSQLESCAPE2;
661         n += i + 1 + needQuote*2;
662         if( n>etBUFSIZE ){
663           bufpt = zExtra = sqlite3Malloc( n );
664           if( bufpt==0 ){
665             pAccum->mallocFailed = 1;
666             return;
667           }
668         }else{
669           bufpt = buf;
670         }
671         j = 0;
672         if( needQuote ) bufpt[j++] = q;
673         for(i=0; (ch=escarg[i])!=0; i++){
674           bufpt[j++] = ch;
675           if( ch==q ) bufpt[j++] = ch;
676         }
677         if( needQuote ) bufpt[j++] = q;
678         bufpt[j] = 0;
679         length = j;
680         /* The precision is ignored on %q and %Q */
681         /* if( precision>=0 && precision<length ) length = precision; */
682         break;
683       }
684       case etTOKEN: {
685         Token *pToken = va_arg(ap, Token*);
686         if( pToken ){
687           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
688         }
689         length = width = 0;
690         break;
691       }
692       case etSRCLIST: {
693         SrcList *pSrc = va_arg(ap, SrcList*);
694         int k = va_arg(ap, int);
695         struct SrcList_item *pItem = &pSrc->a[k];
696         assert( k>=0 && k<pSrc->nSrc );
697         if( pItem->zDatabase ){
698           sqlite3StrAccumAppend(pAccum, pItem->zDatabase, -1);
699           sqlite3StrAccumAppend(pAccum, ".", 1);
700         }
701         sqlite3StrAccumAppend(pAccum, pItem->zName, -1);
702         length = width = 0;
703         break;
704       }
705       default: {
706         assert( xtype==etINVALID );
707         return;
708       }
709     }/* End switch over the format type */
710     /*
711     ** The text of the conversion is pointed to by "bufpt" and is
712     ** "length" characters long.  The field width is "width".  Do
713     ** the output.
714     */
715     if( !flag_leftjustify ){
716       register int nspace;
717       nspace = width-length;
718       if( nspace>0 ){
719         appendSpace(pAccum, nspace);
720       }
721     }
722     if( length>0 ){
723       sqlite3StrAccumAppend(pAccum, bufpt, length);
724     }
725     if( flag_leftjustify ){
726       register int nspace;
727       nspace = width-length;
728       if( nspace>0 ){
729         appendSpace(pAccum, nspace);
730       }
731     }
732     if( zExtra ){
733       sqlite3_free(zExtra);
734     }
735   }/* End for loop over the format string */
736 } /* End of function */
737 
738 /*
739 ** Append N bytes of text from z to the StrAccum object.
740 */
741 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
742   assert( z!=0 || N==0 );
743   if( p->tooBig | p->mallocFailed ){
744     testcase(p->tooBig);
745     testcase(p->mallocFailed);
746     return;
747   }
748   if( N<0 ){
749     N = sqlite3Strlen30(z);
750   }
751   if( N==0 || NEVER(z==0) ){
752     return;
753   }
754   if( p->nChar+N >= p->nAlloc ){
755     char *zNew;
756     if( !p->useMalloc ){
757       p->tooBig = 1;
758       N = p->nAlloc - p->nChar - 1;
759       if( N<=0 ){
760         return;
761       }
762     }else{
763       i64 szNew = p->nChar;
764       szNew += N + 1;
765       if( szNew > p->mxAlloc ){
766         sqlite3StrAccumReset(p);
767         p->tooBig = 1;
768         return;
769       }else{
770         p->nAlloc = (int)szNew;
771       }
772       zNew = sqlite3DbMallocRaw(p->db, p->nAlloc );
773       if( zNew ){
774         memcpy(zNew, p->zText, p->nChar);
775         sqlite3StrAccumReset(p);
776         p->zText = zNew;
777       }else{
778         p->mallocFailed = 1;
779         sqlite3StrAccumReset(p);
780         return;
781       }
782     }
783   }
784   memcpy(&p->zText[p->nChar], z, N);
785   p->nChar += N;
786 }
787 
788 /*
789 ** Finish off a string by making sure it is zero-terminated.
790 ** Return a pointer to the resulting string.  Return a NULL
791 ** pointer if any kind of error was encountered.
792 */
793 char *sqlite3StrAccumFinish(StrAccum *p){
794   if( p->zText ){
795     p->zText[p->nChar] = 0;
796     if( p->useMalloc && p->zText==p->zBase ){
797       p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
798       if( p->zText ){
799         memcpy(p->zText, p->zBase, p->nChar+1);
800       }else{
801         p->mallocFailed = 1;
802       }
803     }
804   }
805   return p->zText;
806 }
807 
808 /*
809 ** Reset an StrAccum string.  Reclaim all malloced memory.
810 */
811 void sqlite3StrAccumReset(StrAccum *p){
812   if( p->zText!=p->zBase ){
813     sqlite3DbFree(p->db, p->zText);
814   }
815   p->zText = 0;
816 }
817 
818 /*
819 ** Initialize a string accumulator
820 */
821 void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
822   p->zText = p->zBase = zBase;
823   p->db = 0;
824   p->nChar = 0;
825   p->nAlloc = n;
826   p->mxAlloc = mx;
827   p->useMalloc = 1;
828   p->tooBig = 0;
829   p->mallocFailed = 0;
830 }
831 
832 /*
833 ** Print into memory obtained from sqliteMalloc().  Use the internal
834 ** %-conversion extensions.
835 */
836 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
837   char *z;
838   char zBase[SQLITE_PRINT_BUF_SIZE];
839   StrAccum acc;
840   assert( db!=0 );
841   sqlite3StrAccumInit(&acc, zBase, sizeof(zBase),
842                       db->aLimit[SQLITE_LIMIT_LENGTH]);
843   acc.db = db;
844   sqlite3VXPrintf(&acc, 1, zFormat, ap);
845   z = sqlite3StrAccumFinish(&acc);
846   if( acc.mallocFailed ){
847     db->mallocFailed = 1;
848   }
849   return z;
850 }
851 
852 /*
853 ** Print into memory obtained from sqliteMalloc().  Use the internal
854 ** %-conversion extensions.
855 */
856 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
857   va_list ap;
858   char *z;
859   va_start(ap, zFormat);
860   z = sqlite3VMPrintf(db, zFormat, ap);
861   va_end(ap);
862   return z;
863 }
864 
865 /*
866 ** Like sqlite3MPrintf(), but call sqlite3DbFree() on zStr after formatting
867 ** the string and before returnning.  This routine is intended to be used
868 ** to modify an existing string.  For example:
869 **
870 **       x = sqlite3MPrintf(db, x, "prefix %s suffix", x);
871 **
872 */
873 char *sqlite3MAppendf(sqlite3 *db, char *zStr, const char *zFormat, ...){
874   va_list ap;
875   char *z;
876   va_start(ap, zFormat);
877   z = sqlite3VMPrintf(db, zFormat, ap);
878   va_end(ap);
879   sqlite3DbFree(db, zStr);
880   return z;
881 }
882 
883 /*
884 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
885 ** %-conversion extensions.
886 */
887 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
888   char *z;
889   char zBase[SQLITE_PRINT_BUF_SIZE];
890   StrAccum acc;
891 #ifndef SQLITE_OMIT_AUTOINIT
892   if( sqlite3_initialize() ) return 0;
893 #endif
894   sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
895   sqlite3VXPrintf(&acc, 0, zFormat, ap);
896   z = sqlite3StrAccumFinish(&acc);
897   return z;
898 }
899 
900 /*
901 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
902 ** %-conversion extensions.
903 */
904 char *sqlite3_mprintf(const char *zFormat, ...){
905   va_list ap;
906   char *z;
907 #ifndef SQLITE_OMIT_AUTOINIT
908   if( sqlite3_initialize() ) return 0;
909 #endif
910   va_start(ap, zFormat);
911   z = sqlite3_vmprintf(zFormat, ap);
912   va_end(ap);
913   return z;
914 }
915 
916 /*
917 ** sqlite3_snprintf() works like snprintf() except that it ignores the
918 ** current locale settings.  This is important for SQLite because we
919 ** are not able to use a "," as the decimal point in place of "." as
920 ** specified by some locales.
921 */
922 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
923   char *z;
924   va_list ap;
925   StrAccum acc;
926 
927   if( n<=0 ){
928     return zBuf;
929   }
930   sqlite3StrAccumInit(&acc, zBuf, n, 0);
931   acc.useMalloc = 0;
932   va_start(ap,zFormat);
933   sqlite3VXPrintf(&acc, 0, zFormat, ap);
934   va_end(ap);
935   z = sqlite3StrAccumFinish(&acc);
936   return z;
937 }
938 
939 #if defined(SQLITE_DEBUG)
940 /*
941 ** A version of printf() that understands %lld.  Used for debugging.
942 ** The printf() built into some versions of windows does not understand %lld
943 ** and segfaults if you give it a long long int.
944 */
945 void sqlite3DebugPrintf(const char *zFormat, ...){
946   va_list ap;
947   StrAccum acc;
948   char zBuf[500];
949   sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
950   acc.useMalloc = 0;
951   va_start(ap,zFormat);
952   sqlite3VXPrintf(&acc, 0, zFormat, ap);
953   va_end(ap);
954   sqlite3StrAccumFinish(&acc);
955   fprintf(stdout,"%s", zBuf);
956   fflush(stdout);
957 }
958 #endif
959