xref: /sqlite-3.40.0/src/printf.c (revision 1c826650)
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  They are very out-of-date but might be useful as
5 ** an historical reference.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 1.94 2008/08/22 14:08:36 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 xtype;              /* Conversion paradigm */
250   char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
251 #ifndef SQLITE_OMIT_FLOATING_POINT
252   int  exp, e2;              /* exponent of real numbers */
253   double rounder;            /* Used for rounding floating point values */
254   etByte flag_dp;            /* True if decimal point should be shown */
255   etByte flag_rtz;           /* True if trailing zeros should be removed */
256   etByte flag_exp;           /* True to force display of the exponent */
257   int nsd;                   /* Number of significant digits returned */
258 #endif
259 
260   length = 0;
261   bufpt = 0;
262   for(; (c=(*fmt))!=0; ++fmt){
263     if( c!='%' ){
264       int amt;
265       bufpt = (char *)fmt;
266       amt = 1;
267       while( (c=(*++fmt))!='%' && c!=0 ) amt++;
268       sqlite3StrAccumAppend(pAccum, bufpt, amt);
269       if( c==0 ) break;
270     }
271     if( (c=(*++fmt))==0 ){
272       sqlite3StrAccumAppend(pAccum, "%", 1);
273       break;
274     }
275     /* Find out what flags are present */
276     flag_leftjustify = flag_plussign = flag_blanksign =
277      flag_alternateform = flag_altform2 = flag_zeropad = 0;
278     done = 0;
279     do{
280       switch( c ){
281         case '-':   flag_leftjustify = 1;     break;
282         case '+':   flag_plussign = 1;        break;
283         case ' ':   flag_blanksign = 1;       break;
284         case '#':   flag_alternateform = 1;   break;
285         case '!':   flag_altform2 = 1;        break;
286         case '0':   flag_zeropad = 1;         break;
287         default:    done = 1;                 break;
288       }
289     }while( !done && (c=(*++fmt))!=0 );
290     /* Get the field width */
291     width = 0;
292     if( c=='*' ){
293       width = va_arg(ap,int);
294       if( width<0 ){
295         flag_leftjustify = 1;
296         width = -width;
297       }
298       c = *++fmt;
299     }else{
300       while( c>='0' && c<='9' ){
301         width = width*10 + c - '0';
302         c = *++fmt;
303       }
304     }
305     if( width > etBUFSIZE-10 ){
306       width = etBUFSIZE-10;
307     }
308     /* Get the precision */
309     if( c=='.' ){
310       precision = 0;
311       c = *++fmt;
312       if( c=='*' ){
313         precision = va_arg(ap,int);
314         if( precision<0 ) precision = -precision;
315         c = *++fmt;
316       }else{
317         while( c>='0' && c<='9' ){
318           precision = precision*10 + c - '0';
319           c = *++fmt;
320         }
321       }
322     }else{
323       precision = -1;
324     }
325     /* Get the conversion type modifier */
326     if( c=='l' ){
327       flag_long = 1;
328       c = *++fmt;
329       if( c=='l' ){
330         flag_longlong = 1;
331         c = *++fmt;
332       }else{
333         flag_longlong = 0;
334       }
335     }else{
336       flag_long = flag_longlong = 0;
337     }
338     /* Fetch the info entry for the field */
339     infop = 0;
340     for(idx=0; idx<etNINFO; idx++){
341       if( c==fmtinfo[idx].fmttype ){
342         infop = &fmtinfo[idx];
343         if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
344           xtype = infop->type;
345         }else{
346           return;
347         }
348         break;
349       }
350     }
351     zExtra = 0;
352     if( infop==0 ){
353       return;
354     }
355 
356 
357     /* Limit the precision to prevent overflowing buf[] during conversion */
358     if( precision>etBUFSIZE-40 && (infop->flags & FLAG_STRING)==0 ){
359       precision = etBUFSIZE-40;
360     }
361 
362     /*
363     ** At this point, variables are initialized as follows:
364     **
365     **   flag_alternateform          TRUE if a '#' is present.
366     **   flag_altform2               TRUE if a '!' is present.
367     **   flag_plussign               TRUE if a '+' is present.
368     **   flag_leftjustify            TRUE if a '-' is present or if the
369     **                               field width was negative.
370     **   flag_zeropad                TRUE if the width began with 0.
371     **   flag_long                   TRUE if the letter 'l' (ell) prefixed
372     **                               the conversion character.
373     **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
374     **                               the conversion character.
375     **   flag_blanksign              TRUE if a ' ' is present.
376     **   width                       The specified field width.  This is
377     **                               always non-negative.  Zero is the default.
378     **   precision                   The specified precision.  The default
379     **                               is -1.
380     **   xtype                       The class of the conversion.
381     **   infop                       Pointer to the appropriate info struct.
382     */
383     switch( xtype ){
384       case etPOINTER:
385         flag_longlong = sizeof(char*)==sizeof(i64);
386         flag_long = sizeof(char*)==sizeof(long int);
387         /* Fall through into the next case */
388       case etORDINAL:
389       case etRADIX:
390         if( infop->flags & FLAG_SIGNED ){
391           i64 v;
392           if( flag_longlong )   v = va_arg(ap,i64);
393           else if( flag_long )  v = va_arg(ap,long int);
394           else                  v = va_arg(ap,int);
395           if( v<0 ){
396             longvalue = -v;
397             prefix = '-';
398           }else{
399             longvalue = v;
400             if( flag_plussign )        prefix = '+';
401             else if( flag_blanksign )  prefix = ' ';
402             else                       prefix = 0;
403           }
404         }else{
405           if( flag_longlong )   longvalue = va_arg(ap,u64);
406           else if( flag_long )  longvalue = va_arg(ap,unsigned long int);
407           else                  longvalue = va_arg(ap,unsigned int);
408           prefix = 0;
409         }
410         if( longvalue==0 ) flag_alternateform = 0;
411         if( flag_zeropad && precision<width-(prefix!=0) ){
412           precision = width-(prefix!=0);
413         }
414         bufpt = &buf[etBUFSIZE-1];
415         if( xtype==etORDINAL ){
416           static const char zOrd[] = "thstndrd";
417           int x = longvalue % 10;
418           if( x>=4 || (longvalue/10)%10==1 ){
419             x = 0;
420           }
421           buf[etBUFSIZE-3] = zOrd[x*2];
422           buf[etBUFSIZE-2] = zOrd[x*2+1];
423           bufpt -= 2;
424         }
425         {
426           register const char *cset;      /* Use registers for speed */
427           register int base;
428           cset = &aDigits[infop->charset];
429           base = infop->base;
430           do{                                           /* Convert to ascii */
431             *(--bufpt) = cset[longvalue%base];
432             longvalue = longvalue/base;
433           }while( longvalue>0 );
434         }
435         length = &buf[etBUFSIZE-1]-bufpt;
436         for(idx=precision-length; idx>0; idx--){
437           *(--bufpt) = '0';                             /* Zero pad */
438         }
439         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
440         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
441           const char *pre;
442           char x;
443           pre = &aPrefix[infop->prefix];
444           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
445         }
446         length = &buf[etBUFSIZE-1]-bufpt;
447         break;
448       case etFLOAT:
449       case etEXP:
450       case etGENERIC:
451         realvalue = va_arg(ap,double);
452 #ifndef SQLITE_OMIT_FLOATING_POINT
453         if( precision<0 ) precision = 6;         /* Set default precision */
454         if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
455         if( realvalue<0.0 ){
456           realvalue = -realvalue;
457           prefix = '-';
458         }else{
459           if( flag_plussign )          prefix = '+';
460           else if( flag_blanksign )    prefix = ' ';
461           else                         prefix = 0;
462         }
463         if( xtype==etGENERIC && precision>0 ) precision--;
464 #if 0
465         /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
466         for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
467 #else
468         /* It makes more sense to use 0.5 */
469         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
470 #endif
471         if( xtype==etFLOAT ) realvalue += rounder;
472         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
473         exp = 0;
474         if( sqlite3IsNaN(realvalue) ){
475           bufpt = "NaN";
476           length = 3;
477           break;
478         }
479         if( realvalue>0.0 ){
480           while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
481           while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
482           while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
483           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
484           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
485           if( exp>350 ){
486             if( prefix=='-' ){
487               bufpt = "-Inf";
488             }else if( prefix=='+' ){
489               bufpt = "+Inf";
490             }else{
491               bufpt = "Inf";
492             }
493             length = strlen(bufpt);
494             break;
495           }
496         }
497         bufpt = buf;
498         /*
499         ** If the field type is etGENERIC, then convert to either etEXP
500         ** or etFLOAT, as appropriate.
501         */
502         flag_exp = xtype==etEXP;
503         if( xtype!=etFLOAT ){
504           realvalue += rounder;
505           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
506         }
507         if( xtype==etGENERIC ){
508           flag_rtz = !flag_alternateform;
509           if( exp<-4 || exp>precision ){
510             xtype = etEXP;
511           }else{
512             precision = precision - exp;
513             xtype = etFLOAT;
514           }
515         }else{
516           flag_rtz = 0;
517         }
518         if( xtype==etEXP ){
519           e2 = 0;
520         }else{
521           e2 = exp;
522         }
523         nsd = 0;
524         flag_dp = (precision>0) | flag_alternateform | flag_altform2;
525         /* The sign in front of the number */
526         if( prefix ){
527           *(bufpt++) = prefix;
528         }
529         /* Digits prior to the decimal point */
530         if( e2<0 ){
531           *(bufpt++) = '0';
532         }else{
533           for(; e2>=0; e2--){
534             *(bufpt++) = et_getdigit(&realvalue,&nsd);
535           }
536         }
537         /* The decimal point */
538         if( flag_dp ){
539           *(bufpt++) = '.';
540         }
541         /* "0" digits after the decimal point but before the first
542         ** significant digit of the number */
543         for(e2++; e2<0; precision--, e2++){
544           assert( precision>0 );
545           *(bufpt++) = '0';
546         }
547         /* Significant digits after the decimal point */
548         while( (precision--)>0 ){
549           *(bufpt++) = et_getdigit(&realvalue,&nsd);
550         }
551         /* Remove trailing zeros and the "." if no digits follow the "." */
552         if( flag_rtz && flag_dp ){
553           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
554           assert( bufpt>buf );
555           if( bufpt[-1]=='.' ){
556             if( flag_altform2 ){
557               *(bufpt++) = '0';
558             }else{
559               *(--bufpt) = 0;
560             }
561           }
562         }
563         /* Add the "eNNN" suffix */
564         if( flag_exp || xtype==etEXP ){
565           *(bufpt++) = aDigits[infop->charset];
566           if( exp<0 ){
567             *(bufpt++) = '-'; exp = -exp;
568           }else{
569             *(bufpt++) = '+';
570           }
571           if( exp>=100 ){
572             *(bufpt++) = (exp/100)+'0';                /* 100's digit */
573             exp %= 100;
574           }
575           *(bufpt++) = exp/10+'0';                     /* 10's digit */
576           *(bufpt++) = exp%10+'0';                     /* 1's digit */
577         }
578         *bufpt = 0;
579 
580         /* The converted number is in buf[] and zero terminated. Output it.
581         ** Note that the number is in the usual order, not reversed as with
582         ** integer conversions. */
583         length = bufpt-buf;
584         bufpt = buf;
585 
586         /* Special case:  Add leading zeros if the flag_zeropad flag is
587         ** set and we are not left justified */
588         if( flag_zeropad && !flag_leftjustify && length < width){
589           int i;
590           int nPad = width - length;
591           for(i=width; i>=nPad; i--){
592             bufpt[i] = bufpt[i-nPad];
593           }
594           i = prefix!=0;
595           while( nPad-- ) bufpt[i++] = '0';
596           length = width;
597         }
598 #endif
599         break;
600       case etSIZE:
601         *(va_arg(ap,int*)) = pAccum->nChar;
602         length = width = 0;
603         break;
604       case etPERCENT:
605         buf[0] = '%';
606         bufpt = buf;
607         length = 1;
608         break;
609       case etCHARX:
610         c = buf[0] = va_arg(ap,int);
611         if( precision>=0 ){
612           for(idx=1; idx<precision; idx++) buf[idx] = c;
613           length = precision;
614         }else{
615           length =1;
616         }
617         bufpt = buf;
618         break;
619       case etSTRING:
620       case etDYNSTRING:
621         bufpt = va_arg(ap,char*);
622         if( bufpt==0 ){
623           bufpt = "";
624         }else if( xtype==etDYNSTRING ){
625           zExtra = bufpt;
626         }
627         if( precision>=0 ){
628           for(length=0; length<precision && bufpt[length]; length++){}
629         }else{
630           length = strlen(bufpt);
631         }
632         break;
633       case etSQLESCAPE:
634       case etSQLESCAPE2:
635       case etSQLESCAPE3: {
636         int i, j, n, ch, isnull;
637         int needQuote;
638         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
639         char *escarg = va_arg(ap,char*);
640         isnull = escarg==0;
641         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
642         for(i=n=0; (ch=escarg[i])!=0; i++){
643           if( ch==q )  n++;
644         }
645         needQuote = !isnull && xtype==etSQLESCAPE2;
646         n += i + 1 + needQuote*2;
647         if( n>etBUFSIZE ){
648           bufpt = zExtra = sqlite3Malloc( n );
649           if( bufpt==0 ) return;
650         }else{
651           bufpt = buf;
652         }
653         j = 0;
654         if( needQuote ) bufpt[j++] = q;
655         for(i=0; (ch=escarg[i])!=0; i++){
656           bufpt[j++] = ch;
657           if( ch==q ) bufpt[j++] = ch;
658         }
659         if( needQuote ) bufpt[j++] = q;
660         bufpt[j] = 0;
661         length = j;
662         /* The precision is ignored on %q and %Q */
663         /* if( precision>=0 && precision<length ) length = precision; */
664         break;
665       }
666       case etTOKEN: {
667         Token *pToken = va_arg(ap, Token*);
668         if( pToken ){
669           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
670         }
671         length = width = 0;
672         break;
673       }
674       case etSRCLIST: {
675         SrcList *pSrc = va_arg(ap, SrcList*);
676         int k = va_arg(ap, int);
677         struct SrcList_item *pItem = &pSrc->a[k];
678         assert( k>=0 && k<pSrc->nSrc );
679         if( pItem->zDatabase ){
680           sqlite3StrAccumAppend(pAccum, pItem->zDatabase, -1);
681           sqlite3StrAccumAppend(pAccum, ".", 1);
682         }
683         sqlite3StrAccumAppend(pAccum, pItem->zName, -1);
684         length = width = 0;
685         break;
686       }
687     }/* End switch over the format type */
688     /*
689     ** The text of the conversion is pointed to by "bufpt" and is
690     ** "length" characters long.  The field width is "width".  Do
691     ** the output.
692     */
693     if( !flag_leftjustify ){
694       register int nspace;
695       nspace = width-length;
696       if( nspace>0 ){
697         appendSpace(pAccum, nspace);
698       }
699     }
700     if( length>0 ){
701       sqlite3StrAccumAppend(pAccum, bufpt, length);
702     }
703     if( flag_leftjustify ){
704       register int nspace;
705       nspace = width-length;
706       if( nspace>0 ){
707         appendSpace(pAccum, nspace);
708       }
709     }
710     if( zExtra ){
711       sqlite3_free(zExtra);
712     }
713   }/* End for loop over the format string */
714 } /* End of function */
715 
716 /*
717 ** Append N bytes of text from z to the StrAccum object.
718 */
719 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
720   if( p->tooBig | p->mallocFailed ){
721     return;
722   }
723   if( N<0 ){
724     N = strlen(z);
725   }
726   if( N==0 ){
727     return;
728   }
729   if( p->nChar+N >= p->nAlloc ){
730     char *zNew;
731     if( !p->useMalloc ){
732       p->tooBig = 1;
733       N = p->nAlloc - p->nChar - 1;
734       if( N<=0 ){
735         return;
736       }
737     }else{
738       i64 szNew = p->nChar;
739       szNew += N + 1;
740       if( szNew > p->mxAlloc ){
741         sqlite3StrAccumReset(p);
742         p->tooBig = 1;
743         return;
744       }else{
745         p->nAlloc = szNew;
746       }
747       zNew = sqlite3DbMallocRaw(p->db, p->nAlloc );
748       if( zNew ){
749         memcpy(zNew, p->zText, p->nChar);
750         sqlite3StrAccumReset(p);
751         p->zText = zNew;
752       }else{
753         p->mallocFailed = 1;
754         sqlite3StrAccumReset(p);
755         return;
756       }
757     }
758   }
759   memcpy(&p->zText[p->nChar], z, N);
760   p->nChar += N;
761 }
762 
763 /*
764 ** Finish off a string by making sure it is zero-terminated.
765 ** Return a pointer to the resulting string.  Return a NULL
766 ** pointer if any kind of error was encountered.
767 */
768 char *sqlite3StrAccumFinish(StrAccum *p){
769   if( p->zText ){
770     p->zText[p->nChar] = 0;
771     if( p->useMalloc && p->zText==p->zBase ){
772       p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
773       if( p->zText ){
774         memcpy(p->zText, p->zBase, p->nChar+1);
775       }else{
776         p->mallocFailed = 1;
777       }
778     }
779   }
780   return p->zText;
781 }
782 
783 /*
784 ** Reset an StrAccum string.  Reclaim all malloced memory.
785 */
786 void sqlite3StrAccumReset(StrAccum *p){
787   if( p->zText!=p->zBase ){
788     sqlite3DbFree(p->db, p->zText);
789   }
790   p->zText = 0;
791 }
792 
793 /*
794 ** Initialize a string accumulator
795 */
796 void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
797   p->zText = p->zBase = zBase;
798   p->db = 0;
799   p->nChar = 0;
800   p->nAlloc = n;
801   p->mxAlloc = mx;
802   p->useMalloc = 1;
803   p->tooBig = 0;
804   p->mallocFailed = 0;
805 }
806 
807 /*
808 ** Print into memory obtained from sqliteMalloc().  Use the internal
809 ** %-conversion extensions.
810 */
811 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
812   char *z;
813   char zBase[SQLITE_PRINT_BUF_SIZE];
814   StrAccum acc;
815   sqlite3StrAccumInit(&acc, zBase, sizeof(zBase),
816                       db ? db->aLimit[SQLITE_LIMIT_LENGTH] : SQLITE_MAX_LENGTH);
817   acc.db = db;
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 ** Like sqlite3MPrintf(), but call sqlite3DbFree() on zStr after formatting
841 ** the string and before returnning.  This routine is intended to be used
842 ** to modify an existing string.  For example:
843 **
844 **       x = sqlite3MPrintf(db, x, "prefix %s suffix", x);
845 **
846 */
847 char *sqlite3MAppendf(sqlite3 *db, char *zStr, const char *zFormat, ...){
848   va_list ap;
849   char *z;
850   va_start(ap, zFormat);
851   z = sqlite3VMPrintf(db, zFormat, ap);
852   va_end(ap);
853   sqlite3DbFree(db, zStr);
854   return z;
855 }
856 
857 /*
858 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
859 ** %-conversion extensions.
860 */
861 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
862   char *z;
863   char zBase[SQLITE_PRINT_BUF_SIZE];
864   StrAccum acc;
865 #ifndef SQLITE_OMIT_AUTOINIT
866   if( sqlite3_initialize() ) return 0;
867 #endif
868   sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
869   sqlite3VXPrintf(&acc, 0, zFormat, ap);
870   z = sqlite3StrAccumFinish(&acc);
871   return z;
872 }
873 
874 /*
875 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
876 ** %-conversion extensions.
877 */
878 char *sqlite3_mprintf(const char *zFormat, ...){
879   va_list ap;
880   char *z;
881 #ifndef SQLITE_OMIT_AUTOINIT
882   if( sqlite3_initialize() ) return 0;
883 #endif
884   va_start(ap, zFormat);
885   z = sqlite3_vmprintf(zFormat, ap);
886   va_end(ap);
887   return z;
888 }
889 
890 /*
891 ** sqlite3_snprintf() works like snprintf() except that it ignores the
892 ** current locale settings.  This is important for SQLite because we
893 ** are not able to use a "," as the decimal point in place of "." as
894 ** specified by some locales.
895 */
896 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
897   char *z;
898   va_list ap;
899   StrAccum acc;
900 
901   if( n<=0 ){
902     return zBuf;
903   }
904   sqlite3StrAccumInit(&acc, zBuf, n, 0);
905   acc.useMalloc = 0;
906   va_start(ap,zFormat);
907   sqlite3VXPrintf(&acc, 0, zFormat, ap);
908   va_end(ap);
909   z = sqlite3StrAccumFinish(&acc);
910   return z;
911 }
912 
913 #if defined(SQLITE_DEBUG)
914 /*
915 ** A version of printf() that understands %lld.  Used for debugging.
916 ** The printf() built into some versions of windows does not understand %lld
917 ** and segfaults if you give it a long long int.
918 */
919 void sqlite3DebugPrintf(const char *zFormat, ...){
920   va_list ap;
921   StrAccum acc;
922   char zBuf[500];
923   sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
924   acc.useMalloc = 0;
925   va_start(ap,zFormat);
926   sqlite3VXPrintf(&acc, 0, zFormat, ap);
927   va_end(ap);
928   sqlite3StrAccumFinish(&acc);
929   fprintf(stdout,"%s", zBuf);
930   fflush(stdout);
931 }
932 #endif
933