xref: /sqlite-3.40.0/src/printf.c (revision 70cdf382)
1 /*
2 ** The "printf" code that follows dates from the 1980's.  It is in
3 ** the public domain.
4 **
5 **************************************************************************
6 **
7 ** This file contains code for a set of "printf"-like routines.  These
8 ** routines format strings much like the printf() from the standard C
9 ** library, though the implementation here has enhancements to support
10 ** SQLite.
11 */
12 #include "sqliteInt.h"
13 
14 /*
15 ** Conversion types fall into various categories as defined by the
16 ** following enumeration.
17 */
18 #define etRADIX       0 /* non-decimal integer types.  %x %o */
19 #define etFLOAT       1 /* Floating point.  %f */
20 #define etEXP         2 /* Exponentional notation. %e and %E */
21 #define etGENERIC     3 /* Floating or exponential, depending on exponent. %g */
22 #define etSIZE        4 /* Return number of characters processed so far. %n */
23 #define etSTRING      5 /* Strings. %s */
24 #define etDYNSTRING   6 /* Dynamically allocated strings. %z */
25 #define etPERCENT     7 /* Percent symbol. %% */
26 #define etCHARX       8 /* Characters. %c */
27 /* The rest are extensions, not normally found in printf() */
28 #define etSQLESCAPE   9 /* Strings with '\'' doubled.  %q */
29 #define etSQLESCAPE2 10 /* Strings with '\'' doubled and enclosed in '',
30                           NULL pointers replaced by SQL NULL.  %Q */
31 #define etTOKEN      11 /* a pointer to a Token structure */
32 #define etSRCLIST    12 /* a pointer to a SrcList */
33 #define etPOINTER    13 /* The %p conversion */
34 #define etSQLESCAPE3 14 /* %w -> Strings with '\"' doubled */
35 #define etORDINAL    15 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
36 #define etDECIMAL    16 /* %d or %u, but not %x, %o */
37 
38 #define etINVALID    17 /* Any unrecognized conversion type */
39 
40 
41 /*
42 ** An "etByte" is an 8-bit unsigned value.
43 */
44 typedef unsigned char etByte;
45 
46 /*
47 ** Each builtin conversion character (ex: the 'd' in "%d") is described
48 ** by an instance of the following structure
49 */
50 typedef struct et_info {   /* Information about each format field */
51   char fmttype;            /* The format field code letter */
52   etByte base;             /* The base for radix conversion */
53   etByte flags;            /* One or more of FLAG_ constants below */
54   etByte type;             /* Conversion paradigm */
55   etByte charset;          /* Offset into aDigits[] of the digits string */
56   etByte prefix;           /* Offset into aPrefix[] of the prefix string */
57 } et_info;
58 
59 /*
60 ** Allowed values for et_info.flags
61 */
62 #define FLAG_SIGNED    1     /* True if the value to convert is signed */
63 #define FLAG_STRING    4     /* Allow infinite precision */
64 
65 
66 /*
67 ** The following table is searched linearly, so it is good to put the
68 ** most frequently used conversion types first.
69 */
70 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
71 static const char aPrefix[] = "-x0\000X0";
72 static const et_info fmtinfo[] = {
73   {  'd', 10, 1, etDECIMAL,    0,  0 },
74   {  's',  0, 4, etSTRING,     0,  0 },
75   {  'g',  0, 1, etGENERIC,    30, 0 },
76   {  'z',  0, 4, etDYNSTRING,  0,  0 },
77   {  'q',  0, 4, etSQLESCAPE,  0,  0 },
78   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
79   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
80   {  'c',  0, 0, etCHARX,      0,  0 },
81   {  'o',  8, 0, etRADIX,      0,  2 },
82   {  'u', 10, 0, etDECIMAL,    0,  0 },
83   {  'x', 16, 0, etRADIX,      16, 1 },
84   {  'X', 16, 0, etRADIX,      0,  4 },
85 #ifndef SQLITE_OMIT_FLOATING_POINT
86   {  'f',  0, 1, etFLOAT,      0,  0 },
87   {  'e',  0, 1, etEXP,        30, 0 },
88   {  'E',  0, 1, etEXP,        14, 0 },
89   {  'G',  0, 1, etGENERIC,    14, 0 },
90 #endif
91   {  'i', 10, 1, etDECIMAL,    0,  0 },
92   {  'n',  0, 0, etSIZE,       0,  0 },
93   {  '%',  0, 0, etPERCENT,    0,  0 },
94   {  'p', 16, 0, etPOINTER,    0,  1 },
95 
96   /* All the rest are undocumented and are for internal use only */
97   {  'T',  0, 0, etTOKEN,      0,  0 },
98   {  'S',  0, 0, etSRCLIST,    0,  0 },
99   {  'r', 10, 1, etORDINAL,    0,  0 },
100 };
101 
102 /*
103 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
104 ** conversions will work.
105 */
106 #ifndef SQLITE_OMIT_FLOATING_POINT
107 /*
108 ** "*val" is a double such that 0.1 <= *val < 10.0
109 ** Return the ascii code for the leading digit of *val, then
110 ** multiply "*val" by 10.0 to renormalize.
111 **
112 ** Example:
113 **     input:     *val = 3.14159
114 **     output:    *val = 1.4159    function return = '3'
115 **
116 ** The counter *cnt is incremented each time.  After counter exceeds
117 ** 16 (the number of significant digits in a 64-bit float) '0' is
118 ** always returned.
119 */
120 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
121   int digit;
122   LONGDOUBLE_TYPE d;
123   if( (*cnt)<=0 ) return '0';
124   (*cnt)--;
125   digit = (int)*val;
126   d = digit;
127   digit += '0';
128   *val = (*val - d)*10.0;
129   return (char)digit;
130 }
131 #endif /* SQLITE_OMIT_FLOATING_POINT */
132 
133 /*
134 ** Set the StrAccum object to an error mode.
135 */
136 static void setStrAccumError(StrAccum *p, u8 eError){
137   assert( eError==STRACCUM_NOMEM || eError==STRACCUM_TOOBIG );
138   p->accError = eError;
139   p->nAlloc = 0;
140 }
141 
142 /*
143 ** Extra argument values from a PrintfArguments object
144 */
145 static sqlite3_int64 getIntArg(PrintfArguments *p){
146   if( p->nArg<=p->nUsed ) return 0;
147   return sqlite3_value_int64(p->apArg[p->nUsed++]);
148 }
149 static double getDoubleArg(PrintfArguments *p){
150   if( p->nArg<=p->nUsed ) return 0.0;
151   return sqlite3_value_double(p->apArg[p->nUsed++]);
152 }
153 static char *getTextArg(PrintfArguments *p){
154   if( p->nArg<=p->nUsed ) return 0;
155   return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
156 }
157 
158 
159 /*
160 ** On machines with a small stack size, you can redefine the
161 ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
162 */
163 #ifndef SQLITE_PRINT_BUF_SIZE
164 # define SQLITE_PRINT_BUF_SIZE 70
165 #endif
166 #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */
167 
168 /*
169 ** Render a string given by "fmt" into the StrAccum object.
170 */
171 void sqlite3VXPrintf(
172   StrAccum *pAccum,          /* Accumulate results here */
173   const char *fmt,           /* Format string */
174   va_list ap                 /* arguments */
175 ){
176   int c;                     /* Next character in the format string */
177   char *bufpt;               /* Pointer to the conversion buffer */
178   int precision;             /* Precision of the current field */
179   int length;                /* Length of the field */
180   int idx;                   /* A general purpose loop counter */
181   int width;                 /* Width of the current field */
182   etByte flag_leftjustify;   /* True if "-" flag is present */
183   etByte flag_prefix;        /* '+' or ' ' or 0 for prefix */
184   etByte flag_alternateform; /* True if "#" flag is present */
185   etByte flag_altform2;      /* True if "!" flag is present */
186   etByte flag_zeropad;       /* True if field width constant starts with zero */
187   etByte flag_long;          /* 1 for the "l" flag, 2 for "ll", 0 by default */
188   etByte done;               /* Loop termination flag */
189   etByte cThousand;          /* Thousands separator for %d and %u */
190   etByte xtype = etINVALID;  /* Conversion paradigm */
191   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
192   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
193   sqlite_uint64 longvalue;   /* Value for integer types */
194   LONGDOUBLE_TYPE realvalue; /* Value for real types */
195   const et_info *infop;      /* Pointer to the appropriate info structure */
196   char *zOut;                /* Rendering buffer */
197   int nOut;                  /* Size of the rendering buffer */
198   char *zExtra = 0;          /* Malloced memory used by some conversion */
199 #ifndef SQLITE_OMIT_FLOATING_POINT
200   int  exp, e2;              /* exponent of real numbers */
201   int nsd;                   /* Number of significant digits returned */
202   double rounder;            /* Used for rounding floating point values */
203   etByte flag_dp;            /* True if decimal point should be shown */
204   etByte flag_rtz;           /* True if trailing zeros should be removed */
205 #endif
206   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
207   char buf[etBUFSIZE];       /* Conversion buffer */
208 
209   bufpt = 0;
210   if( (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC)!=0 ){
211     pArgList = va_arg(ap, PrintfArguments*);
212     bArgList = 1;
213   }else{
214     bArgList = 0;
215   }
216   for(; (c=(*fmt))!=0; ++fmt){
217     if( c!='%' ){
218       bufpt = (char *)fmt;
219 #if HAVE_STRCHRNUL
220       fmt = strchrnul(fmt, '%');
221 #else
222       do{ fmt++; }while( *fmt && *fmt != '%' );
223 #endif
224       sqlite3StrAccumAppend(pAccum, bufpt, (int)(fmt - bufpt));
225       if( *fmt==0 ) break;
226     }
227     if( (c=(*++fmt))==0 ){
228       sqlite3StrAccumAppend(pAccum, "%", 1);
229       break;
230     }
231     /* Find out what flags are present */
232     flag_leftjustify = flag_prefix = cThousand =
233      flag_alternateform = flag_altform2 = flag_zeropad = 0;
234     done = 0;
235     do{
236       switch( c ){
237         case '-':   flag_leftjustify = 1;     break;
238         case '+':   flag_prefix = '+';        break;
239         case ' ':   flag_prefix = ' ';        break;
240         case '#':   flag_alternateform = 1;   break;
241         case '!':   flag_altform2 = 1;        break;
242         case '0':   flag_zeropad = 1;         break;
243         case ',':   cThousand = ',';          break;
244         default:    done = 1;                 break;
245       }
246     }while( !done && (c=(*++fmt))!=0 );
247     /* Get the field width */
248     if( c=='*' ){
249       if( bArgList ){
250         width = (int)getIntArg(pArgList);
251       }else{
252         width = va_arg(ap,int);
253       }
254       if( width<0 ){
255         flag_leftjustify = 1;
256         width = width >= -2147483647 ? -width : 0;
257       }
258       c = *++fmt;
259     }else{
260       unsigned wx = 0;
261       while( c>='0' && c<='9' ){
262         wx = wx*10 + c - '0';
263         c = *++fmt;
264       }
265       testcase( wx>0x7fffffff );
266       width = wx & 0x7fffffff;
267     }
268     assert( width>=0 );
269 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
270     if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
271       width = SQLITE_PRINTF_PRECISION_LIMIT;
272     }
273 #endif
274 
275     /* Get the precision */
276     if( c=='.' ){
277       c = *++fmt;
278       if( c=='*' ){
279         if( bArgList ){
280           precision = (int)getIntArg(pArgList);
281         }else{
282           precision = va_arg(ap,int);
283         }
284         c = *++fmt;
285         if( precision<0 ){
286           precision = precision >= -2147483647 ? -precision : -1;
287         }
288       }else{
289         unsigned px = 0;
290         while( c>='0' && c<='9' ){
291           px = px*10 + c - '0';
292           c = *++fmt;
293         }
294         testcase( px>0x7fffffff );
295         precision = px & 0x7fffffff;
296       }
297     }else{
298       precision = -1;
299     }
300     assert( precision>=(-1) );
301 #ifdef SQLITE_PRINTF_PRECISION_LIMIT
302     if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
303       precision = SQLITE_PRINTF_PRECISION_LIMIT;
304     }
305 #endif
306 
307 
308     /* Get the conversion type modifier */
309     if( c=='l' ){
310       flag_long = 1;
311       c = *++fmt;
312       if( c=='l' ){
313         flag_long = 2;
314         c = *++fmt;
315       }
316     }else{
317       flag_long = 0;
318     }
319     /* Fetch the info entry for the field */
320     infop = &fmtinfo[0];
321     xtype = etINVALID;
322     for(idx=0; idx<ArraySize(fmtinfo); idx++){
323       if( c==fmtinfo[idx].fmttype ){
324         infop = &fmtinfo[idx];
325         xtype = infop->type;
326         break;
327       }
328     }
329 
330     /*
331     ** At this point, variables are initialized as follows:
332     **
333     **   flag_alternateform          TRUE if a '#' is present.
334     **   flag_altform2               TRUE if a '!' is present.
335     **   flag_prefix                 '+' or ' ' or zero
336     **   flag_leftjustify            TRUE if a '-' is present or if the
337     **                               field width was negative.
338     **   flag_zeropad                TRUE if the width began with 0.
339     **   flag_long                   1 for "l", 2 for "ll"
340     **   width                       The specified field width.  This is
341     **                               always non-negative.  Zero is the default.
342     **   precision                   The specified precision.  The default
343     **                               is -1.
344     **   xtype                       The class of the conversion.
345     **   infop                       Pointer to the appropriate info struct.
346     */
347     switch( xtype ){
348       case etPOINTER:
349         flag_long = sizeof(char*)==sizeof(i64) ? 2 :
350                      sizeof(char*)==sizeof(long int) ? 1 : 0;
351         /* Fall through into the next case */
352       case etORDINAL:
353       case etRADIX:
354         cThousand = 0;
355         /* Fall through into the next case */
356       case etDECIMAL:
357         if( infop->flags & FLAG_SIGNED ){
358           i64 v;
359           if( bArgList ){
360             v = getIntArg(pArgList);
361           }else if( flag_long ){
362             if( flag_long==2 ){
363               v = va_arg(ap,i64) ;
364             }else{
365               v = va_arg(ap,long int);
366             }
367           }else{
368             v = va_arg(ap,int);
369           }
370           if( v<0 ){
371             if( v==SMALLEST_INT64 ){
372               longvalue = ((u64)1)<<63;
373             }else{
374               longvalue = -v;
375             }
376             prefix = '-';
377           }else{
378             longvalue = v;
379             prefix = flag_prefix;
380           }
381         }else{
382           if( bArgList ){
383             longvalue = (u64)getIntArg(pArgList);
384           }else if( flag_long ){
385             if( flag_long==2 ){
386               longvalue = va_arg(ap,u64);
387             }else{
388               longvalue = va_arg(ap,unsigned long int);
389             }
390           }else{
391             longvalue = va_arg(ap,unsigned int);
392           }
393           prefix = 0;
394         }
395         if( longvalue==0 ) flag_alternateform = 0;
396         if( flag_zeropad && precision<width-(prefix!=0) ){
397           precision = width-(prefix!=0);
398         }
399         if( precision<etBUFSIZE-10-etBUFSIZE/3 ){
400           nOut = etBUFSIZE;
401           zOut = buf;
402         }else{
403           nOut = precision + 10 + precision/3;
404           zOut = zExtra = sqlite3Malloc( nOut );
405           if( zOut==0 ){
406             setStrAccumError(pAccum, STRACCUM_NOMEM);
407             return;
408           }
409         }
410         bufpt = &zOut[nOut-1];
411         if( xtype==etORDINAL ){
412           static const char zOrd[] = "thstndrd";
413           int x = (int)(longvalue % 10);
414           if( x>=4 || (longvalue/10)%10==1 ){
415             x = 0;
416           }
417           *(--bufpt) = zOrd[x*2+1];
418           *(--bufpt) = zOrd[x*2];
419         }
420         {
421           const char *cset = &aDigits[infop->charset];
422           u8 base = infop->base;
423           do{                                           /* Convert to ascii */
424             *(--bufpt) = cset[longvalue%base];
425             longvalue = longvalue/base;
426           }while( longvalue>0 );
427         }
428         length = (int)(&zOut[nOut-1]-bufpt);
429         while( precision>length ){
430           *(--bufpt) = '0';                             /* Zero pad */
431           length++;
432         }
433         if( cThousand ){
434           int nn = (length - 1)/3;  /* Number of "," to insert */
435           int ix = (length - 1)%3 + 1;
436           bufpt -= nn;
437           for(idx=0; nn>0; idx++){
438             bufpt[idx] = bufpt[idx+nn];
439             ix--;
440             if( ix==0 ){
441               bufpt[++idx] = cThousand;
442               nn--;
443               ix = 3;
444             }
445           }
446         }
447         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
448         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
449           const char *pre;
450           char x;
451           pre = &aPrefix[infop->prefix];
452           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;
453         }
454         length = (int)(&zOut[nOut-1]-bufpt);
455         break;
456       case etFLOAT:
457       case etEXP:
458       case etGENERIC:
459         if( bArgList ){
460           realvalue = getDoubleArg(pArgList);
461         }else{
462           realvalue = va_arg(ap,double);
463         }
464 #ifdef SQLITE_OMIT_FLOATING_POINT
465         length = 0;
466 #else
467         if( precision<0 ) precision = 6;         /* Set default precision */
468         if( realvalue<0.0 ){
469           realvalue = -realvalue;
470           prefix = '-';
471         }else{
472           prefix = flag_prefix;
473         }
474         if( xtype==etGENERIC && precision>0 ) precision--;
475         testcase( precision>0xfff );
476         for(idx=precision&0xfff, rounder=0.5; idx>0; idx--, rounder*=0.1){}
477         if( xtype==etFLOAT ) realvalue += rounder;
478         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
479         exp = 0;
480         if( sqlite3IsNaN((double)realvalue) ){
481           bufpt = "NaN";
482           length = 3;
483           break;
484         }
485         if( realvalue>0.0 ){
486           LONGDOUBLE_TYPE scale = 1.0;
487           while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
488           while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }
489           while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
490           realvalue /= scale;
491           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
492           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
493           if( exp>350 ){
494             bufpt = buf;
495             buf[0] = prefix;
496             memcpy(buf+(prefix!=0),"Inf",4);
497             length = 3+(prefix!=0);
498             break;
499           }
500         }
501         bufpt = buf;
502         /*
503         ** If the field type is etGENERIC, then convert to either etEXP
504         ** or etFLOAT, as appropriate.
505         */
506         if( xtype!=etFLOAT ){
507           realvalue += rounder;
508           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
509         }
510         if( xtype==etGENERIC ){
511           flag_rtz = !flag_alternateform;
512           if( exp<-4 || exp>precision ){
513             xtype = etEXP;
514           }else{
515             precision = precision - exp;
516             xtype = etFLOAT;
517           }
518         }else{
519           flag_rtz = flag_altform2;
520         }
521         if( xtype==etEXP ){
522           e2 = 0;
523         }else{
524           e2 = exp;
525         }
526         if( MAX(e2,0)+(i64)precision+(i64)width > etBUFSIZE - 15 ){
527           bufpt = zExtra
528               = sqlite3Malloc( MAX(e2,0)+(i64)precision+(i64)width+15 );
529           if( bufpt==0 ){
530             setStrAccumError(pAccum, STRACCUM_NOMEM);
531             return;
532           }
533         }
534         zOut = bufpt;
535         nsd = 16 + flag_altform2*10;
536         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
537         /* The sign in front of the number */
538         if( prefix ){
539           *(bufpt++) = prefix;
540         }
541         /* Digits prior to the decimal point */
542         if( e2<0 ){
543           *(bufpt++) = '0';
544         }else{
545           for(; e2>=0; e2--){
546             *(bufpt++) = et_getdigit(&realvalue,&nsd);
547           }
548         }
549         /* The decimal point */
550         if( flag_dp ){
551           *(bufpt++) = '.';
552         }
553         /* "0" digits after the decimal point but before the first
554         ** significant digit of the number */
555         for(e2++; e2<0; precision--, e2++){
556           assert( precision>0 );
557           *(bufpt++) = '0';
558         }
559         /* Significant digits after the decimal point */
560         while( (precision--)>0 ){
561           *(bufpt++) = et_getdigit(&realvalue,&nsd);
562         }
563         /* Remove trailing zeros and the "." if no digits follow the "." */
564         if( flag_rtz && flag_dp ){
565           while( bufpt[-1]=='0' ) *(--bufpt) = 0;
566           assert( bufpt>zOut );
567           if( bufpt[-1]=='.' ){
568             if( flag_altform2 ){
569               *(bufpt++) = '0';
570             }else{
571               *(--bufpt) = 0;
572             }
573           }
574         }
575         /* Add the "eNNN" suffix */
576         if( xtype==etEXP ){
577           *(bufpt++) = aDigits[infop->charset];
578           if( exp<0 ){
579             *(bufpt++) = '-'; exp = -exp;
580           }else{
581             *(bufpt++) = '+';
582           }
583           if( exp>=100 ){
584             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */
585             exp %= 100;
586           }
587           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */
588           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */
589         }
590         *bufpt = 0;
591 
592         /* The converted number is in buf[] and zero terminated. Output it.
593         ** Note that the number is in the usual order, not reversed as with
594         ** integer conversions. */
595         length = (int)(bufpt-zOut);
596         bufpt = zOut;
597 
598         /* Special case:  Add leading zeros if the flag_zeropad flag is
599         ** set and we are not left justified */
600         if( flag_zeropad && !flag_leftjustify && length < width){
601           int i;
602           int nPad = width - length;
603           for(i=width; i>=nPad; i--){
604             bufpt[i] = bufpt[i-nPad];
605           }
606           i = prefix!=0;
607           while( nPad-- ) bufpt[i++] = '0';
608           length = width;
609         }
610 #endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */
611         break;
612       case etSIZE:
613         if( !bArgList ){
614           *(va_arg(ap,int*)) = pAccum->nChar;
615         }
616         length = width = 0;
617         break;
618       case etPERCENT:
619         buf[0] = '%';
620         bufpt = buf;
621         length = 1;
622         break;
623       case etCHARX:
624         if( bArgList ){
625           bufpt = getTextArg(pArgList);
626           c = bufpt ? bufpt[0] : 0;
627         }else{
628           c = va_arg(ap,int);
629         }
630         if( precision>1 ){
631           width -= precision-1;
632           if( width>1 && !flag_leftjustify ){
633             sqlite3AppendChar(pAccum, width-1, ' ');
634             width = 0;
635           }
636           sqlite3AppendChar(pAccum, precision-1, c);
637         }
638         length = 1;
639         buf[0] = c;
640         bufpt = buf;
641         break;
642       case etSTRING:
643       case etDYNSTRING:
644         if( bArgList ){
645           bufpt = getTextArg(pArgList);
646           xtype = etSTRING;
647         }else{
648           bufpt = va_arg(ap,char*);
649         }
650         if( bufpt==0 ){
651           bufpt = "";
652         }else if( xtype==etDYNSTRING ){
653           zExtra = bufpt;
654         }
655         if( precision>=0 ){
656           for(length=0; length<precision && bufpt[length]; length++){}
657         }else{
658           length = sqlite3Strlen30(bufpt);
659         }
660         break;
661       case etSQLESCAPE:           /* Escape ' characters */
662       case etSQLESCAPE2:          /* Escape ' and enclose in '...' */
663       case etSQLESCAPE3: {        /* Escape " characters */
664         int i, j, k, n, isnull;
665         int needQuote;
666         char ch;
667         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
668         char *escarg;
669 
670         if( bArgList ){
671           escarg = getTextArg(pArgList);
672         }else{
673           escarg = va_arg(ap,char*);
674         }
675         isnull = escarg==0;
676         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
677         k = precision;
678         for(i=n=0; k!=0 && (ch=escarg[i])!=0; i++, k--){
679           if( ch==q )  n++;
680         }
681         needQuote = !isnull && xtype==etSQLESCAPE2;
682         n += i + 3;
683         if( n>etBUFSIZE ){
684           bufpt = zExtra = sqlite3Malloc( n );
685           if( bufpt==0 ){
686             setStrAccumError(pAccum, STRACCUM_NOMEM);
687             return;
688           }
689         }else{
690           bufpt = buf;
691         }
692         j = 0;
693         if( needQuote ) bufpt[j++] = q;
694         k = i;
695         for(i=0; i<k; i++){
696           bufpt[j++] = ch = escarg[i];
697           if( ch==q ) bufpt[j++] = ch;
698         }
699         if( needQuote ) bufpt[j++] = q;
700         bufpt[j] = 0;
701         length = j;
702         /* The precision in %q and %Q means how many input characters to
703         ** consume, not the length of the output...
704         ** if( precision>=0 && precision<length ) length = precision; */
705         break;
706       }
707       case etTOKEN: {
708         Token *pToken;
709         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
710         pToken = va_arg(ap, Token*);
711         assert( bArgList==0 );
712         if( pToken && pToken->n ){
713           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
714         }
715         length = width = 0;
716         break;
717       }
718       case etSRCLIST: {
719         SrcList *pSrc;
720         int k;
721         struct SrcList_item *pItem;
722         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
723         pSrc = va_arg(ap, SrcList*);
724         k = va_arg(ap, int);
725         pItem = &pSrc->a[k];
726         assert( bArgList==0 );
727         assert( k>=0 && k<pSrc->nSrc );
728         if( pItem->zDatabase ){
729           sqlite3StrAccumAppendAll(pAccum, pItem->zDatabase);
730           sqlite3StrAccumAppend(pAccum, ".", 1);
731         }
732         sqlite3StrAccumAppendAll(pAccum, pItem->zName);
733         length = width = 0;
734         break;
735       }
736       default: {
737         assert( xtype==etINVALID );
738         return;
739       }
740     }/* End switch over the format type */
741     /*
742     ** The text of the conversion is pointed to by "bufpt" and is
743     ** "length" characters long.  The field width is "width".  Do
744     ** the output.
745     */
746     width -= length;
747     if( width>0 ){
748       if( !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
749       sqlite3StrAccumAppend(pAccum, bufpt, length);
750       if( flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
751     }else{
752       sqlite3StrAccumAppend(pAccum, bufpt, length);
753     }
754 
755     if( zExtra ){
756       sqlite3DbFree(pAccum->db, zExtra);
757       zExtra = 0;
758     }
759   }/* End for loop over the format string */
760 } /* End of function */
761 
762 /*
763 ** Enlarge the memory allocation on a StrAccum object so that it is
764 ** able to accept at least N more bytes of text.
765 **
766 ** Return the number of bytes of text that StrAccum is able to accept
767 ** after the attempted enlargement.  The value returned might be zero.
768 */
769 static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
770   char *zNew;
771   assert( p->nChar+(i64)N >= p->nAlloc ); /* Only called if really needed */
772   if( p->accError ){
773     testcase(p->accError==STRACCUM_TOOBIG);
774     testcase(p->accError==STRACCUM_NOMEM);
775     return 0;
776   }
777   if( p->mxAlloc==0 ){
778     N = p->nAlloc - p->nChar - 1;
779     setStrAccumError(p, STRACCUM_TOOBIG);
780     return N;
781   }else{
782     char *zOld = isMalloced(p) ? p->zText : 0;
783     i64 szNew = p->nChar;
784     assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
785     szNew += N + 1;
786     if( szNew+p->nChar<=p->mxAlloc ){
787       /* Force exponential buffer size growth as long as it does not overflow,
788       ** to avoid having to call this routine too often */
789       szNew += p->nChar;
790     }
791     if( szNew > p->mxAlloc ){
792       sqlite3StrAccumReset(p);
793       setStrAccumError(p, STRACCUM_TOOBIG);
794       return 0;
795     }else{
796       p->nAlloc = (int)szNew;
797     }
798     if( p->db ){
799       zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
800     }else{
801       zNew = sqlite3_realloc64(zOld, p->nAlloc);
802     }
803     if( zNew ){
804       assert( p->zText!=0 || p->nChar==0 );
805       if( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
806       p->zText = zNew;
807       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
808       p->printfFlags |= SQLITE_PRINTF_MALLOCED;
809     }else{
810       sqlite3StrAccumReset(p);
811       setStrAccumError(p, STRACCUM_NOMEM);
812       return 0;
813     }
814   }
815   return N;
816 }
817 
818 /*
819 ** Append N copies of character c to the given string buffer.
820 */
821 void sqlite3AppendChar(StrAccum *p, int N, char c){
822   testcase( p->nChar + (i64)N > 0x7fffffff );
823   if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
824     return;
825   }
826   assert( (p->zText==p->zBase)==!isMalloced(p) );
827   while( (N--)>0 ) p->zText[p->nChar++] = c;
828 }
829 
830 /*
831 ** The StrAccum "p" is not large enough to accept N new bytes of z[].
832 ** So enlarge if first, then do the append.
833 **
834 ** This is a helper routine to sqlite3StrAccumAppend() that does special-case
835 ** work (enlarging the buffer) using tail recursion, so that the
836 ** sqlite3StrAccumAppend() routine can use fast calling semantics.
837 */
838 static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
839   N = sqlite3StrAccumEnlarge(p, N);
840   if( N>0 ){
841     memcpy(&p->zText[p->nChar], z, N);
842     p->nChar += N;
843   }
844   assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
845 }
846 
847 /*
848 ** Append N bytes of text from z to the StrAccum object.  Increase the
849 ** size of the memory allocation for StrAccum if necessary.
850 */
851 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
852   assert( z!=0 || N==0 );
853   assert( p->zText!=0 || p->nChar==0 || p->accError );
854   assert( N>=0 );
855   assert( p->accError==0 || p->nAlloc==0 );
856   if( p->nChar+N >= p->nAlloc ){
857     enlargeAndAppend(p,z,N);
858   }else if( N ){
859     assert( p->zText );
860     p->nChar += N;
861     memcpy(&p->zText[p->nChar-N], z, N);
862   }
863 }
864 
865 /*
866 ** Append the complete text of zero-terminated string z[] to the p string.
867 */
868 void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
869   sqlite3StrAccumAppend(p, z, sqlite3Strlen30(z));
870 }
871 
872 
873 /*
874 ** Finish off a string by making sure it is zero-terminated.
875 ** Return a pointer to the resulting string.  Return a NULL
876 ** pointer if any kind of error was encountered.
877 */
878 static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){
879   assert( p->mxAlloc>0 && !isMalloced(p) );
880   p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
881   if( p->zText ){
882     memcpy(p->zText, p->zBase, p->nChar+1);
883     p->printfFlags |= SQLITE_PRINTF_MALLOCED;
884   }else{
885     setStrAccumError(p, STRACCUM_NOMEM);
886   }
887   return p->zText;
888 }
889 char *sqlite3StrAccumFinish(StrAccum *p){
890   if( p->zText ){
891     assert( (p->zText==p->zBase)==!isMalloced(p) );
892     p->zText[p->nChar] = 0;
893     if( p->mxAlloc>0 && !isMalloced(p) ){
894       return strAccumFinishRealloc(p);
895     }
896   }
897   return p->zText;
898 }
899 
900 /*
901 ** Reset an StrAccum string.  Reclaim all malloced memory.
902 */
903 void sqlite3StrAccumReset(StrAccum *p){
904   assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
905   if( isMalloced(p) ){
906     sqlite3DbFree(p->db, p->zText);
907     p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;
908   }
909   p->zText = 0;
910 }
911 
912 /*
913 ** Initialize a string accumulator.
914 **
915 ** p:     The accumulator to be initialized.
916 ** db:    Pointer to a database connection.  May be NULL.  Lookaside
917 **        memory is used if not NULL. db->mallocFailed is set appropriately
918 **        when not NULL.
919 ** zBase: An initial buffer.  May be NULL in which case the initial buffer
920 **        is malloced.
921 ** n:     Size of zBase in bytes.  If total space requirements never exceed
922 **        n then no memory allocations ever occur.
923 ** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
924 **        allocations will ever occur.
925 */
926 void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
927   p->zText = p->zBase = zBase;
928   p->db = db;
929   p->nChar = 0;
930   p->nAlloc = n;
931   p->mxAlloc = mx;
932   p->accError = 0;
933   p->printfFlags = 0;
934 }
935 
936 /*
937 ** Print into memory obtained from sqliteMalloc().  Use the internal
938 ** %-conversion extensions.
939 */
940 char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
941   char *z;
942   char zBase[SQLITE_PRINT_BUF_SIZE];
943   StrAccum acc;
944   assert( db!=0 );
945   sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
946                       db->aLimit[SQLITE_LIMIT_LENGTH]);
947   acc.printfFlags = SQLITE_PRINTF_INTERNAL;
948   sqlite3VXPrintf(&acc, zFormat, ap);
949   z = sqlite3StrAccumFinish(&acc);
950   if( acc.accError==STRACCUM_NOMEM ){
951     sqlite3OomFault(db);
952   }
953   return z;
954 }
955 
956 /*
957 ** Print into memory obtained from sqliteMalloc().  Use the internal
958 ** %-conversion extensions.
959 */
960 char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
961   va_list ap;
962   char *z;
963   va_start(ap, zFormat);
964   z = sqlite3VMPrintf(db, zFormat, ap);
965   va_end(ap);
966   return z;
967 }
968 
969 /*
970 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
971 ** %-conversion extensions.
972 */
973 char *sqlite3_vmprintf(const char *zFormat, va_list ap){
974   char *z;
975   char zBase[SQLITE_PRINT_BUF_SIZE];
976   StrAccum acc;
977 
978 #ifdef SQLITE_ENABLE_API_ARMOR
979   if( zFormat==0 ){
980     (void)SQLITE_MISUSE_BKPT;
981     return 0;
982   }
983 #endif
984 #ifndef SQLITE_OMIT_AUTOINIT
985   if( sqlite3_initialize() ) return 0;
986 #endif
987   sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
988   sqlite3VXPrintf(&acc, zFormat, ap);
989   z = sqlite3StrAccumFinish(&acc);
990   return z;
991 }
992 
993 /*
994 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
995 ** %-conversion extensions.
996 */
997 char *sqlite3_mprintf(const char *zFormat, ...){
998   va_list ap;
999   char *z;
1000 #ifndef SQLITE_OMIT_AUTOINIT
1001   if( sqlite3_initialize() ) return 0;
1002 #endif
1003   va_start(ap, zFormat);
1004   z = sqlite3_vmprintf(zFormat, ap);
1005   va_end(ap);
1006   return z;
1007 }
1008 
1009 /*
1010 ** sqlite3_snprintf() works like snprintf() except that it ignores the
1011 ** current locale settings.  This is important for SQLite because we
1012 ** are not able to use a "," as the decimal point in place of "." as
1013 ** specified by some locales.
1014 **
1015 ** Oops:  The first two arguments of sqlite3_snprintf() are backwards
1016 ** from the snprintf() standard.  Unfortunately, it is too late to change
1017 ** this without breaking compatibility, so we just have to live with the
1018 ** mistake.
1019 **
1020 ** sqlite3_vsnprintf() is the varargs version.
1021 */
1022 char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
1023   StrAccum acc;
1024   if( n<=0 ) return zBuf;
1025 #ifdef SQLITE_ENABLE_API_ARMOR
1026   if( zBuf==0 || zFormat==0 ) {
1027     (void)SQLITE_MISUSE_BKPT;
1028     if( zBuf ) zBuf[0] = 0;
1029     return zBuf;
1030   }
1031 #endif
1032   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
1033   sqlite3VXPrintf(&acc, zFormat, ap);
1034   zBuf[acc.nChar] = 0;
1035   return zBuf;
1036 }
1037 char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
1038   char *z;
1039   va_list ap;
1040   va_start(ap,zFormat);
1041   z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);
1042   va_end(ap);
1043   return z;
1044 }
1045 
1046 /*
1047 ** This is the routine that actually formats the sqlite3_log() message.
1048 ** We house it in a separate routine from sqlite3_log() to avoid using
1049 ** stack space on small-stack systems when logging is disabled.
1050 **
1051 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
1052 ** allocate memory because it might be called while the memory allocator
1053 ** mutex is held.
1054 **
1055 ** sqlite3VXPrintf() might ask for *temporary* memory allocations for
1056 ** certain format characters (%q) or for very large precisions or widths.
1057 ** Care must be taken that any sqlite3_log() calls that occur while the
1058 ** memory mutex is held do not use these mechanisms.
1059 */
1060 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
1061   StrAccum acc;                          /* String accumulator */
1062   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
1063 
1064   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
1065   sqlite3VXPrintf(&acc, zFormat, ap);
1066   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
1067                            sqlite3StrAccumFinish(&acc));
1068 }
1069 
1070 /*
1071 ** Format and write a message to the log if logging is enabled.
1072 */
1073 void sqlite3_log(int iErrCode, const char *zFormat, ...){
1074   va_list ap;                             /* Vararg list */
1075   if( sqlite3GlobalConfig.xLog ){
1076     va_start(ap, zFormat);
1077     renderLogMsg(iErrCode, zFormat, ap);
1078     va_end(ap);
1079   }
1080 }
1081 
1082 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
1083 /*
1084 ** A version of printf() that understands %lld.  Used for debugging.
1085 ** The printf() built into some versions of windows does not understand %lld
1086 ** and segfaults if you give it a long long int.
1087 */
1088 void sqlite3DebugPrintf(const char *zFormat, ...){
1089   va_list ap;
1090   StrAccum acc;
1091   char zBuf[500];
1092   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
1093   va_start(ap,zFormat);
1094   sqlite3VXPrintf(&acc, zFormat, ap);
1095   va_end(ap);
1096   sqlite3StrAccumFinish(&acc);
1097   fprintf(stdout,"%s", zBuf);
1098   fflush(stdout);
1099 }
1100 #endif
1101 
1102 
1103 /*
1104 ** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
1105 ** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
1106 */
1107 void sqlite3XPrintf(StrAccum *p, const char *zFormat, ...){
1108   va_list ap;
1109   va_start(ap,zFormat);
1110   sqlite3VXPrintf(p, zFormat, ap);
1111   va_end(ap);
1112 }
1113