xref: /sqlite-3.40.0/src/tokenize.c (revision 3c648882)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** An tokenizer for SQL
13 **
14 ** This file contains C code that splits an SQL input string up into
15 ** individual tokens and sends those tokens one-by-one over to the
16 ** parser for analysis.
17 */
18 #include "sqliteInt.h"
19 #include <stdlib.h>
20 
21 /* Character classes for tokenizing
22 **
23 ** In the sqlite3GetToken() function, a switch() on aiClass[c] is implemented
24 ** using a lookup table, whereas a switch() directly on c uses a binary search.
25 ** The lookup table is much faster.  To maximize speed, and to ensure that
26 ** a lookup table is used, all of the classes need to be small integers and
27 ** all of them need to be used within the switch.
28 */
29 #define CC_X          0    /* The letter 'x', or start of BLOB literal */
30 #define CC_KYWD0      1    /* First letter of a keyword */
31 #define CC_KYWD       2    /* Alphabetics or '_'.  Usable in a keyword */
32 #define CC_DIGIT      3    /* Digits */
33 #define CC_DOLLAR     4    /* '$' */
34 #define CC_VARALPHA   5    /* '@', '#', ':'.  Alphabetic SQL variables */
35 #define CC_VARNUM     6    /* '?'.  Numeric SQL variables */
36 #define CC_SPACE      7    /* Space characters */
37 #define CC_QUOTE      8    /* '"', '\'', or '`'.  String literals, quoted ids */
38 #define CC_QUOTE2     9    /* '['.   [...] style quoted ids */
39 #define CC_PIPE      10    /* '|'.   Bitwise OR or concatenate */
40 #define CC_MINUS     11    /* '-'.  Minus or SQL-style comment */
41 #define CC_LT        12    /* '<'.  Part of < or <= or <> */
42 #define CC_GT        13    /* '>'.  Part of > or >= */
43 #define CC_EQ        14    /* '='.  Part of = or == */
44 #define CC_BANG      15    /* '!'.  Part of != */
45 #define CC_SLASH     16    /* '/'.  / or c-style comment */
46 #define CC_LP        17    /* '(' */
47 #define CC_RP        18    /* ')' */
48 #define CC_SEMI      19    /* ';' */
49 #define CC_PLUS      20    /* '+' */
50 #define CC_STAR      21    /* '*' */
51 #define CC_PERCENT   22    /* '%' */
52 #define CC_COMMA     23    /* ',' */
53 #define CC_AND       24    /* '&' */
54 #define CC_TILDA     25    /* '~' */
55 #define CC_DOT       26    /* '.' */
56 #define CC_ID        27    /* unicode characters usable in IDs */
57 #define CC_ILLEGAL   28    /* Illegal character */
58 #define CC_NUL       29    /* 0x00 */
59 #define CC_BOM       30    /* First byte of UTF8 BOM:  0xEF 0xBB 0xBF */
60 
61 static const unsigned char aiClass[] = {
62 #ifdef SQLITE_ASCII
63 /*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */
64 /* 0x */   29, 28, 28, 28, 28, 28, 28, 28, 28,  7,  7, 28,  7,  7, 28, 28,
65 /* 1x */   28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
66 /* 2x */    7, 15,  8,  5,  4, 22, 24,  8, 17, 18, 21, 20, 23, 11, 26, 16,
67 /* 3x */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  5, 19, 12, 14, 13,  6,
68 /* 4x */    5,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
69 /* 5x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  2,  2,  9, 28, 28, 28,  2,
70 /* 6x */    8,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
71 /* 7x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  2,  2, 28, 10, 28, 25, 28,
72 /* 8x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
73 /* 9x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
74 /* Ax */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
75 /* Bx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
76 /* Cx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
77 /* Dx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
78 /* Ex */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 30,
79 /* Fx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27
80 #endif
81 #ifdef SQLITE_EBCDIC
82 /*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */
83 /* 0x */   29, 28, 28, 28, 28,  7, 28, 28, 28, 28, 28, 28,  7,  7, 28, 28,
84 /* 1x */   28, 28, 28, 28, 28,  7, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
85 /* 2x */   28, 28, 28, 28, 28,  7, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
86 /* 3x */   28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
87 /* 4x */    7, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 26, 12, 17, 20, 10,
88 /* 5x */   24, 28, 28, 28, 28, 28, 28, 28, 28, 28, 15,  4, 21, 18, 19, 28,
89 /* 6x */   11, 16, 28, 28, 28, 28, 28, 28, 28, 28, 28, 23, 22,  2, 13,  6,
90 /* 7x */   28, 28, 28, 28, 28, 28, 28, 28, 28,  8,  5,  5,  5,  8, 14,  8,
91 /* 8x */   28,  1,  1,  1,  1,  1,  1,  1,  1,  1, 28, 28, 28, 28, 28, 28,
92 /* 9x */   28,  1,  1,  1,  1,  1,  1,  1,  1,  1, 28, 28, 28, 28, 28, 28,
93 /* Ax */   28, 25,  1,  1,  1,  1,  1,  0,  2,  2, 28, 28, 28, 28, 28, 28,
94 /* Bx */   28, 28, 28, 28, 28, 28, 28, 28, 28, 28,  9, 28, 28, 28, 28, 28,
95 /* Cx */   28,  1,  1,  1,  1,  1,  1,  1,  1,  1, 28, 28, 28, 28, 28, 28,
96 /* Dx */   28,  1,  1,  1,  1,  1,  1,  1,  1,  1, 28, 28, 28, 28, 28, 28,
97 /* Ex */   28, 28,  1,  1,  1,  1,  1,  0,  2,  2, 28, 28, 28, 28, 28, 28,
98 /* Fx */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3, 28, 28, 28, 28, 28, 28,
99 #endif
100 };
101 
102 /*
103 ** The charMap() macro maps alphabetic characters (only) into their
104 ** lower-case ASCII equivalent.  On ASCII machines, this is just
105 ** an upper-to-lower case map.  On EBCDIC machines we also need
106 ** to adjust the encoding.  The mapping is only valid for alphabetics
107 ** which are the only characters for which this feature is used.
108 **
109 ** Used by keywordhash.h
110 */
111 #ifdef SQLITE_ASCII
112 # define charMap(X) sqlite3UpperToLower[(unsigned char)X]
113 #endif
114 #ifdef SQLITE_EBCDIC
115 # define charMap(X) ebcdicToAscii[(unsigned char)X]
116 const unsigned char ebcdicToAscii[] = {
117 /* 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F */
118    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 0x */
119    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 1x */
120    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 2x */
121    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 3x */
122    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 4x */
123    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 5x */
124    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 95,  0,  0,  /* 6x */
125    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 7x */
126    0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* 8x */
127    0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* 9x */
128    0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ax */
129    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Bx */
130    0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* Cx */
131    0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* Dx */
132    0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ex */
133    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Fx */
134 };
135 #endif
136 
137 /*
138 ** The sqlite3KeywordCode function looks up an identifier to determine if
139 ** it is a keyword.  If it is a keyword, the token code of that keyword is
140 ** returned.  If the input is not a keyword, TK_ID is returned.
141 **
142 ** The implementation of this routine was generated by a program,
143 ** mkkeywordhash.c, located in the tool subdirectory of the distribution.
144 ** The output of the mkkeywordhash.c program is written into a file
145 ** named keywordhash.h and then included into this source file by
146 ** the #include below.
147 */
148 #include "keywordhash.h"
149 
150 
151 /*
152 ** If X is a character that can be used in an identifier then
153 ** IdChar(X) will be true.  Otherwise it is false.
154 **
155 ** For ASCII, any character with the high-order bit set is
156 ** allowed in an identifier.  For 7-bit characters,
157 ** sqlite3IsIdChar[X] must be 1.
158 **
159 ** For EBCDIC, the rules are more complex but have the same
160 ** end result.
161 **
162 ** Ticket #1066.  the SQL standard does not allow '$' in the
163 ** middle of identifiers.  But many SQL implementations do.
164 ** SQLite will allow '$' in identifiers for compatibility.
165 ** But the feature is undocumented.
166 */
167 #ifdef SQLITE_ASCII
168 #define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
169 #endif
170 #ifdef SQLITE_EBCDIC
171 const char sqlite3IsEbcdicIdChar[] = {
172 /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
173     0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 4x */
174     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0,  /* 5x */
175     0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0,  /* 6x */
176     0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,  /* 7x */
177     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0,  /* 8x */
178     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0,  /* 9x */
179     1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0,  /* Ax */
180     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* Bx */
181     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Cx */
182     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Dx */
183     0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Ex */
184     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0,  /* Fx */
185 };
186 #define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
187 #endif
188 
189 /* Make the IdChar function accessible from ctime.c and alter.c */
190 int sqlite3IsIdChar(u8 c){ return IdChar(c); }
191 
192 #ifndef SQLITE_OMIT_WINDOWFUNC
193 /*
194 ** Return the id of the next token in string (*pz). Before returning, set
195 ** (*pz) to point to the byte following the parsed token.
196 */
197 static int getToken(const unsigned char **pz){
198   const unsigned char *z = *pz;
199   int t;                          /* Token type to return */
200   do {
201     z += sqlite3GetToken(z, &t);
202   }while( t==TK_SPACE );
203   if( t==TK_ID
204    || t==TK_STRING
205    || t==TK_JOIN_KW
206    || t==TK_WINDOW
207    || t==TK_OVER
208    || sqlite3ParserFallback(t)==TK_ID
209   ){
210     t = TK_ID;
211   }
212   *pz = z;
213   return t;
214 }
215 
216 /*
217 ** The following three functions are called immediately after the tokenizer
218 ** reads the keywords WINDOW, OVER and FILTER, respectively, to determine
219 ** whether the token should be treated as a keyword or an SQL identifier.
220 ** This cannot be handled by the usual lemon %fallback method, due to
221 ** the ambiguity in some constructions. e.g.
222 **
223 **   SELECT sum(x) OVER ...
224 **
225 ** In the above, "OVER" might be a keyword, or it might be an alias for the
226 ** sum(x) expression. If a "%fallback ID OVER" directive were added to
227 ** grammar, then SQLite would always treat "OVER" as an alias, making it
228 ** impossible to call a window-function without a FILTER clause.
229 **
230 ** WINDOW is treated as a keyword if:
231 **
232 **   * the following token is an identifier, or a keyword that can fallback
233 **     to being an identifier, and
234 **   * the token after than one is TK_AS.
235 **
236 ** OVER is a keyword if:
237 **
238 **   * the previous token was TK_RP, and
239 **   * the next token is either TK_LP or an identifier.
240 **
241 ** FILTER is a keyword if:
242 **
243 **   * the previous token was TK_RP, and
244 **   * the next token is TK_LP.
245 */
246 static int analyzeWindowKeyword(const unsigned char *z){
247   int t;
248   t = getToken(&z);
249   if( t!=TK_ID ) return TK_ID;
250   t = getToken(&z);
251   if( t!=TK_AS ) return TK_ID;
252   return TK_WINDOW;
253 }
254 static int analyzeOverKeyword(const unsigned char *z, int lastToken){
255   if( lastToken==TK_RP ){
256     int t = getToken(&z);
257     if( t==TK_LP || t==TK_ID ) return TK_OVER;
258   }
259   return TK_ID;
260 }
261 static int analyzeFilterKeyword(const unsigned char *z, int lastToken){
262   if( lastToken==TK_RP && getToken(&z)==TK_LP ){
263     return TK_FILTER;
264   }
265   return TK_ID;
266 }
267 #endif /* SQLITE_OMIT_WINDOWFUNC */
268 
269 /*
270 ** Return the length (in bytes) of the token that begins at z[0].
271 ** Store the token type in *tokenType before returning.
272 */
273 int sqlite3GetToken(const unsigned char *z, int *tokenType){
274   int i, c;
275   switch( aiClass[*z] ){  /* Switch on the character-class of the first byte
276                           ** of the token. See the comment on the CC_ defines
277                           ** above. */
278     case CC_SPACE: {
279       testcase( z[0]==' ' );
280       testcase( z[0]=='\t' );
281       testcase( z[0]=='\n' );
282       testcase( z[0]=='\f' );
283       testcase( z[0]=='\r' );
284       for(i=1; sqlite3Isspace(z[i]); i++){}
285       *tokenType = TK_SPACE;
286       return i;
287     }
288     case CC_MINUS: {
289       if( z[1]=='-' ){
290         for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
291         *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
292         return i;
293       }
294       *tokenType = TK_MINUS;
295       return 1;
296     }
297     case CC_LP: {
298       *tokenType = TK_LP;
299       return 1;
300     }
301     case CC_RP: {
302       *tokenType = TK_RP;
303       return 1;
304     }
305     case CC_SEMI: {
306       *tokenType = TK_SEMI;
307       return 1;
308     }
309     case CC_PLUS: {
310       *tokenType = TK_PLUS;
311       return 1;
312     }
313     case CC_STAR: {
314       *tokenType = TK_STAR;
315       return 1;
316     }
317     case CC_SLASH: {
318       if( z[1]!='*' || z[2]==0 ){
319         *tokenType = TK_SLASH;
320         return 1;
321       }
322       for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
323       if( c ) i++;
324       *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
325       return i;
326     }
327     case CC_PERCENT: {
328       *tokenType = TK_REM;
329       return 1;
330     }
331     case CC_EQ: {
332       *tokenType = TK_EQ;
333       return 1 + (z[1]=='=');
334     }
335     case CC_LT: {
336       if( (c=z[1])=='=' ){
337         *tokenType = TK_LE;
338         return 2;
339       }else if( c=='>' ){
340         *tokenType = TK_NE;
341         return 2;
342       }else if( c=='<' ){
343         *tokenType = TK_LSHIFT;
344         return 2;
345       }else{
346         *tokenType = TK_LT;
347         return 1;
348       }
349     }
350     case CC_GT: {
351       if( (c=z[1])=='=' ){
352         *tokenType = TK_GE;
353         return 2;
354       }else if( c=='>' ){
355         *tokenType = TK_RSHIFT;
356         return 2;
357       }else{
358         *tokenType = TK_GT;
359         return 1;
360       }
361     }
362     case CC_BANG: {
363       if( z[1]!='=' ){
364         *tokenType = TK_ILLEGAL;
365         return 1;
366       }else{
367         *tokenType = TK_NE;
368         return 2;
369       }
370     }
371     case CC_PIPE: {
372       if( z[1]!='|' ){
373         *tokenType = TK_BITOR;
374         return 1;
375       }else{
376         *tokenType = TK_CONCAT;
377         return 2;
378       }
379     }
380     case CC_COMMA: {
381       *tokenType = TK_COMMA;
382       return 1;
383     }
384     case CC_AND: {
385       *tokenType = TK_BITAND;
386       return 1;
387     }
388     case CC_TILDA: {
389       *tokenType = TK_BITNOT;
390       return 1;
391     }
392     case CC_QUOTE: {
393       int delim = z[0];
394       testcase( delim=='`' );
395       testcase( delim=='\'' );
396       testcase( delim=='"' );
397       for(i=1; (c=z[i])!=0; i++){
398         if( c==delim ){
399           if( z[i+1]==delim ){
400             i++;
401           }else{
402             break;
403           }
404         }
405       }
406       if( c=='\'' ){
407         *tokenType = TK_STRING;
408         return i+1;
409       }else if( c!=0 ){
410         *tokenType = TK_ID;
411         return i+1;
412       }else{
413         *tokenType = TK_ILLEGAL;
414         return i;
415       }
416     }
417     case CC_DOT: {
418 #ifndef SQLITE_OMIT_FLOATING_POINT
419       if( !sqlite3Isdigit(z[1]) )
420 #endif
421       {
422         *tokenType = TK_DOT;
423         return 1;
424       }
425       /* If the next character is a digit, this is a floating point
426       ** number that begins with ".".  Fall thru into the next case */
427       /* no break */ deliberate_fall_through
428     }
429     case CC_DIGIT: {
430       testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
431       testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );
432       testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );
433       testcase( z[0]=='9' );
434       *tokenType = TK_INTEGER;
435 #ifndef SQLITE_OMIT_HEX_INTEGER
436       if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){
437         for(i=3; sqlite3Isxdigit(z[i]); i++){}
438         return i;
439       }
440 #endif
441       for(i=0; sqlite3Isdigit(z[i]); i++){}
442 #ifndef SQLITE_OMIT_FLOATING_POINT
443       if( z[i]=='.' ){
444         i++;
445         while( sqlite3Isdigit(z[i]) ){ i++; }
446         *tokenType = TK_FLOAT;
447       }
448       if( (z[i]=='e' || z[i]=='E') &&
449            ( sqlite3Isdigit(z[i+1])
450             || ((z[i+1]=='+' || z[i+1]=='-') && sqlite3Isdigit(z[i+2]))
451            )
452       ){
453         i += 2;
454         while( sqlite3Isdigit(z[i]) ){ i++; }
455         *tokenType = TK_FLOAT;
456       }
457 #endif
458       while( IdChar(z[i]) ){
459         *tokenType = TK_ILLEGAL;
460         i++;
461       }
462       return i;
463     }
464     case CC_QUOTE2: {
465       for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
466       *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
467       return i;
468     }
469     case CC_VARNUM: {
470       *tokenType = TK_VARIABLE;
471       for(i=1; sqlite3Isdigit(z[i]); i++){}
472       return i;
473     }
474     case CC_DOLLAR:
475     case CC_VARALPHA: {
476       int n = 0;
477       testcase( z[0]=='$' );  testcase( z[0]=='@' );
478       testcase( z[0]==':' );  testcase( z[0]=='#' );
479       *tokenType = TK_VARIABLE;
480       for(i=1; (c=z[i])!=0; i++){
481         if( IdChar(c) ){
482           n++;
483 #ifndef SQLITE_OMIT_TCL_VARIABLE
484         }else if( c=='(' && n>0 ){
485           do{
486             i++;
487           }while( (c=z[i])!=0 && !sqlite3Isspace(c) && c!=')' );
488           if( c==')' ){
489             i++;
490           }else{
491             *tokenType = TK_ILLEGAL;
492           }
493           break;
494         }else if( c==':' && z[i+1]==':' ){
495           i++;
496 #endif
497         }else{
498           break;
499         }
500       }
501       if( n==0 ) *tokenType = TK_ILLEGAL;
502       return i;
503     }
504     case CC_KYWD0: {
505       for(i=1; aiClass[z[i]]<=CC_KYWD; i++){}
506       if( IdChar(z[i]) ){
507         /* This token started out using characters that can appear in keywords,
508         ** but z[i] is a character not allowed within keywords, so this must
509         ** be an identifier instead */
510         i++;
511         break;
512       }
513       *tokenType = TK_ID;
514       return keywordCode((char*)z, i, tokenType);
515     }
516     case CC_X: {
517 #ifndef SQLITE_OMIT_BLOB_LITERAL
518       testcase( z[0]=='x' ); testcase( z[0]=='X' );
519       if( z[1]=='\'' ){
520         *tokenType = TK_BLOB;
521         for(i=2; sqlite3Isxdigit(z[i]); i++){}
522         if( z[i]!='\'' || i%2 ){
523           *tokenType = TK_ILLEGAL;
524           while( z[i] && z[i]!='\'' ){ i++; }
525         }
526         if( z[i] ) i++;
527         return i;
528       }
529 #endif
530       /* If it is not a BLOB literal, then it must be an ID, since no
531       ** SQL keywords start with the letter 'x'.  Fall through */
532       /* no break */ deliberate_fall_through
533     }
534     case CC_KYWD:
535     case CC_ID: {
536       i = 1;
537       break;
538     }
539     case CC_BOM: {
540       if( z[1]==0xbb && z[2]==0xbf ){
541         *tokenType = TK_SPACE;
542         return 3;
543       }
544       i = 1;
545       break;
546     }
547     case CC_NUL: {
548       *tokenType = TK_ILLEGAL;
549       return 0;
550     }
551     default: {
552       *tokenType = TK_ILLEGAL;
553       return 1;
554     }
555   }
556   while( IdChar(z[i]) ){ i++; }
557   *tokenType = TK_ID;
558   return i;
559 }
560 
561 /*
562 ** Run the parser on the given SQL string.
563 */
564 int sqlite3RunParser(Parse *pParse, const char *zSql){
565   int nErr = 0;                   /* Number of errors encountered */
566   void *pEngine;                  /* The LEMON-generated LALR(1) parser */
567   int n = 0;                      /* Length of the next token token */
568   int tokenType;                  /* type of the next token */
569   int lastTokenParsed = -1;       /* type of the previous token */
570   sqlite3 *db = pParse->db;       /* The database connection */
571   int mxSqlLen;                   /* Max length of an SQL string */
572   Parse *pParentParse = 0;        /* Outer parse context, if any */
573 #ifdef sqlite3Parser_ENGINEALWAYSONSTACK
574   yyParser sEngine;    /* Space to hold the Lemon-generated Parser object */
575 #endif
576   VVA_ONLY( u8 startedWithOom = db->mallocFailed );
577 
578   assert( zSql!=0 );
579   mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
580   if( db->nVdbeActive==0 ){
581     AtomicStore(&db->u1.isInterrupted, 0);
582   }
583   pParse->rc = SQLITE_OK;
584   pParse->zTail = zSql;
585 #ifdef SQLITE_DEBUG
586   if( db->flags & SQLITE_ParserTrace ){
587     printf("parser: [[[%s]]]\n", zSql);
588     sqlite3ParserTrace(stdout, "parser: ");
589   }else{
590     sqlite3ParserTrace(0, 0);
591   }
592 #endif
593 #ifdef sqlite3Parser_ENGINEALWAYSONSTACK
594   pEngine = &sEngine;
595   sqlite3ParserInit(pEngine, pParse);
596 #else
597   pEngine = sqlite3ParserAlloc(sqlite3Malloc, pParse);
598   if( pEngine==0 ){
599     sqlite3OomFault(db);
600     return SQLITE_NOMEM_BKPT;
601   }
602 #endif
603   assert( pParse->pNewTable==0 );
604   assert( pParse->pNewTrigger==0 );
605   assert( pParse->nVar==0 );
606   assert( pParse->pVList==0 );
607   pParentParse = db->pParse;
608   db->pParse = pParse;
609   while( 1 ){
610     n = sqlite3GetToken((u8*)zSql, &tokenType);
611     mxSqlLen -= n;
612     if( mxSqlLen<0 ){
613       pParse->rc = SQLITE_TOOBIG;
614       break;
615     }
616 #ifndef SQLITE_OMIT_WINDOWFUNC
617     if( tokenType>=TK_WINDOW ){
618       assert( tokenType==TK_SPACE || tokenType==TK_OVER || tokenType==TK_FILTER
619            || tokenType==TK_ILLEGAL || tokenType==TK_WINDOW
620       );
621 #else
622     if( tokenType>=TK_SPACE ){
623       assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
624 #endif /* SQLITE_OMIT_WINDOWFUNC */
625       if( AtomicLoad(&db->u1.isInterrupted) ){
626         pParse->rc = SQLITE_INTERRUPT;
627         pParse->nErr++;
628         break;
629       }
630       if( tokenType==TK_SPACE ){
631         zSql += n;
632         continue;
633       }
634       if( zSql[0]==0 ){
635         /* Upon reaching the end of input, call the parser two more times
636         ** with tokens TK_SEMI and 0, in that order. */
637         if( lastTokenParsed==TK_SEMI ){
638           tokenType = 0;
639         }else if( lastTokenParsed==0 ){
640           break;
641         }else{
642           tokenType = TK_SEMI;
643         }
644         n = 0;
645 #ifndef SQLITE_OMIT_WINDOWFUNC
646       }else if( tokenType==TK_WINDOW ){
647         assert( n==6 );
648         tokenType = analyzeWindowKeyword((const u8*)&zSql[6]);
649       }else if( tokenType==TK_OVER ){
650         assert( n==4 );
651         tokenType = analyzeOverKeyword((const u8*)&zSql[4], lastTokenParsed);
652       }else if( tokenType==TK_FILTER ){
653         assert( n==6 );
654         tokenType = analyzeFilterKeyword((const u8*)&zSql[6], lastTokenParsed);
655 #endif /* SQLITE_OMIT_WINDOWFUNC */
656       }else{
657         sqlite3ErrorMsg(pParse, "unrecognized token: \"%.*s\"", n, zSql);
658         break;
659       }
660     }
661     pParse->sLastToken.z = zSql;
662     pParse->sLastToken.n = n;
663     sqlite3Parser(pEngine, tokenType, pParse->sLastToken);
664     lastTokenParsed = tokenType;
665     zSql += n;
666     assert( db->mallocFailed==0 || pParse->rc!=SQLITE_OK || startedWithOom );
667     if( pParse->rc!=SQLITE_OK ) break;
668   }
669   assert( nErr==0 );
670 #ifdef YYTRACKMAXSTACKDEPTH
671   sqlite3_mutex_enter(sqlite3MallocMutex());
672   sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,
673       sqlite3ParserStackPeak(pEngine)
674   );
675   sqlite3_mutex_leave(sqlite3MallocMutex());
676 #endif /* YYDEBUG */
677 #ifdef sqlite3Parser_ENGINEALWAYSONSTACK
678   sqlite3ParserFinalize(pEngine);
679 #else
680   sqlite3ParserFree(pEngine, sqlite3_free);
681 #endif
682   if( db->mallocFailed ){
683     pParse->rc = SQLITE_NOMEM_BKPT;
684   }
685   if( pParse->zErrMsg || (pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE) ){
686     if( pParse->zErrMsg==0 ){
687       pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));
688     }
689     sqlite3_log(pParse->rc, "%s in \"%s\"", pParse->zErrMsg, pParse->zTail);
690     nErr++;
691   }
692   pParse->zTail = zSql;
693 #ifndef SQLITE_OMIT_VIRTUALTABLE
694   sqlite3_free(pParse->apVtabLock);
695 #endif
696 
697   if( pParse->pNewTable && !IN_SPECIAL_PARSE ){
698     /* If the pParse->declareVtab flag is set, do not delete any table
699     ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
700     ** will take responsibility for freeing the Table structure.
701     */
702     sqlite3DeleteTable(db, pParse->pNewTable);
703   }
704   if( pParse->pNewTrigger && !IN_RENAME_OBJECT ){
705     sqlite3DeleteTrigger(db, pParse->pNewTrigger);
706   }
707   sqlite3DbFree(db, pParse->pVList);
708   db->pParse = pParentParse;
709   assert( nErr==0 || pParse->rc!=SQLITE_OK );
710   return nErr;
711 }
712 
713 
714 #ifdef SQLITE_ENABLE_NORMALIZE
715 /*
716 ** Insert a single space character into pStr if the current string
717 ** ends with an identifier
718 */
719 static void addSpaceSeparator(sqlite3_str *pStr){
720   if( pStr->nChar && sqlite3IsIdChar(pStr->zText[pStr->nChar-1]) ){
721     sqlite3_str_append(pStr, " ", 1);
722   }
723 }
724 
725 /*
726 ** Compute a normalization of the SQL given by zSql[0..nSql-1].  Return
727 ** the normalization in space obtained from sqlite3DbMalloc().  Or return
728 ** NULL if anything goes wrong or if zSql is NULL.
729 */
730 char *sqlite3Normalize(
731   Vdbe *pVdbe,       /* VM being reprepared */
732   const char *zSql   /* The original SQL string */
733 ){
734   sqlite3 *db;       /* The database connection */
735   int i;             /* Next unread byte of zSql[] */
736   int n;             /* length of current token */
737   int tokenType;     /* type of current token */
738   int prevType = 0;  /* Previous non-whitespace token */
739   int nParen;        /* Number of nested levels of parentheses */
740   int iStartIN;      /* Start of RHS of IN operator in z[] */
741   int nParenAtIN;    /* Value of nParent at start of RHS of IN operator */
742   u32 j;             /* Bytes of normalized SQL generated so far */
743   sqlite3_str *pStr; /* The normalized SQL string under construction */
744 
745   db = sqlite3VdbeDb(pVdbe);
746   tokenType = -1;
747   nParen = iStartIN = nParenAtIN = 0;
748   pStr = sqlite3_str_new(db);
749   assert( pStr!=0 );  /* sqlite3_str_new() never returns NULL */
750   for(i=0; zSql[i] && pStr->accError==0; i+=n){
751     if( tokenType!=TK_SPACE ){
752       prevType = tokenType;
753     }
754     n = sqlite3GetToken((unsigned char*)zSql+i, &tokenType);
755     if( NEVER(n<=0) ) break;
756     switch( tokenType ){
757       case TK_SPACE: {
758         break;
759       }
760       case TK_NULL: {
761         if( prevType==TK_IS || prevType==TK_NOT ){
762           sqlite3_str_append(pStr, " NULL", 5);
763           break;
764         }
765         /* Fall through */
766       }
767       case TK_STRING:
768       case TK_INTEGER:
769       case TK_FLOAT:
770       case TK_VARIABLE:
771       case TK_BLOB: {
772         sqlite3_str_append(pStr, "?", 1);
773         break;
774       }
775       case TK_LP: {
776         nParen++;
777         if( prevType==TK_IN ){
778           iStartIN = pStr->nChar;
779           nParenAtIN = nParen;
780         }
781         sqlite3_str_append(pStr, "(", 1);
782         break;
783       }
784       case TK_RP: {
785         if( iStartIN>0 && nParen==nParenAtIN ){
786           assert( pStr->nChar>=(u32)iStartIN );
787           pStr->nChar = iStartIN+1;
788           sqlite3_str_append(pStr, "?,?,?", 5);
789           iStartIN = 0;
790         }
791         nParen--;
792         sqlite3_str_append(pStr, ")", 1);
793         break;
794       }
795       case TK_ID: {
796         iStartIN = 0;
797         j = pStr->nChar;
798         if( sqlite3Isquote(zSql[i]) ){
799           char *zId = sqlite3DbStrNDup(db, zSql+i, n);
800           int nId;
801           int eType = 0;
802           if( zId==0 ) break;
803           sqlite3Dequote(zId);
804           if( zSql[i]=='"' && sqlite3VdbeUsesDoubleQuotedString(pVdbe, zId) ){
805             sqlite3_str_append(pStr, "?", 1);
806             sqlite3DbFree(db, zId);
807             break;
808           }
809           nId = sqlite3Strlen30(zId);
810           if( sqlite3GetToken((u8*)zId, &eType)==nId && eType==TK_ID ){
811             addSpaceSeparator(pStr);
812             sqlite3_str_append(pStr, zId, nId);
813           }else{
814             sqlite3_str_appendf(pStr, "\"%w\"", zId);
815           }
816           sqlite3DbFree(db, zId);
817         }else{
818           addSpaceSeparator(pStr);
819           sqlite3_str_append(pStr, zSql+i, n);
820         }
821         while( j<pStr->nChar ){
822           pStr->zText[j] = sqlite3Tolower(pStr->zText[j]);
823           j++;
824         }
825         break;
826       }
827       case TK_SELECT: {
828         iStartIN = 0;
829         /* fall through */
830       }
831       default: {
832         if( sqlite3IsIdChar(zSql[i]) ) addSpaceSeparator(pStr);
833         j = pStr->nChar;
834         sqlite3_str_append(pStr, zSql+i, n);
835         while( j<pStr->nChar ){
836           pStr->zText[j] = sqlite3Toupper(pStr->zText[j]);
837           j++;
838         }
839         break;
840       }
841     }
842   }
843   if( tokenType!=TK_SEMI ) sqlite3_str_append(pStr, ";", 1);
844   return sqlite3_str_finish(pStr);
845 }
846 #endif /* SQLITE_ENABLE_NORMALIZE */
847