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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 implements the sqlite3_complete() API.
15** This code used to be part of the tokenizer.c source file. But by
16** separating it out, the code will be automatically omitted from
17** static links that do not use it.
18**
19** $Id: complete.c,v 1.3 2006/01/18 15:25:17 danielk1977 Exp $
20*/
21#include "sqliteInt.h"
22#ifndef SQLITE_OMIT_COMPLETE
23
24/*
25** This is defined in tokenize.c. We just have to import the definition.
26*/
27extern const char sqlite3IsIdChar[];
28#define IdChar(C) (((c=C)&0x80)!=0 || (c>0x1f && sqlite3IsIdChar[c-0x20]))
29
30
31/*
32** Token types used by the sqlite3_complete() routine. See the header
33** comments on that procedure for additional information.
34*/
35#define tkSEMI 0
36#define tkWS 1
37#define tkOTHER 2
38#define tkEXPLAIN 3
39#define tkCREATE 4
40#define tkTEMP 5
41#define tkTRIGGER 6
42#define tkEND 7
43
44/*
45** Return TRUE if the given SQL string ends in a semicolon.
46**
47** Special handling is require for CREATE TRIGGER statements.
48** Whenever the CREATE TRIGGER keywords are seen, the statement
49** must end with ";END;".
50**
51** This implementation uses a state machine with 7 states:
52**
53** (0) START At the beginning or end of an SQL statement. This routine
54** returns 1 if it ends in the START state and 0 if it ends
55** in any other state.
56**
57** (1) NORMAL We are in the middle of statement which ends with a single
58** semicolon.
59**
60** (2) EXPLAIN The keyword EXPLAIN has been seen at the beginning of
61** a statement.
62**
63** (3) CREATE The keyword CREATE has been seen at the beginning of a
64** statement, possibly preceeded by EXPLAIN and/or followed by
65** TEMP or TEMPORARY
66**
67** (4) TRIGGER We are in the middle of a trigger definition that must be
68** ended by a semicolon, the keyword END, and another semicolon.
69**
70** (5) SEMI We've seen the first semicolon in the ";END;" that occurs at
71** the end of a trigger definition.
72**
73** (6) END We've seen the ";END" of the ";END;" that occurs at the end
74** of a trigger difinition.
75**
76** Transitions between states above are determined by tokens extracted
77** from the input. The following tokens are significant:
78**
79** (0) tkSEMI A semicolon.
80** (1) tkWS Whitespace
81** (2) tkOTHER Any other SQL token.
82** (3) tkEXPLAIN The "explain" keyword.
83** (4) tkCREATE The "create" keyword.
84** (5) tkTEMP The "temp" or "temporary" keyword.
85** (6) tkTRIGGER The "trigger" keyword.
86** (7) tkEND The "end" keyword.
87**
88** Whitespace never causes a state transition and is always ignored.
89**
90** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
91** to recognize the end of a trigger can be omitted. All we have to do
92** is look for a semicolon that is not part of an string or comment.
93*/
94int sqlite3_complete(const char *zSql){
95 u8 state = 0; /* Current state, using numbers defined in header comment */
96 u8 token; /* Value of the next token */
97
98#ifndef SQLITE_OMIT_TRIGGER
99 /* A complex statement machine used to detect the end of a CREATE TRIGGER
100 ** statement. This is the normal case.
101 */
102 static const u8 trans[7][8] = {
103 /* Token: */
104 /* State: ** SEMI WS OTHER EXPLAIN CREATE TEMP TRIGGER END */
105 /* 0 START: */ { 0, 0, 1, 2, 3, 1, 1, 1, },
106 /* 1 NORMAL: */ { 0, 1, 1, 1, 1, 1, 1, 1, },
107 /* 2 EXPLAIN: */ { 0, 2, 1, 1, 3, 1, 1, 1, },
108 /* 3 CREATE: */ { 0, 3, 1, 1, 1, 3, 4, 1, },
109 /* 4 TRIGGER: */ { 5, 4, 4, 4, 4, 4, 4, 4, },
110 /* 5 SEMI: */ { 5, 5, 4, 4, 4, 4, 4, 6, },
111 /* 6 END: */ { 0, 6, 4, 4, 4, 4, 4, 4, },
112 };
113#else
114 /* If triggers are not suppored by this compile then the statement machine
115 ** used to detect the end of a statement is much simplier
116 */
117 static const u8 trans[2][3] = {
118 /* Token: */
119 /* State: ** SEMI WS OTHER */
120 /* 0 START: */ { 0, 0, 1, },
121 /* 1 NORMAL: */ { 0, 1, 1, },
122 };
123#endif /* SQLITE_OMIT_TRIGGER */
124
125 while( *zSql ){
126 switch( *zSql ){
127 case ';': { /* A semicolon */
128 token = tkSEMI;
129 break;
130 }
131 case ' ':
132 case '\r':
133 case '\t':
134 case '\n':
135 case '\f': { /* White space is ignored */
136 token = tkWS;
137 break;
138 }
139 case '/': { /* C-style comments */
140 if( zSql[1]!='*' ){
141 token = tkOTHER;
142 break;
143 }
144 zSql += 2;
145 while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }
146 if( zSql[0]==0 ) return 0;
147 zSql++;
148 token = tkWS;
149 break;
150 }
151 case '-': { /* SQL-style comments from "--" to end of line */
152 if( zSql[1]!='-' ){
153 token = tkOTHER;
154 break;
155 }
156 while( *zSql && *zSql!='\n' ){ zSql++; }
157 if( *zSql==0 ) return state==0;
158 token = tkWS;
159 break;
160 }
161 case '[': { /* Microsoft-style identifiers in [...] */
162 zSql++;
163 while( *zSql && *zSql!=']' ){ zSql++; }
164 if( *zSql==0 ) return 0;
165 token = tkOTHER;
166 break;
167 }
168 case '`': /* Grave-accent quoted symbols used by MySQL */
169 case '"': /* single- and double-quoted strings */
170 case '\'': {
171 int c = *zSql;
172 zSql++;
173 while( *zSql && *zSql!=c ){ zSql++; }
174 if( *zSql==0 ) return 0;
175 token = tkOTHER;
176 break;
177 }
178 default: {
179 int c;
180 if( IdChar((u8)*zSql) ){
181 /* Keywords and unquoted identifiers */
182 int nId;
183 for(nId=1; IdChar(zSql[nId]); nId++){}
184#ifdef SQLITE_OMIT_TRIGGER
185 token = tkOTHER;
186#else
187 switch( *zSql ){
188 case 'c': case 'C': {
189 if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){
190 token = tkCREATE;
191 }else{
192 token = tkOTHER;
193 }
194 break;
195 }
196 case 't': case 'T': {
197 if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){
198 token = tkTRIGGER;
199 }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){
200 token = tkTEMP;
201 }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){
202 token = tkTEMP;
203 }else{
204 token = tkOTHER;
205 }
206 break;
207 }
208 case 'e': case 'E': {
209 if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){
210 token = tkEND;
211 }else
212#ifndef SQLITE_OMIT_EXPLAIN
213 if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){
214 token = tkEXPLAIN;
215 }else
216#endif
217 {
218 token = tkOTHER;
219 }
220 break;
221 }
222 default: {
223 token = tkOTHER;
224 break;
225 }
226 }
227#endif /* SQLITE_OMIT_TRIGGER */
228 zSql += nId-1;
229 }else{
230 /* Operators and special symbols */
231 token = tkOTHER;
232 }
233 break;
234 }
235 }
236 state = trans[state][token];
237 zSql++;
238 }
239 return state==0;
240}
241
242#ifndef SQLITE_OMIT_UTF16
243/*
244** This routine is the same as the sqlite3_complete() routine described
245** above, except that the parameter is required to be UTF-16 encoded, not
246** UTF-8.
247*/
248int sqlite3_complete16(const void *zSql){
249 sqlite3_value *pVal;
250 char const *zSql8;
251 int rc = 0;
252
253 pVal = sqlite3ValueNew();
254 sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
255 zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
256 if( zSql8 ){
257 rc = sqlite3_complete(zSql8);
258 }
259 sqlite3ValueFree(pVal);
260 return sqlite3ApiExit(0, rc);
261}
262#endif /* SQLITE_OMIT_UTF16 */
263#endif /* SQLITE_OMIT_COMPLETE */

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