complete.c
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- /*
- ** 2001 September 15
- **
- ** The author disclaims copyright to this source code. In place of
- ** a legal notice, here is a blessing:
- **
- ** May you do good and not evil.
- ** May you find forgiveness for yourself and forgive others.
- ** May you share freely, never taking more than you give.
- **
- *************************************************************************
- ** An tokenizer for SQL
- **
- ** This file contains C code that implements the sqlite3_complete() API.
- ** This code used to be part of the tokenizer.c source file. But by
- ** separating it out, the code will be automatically omitted from
- ** static links that do not use it.
- **
- ** $Id: complete.c,v 1.6 2007/08/27 23:26:59 drh Exp $
- */
- #include "sqliteInt.h"
- #ifndef SQLITE_OMIT_COMPLETE
- /*
- ** This is defined in tokenize.c. We just have to import the definition.
- */
- #ifndef SQLITE_AMALGAMATION
- #ifdef SQLITE_ASCII
- extern const char sqlite3IsAsciiIdChar[];
- #define IdChar(C) (((c=C)&0x80)!=0 || (c>0x1f && sqlite3IsAsciiIdChar[c-0x20]))
- #endif
- #ifdef SQLITE_EBCDIC
- extern const char sqlite3IsEbcdicIdChar[];
- #define IdChar(C) (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
- #endif
- #endif /* SQLITE_AMALGAMATION */
- /*
- ** Token types used by the sqlite3_complete() routine. See the header
- ** comments on that procedure for additional information.
- */
- #define tkSEMI 0
- #define tkWS 1
- #define tkOTHER 2
- #define tkEXPLAIN 3
- #define tkCREATE 4
- #define tkTEMP 5
- #define tkTRIGGER 6
- #define tkEND 7
- /*
- ** Return TRUE if the given SQL string ends in a semicolon.
- **
- ** Special handling is require for CREATE TRIGGER statements.
- ** Whenever the CREATE TRIGGER keywords are seen, the statement
- ** must end with ";END;".
- **
- ** This implementation uses a state machine with 7 states:
- **
- ** (0) START At the beginning or end of an SQL statement. This routine
- ** returns 1 if it ends in the START state and 0 if it ends
- ** in any other state.
- **
- ** (1) NORMAL We are in the middle of statement which ends with a single
- ** semicolon.
- **
- ** (2) EXPLAIN The keyword EXPLAIN has been seen at the beginning of
- ** a statement.
- **
- ** (3) CREATE The keyword CREATE has been seen at the beginning of a
- ** statement, possibly preceeded by EXPLAIN and/or followed by
- ** TEMP or TEMPORARY
- **
- ** (4) TRIGGER We are in the middle of a trigger definition that must be
- ** ended by a semicolon, the keyword END, and another semicolon.
- **
- ** (5) SEMI We've seen the first semicolon in the ";END;" that occurs at
- ** the end of a trigger definition.
- **
- ** (6) END We've seen the ";END" of the ";END;" that occurs at the end
- ** of a trigger difinition.
- **
- ** Transitions between states above are determined by tokens extracted
- ** from the input. The following tokens are significant:
- **
- ** (0) tkSEMI A semicolon.
- ** (1) tkWS Whitespace
- ** (2) tkOTHER Any other SQL token.
- ** (3) tkEXPLAIN The "explain" keyword.
- ** (4) tkCREATE The "create" keyword.
- ** (5) tkTEMP The "temp" or "temporary" keyword.
- ** (6) tkTRIGGER The "trigger" keyword.
- ** (7) tkEND The "end" keyword.
- **
- ** Whitespace never causes a state transition and is always ignored.
- **
- ** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
- ** to recognize the end of a trigger can be omitted. All we have to do
- ** is look for a semicolon that is not part of an string or comment.
- */
- int sqlite3_complete(const char *zSql){
- u8 state = 0; /* Current state, using numbers defined in header comment */
- u8 token; /* Value of the next token */
- #ifndef SQLITE_OMIT_TRIGGER
- /* A complex statement machine used to detect the end of a CREATE TRIGGER
- ** statement. This is the normal case.
- */
- static const u8 trans[7][8] = {
- /* Token: */
- /* State: ** SEMI WS OTHER EXPLAIN CREATE TEMP TRIGGER END */
- /* 0 START: */ { 0, 0, 1, 2, 3, 1, 1, 1, },
- /* 1 NORMAL: */ { 0, 1, 1, 1, 1, 1, 1, 1, },
- /* 2 EXPLAIN: */ { 0, 2, 1, 1, 3, 1, 1, 1, },
- /* 3 CREATE: */ { 0, 3, 1, 1, 1, 3, 4, 1, },
- /* 4 TRIGGER: */ { 5, 4, 4, 4, 4, 4, 4, 4, },
- /* 5 SEMI: */ { 5, 5, 4, 4, 4, 4, 4, 6, },
- /* 6 END: */ { 0, 6, 4, 4, 4, 4, 4, 4, },
- };
- #else
- /* If triggers are not suppored by this compile then the statement machine
- ** used to detect the end of a statement is much simplier
- */
- static const u8 trans[2][3] = {
- /* Token: */
- /* State: ** SEMI WS OTHER */
- /* 0 START: */ { 0, 0, 1, },
- /* 1 NORMAL: */ { 0, 1, 1, },
- };
- #endif /* SQLITE_OMIT_TRIGGER */
- while( *zSql ){
- switch( *zSql ){
- case ';': { /* A semicolon */
- token = tkSEMI;
- break;
- }
- case ' ':
- case 'r':
- case 't':
- case 'n':
- case 'f': { /* White space is ignored */
- token = tkWS;
- break;
- }
- case '/': { /* C-style comments */
- if( zSql[1]!='*' ){
- token = tkOTHER;
- break;
- }
- zSql += 2;
- while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }
- if( zSql[0]==0 ) return 0;
- zSql++;
- token = tkWS;
- break;
- }
- case '-': { /* SQL-style comments from "--" to end of line */
- if( zSql[1]!='-' ){
- token = tkOTHER;
- break;
- }
- while( *zSql && *zSql!='n' ){ zSql++; }
- if( *zSql==0 ) return state==0;
- token = tkWS;
- break;
- }
- case '[': { /* Microsoft-style identifiers in [...] */
- zSql++;
- while( *zSql && *zSql!=']' ){ zSql++; }
- if( *zSql==0 ) return 0;
- token = tkOTHER;
- break;
- }
- case '`': /* Grave-accent quoted symbols used by MySQL */
- case '"': /* single- and double-quoted strings */
- case ''': {
- int c = *zSql;
- zSql++;
- while( *zSql && *zSql!=c ){ zSql++; }
- if( *zSql==0 ) return 0;
- token = tkOTHER;
- break;
- }
- default: {
- int c;
- if( IdChar((u8)*zSql) ){
- /* Keywords and unquoted identifiers */
- int nId;
- for(nId=1; IdChar(zSql[nId]); nId++){}
- #ifdef SQLITE_OMIT_TRIGGER
- token = tkOTHER;
- #else
- switch( *zSql ){
- case 'c': case 'C': {
- if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){
- token = tkCREATE;
- }else{
- token = tkOTHER;
- }
- break;
- }
- case 't': case 'T': {
- if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){
- token = tkTRIGGER;
- }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){
- token = tkTEMP;
- }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){
- token = tkTEMP;
- }else{
- token = tkOTHER;
- }
- break;
- }
- case 'e': case 'E': {
- if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){
- token = tkEND;
- }else
- #ifndef SQLITE_OMIT_EXPLAIN
- if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){
- token = tkEXPLAIN;
- }else
- #endif
- {
- token = tkOTHER;
- }
- break;
- }
- default: {
- token = tkOTHER;
- break;
- }
- }
- #endif /* SQLITE_OMIT_TRIGGER */
- zSql += nId-1;
- }else{
- /* Operators and special symbols */
- token = tkOTHER;
- }
- break;
- }
- }
- state = trans[state][token];
- zSql++;
- }
- return state==0;
- }
- #ifndef SQLITE_OMIT_UTF16
- /*
- ** This routine is the same as the sqlite3_complete() routine described
- ** above, except that the parameter is required to be UTF-16 encoded, not
- ** UTF-8.
- */
- int sqlite3_complete16(const void *zSql){
- sqlite3_value *pVal;
- char const *zSql8;
- int rc = SQLITE_NOMEM;
- pVal = sqlite3ValueNew(0);
- sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
- zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
- if( zSql8 ){
- rc = sqlite3_complete(zSql8);
- }
- sqlite3ValueFree(pVal);
- return sqlite3ApiExit(0, rc);
- }
- #endif /* SQLITE_OMIT_UTF16 */
- #endif /* SQLITE_OMIT_COMPLETE */