tokenize.c
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上传日期:2022-01-25
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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 splits an SQL input string up into
- ** individual tokens and sends those tokens one-by-one over to the
- ** parser for analysis.
- **
- ** $Id: tokenize.c,v 1.141 2008/04/05 18:41:43 drh Exp $
- */
- #include "sqliteInt.h"
- #include <ctype.h>
- #include <stdlib.h>
- /*
- ** The charMap() macro maps alphabetic characters into their
- ** lower-case ASCII equivalent. On ASCII machines, this is just
- ** an upper-to-lower case map. On EBCDIC machines we also need
- ** to adjust the encoding. Only alphabetic characters and underscores
- ** need to be translated.
- */
- #ifdef SQLITE_ASCII
- # define charMap(X) sqlite3UpperToLower[(unsigned char)X]
- #endif
- #ifdef SQLITE_EBCDIC
- # define charMap(X) ebcdicToAscii[(unsigned char)X]
- const unsigned char ebcdicToAscii[] = {
- /* 0 1 2 3 4 5 6 7 8 9 A B C D E F */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 1x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 2x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 3x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 4x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 5x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 95, 0, 0, /* 6x */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 7x */
- 0, 97, 98, 99,100,101,102,103,104,105, 0, 0, 0, 0, 0, 0, /* 8x */
- 0,106,107,108,109,110,111,112,113,114, 0, 0, 0, 0, 0, 0, /* 9x */
- 0, 0,115,116,117,118,119,120,121,122, 0, 0, 0, 0, 0, 0, /* Ax */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* Bx */
- 0, 97, 98, 99,100,101,102,103,104,105, 0, 0, 0, 0, 0, 0, /* Cx */
- 0,106,107,108,109,110,111,112,113,114, 0, 0, 0, 0, 0, 0, /* Dx */
- 0, 0,115,116,117,118,119,120,121,122, 0, 0, 0, 0, 0, 0, /* Ex */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* Fx */
- };
- #endif
- /*
- ** The sqlite3KeywordCode function looks up an identifier to determine if
- ** it is a keyword. If it is a keyword, the token code of that keyword is
- ** returned. If the input is not a keyword, TK_ID is returned.
- **
- ** The implementation of this routine was generated by a program,
- ** mkkeywordhash.h, located in the tool subdirectory of the distribution.
- ** The output of the mkkeywordhash.c program is written into a file
- ** named keywordhash.h and then included into this source file by
- ** the #include below.
- */
- #include "keywordhash.h"
- /*
- ** If X is a character that can be used in an identifier then
- ** IdChar(X) will be true. Otherwise it is false.
- **
- ** For ASCII, any character with the high-order bit set is
- ** allowed in an identifier. For 7-bit characters,
- ** sqlite3IsIdChar[X] must be 1.
- **
- ** For EBCDIC, the rules are more complex but have the same
- ** end result.
- **
- ** Ticket #1066. the SQL standard does not allow '$' in the
- ** middle of identfiers. But many SQL implementations do.
- ** SQLite will allow '$' in identifiers for compatibility.
- ** But the feature is undocumented.
- */
- #ifdef SQLITE_ASCII
- const char sqlite3IsAsciiIdChar[] = {
- /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
- 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 2x */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 3x */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 4x */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 5x */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6x */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 7x */
- };
- #define IdChar(C) (((c=C)&0x80)!=0 || (c>0x1f && sqlite3IsAsciiIdChar[c-0x20]))
- #endif
- #ifdef SQLITE_EBCDIC
- const char sqlite3IsEbcdicIdChar[] = {
- /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
- 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 4x */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, /* 5x */
- 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, /* 6x */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, /* 7x */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, /* 8x */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, /* 9x */
- 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, /* Ax */
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* Bx */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, /* Cx */
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, /* Dx */
- 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, /* Ex */
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, /* Fx */
- };
- #define IdChar(C) (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
- #endif
- /*
- ** Return the length of the token that begins at z[0].
- ** Store the token type in *tokenType before returning.
- */
- int sqlite3GetToken(const unsigned char *z, int *tokenType){
- int i, c;
- switch( *z ){
- case ' ': case 't': case 'n': case 'f': case 'r': {
- for(i=1; isspace(z[i]); i++){}
- *tokenType = TK_SPACE;
- return i;
- }
- case '-': {
- if( z[1]=='-' ){
- for(i=2; (c=z[i])!=0 && c!='n'; i++){}
- *tokenType = TK_COMMENT;
- return i;
- }
- *tokenType = TK_MINUS;
- return 1;
- }
- case '(': {
- *tokenType = TK_LP;
- return 1;
- }
- case ')': {
- *tokenType = TK_RP;
- return 1;
- }
- case ';': {
- *tokenType = TK_SEMI;
- return 1;
- }
- case '+': {
- *tokenType = TK_PLUS;
- return 1;
- }
- case '*': {
- *tokenType = TK_STAR;
- return 1;
- }
- case '/': {
- if( z[1]!='*' || z[2]==0 ){
- *tokenType = TK_SLASH;
- return 1;
- }
- for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
- if( c ) i++;
- *tokenType = TK_COMMENT;
- return i;
- }
- case '%': {
- *tokenType = TK_REM;
- return 1;
- }
- case '=': {
- *tokenType = TK_EQ;
- return 1 + (z[1]=='=');
- }
- case '<': {
- if( (c=z[1])=='=' ){
- *tokenType = TK_LE;
- return 2;
- }else if( c=='>' ){
- *tokenType = TK_NE;
- return 2;
- }else if( c=='<' ){
- *tokenType = TK_LSHIFT;
- return 2;
- }else{
- *tokenType = TK_LT;
- return 1;
- }
- }
- case '>': {
- if( (c=z[1])=='=' ){
- *tokenType = TK_GE;
- return 2;
- }else if( c=='>' ){
- *tokenType = TK_RSHIFT;
- return 2;
- }else{
- *tokenType = TK_GT;
- return 1;
- }
- }
- case '!': {
- if( z[1]!='=' ){
- *tokenType = TK_ILLEGAL;
- return 2;
- }else{
- *tokenType = TK_NE;
- return 2;
- }
- }
- case '|': {
- if( z[1]!='|' ){
- *tokenType = TK_BITOR;
- return 1;
- }else{
- *tokenType = TK_CONCAT;
- return 2;
- }
- }
- case ',': {
- *tokenType = TK_COMMA;
- return 1;
- }
- case '&': {
- *tokenType = TK_BITAND;
- return 1;
- }
- case '~': {
- *tokenType = TK_BITNOT;
- return 1;
- }
- case '`':
- case ''':
- case '"': {
- int delim = z[0];
- for(i=1; (c=z[i])!=0; i++){
- if( c==delim ){
- if( z[i+1]==delim ){
- i++;
- }else{
- break;
- }
- }
- }
- if( c ){
- *tokenType = TK_STRING;
- return i+1;
- }else{
- *tokenType = TK_ILLEGAL;
- return i;
- }
- }
- case '.': {
- #ifndef SQLITE_OMIT_FLOATING_POINT
- if( !isdigit(z[1]) )
- #endif
- {
- *tokenType = TK_DOT;
- return 1;
- }
- /* If the next character is a digit, this is a floating point
- ** number that begins with ".". Fall thru into the next case */
- }
- case '0': case '1': case '2': case '3': case '4':
- case '5': case '6': case '7': case '8': case '9': {
- *tokenType = TK_INTEGER;
- for(i=0; isdigit(z[i]); i++){}
- #ifndef SQLITE_OMIT_FLOATING_POINT
- if( z[i]=='.' ){
- i++;
- while( isdigit(z[i]) ){ i++; }
- *tokenType = TK_FLOAT;
- }
- if( (z[i]=='e' || z[i]=='E') &&
- ( isdigit(z[i+1])
- || ((z[i+1]=='+' || z[i+1]=='-') && isdigit(z[i+2]))
- )
- ){
- i += 2;
- while( isdigit(z[i]) ){ i++; }
- *tokenType = TK_FLOAT;
- }
- #endif
- while( IdChar(z[i]) ){
- *tokenType = TK_ILLEGAL;
- i++;
- }
- return i;
- }
- case '[': {
- for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
- *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
- return i;
- }
- case '?': {
- *tokenType = TK_VARIABLE;
- for(i=1; isdigit(z[i]); i++){}
- return i;
- }
- case '#': {
- for(i=1; isdigit(z[i]); i++){}
- if( i>1 ){
- /* Parameters of the form #NNN (where NNN is a number) are used
- ** internally by sqlite3NestedParse. */
- *tokenType = TK_REGISTER;
- return i;
- }
- /* Fall through into the next case if the '#' is not followed by
- ** a digit. Try to match #AAAA where AAAA is a parameter name. */
- }
- #ifndef SQLITE_OMIT_TCL_VARIABLE
- case '$':
- #endif
- case '@': /* For compatibility with MS SQL Server */
- case ':': {
- int n = 0;
- *tokenType = TK_VARIABLE;
- for(i=1; (c=z[i])!=0; i++){
- if( IdChar(c) ){
- n++;
- #ifndef SQLITE_OMIT_TCL_VARIABLE
- }else if( c=='(' && n>0 ){
- do{
- i++;
- }while( (c=z[i])!=0 && !isspace(c) && c!=')' );
- if( c==')' ){
- i++;
- }else{
- *tokenType = TK_ILLEGAL;
- }
- break;
- }else if( c==':' && z[i+1]==':' ){
- i++;
- #endif
- }else{
- break;
- }
- }
- if( n==0 ) *tokenType = TK_ILLEGAL;
- return i;
- }
- #ifndef SQLITE_OMIT_BLOB_LITERAL
- case 'x': case 'X': {
- if( z[1]==''' ){
- *tokenType = TK_BLOB;
- for(i=2; (c=z[i])!=0 && c!='''; i++){
- if( !isxdigit(c) ){
- *tokenType = TK_ILLEGAL;
- }
- }
- if( i%2 || !c ) *tokenType = TK_ILLEGAL;
- if( c ) i++;
- return i;
- }
- /* Otherwise fall through to the next case */
- }
- #endif
- default: {
- if( !IdChar(*z) ){
- break;
- }
- for(i=1; IdChar(z[i]); i++){}
- *tokenType = keywordCode((char*)z, i);
- return i;
- }
- }
- *tokenType = TK_ILLEGAL;
- return 1;
- }
- /*
- ** Run the parser on the given SQL string. The parser structure is
- ** passed in. An SQLITE_ status code is returned. If an error occurs
- ** and pzErrMsg!=NULL then an error message might be written into
- ** memory obtained from sqlite3_malloc() and *pzErrMsg made to point to that
- ** error message. Or maybe not.
- */
- int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
- int nErr = 0;
- int i;
- void *pEngine;
- int tokenType;
- int lastTokenParsed = -1;
- sqlite3 *db = pParse->db;
- int mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
- if( db->activeVdbeCnt==0 ){
- db->u1.isInterrupted = 0;
- }
- pParse->rc = SQLITE_OK;
- pParse->zTail = pParse->zSql = zSql;
- i = 0;
- pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3_malloc);
- if( pEngine==0 ){
- db->mallocFailed = 1;
- return SQLITE_NOMEM;
- }
- assert( pParse->sLastToken.dyn==0 );
- assert( pParse->pNewTable==0 );
- assert( pParse->pNewTrigger==0 );
- assert( pParse->nVar==0 );
- assert( pParse->nVarExpr==0 );
- assert( pParse->nVarExprAlloc==0 );
- assert( pParse->apVarExpr==0 );
- while( !db->mallocFailed && zSql[i]!=0 ){
- assert( i>=0 );
- pParse->sLastToken.z = (u8*)&zSql[i];
- assert( pParse->sLastToken.dyn==0 );
- pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
- i += pParse->sLastToken.n;
- if( i>mxSqlLen ){
- pParse->rc = SQLITE_TOOBIG;
- break;
- }
- switch( tokenType ){
- case TK_SPACE:
- case TK_COMMENT: {
- if( db->u1.isInterrupted ){
- pParse->rc = SQLITE_INTERRUPT;
- sqlite3SetString(pzErrMsg, "interrupt", (char*)0);
- goto abort_parse;
- }
- break;
- }
- case TK_ILLEGAL: {
- if( pzErrMsg ){
- sqlite3_free(*pzErrMsg);
- *pzErrMsg = sqlite3MPrintf(db, "unrecognized token: "%T"",
- &pParse->sLastToken);
- }
- nErr++;
- goto abort_parse;
- }
- case TK_SEMI: {
- pParse->zTail = &zSql[i];
- /* Fall thru into the default case */
- }
- default: {
- sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
- lastTokenParsed = tokenType;
- if( pParse->rc!=SQLITE_OK ){
- goto abort_parse;
- }
- break;
- }
- }
- }
- abort_parse:
- if( zSql[i]==0 && nErr==0 && pParse->rc==SQLITE_OK ){
- if( lastTokenParsed!=TK_SEMI ){
- sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
- pParse->zTail = &zSql[i];
- }
- sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
- }
- sqlite3ParserFree(pEngine, sqlite3_free);
- if( db->mallocFailed ){
- pParse->rc = SQLITE_NOMEM;
- }
- if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
- sqlite3SetString(&pParse->zErrMsg, sqlite3ErrStr(pParse->rc), (char*)0);
- }
- if( pParse->zErrMsg ){
- if( pzErrMsg && *pzErrMsg==0 ){
- *pzErrMsg = pParse->zErrMsg;
- }else{
- sqlite3_free(pParse->zErrMsg);
- }
- pParse->zErrMsg = 0;
- nErr++;
- }
- if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
- sqlite3VdbeDelete(pParse->pVdbe);
- pParse->pVdbe = 0;
- }
- #ifndef SQLITE_OMIT_SHARED_CACHE
- if( pParse->nested==0 ){
- sqlite3_free(pParse->aTableLock);
- pParse->aTableLock = 0;
- pParse->nTableLock = 0;
- }
- #endif
- if( !IN_DECLARE_VTAB ){
- /* If the pParse->declareVtab flag is set, do not delete any table
- ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
- ** will take responsibility for freeing the Table structure.
- */
- sqlite3DeleteTable(pParse->pNewTable);
- }
- sqlite3DeleteTrigger(pParse->pNewTrigger);
- sqlite3_free(pParse->apVarExpr);
- if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
- pParse->rc = SQLITE_ERROR;
- }
- return nErr;
- }