/*

 ** 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.

 **

 ** $Id$

 */

 #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.

 */

 static int getToken(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 = TK_ID;

       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( (c=z[1])=='\'' || c=='"' ){

         int delim = c;

         *tokenType = TK_BLOB;

         for(i=2; (c=z[i])!=0; i++){

           if( c==delim ){

             if( i%2 ) *tokenType = TK_ILLEGAL;

             break;

           }

           if( !isxdigit(c) ){

             *tokenType = TK_ILLEGAL;

             return i;

           }

         }

         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;

 }

 int sqlite3GetToken(const unsigned char *z, int *tokenType){

   return getToken(z, tokenType);

 }

 /*

 ** 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;

   if( db->activeVdbeCnt==0 ){

     db->u1.isInterrupted = 0;

   }

   pParse->rc = SQLITE_OK;

   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 );

   pParse->zTail = pParse->zSql = zSql;

   while( !db->mallocFailed && zSql[i]!=0 ){

     assert( i>=0 );

     pParse->sLastToken.z = (u8*)&zSql[i];

     assert( pParse->sLastToken.dyn==0 );

     pParse->sLastToken.n = getToken((unsigned char*)&zSql[i],&tokenType);

     i += pParse->sLastToken.n;

     if( i>SQLITE_MAX_SQL_LENGTH ){

       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;

     if( !nErr ) 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;

 }