/* ** 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. ** ************************************************************************* ** A 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. */ #include #include #include #include "query.h" #include "sql-parser.h" /* ** All the keywords of the SQL language are stored as in a hash ** table composed of instances of the following structure. */ typedef struct Keyword Keyword; struct Keyword { const char *zName; /* The keyword name */ int tokenType; /* The token value for this keyword */ }; #define MAX_TOKEN_LEN 11 /* ** These are the keywords ** They MUST be in alphabetical order */ static const Keyword aKeywordTable[] = { { "ADD", TK_ADD }, { "ALTER", TK_ALTER }, { "AND", TK_AND }, { "BY", TK_BY }, { "CHAR", TK_CHAR }, { "CHARACTER", TK_CHAR }, { "CREATE", TK_CREATE }, { "DELETE", TK_DELETE }, { "DISTINCT", TK_DISTINCT }, { "DROP", TK_DROP }, { "FREE", TK_FREE }, { "FROM", TK_FROM }, { "HOLD", TK_HOLD }, { "INSERT", TK_INSERT }, { "INT", TK_INT }, { "INTEGER", TK_INT }, { "INTO", TK_INTO }, { "IS", TK_IS }, { "KEY", TK_KEY }, { "LIKE", TK_LIKE }, { "LOCALIZABLE", TK_LOCALIZABLE }, { "LONG", TK_LONG }, { "LONGCHAR", TK_LONGCHAR }, { "NOT", TK_NOT }, { "NULL", TK_NULL }, { "OBJECT", TK_OBJECT }, { "OR", TK_OR }, { "ORDER", TK_ORDER }, { "PRIMARY", TK_PRIMARY }, { "SELECT", TK_SELECT }, { "SET", TK_SET }, { "SHORT", TK_SHORT }, { "TABLE", TK_TABLE }, { "TEMPORARY", TK_TEMPORARY }, { "UPDATE", TK_UPDATE }, { "VALUES", TK_VALUES }, { "WHERE", TK_WHERE }, }; #define KEYWORD_COUNT ( sizeof aKeywordTable/sizeof (Keyword) ) /* ** Comparison function for binary search. */ G_GNUC_PURE static int sql_compare_keyword(const void *m1, const void *m2){ const char *p = m1; const Keyword *k = m2; const char *q = k->zName; for (; *p; p++, q++) { char c; if ((uint16_t) *p > 127) return 1; c = *p; if (c >= 'a' && c <= 'z') c ^= 'A' ^ 'a'; if (c != *q) return (unsigned)c - (unsigned)*q; } return (unsigned)*p - (unsigned)*q; } /* ** This 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. */ static int sqlite_find_keyword(const char *z, int n){ char str[MAX_TOKEN_LEN+1]; Keyword *r; if( n>MAX_TOKEN_LEN ) return TK_ID; memcpy( str, z, n*sizeof (char) ); str[n] = 0; r = bsearch( str, aKeywordTable, KEYWORD_COUNT, sizeof (Keyword), sql_compare_keyword ); if( r ) return r->tokenType; return TK_ID; } /* ** If X is a character that can be used in an identifier then ** isIdChar[X] will be 1. Otherwise isIdChar[X] will be 0. ** ** In this implementation, an identifier can be a string of ** alphabetic characters, digits, and "_" plus any character ** with the high-order bit set. The latter rule means that ** any sequence of UTF-8 characters or characters taken from ** an extended ISO8859 character set can form an identifier. */ static const char isIdChar[] = { /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */ 0, 0, 0, 0, 0, 1, 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, 1, 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 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 8x */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 9x */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* Ax */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* Bx */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* Cx */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* Dx */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* Ex */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* Fx */ }; /* ** Return the length of the token that begins at z[0]. Return ** -1 if the token is (or might be) incomplete. Store the token ** type in *tokenType before returning. */ int sql_get_token(const char *zz, int *tokenType, int *skip){ guint8 *z = (guint8*)zz; int i; *skip = 0; switch( *z ){ case ' ': case '\t': case '\n': case '\f': for(i=1; isspace(z[i]) && z[i] != '\r'; i++){} *tokenType = TK_SPACE; return i; case '-': if( z[1]==0 ) return -1; *tokenType = TK_MINUS; return 1; case '(': *tokenType = TK_LP; return 1; case ')': *tokenType = TK_RP; return 1; case '*': *tokenType = TK_STAR; return 1; case '=': *tokenType = TK_EQ; return 1; case '<': if( z[1]=='=' ){ *tokenType = TK_LE; return 2; }else if( z[1]=='>' ){ *tokenType = TK_NE; return 2; }else{ *tokenType = TK_LT; return 1; } case '>': if( z[1]=='=' ){ *tokenType = TK_GE; return 2; }else{ *tokenType = TK_GT; return 1; } case '!': if( z[1]!='=' ){ *tokenType = TK_ILLEGAL; return 2; }else{ *tokenType = TK_NE; return 2; } case '?': *tokenType = TK_WILDCARD; return 1; case ',': *tokenType = TK_COMMA; return 1; case '`': case '\'': { int delim = z[0]; for(i=1; z[i]; i++){ if( z[i]==delim ) break; } if( z[i] ) i++; if( delim == '`' ) *tokenType = TK_ID; else *tokenType = TK_STRING; return i; } case '.': if( !isdigit(z[1]) ){ *tokenType = TK_DOT; return 1; } /* Fall through */ 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=1; isdigit(z[i]); i++){} return i; case '[': for(i=1; z[i] && z[i-1]!=']'; i++){} *tokenType = TK_ID; return i; default: if( !isIdChar[*z] ){ break; } for(i=1; isIdChar[z[i]]; i++){} *tokenType = sqlite_find_keyword(zz, i); if( *tokenType == TK_ID && z[i] == '`' ) *skip = 1; return i; } *tokenType = TK_ILLEGAL; return 1; }