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sqlite/src/tokenize.c
drh 9bbca4c1c0 Implement indices that occur in sort order and the LIMIT...OFFSET clause 
of SELECT statements. (CVS 301)

FossilOrigin-Name: eb07768ae93f14bf6c150c1c4329948857a9d01c
2001-11-06 04:00:18 +00:00

450 lines
14 KiB
C
Raw Blame History

/*
** 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 1.32 2001/11/06 04:00:19 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.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 {
char *zName; /* The keyword name */
int len; /* Number of characters in the keyword */
int tokenType; /* The token value for this keyword */
Keyword *pNext; /* Next keyword with the same hash */
};
/*
** These are the keywords
*/
static Keyword aKeywordTable[] = {
{ "ALL", 0, TK_ALL, 0 },
{ "AND", 0, TK_AND, 0 },
{ "AS", 0, TK_AS, 0 },
{ "ASC", 0, TK_ASC, 0 },
{ "BEGIN", 0, TK_BEGIN, 0 },
{ "BETWEEN", 0, TK_BETWEEN, 0 },
{ "BY", 0, TK_BY, 0 },
{ "CHECK", 0, TK_CHECK, 0 },
{ "CLUSTER", 0, TK_CLUSTER, 0 },
{ "COMMIT", 0, TK_COMMIT, 0 },
{ "CONSTRAINT", 0, TK_CONSTRAINT, 0 },
{ "COPY", 0, TK_COPY, 0 },
{ "CREATE", 0, TK_CREATE, 0 },
{ "DEFAULT", 0, TK_DEFAULT, 0 },
{ "DELETE", 0, TK_DELETE, 0 },
{ "DELIMITERS", 0, TK_DELIMITERS, 0 },
{ "DESC", 0, TK_DESC, 0 },
{ "DISTINCT", 0, TK_DISTINCT, 0 },
{ "DROP", 0, TK_DROP, 0 },
{ "END", 0, TK_END, 0 },
{ "EXCEPT", 0, TK_EXCEPT, 0 },
{ "EXPLAIN", 0, TK_EXPLAIN, 0 },
{ "FROM", 0, TK_FROM, 0 },
{ "GLOB", 0, TK_GLOB, 0 },
{ "GROUP", 0, TK_GROUP, 0 },
{ "HAVING", 0, TK_HAVING, 0 },
{ "IN", 0, TK_IN, 0 },
{ "INDEX", 0, TK_INDEX, 0 },
{ "INSERT", 0, TK_INSERT, 0 },
{ "INTERSECT", 0, TK_INTERSECT, 0 },
{ "INTO", 0, TK_INTO, 0 },
{ "IS", 0, TK_IS, 0 },
{ "ISNULL", 0, TK_ISNULL, 0 },
{ "KEY", 0, TK_KEY, 0 },
{ "LIKE", 0, TK_LIKE, 0 },
{ "LIMIT", 0, TK_LIMIT, 0 },
{ "NOT", 0, TK_NOT, 0 },
{ "NOTNULL", 0, TK_NOTNULL, 0 },
{ "NULL", 0, TK_NULL, 0 },
{ "OFFSET", 0, TK_OFFSET, 0 },
{ "ON", 0, TK_ON, 0 },
{ "OR", 0, TK_OR, 0 },
{ "ORDER", 0, TK_ORDER, 0 },
{ "PRAGMA", 0, TK_PRAGMA, 0 },
{ "PRIMARY", 0, TK_PRIMARY, 0 },
{ "ROLLBACK", 0, TK_ROLLBACK, 0 },
{ "SELECT", 0, TK_SELECT, 0 },
{ "SET", 0, TK_SET, 0 },
{ "TABLE", 0, TK_TABLE, 0 },
{ "TEMP", 0, TK_TEMP, 0 },
{ "TEMPORARY", 0, TK_TEMP, 0 },
{ "TRANSACTION", 0, TK_TRANSACTION, 0 },
{ "UNION", 0, TK_UNION, 0 },
{ "UNIQUE", 0, TK_UNIQUE, 0 },
{ "UPDATE", 0, TK_UPDATE, 0 },
{ "USING", 0, TK_USING, 0 },
{ "VACUUM", 0, TK_VACUUM, 0 },
{ "VALUES", 0, TK_VALUES, 0 },
{ "WHERE", 0, TK_WHERE, 0 },
};
/*
** This is the hash table
*/
#define KEY_HASH_SIZE 71
static Keyword *apHashTable[KEY_HASH_SIZE];
/*
** 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 sqliteKeywordCode(const char *z, int n){
int h;
Keyword *p;
if( aKeywordTable[0].len==0 ){
/* Initialize the keyword hash table */
sqliteOsEnterMutex();
if( aKeywordTable[0].len==0 ){
int i;
int n;
n = sizeof(aKeywordTable)/sizeof(aKeywordTable[0]);
for(i=0; i<n; i++){
aKeywordTable[i].len = strlen(aKeywordTable[i].zName);
h = sqliteHashNoCase(aKeywordTable[i].zName, aKeywordTable[i].len);
h %= KEY_HASH_SIZE;
aKeywordTable[i].pNext = apHashTable[h];
apHashTable[h] = &aKeywordTable[i];
}
}
sqliteOsLeaveMutex();
}
h = sqliteHashNoCase(z, n) % KEY_HASH_SIZE;
for(p=apHashTable[h]; p; p=p->pNext){
if( p->len==n && sqliteStrNICmp(p->zName, z, n)==0 ){
return p->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, 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 */
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.
*/
static int sqliteGetToken(const unsigned char *z, int *tokenType){
int i;
switch( *z ){
case ' ': case '\t': case '\n': case '\f': case '\r': {
for(i=1; z[i] && isspace(z[i]); i++){}
*tokenType = TK_SPACE;
return i;
}
case '-': {
if( z[1]==0 ) return -1;
if( z[1]=='-' ){
for(i=2; z[i] && z[i]!='\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 '/': {
*tokenType = TK_SLASH;
return 1;
}
case '%': {
*tokenType = TK_REM;
return 1;
}
case '=': {
*tokenType = TK_EQ;
return 1 + (z[1]=='=');
}
case '<': {
if( z[1]=='=' ){
*tokenType = TK_LE;
return 2;
}else if( z[1]=='>' ){
*tokenType = TK_NE;
return 2;
}else if( z[1]=='<' ){
*tokenType = TK_LSHIFT;
return 2;
}else{
*tokenType = TK_LT;
return 1;
}
}
case '>': {
if( z[1]=='=' ){
*tokenType = TK_GE;
return 2;
}else if( z[1]=='>' ){
*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 '"': {
int delim = z[0];
for(i=1; z[i]; i++){
if( z[i]==delim ){
if( z[i+1]==delim ){
i++;
}else{
break;
}
}
}
if( z[i] ) i++;
*tokenType = TK_STRING;
return i;
}
case '.': {
if( !isdigit(z[1]) ){
*tokenType = TK_DOT;
return 1;
}
/* 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=1; z[i] && isdigit(z[i]); i++){}
if( z[i]=='.' ){
i++;
while( z[i] && 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( z[i] && isdigit(z[i]) ){ i++; }
*tokenType = TK_FLOAT;
}else if( z[0]=='.' ){
*tokenType = TK_FLOAT;
}
return i;
}
default: {
if( !isIdChar[*z] ){
break;
}
for(i=1; isIdChar[z[i]]; i++){}
*tokenType = sqliteKeywordCode((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 malloc() and *pzErrMsg made to point to that
** error message. Or maybe not.
*/
int sqliteRunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
int nErr = 0;
int i;
void *pEngine;
int once = 1;
sqlite *db = pParse->db;
extern void *sqliteParserAlloc(void*(*)(int));
extern void sqliteParserFree(void*, void(*)(void*));
extern int sqliteParser(void*, int, Token, Parse*);
db->flags &= ~SQLITE_Interrupt;
pParse->rc = SQLITE_OK;
i = 0;
sqliteParseInfoReset(pParse);
pEngine = sqliteParserAlloc((void*(*)(int))malloc);
if( pEngine==0 ){
sqliteSetString(pzErrMsg, "out of memory", 0);
return 1;
}
while( sqlite_malloc_failed==0 && nErr==0 && i>=0 && zSql[i]!=0 ){
int tokenType;
if( (db->flags & SQLITE_Interrupt)!=0 ){
pParse->rc = SQLITE_INTERRUPT;
sqliteSetString(pzErrMsg, "interrupt", 0);
break;
}
pParse->sLastToken.z = &zSql[i];
pParse->sLastToken.n = sqliteGetToken((unsigned char*)&zSql[i], &tokenType);
i += pParse->sLastToken.n;
if( once ){
pParse->sFirstToken = pParse->sLastToken;
once = 0;
}
switch( tokenType ){
case TK_SPACE:
case TK_COMMENT: {
break;
}
case TK_ILLEGAL:
sqliteSetNString(pzErrMsg, "unrecognized token: \"", -1,
pParse->sLastToken.z, pParse->sLastToken.n, "\"", 1, 0);
nErr++;
break;
default:
sqliteParser(pEngine, tokenType, pParse->sLastToken, pParse);
if( pParse->zErrMsg && pParse->sErrToken.z ){
sqliteSetNString(pzErrMsg, "near \"", -1,
pParse->sErrToken.z, pParse->sErrToken.n,
"\": ", -1,
pParse->zErrMsg, -1,
0);
nErr++;
sqliteFree(pParse->zErrMsg);
pParse->zErrMsg = 0;
}else if( pParse->rc!=SQLITE_OK ){
sqliteSetString(pzErrMsg, sqlite_error_string(pParse->rc), 0);
nErr++;
}
break;
}
}
if( nErr==0 && (db->flags & SQLITE_Interrupt)==0 ){
sqliteParser(pEngine, 0, pParse->sLastToken, pParse);
if( pParse->zErrMsg && pParse->sErrToken.z ){
sqliteSetNString(pzErrMsg, "near \"", -1,
pParse->sErrToken.z, pParse->sErrToken.n,
"\": ", -1,
pParse->zErrMsg, -1,
0);
nErr++;
sqliteFree(pParse->zErrMsg);
pParse->zErrMsg = 0;
}
}
sqliteParserFree(pEngine, free);
if( pParse->zErrMsg ){
if( pzErrMsg ){
sqliteFree(*pzErrMsg);
*pzErrMsg = pParse->zErrMsg;
}else{
sqliteFree(pParse->zErrMsg);
}
if( !nErr ) nErr++;
}
if( pParse->pVdbe ){
sqliteVdbeDelete(pParse->pVdbe);
pParse->pVdbe = 0;
}
if( pParse->pNewTable ){
sqliteDeleteTable(pParse->db, pParse->pNewTable);
pParse->pNewTable = 0;
}
sqliteParseInfoReset(pParse);
if( nErr>0 && pParse->rc==SQLITE_OK ){
pParse->rc = SQLITE_ERROR;
}
return nErr;
}
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