static void renameParentFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
sqlite3 *db = sqlite3_context_db_handle(context);
char *zOutput = 0;
char *zResult;
unsigned char const *zInput = sqlite3_value_text(argv[0]);
unsigned char const *zOld = sqlite3_value_text(argv[1]);
unsigned char const *zNew = sqlite3_value_text(argv[2]);
unsigned const char *z; /* Pointer to token */
int n; /* Length of token z */
int token; /* Type of token */
UNUSED_PARAMETER(NotUsed);
if( zInput==0 || zOld==0 ) return;
for(z=zInput; *z; z=z+n){
n = sqlite3GetToken(z, &token);
if( token==TK_REFERENCES ){
char *zParent;
do {
z += n;
n = sqlite3GetToken(z, &token);
}while( token==TK_SPACE );
if( token==TK_ILLEGAL ) break;
zParent = sqlite3DbStrNDup(db, (const char *)z, n);
if( zParent==0 ) break;
sqlite3Dequote(zParent);
if( 0==sqlite3StrICmp((const char *)zOld, zParent) ){
char *zOut = sqlite3MPrintf(db, "%s%.*s\"%w\"",
(zOutput?zOutput:""), (int)(z-zInput), zInput, (const char *)zNew
);
sqlite3DbFree(db, zOutput);
zOutput = zOut;
zInput = &z[n];
}
sqlite3DbFree(db, zParent);
}
}
zResult = sqlite3MPrintf(db, "%s%s", (zOutput?zOutput:""), zInput),
sqlite3_result_text(context, zResult, -1, SQLITE_DYNAMIC);
sqlite3DbFree(db, zOutput);
}
/* This function is used by SQL generated to implement the ALTER TABLE
** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER
** statement. The second is a table name. The table name in the CREATE
** TRIGGER statement is replaced with the second argument and the result
** returned. This is analagous to renameTableFunc() above, except for CREATE
** TRIGGER, not CREATE INDEX and CREATE TABLE.
*/
static void renameTriggerFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
unsigned char const *zSql = sqlite3_value_text(argv[0]);
unsigned char const *zTableName = sqlite3_value_text(argv[1]);
int token;
Token tname;
int dist = 3;
unsigned char const *zCsr = zSql;
int len = 0;
char *zRet;
/* The principle used to locate the table name in the CREATE TRIGGER
** statement is that the table name is the first token that is immediatedly
** preceded by either TK_ON or TK_DOT and immediatedly followed by one
** of TK_WHEN, TK_BEGIN or TK_FOR.
*/
if( zSql ){
do {
/* Store the token that zCsr points to in tname. */
tname.z = zCsr;
tname.n = len;
/* Advance zCsr to the next token. Store that token type in 'token',
** and it's length in 'len' (to be used next iteration of this loop).
*/
do {
zCsr += len;
len = sqlite3GetToken(zCsr, &token);
}while( token==TK_SPACE );
assert( len>0 );
/* Variable 'dist' stores the number of tokens read since the most
** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN
** token is read and 'dist' equals 2, the condition stated above
** to be met.
**
** Note that ON cannot be a database, table or column name, so
** there is no need to worry about syntax like
** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc.
*/
dist++;
if( token==TK_DOT || token==TK_ON ){
dist = 0;
}
} while( dist!=2 || (token!=TK_WHEN && token!=TK_FOR && token!=TK_BEGIN) );
/* Variable tname now contains the token that is the old table-name
** in the CREATE TRIGGER statement.
*/
zRet = sqlite3MPrintf("%.*s%Q%s", tname.z - zSql, zSql,
zTableName, tname.z+tname.n);
sqlite3_result_text(context, zRet, -1, sqlite3FreeX);
}
}
/*
** This function is used by SQL generated to implement the
** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
** CREATE INDEX command. The second is a table name. The table name in
** the CREATE TABLE or CREATE INDEX statement is replaced with the third
** argument and the result returned. Examples:
**
** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
** -> 'CREATE TABLE def(a, b, c)'
**
** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
** -> 'CREATE INDEX i ON def(a, b, c)'
这个函数使用SQL执行ALTER TABLE命令生成。
第一个参数是创建表或文本
创建索引的命令。第二个是表名。
创建表的表名或创建INDEX语句被替换为第三个参数,返回的结果。
例子:
** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
** -> 'CREATE TABLE def(a, b, c)'
**
** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
** -> 'CREATE INDEX i ON def(a, b, c)'
*/
static void renameTableFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
unsigned char const *zSql = sqlite3_value_text(argv[0]);
unsigned char const *zTableName = sqlite3_value_text(argv[1]);
int token;
Token tname;
unsigned char const *zCsr = zSql;
int len = 0;
char *zRet;
sqlite3 *db = sqlite3_context_db_handle(context);
UNUSED_PARAMETER(NotUsed);
/* The principle used to locate the table name in the CREATE TABLE
** statement is that the table name is the first non-space token that
** is immediately followed by a TK_LP or TK_USING token.
原理用于定位在CREATE table语句表名,
该语句是表名是立即紧随其后TK_LP或进行技术改造TK_USING令牌的第一个非空间令牌。
*/
if( zSql ){
do {
if( !*zCsr ){
/* Ran out of input before finding an opening bracket. Return NULL. 找到一个开括号之前放弃输入。返回null。*/
return;
}
/* Store the token that zCsr points to in tname. 存储tname zCsr指向表名的令牌 */
tname.z = (char*)zCsr;
tname.n = len;
/* Advance zCsr to the next token. Store that token type in 'token',
** and its length in 'len' (to be used next iteration of this loop).
推进zCsr到下一个令牌。令牌类型存储用“token”,
和它的长度的用‘len’(下一个迭代的循环使用)。
*/
do {
zCsr += len;
len = sqlite3GetToken(zCsr, &token);
} while( token==TK_SPACE );
assert( len>0 );
} while( token!=TK_LP && token!=TK_USING );
zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", ((u8*)tname.z) - zSql, zSql,
zTableName, tname.z+tname.n);
sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
}
}
/*
** This function is used by SQL generated to implement the
** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
** CREATE INDEX command. The second is a table name. The table name in
** the CREATE TABLE or CREATE INDEX statement is replaced with the third
** argument and the result returned. Examples:
**
** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
** -> 'CREATE TABLE def(a, b, c)'
**
** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
** -> 'CREATE INDEX i ON def(a, b, c)'
*/
static void renameTableFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
unsigned char const *zSql = sqlite3_value_text(argv[0]);
unsigned char const *zTableName = sqlite3_value_text(argv[1]);
int token;
Token tname;
unsigned char const *zCsr = zSql;
int len = 0;
char *zRet;
sqlite3 *db = sqlite3_context_db_handle(context);
UNUSED_PARAMETER(NotUsed);
/* The principle used to locate the table name in the CREATE TABLE
** statement is that the table name is the first non-space token that
** is immediately followed by a TK_LP or TK_USING token.
*/
if( zSql ){
do {
if( !*zCsr ){
/* Ran out of input before finding an opening bracket. Return NULL. */
return;
}
/* Store the token that zCsr points to in tname. */
tname.z = zCsr;
tname.n = len;
/* Advance zCsr to the next token. Store that token type in 'token',
** and its length in 'len' (to be used next iteration of this loop).
*/
do {
zCsr += len;
len = sqlite3GetToken(zCsr, &token);
} while( token==TK_SPACE );
assert( len>0 );
} while( token!=TK_LP && token!=TK_USING );
zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", tname.z - zSql, zSql,
zTableName, tname.z+tname.n);
sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
}
}
/*
** Return the id of the next token in string (*pz). Before returning, set
** (*pz) to point to the byte following the parsed token.
*/
static int getToken(const unsigned char **pz){
const unsigned char *z = *pz;
int t; /* Token type to return */
do {
z += sqlite3GetToken(z, &t);
}while( t==TK_SPACE );
if( t==TK_ID
|| t==TK_STRING
|| t==TK_JOIN_KW
|| t==TK_WINDOW
|| t==TK_OVER
|| sqlite3ParserFallback(t)==TK_ID
){
t = TK_ID;
}
*pz = z;
return t;
}
/*
** zSql is a zero-terminated string of UTF-8 SQL text. Return the number of
** bytes in this text up to but excluding the first character in
** a host parameter. If the text contains no host parameters, return
** the total number of bytes in the text.
*/
static int findNextHostParameter(const char *zSql, int *pnToken){
int tokenType;
int nTotal = 0;
int n;
*pnToken = 0;
while( zSql[0] ){
n = sqlite3GetToken((u8*)zSql, &tokenType);
assert( n>0 && tokenType!=TK_ILLEGAL );
if( tokenType==TK_VARIABLE ){
*pnToken = n;
break;
}
nTotal += n;
zSql += n;
}
return nTotal;
}
/*
** This function is used by SQL generated to implement the
** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
** CREATE INDEX command. The second is a table name. The table name in
** the CREATE TABLE or CREATE INDEX statement is replaced with the third
** argument and the result returned. Examples:
**
** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
** -> 'CREATE TABLE def(a, b, c)'
**
** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
** -> 'CREATE INDEX i ON def(a, b, c)'
*/
static void renameTableFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
unsigned char const *zSql = sqlite3_value_text(argv[0]);
unsigned char const *zTableName = sqlite3_value_text(argv[1]);
int token;
Token tname;
unsigned char const *zCsr = zSql;
int len = 0;
char *zRet;
/* The principle used to locate the table name in the CREATE TABLE
** statement is that the table name is the first token that is immediatedly
** followed by a left parenthesis - TK_LP - or "USING" TK_USING.
*/
if( zSql ){
do {
if( !*zCsr ){
/* Ran out of input before finding an opening bracket. Return NULL. */
return;
}
/* Store the token that zCsr points to in tname. */
tname.z = zCsr;
tname.n = len;
/* Advance zCsr to the next token. Store that token type in 'token',
** and it's length in 'len' (to be used next iteration of this loop).
*/
do {
zCsr += len;
len = sqlite3GetToken(zCsr, &token);
} while( token==TK_SPACE );
assert( len>0 );
} while( token!=TK_LP && token!=TK_USING );
zRet = sqlite3MPrintf("%.*s%Q%s", tname.z - zSql, zSql,
zTableName, tname.z+tname.n);
sqlite3_result_text(context, zRet, -1, sqlite3FreeX);
}
}
/*
** Run the parser on the given SQL string. The parser structure is
** passed in. An SQLITE_ status code is returned. If an error occurs
** then an and attempt is made to write an error message into
** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
** error message.
*/
int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
int nErr = 0; /* Number of errors encountered */
void *pEngine; /* The LEMON-generated LALR(1) parser */
int n = 0; /* Length of the next token token */
int tokenType; /* type of the next token */
int lastTokenParsed = -1; /* type of the previous token */
sqlite3 *db = pParse->db; /* The database connection */
int mxSqlLen; /* Max length of an SQL string */
#ifdef sqlite3Parser_ENGINEALWAYSONSTACK
yyParser sEngine; /* Space to hold the Lemon-generated Parser object */
#endif
assert( zSql!=0 );
mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
if( db->nVdbeActive==0 ){
db->u1.isInterrupted = 0;
}
pParse->rc = SQLITE_OK;
pParse->zTail = zSql;
assert( pzErrMsg!=0 );
#ifdef SQLITE_DEBUG
if( db->flags & SQLITE_ParserTrace ){
printf("parser: [[[%s]]]\n", zSql);
sqlite3ParserTrace(stdout, "parser: ");
}else{
sqlite3ParserTrace(0, 0);
}
#endif
#ifdef sqlite3Parser_ENGINEALWAYSONSTACK
pEngine = &sEngine;
sqlite3ParserInit(pEngine, pParse);
#else
pEngine = sqlite3ParserAlloc(sqlite3Malloc, pParse);
if( pEngine==0 ){
sqlite3OomFault(db);
return SQLITE_NOMEM_BKPT;
}
#endif
assert( pParse->pNewTable==0 );
assert( pParse->pNewTrigger==0 );
assert( pParse->nVar==0 );
assert( pParse->pVList==0 );
while( 1 ){
n = sqlite3GetToken((u8*)zSql, &tokenType);
mxSqlLen -= n;
if( mxSqlLen<0 ){
pParse->rc = SQLITE_TOOBIG;
break;
}
#ifndef SQLITE_OMIT_WINDOWFUNC
if( tokenType>=TK_WINDOW ){
assert( tokenType==TK_SPACE || tokenType==TK_OVER || tokenType==TK_FILTER
|| tokenType==TK_ILLEGAL || tokenType==TK_WINDOW
);
#else
if( tokenType>=TK_SPACE ){
assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
#endif /* SQLITE_OMIT_WINDOWFUNC */
if( db->u1.isInterrupted ){
pParse->rc = SQLITE_INTERRUPT;
break;
}
if( tokenType==TK_SPACE ){
zSql += n;
continue;
}
if( zSql[0]==0 ){
/* Upon reaching the end of input, call the parser two more times
** with tokens TK_SEMI and 0, in that order. */
if( lastTokenParsed==TK_SEMI ){
tokenType = 0;
}else if( lastTokenParsed==0 ){
break;
}else{
tokenType = TK_SEMI;
}
n = 0;
#ifndef SQLITE_OMIT_WINDOWFUNC
}else if( tokenType==TK_WINDOW ){
assert( n==6 );
tokenType = analyzeWindowKeyword((const u8*)&zSql[6]);
}else if( tokenType==TK_OVER ){
assert( n==4 );
tokenType = analyzeOverKeyword((const u8*)&zSql[4], lastTokenParsed);
}else if( tokenType==TK_FILTER ){
assert( n==6 );
tokenType = analyzeFilterKeyword((const u8*)&zSql[6], lastTokenParsed);
#endif /* SQLITE_OMIT_WINDOWFUNC */
}else{
sqlite3ErrorMsg(pParse, "unrecognized token: \"%.*s\"", n, zSql);
break;
}
}
pParse->sLastToken.z = zSql;
pParse->sLastToken.n = n;
sqlite3Parser(pEngine, tokenType, pParse->sLastToken);
lastTokenParsed = tokenType;
zSql += n;
if( pParse->rc!=SQLITE_OK || db->mallocFailed ) break;
}
assert( nErr==0 );
#ifdef YYTRACKMAXSTACKDEPTH
sqlite3_mutex_enter(sqlite3MallocMutex());
sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,
sqlite3ParserStackPeak(pEngine)
);
sqlite3_mutex_leave(sqlite3MallocMutex());
#endif /* YYDEBUG */
#ifdef sqlite3Parser_ENGINEALWAYSONSTACK
sqlite3ParserFinalize(pEngine);
#else
sqlite3ParserFree(pEngine, sqlite3_free);
#endif
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM_BKPT;
}
if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));
}
assert( pzErrMsg!=0 );
if( pParse->zErrMsg ){
*pzErrMsg = pParse->zErrMsg;
sqlite3_log(pParse->rc, "%s in \"%s\"",
*pzErrMsg, pParse->zTail);
pParse->zErrMsg = 0;
nErr++;
}
pParse->zTail = zSql;
if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
sqlite3VdbeDelete(pParse->pVdbe);
pParse->pVdbe = 0;
}
#ifndef SQLITE_OMIT_SHARED_CACHE
if( pParse->nested==0 ){
sqlite3DbFree(db, pParse->aTableLock);
pParse->aTableLock = 0;
pParse->nTableLock = 0;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqlite3_free(pParse->apVtabLock);
#endif
if( !IN_SPECIAL_PARSE ){
/* 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(db, pParse->pNewTable);
}
if( !IN_RENAME_OBJECT ){
sqlite3DeleteTrigger(db, pParse->pNewTrigger);
}
if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);
sqlite3DbFree(db, pParse->pVList);
while( pParse->pAinc ){
AutoincInfo *p = pParse->pAinc;
pParse->pAinc = p->pNext;
sqlite3DbFreeNN(db, p);
}
while( pParse->pZombieTab ){
Table *p = pParse->pZombieTab;
pParse->pZombieTab = p->pNextZombie;
sqlite3DeleteTable(db, p);
}
assert( nErr==0 || pParse->rc!=SQLITE_OK );
return nErr;
}
#ifdef SQLITE_ENABLE_NORMALIZE
/*
** Insert a single space character into pStr if the current string
** ends with an identifier
*/
static void addSpaceSeparator(sqlite3_str *pStr){
if( pStr->nChar && sqlite3IsIdChar(pStr->zText[pStr->nChar-1]) ){
sqlite3_str_append(pStr, " ", 1);
}
}
/*
** Compute a normalization of the SQL given by zSql[0..nSql-1]. Return
** the normalization in space obtained from sqlite3DbMalloc(). Or return
** NULL if anything goes wrong or if zSql is NULL.
*/
char *sqlite3Normalize(
Vdbe *pVdbe, /* VM being reprepared */
const char *zSql /* The original SQL string */
){
sqlite3 *db; /* The database connection */
int i; /* Next unread byte of zSql[] */
int n; /* length of current token */
int tokenType; /* type of current token */
int prevType = 0; /* Previous non-whitespace token */
int nParen; /* Number of nested levels of parentheses */
int iStartIN; /* Start of RHS of IN operator in z[] */
int nParenAtIN; /* Value of nParent at start of RHS of IN operator */
int j; /* Bytes of normalized SQL generated so far */
sqlite3_str *pStr; /* The normalized SQL string under construction */
db = sqlite3VdbeDb(pVdbe);
tokenType = -1;
nParen = iStartIN = nParenAtIN = 0;
pStr = sqlite3_str_new(db);
assert( pStr!=0 ); /* sqlite3_str_new() never returns NULL */
for(i=0; zSql[i] && pStr->accError==0; i+=n){
if( tokenType!=TK_SPACE ){
prevType = tokenType;
}
n = sqlite3GetToken((unsigned char*)zSql+i, &tokenType);
if( NEVER(n<=0) ) break;
switch( tokenType ){
case TK_SPACE: {
break;
}
case TK_NULL: {
if( prevType==TK_IS || prevType==TK_NOT ){
sqlite3_str_append(pStr, " NULL", 5);
break;
}
/* Fall through */
}
case TK_STRING:
case TK_INTEGER:
case TK_FLOAT:
case TK_VARIABLE:
case TK_BLOB: {
sqlite3_str_append(pStr, "?", 1);
break;
}
case TK_LP: {
nParen++;
if( prevType==TK_IN ){
iStartIN = pStr->nChar;
nParenAtIN = nParen;
}
sqlite3_str_append(pStr, "(", 1);
break;
}
case TK_RP: {
if( iStartIN>0 && nParen==nParenAtIN ){
assert( pStr->nChar>=iStartIN );
pStr->nChar = iStartIN+1;
sqlite3_str_append(pStr, "?,?,?", 5);
iStartIN = 0;
}
nParen--;
sqlite3_str_append(pStr, ")", 1);
break;
}
case TK_ID: {
iStartIN = 0;
j = pStr->nChar;
if( sqlite3Isquote(zSql[i]) ){
char *zId = sqlite3DbStrNDup(db, zSql+i, n);
int nId;
int eType = 0;
if( zId==0 ) break;
sqlite3Dequote(zId);
if( zSql[i]=='"' && sqlite3VdbeUsesDoubleQuotedString(pVdbe, zId) ){
sqlite3_str_append(pStr, "?", 1);
sqlite3DbFree(db, zId);
break;
}
nId = sqlite3Strlen30(zId);
if( sqlite3GetToken((u8*)zId, &eType)==nId && eType==TK_ID ){
addSpaceSeparator(pStr);
sqlite3_str_append(pStr, zId, nId);
}else{
sqlite3_str_appendf(pStr, "\"%w\"", zId);
}
sqlite3DbFree(db, zId);
}else{
addSpaceSeparator(pStr);
sqlite3_str_append(pStr, zSql+i, n);
}
while( j<pStr->nChar ){
pStr->zText[j] = sqlite3Tolower(pStr->zText[j]);
j++;
}
break;
}
case TK_SELECT: {
iStartIN = 0;
/* fall through */
}
default: {
if( sqlite3IsIdChar(zSql[i]) ) addSpaceSeparator(pStr);
j = pStr->nChar;
sqlite3_str_append(pStr, zSql+i, n);
while( j<pStr->nChar ){
pStr->zText[j] = sqlite3Toupper(pStr->zText[j]);
j++;
}
break;
}
}
}
if( tokenType!=TK_SEMI ) sqlite3_str_append(pStr, ";", 1);
return sqlite3_str_finish(pStr);
}
/*
** Run the parser on the given SQL string. The parser structure is
** passed in. An SQLITE_ status code is returned. If an error occurs
** then an and attempt is made to write an error message into
** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
** error message.
*/
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;
assert( pzErrMsg!=0 );
pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3Malloc);
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: {
if( db->u1.isInterrupted ){
pParse->rc = SQLITE_INTERRUPT;
sqlite3SetString(pzErrMsg, db, "interrupt");
goto abort_parse;
}
break;
}
case TK_ILLEGAL: {
sqlite3DbFree(db, *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);
}
#ifdef YYTRACKMAXSTACKDEPTH
sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
sqlite3ParserStackPeak(pEngine)
);
#endif /* YYDEBUG */
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, db, "%s", sqlite3ErrStr(pParse->rc));
}
if( pParse->zErrMsg ){
if( *pzErrMsg==0 ){
*pzErrMsg = pParse->zErrMsg;
}else{
sqlite3DbFree(db, 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 ){
sqlite3DbFree(db, pParse->aTableLock);
pParse->aTableLock = 0;
pParse->nTableLock = 0;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqlite3DbFree(db, pParse->apVtabLock);
#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(db, pParse->pNewTrigger);
sqlite3DbFree(db, pParse->apVarExpr);
sqlite3DbFree(db, pParse->aAlias);
if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
pParse->rc = SQLITE_ERROR;
}
return nErr;
}
/*
** Run the parser on the given SQL string. The parser structure is
** passed in. An SQLITE_ status code is returned. If an error occurs
** then an and attempt is made to write an error message into
** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
** error message.
*/
int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
int nErr = 0; /* Number of errors encountered */
int i; /* Loop counter */
void *pEngine; /* The LEMON-generated LALR(1) parser */
int tokenType; /* type of the next token */
int lastTokenParsed = -1; /* type of the previous token */
u8 enableLookaside; /* Saved value of db->lookaside.bEnabled */
sqlite3 *db = pParse->db; /* The database connection */
int mxSqlLen; /* Max length of an SQL string */
mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
if( db->activeVdbeCnt==0 ){
db->u1.isInterrupted = 0;
}
pParse->rc = SQLITE_OK;
pParse->zTail = zSql;
i = 0;
assert( pzErrMsg!=0 );
pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3Malloc);
if( pEngine==0 ){
db->mallocFailed = 1;
return SQLITE_NOMEM;
}
assert( pParse->pNewTable==0 );
assert( pParse->pNewTrigger==0 );
assert( pParse->nVar==0 );
assert( pParse->nVarExpr==0 );
assert( pParse->nVarExprAlloc==0 );
assert( pParse->apVarExpr==0 );
enableLookaside = db->lookaside.bEnabled;
if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
while( !db->mallocFailed && zSql[i]!=0 ){
assert( i>=0 );
pParse->sLastToken.z = &zSql[i];
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: {
if( db->u1.isInterrupted ){
sqlite3ErrorMsg(pParse, "interrupt");
pParse->rc = SQLITE_INTERRUPT;
goto abort_parse;
}
break;
}
case TK_ILLEGAL: {
sqlite3DbFree(db, *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);
}
#ifdef YYTRACKMAXSTACKDEPTH
sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
sqlite3ParserStackPeak(pEngine)
);
#endif /* YYDEBUG */
sqlite3ParserFree(pEngine, sqlite3_free);
db->lookaside.bEnabled = enableLookaside;
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
}
if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
sqlite3SetString(&pParse->zErrMsg, db, "%s", sqlite3ErrStr(pParse->rc));
}
assert( pzErrMsg!=0 );
if( pParse->zErrMsg ){
*pzErrMsg = 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 ){
sqlite3DbFree(db, pParse->aTableLock);
pParse->aTableLock = 0;
pParse->nTableLock = 0;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqlite3DbFree(db, pParse->apVtabLock);
#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(db, pParse->pNewTrigger);
sqlite3DbFree(db, pParse->apVarExpr);
sqlite3DbFree(db, pParse->aAlias);
while( pParse->pAinc ){
AutoincInfo *p = pParse->pAinc;
pParse->pAinc = p->pNext;
sqlite3DbFree(db, p);
}
while( pParse->pZombieTab ){
Table *p = pParse->pZombieTab;
pParse->pZombieTab = p->pNextZombie;
sqlite3DeleteTable(p);
}
if( nErr>0 && pParse->rc==SQLITE_OK ){
pParse->rc = SQLITE_ERROR;
}
return nErr;
}
/* This function is used by SQL generated to implement the
** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER
** statement. The second is a table name. The table name in the CREATE
** TRIGGER statement is replaced with the third argument and the result
** returned. This is analagous to renameTableFunc() above, except for CREATE
** TRIGGER, not CREATE INDEX and CREATE TABLE.
这个函数使用SQL执行ALTER TABLE命令生成。
第一个参数是创建触发器语句的文本。
第二个是表名。
创建触发器语句中的表名被替换为第三个参数,返回的结果。
这类似上面的renameTableFunc（）函数
,除了创建触发器,不用创建索引和创建表。
*/
static void renameTriggerFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
unsigned char const *zSql = sqlite3_value_text(argv[0]);
unsigned char const *zTableName = sqlite3_value_text(argv[1]);
int token;
Token tname;
int dist = 3;
unsigned char const *zCsr = zSql;
int len = 0;
char *zRet;
sqlite3 *db = sqlite3_context_db_handle(context);
UNUSED_PARAMETER(NotUsed);
/* The principle used to locate the table name in the CREATE TRIGGER
** statement is that the table name is the first token that is immediatedly
** preceded by either TK_ON or TK_DOT and immediatedly followed by one
** of TK_WHEN, TK_BEGIN or TK_FOR.
原理用于在创建定位触发器语句的表名,表名是第一个令牌,
这个令牌立即为TK_ON或TK_DOT 加上前言，同时也是紧随其后TK_WHEN,TK_BEGIN或TK_FOR之一。
*/
if( zSql ){
do {
if( !*zCsr ){
/* Ran out of input before finding the table name. Return NULL. 找到一个开括号之前放弃输入。返回null。*/
return;
}
/* Store the token that zCsr points to in tname. 存储tname zCsr指向表名的令牌*/
tname.z = (char*)zCsr;
tname.n = len;
/* Advance zCsr to the next token. Store that token type in 'token',
** and its length in 'len' (to be used next iteration of this loop).
推进zCsr到下一个令牌。令牌类型存储用“token”,
和它的长度的用‘len’(下一个迭代的循环使用)。
*/
do {
zCsr += len;
len = sqlite3GetToken(zCsr, &token);
}while( token==TK_SPACE );
assert( len>0 );
/* Variable 'dist' stores the number of tokens read since the most
** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN
** token is read and 'dist' equals 2, the condition stated above
** to be met.
**
** Note that ON cannot be a database, table or column name, so
** there is no need to worry about syntax like
** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc.
变量'dist'存储令牌数量读最近TK_DOT或TK_ON。
这意味着当一个when,for或begin是读时，'dist'为2,满足上述条件。
注释ON不能是一个数据库、表或列名称,
所以没有必要担心语法如"CREATE TRIGGER ... ON ON.ON BEGIN ..." 等。
*/
dist++;
if( token==TK_DOT || token==TK_ON ){
dist = 0;
}
} while( dist!=2 || (token!=TK_WHEN && token!=TK_FOR && token!=TK_BEGIN) );
/* Variable tname now contains the token that is the old table-name
** in the CREATE TRIGGER statement.
现在变量tname包含在创建触发器语句旧表名的令牌。
*/
zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", ((u8*)tname.z) - zSql, zSql,
zTableName, tname.z+tname.n);
sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
}
}
/*
** Run the parser on the given SQL string. The parser structure is passed in.
** An SQLITE_ status code is returned. If an error occurs then an attempt is
** made to write an error message into memory obtained from sqlite3_malloc() and
** to make *pzErrMsg point to that error message.
*/
int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg)
{
int nErr = 0; /* Number of errors encountered */
int positionInStr = 0; /* position in sql statement string */
void *pEngine = 0; /* The LEMON-generated LALR(1) parser */
int tokenType = 0; /* type of the next token */
int lastTokenTypeParsed = -1; /* type of the previous token */
const int mxSqlLen = 1000000; /* Max length of an SQL string */
// The maximum number of bytes in the text of an SQL statement is limited to SQLITE_MAX_SQL_LENGTH which defaults to 1000000.
assert( pzErrMsg!=0 );
pParse->rc = 0; //SQLITE_OK;
// per the description of 'struct Parse', 'zTail' always holds all remaining text after the last known semicolon
pParse->zTail = zSql;
pEngine = sqlite3ParserAlloc(malloc);
if( pEngine==0 )
{
pParse->rc = 8;
return 8;//SQLITE_NOMEM;
}
assert( pParse->pNewTable==0 );
assert( pParse->pNewTrigger==0 );
assert( pParse->nVar==0 );
assert( pParse->nzVar==0 );
assert( pParse->azVar==0 );
while( zSql[positionInStr] != 0 )
{
assert( positionInStr>=0 );
pParse->sLastToken.z = &zSql[positionInStr]; // the entire string 'tail' from current position onward
pParse->sLastToken.n = // the size (character count) of whichever token just got found
sqlite3GetToken( (unsigned char*)&zSql[positionInStr], &tokenType );
positionInStr += pParse->sLastToken.n;
if( positionInStr > mxSqlLen )
{
pParse->rc = 1;// SQLITE_TOOBIG;
break;
}
switch( tokenType )
{
case TK_SPACE:
{
// every time the tokenizer code finds whitespace, we get here. we just ignore it.
break; // break from SWITCH, not the while loop...
}
case TK_ILLEGAL:
{
// this will happen if you use invalid tokens. for example: this is ok --> "!=" but this is not --> "!!"
pParse->rc = -1;
printf(" unrecognized token: %s\n", pParse->sLastToken.z );
nErr++;
goto abort_parse;
}
case TK_SEMI:
{
// found a SEMICOLON (;)
// Per the description of 'struct Parse', 'zTail' always holds all remaining text after the last known semicolon
pParse->zTail = &zSql[positionInStr];
/* Fall thru into the default case */
}
default:
{
// normal "happy path" ... just accept this token and continue parsing
sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
lastTokenTypeParsed = tokenType;
if( pParse->rc != 0 )
{
goto abort_parse;
}
break; // break from SWITCH, not the while loop...
}
}// end switch statement
}// end while loop that consumes the statement string
abort_parse:
if( zSql[positionInStr]==0 // found null terminator
&& nErr==0 // no counted errors
&& pParse->rc==0 // no parser error state
)
{
// we finished with no errors, but without a ';', so just add a ';' now
if( lastTokenTypeParsed != TK_SEMI )
{
sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
pParse->zTail = &zSql[positionInStr];
}
sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
}
// if we somehow counted an error yet pParse shows 'OK' state, then force pParse to show error state
if( nErr>0 && pParse->rc==0 )
{
pParse->rc = 1;//SQLITE_ERROR;
}
sqlite3ParserFree(pEngine, free );
return nErr;
}
