parse.y

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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.
**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.231 2007/06/20 12:18:31 drh Exp $
*/

// All token codes are small integers with #defines that begin with "TK_"
%token_prefix TK_

// The type of the data attached to each token is Token.  This is also the
// default type for non-terminals.
//
%token_type {Token}
%default_type {Token}

// The generated parser function takes a 4th argument as follows:
%extra_argument {Parse *pParse}

// This code runs whenever there is a syntax error
//
%syntax_error {
  if( !pParse->parseError ){
    if( TOKEN.z[0] ){
      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
    }else{
      sqlite3ErrorMsg(pParse, "incomplete SQL statement");
    }
    pParse->parseError = 1;
  }
}
%stack_overflow {
  sqlite3ErrorMsg(pParse, "parser stack overflow");
  pParse->parseError = 1;
}

// The name of the generated procedure that implements the parser
// is as follows:
%name sqlite3Parser

// The following text is included near the beginning of the C source
// code file that implements the parser.
//
%include {
#include "sqliteInt.h"
#include "parse.h"

/*
** An instance of this structure holds information about the
** LIMIT clause of a SELECT statement.
*/
struct LimitVal {
  Expr *pLimit;    /* The LIMIT expression.  NULL if there is no limit */
  Expr *pOffset;   /* The OFFSET expression.  NULL if there is none */
};

/*
** An instance of this structure is used to store the LIKE,
** GLOB, NOT LIKE, and NOT GLOB operators.
*/
struct LikeOp {
  Token eOperator;  /* "like" or "glob" or "regexp" */
  int not;         /* True if the NOT keyword is present */
};

/*
** An instance of the following structure describes the event of a
** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
** TK_DELETE, or TK_INSTEAD.  If the event is of the form
**
**      UPDATE ON (a,b,c)
**
** Then the "b" IdList records the list "a,b,c".
*/
struct TrigEvent { int a; IdList * b; };

/*
** An instance of this structure holds the ATTACH key and the key type.
*/
struct AttachKey { int type;  Token key; };

} // end %include

// Input is a single SQL command
input ::= cmdlist.
cmdlist ::= cmdlist ecmd.
cmdlist ::= ecmd.
cmdx ::= cmd.           { sqlite3FinishCoding(pParse); }
ecmd ::= SEMI.
ecmd ::= explain cmdx SEMI.
explain ::= .           { sqlite3BeginParse(pParse, 0); }
%ifndef SQLITE_OMIT_EXPLAIN
explain ::= EXPLAIN.              { sqlite3BeginParse(pParse, 1); }
explain ::= EXPLAIN QUERY PLAN.   { sqlite3BeginParse(pParse, 2); }
%endif  SQLITE_OMIT_EXPLAIN

///////////////////// Begin and end transactions. ////////////////////////////
//

cmd ::= BEGIN transtype(Y) trans_opt.  {sqlite3BeginTransaction(pParse, Y);}
trans_opt ::= .
trans_opt ::= TRANSACTION.
trans_opt ::= TRANSACTION nm.
%type transtype {int}
transtype(A) ::= .             {A = TK_DEFERRED;}
transtype(A) ::= DEFERRED(X).  {A = @X;}
transtype(A) ::= IMMEDIATE(X). {A = @X;}
transtype(A) ::= EXCLUSIVE(X). {A = @X;}
cmd ::= COMMIT trans_opt.      {sqlite3CommitTransaction(pParse);}
cmd ::= END trans_opt.         {sqlite3CommitTransaction(pParse);}
cmd ::= ROLLBACK trans_opt.    {sqlite3RollbackTransaction(pParse);}

///////////////////// The CREATE TABLE statement ////////////////////////////
//
cmd ::= create_table create_table_args.
create_table ::= CREATE temp(T) TABLE ifnotexists(E) nm(Y) dbnm(Z). {
   sqlite3StartTable(pParse,&Y,&Z,T,0,0,E);
}
%type ifnotexists {int}
ifnotexists(A) ::= .              {A = 0;}
ifnotexists(A) ::= IF NOT EXISTS. {A = 1;}
%type temp {int}
%ifndef SQLITE_OMIT_TEMPDB
temp(A) ::= TEMP.  {A = 1;}
%endif  SQLITE_OMIT_TEMPDB
temp(A) ::= .      {A = 0;}
create_table_args ::= LP columnlist conslist_opt(X) RP(Y). {
  sqlite3EndTable(pParse,&X,&Y,0);
}
create_table_args ::= AS select(S). {
  sqlite3EndTable(pParse,0,0,S);
  sqlite3SelectDelete(S);
}
columnlist ::= columnlist COMMA column.
columnlist ::= column.

// A "column" is a complete description of a single column in a
// CREATE TABLE statement.  This includes the column name, its
// datatype, and other keywords such as PRIMARY KEY, UNIQUE, REFERENCES,
// NOT NULL and so forth.
//
column(A) ::= columnid(X) type carglist. {
  A.z = X.z;
  A.n = (pParse->sLastToken.z-X.z) + pParse->sLastToken.n;
}
columnid(A) ::= nm(X). {
  sqlite3AddColumn(pParse,&X);
  A = X;
}


// An IDENTIFIER can be a generic identifier, or one of several
// keywords.  Any non-standard keyword can also be an identifier.
//
%type id {Token}
id(A) ::= ID(X).         {A = X;}

// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
  ABORT AFTER ANALYZE ASC ATTACH BEFORE BEGIN CASCADE CAST CONFLICT
  DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH PLAN
  QUERY KEY OF OFFSET PRAGMA RAISE REPLACE RESTRICT ROW
  TEMP TRIGGER VACUUM VIEW VIRTUAL
%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.

// Define operator precedence early so that this is the first occurance
// of the operator tokens in the grammer.  Keeping the operators together
// causes them to be assigned integer values that are close together,
// which keeps parser tables smaller.
//
// The token values assigned to these symbols is determined by the order
// in which lemon first sees them.  It must be the case that ISNULL/NOTNULL,
// NE/EQ, GT/LE, and GE/LT are separated by only a single value.  See
// the sqlite3ExprIfFalse() routine for additional information on this
// constraint.
//
%left OR.
%left AND.
%right NOT.
%left IS MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
%left GT LE LT GE.
%right ESCAPE.
%left BITAND BITOR LSHIFT RSHIFT.
%left PLUS MINUS.
%left STAR SLASH REM.
%left CONCAT.
%left COLLATE.
%right UMINUS UPLUS BITNOT.

// And "ids" is an identifer-or-string.
//
%type ids {Token}
ids(A) ::= ID|STRING(X).   {A = X;}

// The name of a column or table can be any of the following:
//
%type nm {Token}
nm(A) ::= ID(X).         {A = X;}
nm(A) ::= STRING(X).     {A = X;}
nm(A) ::= JOIN_KW(X).    {A = X;}

// A typetoken is really one or more tokens that form a type name such
// as can be found after the column name in a CREATE TABLE statement.
// Multiple tokens are concatenated to form the value of the typetoken.
//
%type typetoken {Token}
type ::= .
type ::= typetoken(X).                   {sqlite3AddColumnType(pParse,&X);}
typetoken(A) ::= typename(X).   {A = X;}
typetoken(A) ::= typename(X) LP signed RP(Y). {
  A.z = X.z;
  A.n = &Y.z[Y.n] - X.z;
}
typetoken(A) ::= typename(X) LP signed COMMA signed RP(Y). {
  A.z = X.z;
  A.n = &Y.z[Y.n] - X.z;
}
%type typename {Token}
typename(A) ::= ids(X).             {A = X;}
typename(A) ::= typename(X) ids(Y). {A.z=X.z; A.n=Y.n+(Y.z-X.z);}
signed ::= plus_num.
signed ::= minus_num.

// "carglist" is a list of additional constraints that come after the
// column name and column type in a CREATE TABLE statement.
//
carglist ::= carglist carg.
carglist ::= .
carg ::= CONSTRAINT nm ccons.
carg ::= ccons.
ccons ::= DEFAULT term(X).            {sqlite3AddDefaultValue(pParse,X);}
ccons ::= DEFAULT LP expr(X) RP.      {sqlite3AddDefaultValue(pParse,X);}
ccons ::= DEFAULT PLUS term(X).       {sqlite3AddDefaultValue(pParse,X);}
ccons ::= DEFAULT MINUS term(X).      {
  Expr *p = sqlite3Expr(TK_UMINUS, X, 0, 0);
  sqlite3AddDefaultValue(pParse,p);
}
ccons ::= DEFAULT id(X).              {
  Expr *p = sqlite3Expr(TK_STRING, 0, 0, &X);
  sqlite3AddDefaultValue(pParse,p);
}

// In addition to the type name, we also care about the primary key and
// UNIQUE constraints.
//
ccons ::= NULL onconf.
ccons ::= NOT NULL onconf(R).               {sqlite3AddNotNull(pParse, R);}
ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
                                     {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
ccons ::= UNIQUE onconf(R).    {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0,0);}
ccons ::= CHECK LP expr(X) RP.       {sqlite3AddCheckConstraint(pParse,X);}
ccons ::= REFERENCES nm(T) idxlist_opt(TA) refargs(R).
                                {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
ccons ::= defer_subclause(D).   {sqlite3DeferForeignKey(pParse,D);}
ccons ::= COLLATE id(C).  {sqlite3AddCollateType(pParse, (char*)C.z, C.n);}

// The optional AUTOINCREMENT keyword
%type autoinc {int}
autoinc(X) ::= .          {X = 0;}
autoinc(X) ::= AUTOINCR.  {X = 1;}

// The next group of rules parses the arguments to a REFERENCES clause
// that determine if the referential integrity checking is deferred or
// or immediate and which determine what action to take if a ref-integ
// check fails.
//
%type refargs {int}
refargs(A) ::= .                     { A = OE_Restrict * 0x010101; }
refargs(A) ::= refargs(X) refarg(Y). { A = (X & Y.mask) | Y.value; }
%type refarg {struct {int value; int mask;}}
refarg(A) ::= MATCH nm.              { A.value = 0;     A.mask = 0x000000; }
refarg(A) ::= ON DELETE refact(X).   { A.value = X;     A.mask = 0x0000ff; }
refarg(A) ::= ON UPDATE refact(X).   { A.value = X<<8;  A.mask = 0x00ff00; }
refarg(A) ::= ON INSERT refact(X).   { A.value = X<<16; A.mask = 0xff0000; }
%type refact {int}
refact(A) ::= SET NULL.              { A = OE_SetNull; }
refact(A) ::= SET DEFAULT.           { A = OE_SetDflt; }
refact(A) ::= CASCADE.               { A = OE_Cascade; }
refact(A) ::= RESTRICT.              { A = OE_Restrict; }
%type defer_subclause {int}
defer_subclause(A) ::= NOT DEFERRABLE init_deferred_pred_opt(X).  {A = X;}
defer_subclause(A) ::= DEFERRABLE init_deferred_pred_opt(X).      {A = X;}
%type init_deferred_pred_opt {int}
init_deferred_pred_opt(A) ::= .                       {A = 0;}
init_deferred_pred_opt(A) ::= INITIALLY DEFERRED.     {A = 1;}
init_deferred_pred_opt(A) ::= INITIALLY IMMEDIATE.    {A = 0;}

// For the time being, the only constraint we care about is the primary
// key and UNIQUE.  Both create indices.
//
conslist_opt(A) ::= .                   {A.n = 0; A.z = 0;}
conslist_opt(A) ::= COMMA(X) conslist.  {A = X;}
conslist ::= conslist COMMA tcons.
conslist ::= conslist tcons.
conslist ::= tcons.
tcons ::= CONSTRAINT nm.
tcons ::= PRIMARY KEY LP idxlist(X) autoinc(I) RP onconf(R).
                                         {sqlite3AddPrimaryKey(pParse,X,R,I,0);}
tcons ::= UNIQUE LP idxlist(X) RP onconf(R).
                                 {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0,0,0);}
tcons ::= CHECK LP expr(E) RP onconf. {sqlite3AddCheckConstraint(pParse,E);}
tcons ::= FOREIGN KEY LP idxlist(FA) RP
          REFERENCES nm(T) idxlist_opt(TA) refargs(R) defer_subclause_opt(D). {
    sqlite3CreateForeignKey(pParse, FA, &T, TA, R);
    sqlite3DeferForeignKey(pParse, D);
}
%type defer_subclause_opt {int}
defer_subclause_opt(A) ::= .                    {A = 0;}
defer_subclause_opt(A) ::= defer_subclause(X).  {A = X;}

// The following is a non-standard extension that allows us to declare the
// default behavior when there is a constraint conflict.
//
%type onconf {int}
%type orconf {int}
%type resolvetype {int}
onconf(A) ::= .                              {A = OE_Default;}
onconf(A) ::= ON CONFLICT resolvetype(X).    {A = X;}
orconf(A) ::= .                              {A = OE_Default;}
orconf(A) ::= OR resolvetype(X).             {A = X;}
resolvetype(A) ::= raisetype(X).             {A = X;}
resolvetype(A) ::= IGNORE.                   {A = OE_Ignore;}
resolvetype(A) ::= REPLACE.                  {A = OE_Replace;}

////////////////////////// The DROP TABLE /////////////////////////////////////
//
cmd ::= DROP TABLE ifexists(E) fullname(X). {
  sqlite3DropTable(pParse, X, 0, E);
}
%type ifexists {int}
ifexists(A) ::= IF EXISTS.   {A = 1;}
ifexists(A) ::= .            {A = 0;}

///////////////////// The CREATE VIEW statement /////////////////////////////
//
%ifndef SQLITE_OMIT_VIEW
cmd ::= CREATE(X) temp(T) VIEW ifnotexists(E) nm(Y) dbnm(Z) AS select(S). {
  sqlite3CreateView(pParse, &X, &Y, &Z, S, T, E);
}
cmd ::= DROP VIEW ifexists(E) fullname(X). {
  sqlite3DropTable(pParse, X, 1, E);
}
%endif  SQLITE_OMIT_VIEW

//////////////////////// The SELECT statement /////////////////////////////////
//
cmd ::= select(X).  {