diff options
Diffstat (limited to 'src/backend/parser/gram.y')
| -rw-r--r-- | src/backend/parser/gram.y | 102 |
1 files changed, 52 insertions, 50 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 006e545c3a..a88b66c970 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.107 1999/10/05 18:14:31 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.108 1999/10/07 04:23:12 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -72,7 +72,6 @@ static char *xlateSqlType(char *); static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr); static Node *makeRowExpr(char *opr, List *largs, List *rargs); static void mapTargetColumns(List *source, List *target); -static char *fmtId(char *rawid); static void param_type_init(Oid *typev, int nargs); static Node *doNegate(Node *n); @@ -130,7 +129,7 @@ Oid param_type(int t); /* used in parse_expr.c */ UpdateStmt, InsertStmt, select_clause, SelectStmt, NotifyStmt, DeleteStmt, ClusterStmt, ExplainStmt, VariableSetStmt, VariableShowStmt, VariableResetStmt, CreateUserStmt, AlterUserStmt, DropUserStmt, RuleActionStmt, - ConstraintsSetStmt, + RuleActionStmtOrEmpty, ConstraintsSetStmt, %type <str> opt_database1, opt_database2, location, encoding @@ -165,7 +164,7 @@ Oid param_type(int t); /* used in parse_expr.c */ result, relation_name_list, OptTableElementList, OptInherit, definition, opt_with, func_args, func_args_list, func_as, - oper_argtypes, RuleActionList, RuleActionBlock, RuleActionMulti, + oper_argtypes, RuleActionList, RuleActionMulti, opt_column_list, columnList, opt_va_list, va_list, sort_clause, sortby_list, index_params, index_list, name_list, from_clause, from_expr, table_list, opt_array_bounds, @@ -374,17 +373,18 @@ stmtblock: stmtmulti { parsetree = $1; } ; +/* the thrashing around here is to discard "empty" statements... */ stmtmulti: stmtmulti ';' stmt - { if ($3 != (Node *)NIL) + { if ($3 != (Node *)NULL) $$ = lappend($1, $3); else $$ = $1; } | stmt - { if ($1 != (Node *)NIL) + { if ($1 != (Node *)NULL) $$ = lcons($1,NIL); else - $$ = (Node *)NIL; + $$ = NIL; } ; @@ -433,7 +433,7 @@ stmt : AddAttrStmt | VariableResetStmt | ConstraintsSetStmt | /*EMPTY*/ - { $$ = (Node *)NIL; } + { $$ = (Node *)NULL; } ; /***************************************************************************** @@ -930,7 +930,7 @@ ColConstraint: CONSTRAINT name ColConstraintElem { Constraint *n = (Constraint *)$3; - if (n != NULL) n->name = fmtId($2); + if (n != NULL) n->name = $2; $$ = $3; } | ColConstraintElem @@ -1024,7 +1024,7 @@ ColConstraintElem: CHECK '(' a_expr ')' TableConstraint: CONSTRAINT name ConstraintElem { Constraint *n = (Constraint *)$3; - if (n != NULL) n->name = fmtId($2); + if (n != NULL) n->name = $2; $$ = $3; } | ConstraintElem @@ -2034,20 +2034,23 @@ RuleStmt: CREATE RULE name AS RuleActionList: NOTHING { $$ = NIL; } | SelectStmt { $$ = lcons($1, NIL); } | RuleActionStmt { $$ = lcons($1, NIL); } - | '[' RuleActionBlock ']' { $$ = $2; } - | '(' RuleActionBlock ')' { $$ = $2; } - ; - -RuleActionBlock: RuleActionMulti { $$ = $1; } - | RuleActionStmt { $$ = lcons($1, NIL); } + | '[' RuleActionMulti ']' { $$ = $2; } + | '(' RuleActionMulti ')' { $$ = $2; } ; -RuleActionMulti: RuleActionMulti RuleActionStmt - { $$ = lappend($1, $2); } - | RuleActionMulti RuleActionStmt ';' - { $$ = lappend($1, $2); } - | RuleActionStmt ';' - { $$ = lcons($1, NIL); } +/* the thrashing around here is to discard "empty" statements... */ +RuleActionMulti: RuleActionMulti ';' RuleActionStmtOrEmpty + { if ($3 != (Node *)NULL) + $$ = lappend($1, $3); + else + $$ = $1; + } + | RuleActionStmtOrEmpty + { if ($1 != (Node *)NULL) + $$ = lcons($1,NIL); + else + $$ = NIL; + } ; RuleActionStmt: InsertStmt @@ -2056,6 +2059,11 @@ RuleActionStmt: InsertStmt | NotifyStmt ; +RuleActionStmtOrEmpty: RuleActionStmt + | /*EMPTY*/ + { $$ = (Node *)NULL; } + ; + event_object: relation_name '.' attr_name { $$ = makeNode(Attr); @@ -3676,12 +3684,25 @@ a_expr: attr { $$ = makeA_Expr(OP, $2, $1, NULL); } | func_name '(' '*' ')' { - /* cheap hack for aggregate (eg. count) */ + /* + * For now, we transform AGGREGATE(*) into AGGREGATE(1). + * + * This does the right thing for COUNT(*) (in fact, + * any certainly-non-null expression would do for COUNT), + * and there are no other aggregates in SQL92 that accept + * '*' as parameter. + * + * XXX really, the '*' ought to be transformed to some + * special construct that wouldn't be acceptable as the + * input of a non-aggregate function, in case the given + * func_name matches a plain function. This would also + * support a possible extension to let user-defined + * aggregates do something special with '*' as input. + */ FuncCall *n = makeNode(FuncCall); A_Const *star = makeNode(A_Const); - - star->val.type = T_String; - star->val.val.str = ""; + star->val.type = T_Integer; + star->val.val.ival = 1; n->funcname = $1; n->args = lcons(star, NIL); $$ = (Node *)n; @@ -5265,30 +5286,6 @@ void parser_init(Oid *typev, int nargs) } -/* fmtId() - * Check input string for non-lowercase/non-numeric characters. - * Returns either input string or input surrounded by double quotes. - */ -static char * -fmtId(char *rawid) -{ - static char *cp; - - for (cp = rawid; *cp != '\0'; cp++) - if (! (islower(*cp) || isdigit(*cp) || (*cp == '_'))) break; - - if (*cp != '\0') { - cp = palloc(strlen(rawid)+3); - strcpy(cp,"\""); - strcat(cp,rawid); - strcat(cp,"\""); - } else { - cp = rawid; - }; - - return cp; -} - /* * param_type_init() * @@ -5313,6 +5310,11 @@ Oid param_type(int t) * The optimizer doesn't like '-' 4 for index use. It only checks for * Var '=' Const. It wants an integer of -4, so we try to merge the * minus into the constant. + * + * This code is no longer essential as of 10/1999, since the optimizer + * now has a constant-subexpression simplifier. However, we can save + * a few cycles throughout the parse and rewrite stages if we collapse + * the minus into the constant sooner rather than later... */ static Node *doNegate(Node *n) { |