diff options
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 274 |
1 files changed, 230 insertions, 44 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 385f8e767e4..e9267c56fc5 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -37,6 +37,7 @@ bool Transform_null_equals = false; +static Node *transformExprRecurse(ParseState *pstate, Node *expr); static Node *transformParamRef(ParseState *pstate, ParamRef *pref); static Node *transformAExprOp(ParseState *pstate, A_Expr *a); static Node *transformAExprAnd(ParseState *pstate, A_Expr *a); @@ -100,9 +101,27 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname, * input and output of transformExpr; see SubLink for example. */ Node * -transformExpr(ParseState *pstate, Node *expr) +transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind) { - Node *result = NULL; + Node *result; + ParseExprKind sv_expr_kind; + + /* Save and restore identity of expression type we're parsing */ + Assert(exprKind != EXPR_KIND_NONE); + sv_expr_kind = pstate->p_expr_kind; + pstate->p_expr_kind = exprKind; + + result = transformExprRecurse(pstate, expr); + + pstate->p_expr_kind = sv_expr_kind; + + return result; +} + +static Node * +transformExprRecurse(ParseState *pstate, Node *expr) +{ + Node *result; if (expr == NULL) return NULL; @@ -133,7 +152,7 @@ transformExpr(ParseState *pstate, Node *expr) { A_Indirection *ind = (A_Indirection *) expr; - result = transformExpr(pstate, ind->arg); + result = transformExprRecurse(pstate, ind->arg); result = transformIndirection(pstate, result, ind->indirection); break; @@ -230,6 +249,8 @@ transformExpr(ParseState *pstate, Node *expr) break; default: elog(ERROR, "unrecognized A_Expr kind: %d", a->kind); + result = NULL; /* keep compiler quiet */ + break; } break; } @@ -242,7 +263,7 @@ transformExpr(ParseState *pstate, Node *expr) { NamedArgExpr *na = (NamedArgExpr *) expr; - na->arg = (Expr *) transformExpr(pstate, (Node *) na->arg); + na->arg = (Expr *) transformExprRecurse(pstate, (Node *) na->arg); result = expr; break; } @@ -279,7 +300,7 @@ transformExpr(ParseState *pstate, Node *expr) { NullTest *n = (NullTest *) expr; - n->arg = (Expr *) transformExpr(pstate, (Node *) n->arg); + n->arg = (Expr *) transformExprRecurse(pstate, (Node *) n->arg); /* the argument can be any type, so don't coerce it */ n->argisrow = type_is_rowtype(exprType((Node *) n->arg)); result = expr; @@ -334,6 +355,7 @@ transformExpr(ParseState *pstate, Node *expr) default: /* should not reach here */ elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr)); + result = NULL; /* keep compiler quiet */ break; } @@ -843,7 +865,7 @@ transformAExprOp(ParseState *pstate, A_Expr *a) else n->arg = (Expr *) lexpr; - result = transformExpr(pstate, (Node *) n); + result = transformExprRecurse(pstate, (Node *) n); } else if (lexpr && IsA(lexpr, RowExpr) && rexpr && IsA(rexpr, SubLink) && @@ -860,14 +882,14 @@ transformAExprOp(ParseState *pstate, A_Expr *a) s->testexpr = lexpr; s->operName = a->name; s->location = a->location; - result = transformExpr(pstate, (Node *) s); + result = transformExprRecurse(pstate, (Node *) s); } else if (lexpr && IsA(lexpr, RowExpr) && rexpr && IsA(rexpr, RowExpr)) { /* "row op row" */ - lexpr = transformExpr(pstate, lexpr); - rexpr = transformExpr(pstate, rexpr); + lexpr = transformExprRecurse(pstate, lexpr); + rexpr = transformExprRecurse(pstate, rexpr); Assert(IsA(lexpr, RowExpr)); Assert(IsA(rexpr, RowExpr)); @@ -880,8 +902,8 @@ transformAExprOp(ParseState *pstate, A_Expr *a) else { /* Ordinary scalar operator */ - lexpr = transformExpr(pstate, lexpr); - rexpr = transformExpr(pstate, rexpr); + lexpr = transformExprRecurse(pstate, lexpr); + rexpr = transformExprRecurse(pstate, rexpr); result = (Node *) make_op(pstate, a->name, @@ -896,8 +918,8 @@ transformAExprOp(ParseState *pstate, A_Expr *a) static Node * transformAExprAnd(ParseState *pstate, A_Expr *a) { - Node *lexpr = transformExpr(pstate, a->lexpr); - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); lexpr = coerce_to_boolean(pstate, lexpr, "AND"); rexpr = coerce_to_boolean(pstate, rexpr, "AND"); @@ -910,8 +932,8 @@ transformAExprAnd(ParseState *pstate, A_Expr *a) static Node * transformAExprOr(ParseState *pstate, A_Expr *a) { - Node *lexpr = transformExpr(pstate, a->lexpr); - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); lexpr = coerce_to_boolean(pstate, lexpr, "OR"); rexpr = coerce_to_boolean(pstate, rexpr, "OR"); @@ -924,7 +946,7 @@ transformAExprOr(ParseState *pstate, A_Expr *a) static Node * transformAExprNot(ParseState *pstate, A_Expr *a) { - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); rexpr = coerce_to_boolean(pstate, rexpr, "NOT"); @@ -936,8 +958,8 @@ transformAExprNot(ParseState *pstate, A_Expr *a) static Node * transformAExprOpAny(ParseState *pstate, A_Expr *a) { - Node *lexpr = transformExpr(pstate, a->lexpr); - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); return (Node *) make_scalar_array_op(pstate, a->name, @@ -950,8 +972,8 @@ transformAExprOpAny(ParseState *pstate, A_Expr *a) static Node * transformAExprOpAll(ParseState *pstate, A_Expr *a) { - Node *lexpr = transformExpr(pstate, a->lexpr); - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); return (Node *) make_scalar_array_op(pstate, a->name, @@ -964,8 +986,8 @@ transformAExprOpAll(ParseState *pstate, A_Expr *a) static Node * transformAExprDistinct(ParseState *pstate, A_Expr *a) { - Node *lexpr = transformExpr(pstate, a->lexpr); - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); if (lexpr && IsA(lexpr, RowExpr) && rexpr && IsA(rexpr, RowExpr)) @@ -990,8 +1012,8 @@ transformAExprDistinct(ParseState *pstate, A_Expr *a) static Node * transformAExprNullIf(ParseState *pstate, A_Expr *a) { - Node *lexpr = transformExpr(pstate, a->lexpr); - Node *rexpr = transformExpr(pstate, a->rexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); + Node *rexpr = transformExprRecurse(pstate, a->rexpr); OpExpr *result; result = (OpExpr *) make_op(pstate, @@ -1029,7 +1051,7 @@ transformAExprOf(ParseState *pstate, A_Expr *a) * Checking an expression for match to a list of type names. Will result * in a boolean constant node. */ - Node *lexpr = transformExpr(pstate, a->lexpr); + Node *lexpr = transformExprRecurse(pstate, a->lexpr); Const *result; ListCell *telem; Oid ltype, @@ -1092,12 +1114,12 @@ transformAExprIn(ParseState *pstate, A_Expr *a) * First step: transform all the inputs, and detect whether any are * RowExprs or contain Vars. */ - lexpr = transformExpr(pstate, a->lexpr); + lexpr = transformExprRecurse(pstate, a->lexpr); haveRowExpr = (lexpr && IsA(lexpr, RowExpr)); rexprs = rvars = rnonvars = NIL; foreach(l, (List *) a->rexpr) { - Node *rexpr = transformExpr(pstate, lfirst(l)); + Node *rexpr = transformExprRecurse(pstate, lfirst(l)); haveRowExpr |= (rexpr && IsA(rexpr, RowExpr)); rexprs = lappend(rexprs, rexpr); @@ -1222,8 +1244,8 @@ transformFuncCall(ParseState *pstate, FuncCall *fn) targs = NIL; foreach(args, fn->args) { - targs = lappend(targs, transformExpr(pstate, - (Node *) lfirst(args))); + targs = lappend(targs, transformExprRecurse(pstate, + (Node *) lfirst(args))); } /* ... and hand off to ParseFuncOrColumn */ @@ -1258,7 +1280,7 @@ transformCaseExpr(ParseState *pstate, CaseExpr *c) newc = makeNode(CaseExpr); /* transform the test expression, if any */ - arg = transformExpr(pstate, (Node *) c->arg); + arg = transformExprRecurse(pstate, (Node *) c->arg); /* generate placeholder for test expression */ if (arg) @@ -1311,14 +1333,14 @@ transformCaseExpr(ParseState *pstate, CaseExpr *c) warg, w->location); } - neww->expr = (Expr *) transformExpr(pstate, warg); + neww->expr = (Expr *) transformExprRecurse(pstate, warg); neww->expr = (Expr *) coerce_to_boolean(pstate, (Node *) neww->expr, "CASE/WHEN"); warg = (Node *) w->result; - neww->result = (Expr *) transformExpr(pstate, warg); + neww->result = (Expr *) transformExprRecurse(pstate, warg); neww->location = w->location; newargs = lappend(newargs, neww); @@ -1337,7 +1359,7 @@ transformCaseExpr(ParseState *pstate, CaseExpr *c) n->location = -1; defresult = (Node *) n; } - newc->defresult = (Expr *) transformExpr(pstate, defresult); + newc->defresult = (Expr *) transformExprRecurse(pstate, defresult); /* * Note: default result is considered the most significant type in @@ -1380,12 +1402,92 @@ transformSubLink(ParseState *pstate, SubLink *sublink) { Node *result = (Node *) sublink; Query *qtree; + const char *err; /* If we already transformed this node, do nothing */ if (IsA(sublink->subselect, Query)) return result; + /* + * Check to see if the sublink is in an invalid place within the query. + * We allow sublinks everywhere in SELECT/INSERT/UPDATE/DELETE, but + * generally not in utility statements. + */ + err = NULL; + switch (pstate->p_expr_kind) + { + case EXPR_KIND_NONE: + Assert(false); /* can't happen */ + break; + case EXPR_KIND_OTHER: + /* Accept sublink here; caller must throw error if wanted */ + break; + case EXPR_KIND_JOIN_ON: + case EXPR_KIND_JOIN_USING: + case EXPR_KIND_FROM_SUBSELECT: + case EXPR_KIND_FROM_FUNCTION: + case EXPR_KIND_WHERE: + case EXPR_KIND_HAVING: + case EXPR_KIND_WINDOW_PARTITION: + case EXPR_KIND_WINDOW_ORDER: + case EXPR_KIND_WINDOW_FRAME_RANGE: + case EXPR_KIND_WINDOW_FRAME_ROWS: + case EXPR_KIND_SELECT_TARGET: + case EXPR_KIND_INSERT_TARGET: + case EXPR_KIND_UPDATE_SOURCE: + case EXPR_KIND_UPDATE_TARGET: + case EXPR_KIND_GROUP_BY: + case EXPR_KIND_ORDER_BY: + case EXPR_KIND_DISTINCT_ON: + case EXPR_KIND_LIMIT: + case EXPR_KIND_OFFSET: + case EXPR_KIND_RETURNING: + case EXPR_KIND_VALUES: + /* okay */ + break; + case EXPR_KIND_CHECK_CONSTRAINT: + case EXPR_KIND_DOMAIN_CHECK: + err = _("cannot use subquery in CHECK constraint"); + break; + case EXPR_KIND_COLUMN_DEFAULT: + case EXPR_KIND_FUNCTION_DEFAULT: + err = _("cannot use subquery in DEFAULT expression"); + break; + case EXPR_KIND_INDEX_EXPRESSION: + err = _("cannot use subquery in index expression"); + break; + case EXPR_KIND_INDEX_PREDICATE: + err = _("cannot use subquery in index predicate"); + break; + case EXPR_KIND_ALTER_COL_TRANSFORM: + err = _("cannot use subquery in transform expression"); + break; + case EXPR_KIND_EXECUTE_PARAMETER: + err = _("cannot use subquery in EXECUTE parameter"); + break; + case EXPR_KIND_TRIGGER_WHEN: + err = _("cannot use subquery in trigger WHEN condition"); + break; + + /* + * There is intentionally no default: case here, so that the + * compiler will warn if we add a new ParseExprKind without + * extending this switch. If we do see an unrecognized value at + * runtime, the behavior will be the same as for EXPR_KIND_OTHER, + * which is sane anyway. + */ + } + if (err) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg_internal("%s", err), + parser_errposition(pstate, sublink->location))); + pstate->p_hasSubLinks = true; + + /* + * OK, let's transform the sub-SELECT. + */ qtree = parse_sub_analyze(sublink->subselect, pstate, NULL, false); /* @@ -1450,7 +1552,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink) /* * Transform lefthand expression, and convert to a list */ - lefthand = transformExpr(pstate, sublink->testexpr); + lefthand = transformExprRecurse(pstate, sublink->testexpr); if (lefthand && IsA(lefthand, RowExpr)) left_list = ((RowExpr *) lefthand)->args; else @@ -1557,7 +1659,7 @@ transformArrayExpr(ParseState *pstate, A_ArrayExpr *a, } else { - newe = transformExpr(pstate, e); + newe = transformExprRecurse(pstate, e); /* * Check for sub-array expressions, if we haven't already found @@ -1679,7 +1781,7 @@ transformRowExpr(ParseState *pstate, RowExpr *r) ListCell *lc; /* Transform the field expressions */ - newr->args = transformExpressionList(pstate, r->args); + newr->args = transformExpressionList(pstate, r->args, pstate->p_expr_kind); /* Barring later casting, we consider the type RECORD */ newr->row_typeid = RECORDOID; @@ -1712,7 +1814,7 @@ transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c) Node *e = (Node *) lfirst(args); Node *newe; - newe = transformExpr(pstate, e); + newe = transformExprRecurse(pstate, e); newargs = lappend(newargs, newe); } @@ -1751,7 +1853,7 @@ transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m) Node *e = (Node *) lfirst(args); Node *newe; - newe = transformExpr(pstate, e); + newe = transformExprRecurse(pstate, e); newargs = lappend(newargs, newe); } @@ -1805,7 +1907,7 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x) Assert(IsA(r, ResTarget)); - expr = transformExpr(pstate, r->val); + expr = transformExprRecurse(pstate, r->val); if (r->name) argname = map_sql_identifier_to_xml_name(r->name, false, false); @@ -1851,7 +1953,7 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x) Node *e = (Node *) lfirst(lc); Node *newe; - newe = transformExpr(pstate, e); + newe = transformExprRecurse(pstate, e); switch (x->op) { case IS_XMLCONCAT: @@ -1914,7 +2016,7 @@ transformXmlSerialize(ParseState *pstate, XmlSerialize *xs) xexpr = makeNode(XmlExpr); xexpr->op = IS_XMLSERIALIZE; xexpr->args = list_make1(coerce_to_specific_type(pstate, - transformExpr(pstate, xs->expr), + transformExprRecurse(pstate, xs->expr), XMLOID, "XMLSERIALIZE")); @@ -1977,7 +2079,7 @@ transformBooleanTest(ParseState *pstate, BooleanTest *b) clausename = NULL; /* keep compiler quiet */ } - b->arg = (Expr *) transformExpr(pstate, (Node *) b->arg); + b->arg = (Expr *) transformExprRecurse(pstate, (Node *) b->arg); b->arg = (Expr *) coerce_to_boolean(pstate, (Node *) b->arg, @@ -2082,7 +2184,7 @@ static Node * transformTypeCast(ParseState *pstate, TypeCast *tc) { Node *result; - Node *expr = transformExpr(pstate, tc->arg); + Node *expr = transformExprRecurse(pstate, tc->arg); Oid inputType = exprType(expr); Oid targetType; int32 targetTypmod; @@ -2130,7 +2232,7 @@ transformCollateClause(ParseState *pstate, CollateClause *c) Oid argtype; newc = makeNode(CollateExpr); - newc->arg = (Expr *) transformExpr(pstate, c->arg); + newc->arg = (Expr *) transformExprRecurse(pstate, c->arg); argtype = exprType((Node *) newc->arg); @@ -2433,3 +2535,87 @@ make_distinct_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree, return result; } + +/* + * Produce a string identifying an expression by kind. + * + * Note: when practical, use a simple SQL keyword for the result. If that + * doesn't work well, check call sites to see whether custom error message + * strings are required. + */ +const char * +ParseExprKindName(ParseExprKind exprKind) +{ + switch (exprKind) + { + case EXPR_KIND_NONE: + return "invalid expression context"; + case EXPR_KIND_OTHER: + return "extension expression"; + case EXPR_KIND_JOIN_ON: + return "JOIN/ON"; + case EXPR_KIND_JOIN_USING: + return "JOIN/USING"; + case EXPR_KIND_FROM_SUBSELECT: + return "sub-SELECT in FROM"; + case EXPR_KIND_FROM_FUNCTION: + return "function in FROM"; + case EXPR_KIND_WHERE: + return "WHERE"; + case EXPR_KIND_HAVING: + return "HAVING"; + case EXPR_KIND_WINDOW_PARTITION: + return "window PARTITION BY"; + case EXPR_KIND_WINDOW_ORDER: + return "window ORDER BY"; + case EXPR_KIND_WINDOW_FRAME_RANGE: + return "window RANGE"; + case EXPR_KIND_WINDOW_FRAME_ROWS: + return "window ROWS"; + case EXPR_KIND_SELECT_TARGET: + return "SELECT"; + case EXPR_KIND_INSERT_TARGET: + return "INSERT"; + case EXPR_KIND_UPDATE_SOURCE: + case EXPR_KIND_UPDATE_TARGET: + return "UPDATE"; + case EXPR_KIND_GROUP_BY: + return "GROUP BY"; + case EXPR_KIND_ORDER_BY: + return "ORDER BY"; + case EXPR_KIND_DISTINCT_ON: + return "DISTINCT ON"; + case EXPR_KIND_LIMIT: + return "LIMIT"; + case EXPR_KIND_OFFSET: + return "OFFSET"; + case EXPR_KIND_RETURNING: + return "RETURNING"; + case EXPR_KIND_VALUES: + return "VALUES"; + case EXPR_KIND_CHECK_CONSTRAINT: + case EXPR_KIND_DOMAIN_CHECK: + return "CHECK"; + case EXPR_KIND_COLUMN_DEFAULT: + case EXPR_KIND_FUNCTION_DEFAULT: + return "DEFAULT"; + case EXPR_KIND_INDEX_EXPRESSION: + return "index expression"; + case EXPR_KIND_INDEX_PREDICATE: + return "index predicate"; + case EXPR_KIND_ALTER_COL_TRANSFORM: + return "USING"; + case EXPR_KIND_EXECUTE_PARAMETER: + return "EXECUTE"; + case EXPR_KIND_TRIGGER_WHEN: + return "WHEN"; + + /* + * There is intentionally no default: case here, so that the + * compiler will warn if we add a new ParseExprKind without + * extending this switch. If we do see an unrecognized value at + * runtime, we'll fall through to the "unrecognized" return. + */ + } + return "unrecognized expression kind"; +} |