diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 90dfac2..64bd254 100644 *** a/src/backend/parser/gram.y --- b/src/backend/parser/gram.y *************** static Node *makeRecursiveViewSelect(cha *** 470,476 **** %type def_arg columnElem where_clause where_or_current_clause a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound columnref in_expr having_clause func_table xmltable array_expr ! ExclusionWhereClause operator_def_arg %type rowsfrom_item rowsfrom_list opt_col_def_list %type opt_ordinality %type ExclusionConstraintList ExclusionConstraintElem --- 470,476 ---- %type def_arg columnElem where_clause where_or_current_clause a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound columnref in_expr having_clause func_table xmltable array_expr ! ct_row_expr ExclusionWhereClause operator_def_arg %type rowsfrom_item rowsfrom_list opt_col_def_list %type opt_ordinality %type ExclusionConstraintList ExclusionConstraintElem *************** set_clause: *** 11070,11076 **** $1->val = (Node *) $3; $$ = list_make1($1); } ! | '(' set_target_list ')' '=' a_expr { int ncolumns = list_length($2); int i = 1; --- 11070,11076 ---- $1->val = (Node *) $3; $$ = list_make1($1); } ! | '(' set_target_list ')' '=' ct_row_expr { int ncolumns = list_length($2); int i = 1; *************** c_expr: columnref { $$ = $1; } *** 13451,13457 **** n->indirection = check_indirection($4, yyscanner); $$ = (Node *)n; } ! else if (operator_precedence_warning) { /* * If precedence warnings are enabled, insert --- 13451,13458 ---- n->indirection = check_indirection($4, yyscanner); $$ = (Node *)n; } ! else if (operator_precedence_warning || ! pg_yyget_extra(yyscanner)->in_ctre) { /* * If precedence warnings are enabled, insert *************** c_expr: columnref { $$ = $1; } *** 13469,13474 **** --- 13470,13479 ---- * suppress warnings, it's probably safe enough; and * we'd just as soon not waste cycles on dummy parse * nodes if we don't have to. + * + * We also insert AEXPR_PAREN nodes if we're inside a + * ct_row_expr, so that parse analysis can distinguish + * "(x)" from "x" later. */ $$ = (Node *) makeA_Expr(AEXPR_PAREN, NIL, $2, NULL, exprLocation($2)); *************** opt_asymmetric: ASYMMETRIC *** 14599,14604 **** --- 14604,14623 ---- | /*EMPTY*/ ; + /* + * Deal with the spec's poorly-thought-through "contextually typed row value + * expression" syntax. For that, we need to detect whether the expression has + * outer parentheses. We can't define it as "a_expr | (a_expr)" without + * causing reduce/reduce conflicts, so instead force AEXPR_PAREN nodes to be + * inserted for parens throughout the subexpression, and we'll sort it out + * during parse analysis. + */ + ct_row_expr: + { pg_yyget_extra(yyscanner)->in_ctre++; } + a_expr + { pg_yyget_extra(yyscanner)->in_ctre--; $$ = $2; } + ; + /***************************************************************************** * *************** void *** 16328,16331 **** --- 16347,16351 ---- parser_init(base_yy_extra_type *yyext) { yyext->parsetree = NIL; /* in case grammar forgets to set it */ + yyext->in_ctre = 0; /* not handling ct_row_expr */ } diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 385e54a..0d09d7b 100644 *** a/src/backend/parser/parse_expr.c --- b/src/backend/parser/parse_expr.c *************** transformMultiAssignRef(ParseState *psta *** 1499,1515 **** /* We only need to transform the source if this is the first column */ if (maref->colno == 1) { /* * For now, we only allow EXPR SubLinks and RowExprs as the source of * an UPDATE multiassignment. This is sufficient to cover interesting * cases; at worst, someone would have to write (SELECT * FROM expr) * to expand a composite-returning expression of another form. */ ! if (IsA(maref->source, SubLink) && ! ((SubLink *) maref->source)->subLinkType == EXPR_SUBLINK) { /* Relabel it as a MULTIEXPR_SUBLINK */ ! sublink = (SubLink *) maref->source; sublink->subLinkType = MULTIEXPR_SUBLINK; /* And transform it */ sublink = (SubLink *) transformExprRecurse(pstate, --- 1499,1548 ---- /* We only need to transform the source if this is the first column */ if (maref->colno == 1) { + Node *source = maref->source; + bool have_parens = false; + + /* Drill through any AEXPR_PAREN nodes */ + while (source && IsA(source, A_Expr) && + ((A_Expr *) source)->kind == AEXPR_PAREN) + { + have_parens = true; + source = ((A_Expr *) source)->lexpr; + } + + /* + * If we have a single-column assignment, and the RHS had parens but + * isn't a SubLink or RowExpr, pretend it's a single-column RowExpr. + * This is quite broken, as it will cause odd inconsistencies whenever + * we get around to allowing other syntactic cases for the RHS, but + * some people insisted. + */ + if (have_parens && maref->ncolumns == 1 && + !(IsA(source, SubLink) && + ((SubLink *) source)->subLinkType == EXPR_SUBLINK) && + !IsA(source, RowExpr)) + { + RowExpr *r = makeNode(RowExpr); + + r->args = list_make1(source); + r->row_typeid = InvalidOid; + r->colnames = NIL; + r->row_format = COERCE_IMPLICIT_CAST; /* abuse */ + r->location = -1; + source = (Node *) r; + } + /* * For now, we only allow EXPR SubLinks and RowExprs as the source of * an UPDATE multiassignment. This is sufficient to cover interesting * cases; at worst, someone would have to write (SELECT * FROM expr) * to expand a composite-returning expression of another form. */ ! if (IsA(source, SubLink) && ! ((SubLink *) source)->subLinkType == EXPR_SUBLINK) { /* Relabel it as a MULTIEXPR_SUBLINK */ ! sublink = (SubLink *) source; sublink->subLinkType = MULTIEXPR_SUBLINK; /* And transform it */ sublink = (SubLink *) transformExprRecurse(pstate, *************** transformMultiAssignRef(ParseState *psta *** 1542,1552 **** */ sublink->subLinkId = list_length(pstate->p_multiassign_exprs); } ! else if (IsA(maref->source, RowExpr)) { /* Transform the RowExpr, allowing SetToDefault items */ rexpr = (RowExpr *) transformRowExpr(pstate, ! (RowExpr *) maref->source, true); /* Check it returns required number of columns */ --- 1575,1585 ---- */ sublink->subLinkId = list_length(pstate->p_multiassign_exprs); } ! else if (IsA(source, RowExpr)) { /* Transform the RowExpr, allowing SetToDefault items */ rexpr = (RowExpr *) transformRowExpr(pstate, ! (RowExpr *) source, true); /* Check it returns required number of columns */ *************** transformMultiAssignRef(ParseState *psta *** 1568,1574 **** ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("source for a multiple-column UPDATE item must be a sub-SELECT or ROW() expression"), ! parser_errposition(pstate, exprLocation(maref->source)))); } else { --- 1601,1607 ---- ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("source for a multiple-column UPDATE item must be a sub-SELECT or ROW() expression"), ! parser_errposition(pstate, exprLocation(source)))); } else { diff --git a/src/include/parser/gramparse.h b/src/include/parser/gramparse.h index 42e7ede..6e51081 100644 *** a/src/include/parser/gramparse.h --- b/src/include/parser/gramparse.h *************** typedef struct base_yy_extra_type *** 53,58 **** --- 53,59 ---- * State variables that belong to the grammar. */ List *parsetree; /* final parse result is delivered here */ + int in_ctre; /* handling contextually-typed row expr? */ } base_yy_extra_type; /*