Add parse location to IndexElem.

This patch mostly just fills in the field, although a few error
reports in resolve_unique_index_expr() are adjusted to use it.
The next commit will add more uses.

catversion bump out of an abundance of caution: I'm not sure
IndexElem can appear in stored rules, but I'm not sure it can't
either.

Author: Álvaro Herrera <alvherre@kurilemu.de>
Co-authored-by: jian he <jian.universality@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CACJufxH3OgXF1hrzGAaWyNtye2jHEmk9JbtrtGv-KJK6tsGo5w@mail.gmail.com
Discussion: https://postgr.es/m/202512121327.f2zimsr6guso@alvherre.pgsql

src/backend/bootstrap/bootparse.y

@@ -415,6 +415,7 @@ boot_index_param:
 					n->opclass = list_make1(makeString($2));
 					n->ordering = SORTBY_DEFAULT;
 					n->nulls_ordering = SORTBY_NULLS_DEFAULT;
+					n->location = -1;
 					$$ = n;
 				}
 		;

src/backend/nodes/nodeFuncs.c

@@ -1726,6 +1726,9 @@ exprLocation(const Node *expr)
 		case T_ColumnDef:
 			loc = ((const ColumnDef *) expr)->location;
 			break;
+		case T_IndexElem:
+			loc = ((const IndexElem *) expr)->location;
+			break;
 		case T_Constraint:
 			loc = ((const Constraint *) expr)->location;
 			break;

src/backend/parser/gram.y

@@ -8454,6 +8454,7 @@ index_elem_options:
 			$$->opclassopts = NIL;
 			$$->ordering = $3;
 			$$->nulls_ordering = $4;
+			/* location will be filled in index_elem production */
 		}
 	| opt_collate any_name reloptions opt_asc_desc opt_nulls_order
 		{
@@ -8466,6 +8467,7 @@ index_elem_options:
 			$$->opclassopts = $3;
 			$$->ordering = $4;
 			$$->nulls_ordering = $5;
+			/* location will be filled in index_elem production */
 		}
 	;
 
@@ -8478,16 +8480,19 @@ index_elem: ColId index_elem_options
 				{
 					$$ = $2;
 					$$->name = $1;
+					$$->location = @1;
 				}
 			| func_expr_windowless index_elem_options
 				{
 					$$ = $2;
 					$$->expr = $1;
+					$$->location = @1;
 				}
 			| '(' a_expr ')' index_elem_options
 				{
 					$$ = $4;
 					$$->expr = $2;
+					$$->location = @1;
 				}
 		;
 

src/backend/parser/parse_clause.c

@@ -3288,21 +3288,18 @@ resolve_unique_index_expr(ParseState *pstate, InferClause *infer,
 					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 					 errmsg("%s is not allowed in ON CONFLICT clause",
 							"ASC/DESC"),
-					 parser_errposition(pstate,
-										exprLocation((Node *) infer))));
+					 parser_errposition(pstate, ielem->location)));
 		if (ielem->nulls_ordering != SORTBY_NULLS_DEFAULT)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 					 errmsg("%s is not allowed in ON CONFLICT clause",
 							"NULLS FIRST/LAST"),
-					 parser_errposition(pstate,
-										exprLocation((Node *) infer))));
+					 parser_errposition(pstate, ielem->location)));
 		if (ielem->opclassopts)
 			ereport(ERROR,
 					errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 					errmsg("operator class options are not allowed in ON CONFLICT clause"),
-					parser_errposition(pstate,
-									   exprLocation((Node *) infer)));
+					parser_errposition(pstate, ielem->location));
 
 		if (!ielem->expr)
 		{
@@ -3342,7 +3339,7 @@ resolve_unique_index_expr(ParseState *pstate, InferClause *infer,
 			pInfer->infercollid = InvalidOid;
 		else
 			pInfer->infercollid = LookupCollation(pstate, ielem->collation,
-												  exprLocation(pInfer->expr));
+												  ielem->location);
 
 		if (!ielem->opclass)
 			pInfer->inferopclass = InvalidOid;

src/backend/parser/parse_utilcmd.c

@@ -1962,6 +1962,8 @@ generateClonedIndexStmt(RangeVar *heapRel, Relation source_idx,
 			}
 		}
 
+		iparam->location = -1;
+
 		index->indexParams = lappend(index->indexParams, iparam);
 	}
 
@@ -1993,6 +1995,8 @@ generateClonedIndexStmt(RangeVar *heapRel, Relation source_idx,
 		/* Copy the original index column name */
 		iparam->indexcolname = pstrdup(NameStr(attr->attname));
 
+		iparam->location = -1;
+
 		index->indexIncludingParams = lappend(index->indexIncludingParams, iparam);
 	}
 	/* Copy reloptions if any */
@@ -2813,6 +2817,7 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt)
 			iparam->opclassopts = NIL;
 			iparam->ordering = SORTBY_DEFAULT;
 			iparam->nulls_ordering = SORTBY_NULLS_DEFAULT;
+			iparam->location = -1;
 			index->indexParams = lappend(index->indexParams, iparam);
 		}
 
@@ -2929,6 +2934,7 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt)
 		iparam->collation = NIL;
 		iparam->opclass = NIL;
 		iparam->opclassopts = NIL;
+		iparam->location = -1;
 		index->indexIncludingParams = lappend(index->indexIncludingParams, iparam);
 	}
 

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202601011
+#define CATALOG_VERSION_NO	202601041
 
 #endif

src/include/nodes/parsenodes.h

@@ -816,6 +816,7 @@ typedef struct IndexElem
 	List	   *opclassopts;	/* opclass-specific options, or NIL */
 	SortByDir	ordering;		/* ASC/DESC/default */
 	SortByNulls nulls_ordering; /* FIRST/LAST/default */
+	ParseLoc	location;		/* token location, or -1 if unknown */
 } IndexElem;
 
 /*

src/test/regress/expected/insert_conflict.out

@@ -5,15 +5,15 @@ create table insertconflicttest(key int4, fruit text);
 -- invalid clauses
 insert into insertconflicttest values (1) on conflict (key int4_ops (fillfactor=10)) do nothing;
 ERROR:  operator class options are not allowed in ON CONFLICT clause
-LINE 1: ...rt into insertconflicttest values (1) on conflict (key int4_...
+LINE 1: ...t into insertconflicttest values (1) on conflict (key int4_o...
                                                              ^
 insert into insertconflicttest values (1) on conflict (key asc) do nothing;
 ERROR:  ASC/DESC is not allowed in ON CONFLICT clause
-LINE 1: ...rt into insertconflicttest values (1) on conflict (key asc) ...
+LINE 1: ...t into insertconflicttest values (1) on conflict (key asc) d...
                                                              ^
 insert into insertconflicttest values (1) on conflict (key nulls last) do nothing;
 ERROR:  NULLS FIRST/LAST is not allowed in ON CONFLICT clause
-LINE 1: ...rt into insertconflicttest values (1) on conflict (key nulls...
+LINE 1: ...t into insertconflicttest values (1) on conflict (key nulls ...
                                                              ^
 -- These things should work through a view, as well
 create view insertconflictview as select * from insertconflicttest;