Add location field to DefElem

Add a location field to the DefElem struct, used to parse many utility
commands.  Update various error messages to supply error position
information.

To propogate the error position information in a more systematic way,
create a ParseState in standard_ProcessUtility() and pass that to
interested functions implementing the utility commands.  This seems
better than passing the query string and then reassembling a parse state
ad hoc, which violates the encapsulation of the ParseState type.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>

src/backend/nodes/copyfuncs.c

@@ -2676,6 +2676,7 @@ _copyDefElem(const DefElem *from)
 	COPY_STRING_FIELD(defname);
 	COPY_NODE_FIELD(arg);
 	COPY_SCALAR_FIELD(defaction);
+	COPY_LOCATION_FIELD(location);
 
 	return newnode;
 }

src/backend/nodes/equalfuncs.c

@@ -2424,6 +2424,7 @@ _equalDefElem(const DefElem *a, const DefElem *b)
 	COMPARE_STRING_FIELD(defname);
 	COMPARE_NODE_FIELD(arg);
 	COMPARE_SCALAR_FIELD(defaction);
+	COMPARE_LOCATION_FIELD(location);
 
 	return true;
 }
@@ -2434,6 +2435,7 @@ _equalLockingClause(const LockingClause *a, const LockingClause *b)
 	COMPARE_NODE_FIELD(lockedRels);
 	COMPARE_SCALAR_FIELD(strength);
 	COMPARE_SCALAR_FIELD(waitPolicy);
+	COMPARE_LOCATION_FIELD(location);
 
 	return true;
 }

src/backend/nodes/makefuncs.c

@@ -540,7 +540,7 @@ makeFuncExpr(Oid funcid, Oid rettype, List *args,
  * and no special action.
  */
 DefElem *
-makeDefElem(char *name, Node *arg)
+makeDefElem(char *name, Node *arg, int location)
 {
 	DefElem    *res = makeNode(DefElem);
 
@@ -548,6 +548,7 @@ makeDefElem(char *name, Node *arg)
 	res->defname = name;
 	res->arg = arg;
 	res->defaction = DEFELEM_UNSPEC;
+	res->location = location;
 
 	return res;
 }
@@ -558,7 +559,7 @@ makeDefElem(char *name, Node *arg)
  */
 DefElem *
 makeDefElemExtended(char *nameSpace, char *name, Node *arg,
-					DefElemAction defaction)
+					DefElemAction defaction, int location)
 {
 	DefElem    *res = makeNode(DefElem);
 
@@ -566,6 +567,7 @@ makeDefElemExtended(char *nameSpace, char *name, Node *arg,
 	res->defname = name;
 	res->arg = arg;
 	res->defaction = defaction;
+	res->location = location;
 
 	return res;
 }

src/backend/nodes/outfuncs.c

@@ -2542,6 +2542,7 @@ _outDefElem(StringInfo str, const DefElem *node)
 	WRITE_STRING_FIELD(defname);
 	WRITE_NODE_FIELD(arg);
 	WRITE_ENUM_FIELD(defaction, DefElemAction);
+	WRITE_LOCATION_FIELD(location);
 }
 
 static void

src/backend/nodes/readfuncs.c

@@ -1388,6 +1388,7 @@ _readDefElem(void)
 	READ_STRING_FIELD(defname);
 	READ_NODE_FIELD(arg);
 	READ_ENUM_FIELD(defaction, DefElemAction);
+	READ_LOCATION_FIELD(location);
 
 	READ_DONE();
 }