Function parseNodeString

src/backend/nodes/readfuncs.c:2939–3460

* parseNodeString * * Given a character string representing a node tree, parseNodeString creates * the internal node structure. * * The string to be read must already have been loaded into pg_strtok(). */

 * The string to be read must already have been loaded into pg_strtok().
 */
Node *
parseNodeString(void)
{
	void	   *return_value;

	READ_TEMP_LOCALS();

	/* Guard against stack overflow due to overly complex expressions */
	check_stack_depth();

	token = pg_strtok(&length);

#define MATCH(tokname, namelen) \
	(length == namelen && memcmp(token, tokname, namelen) == 0)

	/*
	 * Same as MATCH, but we make our life a bit easier by relying on the
	 * compiler to be smart, and evaluate the strlen("<constant>") at
	 * compilation time for us.
	 */
#define MATCHX(tokname) \
	(length == strlen(tokname) && strncmp(token, tokname, strlen(tokname)) == 0)

	if (MATCH("QUERY", 5))
		return_value = _readQuery();
	else if (MATCH("WITHCHECKOPTION", 15))
		return_value = _readWithCheckOption();
	else if (MATCH("SORTGROUPCLAUSE", 15))
		return_value = _readSortGroupClause();
	else if (MATCH("GROUPINGSET", 11))
		return_value = _readGroupingSet();
	else if (MATCH("WINDOWCLAUSE", 12))
		return_value = _readWindowClause();
	else if (MATCH("ROWMARKCLAUSE", 13))
		return_value = _readRowMarkClause();
	else if (MATCH("CTESEARCHCLAUSE", 15))
		return_value = _readCTESearchClause();
	else if (MATCH("CTECYCLECLAUSE", 14))
		return_value = _readCTECycleClause();
	else if (MATCH("COMMONTABLEEXPR", 15))
		return_value = _readCommonTableExpr();
	else if (MATCH("SETOPERATIONSTMT", 16))
		return_value = _readSetOperationStmt();
	else if (MATCH("ALIAS", 5))
		return_value = _readAlias();
	else if (MATCH("RANGEVAR", 8))
		return_value = _readRangeVar();
	else if (MATCH("INTOCLAUSE", 10))
		return_value = _readIntoClause();
	else if (MATCH("COPYINTOCLAUSE", 14))
		return_value = _readCopyIntoClause();
	else if (MATCH("REFRESHCLAUSE", 13))
		return_value = _readRefreshClause();
	else if (MATCH("TABLEFUNC", 9))
		return_value = _readTableFunc();
	else if (MATCH("VAR", 3))
		return_value = _readVar();
	else if (MATCH("CONST", 5))