pl_comp.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

		case PLPGSQL_NSTYPE_REC:
			{
				/*
				 * This word is a record name, so third word must be a field
				 * in this record.
				 */
				PLpgSQL_recfield *new;

				new = palloc(sizeof(PLpgSQL_recfield));
				new->dtype = PLPGSQL_DTYPE_RECFIELD;
				new->fieldname = pstrdup(cp[2]);
				new->recparentno = ns->itemno;

				plpgsql_adddatum((PLpgSQL_datum *) new);

				plpgsql_yylval.scalar = (PLpgSQL_datum *) new;

				pfree(cp[0]);
				pfree(cp[1]);
				pfree(cp[2]);

				return T_SCALAR;
			}

		case PLPGSQL_NSTYPE_ROW:
			{
				/*
				 * This word is a row name, so third word must be a field in
				 * this row.
				 */
				PLpgSQL_row *row;
				int			i;

				row = (PLpgSQL_row *) (plpgsql_Datums[ns->itemno]);
				for (i = 0; i < row->nfields; i++)
				{
					if (row->fieldnames[i] &&
						strcmp(row->fieldnames[i], cp[2]) == 0)
					{
						plpgsql_yylval.scalar = plpgsql_Datums[row->varnos[i]];

						pfree(cp[0]);
						pfree(cp[1]);
						pfree(cp[2]);

						return T_SCALAR;
					}
				}
				ereport(ERROR,
						(errcode(ERRCODE_UNDEFINED_COLUMN),
						 errmsg("row \"%s.%s\" has no field \"%s\"",
								cp[0], cp[1], cp[2])));
			}

		default:
			break;
	}

	pfree(cp[0]);
	pfree(cp[1]);
	pfree(cp[2]);
	return T_ERROR;
}


/* ----------
 * plpgsql_parse_wordtype	The scanner found word%TYPE. word can be
 *				a variable name or a basetype.
 * ----------
 */
int
plpgsql_parse_wordtype(char *word)
{
	PLpgSQL_nsitem *nse;
	bool		old_nsstate;
	Oid			typeOid;
	char	   *cp[2];
	int			i;

	/* Do case conversion and word separation */
	/* We convert %type to .type momentarily to keep converter happy */
	i = strlen(word) - 5;
	Assert(word[i] == '%');
	word[i] = '.';
	plpgsql_convert_ident(word, cp, 2);
	word[i] = '%';
	pfree(cp[1]);

	/*
	 * Do a lookup on the compiler's namestack. But ensure it moves up to the
	 * toplevel.
	 */
	old_nsstate = plpgsql_ns_setlocal(false);
	nse = plpgsql_ns_lookup(cp[0], NULL);
	plpgsql_ns_setlocal(old_nsstate);

	if (nse != NULL)
	{
		pfree(cp[0]);
		switch (nse->itemtype)
		{
			case PLPGSQL_NSTYPE_VAR:
				plpgsql_yylval.dtype = ((PLpgSQL_var *) (plpgsql_Datums[nse->itemno]))->datatype;
				return T_DTYPE;

				/* XXX perhaps allow REC here? */

			default:
				return T_ERROR;
		}
	}

	/*
	 * Word wasn't found on the namestack. Try to find a data type with that
	 * name, but ignore pg_type entries that are in fact class types.
	 */
	typeOid = LookupTypeName(makeTypeName(cp[0]));
	if (OidIsValid(typeOid))
	{
		HeapTuple	typeTup;

		typeTup = SearchSysCache(TYPEOID,
								 ObjectIdGetDatum(typeOid),
								 0, 0, 0);
		if (HeapTupleIsValid(typeTup))
		{
			Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

			if (!typeStruct->typisdefined ||
				typeStruct->typrelid != InvalidOid)
			{
				ReleaseSysCache(typeTup);
				pfree(cp[0]);
				return T_ERROR;
			}

			plpgsql_yylval.dtype = build_datatype(typeTup, -1);

			ReleaseSysCache(typeTup);
			pfree(cp[0]);
			return T_DTYPE;
		}
	}

	/*
	 * Nothing found - up to now it's a word without any special meaning for
	 * us.
	 */
	pfree(cp[0]);
	return T_ERROR;
}


/* ----------
 * plpgsql_parse_dblwordtype		Same lookup for word.word%TYPE
 * ----------
 */
int
plpgsql_parse_dblwordtype(char *word)
{
	PLpgSQL_nsitem *nse;
	bool		old_nsstate;
	Oid			classOid;
	HeapTuple	classtup = NULL;
	HeapTuple	attrtup = NULL;
	HeapTuple	typetup = NULL;
	Form_pg_class classStruct;
	Form_pg_attribute attrStruct;
	char	   *cp[3];
	int			i;
	MemoryContext oldCxt;
	int			result = T_ERROR;

	/* Avoid memory leaks in the long-term function context */
	oldCxt = MemoryContextSwitchTo(compile_tmp_cxt);

	/* Do case conversion and word separation */
	/* We convert %type to .type momentarily to keep converter happy */
	i = strlen(word) - 5;
	Assert(word[i] == '%');
	word[i] = '.';
	plpgsql_convert_ident(word, cp, 3);
	word[i] = '%';

	/*
	 * Lookup the first word
	 */
	nse = plpgsql_ns_lookup(cp[0], NULL);

	/*
	 * If this is a label lookup the second word in that label's namestack
	 * level
	 */
	if (nse != NULL)
	{
		if (nse->itemtype == PLPGSQL_NSTYPE_LABEL)
		{
			old_nsstate = plpgsql_ns_setlocal(false);
			nse = plpgsql_ns_lookup(cp[1], cp[0]);
			plpgsql_ns_setlocal(old_nsstate);

			if (nse != NULL && nse->itemtype == PLPGSQL_NSTYPE_VAR)
			{
				plpgsql_yylval.dtype = ((PLpgSQL_var *) (plpgsql_Datums[nse->itemno]))->datatype;
				result = T_DTYPE;
			}
		}

		/* Return T_ERROR if not found, otherwise T_DTYPE */
		goto done;
	}

	/*
	 * First word could also be a table name
	 */
	classOid = RelnameGetRelid(cp[0]);
	if (!OidIsValid(classOid))
		goto done;

	classtup = SearchSysCache(RELOID,
							  ObjectIdGetDatum(classOid),
							  0, 0, 0);
	if (!HeapTupleIsValid(classtup))
		goto done;
	classStruct = (Form_pg_class) GETSTRUCT(classtup);

	/*
	 * It must be a relation, sequence, view, or type
	 */
	if (classStruct->relkind != RELKIND_RELATION &&
		classStruct->relkind != RELKIND_SEQUENCE &&
		classStruct->relkind != RELKIND_VIEW &&
		classStruct->relkind != RELKIND_COMPOSITE_TYPE)
		goto done;

	/*
	 * Fetch the named table field and its type
	 */
	attrtup = SearchSysCacheAttName(classOid, cp[1]);
	if (!HeapTupleIsValid(attrtup))
		goto done;
	attrStruct = (Form_pg_attribute) GETSTRUCT(attrtup);

	typetup = SearchSysCache(TYPEOID,
							 ObjectIdGetDatum(attrStruct->atttypid),
							 0, 0, 0);
	if (!HeapTupleIsValid(typetup))
		elog(ERROR, "cache lookup failed for type %u", attrStruct->atttypid);

	/*
	 * Found that - build a compiler type struct in the caller's cxt and
	 * return it
	 */
	MemoryContextSwitchTo(oldCxt);
	plpgsql_yylval.dtype = build_datatype(typetup, attrStruct->atttypmod);
	MemoryContextSwitchTo(compile_tmp_cxt);
	result = T_DTYPE;

done:
	if (HeapTupleIsValid(classtup))
		ReleaseSysCache(classtup);
	if (HeapTupleIsValid(attrtup))
		ReleaseSysCache(attrtup);
	if (HeapTupleIsValid(typetup))
		ReleaseSysCache(typetup);

	MemoryContextSwitchTo(oldCxt);
	return result;
}

/* ----------
 * plpgsql_parse_tripwordtype		Same lookup for word.word.word%TYPE
 * ----------
 */
#define TYPE_JUNK_LEN	5

int
plpgsql_parse_tripwordtype(char *word)
{
	Oid			classOid;
	HeapTuple	classtup = NULL;
	HeapTuple	attrtup = NULL;
	HeapTuple	typetup = NULL;
	Form_pg_class classStruct;
	Form_pg_attribute attrStruct;
	char	   *cp[2];
	char	   *colname[1];
	int			qualified_att_len;
	int			numdots = 0;
	int			i;
	RangeVar   *relvar;
	MemoryContext oldCxt;
	int			result = T_ERROR;

	/* Avoid memory leaks in the long-term function context */
	oldCxt = MemoryContextSwitchTo(compile_tmp_cxt);

	/* Do case conversion and word separation */
	qualified_att_len = strlen(word) - TYPE_JUNK_LEN;
	Assert(word[qualified_att_len] == '%');

	for (i = 0; i < qualified_att_len; i++)
	{
		if (word[i] == '.' && ++numdots == 2)
			break;
	}

	cp[0] = (char *) palloc((i + 1) * sizeof(char));
	memcpy(cp[0], word, i * sizeof(char));
	cp[0][i] = '\0';

	/*
	 * qualified_att_len - one based position + 1 (null terminator)
	 */
	cp[1] = (char *) palloc((qualified_att_len - i) * sizeof(char));
	memcpy(cp[1], &word[i + 1], (qualified_att_len - i - 1) * sizeof(char));
	cp[1][qualified_att_len - i - 1] = '\0';

	relvar = makeRangeVarFromNameList(stringToQualifiedNameList(cp[0],
											  "plpgsql_parse_tripwordtype"));
	classOid = RangeVarGetRelid(relvar, true);
	if (!OidIsValid(classOid))
		goto done;

	classtup = SearchSysCache(RELOID,
							  ObjectIdGetDatum(classOid),
							  0, 0, 0);
	if (!HeapTupleIsValid(classtup))
		goto done;
	classStruct = (Form_pg_class) GETSTRUCT(classtup);

	/*
	 * It must be a relation, sequence, view, or type
	 */
	if (classStruct->relkind != RELKIND_RELATION &&
		classStruct->relkind != RELKIND_SEQUENCE &&
		classStruct->relkind != RELKIND_VIEW &&
		classStruct->relkind != RELKIND_COMPOSITE_TYPE)
		goto done;

	/*
	 * Fetch the named table field and its type
	 */
	plpgsql_convert_ident(cp[1], colname, 1);
	attrtup = SearchSysCacheAttName(classOid, colname[0]);
	if (!HeapTupleIsValid(attrtup))
		goto done;
	attrStruct = (Form_pg_attribute) GETSTRUCT(attrtup);

	typetup = SearchSysCache(TYPEOID,
							 ObjectIdGetDatum(attrStruct->atttypid),
							 0, 0, 0);
	if (!HeapTupleIsValid(typetup))
		elog(ERROR, "cache lookup failed for type %u", attrStruct->atttypid);

	/*
	 * Found that - build a compiler type struct in the caller's cxt and
	 * return it
	 */
	MemoryContextSwitchTo(oldCxt);
	plpgsql_yylval.dtype = build_datatype(typetup, attrStruct->atttypmod);
	MemoryContextSwitchTo(compile_tmp_cxt);
	result = T_DTYPE;

done:
	if (HeapTupleIsValid(classtup))
		ReleaseSysCache(classtup);
	if (HeapTupleIsValid(attrtup))
		ReleaseSysCache(attrtup);
	if (HeapTupleIsValid(typetup))
		ReleaseSysCache(typetup);

	MemoryContextSwitchTo(oldCxt);
	return result;
}

/* ----------
 * plpgsql_parse_wordrowtype		Scanner found word%ROWTYPE.
 *					So word must be a table name.
 * ----------
 */
int
plpgsql_parse_wordrowtype(char *word)
{
	Oid			classOid;
	char	   *cp[2];
	int			i;

	/* Do case conversion and word separation */
	/* We convert %rowtype to .rowtype momentarily to keep converter happy */
	i = strlen(word) - 8;
	Assert(word[i] == '%');
	word[i] = '.';
	plpgsql_convert_ident(word, cp, 2);
	word[i] = '%';

	/* Lookup the relation */
	classOid = RelnameGetRelid(cp[0]);
	if (!OidIsValid(classOid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_TABLE),
				 errmsg("relation \"%s\" does not exist", cp[0])));

	/*
	 * Build and return the row type struct
	 */
	plpgsql_yylval.dtype = plpgsql_build_datatype(get_rel_type_id(classOid),
												  -1);

	pfree(cp[0]);
	pfree(cp[1]);

	return T_DTYPE;
}

/* ----------
 * plpgsql_parse_dblwordrowtype		Scanner found word.word%ROWTYPE.
 *			So word must be a namespace qualified table name.
 * ----------
 */
#define ROWTYPE_JUNK_LEN	8

int
plpgsql_parse_dblwordrowtype(char *word)
{
	Oid			classOid;
	char	   *cp;
	int			i;
	RangeVar   *relvar;
	MemoryContext oldCxt;

	/* Avoid memory leaks in long-term function context */
	oldCxt = MemoryContextSwitchTo(compile_tmp_cxt);

	/* Do case conversion and word separation */
	/* We convert %rowtype to .rowtype momentarily to keep converter happy */
	i = strlen(word) - ROWTYPE_JUNK_LEN;
	Assert(word[i] == '%');
	word[i] = '\0';
	cp = pstrdup(word);
	word[i] = '%';

	/* Lookup the relation */
	relvar = makeRangeVarFromNameList(stringToQualifiedNameList(cp, "plpgsql_parse_dblwordrowtype"));
	classOid = RangeVarGetRelid(relvar, true);
	if (!OidIsValid(classOid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_TABLE),
				 errmsg("relation \"%s\" does not exist", cp)));

	/* Build and return the row type struct */
	plpgsql_yylval.dtype = plpgsql_build_datatype(get_rel_type_id(classOid),
												  -1);

	MemoryContextSwitchTo(oldCxt);
	return T_DTYPE;
}

/*
 * plpgsql_build_variable - build a datum-array entry of a given
 * datatype
 *
 * The returned struct may be a PLpgSQL_var, PLpgSQL_row, or
 * PLpgSQL_rec depending on the given datatype, and is allocated via
 * palloc.	The struct is automatically added to the current datum
 * array, and optionally to the current namespace.
 */
PLpgSQL_variable *
plpgsql_build_variable(const char *refname, int lineno, PLpgSQL_type *dtype,
					   bool add2namespace)
{
	PLpgSQL_variable *result;

	switch (dtype->ttype)
	{
		case PLPGSQL_TTYPE_SCALAR:
			{
				/* Ordinary scalar datatype */
				PLpgSQL_var *var;

				var = palloc0(sizeof(PLpgSQL_var));
				var->dtype = PLPGSQL_DTYPE_VAR;
				var->refname = pstrdup(refname);
				var->lineno = lineno;
				var->datatype = dtype;
				/* other fields might be filled by caller */

				/* preset to NULL */
				var->value = 0;
				var->isnull = true;
				var->freeval = false;

				plpgsql_adddatum((PLpgSQL_datum *) var);
				if (add2namespace)
					plpgsql_ns_additem(PLPGSQL_NSTYPE_VAR,
									   var->varno,
									   refname);
				result = (PLpgSQL_variable *) var;
				break;
			}
		case PLPGSQL_TTYPE_ROW:
			{
				/* Composite type -- build a row variable */
				PLpgSQL_row *row;

				row = build_row_from_class(dtype->typrelid);

				row->dtype = PLPGSQL_DTYPE_ROW;
				row->refname = pstrdup(refname);
				row->lineno = lineno;

				plpgsql_adddatum((PLpgSQL_datum *) row);
				if (add2namespace)
					plpgsql_ns_additem(PLPGSQL_NSTYPE_ROW,
									   row->rowno,
									   refname);
				result = (PLpgSQL_variable *) row;
				break;
			}
		case PLPGSQL_TTYPE_REC:
			{
				/*
				 * "record" type -- build a variable-contents record variable
				 */
				PLpgSQL_rec *rec;

				rec = palloc0(sizeof(PLpgSQL_rec));
				rec->dtype = PLPGSQL_DTYPE_REC;
				rec->refname = pstrdup(refname);
				rec->lineno = lineno;

				plpgsql_adddatum((PLpgSQL_datum *) rec);
				if (add2namespace)
					plpgsql_ns_additem(PLPGSQL_NSTYPE_REC,
									   rec->recno,
									   refname);
				result = (PLpgSQL_variable *) rec;
				break;
			}
		case PLPGSQL_TTYPE_PSEUDO:
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("variable \"%s\" has pseudo-type %s",
							refname, format_type_be(dtype->typoid))));
			result = NULL;		/* keep compiler quiet */
			break;