pl_comp.c

来自「关系型数据库 Postgresql 6.5.2」· C语言 代码 · 共 1,370 行 · 第 1/3 页

	/* ----------
	 * Create the magic found variable indicating if the
	 * last FOR or SELECT statement returned data
	 * ----------
	 */
	var = malloc(sizeof(PLpgSQL_var));
	memset(var, 0, sizeof(PLpgSQL_var));

	var->dtype = PLPGSQL_DTYPE_VAR;
	var->refname = strdup("found");
	var->lineno = 0;
	plpgsql_parse_word("bool");
	var->datatype = plpgsql_yylval.dtype;
	var->isconst = false;
	var->notnull = false;
	var->default_val = NULL;

	plpgsql_adddatum((PLpgSQL_datum *) var);
	plpgsql_ns_additem(PLPGSQL_NSTYPE_VAR, var->varno, strdup("found"));
	function->found_varno = var->varno;

	/* ----------
	 * Forget about the above created variables
	 * ----------
	 */
	plpgsql_add_initdatums(NULL);

	/* ----------
	 * Now parse the functions text
	 * ----------
	 */
	parse_rc = plpgsql_yyparse();
	if (parse_rc != 0)
	{
		plpgsql_comperrinfo();
		elog(ERROR, "plpgsql: parser returned %d ???", parse_rc);
	}

	/* ----------
	 * If that was successful, complete the functions info.
	 * ----------
	 */
	function->fn_nargs = procStruct->pronargs;
	for (i = 0; i < function->fn_nargs; i++)
		function->fn_argvarnos[i] = arg_varnos[i];
	function->ndatums = plpgsql_nDatums;
	function->datums = malloc(sizeof(PLpgSQL_datum *) * plpgsql_nDatums);
	for (i = 0; i < plpgsql_nDatums; i++)
		function->datums[i] = plpgsql_Datums[i];
	function->action = plpgsql_yylval.program;


	/* ----------
	 * Finally return the compiled function
	 * ----------
	 */
	if (plpgsql_DumpExecTree)
		plpgsql_dumptree(function);
	return function;
}


/* ----------
 * plpgsql_parse_word		The scanner calls this to postparse
 *				any single word not found by a
 *				keyword rule.
 * ----------
 */
int
plpgsql_parse_word(char *word)
{
	PLpgSQL_nsitem *nse;
	char	   *cp;
	HeapTuple	typeTup;
	Form_pg_type typeStruct;
	char	   *typeXlated;

	/* ----------
	 * We do our lookups case insensitive
	 * ----------
	 */
	cp = plpgsql_tolower(word);

	/* ----------
	 * Special handling when compiling triggers
	 * ----------
	 */
	if (plpgsql_curr_compile->fn_functype == T_TRIGGER)
	{
		if (!strcmp(cp, "tg_argv"))
		{
			int			save_spacescanned = plpgsql_SpaceScanned;
			PLpgSQL_trigarg *trigarg;

			trigarg = malloc(sizeof(PLpgSQL_trigarg));
			memset(trigarg, 0, sizeof(PLpgSQL_trigarg));
			trigarg->dtype = PLPGSQL_DTYPE_TRIGARG;

			if (plpgsql_yylex() != '[')
				plpgsql_yyerror("expected [");

			trigarg->argnum = plpgsql_read_expression(']', "]");

			plpgsql_adddatum((PLpgSQL_datum *) trigarg);
			plpgsql_yylval.trigarg = trigarg;

			plpgsql_SpaceScanned = save_spacescanned;
			return T_TGARGV;
		}
	}

	/* ----------
	 * Do a lookup on the compilers namestack
	 * ----------
	 */
	nse = plpgsql_ns_lookup(cp, NULL);
	if (nse != NULL)
	{
		pfree(cp);
		switch (nse->itemtype)
		{
			case PLPGSQL_NSTYPE_LABEL:
				return T_LABEL;

			case PLPGSQL_NSTYPE_VAR:
				plpgsql_yylval.var = (PLpgSQL_var *) (plpgsql_Datums[nse->itemno]);
				return T_VARIABLE;

			case PLPGSQL_NSTYPE_REC:
				plpgsql_yylval.rec = (PLpgSQL_rec *) (plpgsql_Datums[nse->itemno]);
				return T_RECORD;

			case PLPGSQL_NSTYPE_ROW:
				plpgsql_yylval.row = (PLpgSQL_row *) (plpgsql_Datums[nse->itemno]);
				return T_ROW;

			default:
				return T_ERROR;
		}
	}

	/* ----------
	 * Try to find a data type with that name, but ignore
	 * pg_type entries that are in fact class types.
	 * ----------
	 */
	typeXlated = xlateSqlType(cp);
	typeTup = SearchSysCacheTuple(TYPNAME,
								  PointerGetDatum(typeXlated), 0, 0, 0);
	if (HeapTupleIsValid(typeTup))
	{
		PLpgSQL_type *typ;

		typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

		if (typeStruct->typrelid != InvalidOid)
		{
			pfree(cp);
			return T_WORD;
		}

		typ = (PLpgSQL_type *) malloc(sizeof(PLpgSQL_type));

		typ->typname = strdup(nameout(&(typeStruct->typname)));
		typ->typoid = typeTup->t_data->t_oid;
		fmgr_info(typeStruct->typinput, &(typ->typinput));
		typ->typbyval = typeStruct->typbyval;
		typ->atttypmod = -1;

		plpgsql_yylval.dtype = typ;

		pfree(cp);
		return T_DTYPE;
	}

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


/* ----------
 * plpgsql_parse_dblword		Same lookup for two words
 *					separated by a dot.
 * ----------
 */
int
plpgsql_parse_dblword(char *string)
{
	char	   *word1;
	char	   *word2;
	PLpgSQL_nsitem *ns;

	/* ----------
	 * Convert to lower case and separate the words
	 * ----------
	 */
	word1 = plpgsql_tolower(string);
	word2 = strchr(word1, '.');
	*word2++ = '\0';

	/* ----------
	 * Lookup the first word
	 * ----------
	 */
	ns = plpgsql_ns_lookup(word1, NULL);
	if (ns == NULL)
	{
		pfree(word1);
		return T_ERROR;
	}

	switch (ns->itemtype)
	{
		case PLPGSQL_NSTYPE_LABEL:
			/* ----------
			 * First word is a label, so second word could be
			 * a variable, record or row in that bodies namestack.
			 * Anything else could only be something in a query
			 * given to the SPI manager and T_ERROR will get eaten
			 * up by the collector routines.
			 * ----------
			 */
			ns = plpgsql_ns_lookup(word2, word1);
			if (ns == NULL)
			{
				pfree(word1);
				return T_ERROR;
			}
			switch (ns->itemtype)
			{
				case PLPGSQL_NSTYPE_VAR:
					plpgsql_yylval.var = (PLpgSQL_var *) (plpgsql_Datums[ns->itemno]);
					pfree(word1);
					return T_VARIABLE;

				case PLPGSQL_NSTYPE_REC:
					plpgsql_yylval.rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]);
					pfree(word1);
					return T_RECORD;

				case PLPGSQL_NSTYPE_ROW:
					plpgsql_yylval.row = (PLpgSQL_row *) (plpgsql_Datums[ns->itemno]);
					pfree(word1);
					return T_ROW;

				default:
					pfree(word1);
					return T_ERROR;
			}

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

				new = malloc(sizeof(PLpgSQL_recfield));
				new->dtype = PLPGSQL_DTYPE_RECFIELD;
				new->fieldname = strdup(word2);
				new->recno = ns->itemno;

				plpgsql_adddatum((PLpgSQL_datum *) new);

				pfree(word1);
				plpgsql_yylval.recfield = new;
				return T_RECFIELD;
			}

		case PLPGSQL_NSTYPE_ROW:
			{
				/* ----------
				 * First word is a row name, so second 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 (!strcmp(row->fieldnames[i], word2))
					{
						plpgsql_yylval.var = (PLpgSQL_var *) (plpgsql_Datums[row->varnos[i]]);
						pfree(word1);
						return T_VARIABLE;
					}
				}
				plpgsql_comperrinfo();
				elog(ERROR, "row %s doesn't have a field %s",
					 word1, word2);
			}

		default:
			break;
	}

	pfree(word1);
	return T_ERROR;
}


/* ----------
 * plpgsql_parse_tripword		Same lookup for three words
 *					separated by dots.
 * ----------
 */
int
plpgsql_parse_tripword(char *string)
{
	char	   *word1;
	char	   *word2;
	char	   *word3;
	PLpgSQL_nsitem *ns;

	/* ----------
	 * Convert to lower case and separate the words
	 * ----------
	 */
	word1 = plpgsql_tolower(string);
	word2 = strchr(word1, '.');
	*word2++ = '\0';
	word3 = strchr(word2, '.');
	*word3++ = '\0';

	/* ----------
	 * Lookup the first word - it must be a label
	 * ----------
	 */
	ns = plpgsql_ns_lookup(word1, NULL);
	if (ns == NULL)
	{
		pfree(word1);
		return T_ERROR;
	}
	if (ns->itemtype != PLPGSQL_NSTYPE_LABEL)
	{
		pfree(word1);
		return T_ERROR;
	}

	/* ----------
	 * First word is a label, so second word could be
	 * a record or row
	 * ----------
	 */
	ns = plpgsql_ns_lookup(word2, word1);
	if (ns == NULL)
	{
		pfree(word1);
		return T_ERROR;
	}

	switch (ns->itemtype)
	{
		case PLPGSQL_NSTYPE_REC:
			{
				/* ----------
				 * This word is a record name, so third word
				 * must be a field in this record.
				 * ----------
				 */
				PLpgSQL_recfield *new;

				new = malloc(sizeof(PLpgSQL_recfield));
				new->dtype = PLPGSQL_DTYPE_RECFIELD;
				new->fieldname = strdup(word3);
				new->recno = ns->itemno;

				plpgsql_adddatum((PLpgSQL_datum *) new);

				pfree(word1);
				plpgsql_yylval.recfield = new;
				return T_RECFIELD;
			}

		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 (!strcmp(row->fieldnames[i], word3))
					{
						plpgsql_yylval.var = (PLpgSQL_var *) (plpgsql_Datums[row->varnos[i]]);
						pfree(word1);
						return T_VARIABLE;
					}
				}
				plpgsql_comperrinfo();
				elog(ERROR, "row %s.%s doesn't have a field %s",
					 word1, word2, word3);
			}

		default:
			break;
	}

	pfree(word1);
	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;
	char	   *cp;
	HeapTuple	typeTup;
	Form_pg_type typeStruct;
	char	   *typeXlated;
	bool		old_nsstate;

	/* ----------
	 * We do our lookups case insensitive
	 * ----------
	 */
	cp = plpgsql_tolower(word);
	*(strchr(cp, '%')) = '\0';

	/* ----------
	 * Do a lookup on the compilers namestack.
	 * But ensure it moves up to the toplevel.
	 * ----------
	 */
	old_nsstate = plpgsql_ns_setlocal(false);
	nse = plpgsql_ns_lookup(cp, NULL);
	plpgsql_ns_setlocal(old_nsstate);

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