pl_comp.c

来自「postgresql8.3.4源码,开源数据库」· C语言 代码 · 共 2,081 行 · 第 1/4 页

				if (rettypeid == VOIDOID ||
					rettypeid == RECORDOID)
					 /* okay */ ;
				else if (rettypeid == TRIGGEROID)
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("trigger functions can only be called as triggers")));
				else
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("plpgsql functions cannot return type %s",
									format_type_be(rettypeid))));
			}

			if (typeStruct->typrelid != InvalidOid ||
				rettypeid == RECORDOID)
				function->fn_retistuple = true;
			else
			{
				function->fn_retbyval = typeStruct->typbyval;
				function->fn_rettyplen = typeStruct->typlen;
				function->fn_rettypioparam = getTypeIOParam(typeTup);
				fmgr_info(typeStruct->typinput, &(function->fn_retinput));

				/*
				 * install $0 reference, but only for polymorphic return
				 * types, and not when the return is specified through an
				 * output parameter.
				 */
				if (IsPolymorphicType(procStruct->prorettype) &&
					num_out_args == 0)
				{
					(void) plpgsql_build_variable("$0", 0,
												  build_datatype(typeTup, -1),
												  true);
				}
			}
			ReleaseSysCache(typeTup);
			break;

		case T_TRIGGER:
			/* Trigger procedure's return type is unknown yet */
			function->fn_rettype = InvalidOid;
			function->fn_retbyval = false;
			function->fn_retistuple = true;
			function->fn_retset = false;

			/* shouldn't be any declared arguments */
			if (procStruct->pronargs != 0)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				  errmsg("trigger functions cannot have declared arguments"),
						 errhint("You probably want to use TG_NARGS and TG_ARGV instead.")));

			/* Add the record for referencing NEW */
			rec = palloc0(sizeof(PLpgSQL_rec));
			rec->dtype = PLPGSQL_DTYPE_REC;
			rec->refname = pstrdup("new");
			rec->tup = NULL;
			rec->tupdesc = NULL;
			rec->freetup = false;
			plpgsql_adddatum((PLpgSQL_datum *) rec);
			plpgsql_ns_additem(PLPGSQL_NSTYPE_REC, rec->recno, rec->refname);
			function->new_varno = rec->recno;

			/* Add the record for referencing OLD */
			rec = palloc0(sizeof(PLpgSQL_rec));
			rec->dtype = PLPGSQL_DTYPE_REC;
			rec->refname = pstrdup("old");
			rec->tup = NULL;
			rec->tupdesc = NULL;
			rec->freetup = false;
			plpgsql_adddatum((PLpgSQL_datum *) rec);
			plpgsql_ns_additem(PLPGSQL_NSTYPE_REC, rec->recno, rec->refname);
			function->old_varno = rec->recno;

			/* Add the variable tg_name */
			var = plpgsql_build_variable("tg_name", 0,
										 plpgsql_build_datatype(NAMEOID, -1),
										 true);
			function->tg_name_varno = var->dno;

			/* Add the variable tg_when */
			var = plpgsql_build_variable("tg_when", 0,
										 plpgsql_build_datatype(TEXTOID, -1),
										 true);
			function->tg_when_varno = var->dno;

			/* Add the variable tg_level */
			var = plpgsql_build_variable("tg_level", 0,
										 plpgsql_build_datatype(TEXTOID, -1),
										 true);
			function->tg_level_varno = var->dno;

			/* Add the variable tg_op */
			var = plpgsql_build_variable("tg_op", 0,
										 plpgsql_build_datatype(TEXTOID, -1),
										 true);
			function->tg_op_varno = var->dno;

			/* Add the variable tg_relid */
			var = plpgsql_build_variable("tg_relid", 0,
										 plpgsql_build_datatype(OIDOID, -1),
										 true);
			function->tg_relid_varno = var->dno;

			/* Add the variable tg_relname */
			var = plpgsql_build_variable("tg_relname", 0,
										 plpgsql_build_datatype(NAMEOID, -1),
										 true);
			function->tg_relname_varno = var->dno;

			/* tg_table_name is now preferred to tg_relname */
			var = plpgsql_build_variable("tg_table_name", 0,
										 plpgsql_build_datatype(NAMEOID, -1),
										 true);
			function->tg_table_name_varno = var->dno;


			/* add variable tg_table_schema */
			var = plpgsql_build_variable("tg_table_schema", 0,
										 plpgsql_build_datatype(NAMEOID, -1),
										 true);
			function->tg_table_schema_varno = var->dno;


			/* Add the variable tg_nargs */
			var = plpgsql_build_variable("tg_nargs", 0,
										 plpgsql_build_datatype(INT4OID, -1),
										 true);
			function->tg_nargs_varno = var->dno;

			break;

		default:
			elog(ERROR, "unrecognized function typecode: %u", functype);
			break;
	}

	/* Remember if function is STABLE/IMMUTABLE */
	function->fn_readonly = (procStruct->provolatile != PROVOLATILE_VOLATILE);

	/*
	 * Create the magic FOUND variable.
	 */
	var = plpgsql_build_variable("found", 0,
								 plpgsql_build_datatype(BOOLOID, -1),
								 true);
	function->found_varno = var->dno;

	/*
	 * Now parse the function's text
	 */
	parse_rc = plpgsql_yyparse();
	if (parse_rc != 0)
		elog(ERROR, "plpgsql parser returned %d", parse_rc);
	function->action = plpgsql_yylval.program;

	plpgsql_scanner_finish();
	pfree(proc_source);

	/*
	 * If it has OUT parameters or returns VOID or returns a set, we allow
	 * control to fall off the end without an explicit RETURN statement. The
	 * easiest way to implement this is to add a RETURN statement to the end
	 * of the statement list during parsing.  However, if the outer block has
	 * an EXCEPTION clause, we need to make a new outer block, since the added
	 * RETURN shouldn't act like it is inside the EXCEPTION clause.
	 */
	if (num_out_args > 0 || function->fn_rettype == VOIDOID ||
		function->fn_retset)
	{
		if (function->action->exceptions != NULL)
		{
			PLpgSQL_stmt_block *new;

			new = palloc0(sizeof(PLpgSQL_stmt_block));
			new->cmd_type = PLPGSQL_STMT_BLOCK;
			new->body = list_make1(function->action);

			function->action = new;
		}
		if (function->action->body == NIL ||
			((PLpgSQL_stmt *) llast(function->action->body))->cmd_type != PLPGSQL_STMT_RETURN)
		{
			PLpgSQL_stmt_return *new;

			new = palloc0(sizeof(PLpgSQL_stmt_return));
			new->cmd_type = PLPGSQL_STMT_RETURN;
			new->expr = NULL;
			new->retvarno = function->out_param_varno;

			function->action->body = lappend(function->action->body, new);
		}
	}

	/*
	 * Complete the function's info
	 */
	function->fn_nargs = procStruct->pronargs;
	for (i = 0; i < function->fn_nargs; i++)
		function->fn_argvarnos[i] = in_arg_varnos[i];
	function->ndatums = plpgsql_nDatums;
	function->datums = palloc(sizeof(PLpgSQL_datum *) * plpgsql_nDatums);
	for (i = 0; i < plpgsql_nDatums; i++)
		function->datums[i] = plpgsql_Datums[i];

	/* Debug dump for completed functions */
	if (plpgsql_DumpExecTree)
		plpgsql_dumptree(function);

	/*
	 * add it to the hash table
	 */
	plpgsql_HashTableInsert(function, hashkey);

	/*
	 * Pop the error context stack
	 */
	error_context_stack = plerrcontext.previous;
	plpgsql_error_funcname = NULL;
	plpgsql_error_lineno = 0;

	plpgsql_check_syntax = false;

	MemoryContextSwitchTo(compile_tmp_cxt);
	compile_tmp_cxt = NULL;
	return function;
}


/*
 * error context callback to let us supply a call-stack traceback. If
 * we are validating, the function source is passed as an
 * argument. This function is public only for the sake of an assertion
 * in gram.y
 */
void
plpgsql_compile_error_callback(void *arg)
{
	if (arg)
	{
		/*
		 * Try to convert syntax error position to reference text of original
		 * CREATE FUNCTION command.
		 */
		if (function_parse_error_transpose((const char *) arg))
			return;

		/*
		 * Done if a syntax error position was reported; otherwise we have to
		 * fall back to a "near line N" report.
		 */
	}

	if (plpgsql_error_funcname)
		errcontext("compile of PL/pgSQL function \"%s\" near line %d",
				   plpgsql_error_funcname, plpgsql_error_lineno);
}


/* ----------
 * plpgsql_parse_word		The scanner calls this to postparse
 *				any single word not found by a
 *				keyword rule.
 * ----------
 */
int
plpgsql_parse_word(const char *word)
{
	PLpgSQL_nsitem *nse;
	char	   *cp[1];

	/* Do case conversion and word separation */
	plpgsql_convert_ident(word, cp, 1);

	/*
	 * Recognize tg_argv when compiling triggers
	 * (XXX this sucks, it should be a regular variable in the namestack)
	 */
	if (plpgsql_curr_compile->fn_functype == T_TRIGGER)
	{
		if (strcmp(cp[0], "tg_argv") == 0)
		{
			bool		save_spacescanned = plpgsql_SpaceScanned;
			PLpgSQL_trigarg *trigarg;

			trigarg = palloc0(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.scalar = (PLpgSQL_datum *) trigarg;

			plpgsql_SpaceScanned = save_spacescanned;
			pfree(cp[0]);
			return T_SCALAR;
		}
	}

	/*
	 * Do a lookup on the compiler's namestack
	 */
	nse = plpgsql_ns_lookup(cp[0], NULL, NULL, NULL);
	pfree(cp[0]);

	if (nse != NULL)
	{
		switch (nse->itemtype)
		{
			case PLPGSQL_NSTYPE_VAR:
				plpgsql_yylval.scalar = plpgsql_Datums[nse->itemno];
				return T_SCALAR;

			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;
		}
	}

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


/* ----------
 * plpgsql_parse_dblword		Same lookup for two words
 *					separated by a dot.
 * ----------
 */
int
plpgsql_parse_dblword(const char *word)
{
	PLpgSQL_nsitem *ns;
	char	   *cp[2];
	int			nnames;

	/* Do case conversion and word separation */
	plpgsql_convert_ident(word, cp, 2);

	/*
	 * Do a lookup on the compiler's namestack
	 */
	ns = plpgsql_ns_lookup(cp[0], cp[1], NULL, &nnames);
	if (ns == NULL)
	{
		pfree(cp[0]);
		pfree(cp[1]);
		return T_ERROR;
	}

	switch (ns->itemtype)
	{
		case PLPGSQL_NSTYPE_VAR:
			/* Block-qualified reference to scalar variable. */
			plpgsql_yylval.scalar = plpgsql_Datums[ns->itemno];
			pfree(cp[0]);
			pfree(cp[1]);
			return T_SCALAR;

		case PLPGSQL_NSTYPE_REC:
			if (nnames == 1)
			{
				/*
				 * First word is a record name, so second 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[1]);
				new->recparentno = ns->itemno;

				plpgsql_adddatum((PLpgSQL_datum *) new);

				plpgsql_yylval.scalar = (PLpgSQL_datum *) new;

				pfree(cp[0]);
				pfree(cp[1]);
				return T_SCALAR;
			}
			else
			{
				/* Block-qualified reference to record variable. */
				plpgsql_yylval.rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]);
				pfree(cp[0]);
				pfree(cp[1]);
				return T_RECORD;
			}

		case PLPGSQL_NSTYPE_ROW:
			if (nnames == 1)
			{
				/*
				 * 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 (row->fieldnames[i] &&
						strcmp(row->fieldnames[i], cp[1]) == 0)
					{
						plpgsql_yylval.scalar = plpgsql_Datums[row->varnos[i]];
						pfree(cp[0]);
						pfree(cp[1]);
						return T_SCALAR;
					}
				}
				ereport(ERROR,
						(errcode(ERRCODE_UNDEFINED_COLUMN),
						 errmsg("row \"%s\" has no field \"%s\"",
								cp[0], cp[1])));
			}
			else
			{
				/* Block-qualified reference to row variable. */
				plpgsql_yylval.row = (PLpgSQL_row *) (plpgsql_Datums[ns->itemno]);
				pfree(cp[0]);
				pfree(cp[1]);
				return T_ROW;
			}

		default:
			break;
	}

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


/* ----------
 * plpgsql_parse_tripword		Same lookup for three words
 *					separated by dots.
 * ----------
 */
int
plpgsql_parse_tripword(const char *word)
{
	PLpgSQL_nsitem *ns;
	char	   *cp[3];
	int			nnames;

	/* Do case conversion and word separation */
	plpgsql_convert_ident(word, cp, 3);

	/*
	 * Do a lookup on the compiler's namestack.
	 * Must find a qualified reference.
	 */
	ns = plpgsql_ns_lookup(cp[0], cp[1], cp[2], &nnames);
	if (ns == NULL || nnames != 2)
	{
		pfree(cp[0]);
		pfree(cp[1]);
		pfree(cp[2]);
		return T_ERROR;
	}

	switch (ns->itemtype)
	{
		case PLPGSQL_NSTYPE_REC:
			{
				/*
				 * words 1/2 are 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:
			{
				/*
				 * words 1/2 are 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]];