pl_comp.c

关系型数据库 Postgresql 6.5.2

/**********************************************************************
 * pl_comp.c		- Compiler part of the PL/pgSQL
 *			  procedural language
 *
 * IDENTIFICATION
 *	  $Header: /usr/local/cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.7 1999/05/25 16:15:17 momjian Exp $
 *
 *	  This software is copyrighted by Jan Wieck - Hamburg.
 *
 *	  The author hereby grants permission  to  use,  copy,	modify,
 *	  distribute,  and	license this software and its documentation
 *	  for any purpose, provided that existing copyright notices are
 *	  retained	in	all  copies  and  that	this notice is included
 *	  verbatim in any distributions. No written agreement, license,
 *	  or  royalty  fee	is required for any of the authorized uses.
 *	  Modifications to this software may be  copyrighted  by  their
 *	  author  and  need  not  follow  the licensing terms described
 *	  here, provided that the new terms are  clearly  indicated  on
 *	  the first page of each file where they apply.
 *
 *	  IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY
 *	  PARTY  FOR  DIRECT,	INDIRECT,	SPECIAL,   INCIDENTAL,	 OR
 *	  CONSEQUENTIAL   DAMAGES  ARISING	OUT  OF  THE  USE  OF  THIS
 *	  SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN
 *	  IF  THE  AUTHOR  HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
 *	  DAMAGE.
 *
 *	  THE  AUTHOR  AND	DISTRIBUTORS  SPECIFICALLY	 DISCLAIM	ANY
 *	  WARRANTIES,  INCLUDING,  BUT	NOT  LIMITED  TO,  THE	IMPLIED
 *	  WARRANTIES  OF  MERCHANTABILITY,	FITNESS  FOR  A  PARTICULAR
 *	  PURPOSE,	AND NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON
 *	  AN "AS IS" BASIS, AND THE AUTHOR	AND  DISTRIBUTORS  HAVE  NO
 *	  OBLIGATION   TO	PROVIDE   MAINTENANCE,	 SUPPORT,  UPDATES,
 *	  ENHANCEMENTS, OR MODIFICATIONS.
 *
 **********************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <ctype.h>

#include "plpgsql.h"
#include "pl.tab.h"

#include "executor/spi.h"
#include "commands/trigger.h"
#include "utils/elog.h"
#include "utils/builtins.h"
#include "fmgr.h"
#include "access/heapam.h"

#include "utils/syscache.h"
#include "utils/catcache.h"
#include "catalog/catname.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "catalog/pg_class.h"
#include "catalog/pg_attribute.h"
#include "catalog/pg_attrdef.h"


/* ----------
 * Variables in the parser that shouldn't go into plpgsql.h
 * ----------
 */
extern PLPGSQL_YYSTYPE plpgsql_yylval;
extern int	plpgsql_yylineno;
extern char plpgsql_yytext[];

void		plpgsql_yyerror(const char *s);

/* ----------
 * Our own local and global variables
 * ----------
 */
static int	datums_alloc;
int			plpgsql_nDatums;
PLpgSQL_datum **plpgsql_Datums;
static int	datums_last = 0;

int			plpgsql_error_lineno;
char	   *plpgsql_error_funcname;
int			plpgsql_DumpExecTree = 0;

PLpgSQL_function *plpgsql_curr_compile;


/* ----------
 * Local function declarations
 * ----------
 */
static char *xlateSqlType(char *name);


/* ----------
 * plpgsql_compile		Given a pg_proc's oid, make
 *				an execution tree for it.
 * ----------
 */
PLpgSQL_function *
plpgsql_compile(Oid fn_oid, int functype)
{
	int			parse_rc;
	HeapTuple	procTup;
	Form_pg_proc procStruct;
	HeapTuple	typeTup;
	Form_pg_type typeStruct;
	char	   *proc_source;
	PLpgSQL_function *function;
	PLpgSQL_var *var;
	PLpgSQL_row *row;
	PLpgSQL_rec *rec;
	int			i;
	int			arg_varnos[MAXFMGRARGS];

	/* ----------
	 * Initialize the compiler
	 * ----------
	 */
	plpgsql_ns_init();
	plpgsql_ns_push(NULL);
	plpgsql_DumpExecTree = 0;

	datums_alloc = 128;
	plpgsql_nDatums = 0;
	plpgsql_Datums = palloc(sizeof(PLpgSQL_datum *) * datums_alloc);
	datums_last = 0;

	/* ----------
	 * Lookup the pg_proc tuple by Oid
	 * ----------
	 */
	procTup = SearchSysCacheTuple(PROOID,
								  ObjectIdGetDatum(fn_oid),
								  0, 0, 0);
	if (!HeapTupleIsValid(procTup))
		elog(ERROR, "plpgsql: cache lookup from pg_proc failed");

	/* ----------
	 * Setup the scanner input and error info
	 * ----------
	 */
	procStruct = (Form_pg_proc) GETSTRUCT(procTup);
	proc_source = textout(&(procStruct->prosrc));
	plpgsql_setinput(proc_source, functype);
	plpgsql_error_funcname = nameout(&(procStruct->proname));
	plpgsql_error_lineno = 0;

	/* ----------
	 * Create the new function node
	 * ----------
	 */
	function = malloc(sizeof(PLpgSQL_function));
	memset(function, 0, sizeof(PLpgSQL_function));
	plpgsql_curr_compile = function;

	function->fn_functype = functype;
	function->fn_oid = fn_oid;
	function->fn_name = strdup(nameout(&(procStruct->proname)));

	switch (functype)
	{
		case T_FUNCTION:
			/* ----------
			 * Normal function has a defined returntype
			 * ----------
			 */
			function->fn_rettype = procStruct->prorettype;
			function->fn_retset = procStruct->proretset;

			/* ----------
			 * Lookup the functions return type
			 * ----------
			 */
			typeTup = SearchSysCacheTuple(TYPOID,
					  ObjectIdGetDatum(procStruct->prorettype), 0, 0, 0);

			if (!HeapTupleIsValid(typeTup))
			{
				plpgsql_comperrinfo();
				elog(ERROR, "cache lookup for return type %u failed",
					 procStruct->prorettype);
			}
			typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
			if (typeStruct->typrelid != InvalidOid)
				function->fn_retistuple = true;
			else
			{
				function->fn_retbyval = typeStruct->typbyval;
				function->fn_rettyplen = typeStruct->typlen;
				fmgr_info(typeStruct->typinput, &(function->fn_retinput));
			}

			/* ----------
			 * Create the variables for the procedures parameters
			 * ----------
			 */
			for (i = 0; i < procStruct->pronargs; i++)
			{
				char		buf[256];

				/* ----------
				 * Get the parameters type
				 * ----------
				 */
				typeTup = SearchSysCacheTuple(TYPOID,
				  ObjectIdGetDatum(procStruct->proargtypes[i]), 0, 0, 0);

				if (!HeapTupleIsValid(typeTup))
				{
					plpgsql_comperrinfo();
					elog(ERROR, "cache lookup for argument type %u failed",
						 procStruct->proargtypes[i]);
				}
				typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

				if (typeStruct->typrelid != InvalidOid)
				{
					/* ----------
					 * For tuple type parameters, we set up a record
					 * of that type
					 * ----------
					 */
					sprintf(buf, "%s%%rowtype", nameout(&(typeStruct->typname)));
					if (plpgsql_parse_wordrowtype(buf) != T_ROW)
					{
						plpgsql_comperrinfo();
						elog(ERROR, "cannot get tuple struct of argument %d", i + 1);
					}

					row = plpgsql_yylval.row;
					sprintf(buf, "$%d", i + 1);

					row->refname = strdup(buf);

					plpgsql_adddatum((PLpgSQL_datum *) row);
					plpgsql_ns_additem(PLPGSQL_NSTYPE_ROW, row->rowno, buf);

					arg_varnos[i] = row->rowno;
				}
				else
				{
					/* ----------
					 * Normal parameters get a var node
					 * ----------
					 */
					var = malloc(sizeof(PLpgSQL_var));
					memset(var, 0, sizeof(PLpgSQL_var));
					var->datatype = malloc(sizeof(PLpgSQL_type));
					memset(var->datatype, 0, sizeof(PLpgSQL_type));

					sprintf(buf, "$%d", i + 1);
					var->dtype = PLPGSQL_DTYPE_VAR;
					var->refname = strdup(buf);
					var->lineno = 0;
					var->datatype->typname = strdup(nameout(&(typeStruct->typname)));
					var->datatype->typoid = procStruct->proargtypes[i];
					fmgr_info(typeStruct->typinput, &(var->datatype->typinput));
					var->datatype->typbyval = typeStruct->typbyval;
					var->datatype->atttypmod = -1;
					var->isconst = true;
					var->notnull = false;
					var->default_val = NULL;

					plpgsql_adddatum((PLpgSQL_datum *) var);
					plpgsql_ns_additem(PLPGSQL_NSTYPE_VAR, var->varno, buf);

					arg_varnos[i] = var->varno;
				}
			}
			break;

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

			/* ----------
			 * Add the record for referencing NEW
			 * ----------
			 */
			rec = malloc(sizeof(PLpgSQL_rec));
			memset(rec, 0, sizeof(PLpgSQL_rec));
			rec->dtype = PLPGSQL_DTYPE_REC;
			rec->refname = strdup("new");
			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 = malloc(sizeof(PLpgSQL_rec));
			memset(rec, 0, sizeof(PLpgSQL_rec));
			rec->dtype = PLPGSQL_DTYPE_REC;
			rec->refname = strdup("old");
			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 = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_name");
			var->lineno = 0;
			plpgsql_parse_word("name");
			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, var->refname);
			function->tg_name_varno = var->varno;

			/* ----------
			 * Add the variable tg_when
			 * ----------
			 */
			var = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_when");
			var->lineno = 0;
			plpgsql_parse_word("text");
			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, var->refname);
			function->tg_when_varno = var->varno;

			/* ----------
			 * Add the variable tg_level
			 * ----------
			 */
			var = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_level");
			var->lineno = 0;
			plpgsql_parse_word("text");
			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, var->refname);
			function->tg_level_varno = var->varno;

			/* ----------
			 * Add the variable tg_op
			 * ----------
			 */
			var = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_op");
			var->lineno = 0;
			plpgsql_parse_word("text");
			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, var->refname);
			function->tg_op_varno = var->varno;

			/* ----------
			 * Add the variable tg_relid
			 * ----------
			 */
			var = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_relid");
			var->lineno = 0;
			plpgsql_parse_word("oid");
			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, var->refname);
			function->tg_relid_varno = var->varno;

			/* ----------
			 * Add the variable tg_relname
			 * ----------
			 */
			var = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_relname");
			var->lineno = 0;
			plpgsql_parse_word("name");
			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, var->refname);
			function->tg_relname_varno = var->varno;

			/* ----------
			 * Add the variable tg_nargs
			 * ----------
			 */
			var = malloc(sizeof(PLpgSQL_var));
			memset(var, 0, sizeof(PLpgSQL_var));

			var->dtype = PLPGSQL_DTYPE_VAR;
			var->refname = strdup("tg_nargs");
			var->lineno = 0;
			plpgsql_parse_word("int4");
			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, var->refname);
			function->tg_nargs_varno = var->varno;

			break;

		default:
			elog(ERROR, "unknown function type %u in plpgsql_compile()",
				 functype);
			break;
	}