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Add a CONTINUE statement to PL/PgSQL, which can be used to begin the

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next iteration of a loop. Update documentation and add regression tests.
Patch from Pavel Stehule, reviewed by Neil Conway.
This commit is contained in:
Neil Conway
2005-06-22 01:35:03 +00:00
parent 7a28de2052
commit ebcb4c931d
8 changed files with 501 additions and 80 deletions
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33
src/pl/plpgsql/src/gram.y
View File

@@ -4,7 +4,7 @@
* procedural language
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.76 2005/06/14 06:43:14 neilc Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.77 2005/06/22 01:35:02 neilc Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -61,6 +61,7 @@ static void plpgsql_sql_error_callback(void *arg);
%union {
int32 ival;
bool boolean;
char *str;
struct
{
@@ -100,7 +101,7 @@ static void plpgsql_sql_error_callback(void *arg);
%type <declhdr> decl_sect
%type <varname> decl_varname
%type <str> decl_renname
%type <ival> decl_const decl_notnull
%type <boolean> decl_const decl_notnull exit_type
%type <expr> decl_defval decl_cursor_query
%type <dtype> decl_datatype
%type <row> decl_cursor_args
@@ -153,6 +154,7 @@ static void plpgsql_sql_error_callback(void *arg);
%token K_BEGIN
%token K_CLOSE
%token K_CONSTANT
%token K_CONTINUE
%token K_CURSOR
%token K_DEBUG
%token K_DECLARE
@@ -514,9 +516,9 @@ decl_renname : T_WORD
;
decl_const :
{ $$ = 0; }
{ $$ = false; }
| K_CONSTANT
{ $$ = 1; }
{ $$ = true; }
;
decl_datatype :
@@ -531,9 +533,9 @@ decl_datatype :
;
decl_notnull :
{ $$ = 0; }
{ $$ = false; }
| K_NOT K_NULL
{ $$ = 1; }
{ $$ = true; }
;
decl_defval : ';'
@@ -1035,13 +1037,14 @@ stmt_select : K_SELECT lno
}
;
stmt_exit : K_EXIT lno opt_exitlabel opt_exitcond
stmt_exit : exit_type lno opt_exitlabel opt_exitcond
{
PLpgSQL_stmt_exit *new;
new = palloc0(sizeof(PLpgSQL_stmt_exit));
new->cmd_type = PLPGSQL_STMT_EXIT;
new->lineno = $2;
new->is_exit = $1;
new->lineno = $2;
new->label = $3;
new->cond = $4;
@@ -1049,6 +1052,16 @@ stmt_exit : K_EXIT lno opt_exitlabel opt_exitcond
}
;
exit_type : K_EXIT
{
$$ = true;
}
| K_CONTINUE
{
$$ = false;
}
;
stmt_return : K_RETURN lno
{
PLpgSQL_stmt_return *new;
@@ -1056,8 +1069,8 @@ stmt_return : K_RETURN lno
new = palloc0(sizeof(PLpgSQL_stmt_return));
new->cmd_type = PLPGSQL_STMT_RETURN;
new->lineno = $2;
new->expr = NULL;
new->retvarno = -1;
new->expr = NULL;
new->retvarno = -1;
if (plpgsql_curr_compile->fn_retset)
{

204
src/pl/plpgsql/src/pl_exec.c
View File

@@ -3,7 +3,7 @@
* procedural language
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.146 2005/06/20 22:51:29 tgl Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.147 2005/06/22 01:35:02 neilc Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -194,6 +194,7 @@ plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo)
PLpgSQL_execstate estate;
ErrorContextCallback plerrcontext;
int i;
int rc;
/*
* Setup the execution state
@@ -282,13 +283,24 @@ plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo)
*/
estate.err_text = NULL;
estate.err_stmt = (PLpgSQL_stmt *) (func->action);
if (exec_stmt_block(&estate, func->action) != PLPGSQL_RC_RETURN)
rc = exec_stmt_block(&estate, func->action);
if (rc != PLPGSQL_RC_RETURN)
{
estate.err_stmt = NULL;
estate.err_text = NULL;
ereport(ERROR,
(errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
errmsg("control reached end of function without RETURN")));
/*
* Provide a more helpful message if a CONTINUE has been used
* outside a loop.
*/
if (rc == PLPGSQL_RC_CONTINUE)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("CONTINUE cannot be used outside a loop")));
else
ereport(ERROR,
(errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
errmsg("control reached end of function without RETURN")));
}
/*
@@ -393,6 +405,7 @@ plpgsql_exec_trigger(PLpgSQL_function *func,
PLpgSQL_execstate estate;
ErrorContextCallback plerrcontext;
int i;
int rc;
PLpgSQL_var *var;
PLpgSQL_rec *rec_new,
*rec_old;
@@ -546,13 +559,24 @@ plpgsql_exec_trigger(PLpgSQL_function *func,
*/
estate.err_text = NULL;
estate.err_stmt = (PLpgSQL_stmt *) (func->action);
if (exec_stmt_block(&estate, func->action) != PLPGSQL_RC_RETURN)
rc = exec_stmt_block(&estate, func->action);
if (rc != PLPGSQL_RC_RETURN)
{
estate.err_stmt = NULL;
estate.err_text = NULL;
ereport(ERROR,
(errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
errmsg("control reached end of trigger procedure without RETURN")));
/*
* Provide a more helpful message if a CONTINUE has been used
* outside a loop.
*/
if (rc == PLPGSQL_RC_CONTINUE)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("CONTINUE cannot be used outside a loop")));
else
ereport(ERROR,
(errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
errmsg("control reached end of trigger procedure without RETURN")));
}
if (estate.retisset)
@@ -919,7 +943,9 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
switch (rc)
{
case PLPGSQL_RC_OK:
return PLPGSQL_RC_OK;
case PLPGSQL_RC_CONTINUE:
case PLPGSQL_RC_RETURN:
return rc;
case PLPGSQL_RC_EXIT:
if (estate->exitlabel == NULL)
@@ -930,10 +956,7 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
return PLPGSQL_RC_EXIT;
estate->exitlabel = NULL;
return PLPGSQL_RC_OK;
case PLPGSQL_RC_RETURN:
return PLPGSQL_RC_RETURN;
default:
elog(ERROR, "unrecognized rc: %d", rc);
}
@@ -1120,7 +1143,7 @@ exec_stmt_getdiag(PLpgSQL_execstate *estate, PLpgSQL_stmt_getdiag *stmt)
{
PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc);
PLpgSQL_datum *var;
bool isnull = false;
bool isnull;
if (diag_item->target <= 0)
continue;
@@ -1165,7 +1188,7 @@ static int
exec_stmt_if(PLpgSQL_execstate *estate, PLpgSQL_stmt_if *stmt)
{
bool value;
bool isnull = false;
bool isnull;
value = exec_eval_boolean(estate, stmt->cond, &isnull);
exec_eval_cleanup(estate);
@@ -1209,10 +1232,23 @@ exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt)
return PLPGSQL_RC_OK;
if (stmt->label == NULL)
return PLPGSQL_RC_EXIT;
if (strcmp(stmt->label, estate->exitlabel))
if (strcmp(stmt->label, estate->exitlabel) != 0)
return PLPGSQL_RC_EXIT;
estate->exitlabel = NULL;
return PLPGSQL_RC_OK;
case PLPGSQL_RC_CONTINUE:
if (estate->exitlabel == NULL)
/* anonymous continue, so re-run the loop */
break;
else if (stmt->label != NULL &&
strcmp(stmt->label, estate->exitlabel) == 0)
/* label matches named continue, so re-run loop */
estate->exitlabel = NULL;
else
/* label doesn't match named continue, so propagate upward */
return PLPGSQL_RC_CONTINUE;
break;
case PLPGSQL_RC_RETURN:
return PLPGSQL_RC_RETURN;
@@ -1236,7 +1272,7 @@ static int
exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt)
{
bool value;
bool isnull = false;
bool isnull;
int rc;
for (;;)
@@ -1264,6 +1300,19 @@ exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt)
estate->exitlabel = NULL;
return PLPGSQL_RC_OK;
case PLPGSQL_RC_CONTINUE:
if (estate->exitlabel == NULL)
/* anonymous continue, so re-run loop */
break;
else if (stmt->label != NULL &&
strcmp(stmt->label, estate->exitlabel) == 0)
/* label matches named continue, so re-run loop */
estate->exitlabel = NULL;
else
/* label doesn't match named continue, propagate upward */
return PLPGSQL_RC_CONTINUE;
break;
case PLPGSQL_RC_RETURN:
return PLPGSQL_RC_RETURN;
@@ -1288,7 +1337,7 @@ exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt)
PLpgSQL_var *var;
Datum value;
Oid valtype;
bool isnull = false;
bool isnull;
bool found = false;
int rc = PLPGSQL_RC_OK;
@@ -1366,13 +1415,35 @@ exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt)
}
/*
* otherwise, we processed a labelled exit that does not match
* the current statement's label, if any: return RC_EXIT so
* that the EXIT continues to recurse upward.
* otherwise, this is a labelled exit that does not match
* the current statement's label, if any: return RC_EXIT
* so that the EXIT continues to propagate up the stack.
*/
break;
}
else if (rc == PLPGSQL_RC_CONTINUE)
{
if (estate->exitlabel == NULL)
/* anonymous continue, so continue the current loop */
;
else if (stmt->label != NULL &&
strcmp(stmt->label, estate->exitlabel) == 0)
{
/* labelled continue, matches the current stmt's label */
estate->exitlabel = NULL;
}
else
{
/*
* otherwise, this is a labelled continue that does
* not match the current statement's label, if any:
* return RC_CONTINUE so that the CONTINUE will
* propagate up the stack.
*/
break;
}
}
/*
* Increase/decrease loop var
@@ -1459,17 +1530,8 @@ exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt)
* Execute the statements
*/
rc = exec_stmts(estate, stmt->body);
if (rc != PLPGSQL_RC_OK)
{
/*
* We're aborting the loop, so cleanup and set FOUND.
* (This code should match the code after the loop.)
*/
SPI_freetuptable(tuptab);
SPI_cursor_close(portal);
exec_set_found(estate, found);
if (rc == PLPGSQL_RC_EXIT)
{
if (estate->exitlabel == NULL)
@@ -1490,6 +1552,34 @@ exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt)
* recurse upward.
*/
}
else if (rc == PLPGSQL_RC_CONTINUE)
{
if (estate->exitlabel == NULL)
/* unlabelled continue, continue the current loop */
continue;
else if (stmt->label != NULL &&
strcmp(stmt->label, estate->exitlabel) == 0)
{
/* labelled continue, matches the current stmt's label */
estate->exitlabel = NULL;
continue;
}
/*
* otherwise, we processed a labelled continue
* that does not match the current statement's
* label, if any: return RC_CONTINUE so that the
* CONTINUE will propagate up the stack.
*/
}
/*
* We're aborting the loop, so cleanup and set FOUND.
* (This code should match the code after the loop.)
*/
SPI_freetuptable(tuptab);
SPI_cursor_close(portal);
exec_set_found(estate, found);
return rc;
}
@@ -1563,7 +1653,7 @@ exec_stmt_select(PLpgSQL_execstate *estate, PLpgSQL_stmt_select *stmt)
n = estate->eval_processed;
/*
* If the query didn't return any row, set the target to NULL and
* If the query didn't return any rows, set the target to NULL and
* return.
*/
if (n == 0)
@@ -1586,28 +1676,33 @@ exec_stmt_select(PLpgSQL_execstate *estate, PLpgSQL_stmt_select *stmt)
/* ----------
* exec_stmt_exit Start exiting loop(s) or blocks
* exec_stmt_exit Implements EXIT and CONTINUE
*
* This begins the process of exiting / restarting a loop.
* ----------
*/
static int
exec_stmt_exit(PLpgSQL_execstate *estate, PLpgSQL_stmt_exit *stmt)
{
/*
* If the exit has a condition, check that it's true
* If the exit / continue has a condition, evaluate it
*/
if (stmt->cond != NULL)
{
bool value;
bool isnull = false;
bool isnull;
value = exec_eval_boolean(estate, stmt->cond, &isnull);
exec_eval_cleanup(estate);
if (isnull || !value)
if (isnull || value == false)
return PLPGSQL_RC_OK;
}
estate->exitlabel = stmt->label;
return PLPGSQL_RC_EXIT;
if (stmt->is_exit)
return PLPGSQL_RC_EXIT;
else
return PLPGSQL_RC_CONTINUE;
}
@@ -2455,14 +2550,6 @@ exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt)
if (rc != PLPGSQL_RC_OK)
{
/*
* We're aborting the loop, so cleanup and set FOUND.
* (This code should match the code after the loop.)
*/
SPI_freetuptable(tuptab);
SPI_cursor_close(portal);
exec_set_found(estate, found);
if (rc == PLPGSQL_RC_EXIT)
{
if (estate->exitlabel == NULL)
@@ -2483,6 +2570,33 @@ exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt)
* recurse upward.
*/
}
else if (rc == PLPGSQL_RC_CONTINUE)
{
if (estate->exitlabel == NULL)
/* unlabelled continue, continue the current loop */
continue;
else if (stmt->label != NULL &&
strcmp(stmt->label, estate->exitlabel) == 0)
{
/* labelled continue, matches the current stmt's label */
estate->exitlabel = NULL;
continue;
}
/*
* otherwise, we process a labelled continue that
* does not match the current statement's label,
* so propagate RC_CONTINUE upward in the stack.
*/
}
/*
* We're aborting the loop, so cleanup and set FOUND.
* (This code should match the code after the loop.)
*/
SPI_freetuptable(tuptab);
SPI_cursor_close(portal);
exec_set_found(estate, found);
return rc;
}

5
src/pl/plpgsql/src/pl_funcs.c
View File

@@ -3,7 +3,7 @@
* procedural language
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.44 2005/06/19 01:06:12 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.45 2005/06/22 01:35:02 neilc Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -845,7 +845,8 @@ static void
dump_exit(PLpgSQL_stmt_exit *stmt)
{
dump_ind();
printf("EXIT lbl='%s'", stmt->label);
printf("%s label='%s'",
stmt->is_exit ? "EXIT" : "CONTINUE", stmt->label);
if (stmt->cond != NULL)
{
printf(" WHEN ");

11
src/pl/plpgsql/src/plpgsql.h
View File

@@ -3,7 +3,7 @@
* procedural language
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.63 2005/06/14 06:43:14 neilc Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.64 2005/06/22 01:35:02 neilc Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -125,7 +125,8 @@ enum
{
PLPGSQL_RC_OK,
PLPGSQL_RC_EXIT,
PLPGSQL_RC_RETURN
PLPGSQL_RC_RETURN,
PLPGSQL_RC_CONTINUE
};
/* ----------
@@ -485,9 +486,10 @@ typedef struct
typedef struct
{ /* EXIT statement */
{ /* EXIT or CONTINUE statement */
int cmd_type;
int lineno;
bool is_exit; /* Is this an exit or a continue? */
char *label;
PLpgSQL_expr *cond;
} PLpgSQL_stmt_exit;
@@ -610,7 +612,8 @@ typedef struct
bool readonly_func;
TupleDesc rettupdesc;
char *exitlabel;
char *exitlabel; /* the "target" label of the current
* EXIT or CONTINUE stmt, if any */
Tuplestorestate *tuple_store; /* SRFs accumulate results here */
MemoryContext tuple_store_cxt;

3
src/pl/plpgsql/src/scan.l
View File

@@ -4,7 +4,7 @@
* procedural language
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.40 2005/03/11 19:13:43 momjian Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.41 2005/06/22 01:35:02 neilc Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -139,6 +139,7 @@ alias { return K_ALIAS; }
begin { return K_BEGIN; }
close { return K_CLOSE; }
constant { return K_CONSTANT; }
continue { return K_CONTINUE; }
cursor { return K_CURSOR; }
debug { return K_DEBUG; }
declare { return K_DECLARE; }