Patch backed out, and new combined version attached.
---------------------------------------------------------------------------
Tom Lane wrote:
> Neil Conway <neilc@samurai.com> writes:
> > Tom Lane wrote:
> >> Alternatively we could make them local to any block that contains an
> >> EXCEPTION clause, which would fix point 3 and also go a long way towards
> >> addressing the unnecessary-overhead gripe. However that would mean that
> >> an attempt to reference them from outside an exception handler would
> >> probably fail outright, rather than deliver either NULLs or
> >> 00000/"Successful completion".
>
> > This behavior sounds fine to me.
>
> I think the key distinction between this proposal and my other one
> (that SQLSTATE/SQLERRM be procedure-local) is whether you want the error
> status to be available to code that immediately follows the BEGIN block
> containing the exception handler. That is, consider code like
>
> BEGIN
> -- do something perilous
> EXCEPTION
> WHEN OTHERS THEN -- nothing much
> END;
> IF SQLSTATE = '42000' THEN ...
>
> At the moment I don't have a strong opinion about this. It seems
> closely analogous to the question whether a loop iteration variable
> should remain defined after the loop exits --- you can find cases
> where that's handy, but you can also argue it shouldn't be used.
> plpgsql itself is schizophrenic on the point (see integer versus
> record FOR-loops), which means we don't have a solid precedent to go by.
>
> regards, tom lane
>
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--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
Index: doc/src/sgml/plpgsql.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v
retrieving revision 1.69
diff -c -c -r1.69 plpgsql.sgml
*** doc/src/sgml/plpgsql.sgml 26 May 2005 04:08:31 -0000 1.69
--- doc/src/sgml/plpgsql.sgml 26 May 2005 04:09:42 -0000
***************
*** 2007,2018 ****
</indexterm>
<para>
! By default, any error occurring in a <application>PL/pgSQL</>
! function aborts execution of the function, and indeed of the
! surrounding transaction as well. You can trap errors and recover
! from them by using a <command>BEGIN</> block with an
! <literal>EXCEPTION</> clause. The syntax is an extension of the
! normal syntax for a <command>BEGIN</> block:
<synopsis>
<optional> <<<replaceable>label</replaceable>>> </optional>
--- 2007,2019 ----
</indexterm>
<para>
! Any error occurring in <application>PL/pgSQL</> sets variables
! <varname>SQLSTATE</> and <varname>SQLERRM</>, and, by default,
! aborts execution of the function, and indeed of the surrounding
! transaction as well. You can trap errors and recover from them by
! using a <command>BEGIN</> block with an <literal>EXCEPTION</>
! clause. The syntax is an extension of the normal syntax for a
! <command>BEGIN</> block:
<synopsis>
<optional> <<<replaceable>label</replaceable>>> </optional>
Index: src/pl/plpgsql/src/gram.y
===================================================================
RCS file: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v
retrieving revision 1.72
diff -c -c -r1.72 gram.y
*** src/pl/plpgsql/src/gram.y 26 May 2005 04:08:31 -0000 1.72
--- src/pl/plpgsql/src/gram.y 26 May 2005 04:09:44 -0000
***************
*** 80,85 ****
--- 80,90 ----
int n_initvars;
int *initvarnos;
} declhdr;
+ struct
+ {
+ int sqlstate_varno;
+ int sqlerrm_varno;
+ } fict_vars;
List *list;
PLpgSQL_type *dtype;
PLpgSQL_datum *scalar; /* a VAR, RECFIELD, or TRIGARG */
***************
*** 96,101 ****
--- 101,107 ----
PLpgSQL_diag_item *diagitem;
}
+ %type <fict_vars> fict_vars_sect
%type <declhdr> decl_sect
%type <varname> decl_varname
%type <str> decl_renname
***************
*** 244,262 ****
| ';'
;
! pl_block : decl_sect K_BEGIN lno proc_sect exception_sect K_END
{
PLpgSQL_stmt_block *new;
new = palloc0(sizeof(PLpgSQL_stmt_block));
new->cmd_type = PLPGSQL_STMT_BLOCK;
! new->lineno = $3;
new->label = $1.label;
new->n_initvars = $1.n_initvars;
new->initvarnos = $1.initvarnos;
! new->body = $4;
! new->exceptions = $5;
plpgsql_ns_pop();
--- 250,271 ----
| ';'
;
! pl_block : decl_sect fict_vars_sect K_BEGIN lno proc_sect exception_sect K_END
{
PLpgSQL_stmt_block *new;
new = palloc0(sizeof(PLpgSQL_stmt_block));
new->cmd_type = PLPGSQL_STMT_BLOCK;
! new->lineno = $4;
new->label = $1.label;
new->n_initvars = $1.n_initvars;
new->initvarnos = $1.initvarnos;
! new->body = $5;
! new->exceptions = $6;
!
! new->sqlstate_varno = $2.sqlstate_varno;
! new->sqlerrm_varno = $2.sqlerrm_varno;
plpgsql_ns_pop();
***************
*** 264,269 ****
--- 273,292 ----
}
;
+ fict_vars_sect :
+ {
+ PLpgSQL_variable *var;
+
+ plpgsql_ns_setlocal(false);
+ var = plpgsql_build_variable("sqlstate", 0,
+ plpgsql_build_datatype(TEXTOID, -1), true);
+ $$.sqlstate_varno = var->dno;
+ var = plpgsql_build_variable("sqlerrm", 0,
+ plpgsql_build_datatype(TEXTOID, -1), true);
+ $$.sqlerrm_varno = var->dno;
+ plpgsql_add_initdatums(NULL);
+ }
+ ;
decl_sect : opt_label
{
Index: src/pl/plpgsql/src/pl_exec.c
===================================================================
RCS file: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v
retrieving revision 1.141
diff -c -c -r1.141 pl_exec.c
*** src/pl/plpgsql/src/pl_exec.c 26 May 2005 04:08:31 -0000 1.141
--- src/pl/plpgsql/src/pl_exec.c 26 May 2005 04:09:46 -0000
***************
*** 180,185 ****
--- 180,186 ----
static void exec_init_tuple_store(PLpgSQL_execstate *estate);
static bool compatible_tupdesc(TupleDesc td1, TupleDesc td2);
static void exec_set_found(PLpgSQL_execstate *estate, bool state);
+ static char *unpack_sql_state(int ssval);
/* ----------
***************
*** 747,752 ****
--- 748,767 ----
int i;
int n;
+
+ /* setup SQLSTATE and SQLERRM */
+ PLpgSQL_var *var;
+
+ var = (PLpgSQL_var *) (estate->datums[block->sqlstate_varno]);
+ var->isnull = false;
+ var->freeval = true;
+ var->value = DirectFunctionCall1(textin, CStringGetDatum("00000"));
+
+ var = (PLpgSQL_var *) (estate->datums[block->sqlerrm_varno]);
+ var->isnull = false;
+ var->freeval = true;
+ var->value = DirectFunctionCall1(textin, CStringGetDatum("Successful completion"));
+
/*
* First initialize all variables declared in this block
*/
***************
*** 762,768 ****
if (var->freeval)
{
! pfree((void *) (var->value));
var->freeval = false;
}
--- 777,783 ----
if (var->freeval)
{
! pfree(DatumGetPointer(var->value));
var->freeval = false;
}
***************
*** 855,860 ****
--- 870,884 ----
RollbackAndReleaseCurrentSubTransaction();
MemoryContextSwitchTo(oldcontext);
CurrentResourceOwner = oldowner;
+
+ /* set SQLSTATE and SQLERRM variables */
+ var = (PLpgSQL_var *) (estate->datums[block->sqlstate_varno]);
+ pfree(DatumGetPointer(var->value));
+ var->value = DirectFunctionCall1(textin, CStringGetDatum(unpack_sql_state(edata->sqlerrcode)));
+
+ var = (PLpgSQL_var *) (estate->datums[block->sqlerrm_varno]);
+ pfree(DatumGetPointer(var->value));
+ var->value = DirectFunctionCall1(textin, CStringGetDatum(edata->message));
/*
* If AtEOSubXact_SPI() popped any SPI context of the subxact,
***************
*** 919,924 ****
--- 943,968 ----
return PLPGSQL_RC_OK;
}
+ /*
+ * unpack MAKE_SQLSTATE code
+ * This code is copied from backend/utils/error/elog.c.
+ */
+ static char *
+ unpack_sql_state(int ssval)
+ {
+ static char tbuf[12];
+ int i;
+
+ for (i = 0; i < 5; i++)
+ {
+ tbuf[i] = PGUNSIXBIT(ssval);
+ ssval >>= 6;
+ }
+ tbuf[i] = '\0';
+ return tbuf;
+ }
+
+
/* ----------
* exec_stmts Iterate over a list of statements
Index: src/pl/plpgsql/src/plpgsql.h
===================================================================
RCS file: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v
retrieving revision 1.60
diff -c -c -r1.60 plpgsql.h
*** src/pl/plpgsql/src/plpgsql.h 26 May 2005 04:08:31 -0000 1.60
--- src/pl/plpgsql/src/plpgsql.h 26 May 2005 04:09:46 -0000
***************
*** 336,344 ****
int lineno;
char *label;
List *body; /* List of statements */
! List *exceptions; /* List of WHEN clauses */
! int n_initvars;
! int *initvarnos;
} PLpgSQL_stmt_block;
--- 336,346 ----
int lineno;
char *label;
List *body; /* List of statements */
! List *exceptions; /* List of WHEN clauses */
! int n_initvars;
! int *initvarnos;
! int sqlstate_varno;
! int sqlerrm_varno;
} PLpgSQL_stmt_block;
Index: src/test/regress/expected/plpgsql.out
===================================================================
RCS file: /cvsroot/pgsql/src/test/regress/expected/plpgsql.out,v
retrieving revision 1.31
diff -c -c -r1.31 plpgsql.out
*** src/test/regress/expected/plpgsql.out 26 May 2005 04:08:31 -0000 1.31
--- src/test/regress/expected/plpgsql.out 26 May 2005 04:09:48 -0000
***************
*** 2380,2382 ****
--- 2380,2408 ----
CONTEXT: PL/pgSQL function "missing_return_expr"
drop function void_return_expr();
drop function missing_return_expr();
+ -- test SQLSTATE and SQLERRM
+ create function trap_exceptions() returns void as $_$
+ begin
+ begin
+ raise exception 'first exception';
+ exception when others then
+ raise notice '% %', SQLSTATE, SQLERRM;
+ end;
+ raise notice '% %', SQLSTATE, SQLERRM;
+ begin
+ raise exception 'last exception';
+ exception when others then
+ raise notice '% %', SQLSTATE, SQLERRM;
+ end;
+ return;
+ end; $_$ language plpgsql;
+ select trap_exceptions();
+ NOTICE: P0001 first exception
+ NOTICE: 00000 Successful completion
+ NOTICE: P0001 last exception
+ trap_exceptions
+ -----------------
+
+ (1 row)
+
+ drop function trap_exceptions();
Index: src/test/regress/sql/plpgsql.sql
===================================================================
RCS file: /cvsroot/pgsql/src/test/regress/sql/plpgsql.sql,v
retrieving revision 1.26
diff -c -c -r1.26 plpgsql.sql
*** src/test/regress/sql/plpgsql.sql 26 May 2005 04:08:32 -0000 1.26
--- src/test/regress/sql/plpgsql.sql 26 May 2005 04:09:49 -0000
***************
*** 2018,2020 ****
--- 2018,2041 ----
drop function void_return_expr();
drop function missing_return_expr();
+
+ -- test SQLSTATE and SQLERRM
+ create function trap_exceptions() returns void as $_$
+ begin
+ begin
+ raise exception 'first exception';
+ exception when others then
+ raise notice '% %', SQLSTATE, SQLERRM;
+ end;
+ raise notice '% %', SQLSTATE, SQLERRM;
+ begin
+ raise exception 'last exception';
+ exception when others then
+ raise notice '% %', SQLSTATE, SQLERRM;
+ end;
+ return;
+ end; $_$ language plpgsql;
+
+ select trap_exceptions();
+
+ drop function trap_exceptions();
