From a4482f4c4c4e052f954f4f333ae8f5ce999613ab Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 21 Jan 2003 22:06:12 +0000 Subject: [PATCH] Fix coredump problem in plpgsql's RETURN NEXT. When a SELECT INTO that's selecting into a RECORD variable returns zero rows, make it assign an all-nulls row to the RECORD; this is consistent with what happens when the SELECT INTO target is not a RECORD. In support of this, tweak the SPI code so that a valid tuple descriptor is returned even when a SPI select returns no rows. --- doc/src/sgml/spi.sgml | 6 +- src/backend/executor/spi.c | 102 +++++++++++++++++++--------------- src/backend/tcop/dest.c | 4 +- src/include/access/printtup.h | 6 +- src/pl/plpgsql/src/pl_exec.c | 52 ++++++++++++----- 5 files changed, 106 insertions(+), 64 deletions(-) diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml index 403baea4e3..b3c65204c4 100644 --- a/doc/src/sgml/spi.sgml +++ b/doc/src/sgml/spi.sgml @@ -1,5 +1,5 @@ @@ -476,7 +476,7 @@ You may pass multiple queries in one string or query string may be The actual number of tuples for which the (last) query was executed is returned in the global variable SPI_processed (if not SPI_OK_UTILITY). - If SPI_OK_SELECT is returned and SPI_processed > 0 then you may use global + If SPI_OK_SELECT is returned then you may use global pointer SPITupleTable *SPI_tuptable to access the result tuples. @@ -517,7 +517,7 @@ You may pass multiple queries in one string or query string may be Structures - If SPI_OK_SELECT is returned and SPI_processed > 0 then you may use the global + If SPI_OK_SELECT is returned then you may use the global pointer SPITupleTable *SPI_tuptable to access the selected tuples. diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c index abca504f2a..3df2426473 100644 --- a/src/backend/executor/spi.c +++ b/src/backend/executor/spi.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.83 2002/12/30 22:10:54 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.84 2003/01/21 22:06:12 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -874,18 +874,60 @@ SPI_cursor_close(Portal portal) /* =================== private functions =================== */ /* - * spi_printtup - * store tuple retrieved by Executor into SPITupleTable + * spi_dest_setup + * Initialize to receive tuples from Executor into SPITupleTable * of current SPI procedure - * */ void -spi_printtup(HeapTuple tuple, TupleDesc tupdesc, DestReceiver *self) +spi_dest_setup(DestReceiver *self, int operation, + const char *portalName, TupleDesc typeinfo) { SPITupleTable *tuptable; MemoryContext oldcxt; MemoryContext tuptabcxt; + /* + * When called by Executor _SPI_curid expected to be equal to + * _SPI_connected + */ + if (_SPI_curid != _SPI_connected || _SPI_connected < 0) + elog(FATAL, "SPI: improper call to spi_dest_setup"); + if (_SPI_current != &(_SPI_stack[_SPI_curid])) + elog(FATAL, "SPI: stack corrupted in spi_dest_setup"); + + if (_SPI_current->tuptable != NULL) + elog(FATAL, "SPI: improper call to spi_dest_setup"); + + oldcxt = _SPI_procmem(); /* switch to procedure memory context */ + + tuptabcxt = AllocSetContextCreate(CurrentMemoryContext, + "SPI TupTable", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + MemoryContextSwitchTo(tuptabcxt); + + _SPI_current->tuptable = tuptable = (SPITupleTable *) + palloc(sizeof(SPITupleTable)); + tuptable->tuptabcxt = tuptabcxt; + tuptable->alloced = tuptable->free = 128; + tuptable->vals = (HeapTuple *) palloc(tuptable->alloced * sizeof(HeapTuple)); + tuptable->tupdesc = CreateTupleDescCopy(typeinfo); + + MemoryContextSwitchTo(oldcxt); +} + +/* + * spi_printtup + * store tuple retrieved by Executor into SPITupleTable + * of current SPI procedure + */ +void +spi_printtup(HeapTuple tuple, TupleDesc tupdesc, DestReceiver *self) +{ + SPITupleTable *tuptable; + MemoryContext oldcxt; + /* * When called by Executor _SPI_curid expected to be equal to * _SPI_connected @@ -895,43 +937,24 @@ spi_printtup(HeapTuple tuple, TupleDesc tupdesc, DestReceiver *self) if (_SPI_current != &(_SPI_stack[_SPI_curid])) elog(FATAL, "SPI: stack corrupted in spi_printtup"); - oldcxt = _SPI_procmem(); /* switch to procedure memory context */ - tuptable = _SPI_current->tuptable; if (tuptable == NULL) - { - tuptabcxt = AllocSetContextCreate(CurrentMemoryContext, - "SPI TupTable", - ALLOCSET_DEFAULT_MINSIZE, - ALLOCSET_DEFAULT_INITSIZE, - ALLOCSET_DEFAULT_MAXSIZE); - MemoryContextSwitchTo(tuptabcxt); + elog(FATAL, "SPI: improper call to spi_printtup"); - _SPI_current->tuptable = tuptable = (SPITupleTable *) - palloc(sizeof(SPITupleTable)); - tuptable->tuptabcxt = tuptabcxt; - tuptable->alloced = tuptable->free = 128; - tuptable->vals = (HeapTuple *) palloc(tuptable->alloced * sizeof(HeapTuple)); - tuptable->tupdesc = CreateTupleDescCopy(tupdesc); - } - else - { - MemoryContextSwitchTo(tuptable->tuptabcxt); + oldcxt = MemoryContextSwitchTo(tuptable->tuptabcxt); - if (tuptable->free == 0) - { - tuptable->free = 256; - tuptable->alloced += tuptable->free; - tuptable->vals = (HeapTuple *) repalloc(tuptable->vals, + if (tuptable->free == 0) + { + tuptable->free = 256; + tuptable->alloced += tuptable->free; + tuptable->vals = (HeapTuple *) repalloc(tuptable->vals, tuptable->alloced * sizeof(HeapTuple)); - } } tuptable->vals[tuptable->alloced - tuptable->free] = heap_copytuple(tuple); (tuptable->free)--; MemoryContextSwitchTo(oldcxt); - return; } /* @@ -1448,19 +1471,10 @@ _SPI_checktuples(void) SPITupleTable *tuptable = _SPI_current->tuptable; bool failed = false; - if (processed == 0) - { - if (tuptable != NULL) - failed = true; - } - else - { - /* some tuples were processed */ - if (tuptable == NULL) /* spi_printtup was not called */ - failed = true; - else if (processed != (tuptable->alloced - tuptable->free)) - failed = true; - } + if (tuptable == NULL) /* spi_dest_setup was not called */ + failed = true; + else if (processed != (tuptable->alloced - tuptable->free)) + failed = true; return failed; } diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c index 2face9fc10..516af21a46 100644 --- a/src/backend/tcop/dest.c +++ b/src/backend/tcop/dest.c @@ -8,7 +8,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/tcop/dest.c,v 1.49 2002/06/20 20:29:36 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/tcop/dest.c,v 1.50 2003/01/21 22:06:12 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -64,7 +64,7 @@ static DestReceiver debugtupDR = { debugtup, debugSetup, donothingCleanup }; static DestReceiver spi_printtupDR = { - spi_printtup, donothingSetup, donothingCleanup + spi_printtup, spi_dest_setup, donothingCleanup }; /* ---------------- diff --git a/src/include/access/printtup.h b/src/include/access/printtup.h index e8c4fa352f..728b0c8990 100644 --- a/src/include/access/printtup.h +++ b/src/include/access/printtup.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: printtup.h,v 1.22 2002/09/04 20:31:37 momjian Exp $ + * $Id: printtup.h,v 1.23 2003/01/21 22:06:12 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -23,7 +23,9 @@ extern void debugSetup(DestReceiver *self, int operation, extern void debugtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self); -/* XXX this one is really in executor/spi.c */ +/* XXX these are really in executor/spi.c */ +extern void spi_dest_setup(DestReceiver *self, int operation, + const char *portalName, TupleDesc typeinfo); extern void spi_printtup(HeapTuple tuple, TupleDesc tupdesc, DestReceiver *self); diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c index 8e0e1ffda3..c9fd9418b4 100644 --- a/src/pl/plpgsql/src/pl_exec.c +++ b/src/pl/plpgsql/src/pl_exec.c @@ -3,7 +3,7 @@ * procedural language * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.76 2002/12/17 15:45:01 tgl Exp $ + * $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.77 2003/01/21 22:06:12 tgl Exp $ * * This software is copyrighted by Jan Wieck - Hamburg. * @@ -1356,15 +1356,15 @@ exec_stmt_fors(PLpgSQL_execstate * estate, PLpgSQL_stmt_fors * stmt) exec_run_select(estate, stmt->query, 0, &portal); SPI_cursor_fetch(portal, true, 10); - n = SPI_processed; tuptab = SPI_tuptable; + n = SPI_processed; /* * If the query didn't return any rows, set the target to NULL and * return with FOUND = false. */ if (n == 0) - exec_move_row(estate, rec, row, NULL, NULL); + exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); else found = true; /* processed at least one tuple */ @@ -1478,6 +1478,7 @@ exec_stmt_select(PLpgSQL_execstate * estate, PLpgSQL_stmt_select * stmt) * Run the query */ exec_run_select(estate, stmt->query, 1, NULL); + tuptab = estate->eval_tuptable; n = estate->eval_processed; /* @@ -1486,7 +1487,7 @@ exec_stmt_select(PLpgSQL_execstate * estate, PLpgSQL_stmt_select * stmt) */ if (n == 0) { - exec_move_row(estate, rec, row, NULL, NULL); + exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); exec_eval_cleanup(estate); return PLPGSQL_RC_OK; } @@ -1494,7 +1495,6 @@ exec_stmt_select(PLpgSQL_execstate * estate, PLpgSQL_stmt_select * stmt) /* * Put the result into the target and set found to true */ - tuptab = estate->eval_tuptable; exec_move_row(estate, rec, row, tuptab->vals[0], tuptab->tupdesc); exec_set_found(estate, true); @@ -1627,6 +1627,8 @@ exec_stmt_return_next(PLpgSQL_execstate * estate, { PLpgSQL_rec *rec = (PLpgSQL_rec *) (estate->datums[stmt->rec->recno]); + if (!HeapTupleIsValid(rec->tup)) + elog(ERROR, "record \"%s\" is unassigned yet", rec->refname); if (!compatible_tupdesc(tupdesc, rec->tupdesc)) elog(ERROR, "Wrong record type supplied in RETURN NEXT"); tuple = rec->tup; @@ -2369,15 +2371,15 @@ exec_stmt_dynfors(PLpgSQL_execstate * estate, PLpgSQL_stmt_dynfors * stmt) * Fetch the initial 10 tuples */ SPI_cursor_fetch(portal, true, 10); - n = SPI_processed; tuptab = SPI_tuptable; + n = SPI_processed; /* * If the query didn't return any rows, set the target to NULL and * return with FOUND = false. */ if (n == 0) - exec_move_row(estate, rec, row, NULL, NULL); + exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); else found = true; @@ -2776,8 +2778,8 @@ exec_stmt_fetch(PLpgSQL_execstate * estate, PLpgSQL_stmt_fetch * stmt) * ---------- */ SPI_cursor_fetch(portal, true, 1); - n = SPI_processed; tuptab = SPI_tuptable; + n = SPI_processed; /* ---------- * If the FETCH didn't return a row, set the target @@ -2786,7 +2788,7 @@ exec_stmt_fetch(PLpgSQL_execstate * estate, PLpgSQL_stmt_fetch * stmt) */ if (n == 0) { - exec_move_row(estate, rec, row, NULL, NULL); + exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); return PLPGSQL_RC_OK; } @@ -3353,8 +3355,8 @@ exec_move_row(PLpgSQL_execstate * estate, HeapTuple tup, TupleDesc tupdesc) { /* - * Record is simple - just put the tuple and its descriptor into the - * record + * Record is simple - just copy the tuple and its descriptor into the + * record variable */ if (rec != NULL) { @@ -3372,13 +3374,34 @@ exec_move_row(PLpgSQL_execstate * estate, if (HeapTupleIsValid(tup)) { rec->tup = heap_copytuple(tup); - rec->tupdesc = CreateTupleDescCopy(tupdesc); rec->freetup = true; - rec->freetupdesc = true; + } + else if (tupdesc) + { + /* If we have a tupdesc but no data, form an all-nulls tuple */ + char *nulls; + + /* +1 to avoid possible palloc(0) if no attributes */ + nulls = (char *) palloc(tupdesc->natts * sizeof(char) + 1); + memset(nulls, 'n', tupdesc->natts * sizeof(char)); + + rec->tup = heap_formtuple(tupdesc, NULL, nulls); + rec->freetup = true; + + pfree(nulls); } else { rec->tup = NULL; + } + + if (tupdesc) + { + rec->tupdesc = CreateTupleDescCopy(tupdesc); + rec->freetupdesc = true; + } + else + { rec->tupdesc = NULL; } @@ -3395,6 +3418,9 @@ exec_move_row(PLpgSQL_execstate * estate, * table, or it might have fewer if the table has had columns added by * ALTER TABLE. Ignore extra columns and assume NULL for missing * columns, the same as heap_getattr would do. + * + * If we have no tuple data at all, we'll assign NULL to all columns + * of the row variable. */ if (row != NULL) {