/*------------------------------------------------------------------------- * * pl_exec.c - Executor for the PL/pgSQL * procedural language * * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.252 2009/12/29 17:40:59 heikki Exp $ * *------------------------------------------------------------------------- */ #include "plpgsql.h" #include #include "access/transam.h" #include "access/tupconvert.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" #include "executor/spi_priv.h" #include "funcapi.h" #include "miscadmin.h" #include "nodes/nodeFuncs.h" #include "parser/scansup.h" #include "storage/proc.h" #include "tcop/tcopprot.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/datum.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/snapmgr.h" #include "utils/typcache.h" static const char *const raise_skip_msg = "RAISE"; typedef struct { int nargs; /* number of arguments */ Oid *types; /* types of arguments */ Datum *values; /* evaluated argument values */ char *nulls; /* null markers (' '/'n' style) */ bool *freevals; /* which arguments are pfree-able */ } PreparedParamsData; /* * All plpgsql function executions within a single transaction share the same * executor EState for evaluating "simple" expressions. Each function call * creates its own "eval_econtext" ExprContext within this estate for * per-evaluation workspace. eval_econtext is freed at normal function exit, * and the EState is freed at transaction end (in case of error, we assume * that the abort mechanisms clean it all up). Furthermore, any exception * block within a function has to have its own eval_econtext separate from * the containing function's, so that we can clean up ExprContext callbacks * properly at subtransaction exit. We maintain a stack that tracks the * individual econtexts so that we can clean up correctly at subxact exit. * * This arrangement is a bit tedious to maintain, but it's worth the trouble * so that we don't have to re-prepare simple expressions on each trip through * a function. (We assume the case to optimize is many repetitions of a * function within a transaction.) */ typedef struct SimpleEcontextStackEntry { ExprContext *stack_econtext; /* a stacked econtext */ SubTransactionId xact_subxid; /* ID for current subxact */ struct SimpleEcontextStackEntry *next; /* next stack entry up */ } SimpleEcontextStackEntry; static EState *simple_eval_estate = NULL; static SimpleEcontextStackEntry *simple_econtext_stack = NULL; /************************************************************ * Local function forward declarations ************************************************************/ static void plpgsql_exec_error_callback(void *arg); static PLpgSQL_datum *copy_plpgsql_datum(PLpgSQL_datum *datum); static int exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block); static int exec_stmts(PLpgSQL_execstate *estate, List *stmts); static int exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt); static int exec_stmt_assign(PLpgSQL_execstate *estate, PLpgSQL_stmt_assign *stmt); static int exec_stmt_perform(PLpgSQL_execstate *estate, PLpgSQL_stmt_perform *stmt); static int exec_stmt_getdiag(PLpgSQL_execstate *estate, PLpgSQL_stmt_getdiag *stmt); static int exec_stmt_if(PLpgSQL_execstate *estate, PLpgSQL_stmt_if *stmt); static int exec_stmt_case(PLpgSQL_execstate *estate, PLpgSQL_stmt_case *stmt); static int exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt); static int exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt); static int exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt); static int exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt); static int exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt); static int exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt); static int exec_stmt_fetch(PLpgSQL_execstate *estate, PLpgSQL_stmt_fetch *stmt); static int exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt); static int exec_stmt_exit(PLpgSQL_execstate *estate, PLpgSQL_stmt_exit *stmt); static int exec_stmt_return(PLpgSQL_execstate *estate, PLpgSQL_stmt_return *stmt); static int exec_stmt_return_next(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_next *stmt); static int exec_stmt_return_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_query *stmt); static int exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt); static int exec_stmt_execsql(PLpgSQL_execstate *estate, PLpgSQL_stmt_execsql *stmt); static int exec_stmt_dynexecute(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynexecute *stmt); static int exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt); static void plpgsql_estate_setup(PLpgSQL_execstate *estate, PLpgSQL_function *func, ReturnSetInfo *rsi); static void exec_eval_cleanup(PLpgSQL_execstate *estate); static void exec_prepare_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, int cursorOptions); static bool exec_simple_check_node(Node *node); static void exec_simple_check_plan(PLpgSQL_expr *expr); static bool exec_eval_simple_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, Datum *result, bool *isNull, Oid *rettype); static void exec_assign_expr(PLpgSQL_execstate *estate, PLpgSQL_datum *target, PLpgSQL_expr *expr); static void exec_assign_value(PLpgSQL_execstate *estate, PLpgSQL_datum *target, Datum value, Oid valtype, bool *isNull); static void exec_eval_datum(PLpgSQL_execstate *estate, PLpgSQL_datum *datum, Oid *typeid, Datum *value, bool *isnull); static int exec_eval_integer(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull); static bool exec_eval_boolean(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull); static Datum exec_eval_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull, Oid *rettype); static int exec_run_select(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, long maxtuples, Portal *portalP); static int exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt, Portal portal, bool prefetch_ok); static ParamListInfo setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr); static void plpgsql_param_fetch(ParamListInfo params, int paramid); static void exec_move_row(PLpgSQL_execstate *estate, PLpgSQL_rec *rec, PLpgSQL_row *row, HeapTuple tup, TupleDesc tupdesc); static HeapTuple make_tuple_from_row(PLpgSQL_execstate *estate, PLpgSQL_row *row, TupleDesc tupdesc); static char *convert_value_to_string(Datum value, Oid valtype); static Datum exec_cast_value(Datum value, Oid valtype, Oid reqtype, FmgrInfo *reqinput, Oid reqtypioparam, int32 reqtypmod, bool isnull); static Datum exec_simple_cast_value(Datum value, Oid valtype, Oid reqtype, int32 reqtypmod, bool isnull); static void exec_init_tuple_store(PLpgSQL_execstate *estate); static void exec_set_found(PLpgSQL_execstate *estate, bool state); static void plpgsql_create_econtext(PLpgSQL_execstate *estate); static void plpgsql_destroy_econtext(PLpgSQL_execstate *estate); static void free_var(PLpgSQL_var *var); static void assign_text_var(PLpgSQL_var *var, const char *str); static PreparedParamsData *exec_eval_using_params(PLpgSQL_execstate *estate, List *params); static void free_params_data(PreparedParamsData *ppd); static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate, PLpgSQL_expr *query, List *params); /* ---------- * plpgsql_exec_function Called by the call handler for * function execution. * ---------- */ Datum plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo) { PLpgSQL_execstate estate; ErrorContextCallback plerrcontext; int i; int rc; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo); /* * Setup error traceback support for ereport() */ plerrcontext.callback = plpgsql_exec_error_callback; plerrcontext.arg = &estate; plerrcontext.previous = error_context_stack; error_context_stack = &plerrcontext; /* * Make local execution copies of all the datums */ estate.err_text = gettext_noop("during initialization of execution state"); for (i = 0; i < estate.ndatums; i++) estate.datums[i] = copy_plpgsql_datum(func->datums[i]); /* * Store the actual call argument values into the appropriate variables */ estate.err_text = gettext_noop("while storing call arguments into local variables"); for (i = 0; i < func->fn_nargs; i++) { int n = func->fn_argvarnos[i]; switch (estate.datums[n]->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) estate.datums[n]; var->value = fcinfo->arg[i]; var->isnull = fcinfo->argnull[i]; var->freeval = false; } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) estate.datums[n]; if (!fcinfo->argnull[i]) { HeapTupleHeader td; Oid tupType; int32 tupTypmod; TupleDesc tupdesc; HeapTupleData tmptup; td = DatumGetHeapTupleHeader(fcinfo->arg[i]); /* Extract rowtype info and find a tupdesc */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod); /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup.t_self)); tmptup.t_tableOid = InvalidOid; tmptup.t_data = td; exec_move_row(&estate, NULL, row, &tmptup, tupdesc); ReleaseTupleDesc(tupdesc); } else { /* If arg is null, treat it as an empty row */ exec_move_row(&estate, NULL, row, NULL, NULL); } } break; default: elog(ERROR, "unrecognized dtype: %d", func->datums[i]->dtype); } } estate.err_text = gettext_noop("during function entry"); /* * Set the magic variable FOUND to false */ exec_set_found(&estate, false); /* * Let the instrumentation plugin peek at this function */ if (*plugin_ptr && (*plugin_ptr)->func_beg) ((*plugin_ptr)->func_beg) (&estate, func); /* * Now call the toplevel block of statements */ estate.err_text = NULL; estate.err_stmt = (PLpgSQL_stmt *) (func->action); rc = exec_stmt_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_stmt = NULL; estate.err_text = NULL; /* * Provide a more helpful message if a CONTINUE or RAISE has been used * outside the context it can work in. */ if (rc == PLPGSQL_RC_CONTINUE) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("CONTINUE cannot be used outside a loop"))); else if (rc == PLPGSQL_RC_RERAISE) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE without parameters cannot be used outside an exception handler"))); else ereport(ERROR, (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT), errmsg("control reached end of function without RETURN"))); } /* * We got a return value - process it */ estate.err_stmt = NULL; estate.err_text = gettext_noop("while casting return value to function's return type"); fcinfo->isnull = estate.retisnull; if (estate.retisset) { ReturnSetInfo *rsi = estate.rsi; /* Check caller can handle a set result */ if (!rsi || !IsA(rsi, ReturnSetInfo) || (rsi->allowedModes & SFRM_Materialize) == 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); rsi->returnMode = SFRM_Materialize; /* If we produced any tuples, send back the result */ if (estate.tuple_store) { rsi->setResult = estate.tuple_store; if (estate.rettupdesc) { MemoryContext oldcxt; oldcxt = MemoryContextSwitchTo(estate.tuple_store_cxt); rsi->setDesc = CreateTupleDescCopy(estate.rettupdesc); MemoryContextSwitchTo(oldcxt); } } estate.retval = (Datum) 0; fcinfo->isnull = true; } else if (!estate.retisnull) { if (estate.retistuple) { /* * We have to check that the returned tuple actually matches the * expected result type. XXX would be better to cache the tupdesc * instead of repeating get_call_result_type() */ HeapTuple rettup = (HeapTuple) DatumGetPointer(estate.retval); TupleDesc tupdesc; TupleConversionMap *tupmap; switch (get_call_result_type(fcinfo, NULL, &tupdesc)) { case TYPEFUNC_COMPOSITE: /* got the expected result rowtype, now check it */ tupmap = convert_tuples_by_position(estate.rettupdesc, tupdesc, gettext_noop("returned record type does not match expected record type")); /* it might need conversion */ if (tupmap) rettup = do_convert_tuple(rettup, tupmap); /* no need to free map, we're about to return anyway */ break; case TYPEFUNC_RECORD: /* * Failed to determine actual type of RECORD. We could * raise an error here, but what this means in practice is * that the caller is expecting any old generic rowtype, * so we don't really need to be restrictive. Pass back * the generated result type, instead. */ tupdesc = estate.rettupdesc; if (tupdesc == NULL) /* shouldn't happen */ elog(ERROR, "return type must be a row type"); break; default: /* shouldn't get here if retistuple is true ... */ elog(ERROR, "return type must be a row type"); break; } /* * Copy tuple to upper executor memory, as a tuple Datum. Make * sure it is labeled with the caller-supplied tuple type. */ estate.retval = PointerGetDatum(SPI_returntuple(rettup, tupdesc)); } else { /* Cast value to proper type */ estate.retval = exec_cast_value(estate.retval, estate.rettype, func->fn_rettype, &(func->fn_retinput), func->fn_rettypioparam, -1, fcinfo->isnull); /* * If the function's return type isn't by value, copy the value * into upper executor memory context. */ if (!fcinfo->isnull && !func->fn_retbyval) { Size len; void *tmp; len = datumGetSize(estate.retval, false, func->fn_rettyplen); tmp = SPI_palloc(len); memcpy(tmp, DatumGetPointer(estate.retval), len); estate.retval = PointerGetDatum(tmp); } } } estate.err_text = gettext_noop("during function exit"); /* * Let the instrumentation plugin peek at this function */ if (*plugin_ptr && (*plugin_ptr)->func_end) ((*plugin_ptr)->func_end) (&estate, func); /* Clean up any leftover temporary memory */ plpgsql_destroy_econtext(&estate); exec_eval_cleanup(&estate); /* * Pop the error context stack */ error_context_stack = plerrcontext.previous; /* * Return the function's result */ return estate.retval; } /* ---------- * plpgsql_exec_trigger Called by the call handler for * trigger execution. * ---------- */ HeapTuple plpgsql_exec_trigger(PLpgSQL_function *func, TriggerData *trigdata) { PLpgSQL_execstate estate; ErrorContextCallback plerrcontext; int i; int rc; PLpgSQL_var *var; PLpgSQL_rec *rec_new, *rec_old; HeapTuple rettup; /* * Setup the execution state */ plpgsql_estate_setup(&estate, func, NULL); /* * Setup error traceback support for ereport() */ plerrcontext.callback = plpgsql_exec_error_callback; plerrcontext.arg = &estate; plerrcontext.previous = error_context_stack; error_context_stack = &plerrcontext; /* * Make local execution copies of all the datums */ estate.err_text = gettext_noop("during initialization of execution state"); for (i = 0; i < estate.ndatums; i++) estate.datums[i] = copy_plpgsql_datum(func->datums[i]); /* * Put the OLD and NEW tuples into record variables * * We make the tupdescs available in both records even though only one * may have a value. This allows parsing of record references to succeed * in functions that are used for multiple trigger types. For example, * we might have a test like "if (TG_OP = 'INSERT' and NEW.foo = 'xyz')", * which should parse regardless of the current trigger type. */ rec_new = (PLpgSQL_rec *) (estate.datums[func->new_varno]); rec_new->freetup = false; rec_new->tupdesc = trigdata->tg_relation->rd_att; rec_new->freetupdesc = false; rec_old = (PLpgSQL_rec *) (estate.datums[func->old_varno]); rec_old->freetup = false; rec_old->tupdesc = trigdata->tg_relation->rd_att; rec_old->freetupdesc = false; if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event)) { /* * Per-statement triggers don't use OLD/NEW variables */ rec_new->tup = NULL; rec_old->tup = NULL; } else if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) { rec_new->tup = trigdata->tg_trigtuple; rec_old->tup = NULL; } else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) { rec_new->tup = trigdata->tg_newtuple; rec_old->tup = trigdata->tg_trigtuple; } else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event)) { rec_new->tup = NULL; rec_old->tup = trigdata->tg_trigtuple; } else elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, or UPDATE"); /* * Assign the special tg_ variables */ var = (PLpgSQL_var *) (estate.datums[func->tg_op_varno]); if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) var->value = CStringGetTextDatum("INSERT"); else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) var->value = CStringGetTextDatum("UPDATE"); else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event)) var->value = CStringGetTextDatum("DELETE"); else if (TRIGGER_FIRED_BY_TRUNCATE(trigdata->tg_event)) var->value = CStringGetTextDatum("TRUNCATE"); else elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, UPDATE, or TRUNCATE"); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_name_varno]); var->value = DirectFunctionCall1(namein, CStringGetDatum(trigdata->tg_trigger->tgname)); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_when_varno]); if (TRIGGER_FIRED_BEFORE(trigdata->tg_event)) var->value = CStringGetTextDatum("BEFORE"); else if (TRIGGER_FIRED_AFTER(trigdata->tg_event)) var->value = CStringGetTextDatum("AFTER"); else elog(ERROR, "unrecognized trigger execution time: not BEFORE or AFTER"); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_level_varno]); if (TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) var->value = CStringGetTextDatum("ROW"); else if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event)) var->value = CStringGetTextDatum("STATEMENT"); else elog(ERROR, "unrecognized trigger event type: not ROW or STATEMENT"); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_relid_varno]); var->value = ObjectIdGetDatum(trigdata->tg_relation->rd_id); var->isnull = false; var->freeval = false; var = (PLpgSQL_var *) (estate.datums[func->tg_relname_varno]); var->value = DirectFunctionCall1(namein, CStringGetDatum(RelationGetRelationName(trigdata->tg_relation))); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_table_name_varno]); var->value = DirectFunctionCall1(namein, CStringGetDatum(RelationGetRelationName(trigdata->tg_relation))); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_table_schema_varno]); var->value = DirectFunctionCall1(namein, CStringGetDatum( get_namespace_name( RelationGetNamespace( trigdata->tg_relation)))); var->isnull = false; var->freeval = true; var = (PLpgSQL_var *) (estate.datums[func->tg_nargs_varno]); var->value = Int16GetDatum(trigdata->tg_trigger->tgnargs); var->isnull = false; var->freeval = false; var = (PLpgSQL_var *) (estate.datums[func->tg_argv_varno]); if (trigdata->tg_trigger->tgnargs > 0) { /* * For historical reasons, tg_argv[] subscripts start at zero not one. * So we can't use construct_array(). */ int nelems = trigdata->tg_trigger->tgnargs; Datum *elems; int dims[1]; int lbs[1]; elems = palloc(sizeof(Datum) * nelems); for (i = 0; i < nelems; i++) elems[i] = CStringGetTextDatum(trigdata->tg_trigger->tgargs[i]); dims[0] = nelems; lbs[0] = 0; var->value = PointerGetDatum(construct_md_array(elems, NULL, 1, dims, lbs, TEXTOID, -1, false, 'i')); var->isnull = false; var->freeval = true; } else { var->value = (Datum) 0; var->isnull = true; var->freeval = false; } estate.err_text = gettext_noop("during function entry"); /* * Set the magic variable FOUND to false */ exec_set_found(&estate, false); /* * Let the instrumentation plugin peek at this function */ if (*plugin_ptr && (*plugin_ptr)->func_beg) ((*plugin_ptr)->func_beg) (&estate, func); /* * Now call the toplevel block of statements */ estate.err_text = NULL; estate.err_stmt = (PLpgSQL_stmt *) (func->action); rc = exec_stmt_block(&estate, func->action); if (rc != PLPGSQL_RC_RETURN) { estate.err_stmt = NULL; estate.err_text = NULL; /* * Provide a more helpful message if a CONTINUE or RAISE has been used * outside the context it can work in. */ if (rc == PLPGSQL_RC_CONTINUE) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("CONTINUE cannot be used outside a loop"))); else if (rc == PLPGSQL_RC_RERAISE) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE without parameters cannot be used outside an exception handler"))); else ereport(ERROR, (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT), errmsg("control reached end of trigger procedure without RETURN"))); } estate.err_stmt = NULL; estate.err_text = gettext_noop("during function exit"); if (estate.retisset) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("trigger procedure cannot return a set"))); /* * Check that the returned tuple structure has the same attributes, the * relation that fired the trigger has. A per-statement trigger always * needs to return NULL, so we ignore any return value the function itself * produces (XXX: is this a good idea?) * * XXX This way it is possible, that the trigger returns a tuple where * attributes don't have the correct atttypmod's length. It's up to the * trigger's programmer to ensure that this doesn't happen. Jan */ if (estate.retisnull || TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event)) rettup = NULL; else { TupleConversionMap *tupmap; rettup = (HeapTuple) DatumGetPointer(estate.retval); /* check rowtype compatibility */ tupmap = convert_tuples_by_position(estate.rettupdesc, trigdata->tg_relation->rd_att, gettext_noop("returned row structure does not match the structure of the triggering table")); /* it might need conversion */ if (tupmap) rettup = do_convert_tuple(rettup, tupmap); /* no need to free map, we're about to return anyway */ /* Copy tuple to upper executor memory */ rettup = SPI_copytuple(rettup); } /* * Let the instrumentation plugin peek at this function */ if (*plugin_ptr && (*plugin_ptr)->func_end) ((*plugin_ptr)->func_end) (&estate, func); /* Clean up any leftover temporary memory */ plpgsql_destroy_econtext(&estate); exec_eval_cleanup(&estate); /* * Pop the error context stack */ error_context_stack = plerrcontext.previous; /* * Return the trigger's result */ return rettup; } /* * error context callback to let us supply a call-stack traceback */ static void plpgsql_exec_error_callback(void *arg) { PLpgSQL_execstate *estate = (PLpgSQL_execstate *) arg; /* if we are doing RAISE, don't report its location */ if (estate->err_text == raise_skip_msg) return; if (estate->err_text != NULL) { /* * We don't expend the cycles to run gettext() on err_text unless we * actually need it. Therefore, places that set up err_text should * use gettext_noop() to ensure the strings get recorded in the * message dictionary. * * If both err_text and err_stmt are set, use the err_text as * description, but report the err_stmt's line number. When err_stmt * is not set, we're in function entry/exit, or some such place not * attached to a specific line number. */ if (estate->err_stmt != NULL) { /* * translator: last %s is a phrase such as "during statement block * local variable initialization" */ errcontext("PL/pgSQL function \"%s\" line %d %s", estate->func->fn_name, estate->err_stmt->lineno, _(estate->err_text)); } else { /* * translator: last %s is a phrase such as "while storing call * arguments into local variables" */ errcontext("PL/pgSQL function \"%s\" %s", estate->func->fn_name, _(estate->err_text)); } } else if (estate->err_stmt != NULL) { /* translator: last %s is a plpgsql statement type name */ errcontext("PL/pgSQL function \"%s\" line %d at %s", estate->func->fn_name, estate->err_stmt->lineno, plpgsql_stmt_typename(estate->err_stmt)); } else errcontext("PL/pgSQL function \"%s\"", estate->func->fn_name); } /* ---------- * Support function for initializing local execution variables * ---------- */ static PLpgSQL_datum * copy_plpgsql_datum(PLpgSQL_datum *datum) { PLpgSQL_datum *result; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *new = palloc(sizeof(PLpgSQL_var)); memcpy(new, datum, sizeof(PLpgSQL_var)); /* Ensure the value is null (possibly not needed?) */ new->value = 0; new->isnull = true; new->freeval = false; result = (PLpgSQL_datum *) new; } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *new = palloc(sizeof(PLpgSQL_rec)); memcpy(new, datum, sizeof(PLpgSQL_rec)); /* Ensure the value is null (possibly not needed?) */ new->tup = NULL; new->tupdesc = NULL; new->freetup = false; new->freetupdesc = false; result = (PLpgSQL_datum *) new; } break; case PLPGSQL_DTYPE_ROW: case PLPGSQL_DTYPE_RECFIELD: case PLPGSQL_DTYPE_ARRAYELEM: /* * These datum records are read-only at runtime, so no need to * copy them */ result = datum; break; default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); result = NULL; /* keep compiler quiet */ break; } return result; } static bool exception_matches_conditions(ErrorData *edata, PLpgSQL_condition *cond) { for (; cond != NULL; cond = cond->next) { int sqlerrstate = cond->sqlerrstate; /* * OTHERS matches everything *except* query-canceled; if you're * foolish enough, you can match that explicitly. */ if (sqlerrstate == 0) { if (edata->sqlerrcode != ERRCODE_QUERY_CANCELED) return true; } /* Exact match? */ else if (edata->sqlerrcode == sqlerrstate) return true; /* Category match? */ else if (ERRCODE_IS_CATEGORY(sqlerrstate) && ERRCODE_TO_CATEGORY(edata->sqlerrcode) == sqlerrstate) return true; } return false; } /* ---------- * exec_stmt_block Execute a block of statements * ---------- */ static int exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block) { volatile int rc = -1; int i; int n; /* * First initialize all variables declared in this block */ estate->err_text = gettext_noop("during statement block local variable initialization"); for (i = 0; i < block->n_initvars; i++) { n = block->initvarnos[i]; switch (estate->datums[n]->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) (estate->datums[n]); /* free any old value, in case re-entering block */ free_var(var); /* Initially it contains a NULL */ var->value = (Datum) 0; var->isnull = true; if (var->default_val == NULL) { /* * If needed, give the datatype a chance to reject * NULLs, by assigning a NULL to the variable. We * claim the value is of type UNKNOWN, not the var's * datatype, else coercion will be skipped. (Do this * before the notnull check to be consistent with * exec_assign_value.) */ if (!var->datatype->typinput.fn_strict) { bool valIsNull = true; exec_assign_value(estate, (PLpgSQL_datum *) var, (Datum) 0, UNKNOWNOID, &valIsNull); } if (var->notnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("variable \"%s\" declared NOT NULL cannot default to NULL", var->refname))); } else { exec_assign_expr(estate, (PLpgSQL_datum *) var, var->default_val); } } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) (estate->datums[n]); if (rec->freetup) { heap_freetuple(rec->tup); rec->freetup = false; } if (rec->freetupdesc) { FreeTupleDesc(rec->tupdesc); rec->freetupdesc = false; } rec->tup = NULL; rec->tupdesc = NULL; } break; case PLPGSQL_DTYPE_RECFIELD: case PLPGSQL_DTYPE_ARRAYELEM: break; default: elog(ERROR, "unrecognized dtype: %d", estate->datums[n]->dtype); } } if (block->exceptions) { /* * Execute the statements in the block's body inside a sub-transaction */ MemoryContext oldcontext = CurrentMemoryContext; ResourceOwner oldowner = CurrentResourceOwner; ExprContext *old_eval_econtext = estate->eval_econtext; estate->err_text = gettext_noop("during statement block entry"); BeginInternalSubTransaction(NULL); /* Want to run statements inside function's memory context */ MemoryContextSwitchTo(oldcontext); PG_TRY(); { /* * We need to run the block's statements with a new eval_econtext * that belongs to the current subtransaction; if we try to use * the outer econtext then ExprContext shutdown callbacks will be * called at the wrong times. */ plpgsql_create_econtext(estate); estate->err_text = NULL; /* Run the block's statements */ rc = exec_stmts(estate, block->body); estate->err_text = gettext_noop("during statement block exit"); /* * If the block ended with RETURN, we may need to copy the return * value out of the subtransaction eval_context. This is * currently only needed for scalar result types --- rowtype * values will always exist in the function's own memory context. */ if (rc == PLPGSQL_RC_RETURN && !estate->retisset && !estate->retisnull && estate->rettupdesc == NULL) { int16 resTypLen; bool resTypByVal; get_typlenbyval(estate->rettype, &resTypLen, &resTypByVal); estate->retval = datumCopy(estate->retval, resTypByVal, resTypLen); } /* Commit the inner transaction, return to outer xact context */ ReleaseCurrentSubTransaction(); MemoryContextSwitchTo(oldcontext); CurrentResourceOwner = oldowner; /* * Revert to outer eval_econtext. (The inner one was * automatically cleaned up during subxact exit.) */ estate->eval_econtext = old_eval_econtext; /* * AtEOSubXact_SPI() should not have popped any SPI context, but * just in case it did, make sure we remain connected. */ SPI_restore_connection(); } PG_CATCH(); { ErrorData *edata; ListCell *e; estate->err_text = gettext_noop("during exception cleanup"); /* Save error info */ MemoryContextSwitchTo(oldcontext); edata = CopyErrorData(); FlushErrorState(); /* Abort the inner transaction */ RollbackAndReleaseCurrentSubTransaction(); MemoryContextSwitchTo(oldcontext); CurrentResourceOwner = oldowner; /* Revert to outer eval_econtext */ estate->eval_econtext = old_eval_econtext; /* * If AtEOSubXact_SPI() popped any SPI context of the subxact, it * will have left us in a disconnected state. We need this hack * to return to connected state. */ SPI_restore_connection(); /* Look for a matching exception handler */ foreach(e, block->exceptions->exc_list) { PLpgSQL_exception *exception = (PLpgSQL_exception *) lfirst(e); if (exception_matches_conditions(edata, exception->conditions)) { /* * Initialize the magic SQLSTATE and SQLERRM variables for * the exception block. We needn't do this until we have * found a matching exception. */ PLpgSQL_var *state_var; PLpgSQL_var *errm_var; state_var = (PLpgSQL_var *) estate->datums[block->exceptions->sqlstate_varno]; errm_var = (PLpgSQL_var *) estate->datums[block->exceptions->sqlerrm_varno]; assign_text_var(state_var, unpack_sql_state(edata->sqlerrcode)); assign_text_var(errm_var, edata->message); estate->err_text = NULL; rc = exec_stmts(estate, exception->action); free_var(state_var); state_var->value = (Datum) 0; state_var->isnull = true; free_var(errm_var); errm_var->value = (Datum) 0; errm_var->isnull = true; /* re-throw error if requested by handler */ if (rc == PLPGSQL_RC_RERAISE) ReThrowError(edata); break; } } /* If no match found, re-throw the error */ if (e == NULL) ReThrowError(edata); else FreeErrorData(edata); } PG_END_TRY(); } else { /* * Just execute the statements in the block's body */ estate->err_text = NULL; rc = exec_stmts(estate, block->body); } estate->err_text = NULL; /* * Handle the return code. */ switch (rc) { case PLPGSQL_RC_OK: case PLPGSQL_RC_RETURN: case PLPGSQL_RC_CONTINUE: case PLPGSQL_RC_RERAISE: return rc; case PLPGSQL_RC_EXIT: /* * This is intentionally different from the handling of RC_EXIT * for loops: to match a block, we require a match by label. */ if (estate->exitlabel == NULL) return PLPGSQL_RC_EXIT; if (block->label == NULL) return PLPGSQL_RC_EXIT; if (strcmp(block->label, estate->exitlabel) != 0) return PLPGSQL_RC_EXIT; estate->exitlabel = NULL; return PLPGSQL_RC_OK; default: elog(ERROR, "unrecognized rc: %d", rc); } return PLPGSQL_RC_OK; } /* ---------- * exec_stmts Iterate over a list of statements * as long as their return code is OK * ---------- */ static int exec_stmts(PLpgSQL_execstate *estate, List *stmts) { ListCell *s; if (stmts == NIL) { /* * Ensure we do a CHECK_FOR_INTERRUPTS() even though there is no * statement. This prevents hangup in a tight loop if, for instance, * there is a LOOP construct with an empty body. */ CHECK_FOR_INTERRUPTS(); return PLPGSQL_RC_OK; } foreach(s, stmts) { PLpgSQL_stmt *stmt = (PLpgSQL_stmt *) lfirst(s); int rc = exec_stmt(estate, stmt); if (rc != PLPGSQL_RC_OK) return rc; } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt Distribute one statement to the statements * type specific execution function. * ---------- */ static int exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt) { PLpgSQL_stmt *save_estmt; int rc = -1; save_estmt = estate->err_stmt; estate->err_stmt = stmt; /* Let the plugin know that we are about to execute this statement */ if (*plugin_ptr && (*plugin_ptr)->stmt_beg) ((*plugin_ptr)->stmt_beg) (estate, stmt); CHECK_FOR_INTERRUPTS(); switch ((enum PLpgSQL_stmt_types) stmt->cmd_type) { case PLPGSQL_STMT_BLOCK: rc = exec_stmt_block(estate, (PLpgSQL_stmt_block *) stmt); break; case PLPGSQL_STMT_ASSIGN: rc = exec_stmt_assign(estate, (PLpgSQL_stmt_assign *) stmt); break; case PLPGSQL_STMT_PERFORM: rc = exec_stmt_perform(estate, (PLpgSQL_stmt_perform *) stmt); break; case PLPGSQL_STMT_GETDIAG: rc = exec_stmt_getdiag(estate, (PLpgSQL_stmt_getdiag *) stmt); break; case PLPGSQL_STMT_IF: rc = exec_stmt_if(estate, (PLpgSQL_stmt_if *) stmt); break; case PLPGSQL_STMT_CASE: rc = exec_stmt_case(estate, (PLpgSQL_stmt_case *) stmt); break; case PLPGSQL_STMT_LOOP: rc = exec_stmt_loop(estate, (PLpgSQL_stmt_loop *) stmt); break; case PLPGSQL_STMT_WHILE: rc = exec_stmt_while(estate, (PLpgSQL_stmt_while *) stmt); break; case PLPGSQL_STMT_FORI: rc = exec_stmt_fori(estate, (PLpgSQL_stmt_fori *) stmt); break; case PLPGSQL_STMT_FORS: rc = exec_stmt_fors(estate, (PLpgSQL_stmt_fors *) stmt); break; case PLPGSQL_STMT_FORC: rc = exec_stmt_forc(estate, (PLpgSQL_stmt_forc *) stmt); break; case PLPGSQL_STMT_EXIT: rc = exec_stmt_exit(estate, (PLpgSQL_stmt_exit *) stmt); break; case PLPGSQL_STMT_RETURN: rc = exec_stmt_return(estate, (PLpgSQL_stmt_return *) stmt); break; case PLPGSQL_STMT_RETURN_NEXT: rc = exec_stmt_return_next(estate, (PLpgSQL_stmt_return_next *) stmt); break; case PLPGSQL_STMT_RETURN_QUERY: rc = exec_stmt_return_query(estate, (PLpgSQL_stmt_return_query *) stmt); break; case PLPGSQL_STMT_RAISE: rc = exec_stmt_raise(estate, (PLpgSQL_stmt_raise *) stmt); break; case PLPGSQL_STMT_EXECSQL: rc = exec_stmt_execsql(estate, (PLpgSQL_stmt_execsql *) stmt); break; case PLPGSQL_STMT_DYNEXECUTE: rc = exec_stmt_dynexecute(estate, (PLpgSQL_stmt_dynexecute *) stmt); break; case PLPGSQL_STMT_DYNFORS: rc = exec_stmt_dynfors(estate, (PLpgSQL_stmt_dynfors *) stmt); break; case PLPGSQL_STMT_OPEN: rc = exec_stmt_open(estate, (PLpgSQL_stmt_open *) stmt); break; case PLPGSQL_STMT_FETCH: rc = exec_stmt_fetch(estate, (PLpgSQL_stmt_fetch *) stmt); break; case PLPGSQL_STMT_CLOSE: rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt); break; default: estate->err_stmt = save_estmt; elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type); } /* Let the plugin know that we have finished executing this statement */ if (*plugin_ptr && (*plugin_ptr)->stmt_end) ((*plugin_ptr)->stmt_end) (estate, stmt); estate->err_stmt = save_estmt; return rc; } /* ---------- * exec_stmt_assign Evaluate an expression and * put the result into a variable. * ---------- */ static int exec_stmt_assign(PLpgSQL_execstate *estate, PLpgSQL_stmt_assign *stmt) { Assert(stmt->varno >= 0); exec_assign_expr(estate, estate->datums[stmt->varno], stmt->expr); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_perform Evaluate query and discard result (but set * FOUND depending on whether at least one row * was returned). * ---------- */ static int exec_stmt_perform(PLpgSQL_execstate *estate, PLpgSQL_stmt_perform *stmt) { PLpgSQL_expr *expr = stmt->expr; (void) exec_run_select(estate, expr, 0, NULL); exec_set_found(estate, (estate->eval_processed != 0)); exec_eval_cleanup(estate); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_getdiag Put internal PG information into * specified variables. * ---------- */ static int exec_stmt_getdiag(PLpgSQL_execstate *estate, PLpgSQL_stmt_getdiag *stmt) { ListCell *lc; foreach(lc, stmt->diag_items) { PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc); PLpgSQL_datum *var; bool isnull = false; if (diag_item->target <= 0) continue; var = estate->datums[diag_item->target]; if (var == NULL) continue; switch (diag_item->kind) { case PLPGSQL_GETDIAG_ROW_COUNT: exec_assign_value(estate, var, UInt32GetDatum(estate->eval_processed), INT4OID, &isnull); break; case PLPGSQL_GETDIAG_RESULT_OID: exec_assign_value(estate, var, ObjectIdGetDatum(estate->eval_lastoid), OIDOID, &isnull); break; default: elog(ERROR, "unrecognized attribute request: %d", diag_item->kind); } } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_if Evaluate a bool expression and * execute the true or false body * conditionally. * ---------- */ static int exec_stmt_if(PLpgSQL_execstate *estate, PLpgSQL_stmt_if *stmt) { bool value; bool isnull; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (!isnull && value) { if (stmt->true_body != NIL) return exec_stmts(estate, stmt->true_body); } else { if (stmt->false_body != NIL) return exec_stmts(estate, stmt->false_body); } return PLPGSQL_RC_OK; } /*----------- * exec_stmt_case *----------- */ static int exec_stmt_case(PLpgSQL_execstate *estate, PLpgSQL_stmt_case *stmt) { PLpgSQL_var *t_var = NULL; bool isnull; ListCell *l; if (stmt->t_expr != NULL) { /* simple case */ Datum t_val; Oid t_oid; t_val = exec_eval_expr(estate, stmt->t_expr, &isnull, &t_oid); t_var = (PLpgSQL_var *) estate->datums[stmt->t_varno]; /* * When expected datatype is different from real, change it. Note that * what we're modifying here is an execution copy of the datum, so * this doesn't affect the originally stored function parse tree. */ if (t_var->datatype->typoid != t_oid) t_var->datatype = plpgsql_build_datatype(t_oid, -1); /* now we can assign to the variable */ exec_assign_value(estate, (PLpgSQL_datum *) t_var, t_val, t_oid, &isnull); exec_eval_cleanup(estate); } /* Now search for a successful WHEN clause */ foreach(l, stmt->case_when_list) { PLpgSQL_case_when *cwt = (PLpgSQL_case_when *) lfirst(l); bool value; value = exec_eval_boolean(estate, cwt->expr, &isnull); exec_eval_cleanup(estate); if (!isnull && value) { /* Found it */ /* We can now discard any value we had for the temp variable */ if (t_var != NULL) { free_var(t_var); t_var->value = (Datum) 0; t_var->isnull = true; } /* Evaluate the statement(s), and we're done */ return exec_stmts(estate, cwt->stmts); } } /* We can now discard any value we had for the temp variable */ if (t_var != NULL) { free_var(t_var); t_var->value = (Datum) 0; t_var->isnull = true; } /* SQL2003 mandates this error if there was no ELSE clause */ if (!stmt->have_else) ereport(ERROR, (errcode(ERRCODE_CASE_NOT_FOUND), errmsg("case not found"), errhint("CASE statement is missing ELSE part."))); /* Evaluate the ELSE statements, and we're done */ return exec_stmts(estate, stmt->else_stmts); } /* ---------- * exec_stmt_loop Loop over statements until * an exit occurs. * ---------- */ static int exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt) { for (;;) { int rc = exec_stmts(estate, stmt->body); switch (rc) { case PLPGSQL_RC_OK: break; case PLPGSQL_RC_EXIT: if (estate->exitlabel == NULL) return PLPGSQL_RC_OK; if (stmt->label == NULL) return PLPGSQL_RC_EXIT; 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: case PLPGSQL_RC_RERAISE: return rc; default: elog(ERROR, "unrecognized rc: %d", rc); } } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_while Loop over statements as long * as an expression evaluates to * true or an exit occurs. * ---------- */ static int exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt) { for (;;) { int rc; bool value; bool isnull; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (isnull || !value) break; rc = exec_stmts(estate, stmt->body); switch (rc) { case PLPGSQL_RC_OK: break; case PLPGSQL_RC_EXIT: if (estate->exitlabel == NULL) return PLPGSQL_RC_OK; if (stmt->label == NULL) return PLPGSQL_RC_EXIT; 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 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: case PLPGSQL_RC_RERAISE: return rc; default: elog(ERROR, "unrecognized rc: %d", rc); } } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_fori Iterate an integer variable * from a lower to an upper value * incrementing or decrementing by the BY value * ---------- */ static int exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt) { PLpgSQL_var *var; Datum value; bool isnull; Oid valtype; int32 loop_value; int32 end_value; int32 step_value; bool found = false; int rc = PLPGSQL_RC_OK; var = (PLpgSQL_var *) (estate->datums[stmt->var->dno]); /* * Get the value of the lower bound */ value = exec_eval_expr(estate, stmt->lower, &isnull, &valtype); value = exec_cast_value(value, valtype, var->datatype->typoid, &(var->datatype->typinput), var->datatype->typioparam, var->datatype->atttypmod, isnull); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("lower bound of FOR loop cannot be null"))); loop_value = DatumGetInt32(value); exec_eval_cleanup(estate); /* * Get the value of the upper bound */ value = exec_eval_expr(estate, stmt->upper, &isnull, &valtype); value = exec_cast_value(value, valtype, var->datatype->typoid, &(var->datatype->typinput), var->datatype->typioparam, var->datatype->atttypmod, isnull); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("upper bound of FOR loop cannot be null"))); end_value = DatumGetInt32(value); exec_eval_cleanup(estate); /* * Get the step value */ if (stmt->step) { value = exec_eval_expr(estate, stmt->step, &isnull, &valtype); value = exec_cast_value(value, valtype, var->datatype->typoid, &(var->datatype->typinput), var->datatype->typioparam, var->datatype->atttypmod, isnull); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("BY value of FOR loop cannot be null"))); step_value = DatumGetInt32(value); exec_eval_cleanup(estate); if (step_value <= 0) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("BY value of FOR loop must be greater than zero"))); } else step_value = 1; /* * Now do the loop */ for (;;) { /* * Check against upper bound */ if (stmt->reverse) { if (loop_value < end_value) break; } else { if (loop_value > end_value) break; } found = true; /* looped at least once */ /* * Assign current value to loop var */ var->value = Int32GetDatum(loop_value); var->isnull = false; /* * Execute the statements */ rc = exec_stmts(estate, stmt->body); if (rc == PLPGSQL_RC_RETURN || rc == PLPGSQL_RC_RERAISE) break; /* break out of the loop */ else if (rc == PLPGSQL_RC_EXIT) { if (estate->exitlabel == NULL) /* unlabelled exit, finish the current loop */ rc = PLPGSQL_RC_OK; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* labelled exit, matches the current stmt's label */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } /* * 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) /* unlabelled continue, so re-run the current loop */ rc = PLPGSQL_RC_OK; else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches named continue, so re-run loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } else { /* * otherwise, this is a named 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 value, unless it would overflow, in which * case exit the loop. */ if (stmt->reverse) { if ((int32) (loop_value - step_value) > loop_value) break; loop_value -= step_value; } else { if ((int32) (loop_value + step_value) < loop_value) break; loop_value += step_value; } } /* * Set the FOUND variable to indicate the result of executing the loop * (namely, whether we looped one or more times). This must be set here so * that it does not interfere with the value of the FOUND variable inside * the loop processing itself. */ exec_set_found(estate, found); return rc; } /* ---------- * exec_stmt_fors Execute a query, assign each * tuple to a record or row and * execute a group of statements * for it. * ---------- */ static int exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt) { Portal portal; int rc; /* * Open the implicit cursor for the statement using exec_run_select */ exec_run_select(estate, stmt->query, 0, &portal); /* * Execute the loop */ rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, true); /* * Close the implicit cursor */ SPI_cursor_close(portal); return rc; } /* ---------- * exec_stmt_forc Execute a loop for each row from a cursor. * ---------- */ static int exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt) { PLpgSQL_var *curvar; char *curname = NULL; PLpgSQL_expr *query; ParamListInfo paramLI; Portal portal; int rc; /* ---------- * Get the cursor variable and if it has an assigned name, check * that it's not in use currently. * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (!curvar->isnull) { curname = TextDatumGetCString(curvar->value); if (SPI_cursor_find(curname) != NULL) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_CURSOR), errmsg("cursor \"%s\" already in use", curname))); } /* ---------- * Open the cursor just like an OPEN command * * Note: parser should already have checked that statement supplies * args iff cursor needs them, but we check again to be safe. * ---------- */ if (stmt->argquery != NULL) { /* ---------- * OPEN CURSOR with args. We fake a SELECT ... INTO ... * statement to evaluate the args and put 'em into the * internal row. * ---------- */ PLpgSQL_stmt_execsql set_args; if (curvar->cursor_explicit_argrow < 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments given for cursor without arguments"))); memset(&set_args, 0, sizeof(set_args)); set_args.cmd_type = PLPGSQL_STMT_EXECSQL; set_args.lineno = stmt->lineno; set_args.sqlstmt = stmt->argquery; set_args.into = true; /* XXX historically this has not been STRICT */ set_args.row = (PLpgSQL_row *) (estate->datums[curvar->cursor_explicit_argrow]); if (exec_stmt_execsql(estate, &set_args) != PLPGSQL_RC_OK) elog(ERROR, "open cursor failed during argument processing"); } else { if (curvar->cursor_explicit_argrow >= 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments required for cursor"))); } query = curvar->cursor_explicit_expr; Assert(query); if (query->plan == NULL) exec_prepare_plan(estate, query, curvar->cursor_options); /* * Set up ParamListInfo (note this is only carrying a hook function, * not any actual data values, at this point) */ paramLI = setup_param_list(estate, query); /* * Open the cursor (the paramlist will get copied into the portal) */ portal = SPI_cursor_open_with_paramlist(curname, query->plan, paramLI, estate->readonly_func); if (portal == NULL) elog(ERROR, "could not open cursor: %s", SPI_result_code_string(SPI_result)); /* don't need paramlist any more */ if (paramLI) pfree(paramLI); /* * If cursor variable was NULL, store the generated portal name in it */ if (curname == NULL) assign_text_var(curvar, portal->name); /* * Execute the loop. We can't prefetch because the cursor is accessible * to the user, for instance via UPDATE WHERE CURRENT OF within the loop. */ rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, false); /* ---------- * Close portal, and restore cursor variable if it was initially NULL. * ---------- */ SPI_cursor_close(portal); if (curname == NULL) { free_var(curvar); curvar->value = (Datum) 0; curvar->isnull = true; } if (curname) pfree(curname); return rc; } /* ---------- * 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 / continue has a condition, evaluate it */ if (stmt->cond != NULL) { bool value; bool isnull; value = exec_eval_boolean(estate, stmt->cond, &isnull); exec_eval_cleanup(estate); if (isnull || value == false) return PLPGSQL_RC_OK; } estate->exitlabel = stmt->label; if (stmt->is_exit) return PLPGSQL_RC_EXIT; else return PLPGSQL_RC_CONTINUE; } /* ---------- * exec_stmt_return Evaluate an expression and start * returning from the function. * ---------- */ static int exec_stmt_return(PLpgSQL_execstate *estate, PLpgSQL_stmt_return *stmt) { /* * If processing a set-returning PL/PgSQL function, the final RETURN * indicates that the function is finished producing tuples. The rest of * the work will be done at the top level. */ if (estate->retisset) return PLPGSQL_RC_RETURN; /* initialize for null result (possibly a tuple) */ estate->retval = (Datum) 0; estate->rettupdesc = NULL; estate->retisnull = true; if (stmt->retvarno >= 0) { PLpgSQL_datum *retvar = estate->datums[stmt->retvarno]; switch (retvar->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) retvar; estate->retval = var->value; estate->retisnull = var->isnull; estate->rettype = var->datatype->typoid; } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) retvar; if (HeapTupleIsValid(rec->tup)) { estate->retval = PointerGetDatum(rec->tup); estate->rettupdesc = rec->tupdesc; estate->retisnull = false; } } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) retvar; Assert(row->rowtupdesc); estate->retval = PointerGetDatum(make_tuple_from_row(estate, row, row->rowtupdesc)); if (DatumGetPointer(estate->retval) == NULL) /* should not happen */ elog(ERROR, "row not compatible with its own tupdesc"); estate->rettupdesc = row->rowtupdesc; estate->retisnull = false; } break; default: elog(ERROR, "unrecognized dtype: %d", retvar->dtype); } return PLPGSQL_RC_RETURN; } if (stmt->expr != NULL) { if (estate->retistuple) { exec_run_select(estate, stmt->expr, 1, NULL); if (estate->eval_processed > 0) { estate->retval = PointerGetDatum(estate->eval_tuptable->vals[0]); estate->rettupdesc = estate->eval_tuptable->tupdesc; estate->retisnull = false; } } else { /* Normal case for scalar results */ estate->retval = exec_eval_expr(estate, stmt->expr, &(estate->retisnull), &(estate->rettype)); } return PLPGSQL_RC_RETURN; } /* * Special hack for function returning VOID: instead of NULL, return a * non-null VOID value. This is of dubious importance but is kept for * backwards compatibility. Note that the only other way to get here is * to have written "RETURN NULL" in a function returning tuple. */ if (estate->fn_rettype == VOIDOID) { estate->retval = (Datum) 0; estate->retisnull = false; estate->rettype = VOIDOID; } return PLPGSQL_RC_RETURN; } /* ---------- * exec_stmt_return_next Evaluate an expression and add it to the * list of tuples returned by the current * SRF. * ---------- */ static int exec_stmt_return_next(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_next *stmt) { TupleDesc tupdesc; int natts; HeapTuple tuple = NULL; bool free_tuple = false; if (!estate->retisset) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot use RETURN NEXT in a non-SETOF function"))); if (estate->tuple_store == NULL) exec_init_tuple_store(estate); /* rettupdesc will be filled by exec_init_tuple_store */ tupdesc = estate->rettupdesc; natts = tupdesc->natts; if (stmt->retvarno >= 0) { PLpgSQL_datum *retvar = estate->datums[stmt->retvarno]; switch (retvar->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) retvar; Datum retval = var->value; bool isNull = var->isnull; if (natts != 1) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("wrong result type supplied in RETURN NEXT"))); /* coerce type if needed */ retval = exec_simple_cast_value(retval, var->datatype->typoid, tupdesc->attrs[0]->atttypid, tupdesc->attrs[0]->atttypmod, isNull); tuplestore_putvalues(estate->tuple_store, tupdesc, &retval, &isNull); } break; case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) retvar; TupleConversionMap *tupmap; if (!HeapTupleIsValid(rec->tup)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned" " record is indeterminate."))); tupmap = convert_tuples_by_position(rec->tupdesc, tupdesc, gettext_noop("wrong record type supplied in RETURN NEXT")); tuple = rec->tup; /* it might need conversion */ if (tupmap) { tuple = do_convert_tuple(tuple, tupmap); free_conversion_map(tupmap); } } break; case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) retvar; tuple = make_tuple_from_row(estate, row, tupdesc); if (tuple == NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("wrong record type supplied in RETURN NEXT"))); free_tuple = true; } break; default: elog(ERROR, "unrecognized dtype: %d", retvar->dtype); break; } } else if (stmt->expr) { Datum retval; bool isNull; Oid rettype; if (natts != 1) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("wrong result type supplied in RETURN NEXT"))); retval = exec_eval_expr(estate, stmt->expr, &isNull, &rettype); /* coerce type if needed */ retval = exec_simple_cast_value(retval, rettype, tupdesc->attrs[0]->atttypid, tupdesc->attrs[0]->atttypmod, isNull); tuplestore_putvalues(estate->tuple_store, tupdesc, &retval, &isNull); exec_eval_cleanup(estate); } else { ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RETURN NEXT must have a parameter"))); } if (HeapTupleIsValid(tuple)) { tuplestore_puttuple(estate->tuple_store, tuple); if (free_tuple) heap_freetuple(tuple); } return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_return_query Evaluate a query and add it to the * list of tuples returned by the current * SRF. * ---------- */ static int exec_stmt_return_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_return_query *stmt) { Portal portal; uint32 processed = 0; TupleConversionMap *tupmap; if (!estate->retisset) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot use RETURN QUERY in a non-SETOF function"))); if (estate->tuple_store == NULL) exec_init_tuple_store(estate); if (stmt->query != NULL) { /* static query */ exec_run_select(estate, stmt->query, 0, &portal); } else { /* RETURN QUERY EXECUTE */ Assert(stmt->dynquery != NULL); portal = exec_dynquery_with_params(estate, stmt->dynquery, stmt->params); } tupmap = convert_tuples_by_position(portal->tupDesc, estate->rettupdesc, gettext_noop("structure of query does not match function result type")); while (true) { int i; SPI_cursor_fetch(portal, true, 50); if (SPI_processed == 0) break; for (i = 0; i < SPI_processed; i++) { HeapTuple tuple = SPI_tuptable->vals[i]; if (tupmap) tuple = do_convert_tuple(tuple, tupmap); tuplestore_puttuple(estate->tuple_store, tuple); if (tupmap) heap_freetuple(tuple); processed++; } SPI_freetuptable(SPI_tuptable); } if (tupmap) free_conversion_map(tupmap); SPI_freetuptable(SPI_tuptable); SPI_cursor_close(portal); estate->eval_processed = processed; exec_set_found(estate, processed != 0); return PLPGSQL_RC_OK; } static void exec_init_tuple_store(PLpgSQL_execstate *estate) { ReturnSetInfo *rsi = estate->rsi; MemoryContext oldcxt; ResourceOwner oldowner; /* * Check caller can handle a set result in the way we want */ if (!rsi || !IsA(rsi, ReturnSetInfo) || (rsi->allowedModes & SFRM_Materialize) == 0 || rsi->expectedDesc == NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); /* * Switch to the right memory context and resource owner for storing * the tuplestore for return set. If we're within a subtransaction opened * for an exception-block, for example, we must still create the * tuplestore in the resource owner that was active when this function was * entered, and not in the subtransaction resource owner. */ oldcxt = MemoryContextSwitchTo(estate->tuple_store_cxt); oldowner = CurrentResourceOwner; CurrentResourceOwner = estate->tuple_store_owner; estate->tuple_store = tuplestore_begin_heap(rsi->allowedModes & SFRM_Materialize_Random, false, work_mem); CurrentResourceOwner = oldowner; MemoryContextSwitchTo(oldcxt); estate->rettupdesc = rsi->expectedDesc; } /* ---------- * exec_stmt_raise Build a message and throw it with elog() * ---------- */ static int exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt) { int err_code = 0; char *condname = NULL; char *err_message = NULL; char *err_detail = NULL; char *err_hint = NULL; ListCell *lc; /* RAISE with no parameters: re-throw current exception */ if (stmt->condname == NULL && stmt->message == NULL && stmt->options == NIL) return PLPGSQL_RC_RERAISE; if (stmt->condname) { err_code = plpgsql_recognize_err_condition(stmt->condname, true); condname = pstrdup(stmt->condname); } if (stmt->message) { StringInfoData ds; ListCell *current_param; char *cp; initStringInfo(&ds); current_param = list_head(stmt->params); for (cp = stmt->message; *cp; cp++) { /* * Occurrences of a single % are replaced by the next parameter's * external representation. Double %'s are converted to one %. */ if (cp[0] == '%') { Oid paramtypeid; Datum paramvalue; bool paramisnull; char *extval; if (cp[1] == '%') { appendStringInfoChar(&ds, '%'); cp++; continue; } if (current_param == NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("too few parameters specified for RAISE"))); paramvalue = exec_eval_expr(estate, (PLpgSQL_expr *) lfirst(current_param), ¶misnull, ¶mtypeid); if (paramisnull) extval = ""; else extval = convert_value_to_string(paramvalue, paramtypeid); appendStringInfoString(&ds, extval); current_param = lnext(current_param); exec_eval_cleanup(estate); } else appendStringInfoChar(&ds, cp[0]); } /* * If more parameters were specified than were required to process the * format string, throw an error */ if (current_param != NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("too many parameters specified for RAISE"))); err_message = ds.data; /* No pfree(ds.data), the pfree(err_message) does it */ } foreach(lc, stmt->options) { PLpgSQL_raise_option *opt = (PLpgSQL_raise_option *) lfirst(lc); Datum optionvalue; bool optionisnull; Oid optiontypeid; char *extval; optionvalue = exec_eval_expr(estate, opt->expr, &optionisnull, &optiontypeid); if (optionisnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("RAISE statement option cannot be null"))); extval = convert_value_to_string(optionvalue, optiontypeid); switch (opt->opt_type) { case PLPGSQL_RAISEOPTION_ERRCODE: if (err_code) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE option already specified: %s", "ERRCODE"))); err_code = plpgsql_recognize_err_condition(extval, true); condname = pstrdup(extval); break; case PLPGSQL_RAISEOPTION_MESSAGE: if (err_message) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE option already specified: %s", "MESSAGE"))); err_message = pstrdup(extval); break; case PLPGSQL_RAISEOPTION_DETAIL: if (err_detail) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE option already specified: %s", "DETAIL"))); err_detail = pstrdup(extval); break; case PLPGSQL_RAISEOPTION_HINT: if (err_hint) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("RAISE option already specified: %s", "HINT"))); err_hint = pstrdup(extval); break; default: elog(ERROR, "unrecognized raise option: %d", opt->opt_type); } exec_eval_cleanup(estate); } /* Default code if nothing specified */ if (err_code == 0 && stmt->elog_level >= ERROR) err_code = ERRCODE_RAISE_EXCEPTION; /* Default error message if nothing specified */ if (err_message == NULL) { if (condname) { err_message = condname; condname = NULL; } else err_message = pstrdup(unpack_sql_state(err_code)); } /* * Throw the error (may or may not come back) */ estate->err_text = raise_skip_msg; /* suppress traceback of raise */ ereport(stmt->elog_level, (err_code ? errcode(err_code) : 0, errmsg_internal("%s", err_message), (err_detail != NULL) ? errdetail("%s", err_detail) : 0, (err_hint != NULL) ? errhint("%s", err_hint) : 0)); estate->err_text = NULL; /* un-suppress... */ if (condname != NULL) pfree(condname); if (err_message != NULL) pfree(err_message); if (err_detail != NULL) pfree(err_detail); if (err_hint != NULL) pfree(err_hint); return PLPGSQL_RC_OK; } /* ---------- * Initialize a mostly empty execution state * ---------- */ static void plpgsql_estate_setup(PLpgSQL_execstate *estate, PLpgSQL_function *func, ReturnSetInfo *rsi) { /* this link will be restored at exit from plpgsql_call_handler */ func->cur_estate = estate; estate->func = func; estate->retval = (Datum) 0; estate->retisnull = true; estate->rettype = InvalidOid; estate->fn_rettype = func->fn_rettype; estate->retistuple = func->fn_retistuple; estate->retisset = func->fn_retset; estate->readonly_func = func->fn_readonly; estate->rettupdesc = NULL; estate->exitlabel = NULL; estate->tuple_store = NULL; if (rsi) { estate->tuple_store_cxt = rsi->econtext->ecxt_per_query_memory; estate->tuple_store_owner = CurrentResourceOwner; } else { estate->tuple_store_cxt = NULL; estate->tuple_store_owner = NULL; } estate->rsi = rsi; estate->found_varno = func->found_varno; estate->ndatums = func->ndatums; estate->datums = palloc(sizeof(PLpgSQL_datum *) * estate->ndatums); /* caller is expected to fill the datums array */ estate->eval_tuptable = NULL; estate->eval_processed = 0; estate->eval_lastoid = InvalidOid; estate->eval_econtext = NULL; estate->cur_expr = NULL; estate->err_stmt = NULL; estate->err_text = NULL; estate->plugin_info = NULL; /* * Create an EState and ExprContext for evaluation of simple expressions. */ plpgsql_create_econtext(estate); /* * Let the plugin see this function before we initialize any local * PL/pgSQL variables - note that we also give the plugin a few function * pointers so it can call back into PL/pgSQL for doing things like * variable assignments and stack traces */ if (*plugin_ptr) { (*plugin_ptr)->error_callback = plpgsql_exec_error_callback; (*plugin_ptr)->assign_expr = exec_assign_expr; if ((*plugin_ptr)->func_setup) ((*plugin_ptr)->func_setup) (estate, func); } } /* ---------- * Release temporary memory used by expression/subselect evaluation * * NB: the result of the evaluation is no longer valid after this is done, * unless it is a pass-by-value datatype. * ---------- */ static void exec_eval_cleanup(PLpgSQL_execstate *estate) { /* Clear result of a full SPI_execute */ if (estate->eval_tuptable != NULL) SPI_freetuptable(estate->eval_tuptable); estate->eval_tuptable = NULL; /* Clear result of exec_eval_simple_expr (but keep the econtext) */ if (estate->eval_econtext != NULL) ResetExprContext(estate->eval_econtext); } /* ---------- * Generate a prepared plan * ---------- */ static void exec_prepare_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, int cursorOptions) { SPIPlanPtr plan; /* * The grammar can't conveniently set expr->func while building the * parse tree, so make sure it's set before parser hooks need it. */ expr->func = estate->func; /* * Generate and save the plan */ plan = SPI_prepare_params(expr->query, (ParserSetupHook) plpgsql_parser_setup, (void *) expr, cursorOptions); if (plan == NULL) { /* Some SPI errors deserve specific error messages */ switch (SPI_result) { case SPI_ERROR_COPY: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot COPY to/from client in PL/pgSQL"))); case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot begin/end transactions in PL/pgSQL"), errhint("Use a BEGIN block with an EXCEPTION clause instead."))); default: elog(ERROR, "SPI_prepare_params failed for \"%s\": %s", expr->query, SPI_result_code_string(SPI_result)); } } expr->plan = SPI_saveplan(plan); SPI_freeplan(plan); exec_simple_check_plan(expr); } /* ---------- * exec_stmt_execsql Execute an SQL statement (possibly with INTO). * ---------- */ static int exec_stmt_execsql(PLpgSQL_execstate *estate, PLpgSQL_stmt_execsql *stmt) { ParamListInfo paramLI; long tcount; int rc; PLpgSQL_expr *expr = stmt->sqlstmt; /* * On the first call for this statement generate the plan, and detect * whether the statement is INSERT/UPDATE/DELETE */ if (expr->plan == NULL) { ListCell *l; exec_prepare_plan(estate, expr, 0); stmt->mod_stmt = false; foreach(l, expr->plan->plancache_list) { CachedPlanSource *plansource = (CachedPlanSource *) lfirst(l); ListCell *l2; foreach(l2, plansource->plan->stmt_list) { PlannedStmt *p = (PlannedStmt *) lfirst(l2); if (IsA(p, PlannedStmt) && p->canSetTag) { if (p->commandType == CMD_INSERT || p->commandType == CMD_UPDATE || p->commandType == CMD_DELETE) stmt->mod_stmt = true; } } } } /* * Set up ParamListInfo (note this is only carrying a hook function, * not any actual data values, at this point) */ paramLI = setup_param_list(estate, expr); /* * If we have INTO, then we only need one row back ... but if we have INTO * STRICT, ask for two rows, so that we can verify the statement returns * only one. INSERT/UPDATE/DELETE are always treated strictly. Without * INTO, just run the statement to completion (tcount = 0). * * We could just ask for two rows always when using INTO, but there are * some cases where demanding the extra row costs significant time, eg by * forcing completion of a sequential scan. So don't do it unless we need * to enforce strictness. */ if (stmt->into) { if (stmt->strict || stmt->mod_stmt) tcount = 2; else tcount = 1; } else tcount = 0; /* * Execute the plan */ rc = SPI_execute_plan_with_paramlist(expr->plan, paramLI, estate->readonly_func, tcount); /* * Check for error, and set FOUND if appropriate (for historical reasons * we set FOUND only for certain query types). Also Assert that we * identified the statement type the same as SPI did. */ switch (rc) { case SPI_OK_SELECT: Assert(!stmt->mod_stmt); exec_set_found(estate, (SPI_processed != 0)); break; case SPI_OK_INSERT: case SPI_OK_UPDATE: case SPI_OK_DELETE: case SPI_OK_INSERT_RETURNING: case SPI_OK_UPDATE_RETURNING: case SPI_OK_DELETE_RETURNING: Assert(stmt->mod_stmt); exec_set_found(estate, (SPI_processed != 0)); break; case SPI_OK_SELINTO: case SPI_OK_UTILITY: Assert(!stmt->mod_stmt); break; case SPI_OK_REWRITTEN: Assert(!stmt->mod_stmt); /* * The command was rewritten into another kind of command. It's * not clear what FOUND would mean in that case (and SPI doesn't * return the row count either), so just set it to false. */ exec_set_found(estate, false); break; default: elog(ERROR, "SPI_execute_plan_with_paramlist failed executing query \"%s\": %s", expr->query, SPI_result_code_string(rc)); } /* All variants should save result info for GET DIAGNOSTICS */ estate->eval_processed = SPI_processed; estate->eval_lastoid = SPI_lastoid; /* Process INTO if present */ if (stmt->into) { SPITupleTable *tuptab = SPI_tuptable; uint32 n = SPI_processed; PLpgSQL_rec *rec = NULL; PLpgSQL_row *row = NULL; /* If the statement did not return a tuple table, complain */ if (tuptab == NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("INTO used with a command that cannot return data"))); /* Determine if we assign to a record or a row */ if (stmt->rec != NULL) rec = (PLpgSQL_rec *) (estate->datums[stmt->rec->dno]); else if (stmt->row != NULL) row = (PLpgSQL_row *) (estate->datums[stmt->row->dno]); else elog(ERROR, "unsupported target"); /* * If SELECT ... INTO specified STRICT, and the query didn't find * exactly one row, throw an error. If STRICT was not specified, then * allow the query to find any number of rows. */ if (n == 0) { if (stmt->strict) ereport(ERROR, (errcode(ERRCODE_NO_DATA_FOUND), errmsg("query returned no rows"))); /* set the target to NULL(s) */ exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); } else { if (n > 1 && (stmt->strict || stmt->mod_stmt)) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_ROWS), errmsg("query returned more than one row"))); /* Put the first result row into the target */ exec_move_row(estate, rec, row, tuptab->vals[0], tuptab->tupdesc); } /* Clean up */ SPI_freetuptable(SPI_tuptable); } else { /* If the statement returned a tuple table, complain */ if (SPI_tuptable != NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query has no destination for result data"), (rc == SPI_OK_SELECT) ? errhint("If you want to discard the results of a SELECT, use PERFORM instead.") : 0)); } if (paramLI) pfree(paramLI); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_dynexecute Execute a dynamic SQL query * (possibly with INTO). * ---------- */ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynexecute *stmt) { Datum query; bool isnull = false; Oid restype; char *querystr; int exec_res; /* * First we evaluate the string expression after the EXECUTE keyword. Its * result is the querystring we have to execute. */ query = exec_eval_expr(estate, stmt->query, &isnull, &restype); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("query string argument of EXECUTE is null"))); /* Get the C-String representation */ querystr = convert_value_to_string(query, restype); exec_eval_cleanup(estate); /* * Execute the query without preparing a saved plan. */ if (stmt->params) { PreparedParamsData *ppd; ppd = exec_eval_using_params(estate, stmt->params); exec_res = SPI_execute_with_args(querystr, ppd->nargs, ppd->types, ppd->values, ppd->nulls, estate->readonly_func, 0); free_params_data(ppd); } else exec_res = SPI_execute(querystr, estate->readonly_func, 0); switch (exec_res) { case SPI_OK_SELECT: case SPI_OK_INSERT: case SPI_OK_UPDATE: case SPI_OK_DELETE: case SPI_OK_INSERT_RETURNING: case SPI_OK_UPDATE_RETURNING: case SPI_OK_DELETE_RETURNING: case SPI_OK_UTILITY: case SPI_OK_REWRITTEN: break; case 0: /* * Also allow a zero return, which implies the querystring * contained no commands. */ break; case SPI_OK_SELINTO: /* * We want to disallow SELECT INTO for now, because its behavior * is not consistent with SELECT INTO in a normal plpgsql context. * (We need to reimplement EXECUTE to parse the string as a * plpgsql command, not just feed it to SPI_execute.) However, * CREATE AS should be allowed ... and since it produces the same * parsetree as SELECT INTO, there's no way to tell the difference * except to look at the source text. Wotta kluge! */ { char *ptr; for (ptr = querystr; *ptr; ptr++) if (!scanner_isspace(*ptr)) break; if (*ptr == 'S' || *ptr == 's') ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("EXECUTE of SELECT ... INTO is not implemented"))); break; } /* Some SPI errors deserve specific error messages */ case SPI_ERROR_COPY: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot COPY to/from client in PL/pgSQL"))); case SPI_ERROR_TRANSACTION: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot begin/end transactions in PL/pgSQL"), errhint("Use a BEGIN block with an EXCEPTION clause instead."))); default: elog(ERROR, "SPI_execute failed executing query \"%s\": %s", querystr, SPI_result_code_string(exec_res)); break; } /* Save result info for GET DIAGNOSTICS */ estate->eval_processed = SPI_processed; estate->eval_lastoid = SPI_lastoid; /* Process INTO if present */ if (stmt->into) { SPITupleTable *tuptab = SPI_tuptable; uint32 n = SPI_processed; PLpgSQL_rec *rec = NULL; PLpgSQL_row *row = NULL; /* If the statement did not return a tuple table, complain */ if (tuptab == NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("INTO used with a command that cannot return data"))); /* Determine if we assign to a record or a row */ if (stmt->rec != NULL) rec = (PLpgSQL_rec *) (estate->datums[stmt->rec->dno]); else if (stmt->row != NULL) row = (PLpgSQL_row *) (estate->datums[stmt->row->dno]); else elog(ERROR, "unsupported target"); /* * If SELECT ... INTO specified STRICT, and the query didn't find * exactly one row, throw an error. If STRICT was not specified, then * allow the query to find any number of rows. */ if (n == 0) { if (stmt->strict) ereport(ERROR, (errcode(ERRCODE_NO_DATA_FOUND), errmsg("query returned no rows"))); /* set the target to NULL(s) */ exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); } else { if (n > 1 && stmt->strict) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_ROWS), errmsg("query returned more than one row"))); /* Put the first result row into the target */ exec_move_row(estate, rec, row, tuptab->vals[0], tuptab->tupdesc); } } else { /* * It might be a good idea to raise an error if the query returned * tuples that are being ignored, but historically we have not done * that. */ } /* Release any result from SPI_execute, as well as the querystring */ SPI_freetuptable(SPI_tuptable); pfree(querystr); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_dynfors Execute a dynamic query, assign each * tuple to a record or row and * execute a group of statements * for it. * ---------- */ static int exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt) { Portal portal; int rc; portal = exec_dynquery_with_params(estate, stmt->query, stmt->params); /* * Execute the loop */ rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, true); /* * Close the implicit cursor */ SPI_cursor_close(portal); return rc; } /* ---------- * exec_stmt_open Execute an OPEN cursor statement * ---------- */ static int exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt) { PLpgSQL_var *curvar; char *curname = NULL; PLpgSQL_expr *query; Portal portal; ParamListInfo paramLI; bool isnull; /* ---------- * Get the cursor variable and if it has an assigned name, check * that it's not in use currently. * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (!curvar->isnull) { curname = TextDatumGetCString(curvar->value); if (SPI_cursor_find(curname) != NULL) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_CURSOR), errmsg("cursor \"%s\" already in use", curname))); } /* ---------- * Process the OPEN according to it's type. * ---------- */ if (stmt->query != NULL) { /* ---------- * This is an OPEN refcursor FOR SELECT ... * * We just make sure the query is planned. The real work is * done downstairs. * ---------- */ query = stmt->query; if (query->plan == NULL) exec_prepare_plan(estate, query, stmt->cursor_options); } else if (stmt->dynquery != NULL) { /* ---------- * This is an OPEN refcursor FOR EXECUTE ... * ---------- */ Datum queryD; Oid restype; char *querystr; SPIPlanPtr curplan; /* ---------- * We evaluate the string expression after the * EXECUTE keyword. It's result is the querystring we have * to execute. * ---------- */ queryD = exec_eval_expr(estate, stmt->dynquery, &isnull, &restype); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("query string argument of EXECUTE is null"))); /* Get the C-String representation */ querystr = convert_value_to_string(queryD, restype); exec_eval_cleanup(estate); /* ---------- * Now we prepare a query plan for it and open a cursor * ---------- */ curplan = SPI_prepare_cursor(querystr, 0, NULL, stmt->cursor_options); if (curplan == NULL) elog(ERROR, "SPI_prepare_cursor failed for \"%s\": %s", querystr, SPI_result_code_string(SPI_result)); portal = SPI_cursor_open(curname, curplan, NULL, NULL, estate->readonly_func); if (portal == NULL) elog(ERROR, "could not open cursor for query \"%s\": %s", querystr, SPI_result_code_string(SPI_result)); pfree(querystr); SPI_freeplan(curplan); /* * If cursor variable was NULL, store the generated portal name in it */ if (curname == NULL) assign_text_var(curvar, portal->name); return PLPGSQL_RC_OK; } else { /* ---------- * This is an OPEN cursor * * Note: parser should already have checked that statement supplies * args iff cursor needs them, but we check again to be safe. * ---------- */ if (stmt->argquery != NULL) { /* ---------- * OPEN CURSOR with args. We fake a SELECT ... INTO ... * statement to evaluate the args and put 'em into the * internal row. * ---------- */ PLpgSQL_stmt_execsql set_args; if (curvar->cursor_explicit_argrow < 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments given for cursor without arguments"))); memset(&set_args, 0, sizeof(set_args)); set_args.cmd_type = PLPGSQL_STMT_EXECSQL; set_args.lineno = stmt->lineno; set_args.sqlstmt = stmt->argquery; set_args.into = true; /* XXX historically this has not been STRICT */ set_args.row = (PLpgSQL_row *) (estate->datums[curvar->cursor_explicit_argrow]); if (exec_stmt_execsql(estate, &set_args) != PLPGSQL_RC_OK) elog(ERROR, "open cursor failed during argument processing"); } else { if (curvar->cursor_explicit_argrow >= 0) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("arguments required for cursor"))); } query = curvar->cursor_explicit_expr; if (query->plan == NULL) exec_prepare_plan(estate, query, curvar->cursor_options); } /* * Set up ParamListInfo (note this is only carrying a hook function, * not any actual data values, at this point) */ paramLI = setup_param_list(estate, query); /* * Open the cursor */ portal = SPI_cursor_open_with_paramlist(curname, query->plan, paramLI, estate->readonly_func); if (portal == NULL) elog(ERROR, "could not open cursor: %s", SPI_result_code_string(SPI_result)); /* * If cursor variable was NULL, store the generated portal name in it */ if (curname == NULL) assign_text_var(curvar, portal->name); if (curname) pfree(curname); if (paramLI) pfree(paramLI); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_fetch Fetch from a cursor into a target, or just * move the current position of the cursor * ---------- */ static int exec_stmt_fetch(PLpgSQL_execstate *estate, PLpgSQL_stmt_fetch *stmt) { PLpgSQL_var *curvar = NULL; PLpgSQL_rec *rec = NULL; PLpgSQL_row *row = NULL; long how_many = stmt->how_many; SPITupleTable *tuptab; Portal portal; char *curname; uint32 n; /* ---------- * Get the portal of the cursor by name * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (curvar->isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("cursor variable \"%s\" is null", curvar->refname))); curname = TextDatumGetCString(curvar->value); portal = SPI_cursor_find(curname); if (portal == NULL) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_CURSOR), errmsg("cursor \"%s\" does not exist", curname))); pfree(curname); /* Calculate position for FETCH_RELATIVE or FETCH_ABSOLUTE */ if (stmt->expr) { bool isnull; /* XXX should be doing this in LONG not INT width */ how_many = exec_eval_integer(estate, stmt->expr, &isnull); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("relative or absolute cursor position is null"))); exec_eval_cleanup(estate); } if (!stmt->is_move) { /* ---------- * Determine if we fetch into a record or a row * ---------- */ if (stmt->rec != NULL) rec = (PLpgSQL_rec *) (estate->datums[stmt->rec->dno]); else if (stmt->row != NULL) row = (PLpgSQL_row *) (estate->datums[stmt->row->dno]); else elog(ERROR, "unsupported target"); /* ---------- * Fetch 1 tuple from the cursor * ---------- */ SPI_scroll_cursor_fetch(portal, stmt->direction, how_many); tuptab = SPI_tuptable; n = SPI_processed; /* ---------- * Set the target appropriately. * ---------- */ if (n == 0) exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); else exec_move_row(estate, rec, row, tuptab->vals[0], tuptab->tupdesc); SPI_freetuptable(tuptab); } else { /* Move the cursor */ SPI_scroll_cursor_move(portal, stmt->direction, how_many); n = SPI_processed; } /* Set the ROW_COUNT and the global FOUND variable appropriately. */ estate->eval_processed = n; exec_set_found(estate, n != 0); return PLPGSQL_RC_OK; } /* ---------- * exec_stmt_close Close a cursor * ---------- */ static int exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt) { PLpgSQL_var *curvar = NULL; Portal portal; char *curname; /* ---------- * Get the portal of the cursor by name * ---------- */ curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]); if (curvar->isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("cursor variable \"%s\" is null", curvar->refname))); curname = TextDatumGetCString(curvar->value); portal = SPI_cursor_find(curname); if (portal == NULL) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_CURSOR), errmsg("cursor \"%s\" does not exist", curname))); pfree(curname); /* ---------- * And close it. * ---------- */ SPI_cursor_close(portal); return PLPGSQL_RC_OK; } /* ---------- * exec_assign_expr Put an expression's result into * a variable. * ---------- */ static void exec_assign_expr(PLpgSQL_execstate *estate, PLpgSQL_datum *target, PLpgSQL_expr *expr) { Datum value; Oid valtype; bool isnull = false; value = exec_eval_expr(estate, expr, &isnull, &valtype); exec_assign_value(estate, target, value, valtype, &isnull); exec_eval_cleanup(estate); } /* ---------- * exec_assign_value Put a value into a target field * ---------- */ static void exec_assign_value(PLpgSQL_execstate *estate, PLpgSQL_datum *target, Datum value, Oid valtype, bool *isNull) { switch (target->dtype) { case PLPGSQL_DTYPE_VAR: { /* * Target is a variable */ PLpgSQL_var *var = (PLpgSQL_var *) target; Datum newvalue; newvalue = exec_cast_value(value, valtype, var->datatype->typoid, &(var->datatype->typinput), var->datatype->typioparam, var->datatype->atttypmod, *isNull); if (*isNull && var->notnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("null value cannot be assigned to variable \"%s\" declared NOT NULL", var->refname))); /* * If type is by-reference, make sure we have a freshly * palloc'd copy; the originally passed value may not live as * long as the variable! But we don't need to re-copy if * exec_cast_value performed a conversion; its output must * already be palloc'd. */ if (!var->datatype->typbyval && !*isNull) { if (newvalue == value) newvalue = datumCopy(newvalue, false, var->datatype->typlen); } /* * Now free the old value. (We can't do this any earlier * because of the possibility that we are assigning the var's * old value to it, eg "foo := foo". We could optimize out * the assignment altogether in such cases, but it's too * infrequent to be worth testing for.) */ free_var(var); var->value = newvalue; var->isnull = *isNull; if (!var->datatype->typbyval && !*isNull) var->freeval = true; break; } case PLPGSQL_DTYPE_ROW: { /* * Target is a row variable */ PLpgSQL_row *row = (PLpgSQL_row *) target; /* Source must be of RECORD or composite type */ if (!type_is_rowtype(valtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot assign non-composite value to a row variable"))); if (*isNull) { /* If source is null, just assign nulls to the row */ exec_move_row(estate, NULL, row, NULL, NULL); } else { HeapTupleHeader td; Oid tupType; int32 tupTypmod; TupleDesc tupdesc; HeapTupleData tmptup; /* Else source is a tuple Datum, safe to do this: */ td = DatumGetHeapTupleHeader(value); /* Extract rowtype info and find a tupdesc */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod); /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup.t_self)); tmptup.t_tableOid = InvalidOid; tmptup.t_data = td; exec_move_row(estate, NULL, row, &tmptup, tupdesc); ReleaseTupleDesc(tupdesc); } break; } case PLPGSQL_DTYPE_REC: { /* * Target is a record variable */ PLpgSQL_rec *rec = (PLpgSQL_rec *) target; /* Source must be of RECORD or composite type */ if (!type_is_rowtype(valtype)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("cannot assign non-composite value to a record variable"))); if (*isNull) { /* If source is null, just assign nulls to the record */ exec_move_row(estate, rec, NULL, NULL, NULL); } else { HeapTupleHeader td; Oid tupType; int32 tupTypmod; TupleDesc tupdesc; HeapTupleData tmptup; /* Else source is a tuple Datum, safe to do this: */ td = DatumGetHeapTupleHeader(value); /* Extract rowtype info and find a tupdesc */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod); /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); ItemPointerSetInvalid(&(tmptup.t_self)); tmptup.t_tableOid = InvalidOid; tmptup.t_data = td; exec_move_row(estate, rec, NULL, &tmptup, tupdesc); ReleaseTupleDesc(tupdesc); } break; } case PLPGSQL_DTYPE_RECFIELD: { /* * Target is a field of a record */ PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) target; PLpgSQL_rec *rec; int fno; HeapTuple newtup; int natts; Datum *values; bool *nulls; bool *replaces; void *mustfree; bool attisnull; Oid atttype; int32 atttypmod; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); /* * Check that there is already a tuple in the record. We need * that because records don't have any predefined field * structure. */ if (!HeapTupleIsValid(rec->tup)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); /* * Get the number of the records field to change and the * number of attributes in the tuple. Note: disallow system * column names because the code below won't cope. */ fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno <= 0) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); fno--; natts = rec->tupdesc->natts; /* * Set up values/control arrays for heap_modify_tuple. For all * the attributes except the one we want to replace, use the * value that's in the old tuple. */ values = palloc(sizeof(Datum) * natts); nulls = palloc(sizeof(bool) * natts); replaces = palloc(sizeof(bool) * natts); memset(replaces, false, sizeof(bool) * natts); replaces[fno] = true; /* * Now insert the new value, being careful to cast it to the * right type. */ atttype = SPI_gettypeid(rec->tupdesc, fno + 1); atttypmod = rec->tupdesc->attrs[fno]->atttypmod; attisnull = *isNull; values[fno] = exec_simple_cast_value(value, valtype, atttype, atttypmod, attisnull); nulls[fno] = attisnull; /* * Avoid leaking the result of exec_simple_cast_value, if it * performed a conversion to a pass-by-ref type. */ if (!attisnull && values[fno] != value && !get_typbyval(atttype)) mustfree = DatumGetPointer(values[fno]); else mustfree = NULL; /* * Now call heap_modify_tuple() to create a new tuple that * replaces the old one in the record. */ newtup = heap_modify_tuple(rec->tup, rec->tupdesc, values, nulls, replaces); if (rec->freetup) heap_freetuple(rec->tup); rec->tup = newtup; rec->freetup = true; pfree(values); pfree(nulls); pfree(replaces); if (mustfree) pfree(mustfree); break; } case PLPGSQL_DTYPE_ARRAYELEM: { int nsubscripts; int i; PLpgSQL_expr *subscripts[MAXDIM]; int subscriptvals[MAXDIM]; bool oldarrayisnull; Oid arraytypeid, arrayelemtypeid; int16 arraytyplen, elemtyplen; bool elemtypbyval; char elemtypalign; Datum oldarraydatum, coerced_value; ArrayType *oldarrayval; ArrayType *newarrayval; /* * Target is an element of an array * * To handle constructs like x[1][2] := something, we have to * be prepared to deal with a chain of arrayelem datums. Chase * back to find the base array datum, and save the subscript * expressions as we go. (We are scanning right to left here, * but want to evaluate the subscripts left-to-right to * minimize surprises.) */ nsubscripts = 0; do { PLpgSQL_arrayelem *arrayelem = (PLpgSQL_arrayelem *) target; if (nsubscripts >= MAXDIM) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)", nsubscripts, MAXDIM))); subscripts[nsubscripts++] = arrayelem->subscript; target = estate->datums[arrayelem->arrayparentno]; } while (target->dtype == PLPGSQL_DTYPE_ARRAYELEM); /* Fetch current value of array datum */ exec_eval_datum(estate, target, &arraytypeid, &oldarraydatum, &oldarrayisnull); arrayelemtypeid = get_element_type(arraytypeid); if (!OidIsValid(arrayelemtypeid)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("subscripted object is not an array"))); get_typlenbyvalalign(arrayelemtypeid, &elemtyplen, &elemtypbyval, &elemtypalign); arraytyplen = get_typlen(arraytypeid); /* * Evaluate the subscripts, switch into left-to-right order. * Like ExecEvalArrayRef(), complain if any subscript is null. */ for (i = 0; i < nsubscripts; i++) { bool subisnull; subscriptvals[i] = exec_eval_integer(estate, subscripts[nsubscripts - 1 - i], &subisnull); if (subisnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("array subscript in assignment must not be null"))); } /* Coerce source value to match array element type. */ coerced_value = exec_simple_cast_value(value, valtype, arrayelemtypeid, -1, *isNull); /* * If the original array is null, cons up an empty array so * that the assignment can proceed; we'll end with a * one-element array containing just the assigned-to * subscript. This only works for varlena arrays, though; for * fixed-length array types we skip the assignment. We can't * support assignment of a null entry into a fixed-length * array, either, so that's a no-op too. This is all ugly but * corresponds to the current behavior of ExecEvalArrayRef(). */ if (arraytyplen > 0 && /* fixed-length array? */ (oldarrayisnull || *isNull)) return; if (oldarrayisnull) oldarrayval = construct_empty_array(arrayelemtypeid); else oldarrayval = (ArrayType *) DatumGetPointer(oldarraydatum); /* * Build the modified array value. */ newarrayval = array_set(oldarrayval, nsubscripts, subscriptvals, coerced_value, *isNull, arraytyplen, elemtyplen, elemtypbyval, elemtypalign); /* * Avoid leaking the result of exec_simple_cast_value, if it * performed a conversion to a pass-by-ref type. */ if (!*isNull && coerced_value != value && !elemtypbyval) pfree(DatumGetPointer(coerced_value)); /* * Assign the new array to the base variable. It's never NULL * at this point. */ *isNull = false; exec_assign_value(estate, target, PointerGetDatum(newarrayval), arraytypeid, isNull); /* * Avoid leaking the modified array value, too. */ pfree(newarrayval); break; } default: elog(ERROR, "unrecognized dtype: %d", target->dtype); } } /* * exec_eval_datum Get current value of a PLpgSQL_datum * * The type oid, value in Datum format, and null flag are returned. * * At present this doesn't handle PLpgSQL_expr or PLpgSQL_arrayelem datums. * * NOTE: caller must not modify the returned value, since it points right * at the stored value in the case of pass-by-reference datatypes. In some * cases we have to palloc a return value, and in such cases we put it into * the estate's short-term memory context. */ static void exec_eval_datum(PLpgSQL_execstate *estate, PLpgSQL_datum *datum, Oid *typeid, Datum *value, bool *isnull) { MemoryContext oldcontext; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) datum; *typeid = var->datatype->typoid; *value = var->value; *isnull = var->isnull; break; } case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) datum; HeapTuple tup; if (!row->rowtupdesc) /* should not happen */ elog(ERROR, "row variable has no tupdesc"); /* Make sure we have a valid type/typmod setting */ BlessTupleDesc(row->rowtupdesc); oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory); tup = make_tuple_from_row(estate, row, row->rowtupdesc); if (tup == NULL) /* should not happen */ elog(ERROR, "row not compatible with its own tupdesc"); MemoryContextSwitchTo(oldcontext); *typeid = row->rowtupdesc->tdtypeid; *value = HeapTupleGetDatum(tup); *isnull = false; break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; HeapTupleData worktup; if (!HeapTupleIsValid(rec->tup)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); Assert(rec->tupdesc != NULL); /* Make sure we have a valid type/typmod setting */ BlessTupleDesc(rec->tupdesc); /* * In a trigger, the NEW and OLD parameters are likely to be * on-disk tuples that don't have the desired Datum fields. * Copy the tuple body and insert the right values. */ oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory); heap_copytuple_with_tuple(rec->tup, &worktup); HeapTupleHeaderSetDatumLength(worktup.t_data, worktup.t_len); HeapTupleHeaderSetTypeId(worktup.t_data, rec->tupdesc->tdtypeid); HeapTupleHeaderSetTypMod(worktup.t_data, rec->tupdesc->tdtypmod); MemoryContextSwitchTo(oldcontext); *typeid = rec->tupdesc->tdtypeid; *value = HeapTupleGetDatum(&worktup); *isnull = false; break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; int fno; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); if (!HeapTupleIsValid(rec->tup)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno == SPI_ERROR_NOATTRIBUTE) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); *typeid = SPI_gettypeid(rec->tupdesc, fno); *value = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull); break; } default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); } } /* * exec_get_datum_type Get datatype of a PLpgSQL_datum * * This is the same logic as in exec_eval_datum, except that it can handle * some cases where exec_eval_datum has to fail; specifically, we may have * a tupdesc but no row value for a record variable. (This currently can * happen only for a trigger's NEW/OLD records.) */ Oid exec_get_datum_type(PLpgSQL_execstate *estate, PLpgSQL_datum *datum) { Oid typeid; switch (datum->dtype) { case PLPGSQL_DTYPE_VAR: { PLpgSQL_var *var = (PLpgSQL_var *) datum; typeid = var->datatype->typoid; break; } case PLPGSQL_DTYPE_ROW: { PLpgSQL_row *row = (PLpgSQL_row *) datum; if (!row->rowtupdesc) /* should not happen */ elog(ERROR, "row variable has no tupdesc"); /* Make sure we have a valid type/typmod setting */ BlessTupleDesc(row->rowtupdesc); typeid = row->rowtupdesc->tdtypeid; break; } case PLPGSQL_DTYPE_REC: { PLpgSQL_rec *rec = (PLpgSQL_rec *) datum; if (rec->tupdesc == NULL) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); /* Make sure we have a valid type/typmod setting */ BlessTupleDesc(rec->tupdesc); typeid = rec->tupdesc->tdtypeid; break; } case PLPGSQL_DTYPE_RECFIELD: { PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum; PLpgSQL_rec *rec; int fno; rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]); if (rec->tupdesc == NULL) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); fno = SPI_fnumber(rec->tupdesc, recfield->fieldname); if (fno == SPI_ERROR_NOATTRIBUTE) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, recfield->fieldname))); typeid = SPI_gettypeid(rec->tupdesc, fno); break; } default: elog(ERROR, "unrecognized dtype: %d", datum->dtype); typeid = InvalidOid; /* keep compiler quiet */ break; } return typeid; } /* * exec_get_rec_fieldtype Get datatype of a PLpgSQL record field * * Also returns the field number to *fieldno. */ Oid exec_get_rec_fieldtype(PLpgSQL_rec *rec, const char *fieldname, int *fieldno) { Oid typeid; int fno; if (rec->tupdesc == NULL) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("record \"%s\" is not assigned yet", rec->refname), errdetail("The tuple structure of a not-yet-assigned record is indeterminate."))); fno = SPI_fnumber(rec->tupdesc, fieldname); if (fno == SPI_ERROR_NOATTRIBUTE) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("record \"%s\" has no field \"%s\"", rec->refname, fieldname))); typeid = SPI_gettypeid(rec->tupdesc, fno); *fieldno = fno; return typeid; } /* ---------- * exec_eval_integer Evaluate an expression, coerce result to int4 * * Note we do not do exec_eval_cleanup here; the caller must do it at * some later point. (We do this because the caller may be holding the * results of other, pass-by-reference, expression evaluations, such as * an array value to be subscripted. Also see notes in exec_eval_simple_expr * about allocation of the parameter array.) * ---------- */ static int exec_eval_integer(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull) { Datum exprdatum; Oid exprtypeid; exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid); exprdatum = exec_simple_cast_value(exprdatum, exprtypeid, INT4OID, -1, *isNull); return DatumGetInt32(exprdatum); } /* ---------- * exec_eval_boolean Evaluate an expression, coerce result to bool * * Note we do not do exec_eval_cleanup here; the caller must do it at * some later point. * ---------- */ static bool exec_eval_boolean(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull) { Datum exprdatum; Oid exprtypeid; exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid); exprdatum = exec_simple_cast_value(exprdatum, exprtypeid, BOOLOID, -1, *isNull); return DatumGetBool(exprdatum); } /* ---------- * exec_eval_expr Evaluate an expression and return * the result Datum. * * NOTE: caller must do exec_eval_cleanup when done with the Datum. * ---------- */ static Datum exec_eval_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, bool *isNull, Oid *rettype) { Datum result = 0; int rc; /* * If first time through, create a plan for this expression. */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, 0); /* * If this is a simple expression, bypass SPI and use the executor * directly */ if (exec_eval_simple_expr(estate, expr, &result, isNull, rettype)) return result; /* * Else do it the hard way via exec_run_select */ rc = exec_run_select(estate, expr, 2, NULL); if (rc != SPI_OK_SELECT) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("query \"%s\" did not return data", expr->query))); /* * If there are no rows selected, the result is NULL. */ if (estate->eval_processed == 0) { *isNull = true; return (Datum) 0; } /* * Check that the expression returned one single Datum */ if (estate->eval_processed > 1) ereport(ERROR, (errcode(ERRCODE_CARDINALITY_VIOLATION), errmsg("query \"%s\" returned more than one row", expr->query))); if (estate->eval_tuptable->tupdesc->natts != 1) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg_plural("query \"%s\" returned %d column", "query \"%s\" returned %d columns", estate->eval_tuptable->tupdesc->natts, expr->query, estate->eval_tuptable->tupdesc->natts))); /* * Return the result and its type */ *rettype = SPI_gettypeid(estate->eval_tuptable->tupdesc, 1); return SPI_getbinval(estate->eval_tuptable->vals[0], estate->eval_tuptable->tupdesc, 1, isNull); } /* ---------- * exec_run_select Execute a select query * ---------- */ static int exec_run_select(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, long maxtuples, Portal *portalP) { ParamListInfo paramLI; int rc; /* * On the first call for this expression generate the plan */ if (expr->plan == NULL) exec_prepare_plan(estate, expr, 0); /* * Set up ParamListInfo (note this is only carrying a hook function, * not any actual data values, at this point) */ paramLI = setup_param_list(estate, expr); /* * If a portal was requested, put the query into the portal */ if (portalP != NULL) { *portalP = SPI_cursor_open_with_paramlist(NULL, expr->plan, paramLI, estate->readonly_func); if (*portalP == NULL) elog(ERROR, "could not open implicit cursor for query \"%s\": %s", expr->query, SPI_result_code_string(SPI_result)); if (paramLI) pfree(paramLI); return SPI_OK_CURSOR; } /* * Execute the query */ rc = SPI_execute_plan_with_paramlist(expr->plan, paramLI, estate->readonly_func, maxtuples); if (rc != SPI_OK_SELECT) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query \"%s\" is not a SELECT", expr->query))); /* Save query results for eventual cleanup */ Assert(estate->eval_tuptable == NULL); estate->eval_tuptable = SPI_tuptable; estate->eval_processed = SPI_processed; estate->eval_lastoid = SPI_lastoid; if (paramLI) pfree(paramLI); return rc; } /* * exec_for_query --- execute body of FOR loop for each row from a portal * * Used by exec_stmt_fors, exec_stmt_forc and exec_stmt_dynfors */ static int exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt, Portal portal, bool prefetch_ok) { PLpgSQL_rec *rec = NULL; PLpgSQL_row *row = NULL; SPITupleTable *tuptab; bool found = false; int rc = PLPGSQL_RC_OK; int n; /* * Determine if we assign to a record or a row */ if (stmt->rec != NULL) rec = (PLpgSQL_rec *) (estate->datums[stmt->rec->dno]); else if (stmt->row != NULL) row = (PLpgSQL_row *) (estate->datums[stmt->row->dno]); else elog(ERROR, "unsupported target"); /* * Fetch the initial tuple(s). If prefetching is allowed then we grab a * few more rows to avoid multiple trips through executor startup * overhead. */ SPI_cursor_fetch(portal, true, prefetch_ok ? 10 : 1); tuptab = SPI_tuptable; n = SPI_processed; /* * If the query didn't return any rows, set the target to NULL and fall * through with found = false. */ if (n <= 0) exec_move_row(estate, rec, row, NULL, tuptab->tupdesc); else found = true; /* processed at least one tuple */ /* * Now do the loop */ while (n > 0) { int i; for (i = 0; i < n; i++) { /* * Assign the tuple to the target */ exec_move_row(estate, rec, row, tuptab->vals[i], tuptab->tupdesc); /* * Execute the statements */ rc = exec_stmts(estate, stmt->body); if (rc != PLPGSQL_RC_OK) { if (rc == PLPGSQL_RC_EXIT) { if (estate->exitlabel == NULL) { /* unlabelled exit, so exit the current loop */ rc = PLPGSQL_RC_OK; } else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches this loop, so exit loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; } /* * 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. */ } else if (rc == PLPGSQL_RC_CONTINUE) { if (estate->exitlabel == NULL) { /* unlabelled continue, so re-run the current loop */ rc = PLPGSQL_RC_OK; continue; } else if (stmt->label != NULL && strcmp(stmt->label, estate->exitlabel) == 0) { /* label matches this loop, so re-run loop */ estate->exitlabel = NULL; rc = PLPGSQL_RC_OK; continue; } /* * otherwise, we process 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. Need a goto to get out of two * levels of loop... */ goto loop_exit; } } SPI_freetuptable(tuptab); /* * Fetch more tuples. If prefetching is allowed, grab 50 at a time. */ SPI_cursor_fetch(portal, true, prefetch_ok ? 50 : 1); tuptab = SPI_tuptable; n = SPI_processed; } loop_exit: /* * Release last group of tuples (if any) */ SPI_freetuptable(tuptab); /* * Set the FOUND variable to indicate the result of executing the loop * (namely, whether we looped one or more times). This must be set last so * that it does not interfere with the value of the FOUND variable inside * the loop processing itself. */ exec_set_found(estate, found); return rc; } /* ---------- * exec_eval_simple_expr - Evaluate a simple expression returning * a Datum by directly calling ExecEvalExpr(). * * If successful, store results into *result, *isNull, *rettype and return * TRUE. If the expression is not simple (any more), return FALSE. * * It is possible though unlikely for a simple expression to become non-simple * (consider for example redefining a trivial view). We must handle that for * correctness; fortunately it's normally inexpensive to do * RevalidateCachedPlan on a simple expression. We do not consider the other * direction (non-simple expression becoming simple) because we'll still give * correct results if that happens, and it's unlikely to be worth the cycles * to check. * * Note: if pass-by-reference, the result is in the eval_econtext's * temporary memory context. It will be freed when exec_eval_cleanup * is done. * ---------- */ static bool exec_eval_simple_expr(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, Datum *result, bool *isNull, Oid *rettype) { ExprContext *econtext = estate->eval_econtext; LocalTransactionId curlxid = MyProc->lxid; CachedPlanSource *plansource; CachedPlan *cplan; ParamListInfo paramLI; PLpgSQL_expr *save_cur_expr; MemoryContext oldcontext; /* * Forget it if expression wasn't simple before. */ if (expr->expr_simple_expr == NULL) return false; /* * Revalidate cached plan, so that we will notice if it became stale. (We * also need to hold a refcount while using the plan.) Note that even if * replanning occurs, the length of plancache_list can't change, since it * is a property of the raw parsetree generated from the query text. */ Assert(list_length(expr->plan->plancache_list) == 1); plansource = (CachedPlanSource *) linitial(expr->plan->plancache_list); cplan = RevalidateCachedPlan(plansource, true); if (cplan->generation != expr->expr_simple_generation) { /* It got replanned ... is it still simple? */ exec_simple_check_plan(expr); if (expr->expr_simple_expr == NULL) { /* Ooops, release refcount and fail */ ReleaseCachedPlan(cplan, true); return false; } } /* * Pass back previously-determined result type. */ *rettype = expr->expr_simple_type; /* * Prepare the expression for execution, if it's not been done already in * the current transaction. (This will be forced to happen if we called * exec_simple_check_plan above.) */ if (expr->expr_simple_lxid != curlxid) { expr->expr_simple_state = ExecPrepareExpr(expr->expr_simple_expr, simple_eval_estate); expr->expr_simple_lxid = curlxid; } /* * We have to do some of the things SPI_execute_plan would do, in * particular advance the snapshot if we are in a non-read-only function. * Without this, stable functions within the expression would fail to see * updates made so far by our own function. */ SPI_push(); oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory); if (!estate->readonly_func) { CommandCounterIncrement(); PushActiveSnapshot(GetTransactionSnapshot()); } /* * Create the param list in econtext's temporary memory context. * We won't need to free it explicitly, since it will go away at the * next reset of that context. * * XXX think about avoiding repeated palloc's for param lists? It should * be possible --- this routine isn't re-entrant anymore. * * Just for paranoia's sake, save and restore the prior value of * estate->cur_expr, which setup_param_list() sets. */ save_cur_expr = estate->cur_expr; paramLI = setup_param_list(estate, expr); econtext->ecxt_param_list_info = paramLI; /* * Finally we can call the executor to evaluate the expression */ *result = ExecEvalExpr(expr->expr_simple_state, econtext, isNull, NULL); /* Assorted cleanup */ estate->cur_expr = save_cur_expr; if (!estate->readonly_func) PopActiveSnapshot(); MemoryContextSwitchTo(oldcontext); SPI_pop(); /* * Now we can release our refcount on the cached plan. */ ReleaseCachedPlan(cplan, true); /* * That's it. */ return true; } /* * Create a ParamListInfo to pass to SPI * * The ParamListInfo array is initially all zeroes, in particular the * ptype values are all InvalidOid. This causes the executor to call the * paramFetch hook each time it wants a value. We thus evaluate only the * parameters actually demanded. * * The result is a locally palloc'd array that should be pfree'd after use; * but note it can be NULL. */ static ParamListInfo setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr) { ParamListInfo paramLI; /* * Could we re-use these arrays instead of palloc'ing a new one each * time? However, we'd have to zero the array each time anyway, * since new values might have been assigned to the variables. */ if (estate->ndatums > 0) { /* sizeof(ParamListInfoData) includes the first array element */ paramLI = (ParamListInfo) palloc0(sizeof(ParamListInfoData) + (estate->ndatums - 1) * sizeof(ParamExternData)); paramLI->paramFetch = plpgsql_param_fetch; paramLI->paramFetchArg = (void *) estate; paramLI->parserSetup = (ParserSetupHook) plpgsql_parser_setup; paramLI->parserSetupArg = (void *) expr; paramLI->numParams = estate->ndatums; /* * Set up link to active expr where the hook functions can find it. * Callers must save and restore cur_expr if there is any chance * that they are interrupting an active use of parameters. */ estate->cur_expr = expr; /* * Also make sure this is set before parser hooks need it. There * is no need to save and restore, since the value is always correct * once set. */ expr->func = estate->func; } else paramLI = NULL; return paramLI; } /* * plpgsql_param_fetch paramFetch callback for dynamic parameter fetch */ static void plpgsql_param_fetch(ParamListInfo params, int paramid) { int dno; PLpgSQL_execstate *estate; PLpgSQL_expr *expr; PLpgSQL_datum *datum; ParamExternData *prm; /* paramid's are 1-based, but dnos are 0-based */ dno = paramid - 1; Assert(dno >= 0 && dno < params->numParams); /* fetch back the hook data */ estate = (PLpgSQL_execstate *) params->paramFetchArg; expr = estate->cur_expr; Assert(params->numParams == estate->ndatums); /* * Do nothing if asked for a value that's not supposed to be used by * this SQL expression. This avoids unwanted evaluations when functions * such as copyParamList try to materialize all the values. */ if (!bms_is_member(dno, expr->paramnos)) return; /* OK, evaluate the value and store into the appropriate paramlist slot */ datum = estate->datums[dno]; prm = ¶ms->params[dno]; exec_eval_datum(estate, datum, &prm->ptype, &prm->value, &prm->isnull); } /* ---------- * exec_move_row Move one tuple's values into a record or row * ---------- */ static void exec_move_row(PLpgSQL_execstate *estate, PLpgSQL_rec *rec, PLpgSQL_row *row, HeapTuple tup, TupleDesc tupdesc) { /* * Record is simple - just copy the tuple and its descriptor into the * record variable */ if (rec != NULL) { /* * Copy input first, just in case it is pointing at variable's value */ if (HeapTupleIsValid(tup)) tup = heap_copytuple(tup); else if (tupdesc) { /* If we have a tupdesc but no data, form an all-nulls tuple */ bool *nulls; nulls = (bool *) palloc(tupdesc->natts * sizeof(bool)); memset(nulls, true, tupdesc->natts * sizeof(bool)); tup = heap_form_tuple(tupdesc, NULL, nulls); pfree(nulls); } if (tupdesc) tupdesc = CreateTupleDescCopy(tupdesc); /* Free the old value ... */ if (rec->freetup) { heap_freetuple(rec->tup); rec->freetup = false; } if (rec->freetupdesc) { FreeTupleDesc(rec->tupdesc); rec->freetupdesc = false; } /* ... and install the new */ if (HeapTupleIsValid(tup)) { rec->tup = tup; rec->freetup = true; } else rec->tup = NULL; if (tupdesc) { rec->tupdesc = tupdesc; rec->freetupdesc = true; } else rec->tupdesc = NULL; return; } /* * Row is a bit more complicated in that we assign the individual * attributes of the tuple to the variables the row points to. * * NOTE: this code used to demand row->nfields == * HeapTupleHeaderGetNatts(tup->t_data), but that's wrong. The tuple * might have more fields than we expected if it's from an * inheritance-child table of the current 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. * We also have to skip over dropped columns in either the source or * destination. * * If we have no tuple data at all, we'll assign NULL to all columns of * the row variable. */ if (row != NULL) { int td_natts = tupdesc ? tupdesc->natts : 0; int t_natts; int fnum; int anum; if (HeapTupleIsValid(tup)) t_natts = HeapTupleHeaderGetNatts(tup->t_data); else t_natts = 0; anum = 0; for (fnum = 0; fnum < row->nfields; fnum++) { PLpgSQL_var *var; Datum value; bool isnull; Oid valtype; if (row->varnos[fnum] < 0) continue; /* skip dropped column in row struct */ var = (PLpgSQL_var *) (estate->datums[row->varnos[fnum]]); while (anum < td_natts && tupdesc->attrs[anum]->attisdropped) anum++; /* skip dropped column in tuple */ if (anum < td_natts) { if (anum < t_natts) value = SPI_getbinval(tup, tupdesc, anum + 1, &isnull); else { value = (Datum) 0; isnull = true; } valtype = SPI_gettypeid(tupdesc, anum + 1); anum++; } else { value = (Datum) 0; isnull = true; valtype = InvalidOid; } exec_assign_value(estate, (PLpgSQL_datum *) var, value, valtype, &isnull); } return; } elog(ERROR, "unsupported target"); } /* ---------- * make_tuple_from_row Make a tuple from the values of a row object * * A NULL return indicates rowtype mismatch; caller must raise suitable error * ---------- */ static HeapTuple make_tuple_from_row(PLpgSQL_execstate *estate, PLpgSQL_row *row, TupleDesc tupdesc) { int natts = tupdesc->natts; HeapTuple tuple; Datum *dvalues; bool *nulls; int i; if (natts != row->nfields) return NULL; dvalues = (Datum *) palloc0(natts * sizeof(Datum)); nulls = (bool *) palloc(natts * sizeof(bool)); for (i = 0; i < natts; i++) { Oid fieldtypeid; if (tupdesc->attrs[i]->attisdropped) { nulls[i] = true; /* leave the column as null */ continue; } if (row->varnos[i] < 0) /* should not happen */ elog(ERROR, "dropped rowtype entry for non-dropped column"); exec_eval_datum(estate, estate->datums[row->varnos[i]], &fieldtypeid, &dvalues[i], &nulls[i]); if (fieldtypeid != tupdesc->attrs[i]->atttypid) return NULL; } tuple = heap_form_tuple(tupdesc, dvalues, nulls); pfree(dvalues); pfree(nulls); return tuple; } /* ---------- * convert_value_to_string Convert a non-null Datum to C string * * Note: callers generally assume that the result is a palloc'd string and * should be pfree'd. This is not all that safe an assumption ... * * Note: not caching the conversion function lookup is bad for performance. * ---------- */ static char * convert_value_to_string(Datum value, Oid valtype) { Oid typoutput; bool typIsVarlena; getTypeOutputInfo(valtype, &typoutput, &typIsVarlena); return OidOutputFunctionCall(typoutput, value); } /* ---------- * exec_cast_value Cast a value if required * ---------- */ static Datum exec_cast_value(Datum value, Oid valtype, Oid reqtype, FmgrInfo *reqinput, Oid reqtypioparam, int32 reqtypmod, bool isnull) { /* * If the type of the queries return value isn't that of the variable, * convert it. */ if (valtype != reqtype || reqtypmod != -1) { if (!isnull) { char *extval; extval = convert_value_to_string(value, valtype); value = InputFunctionCall(reqinput, extval, reqtypioparam, reqtypmod); pfree(extval); } else { value = InputFunctionCall(reqinput, NULL, reqtypioparam, reqtypmod); } } return value; } /* ---------- * exec_simple_cast_value Cast a value if required * * As above, but need not supply details about target type. Note that this * is slower than exec_cast_value with cached type info, and so should be * avoided in heavily used code paths. * ---------- */ static Datum exec_simple_cast_value(Datum value, Oid valtype, Oid reqtype, int32 reqtypmod, bool isnull) { if (valtype != reqtype || reqtypmod != -1) { Oid typinput; Oid typioparam; FmgrInfo finfo_input; getTypeInputInfo(reqtype, &typinput, &typioparam); fmgr_info(typinput, &finfo_input); value = exec_cast_value(value, valtype, reqtype, &finfo_input, typioparam, reqtypmod, isnull); } return value; } /* ---------- * exec_simple_check_node - Recursively check if an expression * is made only of simple things we can * hand out directly to ExecEvalExpr() * instead of calling SPI. * ---------- */ static bool exec_simple_check_node(Node *node) { if (node == NULL) return TRUE; switch (nodeTag(node)) { case T_Const: return TRUE; case T_Param: return TRUE; case T_ArrayRef: { ArrayRef *expr = (ArrayRef *) node; if (!exec_simple_check_node((Node *) expr->refupperindexpr)) return FALSE; if (!exec_simple_check_node((Node *) expr->reflowerindexpr)) return FALSE; if (!exec_simple_check_node((Node *) expr->refexpr)) return FALSE; if (!exec_simple_check_node((Node *) expr->refassgnexpr)) return FALSE; return TRUE; } case T_FuncExpr: { FuncExpr *expr = (FuncExpr *) node; if (expr->funcretset) return FALSE; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_OpExpr: { OpExpr *expr = (OpExpr *) node; if (expr->opretset) return FALSE; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_DistinctExpr: { DistinctExpr *expr = (DistinctExpr *) node; if (expr->opretset) return FALSE; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_ScalarArrayOpExpr: { ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_BoolExpr: { BoolExpr *expr = (BoolExpr *) node; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_FieldSelect: return exec_simple_check_node((Node *) ((FieldSelect *) node)->arg); case T_FieldStore: { FieldStore *expr = (FieldStore *) node; if (!exec_simple_check_node((Node *) expr->arg)) return FALSE; if (!exec_simple_check_node((Node *) expr->newvals)) return FALSE; return TRUE; } case T_RelabelType: return exec_simple_check_node((Node *) ((RelabelType *) node)->arg); case T_CoerceViaIO: return exec_simple_check_node((Node *) ((CoerceViaIO *) node)->arg); case T_ArrayCoerceExpr: return exec_simple_check_node((Node *) ((ArrayCoerceExpr *) node)->arg); case T_ConvertRowtypeExpr: return exec_simple_check_node((Node *) ((ConvertRowtypeExpr *) node)->arg); case T_CaseExpr: { CaseExpr *expr = (CaseExpr *) node; if (!exec_simple_check_node((Node *) expr->arg)) return FALSE; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; if (!exec_simple_check_node((Node *) expr->defresult)) return FALSE; return TRUE; } case T_CaseWhen: { CaseWhen *when = (CaseWhen *) node; if (!exec_simple_check_node((Node *) when->expr)) return FALSE; if (!exec_simple_check_node((Node *) when->result)) return FALSE; return TRUE; } case T_CaseTestExpr: return TRUE; case T_ArrayExpr: { ArrayExpr *expr = (ArrayExpr *) node; if (!exec_simple_check_node((Node *) expr->elements)) return FALSE; return TRUE; } case T_RowExpr: { RowExpr *expr = (RowExpr *) node; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_RowCompareExpr: { RowCompareExpr *expr = (RowCompareExpr *) node; if (!exec_simple_check_node((Node *) expr->largs)) return FALSE; if (!exec_simple_check_node((Node *) expr->rargs)) return FALSE; return TRUE; } case T_CoalesceExpr: { CoalesceExpr *expr = (CoalesceExpr *) node; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_MinMaxExpr: { MinMaxExpr *expr = (MinMaxExpr *) node; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_XmlExpr: { XmlExpr *expr = (XmlExpr *) node; if (!exec_simple_check_node((Node *) expr->named_args)) return FALSE; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_NullIfExpr: { NullIfExpr *expr = (NullIfExpr *) node; if (expr->opretset) return FALSE; if (!exec_simple_check_node((Node *) expr->args)) return FALSE; return TRUE; } case T_NullTest: return exec_simple_check_node((Node *) ((NullTest *) node)->arg); case T_BooleanTest: return exec_simple_check_node((Node *) ((BooleanTest *) node)->arg); case T_CoerceToDomain: return exec_simple_check_node((Node *) ((CoerceToDomain *) node)->arg); case T_CoerceToDomainValue: return TRUE; case T_List: { List *expr = (List *) node; ListCell *l; foreach(l, expr) { if (!exec_simple_check_node(lfirst(l))) return FALSE; } return TRUE; } default: return FALSE; } } /* ---------- * exec_simple_check_plan - Check if a plan is simple enough to * be evaluated by ExecEvalExpr() instead * of SPI. * ---------- */ static void exec_simple_check_plan(PLpgSQL_expr *expr) { CachedPlanSource *plansource; PlannedStmt *stmt; Plan *plan; TargetEntry *tle; /* * Initialize to "not simple", and remember the plan generation number we * last checked. (If the query produces more or less than one parsetree * we just leave expr_simple_generation set to 0.) */ expr->expr_simple_expr = NULL; expr->expr_simple_generation = 0; /* * 1. We can only evaluate queries that resulted in one single execution * plan */ if (list_length(expr->plan->plancache_list) != 1) return; plansource = (CachedPlanSource *) linitial(expr->plan->plancache_list); expr->expr_simple_generation = plansource->generation; if (list_length(plansource->plan->stmt_list) != 1) return; stmt = (PlannedStmt *) linitial(plansource->plan->stmt_list); /* * 2. It must be a RESULT plan --> no scan's required */ if (!IsA(stmt, PlannedStmt)) return; plan = stmt->planTree; if (!IsA(plan, Result)) return; /* * 3. Can't have any subplan or qual clause, either */ if (plan->lefttree != NULL || plan->righttree != NULL || plan->initPlan != NULL || plan->qual != NULL || ((Result *) plan)->resconstantqual != NULL) return; /* * 4. The plan must have a single attribute as result */ if (list_length(plan->targetlist) != 1) return; tle = (TargetEntry *) linitial(plan->targetlist); /* * 5. Check that all the nodes in the expression are non-scary. */ if (!exec_simple_check_node((Node *) tle->expr)) return; /* * Yes - this is a simple expression. Mark it as such, and initialize * state to "not valid in current transaction". */ expr->expr_simple_expr = tle->expr; expr->expr_simple_state = NULL; expr->expr_simple_lxid = InvalidLocalTransactionId; /* Also stash away the expression result type */ expr->expr_simple_type = exprType((Node *) tle->expr); } /* ---------- * exec_set_found Set the global found variable * to true/false * ---------- */ static void exec_set_found(PLpgSQL_execstate *estate, bool state) { PLpgSQL_var *var; var = (PLpgSQL_var *) (estate->datums[estate->found_varno]); var->value = PointerGetDatum(state); var->isnull = false; } /* * plpgsql_create_econtext --- create an eval_econtext for the current function * * We may need to create a new simple_eval_estate too, if there's not one * already for the current transaction. The EState will be cleaned up at * transaction end. */ static void plpgsql_create_econtext(PLpgSQL_execstate *estate) { SimpleEcontextStackEntry *entry; /* * Create an EState for evaluation of simple expressions, if there's not * one already in the current transaction. The EState is made a child of * TopTransactionContext so it will have the right lifespan. */ if (simple_eval_estate == NULL) { MemoryContext oldcontext; oldcontext = MemoryContextSwitchTo(TopTransactionContext); simple_eval_estate = CreateExecutorState(); MemoryContextSwitchTo(oldcontext); } /* * Create a child econtext for the current function. */ estate->eval_econtext = CreateExprContext(simple_eval_estate); /* * Make a stack entry so we can clean up the econtext at subxact end. * Stack entries are kept in TopTransactionContext for simplicity. */ entry = (SimpleEcontextStackEntry *) MemoryContextAlloc(TopTransactionContext, sizeof(SimpleEcontextStackEntry)); entry->stack_econtext = estate->eval_econtext; entry->xact_subxid = GetCurrentSubTransactionId(); entry->next = simple_econtext_stack; simple_econtext_stack = entry; } /* * plpgsql_destroy_econtext --- destroy function's econtext * * We check that it matches the top stack entry, and destroy the stack * entry along with the context. */ static void plpgsql_destroy_econtext(PLpgSQL_execstate *estate) { SimpleEcontextStackEntry *next; Assert(simple_econtext_stack != NULL); Assert(simple_econtext_stack->stack_econtext == estate->eval_econtext); next = simple_econtext_stack->next; pfree(simple_econtext_stack); simple_econtext_stack = next; FreeExprContext(estate->eval_econtext, true); estate->eval_econtext = NULL; } /* * plpgsql_xact_cb --- post-transaction-commit-or-abort cleanup * * If a simple-expression EState was created in the current transaction, * it has to be cleaned up. */ void plpgsql_xact_cb(XactEvent event, void *arg) { /* * If we are doing a clean transaction shutdown, free the EState (so that * any remaining resources will be released correctly). In an abort, we * expect the regular abort recovery procedures to release everything of * interest. */ if (event != XACT_EVENT_ABORT) { /* Shouldn't be any econtext stack entries left at commit */ Assert(simple_econtext_stack == NULL); if (simple_eval_estate) FreeExecutorState(simple_eval_estate); simple_eval_estate = NULL; } else { simple_econtext_stack = NULL; simple_eval_estate = NULL; } } /* * plpgsql_subxact_cb --- post-subtransaction-commit-or-abort cleanup * * Make sure any simple-expression econtexts created in the current * subtransaction get cleaned up. We have to do this explicitly because * no other code knows which child econtexts of simple_eval_estate belong * to which level of subxact. */ void plpgsql_subxact_cb(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg) { if (event == SUBXACT_EVENT_START_SUB) return; while (simple_econtext_stack != NULL && simple_econtext_stack->xact_subxid == mySubid) { SimpleEcontextStackEntry *next; FreeExprContext(simple_econtext_stack->stack_econtext, (event == SUBXACT_EVENT_COMMIT_SUB)); next = simple_econtext_stack->next; pfree(simple_econtext_stack); simple_econtext_stack = next; } } /* * free_var --- pfree any pass-by-reference value of the variable. * * This should always be followed by some assignment to var->value, * as it leaves a dangling pointer. */ static void free_var(PLpgSQL_var *var) { if (var->freeval) { pfree(DatumGetPointer(var->value)); var->freeval = false; } } /* * free old value of a text variable and assign new value from C string */ static void assign_text_var(PLpgSQL_var *var, const char *str) { free_var(var); var->value = CStringGetTextDatum(str); var->isnull = false; var->freeval = true; } /* * exec_eval_using_params --- evaluate params of USING clause */ static PreparedParamsData * exec_eval_using_params(PLpgSQL_execstate *estate, List *params) { PreparedParamsData *ppd; int nargs; int i; ListCell *lc; ppd = (PreparedParamsData *) palloc(sizeof(PreparedParamsData)); nargs = list_length(params); ppd->nargs = nargs; ppd->types = (Oid *) palloc(nargs * sizeof(Oid)); ppd->values = (Datum *) palloc(nargs * sizeof(Datum)); ppd->nulls = (char *) palloc(nargs * sizeof(char)); ppd->freevals = (bool *) palloc(nargs * sizeof(bool)); i = 0; foreach(lc, params) { PLpgSQL_expr *param = (PLpgSQL_expr *) lfirst(lc); bool isnull; ppd->values[i] = exec_eval_expr(estate, param, &isnull, &ppd->types[i]); ppd->nulls[i] = isnull ? 'n' : ' '; ppd->freevals[i] = false; /* pass-by-ref non null values must be copied into plpgsql context */ if (!isnull) { int16 typLen; bool typByVal; get_typlenbyval(ppd->types[i], &typLen, &typByVal); if (!typByVal) { ppd->values[i] = datumCopy(ppd->values[i], typByVal, typLen); ppd->freevals[i] = true; } } exec_eval_cleanup(estate); i++; } return ppd; } /* * free_params_data --- pfree all pass-by-reference values used in USING clause */ static void free_params_data(PreparedParamsData *ppd) { int i; for (i = 0; i < ppd->nargs; i++) { if (ppd->freevals[i]) pfree(DatumGetPointer(ppd->values[i])); } pfree(ppd->types); pfree(ppd->values); pfree(ppd->nulls); pfree(ppd->freevals); pfree(ppd); } /* * Open portal for dynamic query */ static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate, PLpgSQL_expr *dynquery, List *params) { Portal portal; Datum query; bool isnull; Oid restype; char *querystr; /* * Evaluate the string expression after the EXECUTE keyword. Its result is * the querystring we have to execute. */ query = exec_eval_expr(estate, dynquery, &isnull, &restype); if (isnull) ereport(ERROR, (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("query string argument of EXECUTE is null"))); /* Get the C-String representation */ querystr = convert_value_to_string(query, restype); exec_eval_cleanup(estate); /* * Open an implicit cursor for the query. We use * SPI_cursor_open_with_args even when there are no params, because this * avoids making and freeing one copy of the plan. */ if (params) { PreparedParamsData *ppd; ppd = exec_eval_using_params(estate, params); portal = SPI_cursor_open_with_args(NULL, querystr, ppd->nargs, ppd->types, ppd->values, ppd->nulls, estate->readonly_func, 0); free_params_data(ppd); } else { portal = SPI_cursor_open_with_args(NULL, querystr, 0, NULL, NULL, NULL, estate->readonly_func, 0); } if (portal == NULL) elog(ERROR, "could not open implicit cursor for query \"%s\": %s", querystr, SPI_result_code_string(SPI_result)); pfree(querystr); return portal; }