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postgres/src/pl/plpgsql/src/pl_exec.c

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/*-------------------------------------------------------------------------
*
* pl_exec.c - Executor for the PL/pgSQL
* procedural language
*
* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/pl/plpgsql/src/pl_exec.c
*
*-------------------------------------------------------------------------
*/
#include "plpgsql.h"
#include <ctype.h>
#include "access/htup_details.h"
#include "access/transam.h"
#include "access/tupconvert.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "executor/spi.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/rel.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.)
*
* However, there's no value in trying to amortize simple expression setup
* across multiple executions of a DO block (inline code block), since there
* can never be any. If we use the shared EState for a DO block, the expr
* state trees are effectively leaked till end of transaction, and that can
* add up if the user keeps on submitting DO blocks. Therefore, each DO block
* has its own simple-expression EState, which is cleaned up at exit from
* plpgsql_inline_handler(). DO blocks still use the simple_econtext_stack,
* though, so that subxact abort cleanup does the right thing.
*/
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 *shared_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_foreach_a(PLpgSQL_execstate *estate,
PLpgSQL_stmt_foreach_a *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,
EState *simple_eval_estate);
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 void exec_simple_recheck_plan(PLpgSQL_expr *expr, CachedPlan *cplan);
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_c_string(PLpgSQL_execstate *estate,
PLpgSQL_datum *target,
const char *str);
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,
int32 *typetypmod,
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 HeapTuple get_tuple_from_datum(Datum value);
static TupleDesc get_tupdesc_from_datum(Datum value);
static void exec_move_row_from_datum(PLpgSQL_execstate *estate,
PLpgSQL_rec *rec,
PLpgSQL_row *row,
Datum value);
static char *convert_value_to_string(PLpgSQL_execstate *estate,
Datum value, Oid valtype);
static Datum exec_cast_value(PLpgSQL_execstate *estate,
Datum value, Oid valtype,
Oid reqtype,
FmgrInfo *reqinput,
Oid reqtypioparam,
int32 reqtypmod,
bool isnull);
static Datum exec_simple_cast_value(PLpgSQL_execstate *estate,
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 *dynquery, List *params,
const char *portalname, int cursorOptions);
static char *format_expr_params(PLpgSQL_execstate *estate,
const PLpgSQL_expr *expr);
static char *format_preparedparamsdata(PLpgSQL_execstate *estate,
const PreparedParamsData *ppd);
/* ----------
* plpgsql_exec_function Called by the call handler for
* function execution.
*
* This is also used to execute inline code blocks (DO blocks). The only
* difference that this code is aware of is that for a DO block, we want
* to use a private simple_eval_estate, which is created and passed in by
* the caller. For regular functions, pass NULL, which implies using
* shared_simple_eval_estate.
* ----------
*/
Datum
plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo,
EState *simple_eval_estate)
{
PLpgSQL_execstate estate;
ErrorContextCallback plerrcontext;
int i;
int rc;
/*
* Setup the execution state
*/
plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo,
simple_eval_estate);
/*
* 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])
{
/* Assign row value from composite datum */
exec_move_row_from_datum(&estate, NULL, row,
fcinfo->arg[i]);
}
else
{
/* If arg is null, treat it as an empty row */
exec_move_row(&estate, NULL, row, NULL, NULL);
}
/* clean up after exec_move_row() */
exec_eval_cleanup(&estate);
}
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
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,
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, 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_ROW(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 if (TRIGGER_FIRED_INSTEAD(trigdata->tg_event))
var->value = CStringGetTextDatum("INSTEAD OF");
else
elog(ERROR, "unrecognized trigger execution time: not BEFORE, AFTER, or INSTEAD OF");
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
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_ROW(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;
}
void
plpgsql_exec_event_trigger(PLpgSQL_function *func, EventTriggerData *trigdata)
{
PLpgSQL_execstate estate;
ErrorContextCallback plerrcontext;
int i;
int rc;
PLpgSQL_var *var;
/*
* Setup the execution state
*/
plpgsql_estate_setup(&estate, func, NULL, 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]);
/*
* Assign the special tg_ variables
*/
var = (PLpgSQL_var *) (estate.datums[func->tg_event_varno]);
var->value = CStringGetTextDatum(trigdata->event);
var->isnull = false;
var->freeval = true;
var = (PLpgSQL_var *) (estate.datums[func->tg_tag_varno]);
var->value = CStringGetTextDatum(trigdata->tag);
var->isnull = false;
var->freeval = true;
/*
* 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
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");
/*
* 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;
}
/*
* 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_signature,
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_signature,
_(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_signature,
estate->err_stmt->lineno,
plpgsql_stmt_typename(estate->err_stmt));
}
else
errcontext("PL/pgSQL function %s",
estate->func->fn_signature);
}
/* ----------
* 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 (well, ARRAYELEM contains some cached type data, but
* we'd just as soon centralize the caching anyway)
*/
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;
ErrorData *save_cur_error = estate->cur_error;
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();
/*
* Must clean up the econtext too. However, any tuple table made
* in the subxact will have been thrown away by SPI during subxact
* abort, so we don't need to (and mustn't try to) free the
* eval_tuptable.
*/
estate->eval_tuptable = NULL;
exec_eval_cleanup(estate);
/* 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; this also frees values from any
* prior use of the same exception. 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);
/*
* Also set up cur_error so the error data is accessible
* inside the handler.
*/
estate->cur_error = edata;
estate->err_text = NULL;
rc = exec_stmts(estate, exception->action);
break;
}
}
/*
* Restore previous state of cur_error, whether or not we executed
* a handler. This is needed in case an error got thrown from
* some inner block's exception handler.
*/
estate->cur_error = save_cur_error;
/* If no match found, re-throw the error */
if (e == NULL)
ReThrowError(edata);
else
FreeErrorData(edata);
}
PG_END_TRY();
Assert(save_cur_error == estate->cur_error);
}
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:
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_FOREACH_A:
rc = exec_stmt_foreach_a(estate, (PLpgSQL_stmt_foreach_a *) 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;
/*
* GET STACKED DIAGNOSTICS is only valid inside an exception handler.
*
* Note: we trust the grammar to have disallowed the relevant item kinds
* if not is_stacked, otherwise we'd dump core below.
*/
if (stmt->is_stacked && estate->cur_error == NULL)
ereport(ERROR,
(errcode(ERRCODE_STACKED_DIAGNOSTICS_ACCESSED_WITHOUT_ACTIVE_HANDLER),
errmsg("GET STACKED DIAGNOSTICS cannot be used outside an exception handler")));
foreach(lc, stmt->diag_items)
{
PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc);
PLpgSQL_datum *var = estate->datums[diag_item->target];
bool isnull = false;
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;
case PLPGSQL_GETDIAG_ERROR_CONTEXT:
exec_assign_c_string(estate, var,
estate->cur_error->context);
break;
case PLPGSQL_GETDIAG_ERROR_DETAIL:
exec_assign_c_string(estate, var,
estate->cur_error->detail);
break;
case PLPGSQL_GETDIAG_ERROR_HINT:
exec_assign_c_string(estate, var,
estate->cur_error->hint);
break;
case PLPGSQL_GETDIAG_RETURNED_SQLSTATE:
exec_assign_c_string(estate, var,
unpack_sql_state(estate->cur_error->sqlerrcode));
break;
case PLPGSQL_GETDIAG_COLUMN_NAME:
exec_assign_c_string(estate, var,
estate->cur_error->column_name);
break;
case PLPGSQL_GETDIAG_CONSTRAINT_NAME:
exec_assign_c_string(estate, var,
estate->cur_error->constraint_name);
break;
case PLPGSQL_GETDIAG_DATATYPE_NAME:
exec_assign_c_string(estate, var,
estate->cur_error->datatype_name);
break;
case PLPGSQL_GETDIAG_MESSAGE_TEXT:
exec_assign_c_string(estate, var,
estate->cur_error->message);
break;
case PLPGSQL_GETDIAG_TABLE_NAME:
exec_assign_c_string(estate, var,
estate->cur_error->table_name);
break;
case PLPGSQL_GETDIAG_SCHEMA_NAME:
exec_assign_c_string(estate, var,
estate->cur_error->schema_name);
break;
case PLPGSQL_GETDIAG_CONTEXT:
{
char *contextstackstr = GetErrorContextStack();
exec_assign_c_string(estate, var, contextstackstr);
pfree(contextstackstr);
}
break;
default:
elog(ERROR, "unrecognized diagnostic item kind: %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;
ListCell *lc;
value = exec_eval_boolean(estate, stmt->cond, &isnull);
exec_eval_cleanup(estate);
if (!isnull && value)
return exec_stmts(estate, stmt->then_body);
foreach(lc, stmt->elsif_list)
{
PLpgSQL_if_elsif *elif = (PLpgSQL_if_elsif *) lfirst(lc);
value = exec_eval_boolean(estate, elif->cond, &isnull);
exec_eval_cleanup(estate);
if (!isnull && value)
return exec_stmts(estate, elif->stmts);
}
return exec_stmts(estate, stmt->else_body);
}
/*-----------
* 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,
estate->func->fn_input_collation);
/* 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:
return rc;
default:
elog(ERROR, "unrecognized rc: %d", rc);
}
}
}
/* ----------
* 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:
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(estate, 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(estate, 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(estate, 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)
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 (hook function and possibly data values)
*/
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_foreach_a Loop over elements or slices of an array
*
* When looping over elements, the loop variable is the same type that the
* array stores (eg: integer), when looping through slices, the loop variable
* is an array of size and dimensions to match the size of the slice.
* ----------
*/
static int
exec_stmt_foreach_a(PLpgSQL_execstate *estate, PLpgSQL_stmt_foreach_a *stmt)
{
ArrayType *arr;
Oid arrtype;
PLpgSQL_datum *loop_var;
Oid loop_var_elem_type;
bool found = false;
int rc = PLPGSQL_RC_OK;
ArrayIterator array_iterator;
Oid iterator_result_type;
Datum value;
bool isnull;
/* get the value of the array expression */
value = exec_eval_expr(estate, stmt->expr, &isnull, &arrtype);
if (isnull)
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("FOREACH expression must not be null")));
/* check the type of the expression - must be an array */
if (!OidIsValid(get_element_type(arrtype)))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("FOREACH expression must yield an array, not type %s",
format_type_be(arrtype))));
/*
* We must copy the array, else it will disappear in exec_eval_cleanup.
* This is annoying, but cleanup will certainly happen while running the
* loop body, so we have little choice.
*/
arr = DatumGetArrayTypePCopy(value);
/* Clean up any leftover temporary memory */
exec_eval_cleanup(estate);
/* Slice dimension must be less than or equal to array dimension */
if (stmt->slice < 0 || stmt->slice > ARR_NDIM(arr))
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("slice dimension (%d) is out of the valid range 0..%d",
stmt->slice, ARR_NDIM(arr))));
/* Set up the loop variable and see if it is of an array type */
loop_var = estate->datums[stmt->varno];
if (loop_var->dtype == PLPGSQL_DTYPE_REC ||
loop_var->dtype == PLPGSQL_DTYPE_ROW)
{
/*
* Record/row variable is certainly not of array type, and might not
* be initialized at all yet, so don't try to get its type
*/
loop_var_elem_type = InvalidOid;
}
else
loop_var_elem_type = get_element_type(exec_get_datum_type(estate,
loop_var));
/*
* Sanity-check the loop variable type. We don't try very hard here, and
* should not be too picky since it's possible that exec_assign_value can
* coerce values of different types. But it seems worthwhile to complain
* if the array-ness of the loop variable is not right.
*/
if (stmt->slice > 0 && loop_var_elem_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("FOREACH ... SLICE loop variable must be of an array type")));
if (stmt->slice == 0 && loop_var_elem_type != InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("FOREACH loop variable must not be of an array type")));
/* Create an iterator to step through the array */
array_iterator = array_create_iterator(arr, stmt->slice);
/* Identify iterator result type */
if (stmt->slice > 0)
{
/* When slicing, nominal type of result is same as array type */
iterator_result_type = arrtype;
}
else
{
/* Without slicing, results are individual array elements */
iterator_result_type = ARR_ELEMTYPE(arr);
}
/* Iterate over the array elements or slices */
while (array_iterate(array_iterator, &value, &isnull))
{
found = true; /* looped at least once */
/* Assign current element/slice to the loop variable */
exec_assign_value(estate, loop_var, value, iterator_result_type,
&isnull);
/* In slice case, value is temporary; must free it to avoid leakage */
if (stmt->slice > 0)
pfree(DatumGetPointer(value));
/*
* Execute the statements
*/
rc = exec_stmts(estate, stmt->body);
/* Handle the return code */
if (rc == PLPGSQL_RC_RETURN)
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;
}
}
}
/* Release temporary memory, including the array value */
array_free_iterator(array_iterator);
pfree(arr);
/*
* 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_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;
/*
* Special case path when the RETURN expression is a simple variable
* reference; in particular, this path is always taken in functions with
* one or more OUT parameters.
*/
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)
{
estate->retval = exec_eval_expr(estate, stmt->expr,
&(estate->retisnull),
&(estate->rettype));
if (estate->retistuple && !estate->retisnull)
{
/* Convert composite datum to a HeapTuple and TupleDesc */
HeapTuple tuple;
TupleDesc tupdesc;
/* Source must be of RECORD or composite type */
if (!type_is_rowtype(estate->rettype))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("cannot return non-composite value from function returning composite type")));
tuple = get_tuple_from_datum(estate->retval);
tupdesc = get_tupdesc_from_datum(estate->retval);
estate->retval = PointerGetDatum(tuple);
estate->rettupdesc = CreateTupleDescCopy(tupdesc);
ReleaseTupleDesc(tupdesc);
}
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.
*/
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;
/*
* Special case path when the RETURN NEXT expression is a simple variable
* reference; in particular, this path is always taken in functions with
* one or more OUT parameters.
*/
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(estate,
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);
free_tuple = true;
}
}
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;
retval = exec_eval_expr(estate,
stmt->expr,
&isNull,
&rettype);
if (estate->retistuple)
{
/* Expression should be of RECORD or composite type */
if (!isNull)
{
TupleDesc retvaldesc;
TupleConversionMap *tupmap;
if (!type_is_rowtype(rettype))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("cannot return non-composite value from function returning composite type")));
tuple = get_tuple_from_datum(retval);
free_tuple = true; /* tuple is always freshly palloc'd */
/* it might need conversion */
retvaldesc = get_tupdesc_from_datum(retval);
tupmap = convert_tuples_by_position(retvaldesc, tupdesc,
gettext_noop("returned record type does not match expected record type"));
if (tupmap)
{
HeapTuple newtuple;
newtuple = do_convert_tuple(tuple, tupmap);
free_conversion_map(tupmap);
heap_freetuple(tuple);
tuple = newtuple;
}
ReleaseTupleDesc(retvaldesc);
/* tuple will be stored into tuplestore below */
}
else
{
/* Composite NULL --- store a row of nulls */
Datum *nulldatums;
bool *nullflags;
nulldatums = (Datum *) palloc0(natts * sizeof(Datum));
nullflags = (bool *) palloc(natts * sizeof(bool));
memset(nullflags, true, natts * sizeof(bool));
tuplestore_putvalues(estate->tuple_store, tupdesc,
nulldatums, nullflags);
pfree(nulldatums);
pfree(nullflags);
}
}
else
{
/* Simple scalar result */
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(estate,
retval,
rettype,
tupdesc->attrs[0]->atttypid,
tupdesc->attrs[0]->atttypmod,
isNull);
tuplestore_putvalues(estate->tuple_store, tupdesc,
&retval, &isNull);
}
}
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);
}
exec_eval_cleanup(estate);
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, NULL, 0);
}
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;
}
#define SET_RAISE_OPTION_TEXT(opt, name) \
do { \
if (opt) \
ereport(ERROR, \
(errcode(ERRCODE_SYNTAX_ERROR), \
errmsg("RAISE option already specified: %s", \
name))); \
opt = pstrdup(extval); \
} while (0)
/* ----------
* 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;
char *err_column = NULL;
char *err_constraint = NULL;
char *err_datatype = NULL;
char *err_table = NULL;
char *err_schema = NULL;
ListCell *lc;
/* RAISE with no parameters: re-throw current exception */
if (stmt->condname == NULL && stmt->message == NULL &&
stmt->options == NIL)
{
if (estate->cur_error != NULL)
ReThrowError(estate->cur_error);
/* oops, we're not inside a handler */
ereport(ERROR,
(errcode(ERRCODE_STACKED_DIAGNOSTICS_ACCESSED_WITHOUT_ACTIVE_HANDLER),
errmsg("RAISE without parameters cannot be used outside an exception handler")));
}
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;
}
/* should have been checked at compile time */
if (current_param == NULL)
elog(ERROR, "unexpected RAISE parameter list length");
paramvalue = exec_eval_expr(estate,
(PLpgSQL_expr *) lfirst(current_param),
&paramisnull,
&paramtypeid);
if (paramisnull)
extval = "<NULL>";
else
extval = convert_value_to_string(estate,
paramvalue,
paramtypeid);
appendStringInfoString(&ds, extval);
current_param = lnext(current_param);
exec_eval_cleanup(estate);
}
else
appendStringInfoChar(&ds, cp[0]);
}
/* should have been checked at compile time */
if (current_param != NULL)
elog(ERROR, "unexpected RAISE parameter list length");
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(estate, 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:
SET_RAISE_OPTION_TEXT(err_message, "MESSAGE");
break;
case PLPGSQL_RAISEOPTION_DETAIL:
SET_RAISE_OPTION_TEXT(err_detail, "DETAIL");
break;
case PLPGSQL_RAISEOPTION_HINT:
SET_RAISE_OPTION_TEXT(err_hint, "HINT");
break;
case PLPGSQL_RAISEOPTION_COLUMN:
SET_RAISE_OPTION_TEXT(err_column, "COLUMN");
break;
case PLPGSQL_RAISEOPTION_CONSTRAINT:
SET_RAISE_OPTION_TEXT(err_constraint, "CONSTRAINT");
break;
case PLPGSQL_RAISEOPTION_DATATYPE:
SET_RAISE_OPTION_TEXT(err_datatype, "DATATYPE");
break;
case PLPGSQL_RAISEOPTION_TABLE:
SET_RAISE_OPTION_TEXT(err_table, "TABLE");
break;
case PLPGSQL_RAISEOPTION_SCHEMA:
SET_RAISE_OPTION_TEXT(err_schema, "SCHEMA");
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_internal("%s", err_detail) : 0,
(err_hint != NULL) ? errhint("%s", err_hint) : 0,
(err_column != NULL) ?
err_generic_string(PG_DIAG_COLUMN_NAME, err_column) : 0,
(err_constraint != NULL) ?
err_generic_string(PG_DIAG_CONSTRAINT_NAME, err_constraint) : 0,
(err_datatype != NULL) ?
err_generic_string(PG_DIAG_DATATYPE_NAME, err_datatype) : 0,
(err_table != NULL) ?
err_generic_string(PG_DIAG_TABLE_NAME, err_table) : 0,
(err_schema != NULL) ?
err_generic_string(PG_DIAG_SCHEMA_NAME, err_schema) : 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);
if (err_column != NULL)
pfree(err_column);
if (err_constraint != NULL)
pfree(err_constraint);
if (err_datatype != NULL)
pfree(err_datatype);
if (err_table != NULL)
pfree(err_table);
if (err_schema != NULL)
pfree(err_schema);
return PLPGSQL_RC_OK;
}
/* ----------
* Initialize a mostly empty execution state
* ----------
*/
static void
plpgsql_estate_setup(PLpgSQL_execstate *estate,
PLpgSQL_function *func,
ReturnSetInfo *rsi,
EState *simple_eval_estate)
{
/* 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->cur_error = 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 */
/* set up for use of appropriate simple-expression EState */
if (simple_eval_estate)
estate->simple_eval_estate = simple_eval_estate;
else
estate->simple_eval_estate = shared_simple_eval_estate;
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.
*
* NB: if you change this code, see also the hacks in exec_assign_value's
* PLPGSQL_DTYPE_ARRAYELEM case.
* ----------
*/
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));
}
}
SPI_keepplan(plan);
expr->plan = plan;
/* Check to see if it's a simple expression */
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, SPI_plan_get_plan_sources(expr->plan))
{
CachedPlanSource *plansource = (CachedPlanSource *) lfirst(l);
ListCell *l2;
foreach(l2, plansource->query_list)
{
Query *q = (Query *) lfirst(l2);
Assert(IsA(q, Query));
if (q->canSetTag)
{
if (q->commandType == CMD_INSERT ||
q->commandType == CMD_UPDATE ||
q->commandType == CMD_DELETE)
stmt->mod_stmt = true;
}
}
}
}
/*
* Set up ParamListInfo (hook function and possibly data values)
*/
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;
/* 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_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)
{
char *errdetail;
if (estate->func->print_strict_params)
errdetail = format_expr_params(estate, expr);
else
errdetail = NULL;
ereport(ERROR,
(errcode(ERRCODE_NO_DATA_FOUND),
errmsg("query returned no rows"),
errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
}
/* set the target to NULL(s) */
exec_move_row(estate, rec, row, NULL, tuptab->tupdesc);
}
else
{
if (n > 1 && (stmt->strict || stmt->mod_stmt))
{
char *errdetail;
if (estate->func->print_strict_params)
errdetail = format_expr_params(estate, expr);
else
errdetail = NULL;
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ROWS),
errmsg("query returned more than one row"),
errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
}
/* Put the first result row into the target */
exec_move_row(estate, rec, row, tuptab->vals[0], tuptab->tupdesc);
}
/* Clean up */
exec_eval_cleanup(estate);
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;
PreparedParamsData *ppd = NULL;
/*
* 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(estate, query, restype);
/* copy it out of the temporary context before we clean up */
querystr = pstrdup(querystr);
exec_eval_cleanup(estate);
/*
* Execute the query without preparing a saved plan.
*/
if (stmt->params)
{
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);
}
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.) This is not
* a functional limitation because CREATE TABLE AS is allowed.
*/
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("EXECUTE of SELECT ... INTO is not implemented"),
errhint("You might want to use EXECUTE ... INTO or EXECUTE CREATE TABLE ... AS instead.")));
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)
{
char *errdetail;
if (estate->func->print_strict_params)
errdetail = format_preparedparamsdata(estate, ppd);
else
errdetail = NULL;
ereport(ERROR,
(errcode(ERRCODE_NO_DATA_FOUND),
errmsg("query returned no rows"),
errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
}
/* set the target to NULL(s) */
exec_move_row(estate, rec, row, NULL, tuptab->tupdesc);
}
else
{
if (n > 1 && stmt->strict)
{
char *errdetail;
if (estate->func->print_strict_params)
errdetail = format_preparedparamsdata(estate, ppd);
else
errdetail = NULL;
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ROWS),
errmsg("query returned more than one row"),
errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
}
/* Put the first result row into the target */
exec_move_row(estate, rec, row, tuptab->vals[0], tuptab->tupdesc);
}
/* clean up after exec_move_row() */
exec_eval_cleanup(estate);
}
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.
*/
}
if (ppd)
free_params_data(ppd);
/* 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,
NULL, 0);
/*
* 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;
/* ----------
* 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 ...
* ----------
*/
portal = exec_dynquery_with_params(estate,
stmt->dynquery,
stmt->params,
curname,
stmt->cursor_options);
/*
* 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 (hook function and possibly data values)
*/
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);
exec_eval_cleanup(estate);
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_c_string Put a C string into a text variable.
*
* We take a NULL pointer as signifying empty string, not SQL null.
* ----------
*/
static void
exec_assign_c_string(PLpgSQL_execstate *estate, PLpgSQL_datum *target,
const char *str)
{
text *value;
bool isnull = false;
if (str != NULL)
value = cstring_to_text(str);
else
value = cstring_to_text("");
exec_assign_value(estate, target, PointerGetDatum(value),
TEXTOID, &isnull);
pfree(value);
}
/* ----------
* exec_assign_value Put a value into a target field
*
* Note: in some code paths, this will leak memory in the eval_econtext;
* we assume that will be cleaned up later by exec_eval_cleanup. We cannot
* call exec_eval_cleanup here for fear of destroying the input Datum value.
* ----------
*/
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(estate,
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, copy the new value (which is
* probably in the eval_econtext) into the procedure's memory
* context.
*/
if (!var->datatype->typbyval && !*isNull)
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;
if (*isNull)
{
/* If source is null, just assign nulls to the row */
exec_move_row(estate, NULL, row, NULL, NULL);
}
else
{
/* 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")));
exec_move_row_from_datum(estate, NULL, row, value);
}
break;
}
case PLPGSQL_DTYPE_REC:
{
/*
* Target is a record variable
*/
PLpgSQL_rec *rec = (PLpgSQL_rec *) target;
if (*isNull)
{
/* If source is null, just assign nulls to the record */
exec_move_row(estate, rec, NULL, NULL, NULL);
}
else
{
/* 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")));
exec_move_row_from_datum(estate, rec, NULL, value);
}
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;
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(estate,
value,
valtype,
atttype,
atttypmod,
attisnull);
nulls[fno] = attisnull;
/*
* 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);
break;
}
case PLPGSQL_DTYPE_ARRAYELEM:
{
/*
* Target is an element of an array
*/
PLpgSQL_arrayelem *arrayelem;
int nsubscripts;
int i;
PLpgSQL_expr *subscripts[MAXDIM];
int subscriptvals[MAXDIM];
Datum oldarraydatum,
newarraydatum,
coerced_value;
bool oldarrayisnull;
Oid parenttypoid;
int32 parenttypmod;
SPITupleTable *save_eval_tuptable;
MemoryContext oldcontext;
/*
* We need to do subscript evaluation, which might require
* evaluating general expressions; and the caller might have
* done that too in order to prepare the input Datum. We have
* to save and restore the caller's SPI_execute result, if
* any.
*/
save_eval_tuptable = estate->eval_tuptable;
estate->eval_tuptable = NULL;
/*
* 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.) Note that arrayelem is left pointing
* to the leftmost arrayelem datum, where we will cache the
* array element type data.
*/
nsubscripts = 0;
do
{
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 + 1, 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,
&parenttypoid, &parenttypmod,
&oldarraydatum, &oldarrayisnull);
/* Update cached type data if necessary */
if (arrayelem->parenttypoid != parenttypoid ||
arrayelem->parenttypmod != parenttypmod)
{
Oid arraytypoid;
int32 arraytypmod = parenttypmod;
int16 arraytyplen;
Oid elemtypoid;
int16 elemtyplen;
bool elemtypbyval;
char elemtypalign;
/* If target is domain over array, reduce to base type */
arraytypoid = getBaseTypeAndTypmod(parenttypoid,
&arraytypmod);
/* ... and identify the element type */
elemtypoid = get_element_type(arraytypoid);
if (!OidIsValid(elemtypoid))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("subscripted object is not an array")));
/* Collect needed data about the types */
arraytyplen = get_typlen(arraytypoid);
get_typlenbyvalalign(elemtypoid,
&elemtyplen,
&elemtypbyval,
&elemtypalign);
/* Now safe to update the cached data */
arrayelem->parenttypoid = parenttypoid;
arrayelem->parenttypmod = parenttypmod;
arrayelem->arraytypoid = arraytypoid;
arrayelem->arraytypmod = arraytypmod;
arrayelem->arraytyplen = arraytyplen;
arrayelem->elemtypoid = elemtypoid;
arrayelem->elemtyplen = elemtyplen;
arrayelem->elemtypbyval = elemtypbyval;
arrayelem->elemtypalign = elemtypalign;
}
/*
* 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")));
/*
* Clean up in case the subscript expression wasn't
* simple. We can't do exec_eval_cleanup, but we can do
* this much (which is safe because the integer subscript
* value is surely pass-by-value), and we must do it in
* case the next subscript expression isn't simple either.
*/
if (estate->eval_tuptable != NULL)
SPI_freetuptable(estate->eval_tuptable);
estate->eval_tuptable = NULL;
}
/* Now we can restore caller's SPI_execute result if any. */
Assert(estate->eval_tuptable == NULL);
estate->eval_tuptable = save_eval_tuptable;
/* Coerce source value to match array element type. */
coerced_value = exec_simple_cast_value(estate,
value,
valtype,
arrayelem->elemtypoid,
arrayelem->arraytypmod,
*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 (arrayelem->arraytyplen > 0 && /* fixed-length array? */
(oldarrayisnull || *isNull))
return;
/* empty array, if any, and newarraydatum are short-lived */
oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory);
if (oldarrayisnull)
oldarraydatum = PointerGetDatum(construct_empty_array(arrayelem->elemtypoid));
/*
* Build the modified array value.
*/
newarraydatum = array_set_element(oldarraydatum,
nsubscripts,
subscriptvals,
coerced_value,
*isNull,
arrayelem->arraytyplen,
arrayelem->elemtyplen,
arrayelem->elemtypbyval,
arrayelem->elemtypalign);
MemoryContextSwitchTo(oldcontext);
/*
* Assign the new array to the base variable. It's never NULL
* at this point. Note that if the target is a domain,
* coercing the base array type back up to the domain will
* happen within exec_assign_value.
*/
*isNull = false;
exec_assign_value(estate, target,
newarraydatum,
arrayelem->arraytypoid, isNull);
break;
}
default:
elog(ERROR, "unrecognized dtype: %d", target->dtype);
}
}
/*
* exec_eval_datum Get current value of a PLpgSQL_datum
*
* The type oid, typmod, 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,
int32 *typetypmod,
Datum *value,
bool *isnull)
{
MemoryContext oldcontext;
switch (datum->dtype)
{
case PLPGSQL_DTYPE_VAR:
{
PLpgSQL_var *var = (PLpgSQL_var *) datum;
*typeid = var->datatype->typoid;
*typetypmod = var->datatype->atttypmod;
*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");
*typeid = row->rowtupdesc->tdtypeid;
*typetypmod = row->rowtupdesc->tdtypmod;
*value = HeapTupleGetDatum(tup);
*isnull = false;
MemoryContextSwitchTo(oldcontext);
break;
}
case PLPGSQL_DTYPE_REC:
{
PLpgSQL_rec *rec = (PLpgSQL_rec *) datum;
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);
oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory);
*typeid = rec->tupdesc->tdtypeid;
*typetypmod = rec->tupdesc->tdtypmod;
*value = heap_copy_tuple_as_datum(rec->tup, rec->tupdesc);
*isnull = false;
MemoryContextSwitchTo(oldcontext);
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);
if (fno > 0)
*typetypmod = rec->tupdesc->attrs[fno - 1]->atttypmod;
else
*typetypmod = -1;
*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_datum_type_info Get datatype etc of a PLpgSQL_datum
*
* An extended version of exec_get_datum_type, which also retrieves the
* typmod and collation of the datum.
*/
void
exec_get_datum_type_info(PLpgSQL_execstate *estate,
PLpgSQL_datum *datum,
Oid *typeid, int32 *typmod, Oid *collation)
{
switch (datum->dtype)
{
case PLPGSQL_DTYPE_VAR:
{
PLpgSQL_var *var = (PLpgSQL_var *) datum;
*typeid = var->datatype->typoid;
*typmod = var->datatype->atttypmod;
*collation = var->datatype->collation;
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;
/* do NOT return the mutable typmod of a RECORD variable */
*typmod = -1;
/* composite types are never collatable */
*collation = InvalidOid;
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;
/* do NOT return the mutable typmod of a RECORD variable */
*typmod = -1;
/* composite types are never collatable */
*collation = InvalidOid;
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);
if (fno > 0)
*typmod = rec->tupdesc->attrs[fno - 1]->atttypmod;
else
*typmod = -1;
if (fno > 0)
*collation = rec->tupdesc->attrs[fno - 1]->attcollation;
else /* no system column types have collation */
*collation = InvalidOid;
break;
}
default:
elog(ERROR, "unrecognized dtype: %d", datum->dtype);
*typeid = InvalidOid; /* keep compiler quiet */
*typmod = -1;
*collation = InvalidOid;
break;
}
}
/* ----------
* 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(estate, 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(estate, 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)));
/*
* Check that the expression returns exactly one column...
*/
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)));
/*
* ... and get the column's datatype.
*/
*rettype = SPI_gettypeid(estate->eval_tuptable->tupdesc, 1);
/*
* If there are no rows selected, the result is a NULL of that type.
*/
if (estate->eval_processed == 0)
{
*isNull = true;
return (Datum) 0;
}
/*
* Check that the expression returned no more than one row.
*/
if (estate->eval_processed != 1)
ereport(ERROR,
(errcode(ERRCODE_CARDINALITY_VIOLATION),
errmsg("query \"%s\" returned more than one row",
expr->query)));
/*
* Return the single result Datum.
*/
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 (hook function and possibly data values)
*/
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");
/*
* Make sure the portal doesn't get closed by the user statements we
* execute.
*/
PinPortal(portal);
/*
* 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);
exec_eval_cleanup(estate);
}
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);
exec_eval_cleanup(estate);
/*
* 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);
UnpinPortal(portal);
/*
* 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 cannot be handled by simple evaluation,
* return FALSE.
*
* Because we only store one execution tree for a simple expression, we
* can't handle recursion cases. So, if we see the tree is already busy
* with an evaluation in the current xact, we just return FALSE and let the
* caller run the expression the hard way. (Other alternatives such as
* creating a new tree for a recursive call either introduce memory leaks,
* or add enough bookkeeping to be doubtful wins anyway.) Another case that
* is covered by the expr_simple_in_use test is where a previous execution
* of the tree was aborted by an error: the tree may contain bogus state
* so we dare not re-use it.
*
* 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 call
* SPI_plan_get_cached_plan for 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;
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;
/*
* If expression is in use in current xact, don't touch it.
*/
if (expr->expr_simple_in_use && expr->expr_simple_lxid == curlxid)
return false;
/*
* Revalidate cached plan, so that we will notice if it became stale. (We
* need to hold a refcount while using the plan, anyway.)
*/
cplan = SPI_plan_get_cached_plan(expr->plan);
/*
* We can't get a failure here, because the number of CachedPlanSources in
* the SPI plan can't change from what exec_simple_check_plan saw; it's a
* property of the raw parsetree generated from the query text.
*/
Assert(cplan != NULL);
if (cplan->generation != expr->expr_simple_generation)
{
/* It got replanned ... is it still simple? */
exec_simple_recheck_plan(expr, cplan);
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_recheck_plan above.)
*/
if (expr->expr_simple_lxid != curlxid)
{
oldcontext = MemoryContextSwitchTo(estate->simple_eval_estate->es_query_cxt);
expr->expr_simple_state = ExecInitExpr(expr->expr_simple_expr, NULL);
expr->expr_simple_in_use = false;
expr->expr_simple_lxid = curlxid;
MemoryContextSwitchTo(oldcontext);
}
/*
* 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.
*
* 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;
/*
* Mark expression as busy for the duration of the ExecEvalExpr call.
*/
expr->expr_simple_in_use = true;
/*
* Finally we can call the executor to evaluate the expression
*/
*result = ExecEvalExpr(expr->expr_simple_state,
econtext,
isNull,
NULL);
/* Assorted cleanup */
expr->expr_simple_in_use = false;
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
*
* We fill in the values for any expression parameters that are plain
* PLpgSQL_var datums; these are cheap and safe to evaluate, and by setting
* them with PARAM_FLAG_CONST flags, we allow the planner to use those values
* in custom plans. However, parameters that are not plain PLpgSQL_vars
* should not be evaluated here, because they could throw errors (for example
* "no such record field") and we do not want that to happen in a part of
* the expression that might never be evaluated at runtime. To handle those
* parameters, we set up a paramFetch hook for the executor to call when it
* wants a not-presupplied value.
*
* 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;
/*
* We must have created the SPIPlan already (hence, query text has been
* parsed/analyzed at least once); else we cannot rely on expr->paramnos.
*/
Assert(expr->plan != NULL);
/*
* Could we re-use these arrays instead of palloc'ing a new one each time?
* However, we'd have to re-fill the array each time anyway, since new
* values might have been assigned to the variables.
*/
if (!bms_is_empty(expr->paramnos))
{
int dno;
paramLI = (ParamListInfo)
palloc0(offsetof(ParamListInfoData, params) +
estate->ndatums * 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;
/* Instantiate values for "safe" parameters of the expression */
dno = -1;
while ((dno = bms_next_member(expr->paramnos, dno)) >= 0)
{
PLpgSQL_datum *datum = estate->datums[dno];
if (datum->dtype == PLPGSQL_DTYPE_VAR)
{
PLpgSQL_var *var = (PLpgSQL_var *) datum;
ParamExternData *prm = &paramLI->params[dno];
prm->value = var->value;
prm->isnull = var->isnull;
prm->pflags = PARAM_FLAG_CONST;
prm->ptype = var->datatype->typoid;
}
}
/*
* 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. (Should be set already, but let's be sure.)
*/
expr->func = estate->func;
}
else
{
/*
* Expression requires no parameters. Be sure we represent this case
* as a NULL ParamListInfo, so that plancache.c knows there is no
* point in a custom plan.
*/
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;
int32 prmtypmod;
/* 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 = &params->params[dno];
exec_eval_datum(estate, datum,
&prm->ptype, &prmtypmod,
&prm->value, &prm->isnull);
}
/* ----------
* exec_move_row Move one tuple's values into a record or row
*
* Since this uses exec_assign_value, caller should eventually call
* exec_eval_cleanup to prevent long-term memory leaks.
* ----------
*/
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;
/*
* InvalidOid is OK because exec_assign_value doesn't care
* about the type of a source NULL
*/
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;
int32 fieldtypmod;
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, &fieldtypmod,
&dvalues[i], &nulls[i]);
if (fieldtypeid != tupdesc->attrs[i]->atttypid)
return NULL;
/* XXX should we insist on typmod match, too? */
}
tuple = heap_form_tuple(tupdesc, dvalues, nulls);
pfree(dvalues);
pfree(nulls);
return tuple;
}
/* ----------
* get_tuple_from_datum extract a tuple from a composite Datum
*
* Returns a freshly palloc'd HeapTuple.
*
* Note: it's caller's responsibility to be sure value is of composite type.
* ----------
*/
static HeapTuple
get_tuple_from_datum(Datum value)
{
HeapTupleHeader td = DatumGetHeapTupleHeader(value);
HeapTupleData tmptup;
/* Build a temporary HeapTuple control structure */
tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
ItemPointerSetInvalid(&(tmptup.t_self));
tmptup.t_tableOid = InvalidOid;
tmptup.t_data = td;
/* Build a copy and return it */
return heap_copytuple(&tmptup);
}
/* ----------
* get_tupdesc_from_datum get a tuple descriptor for a composite Datum
*
* Returns a pointer to the TupleDesc of the tuple's rowtype.
* Caller is responsible for calling ReleaseTupleDesc when done with it.
*
* Note: it's caller's responsibility to be sure value is of composite type.
* ----------
*/
static TupleDesc
get_tupdesc_from_datum(Datum value)
{
HeapTupleHeader td = DatumGetHeapTupleHeader(value);
Oid tupType;
int32 tupTypmod;
/* Extract rowtype info and find a tupdesc */
tupType = HeapTupleHeaderGetTypeId(td);
tupTypmod = HeapTupleHeaderGetTypMod(td);
return lookup_rowtype_tupdesc(tupType, tupTypmod);
}
/* ----------
* exec_move_row_from_datum Move a composite Datum into a record or row
*
* This is equivalent to get_tuple_from_datum() followed by exec_move_row(),
* but we avoid constructing an intermediate physical copy of the tuple.
* ----------
*/
static void
exec_move_row_from_datum(PLpgSQL_execstate *estate,
PLpgSQL_rec *rec,
PLpgSQL_row *row,
Datum value)
{
HeapTupleHeader td = DatumGetHeapTupleHeader(value);
Oid tupType;
int32 tupTypmod;
TupleDesc tupdesc;
HeapTupleData tmptup;
/* 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;
/* Do the move */
exec_move_row(estate, rec, row, &tmptup, tupdesc);
/* Release tupdesc usage count */
ReleaseTupleDesc(tupdesc);
}
/* ----------
* convert_value_to_string Convert a non-null Datum to C string
*
* Note: the result is in the estate's eval_econtext, and will be cleared
* by the next exec_eval_cleanup() call. The invoked output function might
* leave additional cruft there as well, so just pfree'ing the result string
* would not be enough to avoid memory leaks if we did not do it like this.
* In most usages the Datum being passed in is also in that context (if
* pass-by-reference) and so an exec_eval_cleanup() call is needed anyway.
*
* Note: not caching the conversion function lookup is bad for performance.
* ----------
*/
static char *
convert_value_to_string(PLpgSQL_execstate *estate, Datum value, Oid valtype)
{
char *result;
MemoryContext oldcontext;
Oid typoutput;
bool typIsVarlena;
oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory);
getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
result = OidOutputFunctionCall(typoutput, value);
MemoryContextSwitchTo(oldcontext);
return result;
}
/* ----------
* exec_cast_value Cast a value if required
*
* Note: the estate's eval_econtext is used for temporary storage, and may
* also contain the result Datum if we have to do a conversion to a pass-
* by-reference data type. Be sure to do an exec_eval_cleanup() call when
* done with the result.
* ----------
*/
static Datum
exec_cast_value(PLpgSQL_execstate *estate,
Datum value, Oid valtype,
Oid reqtype,
FmgrInfo *reqinput,
Oid reqtypioparam,
int32 reqtypmod,
bool isnull)
{
/*
* If the type of the given value isn't what's requested, convert it.
*/
if (valtype != reqtype || reqtypmod != -1)
{
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory);
if (!isnull)
{
char *extval;
extval = convert_value_to_string(estate, value, valtype);
value = InputFunctionCall(reqinput, extval,
reqtypioparam, reqtypmod);
}
else
{
value = InputFunctionCall(reqinput, NULL,
reqtypioparam, reqtypmod);
}
MemoryContextSwitchTo(oldcontext);
}
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(PLpgSQL_execstate *estate,
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(estate,
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_NullIfExpr:
{
NullIfExpr *expr = (NullIfExpr *) 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_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)
{
List *plansources;
CachedPlanSource *plansource;
Query *query;
CachedPlan *cplan;
/*
* Initialize to "not simple", and remember the plan generation number we
* last checked. (If we don't get as far as obtaining a plan to check, we
* just leave expr_simple_generation set to 0.)
*/
expr->expr_simple_expr = NULL;
expr->expr_simple_generation = 0;
/*
* We can only test queries that resulted in exactly one CachedPlanSource
*/
plansources = SPI_plan_get_plan_sources(expr->plan);
if (list_length(plansources) != 1)
return;
plansource = (CachedPlanSource *) linitial(plansources);
/*
* Do some checking on the analyzed-and-rewritten form of the query. These
* checks are basically redundant with the tests in
* exec_simple_recheck_plan, but the point is to avoid building a plan if
* possible. Since this function is only called immediately after
* creating the CachedPlanSource, we need not worry about the query being
* stale.
*/
/*
* 1. There must be one single querytree.
*/
if (list_length(plansource->query_list) != 1)
return;
query = (Query *) linitial(plansource->query_list);
/*
* 2. It must be a plain SELECT query without any input tables
*/
if (!IsA(query, Query))
return;
if (query->commandType != CMD_SELECT)
return;
if (query->rtable != NIL)
return;
/*
* 3. Can't have any subplans, aggregates, qual clauses either
*/
if (query->hasAggs ||
query->hasWindowFuncs ||
query->hasSubLinks ||
query->hasForUpdate ||
query->cteList ||
query->jointree->quals ||
query->groupClause ||
query->havingQual ||
query->windowClause ||
query->distinctClause ||
query->sortClause ||
query->limitOffset ||
query->limitCount ||
query->setOperations)
return;
/*
* 4. The query must have a single attribute as result
*/
if (list_length(query->targetList) != 1)
return;
/*
* OK, it seems worth constructing a plan for more careful checking.
*/
/* Get the generic plan for the query */
cplan = SPI_plan_get_cached_plan(expr->plan);
/* Can't fail, because we checked for a single CachedPlanSource above */
Assert(cplan != NULL);
/* Share the remaining work with recheck code path */
exec_simple_recheck_plan(expr, cplan);
/* Release our plan refcount */
ReleaseCachedPlan(cplan, true);
}
/*
* exec_simple_recheck_plan --- check for simple plan once we have CachedPlan
*/
static void
exec_simple_recheck_plan(PLpgSQL_expr *expr, CachedPlan *cplan)
{
PlannedStmt *stmt;
Plan *plan;
TargetEntry *tle;
/*
* Initialize to "not simple", and remember the plan generation number we
* last checked.
*/
expr->expr_simple_expr = NULL;
expr->expr_simple_generation = cplan->generation;
/*
* 1. There must be one single plantree
*/
if (list_length(cplan->stmt_list) != 1)
return;
stmt = (PlannedStmt *) linitial(cplan->stmt_list);
/*
* 2. It must be a RESULT plan --> no scan's required
*/
if (!IsA(stmt, PlannedStmt))
return;
if (stmt->commandType != CMD_SELECT)
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_in_use = false;
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 = BoolGetDatum(state);
var->isnull = false;
}
/*
* plpgsql_create_econtext --- create an eval_econtext for the current function
*
* We may need to create a new shared_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.
*
* Note that this path is never taken when executing a DO block; the
* required EState was already made by plpgsql_inline_handler.
*/
if (estate->simple_eval_estate == NULL)
{
MemoryContext oldcontext;
Assert(shared_simple_eval_estate == NULL);
oldcontext = MemoryContextSwitchTo(TopTransactionContext);
shared_simple_eval_estate = CreateExecutorState();
estate->simple_eval_estate = shared_simple_eval_estate;
MemoryContextSwitchTo(oldcontext);
}
/*
* Create a child econtext for the current function.
*/
estate->eval_econtext = CreateExprContext(estate->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_COMMIT || event == XACT_EVENT_PREPARE)
{
/* Shouldn't be any econtext stack entries left at commit */
Assert(simple_econtext_stack == NULL);
if (shared_simple_eval_estate)
FreeExecutorState(shared_simple_eval_estate);
shared_simple_eval_estate = NULL;
}
else if (event == XACT_EVENT_ABORT)
{
simple_econtext_stack = NULL;
shared_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 econtexts belong to which level of subxact.
*/
void
plpgsql_subxact_cb(SubXactEvent event, SubTransactionId mySubid,
SubTransactionId parentSubid, void *arg)
{
if (event == SUBXACT_EVENT_COMMIT_SUB || event == SUBXACT_EVENT_ABORT_SUB)
{
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;
if (ppd->types[i] == UNKNOWNOID)
{
/*
* Treat 'unknown' parameters as text, since that's what most
* people would expect. SPI_execute_with_args can coerce unknown
* constants in a more intelligent way, but not unknown Params.
* This code also takes care of copying into the right context.
* Note we assume 'unknown' has the representation of C-string.
*/
ppd->types[i] = TEXTOID;
if (!isnull)
{
ppd->values[i] = CStringGetTextDatum(DatumGetCString(ppd->values[i]));
ppd->freevals[i] = true;
}
}
/* pass-by-ref non null values must be copied into plpgsql context */
else 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,
const char *portalname,
int cursorOptions)
{
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(estate, query, restype);
/* copy it out of the temporary context before we clean up */
querystr = pstrdup(querystr);
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(portalname,
querystr,
ppd->nargs, ppd->types,
ppd->values, ppd->nulls,
estate->readonly_func,
cursorOptions);
free_params_data(ppd);
}
else
{
portal = SPI_cursor_open_with_args(portalname,
querystr,
0, NULL,
NULL, NULL,
estate->readonly_func,
cursorOptions);
}
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;
}
/*
* Return a formatted string with information about an expression's parameters,
* or NULL if the expression does not take any parameters.
*/
static char *
format_expr_params(PLpgSQL_execstate *estate,
const PLpgSQL_expr *expr)
{
int paramno;
int dno;
StringInfoData paramstr;
if (!expr->paramnos)
return NULL;
initStringInfo(&paramstr);
paramno = 0;
dno = -1;
while ((dno = bms_next_member(expr->paramnos, dno)) >= 0)
{
Datum paramdatum;
Oid paramtypeid;
bool paramisnull;
int32 paramtypmod;
PLpgSQL_var *curvar;
curvar = (PLpgSQL_var *) estate->datums[dno];
exec_eval_datum(estate, (PLpgSQL_datum *) curvar, &paramtypeid,
&paramtypmod, &paramdatum, &paramisnull);
appendStringInfo(&paramstr, "%s%s = ",
paramno > 0 ? ", " : "",
curvar->refname);
if (paramisnull)
appendStringInfoString(&paramstr, "NULL");
else
{
char *value = convert_value_to_string(estate, paramdatum, paramtypeid);
char *p;
appendStringInfoCharMacro(&paramstr, '\'');
for (p = value; *p; p++)
{
if (*p == '\'') /* double single quotes */
appendStringInfoCharMacro(&paramstr, *p);
appendStringInfoCharMacro(&paramstr, *p);
}
appendStringInfoCharMacro(&paramstr, '\'');
}
paramno++;
}
return paramstr.data;
}
/*
* Return a formatted string with information about PreparedParamsData, or NULL
* if there are no parameters.
*/
static char *
format_preparedparamsdata(PLpgSQL_execstate *estate,
const PreparedParamsData *ppd)
{
int paramno;
StringInfoData paramstr;
if (!ppd)
return NULL;
initStringInfo(&paramstr);
for (paramno = 0; paramno < ppd->nargs; paramno++)
{
appendStringInfo(&paramstr, "%s$%d = ",
paramno > 0 ? ", " : "",
paramno + 1);
if (ppd->nulls[paramno] == 'n')
appendStringInfoString(&paramstr, "NULL");
else
{
char *value = convert_value_to_string(estate, ppd->values[paramno], ppd->types[paramno]);
char *p;
appendStringInfoCharMacro(&paramstr, '\'');
for (p = value; *p; p++)
{
if (*p == '\'') /* double single quotes */
appendStringInfoCharMacro(&paramstr, *p);
appendStringInfoCharMacro(&paramstr, *p);
}
appendStringInfoCharMacro(&paramstr, '\'');
}
}
return paramstr.data;
}