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pl_exec.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pl_exec.c - Executor for the PL/pgSQL
4  * procedural language
5  *
6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/pl/plpgsql/src/pl_exec.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 
16 #include "postgres.h"
17 
18 #include <ctype.h>
19 
20 #include "access/detoast.h"
21 #include "access/htup_details.h"
22 #include "access/transam.h"
23 #include "access/tupconvert.h"
24 #include "catalog/pg_proc.h"
25 #include "catalog/pg_type.h"
26 #include "commands/defrem.h"
27 #include "executor/execExpr.h"
28 #include "executor/spi.h"
29 #include "executor/tstoreReceiver.h"
30 #include "funcapi.h"
31 #include "mb/stringinfo_mb.h"
32 #include "miscadmin.h"
33 #include "nodes/nodeFuncs.h"
34 #include "optimizer/optimizer.h"
35 #include "parser/parse_coerce.h"
36 #include "parser/parse_type.h"
37 #include "parser/scansup.h"
38 #include "plpgsql.h"
39 #include "storage/proc.h"
40 #include "tcop/cmdtag.h"
41 #include "tcop/pquery.h"
42 #include "tcop/tcopprot.h"
43 #include "tcop/utility.h"
44 #include "utils/array.h"
45 #include "utils/builtins.h"
46 #include "utils/datum.h"
47 #include "utils/fmgroids.h"
48 #include "utils/lsyscache.h"
49 #include "utils/memutils.h"
50 #include "utils/rel.h"
51 #include "utils/snapmgr.h"
52 #include "utils/syscache.h"
53 #include "utils/typcache.h"
54 
55 /*
56  * All plpgsql function executions within a single transaction share the same
57  * executor EState for evaluating "simple" expressions. Each function call
58  * creates its own "eval_econtext" ExprContext within this estate for
59  * per-evaluation workspace. eval_econtext is freed at normal function exit,
60  * and the EState is freed at transaction end (in case of error, we assume
61  * that the abort mechanisms clean it all up). Furthermore, any exception
62  * block within a function has to have its own eval_econtext separate from
63  * the containing function's, so that we can clean up ExprContext callbacks
64  * properly at subtransaction exit. We maintain a stack that tracks the
65  * individual econtexts so that we can clean up correctly at subxact exit.
66  *
67  * This arrangement is a bit tedious to maintain, but it's worth the trouble
68  * so that we don't have to re-prepare simple expressions on each trip through
69  * a function. (We assume the case to optimize is many repetitions of a
70  * function within a transaction.)
71  *
72  * However, there's no value in trying to amortize simple expression setup
73  * across multiple executions of a DO block (inline code block), since there
74  * can never be any. If we use the shared EState for a DO block, the expr
75  * state trees are effectively leaked till end of transaction, and that can
76  * add up if the user keeps on submitting DO blocks. Therefore, each DO block
77  * has its own simple-expression EState, which is cleaned up at exit from
78  * plpgsql_inline_handler(). DO blocks still use the simple_econtext_stack,
79  * though, so that subxact abort cleanup does the right thing.
80  *
81  * (However, if a DO block executes COMMIT or ROLLBACK, then exec_stmt_commit
82  * or exec_stmt_rollback will unlink it from the DO's simple-expression EState
83  * and create a new shared EState that will be used thenceforth. The original
84  * EState will be cleaned up when we get back to plpgsql_inline_handler. This
85  * is a bit ugly, but it isn't worth doing better, since scenarios like this
86  * can't result in indefinite accumulation of state trees.)
87  */
88 typedef struct SimpleEcontextStackEntry
89 {
90  ExprContext *stack_econtext; /* a stacked econtext */
91  SubTransactionId xact_subxid; /* ID for current subxact */
92  struct SimpleEcontextStackEntry *next; /* next stack entry up */
93 } SimpleEcontextStackEntry;
94 
95 static EState *shared_simple_eval_estate = NULL;
96 static SimpleEcontextStackEntry *simple_econtext_stack = NULL;
97 
98 /*
99  * In addition to the shared simple-eval EState, we have a shared resource
100  * owner that holds refcounts on the CachedPlans for any "simple" expressions
101  * we have evaluated in the current transaction. This allows us to avoid
102  * continually grabbing and releasing a plan refcount when a simple expression
103  * is used over and over. (DO blocks use their own resowner, in exactly the
104  * same way described above for shared_simple_eval_estate.)
105  */
106 static ResourceOwner shared_simple_eval_resowner = NULL;
107 
108 /*
109  * Memory management within a plpgsql function generally works with three
110  * contexts:
111  *
112  * 1. Function-call-lifespan data, such as variable values, is kept in the
113  * "main" context, a/k/a the "SPI Proc" context established by SPI_connect().
114  * This is usually the CurrentMemoryContext while running code in this module
115  * (which is not good, because careless coding can easily cause
116  * function-lifespan memory leaks, but we live with it for now).
117  *
118  * 2. Some statement-execution routines need statement-lifespan workspace.
119  * A suitable context is created on-demand by get_stmt_mcontext(), and must
120  * be reset at the end of the requesting routine. Error recovery will clean
121  * it up automatically. Nested statements requiring statement-lifespan
122  * workspace will result in a stack of such contexts, see push_stmt_mcontext().
123  *
124  * 3. We use the eval_econtext's per-tuple memory context for expression
125  * evaluation, and as a general-purpose workspace for short-lived allocations.
126  * Such allocations usually aren't explicitly freed, but are left to be
127  * cleaned up by a context reset, typically done by exec_eval_cleanup().
128  *
129  * These macros are for use in making short-lived allocations:
130  */
131 #define get_eval_mcontext(estate) \
132  ((estate)->eval_econtext->ecxt_per_tuple_memory)
133 #define eval_mcontext_alloc(estate, sz) \
134  MemoryContextAlloc(get_eval_mcontext(estate), sz)
135 #define eval_mcontext_alloc0(estate, sz) \
136  MemoryContextAllocZero(get_eval_mcontext(estate), sz)
137 
138 /*
139  * We use a session-wide hash table for caching cast information.
140  *
141  * Once built, the compiled expression trees (cast_expr fields) survive for
142  * the life of the session. At some point it might be worth invalidating
143  * those after pg_cast changes, but for the moment we don't bother.
144  *
145  * The evaluation state trees (cast_exprstate) are managed in the same way as
146  * simple expressions (i.e., we assume cast expressions are always simple).
147  *
148  * As with simple expressions, DO blocks don't use the shared hash table but
149  * must have their own. This isn't ideal, but we don't want to deal with
150  * multiple simple_eval_estates within a DO block.
151  */
152 typedef struct /* lookup key for cast info */
153 {
154  /* NB: we assume this struct contains no padding bytes */
155  Oid srctype; /* source type for cast */
156  Oid dsttype; /* destination type for cast */
157  int32 srctypmod; /* source typmod for cast */
158  int32 dsttypmod; /* destination typmod for cast */
159 } plpgsql_CastHashKey;
160 
161 typedef struct /* cast_hash table entry */
162 {
163  plpgsql_CastHashKey key; /* hash key --- MUST BE FIRST */
164  Expr *cast_expr; /* cast expression, or NULL if no-op cast */
165  CachedExpression *cast_cexpr; /* cached expression backing the above */
166  /* ExprState is valid only when cast_lxid matches current LXID */
167  ExprState *cast_exprstate; /* expression's eval tree */
168  bool cast_in_use; /* true while we're executing eval tree */
169  LocalTransactionId cast_lxid;
170 } plpgsql_CastHashEntry;
171 
172 static MemoryContext shared_cast_context = NULL;
173 static HTAB *shared_cast_hash = NULL;
174 
175 /*
176  * LOOP_RC_PROCESSING encapsulates common logic for looping statements to
177  * handle return/exit/continue result codes from the loop body statement(s).
178  * It's meant to be used like this:
179  *
180  * int rc = PLPGSQL_RC_OK;
181  * for (...)
182  * {
183  * ...
184  * rc = exec_stmts(estate, stmt->body);
185  * LOOP_RC_PROCESSING(stmt->label, break);
186  * ...
187  * }
188  * return rc;
189  *
190  * If execution of the loop should terminate, LOOP_RC_PROCESSING will execute
191  * "exit_action" (typically a "break" or "goto"), after updating "rc" to the
192  * value the current statement should return. If execution should continue,
193  * LOOP_RC_PROCESSING will do nothing except reset "rc" to PLPGSQL_RC_OK.
194  *
195  * estate and rc are implicit arguments to the macro.
196  * estate->exitlabel is examined and possibly updated.
197  */
198 #define LOOP_RC_PROCESSING(looplabel, exit_action) \
199  if (rc == PLPGSQL_RC_RETURN) \
200  { \
201  /* RETURN, so propagate RC_RETURN out */ \
202  exit_action; \
203  } \
204  else if (rc == PLPGSQL_RC_EXIT) \
205  { \
206  if (estate->exitlabel == NULL) \
207  { \
208  /* unlabeled EXIT terminates this loop */ \
209  rc = PLPGSQL_RC_OK; \
210  exit_action; \
211  } \
212  else if ((looplabel) != NULL && \
213  strcmp(looplabel, estate->exitlabel) == 0) \
214  { \
215  /* labeled EXIT matching this loop, so terminate loop */ \
216  estate->exitlabel = NULL; \
217  rc = PLPGSQL_RC_OK; \
218  exit_action; \
219  } \
220  else \
221  { \
222  /* non-matching labeled EXIT, propagate RC_EXIT out */ \
223  exit_action; \
224  } \
225  } \
226  else if (rc == PLPGSQL_RC_CONTINUE) \
227  { \
228  if (estate->exitlabel == NULL) \
229  { \
230  /* unlabeled CONTINUE matches this loop, so continue in loop */ \
231  rc = PLPGSQL_RC_OK; \
232  } \
233  else if ((looplabel) != NULL && \
234  strcmp(looplabel, estate->exitlabel) == 0) \
235  { \
236  /* labeled CONTINUE matching this loop, so continue in loop */ \
237  estate->exitlabel = NULL; \
238  rc = PLPGSQL_RC_OK; \
239  } \
240  else \
241  { \
242  /* non-matching labeled CONTINUE, propagate RC_CONTINUE out */ \
243  exit_action; \
244  } \
245  } \
246  else \
247  Assert(rc == PLPGSQL_RC_OK)
248 
249 /************************************************************
250  * Local function forward declarations
251  ************************************************************/
252 static void coerce_function_result_tuple(PLpgSQL_execstate *estate,
253  TupleDesc tupdesc);
254 static void plpgsql_exec_error_callback(void *arg);
255 static void copy_plpgsql_datums(PLpgSQL_execstate *estate,
256  PLpgSQL_function *func);
257 static void plpgsql_fulfill_promise(PLpgSQL_execstate *estate,
258  PLpgSQL_var *var);
259 static MemoryContext get_stmt_mcontext(PLpgSQL_execstate *estate);
260 static void push_stmt_mcontext(PLpgSQL_execstate *estate);
261 static void pop_stmt_mcontext(PLpgSQL_execstate *estate);
262 
263 static int exec_toplevel_block(PLpgSQL_execstate *estate,
264  PLpgSQL_stmt_block *block);
265 static int exec_stmt_block(PLpgSQL_execstate *estate,
266  PLpgSQL_stmt_block *block);
267 static int exec_stmts(PLpgSQL_execstate *estate,
268  List *stmts);
269 static int exec_stmt_assign(PLpgSQL_execstate *estate,
270  PLpgSQL_stmt_assign *stmt);
271 static int exec_stmt_perform(PLpgSQL_execstate *estate,
272  PLpgSQL_stmt_perform *stmt);
273 static int exec_stmt_call(PLpgSQL_execstate *estate,
274  PLpgSQL_stmt_call *stmt);
275 static int exec_stmt_getdiag(PLpgSQL_execstate *estate,
276  PLpgSQL_stmt_getdiag *stmt);
277 static int exec_stmt_if(PLpgSQL_execstate *estate,
278  PLpgSQL_stmt_if *stmt);
279 static int exec_stmt_case(PLpgSQL_execstate *estate,
280  PLpgSQL_stmt_case *stmt);
281 static int exec_stmt_loop(PLpgSQL_execstate *estate,
282  PLpgSQL_stmt_loop *stmt);
283 static int exec_stmt_while(PLpgSQL_execstate *estate,
284  PLpgSQL_stmt_while *stmt);
285 static int exec_stmt_fori(PLpgSQL_execstate *estate,
286  PLpgSQL_stmt_fori *stmt);
287 static int exec_stmt_fors(PLpgSQL_execstate *estate,
288  PLpgSQL_stmt_fors *stmt);
289 static int exec_stmt_forc(PLpgSQL_execstate *estate,
290  PLpgSQL_stmt_forc *stmt);
291 static int exec_stmt_foreach_a(PLpgSQL_execstate *estate,
292  PLpgSQL_stmt_foreach_a *stmt);
293 static int exec_stmt_open(PLpgSQL_execstate *estate,
294  PLpgSQL_stmt_open *stmt);
295 static int exec_stmt_fetch(PLpgSQL_execstate *estate,
296  PLpgSQL_stmt_fetch *stmt);
297 static int exec_stmt_close(PLpgSQL_execstate *estate,
298  PLpgSQL_stmt_close *stmt);
299 static int exec_stmt_exit(PLpgSQL_execstate *estate,
300  PLpgSQL_stmt_exit *stmt);
301 static int exec_stmt_return(PLpgSQL_execstate *estate,
302  PLpgSQL_stmt_return *stmt);
303 static int exec_stmt_return_next(PLpgSQL_execstate *estate,
304  PLpgSQL_stmt_return_next *stmt);
305 static int exec_stmt_return_query(PLpgSQL_execstate *estate,
306  PLpgSQL_stmt_return_query *stmt);
307 static int exec_stmt_raise(PLpgSQL_execstate *estate,
308  PLpgSQL_stmt_raise *stmt);
309 static int exec_stmt_assert(PLpgSQL_execstate *estate,
310  PLpgSQL_stmt_assert *stmt);
311 static int exec_stmt_execsql(PLpgSQL_execstate *estate,
312  PLpgSQL_stmt_execsql *stmt);
313 static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
314  PLpgSQL_stmt_dynexecute *stmt);
315 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
316  PLpgSQL_stmt_dynfors *stmt);
317 static int exec_stmt_commit(PLpgSQL_execstate *estate,
318  PLpgSQL_stmt_commit *stmt);
319 static int exec_stmt_rollback(PLpgSQL_execstate *estate,
320  PLpgSQL_stmt_rollback *stmt);
321 
322 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
323  PLpgSQL_function *func,
324  ReturnSetInfo *rsi,
325  EState *simple_eval_estate,
326  ResourceOwner simple_eval_resowner);
327 static void exec_eval_cleanup(PLpgSQL_execstate *estate);
328 
329 static void exec_prepare_plan(PLpgSQL_execstate *estate,
330  PLpgSQL_expr *expr, int cursorOptions);
331 static void exec_simple_check_plan(PLpgSQL_execstate *estate, PLpgSQL_expr *expr);
332 static void exec_save_simple_expr(PLpgSQL_expr *expr, CachedPlan *cplan);
333 static void exec_check_rw_parameter(PLpgSQL_expr *expr);
334 static bool exec_eval_simple_expr(PLpgSQL_execstate *estate,
335  PLpgSQL_expr *expr,
336  Datum *result,
337  bool *isNull,
338  Oid *rettype,
339  int32 *rettypmod);
340 
341 static void exec_assign_expr(PLpgSQL_execstate *estate,
342  PLpgSQL_datum *target,
343  PLpgSQL_expr *expr);
344 static void exec_assign_c_string(PLpgSQL_execstate *estate,
345  PLpgSQL_datum *target,
346  const char *str);
347 static void exec_assign_value(PLpgSQL_execstate *estate,
348  PLpgSQL_datum *target,
349  Datum value, bool isNull,
350  Oid valtype, int32 valtypmod);
351 static void exec_eval_datum(PLpgSQL_execstate *estate,
352  PLpgSQL_datum *datum,
353  Oid *typeid,
354  int32 *typetypmod,
355  Datum *value,
356  bool *isnull);
357 static int exec_eval_integer(PLpgSQL_execstate *estate,
358  PLpgSQL_expr *expr,
359  bool *isNull);
360 static bool exec_eval_boolean(PLpgSQL_execstate *estate,
361  PLpgSQL_expr *expr,
362  bool *isNull);
363 static Datum exec_eval_expr(PLpgSQL_execstate *estate,
364  PLpgSQL_expr *expr,
365  bool *isNull,
366  Oid *rettype,
367  int32 *rettypmod);
368 static int exec_run_select(PLpgSQL_execstate *estate,
369  PLpgSQL_expr *expr, long maxtuples, Portal *portalP);
370 static int exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt,
371  Portal portal, bool prefetch_ok);
372 static ParamListInfo setup_param_list(PLpgSQL_execstate *estate,
373  PLpgSQL_expr *expr);
374 static ParamExternData *plpgsql_param_fetch(ParamListInfo params,
375  int paramid, bool speculative,
376  ParamExternData *workspace);
377 static void plpgsql_param_compile(ParamListInfo params, Param *param,
378  ExprState *state,
379  Datum *resv, bool *resnull);
380 static void plpgsql_param_eval_var(ExprState *state, ExprEvalStep *op,
381  ExprContext *econtext);
382 static void plpgsql_param_eval_var_ro(ExprState *state, ExprEvalStep *op,
383  ExprContext *econtext);
384 static void plpgsql_param_eval_recfield(ExprState *state, ExprEvalStep *op,
385  ExprContext *econtext);
386 static void plpgsql_param_eval_generic(ExprState *state, ExprEvalStep *op,
387  ExprContext *econtext);
388 static void plpgsql_param_eval_generic_ro(ExprState *state, ExprEvalStep *op,
389  ExprContext *econtext);
390 static void exec_move_row(PLpgSQL_execstate *estate,
391  PLpgSQL_variable *target,
392  HeapTuple tup, TupleDesc tupdesc);
393 static void revalidate_rectypeid(PLpgSQL_rec *rec);
394 static ExpandedRecordHeader *make_expanded_record_for_rec(PLpgSQL_execstate *estate,
395  PLpgSQL_rec *rec,
396  TupleDesc srctupdesc,
397  ExpandedRecordHeader *srcerh);
398 static void exec_move_row_from_fields(PLpgSQL_execstate *estate,
399  PLpgSQL_variable *target,
400  ExpandedRecordHeader *newerh,
401  Datum *values, bool *nulls,
402  TupleDesc tupdesc);
403 static bool compatible_tupdescs(TupleDesc src_tupdesc, TupleDesc dst_tupdesc);
404 static HeapTuple make_tuple_from_row(PLpgSQL_execstate *estate,
405  PLpgSQL_row *row,
406  TupleDesc tupdesc);
407 static TupleDesc deconstruct_composite_datum(Datum value,
408  HeapTupleData *tmptup);
409 static void exec_move_row_from_datum(PLpgSQL_execstate *estate,
410  PLpgSQL_variable *target,
411  Datum value);
412 static void instantiate_empty_record_variable(PLpgSQL_execstate *estate,
413  PLpgSQL_rec *rec);
414 static char *convert_value_to_string(PLpgSQL_execstate *estate,
415  Datum value, Oid valtype);
416 static inline Datum exec_cast_value(PLpgSQL_execstate *estate,
417  Datum value, bool *isnull,
418  Oid valtype, int32 valtypmod,
419  Oid reqtype, int32 reqtypmod);
420 static Datum do_cast_value(PLpgSQL_execstate *estate,
421  Datum value, bool *isnull,
422  Oid valtype, int32 valtypmod,
423  Oid reqtype, int32 reqtypmod);
424 static plpgsql_CastHashEntry *get_cast_hashentry(PLpgSQL_execstate *estate,
425  Oid srctype, int32 srctypmod,
426  Oid dsttype, int32 dsttypmod);
427 static void exec_init_tuple_store(PLpgSQL_execstate *estate);
428 static void exec_set_found(PLpgSQL_execstate *estate, bool state);
429 static void plpgsql_create_econtext(PLpgSQL_execstate *estate);
430 static void plpgsql_destroy_econtext(PLpgSQL_execstate *estate);
431 static void assign_simple_var(PLpgSQL_execstate *estate, PLpgSQL_var *var,
432  Datum newvalue, bool isnull, bool freeable);
433 static void assign_text_var(PLpgSQL_execstate *estate, PLpgSQL_var *var,
434  const char *str);
435 static void assign_record_var(PLpgSQL_execstate *estate, PLpgSQL_rec *rec,
436  ExpandedRecordHeader *erh);
437 static ParamListInfo exec_eval_using_params(PLpgSQL_execstate *estate,
438  List *params);
439 static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate,
440  PLpgSQL_expr *dynquery, List *params,
441  const char *portalname, int cursorOptions);
442 static char *format_expr_params(PLpgSQL_execstate *estate,
443  const PLpgSQL_expr *expr);
444 static char *format_preparedparamsdata(PLpgSQL_execstate *estate,
445  ParamListInfo paramLI);
446 static PLpgSQL_variable *make_callstmt_target(PLpgSQL_execstate *estate,
447  PLpgSQL_expr *expr);
448 
449 
450 /* ----------
451  * plpgsql_exec_function Called by the call handler for
452  * function execution.
453  *
454  * This is also used to execute inline code blocks (DO blocks). The only
455  * difference that this code is aware of is that for a DO block, we want
456  * to use a private simple_eval_estate and a private simple_eval_resowner,
457  * which are created and passed in by the caller. For regular functions,
458  * pass NULL, which implies using shared_simple_eval_estate and
459  * shared_simple_eval_resowner. (When using a private simple_eval_estate,
460  * we must also use a private cast hashtable, but that's taken care of
461  * within plpgsql_estate_setup.)
462  * procedure_resowner is a resowner that will survive for the duration
463  * of execution of this function/procedure. It is needed only if we
464  * are doing non-atomic execution and there are CALL or DO statements
465  * in the function; otherwise it can be NULL. We use it to hold refcounts
466  * on the CALL/DO statements' plans.
467  * ----------
468  */
469 Datum
470 plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo,
471  EState *simple_eval_estate,
472  ResourceOwner simple_eval_resowner,
473  ResourceOwner procedure_resowner,
474  bool atomic)
475 {
476  PLpgSQL_execstate estate;
477  ErrorContextCallback plerrcontext;
478  int i;
479  int rc;
480 
481  /*
482  * Setup the execution state
483  */
484  plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo,
485  simple_eval_estate, simple_eval_resowner);
486  estate.procedure_resowner = procedure_resowner;
487  estate.atomic = atomic;
488 
489  /*
490  * Setup error traceback support for ereport()
491  */
492  plerrcontext.callback = plpgsql_exec_error_callback;
493  plerrcontext.arg = &estate;
494  plerrcontext.previous = error_context_stack;
495  error_context_stack = &plerrcontext;
496 
497  /*
498  * Make local execution copies of all the datums
499  */
500  estate.err_text = gettext_noop("during initialization of execution state");
501  copy_plpgsql_datums(&estate, func);
502 
503  /*
504  * Store the actual call argument values into the appropriate variables
505  */
506  estate.err_text = gettext_noop("while storing call arguments into local variables");
507  for (i = 0; i < func->fn_nargs; i++)
508  {
509  int n = func->fn_argvarnos[i];
510 
511  switch (estate.datums[n]->dtype)
512  {
513  case PLPGSQL_DTYPE_VAR:
514  {
515  PLpgSQL_var *var = (PLpgSQL_var *) estate.datums[n];
516 
517  assign_simple_var(&estate, var,
518  fcinfo->args[i].value,
519  fcinfo->args[i].isnull,
520  false);
521 
522  /*
523  * Force any array-valued parameter to be stored in
524  * expanded form in our local variable, in hopes of
525  * improving efficiency of uses of the variable. (This is
526  * a hack, really: why only arrays? Need more thought
527  * about which cases are likely to win. See also
528  * typisarray-specific heuristic in exec_assign_value.)
529  *
530  * Special cases: If passed a R/W expanded pointer, assume
531  * we can commandeer the object rather than having to copy
532  * it. If passed a R/O expanded pointer, just keep it as
533  * the value of the variable for the moment. (We'll force
534  * it to R/W if the variable gets modified, but that may
535  * very well never happen.)
536  */
537  if (!var->isnull && var->datatype->typisarray)
538  {
539  if (VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(var->value)))
540  {
541  /* take ownership of R/W object */
542  assign_simple_var(&estate, var,
543  TransferExpandedObject(var->value,
544  estate.datum_context),
545  false,
546  true);
547  }
548  else if (VARATT_IS_EXTERNAL_EXPANDED_RO(DatumGetPointer(var->value)))
549  {
550  /* R/O pointer, keep it as-is until assigned to */
551  }
552  else
553  {
554  /* flat array, so force to expanded form */
555  assign_simple_var(&estate, var,
556  expand_array(var->value,
557  estate.datum_context,
558  NULL),
559  false,
560  true);
561  }
562  }
563  }
564  break;
565 
566  case PLPGSQL_DTYPE_REC:
567  {
568  PLpgSQL_rec *rec = (PLpgSQL_rec *) estate.datums[n];
569 
570  if (!fcinfo->args[i].isnull)
571  {
572  /* Assign row value from composite datum */
573  exec_move_row_from_datum(&estate,
574  (PLpgSQL_variable *) rec,
575  fcinfo->args[i].value);
576  }
577  else
578  {
579  /* If arg is null, set variable to null */
580  exec_move_row(&estate, (PLpgSQL_variable *) rec,
581  NULL, NULL);
582  }
583  /* clean up after exec_move_row() */
584  exec_eval_cleanup(&estate);
585  }
586  break;
587 
588  default:
589  /* Anything else should not be an argument variable */
590  elog(ERROR, "unrecognized dtype: %d", func->datums[i]->dtype);
591  }
592  }
593 
594  estate.err_text = gettext_noop("during function entry");
595 
596  /*
597  * Set the magic variable FOUND to false
598  */
599  exec_set_found(&estate, false);
600 
601  /*
602  * Let the instrumentation plugin peek at this function
603  */
604  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_beg)
605  ((*plpgsql_plugin_ptr)->func_beg) (&estate, func);
606 
607  /*
608  * Now call the toplevel block of statements
609  */
610  estate.err_text = NULL;
611  rc = exec_toplevel_block(&estate, func->action);
612  if (rc != PLPGSQL_RC_RETURN)
613  {
614  estate.err_text = NULL;
615  ereport(ERROR,
616  (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
617  errmsg("control reached end of function without RETURN")));
618  }
619 
620  /*
621  * We got a return value - process it
622  */
623  estate.err_text = gettext_noop("while casting return value to function's return type");
624 
625  fcinfo->isnull = estate.retisnull;
626 
627  if (estate.retisset)
628  {
629  ReturnSetInfo *rsi = estate.rsi;
630 
631  /* Check caller can handle a set result */
632  if (!rsi || !IsA(rsi, ReturnSetInfo) ||
633  (rsi->allowedModes & SFRM_Materialize) == 0)
634  ereport(ERROR,
635  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
636  errmsg("set-valued function called in context that cannot accept a set")));
637  rsi->returnMode = SFRM_Materialize;
638 
639  /* If we produced any tuples, send back the result */
640  if (estate.tuple_store)
641  {
642  MemoryContext oldcxt;
643 
644  rsi->setResult = estate.tuple_store;
645  oldcxt = MemoryContextSwitchTo(estate.tuple_store_cxt);
646  rsi->setDesc = CreateTupleDescCopy(estate.tuple_store_desc);
647  MemoryContextSwitchTo(oldcxt);
648  }
649  estate.retval = (Datum) 0;
650  fcinfo->isnull = true;
651  }
652  else if (!estate.retisnull)
653  {
654  /*
655  * Cast result value to function's declared result type, and copy it
656  * out to the upper executor memory context. We must treat tuple
657  * results specially in order to deal with cases like rowtypes
658  * involving dropped columns.
659  */
660  if (estate.retistuple)
661  {
662  /* Don't need coercion if rowtype is known to match */
663  if (func->fn_rettype == estate.rettype &&
664  func->fn_rettype != RECORDOID)
665  {
666  /*
667  * Copy the tuple result into upper executor memory context.
668  * However, if we have a R/W expanded datum, we can just
669  * transfer its ownership out to the upper context.
670  */
671  estate.retval = SPI_datumTransfer(estate.retval,
672  false,
673  -1);
674  }
675  else
676  {
677  /*
678  * Need to look up the expected result type. XXX would be
679  * better to cache the tupdesc instead of repeating
680  * get_call_result_type(), but the only easy place to save it
681  * is in the PLpgSQL_function struct, and that's too
682  * long-lived: composite types could change during the
683  * existence of a PLpgSQL_function.
684  */
685  Oid resultTypeId;
686  TupleDesc tupdesc;
687 
688  switch (get_call_result_type(fcinfo, &resultTypeId, &tupdesc))
689  {
690  case TYPEFUNC_COMPOSITE:
691  /* got the expected result rowtype, now coerce it */
692  coerce_function_result_tuple(&estate, tupdesc);
693  break;
694  case TYPEFUNC_COMPOSITE_DOMAIN:
695  /* got the expected result rowtype, now coerce it */
696  coerce_function_result_tuple(&estate, tupdesc);
697  /* and check domain constraints */
698  /* XXX allowing caching here would be good, too */
699  domain_check(estate.retval, false, resultTypeId,
700  NULL, NULL);
701  break;
702  case TYPEFUNC_RECORD:
703 
704  /*
705  * Failed to determine actual type of RECORD. We
706  * could raise an error here, but what this means in
707  * practice is that the caller is expecting any old
708  * generic rowtype, so we don't really need to be
709  * restrictive. Pass back the generated result as-is.
710  */
711  estate.retval = SPI_datumTransfer(estate.retval,
712  false,
713  -1);
714  break;
715  default:
716  /* shouldn't get here if retistuple is true ... */
717  elog(ERROR, "return type must be a row type");
718  break;
719  }
720  }
721  }
722  else
723  {
724  /* Scalar case: use exec_cast_value */
725  estate.retval = exec_cast_value(&estate,
726  estate.retval,
727  &fcinfo->isnull,
728  estate.rettype,
729  -1,
730  func->fn_rettype,
731  -1);
732 
733  /*
734  * If the function's return type isn't by value, copy the value
735  * into upper executor memory context. However, if we have a R/W
736  * expanded datum, we can just transfer its ownership out to the
737  * upper executor context.
738  */
739  if (!fcinfo->isnull && !func->fn_retbyval)
740  estate.retval = SPI_datumTransfer(estate.retval,
741  false,
742  func->fn_rettyplen);
743  }
744  }
745  else
746  {
747  /*
748  * We're returning a NULL, which normally requires no conversion work
749  * regardless of datatypes. But, if we are casting it to a domain
750  * return type, we'd better check that the domain's constraints pass.
751  */
752  if (func->fn_retisdomain)
753  estate.retval = exec_cast_value(&estate,
754  estate.retval,
755  &fcinfo->isnull,
756  estate.rettype,
757  -1,
758  func->fn_rettype,
759  -1);
760  }
761 
762  estate.err_text = gettext_noop("during function exit");
763 
764  /*
765  * Let the instrumentation plugin peek at this function
766  */
767  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_end)
768  ((*plpgsql_plugin_ptr)->func_end) (&estate, func);
769 
770  /* Clean up any leftover temporary memory */
771  plpgsql_destroy_econtext(&estate);
772  exec_eval_cleanup(&estate);
773  /* stmt_mcontext will be destroyed when function's main context is */
774 
775  /*
776  * Pop the error context stack
777  */
778  error_context_stack = plerrcontext.previous;
779 
780  /*
781  * Return the function's result
782  */
783  return estate.retval;
784 }
785 
786 /*
787  * Helper for plpgsql_exec_function: coerce composite result to the specified
788  * tuple descriptor, and copy it out to upper executor memory. This is split
789  * out mostly for cosmetic reasons --- the logic would be very deeply nested
790  * otherwise.
791  *
792  * estate->retval is updated in-place.
793  */
794 static void
795 coerce_function_result_tuple(PLpgSQL_execstate *estate, TupleDesc tupdesc)
796 {
797  HeapTuple rettup;
798  TupleDesc retdesc;
799  TupleConversionMap *tupmap;
800 
801  /* We assume exec_stmt_return verified that result is composite */
802  Assert(type_is_rowtype(estate->rettype));
803 
804  /* We can special-case expanded records for speed */
805  if (VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(estate->retval)))
806  {
807  ExpandedRecordHeader *erh = (ExpandedRecordHeader *) DatumGetEOHP(estate->retval);
808 
809  Assert(erh->er_magic == ER_MAGIC);
810 
811  /* Extract record's TupleDesc */
812  retdesc = expanded_record_get_tupdesc(erh);
813 
814  /* check rowtype compatibility */
815  tupmap = convert_tuples_by_position(retdesc,
816  tupdesc,
817  gettext_noop("returned record type does not match expected record type"));
818 
819  /* it might need conversion */
820  if (tupmap)
821  {
822  rettup = expanded_record_get_tuple(erh);
823  Assert(rettup);
824  rettup = execute_attr_map_tuple(rettup, tupmap);
825 
826  /*
827  * Copy tuple to upper executor memory, as a tuple Datum. Make
828  * sure it is labeled with the caller-supplied tuple type.
829  */
830  estate->retval = PointerGetDatum(SPI_returntuple(rettup, tupdesc));
831  /* no need to free map, we're about to return anyway */
832  }
833  else if (!(tupdesc->tdtypeid == erh->er_decltypeid ||
834  (tupdesc->tdtypeid == RECORDOID &&
835  !ExpandedRecordIsDomain(erh))))
836  {
837  /*
838  * The expanded record has the right physical tupdesc, but the
839  * wrong type ID. (Typically, the expanded record is RECORDOID
840  * but the function is declared to return a named composite type.
841  * As in exec_move_row_from_datum, we don't allow returning a
842  * composite-domain record from a function declared to return
843  * RECORD.) So we must flatten the record to a tuple datum and
844  * overwrite its type fields with the right thing. spi.c doesn't
845  * provide any easy way to deal with this case, so we end up
846  * duplicating the guts of datumCopy() :-(
847  */
848  Size resultsize;
849  HeapTupleHeader tuphdr;
850 
851  resultsize = EOH_get_flat_size(&erh->hdr);
852  tuphdr = (HeapTupleHeader) SPI_palloc(resultsize);
853  EOH_flatten_into(&erh->hdr, (void *) tuphdr, resultsize);
854  HeapTupleHeaderSetTypeId(tuphdr, tupdesc->tdtypeid);
855  HeapTupleHeaderSetTypMod(tuphdr, tupdesc->tdtypmod);
856  estate->retval = PointerGetDatum(tuphdr);
857  }
858  else
859  {
860  /*
861  * We need only copy result into upper executor memory context.
862  * However, if we have a R/W expanded datum, we can just transfer
863  * its ownership out to the upper executor context.
864  */
865  estate->retval = SPI_datumTransfer(estate->retval,
866  false,
867  -1);
868  }
869  }
870  else
871  {
872  /* Convert composite datum to a HeapTuple and TupleDesc */
873  HeapTupleData tmptup;
874 
875  retdesc = deconstruct_composite_datum(estate->retval, &tmptup);
876  rettup = &tmptup;
877 
878  /* check rowtype compatibility */
879  tupmap = convert_tuples_by_position(retdesc,
880  tupdesc,
881  gettext_noop("returned record type does not match expected record type"));
882 
883  /* it might need conversion */
884  if (tupmap)
885  rettup = execute_attr_map_tuple(rettup, tupmap);
886 
887  /*
888  * Copy tuple to upper executor memory, as a tuple Datum. Make sure
889  * it is labeled with the caller-supplied tuple type.
890  */
891  estate->retval = PointerGetDatum(SPI_returntuple(rettup, tupdesc));
892 
893  /* no need to free map, we're about to return anyway */
894 
895  ReleaseTupleDesc(retdesc);
896  }
897 }
898 
899 
900 /* ----------
901  * plpgsql_exec_trigger Called by the call handler for
902  * trigger execution.
903  * ----------
904  */
905 HeapTuple
906 plpgsql_exec_trigger(PLpgSQL_function *func,
907  TriggerData *trigdata)
908 {
909  PLpgSQL_execstate estate;
910  ErrorContextCallback plerrcontext;
911  int rc;
912  TupleDesc tupdesc;
913  PLpgSQL_rec *rec_new,
914  *rec_old;
915  HeapTuple rettup;
916 
917  /*
918  * Setup the execution state
919  */
920  plpgsql_estate_setup(&estate, func, NULL, NULL, NULL);
921  estate.trigdata = trigdata;
922 
923  /*
924  * Setup error traceback support for ereport()
925  */
926  plerrcontext.callback = plpgsql_exec_error_callback;
927  plerrcontext.arg = &estate;
928  plerrcontext.previous = error_context_stack;
929  error_context_stack = &plerrcontext;
930 
931  /*
932  * Make local execution copies of all the datums
933  */
934  estate.err_text = gettext_noop("during initialization of execution state");
935  copy_plpgsql_datums(&estate, func);
936 
937  /*
938  * Put the OLD and NEW tuples into record variables
939  *
940  * We set up expanded records for both variables even though only one may
941  * have a value. This allows record references to succeed in functions
942  * that are used for multiple trigger types. For example, we might have a
943  * test like "if (TG_OP = 'INSERT' and NEW.foo = 'xyz')", which should
944  * work regardless of the current trigger type. If a value is actually
945  * fetched from an unsupplied tuple, it will read as NULL.
946  */
947  tupdesc = RelationGetDescr(trigdata->tg_relation);
948 
949  rec_new = (PLpgSQL_rec *) (estate.datums[func->new_varno]);
950  rec_old = (PLpgSQL_rec *) (estate.datums[func->old_varno]);
951 
952  rec_new->erh = make_expanded_record_from_tupdesc(tupdesc,
953  estate.datum_context);
954  rec_old->erh = make_expanded_record_from_exprecord(rec_new->erh,
955  estate.datum_context);
956 
957  if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
958  {
959  /*
960  * Per-statement triggers don't use OLD/NEW variables
961  */
962  }
963  else if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
964  {
965  expanded_record_set_tuple(rec_new->erh, trigdata->tg_trigtuple,
966  false, false);
967  }
968  else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
969  {
970  expanded_record_set_tuple(rec_new->erh, trigdata->tg_newtuple,
971  false, false);
972  expanded_record_set_tuple(rec_old->erh, trigdata->tg_trigtuple,
973  false, false);
974 
975  /*
976  * In BEFORE trigger, stored generated columns are not computed yet,
977  * so make them null in the NEW row. (Only needed in UPDATE branch;
978  * in the INSERT case, they are already null, but in UPDATE, the field
979  * still contains the old value.) Alternatively, we could construct a
980  * whole new row structure without the generated columns, but this way
981  * seems more efficient and potentially less confusing.
982  */
983  if (tupdesc->constr && tupdesc->constr->has_generated_stored &&
984  TRIGGER_FIRED_BEFORE(trigdata->tg_event))
985  {
986  for (int i = 0; i < tupdesc->natts; i++)
987  if (TupleDescAttr(tupdesc, i)->attgenerated == ATTRIBUTE_GENERATED_STORED)
988  expanded_record_set_field_internal(rec_new->erh,
989  i + 1,
990  (Datum) 0,
991  true, /* isnull */
992  false, false);
993  }
994  }
995  else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
996  {
997  expanded_record_set_tuple(rec_old->erh, trigdata->tg_trigtuple,
998  false, false);
999  }
1000  else
1001  elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, or UPDATE");
1002 
1003  /* Make transition tables visible to this SPI connection */
1004  rc = SPI_register_trigger_data(trigdata);
1005  Assert(rc >= 0);
1006 
1007  estate.err_text = gettext_noop("during function entry");
1008 
1009  /*
1010  * Set the magic variable FOUND to false
1011  */
1012  exec_set_found(&estate, false);
1013 
1014  /*
1015  * Let the instrumentation plugin peek at this function
1016  */
1017  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_beg)
1018  ((*plpgsql_plugin_ptr)->func_beg) (&estate, func);
1019 
1020  /*
1021  * Now call the toplevel block of statements
1022  */
1023  estate.err_text = NULL;
1024  rc = exec_toplevel_block(&estate, func->action);
1025  if (rc != PLPGSQL_RC_RETURN)
1026  {
1027  estate.err_text = NULL;
1028  ereport(ERROR,
1029  (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
1030  errmsg("control reached end of trigger procedure without RETURN")));
1031  }
1032 
1033  estate.err_text = gettext_noop("during function exit");
1034 
1035  if (estate.retisset)
1036  ereport(ERROR,
1037  (errcode(ERRCODE_DATATYPE_MISMATCH),
1038  errmsg("trigger procedure cannot return a set")));
1039 
1040  /*
1041  * Check that the returned tuple structure has the same attributes, the
1042  * relation that fired the trigger has. A per-statement trigger always
1043  * needs to return NULL, so we ignore any return value the function itself
1044  * produces (XXX: is this a good idea?)
1045  *
1046  * XXX This way it is possible, that the trigger returns a tuple where
1047  * attributes don't have the correct atttypmod's length. It's up to the
1048  * trigger's programmer to ensure that this doesn't happen. Jan
1049  */
1050  if (estate.retisnull || !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
1051  rettup = NULL;
1052  else
1053  {
1054  TupleDesc retdesc;
1055  TupleConversionMap *tupmap;
1056 
1057  /* We assume exec_stmt_return verified that result is composite */
1058  Assert(type_is_rowtype(estate.rettype));
1059 
1060  /* We can special-case expanded records for speed */
1061  if (VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(estate.retval)))
1062  {
1063  ExpandedRecordHeader *erh = (ExpandedRecordHeader *) DatumGetEOHP(estate.retval);
1064 
1065  Assert(erh->er_magic == ER_MAGIC);
1066 
1067  /* Extract HeapTuple and TupleDesc */
1068  rettup = expanded_record_get_tuple(erh);
1069  Assert(rettup);
1070  retdesc = expanded_record_get_tupdesc(erh);
1071 
1072  if (retdesc != RelationGetDescr(trigdata->tg_relation))
1073  {
1074  /* check rowtype compatibility */
1075  tupmap = convert_tuples_by_position(retdesc,
1076  RelationGetDescr(trigdata->tg_relation),
1077  gettext_noop("returned row structure does not match the structure of the triggering table"));
1078  /* it might need conversion */
1079  if (tupmap)
1080  rettup = execute_attr_map_tuple(rettup, tupmap);
1081  /* no need to free map, we're about to return anyway */
1082  }
1083 
1084  /*
1085  * Copy tuple to upper executor memory. But if user just did
1086  * "return new" or "return old" without changing anything, there's
1087  * no need to copy; we can return the original tuple (which will
1088  * save a few cycles in trigger.c as well as here).
1089  */
1090  if (rettup != trigdata->tg_newtuple &&
1091  rettup != trigdata->tg_trigtuple)
1092  rettup = SPI_copytuple(rettup);
1093  }
1094  else
1095  {
1096  /* Convert composite datum to a HeapTuple and TupleDesc */
1097  HeapTupleData tmptup;
1098 
1099  retdesc = deconstruct_composite_datum(estate.retval, &tmptup);
1100  rettup = &tmptup;
1101 
1102  /* check rowtype compatibility */
1103  tupmap = convert_tuples_by_position(retdesc,
1104  RelationGetDescr(trigdata->tg_relation),
1105  gettext_noop("returned row structure does not match the structure of the triggering table"));
1106  /* it might need conversion */
1107  if (tupmap)
1108  rettup = execute_attr_map_tuple(rettup, tupmap);
1109 
1110  ReleaseTupleDesc(retdesc);
1111  /* no need to free map, we're about to return anyway */
1112 
1113  /* Copy tuple to upper executor memory */
1114  rettup = SPI_copytuple(rettup);
1115  }
1116  }
1117 
1118  /*
1119  * Let the instrumentation plugin peek at this function
1120  */
1121  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_end)
1122  ((*plpgsql_plugin_ptr)->func_end) (&estate, func);
1123 
1124  /* Clean up any leftover temporary memory */
1125  plpgsql_destroy_econtext(&estate);
1126  exec_eval_cleanup(&estate);
1127  /* stmt_mcontext will be destroyed when function's main context is */
1128 
1129  /*
1130  * Pop the error context stack
1131  */
1132  error_context_stack = plerrcontext.previous;
1133 
1134  /*
1135  * Return the trigger's result
1136  */
1137  return rettup;
1138 }
1139 
1140 /* ----------
1141  * plpgsql_exec_event_trigger Called by the call handler for
1142  * event trigger execution.
1143  * ----------
1144  */
1145 void
1146 plpgsql_exec_event_trigger(PLpgSQL_function *func, EventTriggerData *trigdata)
1147 {
1148  PLpgSQL_execstate estate;
1149  ErrorContextCallback plerrcontext;
1150  int rc;
1151 
1152  /*
1153  * Setup the execution state
1154  */
1155  plpgsql_estate_setup(&estate, func, NULL, NULL, NULL);
1156  estate.evtrigdata = trigdata;
1157 
1158  /*
1159  * Setup error traceback support for ereport()
1160  */
1161  plerrcontext.callback = plpgsql_exec_error_callback;
1162  plerrcontext.arg = &estate;
1163  plerrcontext.previous = error_context_stack;
1164  error_context_stack = &plerrcontext;
1165 
1166  /*
1167  * Make local execution copies of all the datums
1168  */
1169  estate.err_text = gettext_noop("during initialization of execution state");
1170  copy_plpgsql_datums(&estate, func);
1171 
1172  /*
1173  * Let the instrumentation plugin peek at this function
1174  */
1175  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_beg)
1176  ((*plpgsql_plugin_ptr)->func_beg) (&estate, func);
1177 
1178  /*
1179  * Now call the toplevel block of statements
1180  */
1181  estate.err_text = NULL;
1182  rc = exec_toplevel_block(&estate, func->action);
1183  if (rc != PLPGSQL_RC_RETURN)
1184  {
1185  estate.err_text = NULL;
1186  ereport(ERROR,
1187  (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
1188  errmsg("control reached end of trigger procedure without RETURN")));
1189  }
1190 
1191  estate.err_text = gettext_noop("during function exit");
1192 
1193  /*
1194  * Let the instrumentation plugin peek at this function
1195  */
1196  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->func_end)
1197  ((*plpgsql_plugin_ptr)->func_end) (&estate, func);
1198 
1199  /* Clean up any leftover temporary memory */
1200  plpgsql_destroy_econtext(&estate);
1201  exec_eval_cleanup(&estate);
1202  /* stmt_mcontext will be destroyed when function's main context is */
1203 
1204  /*
1205  * Pop the error context stack
1206  */
1207  error_context_stack = plerrcontext.previous;
1208 }
1209 
1210 /*
1211  * error context callback to let us supply a call-stack traceback
1212  */
1213 static void
1214 plpgsql_exec_error_callback(void *arg)
1215 {
1216  PLpgSQL_execstate *estate = (PLpgSQL_execstate *) arg;
1217 
1218  if (estate->err_text != NULL)
1219  {
1220  /*
1221  * We don't expend the cycles to run gettext() on err_text unless we
1222  * actually need it. Therefore, places that set up err_text should
1223  * use gettext_noop() to ensure the strings get recorded in the
1224  * message dictionary.
1225  *
1226  * If both err_text and err_stmt are set, use the err_text as
1227  * description, but report the err_stmt's line number. When err_stmt
1228  * is not set, we're in function entry/exit, or some such place not
1229  * attached to a specific line number.
1230  */
1231  if (estate->err_stmt != NULL)
1232  {
1233  /*
1234  * translator: last %s is a phrase such as "during statement block
1235  * local variable initialization"
1236  */
1237  errcontext("PL/pgSQL function %s line %d %s",
1238  estate->func->fn_signature,
1239  estate->err_stmt->lineno,
1240  _(estate->err_text));
1241  }
1242  else
1243  {
1244  /*
1245  * translator: last %s is a phrase such as "while storing call
1246  * arguments into local variables"
1247  */
1248  errcontext("PL/pgSQL function %s %s",
1249  estate->func->fn_signature,
1250  _(estate->err_text));
1251  }
1252  }
1253  else if (estate->err_stmt != NULL)
1254  {
1255  /* translator: last %s is a plpgsql statement type name */
1256  errcontext("PL/pgSQL function %s line %d at %s",
1257  estate->func->fn_signature,
1258  estate->err_stmt->lineno,
1259  plpgsql_stmt_typename(estate->err_stmt));
1260  }
1261  else
1262  errcontext("PL/pgSQL function %s",
1263  estate->func->fn_signature);
1264 }
1265 
1266 
1267 /* ----------
1268  * Support function for initializing local execution variables
1269  * ----------
1270  */
1271 static void
1272 copy_plpgsql_datums(PLpgSQL_execstate *estate,
1273  PLpgSQL_function *func)
1274 {
1275  int ndatums = estate->ndatums;
1276  PLpgSQL_datum **indatums;
1277  PLpgSQL_datum **outdatums;
1278  char *workspace;
1279  char *ws_next;
1280  int i;
1281 
1282  /* Allocate local datum-pointer array */
1283  estate->datums = (PLpgSQL_datum **)
1284  palloc(sizeof(PLpgSQL_datum *) * ndatums);
1285 
1286  /*
1287  * To reduce palloc overhead, we make a single palloc request for all the
1288  * space needed for locally-instantiated datums.
1289  */
1290  workspace = palloc(func->copiable_size);
1291  ws_next = workspace;
1292 
1293  /* Fill datum-pointer array, copying datums into workspace as needed */
1294  indatums = func->datums;
1295  outdatums = estate->datums;
1296  for (i = 0; i < ndatums; i++)
1297  {
1298  PLpgSQL_datum *indatum = indatums[i];
1299  PLpgSQL_datum *outdatum;
1300 
1301  /* This must agree with plpgsql_finish_datums on what is copiable */
1302  switch (indatum->dtype)
1303  {
1304  case PLPGSQL_DTYPE_VAR:
1305  case PLPGSQL_DTYPE_PROMISE:
1306  outdatum = (PLpgSQL_datum *) ws_next;
1307  memcpy(outdatum, indatum, sizeof(PLpgSQL_var));
1308  ws_next += MAXALIGN(sizeof(PLpgSQL_var));
1309  break;
1310 
1311  case PLPGSQL_DTYPE_REC:
1312  outdatum = (PLpgSQL_datum *) ws_next;
1313  memcpy(outdatum, indatum, sizeof(PLpgSQL_rec));
1314  ws_next += MAXALIGN(sizeof(PLpgSQL_rec));
1315  break;
1316 
1317  case PLPGSQL_DTYPE_ROW:
1318  case PLPGSQL_DTYPE_RECFIELD:
1319 
1320  /*
1321  * These datum records are read-only at runtime, so no need to
1322  * copy them (well, RECFIELD contains cached data, but we'd
1323  * just as soon centralize the caching anyway).
1324  */
1325  outdatum = indatum;
1326  break;
1327 
1328  default:
1329  elog(ERROR, "unrecognized dtype: %d", indatum->dtype);
1330  outdatum = NULL; /* keep compiler quiet */
1331  break;
1332  }
1333 
1334  outdatums[i] = outdatum;
1335  }
1336 
1337  Assert(ws_next == workspace + func->copiable_size);
1338 }
1339 
1340 /*
1341  * If the variable has an armed "promise", compute the promised value
1342  * and assign it to the variable.
1343  * The assignment automatically disarms the promise.
1344  */
1345 static void
1346 plpgsql_fulfill_promise(PLpgSQL_execstate *estate,
1347  PLpgSQL_var *var)
1348 {
1349  MemoryContext oldcontext;
1350 
1351  if (var->promise == PLPGSQL_PROMISE_NONE)
1352  return; /* nothing to do */
1353 
1354  /*
1355  * This will typically be invoked in a short-lived context such as the
1356  * mcontext. We must create variable values in the estate's datum
1357  * context. This quick-and-dirty solution risks leaking some additional
1358  * cruft there, but since any one promise is honored at most once per
1359  * function call, it's probably not worth being more careful.
1360  */
1361  oldcontext = MemoryContextSwitchTo(estate->datum_context);
1362 
1363  switch (var->promise)
1364  {
1365  case PLPGSQL_PROMISE_TG_NAME:
1366  if (estate->trigdata == NULL)
1367  elog(ERROR, "trigger promise is not in a trigger function");
1368  assign_simple_var(estate, var,
1369  DirectFunctionCall1(namein,
1370  CStringGetDatum(estate->trigdata->tg_trigger->tgname)),
1371  false, true);
1372  break;
1373 
1374  case PLPGSQL_PROMISE_TG_WHEN:
1375  if (estate->trigdata == NULL)
1376  elog(ERROR, "trigger promise is not in a trigger function");
1377  if (TRIGGER_FIRED_BEFORE(estate->trigdata->tg_event))
1378  assign_text_var(estate, var, "BEFORE");
1379  else if (TRIGGER_FIRED_AFTER(estate->trigdata->tg_event))
1380  assign_text_var(estate, var, "AFTER");
1381  else if (TRIGGER_FIRED_INSTEAD(estate->trigdata->tg_event))
1382  assign_text_var(estate, var, "INSTEAD OF");
1383  else
1384  elog(ERROR, "unrecognized trigger execution time: not BEFORE, AFTER, or INSTEAD OF");
1385  break;
1386 
1387  case PLPGSQL_PROMISE_TG_LEVEL:
1388  if (estate->trigdata == NULL)
1389  elog(ERROR, "trigger promise is not in a trigger function");
1390  if (TRIGGER_FIRED_FOR_ROW(estate->trigdata->tg_event))
1391  assign_text_var(estate, var, "ROW");
1392  else if (TRIGGER_FIRED_FOR_STATEMENT(estate->trigdata->tg_event))
1393  assign_text_var(estate, var, "STATEMENT");
1394  else
1395  elog(ERROR, "unrecognized trigger event type: not ROW or STATEMENT");
1396  break;
1397 
1398  case PLPGSQL_PROMISE_TG_OP:
1399  if (estate->trigdata == NULL)
1400  elog(ERROR, "trigger promise is not in a trigger function");
1401  if (TRIGGER_FIRED_BY_INSERT(estate->trigdata->tg_event))
1402  assign_text_var(estate, var, "INSERT");
1403  else if (TRIGGER_FIRED_BY_UPDATE(estate->trigdata->tg_event))
1404  assign_text_var(estate, var, "UPDATE");
1405  else if (TRIGGER_FIRED_BY_DELETE(estate->trigdata->tg_event))
1406  assign_text_var(estate, var, "DELETE");
1407  else if (TRIGGER_FIRED_BY_TRUNCATE(estate->trigdata->tg_event))
1408  assign_text_var(estate, var, "TRUNCATE");
1409  else
1410  elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, UPDATE, or TRUNCATE");
1411  break;
1412 
1413  case PLPGSQL_PROMISE_TG_RELID:
1414  if (estate->trigdata == NULL)
1415  elog(ERROR, "trigger promise is not in a trigger function");
1416  assign_simple_var(estate, var,
1417  ObjectIdGetDatum(estate->trigdata->tg_relation->rd_id),
1418  false, false);
1419  break;
1420 
1421  case PLPGSQL_PROMISE_TG_TABLE_NAME:
1422  if (estate->trigdata == NULL)
1423  elog(ERROR, "trigger promise is not in a trigger function");
1424  assign_simple_var(estate, var,
1425  DirectFunctionCall1(namein,
1426  CStringGetDatum(RelationGetRelationName(estate->trigdata->tg_relation))),
1427  false, true);
1428  break;
1429 
1430  case PLPGSQL_PROMISE_TG_TABLE_SCHEMA:
1431  if (estate->trigdata == NULL)
1432  elog(ERROR, "trigger promise is not in a trigger function");
1433  assign_simple_var(estate, var,
1434  DirectFunctionCall1(namein,
1435  CStringGetDatum(get_namespace_name(RelationGetNamespace(estate->trigdata->tg_relation)))),
1436  false, true);
1437  break;
1438 
1439  case PLPGSQL_PROMISE_TG_NARGS:
1440  if (estate->trigdata == NULL)
1441  elog(ERROR, "trigger promise is not in a trigger function");
1442  assign_simple_var(estate, var,
1443  Int16GetDatum(estate->trigdata->tg_trigger->tgnargs),
1444  false, false);
1445  break;
1446 
1447  case PLPGSQL_PROMISE_TG_ARGV:
1448  if (estate->trigdata == NULL)
1449  elog(ERROR, "trigger promise is not in a trigger function");
1450  if (estate->trigdata->tg_trigger->tgnargs > 0)
1451  {
1452  /*
1453  * For historical reasons, tg_argv[] subscripts start at zero
1454  * not one. So we can't use construct_array().
1455  */
1456  int nelems = estate->trigdata->tg_trigger->tgnargs;
1457  Datum *elems;
1458  int dims[1];
1459  int lbs[1];
1460  int i;
1461 
1462  elems = palloc(sizeof(Datum) * nelems);
1463  for (i = 0; i < nelems; i++)
1464  elems[i] = CStringGetTextDatum(estate->trigdata->tg_trigger->tgargs[i]);
1465  dims[0] = nelems;
1466  lbs[0] = 0;
1467 
1468  assign_simple_var(estate, var,
1469  PointerGetDatum(construct_md_array(elems, NULL,
1470  1, dims, lbs,
1471  TEXTOID,
1472  -1, false, TYPALIGN_INT)),
1473  false, true);
1474  }
1475  else
1476  {
1477  assign_simple_var(estate, var, (Datum) 0, true, false);
1478  }
1479  break;
1480 
1481  case PLPGSQL_PROMISE_TG_EVENT:
1482  if (estate->evtrigdata == NULL)
1483  elog(ERROR, "event trigger promise is not in an event trigger function");
1484  assign_text_var(estate, var, estate->evtrigdata->event);
1485  break;
1486 
1487  case PLPGSQL_PROMISE_TG_TAG:
1488  if (estate->evtrigdata == NULL)
1489  elog(ERROR, "event trigger promise is not in an event trigger function");
1490  assign_text_var(estate, var, GetCommandTagName(estate->evtrigdata->tag));
1491  break;
1492 
1493  default:
1494  elog(ERROR, "unrecognized promise type: %d", var->promise);
1495  }
1496 
1497  MemoryContextSwitchTo(oldcontext);
1498 }
1499 
1500 /*
1501  * Create a memory context for statement-lifespan variables, if we don't
1502  * have one already. It will be a child of stmt_mcontext_parent, which is
1503  * either the function's main context or a pushed-down outer stmt_mcontext.
1504  */
1505 static MemoryContext
1506 get_stmt_mcontext(PLpgSQL_execstate *estate)
1507 {
1508  if (estate->stmt_mcontext == NULL)
1509  {
1510  estate->stmt_mcontext =
1511  AllocSetContextCreate(estate->stmt_mcontext_parent,
1512  "PLpgSQL per-statement data",
1513  ALLOCSET_DEFAULT_SIZES);
1514  }
1515  return estate->stmt_mcontext;
1516 }
1517 
1518 /*
1519  * Push down the current stmt_mcontext so that called statements won't use it.
1520  * This is needed by statements that have statement-lifespan data and need to
1521  * preserve it across some inner statements. The caller should eventually do
1522  * pop_stmt_mcontext().
1523  */
1524 static void
1525 push_stmt_mcontext(PLpgSQL_execstate *estate)
1526 {
1527  /* Should have done get_stmt_mcontext() first */
1528  Assert(estate->stmt_mcontext != NULL);
1529  /* Assert we've not messed up the stack linkage */
1530  Assert(MemoryContextGetParent(estate->stmt_mcontext) == estate->stmt_mcontext_parent);
1531  /* Push it down to become the parent of any nested stmt mcontext */
1532  estate->stmt_mcontext_parent = estate->stmt_mcontext;
1533  /* And make it not available for use directly */
1534  estate->stmt_mcontext = NULL;
1535 }
1536 
1537 /*
1538  * Undo push_stmt_mcontext(). We assume this is done just before or after
1539  * resetting the caller's stmt_mcontext; since that action will also delete
1540  * any child contexts, there's no need to explicitly delete whatever context
1541  * might currently be estate->stmt_mcontext.
1542  */
1543 static void
1544 pop_stmt_mcontext(PLpgSQL_execstate *estate)
1545 {
1546  /* We need only pop the stack */
1547  estate->stmt_mcontext = estate->stmt_mcontext_parent;
1548  estate->stmt_mcontext_parent = MemoryContextGetParent(estate->stmt_mcontext);
1549 }
1550 
1551 
1552 /*
1553  * Subroutine for exec_stmt_block: does any condition in the condition list
1554  * match the current exception?
1555  */
1556 static bool
1557 exception_matches_conditions(ErrorData *edata, PLpgSQL_condition *cond)
1558 {
1559  for (; cond != NULL; cond = cond->next)
1560  {
1561  int sqlerrstate = cond->sqlerrstate;
1562 
1563  /*
1564  * OTHERS matches everything *except* query-canceled and
1565  * assert-failure. If you're foolish enough, you can match those
1566  * explicitly.
1567  */
1568  if (sqlerrstate == 0)
1569  {
1570  if (edata->sqlerrcode != ERRCODE_QUERY_CANCELED &&
1571  edata->sqlerrcode != ERRCODE_ASSERT_FAILURE)
1572  return true;
1573  }
1574  /* Exact match? */
1575  else if (edata->sqlerrcode == sqlerrstate)
1576  return true;
1577  /* Category match? */
1578  else if (ERRCODE_IS_CATEGORY(sqlerrstate) &&
1579  ERRCODE_TO_CATEGORY(edata->sqlerrcode) == sqlerrstate)
1580  return true;
1581  }
1582  return false;
1583 }
1584 
1585 
1586 /* ----------
1587  * exec_toplevel_block Execute the toplevel block
1588  *
1589  * This is intentionally equivalent to executing exec_stmts() with a
1590  * list consisting of the one statement. One tiny difference is that
1591  * we do not bother to save the entry value of estate->err_stmt;
1592  * that's assumed to be NULL.
1593  * ----------
1594  */
1595 static int
1596 exec_toplevel_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
1597 {
1598  int rc;
1599 
1600  estate->err_stmt = (PLpgSQL_stmt *) block;
1601 
1602  /* Let the plugin know that we are about to execute this statement */
1603  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_beg)
1604  ((*plpgsql_plugin_ptr)->stmt_beg) (estate, (PLpgSQL_stmt *) block);
1605 
1606  CHECK_FOR_INTERRUPTS();
1607 
1608  rc = exec_stmt_block(estate, block);
1609 
1610  /* Let the plugin know that we have finished executing this statement */
1611  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_end)
1612  ((*plpgsql_plugin_ptr)->stmt_end) (estate, (PLpgSQL_stmt *) block);
1613 
1614  estate->err_stmt = NULL;
1615 
1616  return rc;
1617 }
1618 
1619 
1620 /* ----------
1621  * exec_stmt_block Execute a block of statements
1622  * ----------
1623  */
1624 static int
1625 exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
1626 {
1627  volatile int rc = -1;
1628  int i;
1629 
1630  /*
1631  * First initialize all variables declared in this block
1632  */
1633  estate->err_text = gettext_noop("during statement block local variable initialization");
1634 
1635  for (i = 0; i < block->n_initvars; i++)
1636  {
1637  int n = block->initvarnos[i];
1638  PLpgSQL_datum *datum = estate->datums[n];
1639 
1640  /*
1641  * The set of dtypes handled here must match plpgsql_add_initdatums().
1642  *
1643  * Note that we currently don't support promise datums within blocks,
1644  * only at a function's outermost scope, so we needn't handle those
1645  * here.
1646  */
1647  switch (datum->dtype)
1648  {
1649  case PLPGSQL_DTYPE_VAR:
1650  {
1651  PLpgSQL_var *var = (PLpgSQL_var *) datum;
1652 
1653  /*
1654  * Free any old value, in case re-entering block, and
1655  * initialize to NULL
1656  */
1657  assign_simple_var(estate, var, (Datum) 0, true, false);
1658 
1659  if (var->default_val == NULL)
1660  {
1661  /*
1662  * If needed, give the datatype a chance to reject
1663  * NULLs, by assigning a NULL to the variable. We
1664  * claim the value is of type UNKNOWN, not the var's
1665  * datatype, else coercion will be skipped.
1666  */
1667  if (var->datatype->typtype == TYPTYPE_DOMAIN)
1668  exec_assign_value(estate,
1669  (PLpgSQL_datum *) var,
1670  (Datum) 0,
1671  true,
1672  UNKNOWNOID,
1673  -1);
1674 
1675  /* parser should have rejected NOT NULL */
1676  Assert(!var->notnull);
1677  }
1678  else
1679  {
1680  exec_assign_expr(estate, (PLpgSQL_datum *) var,
1681  var->default_val);
1682  }
1683  }
1684  break;
1685 
1686  case PLPGSQL_DTYPE_REC:
1687  {
1688  PLpgSQL_rec *rec = (PLpgSQL_rec *) datum;
1689 
1690  /*
1691  * Deletion of any existing object will be handled during
1692  * the assignments below, and in some cases it's more
1693  * efficient for us not to get rid of it beforehand.
1694  */
1695  if (rec->default_val == NULL)
1696  {
1697  /*
1698  * If needed, give the datatype a chance to reject
1699  * NULLs, by assigning a NULL to the variable.
1700  */
1701  exec_move_row(estate, (PLpgSQL_variable *) rec,
1702  NULL, NULL);
1703 
1704  /* parser should have rejected NOT NULL */
1705  Assert(!rec->notnull);
1706  }
1707  else
1708  {
1709  exec_assign_expr(estate, (PLpgSQL_datum *) rec,
1710  rec->default_val);
1711  }
1712  }
1713  break;
1714 
1715  default:
1716  elog(ERROR, "unrecognized dtype: %d", datum->dtype);
1717  }
1718  }
1719 
1720  if (block->exceptions)
1721  {
1722  /*
1723  * Execute the statements in the block's body inside a sub-transaction
1724  */
1725  MemoryContext oldcontext = CurrentMemoryContext;
1726  ResourceOwner oldowner = CurrentResourceOwner;
1727  ExprContext *old_eval_econtext = estate->eval_econtext;
1728  ErrorData *save_cur_error = estate->cur_error;
1729  MemoryContext stmt_mcontext;
1730 
1731  estate->err_text = gettext_noop("during statement block entry");
1732 
1733  /*
1734  * We will need a stmt_mcontext to hold the error data if an error
1735  * occurs. It seems best to force it to exist before entering the
1736  * subtransaction, so that we reduce the risk of out-of-memory during
1737  * error recovery, and because this greatly simplifies restoring the
1738  * stmt_mcontext stack to the correct state after an error. We can
1739  * ameliorate the cost of this by allowing the called statements to
1740  * use this mcontext too; so we don't push it down here.
1741  */
1742  stmt_mcontext = get_stmt_mcontext(estate);
1743 
1744  BeginInternalSubTransaction(NULL);
1745  /* Want to run statements inside function's memory context */
1746  MemoryContextSwitchTo(oldcontext);
1747 
1748  PG_TRY();
1749  {
1750  /*
1751  * We need to run the block's statements with a new eval_econtext
1752  * that belongs to the current subtransaction; if we try to use
1753  * the outer econtext then ExprContext shutdown callbacks will be
1754  * called at the wrong times.
1755  */
1756  plpgsql_create_econtext(estate);
1757 
1758  estate->err_text = NULL;
1759 
1760  /* Run the block's statements */
1761  rc = exec_stmts(estate, block->body);
1762 
1763  estate->err_text = gettext_noop("during statement block exit");
1764 
1765  /*
1766  * If the block ended with RETURN, we may need to copy the return
1767  * value out of the subtransaction eval_context. We can avoid a
1768  * physical copy if the value happens to be a R/W expanded object.
1769  */
1770  if (rc == PLPGSQL_RC_RETURN &&
1771  !estate->retisset &&
1772  !estate->retisnull)
1773  {
1774  int16 resTypLen;
1775  bool resTypByVal;
1776 
1777  get_typlenbyval(estate->rettype, &resTypLen, &resTypByVal);
1778  estate->retval = datumTransfer(estate->retval,
1779  resTypByVal, resTypLen);
1780  }
1781 
1782  /* Commit the inner transaction, return to outer xact context */
1783  ReleaseCurrentSubTransaction();
1784  MemoryContextSwitchTo(oldcontext);
1785  CurrentResourceOwner = oldowner;
1786 
1787  /* Assert that the stmt_mcontext stack is unchanged */
1788  Assert(stmt_mcontext == estate->stmt_mcontext);
1789 
1790  /*
1791  * Revert to outer eval_econtext. (The inner one was
1792  * automatically cleaned up during subxact exit.)
1793  */
1794  estate->eval_econtext = old_eval_econtext;
1795  }
1796  PG_CATCH();
1797  {
1798  ErrorData *edata;
1799  ListCell *e;
1800 
1801  estate->err_text = gettext_noop("during exception cleanup");
1802 
1803  /* Save error info in our stmt_mcontext */
1804  MemoryContextSwitchTo(stmt_mcontext);
1805  edata = CopyErrorData();
1806  FlushErrorState();
1807 
1808  /* Abort the inner transaction */
1809  RollbackAndReleaseCurrentSubTransaction();
1810  MemoryContextSwitchTo(oldcontext);
1811  CurrentResourceOwner = oldowner;
1812 
1813  /*
1814  * Set up the stmt_mcontext stack as though we had restored our
1815  * previous state and then done push_stmt_mcontext(). The push is
1816  * needed so that statements in the exception handler won't
1817  * clobber the error data that's in our stmt_mcontext.
1818  */
1819  estate->stmt_mcontext_parent = stmt_mcontext;
1820  estate->stmt_mcontext = NULL;
1821 
1822  /*
1823  * Now we can delete any nested stmt_mcontexts that might have
1824  * been created as children of ours. (Note: we do not immediately
1825  * release any statement-lifespan data that might have been left
1826  * behind in stmt_mcontext itself. We could attempt that by doing
1827  * a MemoryContextReset on it before collecting the error data
1828  * above, but it seems too risky to do any significant amount of
1829  * work before collecting the error.)
1830  */
1831  MemoryContextDeleteChildren(stmt_mcontext);
1832 
1833  /* Revert to outer eval_econtext */
1834  estate->eval_econtext = old_eval_econtext;
1835 
1836  /*
1837  * Must clean up the econtext too. However, any tuple table made
1838  * in the subxact will have been thrown away by SPI during subxact
1839  * abort, so we don't need to (and mustn't try to) free the
1840  * eval_tuptable.
1841  */
1842  estate->eval_tuptable = NULL;
1843  exec_eval_cleanup(estate);
1844 
1845  /* Look for a matching exception handler */
1846  foreach(e, block->exceptions->exc_list)
1847  {
1848  PLpgSQL_exception *exception = (PLpgSQL_exception *) lfirst(e);
1849 
1850  if (exception_matches_conditions(edata, exception->conditions))
1851  {
1852  /*
1853  * Initialize the magic SQLSTATE and SQLERRM variables for
1854  * the exception block; this also frees values from any
1855  * prior use of the same exception. We needn't do this
1856  * until we have found a matching exception.
1857  */
1858  PLpgSQL_var *state_var;
1859  PLpgSQL_var *errm_var;
1860 
1861  state_var = (PLpgSQL_var *)
1862  estate->datums[block->exceptions->sqlstate_varno];
1863  errm_var = (PLpgSQL_var *)
1864  estate->datums[block->exceptions->sqlerrm_varno];
1865 
1866  assign_text_var(estate, state_var,
1867  unpack_sql_state(edata->sqlerrcode));
1868  assign_text_var(estate, errm_var, edata->message);
1869 
1870  /*
1871  * Also set up cur_error so the error data is accessible
1872  * inside the handler.
1873  */
1874  estate->cur_error = edata;
1875 
1876  estate->err_text = NULL;
1877 
1878  rc = exec_stmts(estate, exception->action);
1879 
1880  break;
1881  }
1882  }
1883 
1884  /*
1885  * Restore previous state of cur_error, whether or not we executed
1886  * a handler. This is needed in case an error got thrown from
1887  * some inner block's exception handler.
1888  */
1889  estate->cur_error = save_cur_error;
1890 
1891  /* If no match found, re-throw the error */
1892  if (e == NULL)
1893  ReThrowError(edata);
1894 
1895  /* Restore stmt_mcontext stack and release the error data */
1896  pop_stmt_mcontext(estate);
1897  MemoryContextReset(stmt_mcontext);
1898  }
1899  PG_END_TRY();
1900 
1901  Assert(save_cur_error == estate->cur_error);
1902  }
1903  else
1904  {
1905  /*
1906  * Just execute the statements in the block's body
1907  */
1908  estate->err_text = NULL;
1909 
1910  rc = exec_stmts(estate, block->body);
1911  }
1912 
1913  estate->err_text = NULL;
1914 
1915  /*
1916  * Handle the return code. This is intentionally different from
1917  * LOOP_RC_PROCESSING(): CONTINUE never matches a block, and EXIT matches
1918  * a block only if there is a label match.
1919  */
1920  switch (rc)
1921  {
1922  case PLPGSQL_RC_OK:
1923  case PLPGSQL_RC_RETURN:
1924  case PLPGSQL_RC_CONTINUE:
1925  return rc;
1926 
1927  case PLPGSQL_RC_EXIT:
1928  if (estate->exitlabel == NULL)
1929  return PLPGSQL_RC_EXIT;
1930  if (block->label == NULL)
1931  return PLPGSQL_RC_EXIT;
1932  if (strcmp(block->label, estate->exitlabel) != 0)
1933  return PLPGSQL_RC_EXIT;
1934  estate->exitlabel = NULL;
1935  return PLPGSQL_RC_OK;
1936 
1937  default:
1938  elog(ERROR, "unrecognized rc: %d", rc);
1939  }
1940 
1941  return PLPGSQL_RC_OK;
1942 }
1943 
1944 
1945 /* ----------
1946  * exec_stmts Iterate over a list of statements
1947  * as long as their return code is OK
1948  * ----------
1949  */
1950 static int
1951 exec_stmts(PLpgSQL_execstate *estate, List *stmts)
1952 {
1953  PLpgSQL_stmt *save_estmt = estate->err_stmt;
1954  ListCell *s;
1955 
1956  if (stmts == NIL)
1957  {
1958  /*
1959  * Ensure we do a CHECK_FOR_INTERRUPTS() even though there is no
1960  * statement. This prevents hangup in a tight loop if, for instance,
1961  * there is a LOOP construct with an empty body.
1962  */
1963  CHECK_FOR_INTERRUPTS();
1964  return PLPGSQL_RC_OK;
1965  }
1966 
1967  foreach(s, stmts)
1968  {
1969  PLpgSQL_stmt *stmt = (PLpgSQL_stmt *) lfirst(s);
1970  int rc;
1971 
1972  estate->err_stmt = stmt;
1973 
1974  /* Let the plugin know that we are about to execute this statement */
1975  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_beg)
1976  ((*plpgsql_plugin_ptr)->stmt_beg) (estate, stmt);
1977 
1978  CHECK_FOR_INTERRUPTS();
1979 
1980  switch (stmt->cmd_type)
1981  {
1982  case PLPGSQL_STMT_BLOCK:
1983  rc = exec_stmt_block(estate, (PLpgSQL_stmt_block *) stmt);
1984  break;
1985 
1986  case PLPGSQL_STMT_ASSIGN:
1987  rc = exec_stmt_assign(estate, (PLpgSQL_stmt_assign *) stmt);
1988  break;
1989 
1990  case PLPGSQL_STMT_PERFORM:
1991  rc = exec_stmt_perform(estate, (PLpgSQL_stmt_perform *) stmt);
1992  break;
1993 
1994  case PLPGSQL_STMT_CALL:
1995  rc = exec_stmt_call(estate, (PLpgSQL_stmt_call *) stmt);
1996  break;
1997 
1998  case PLPGSQL_STMT_GETDIAG:
1999  rc = exec_stmt_getdiag(estate, (PLpgSQL_stmt_getdiag *) stmt);
2000  break;
2001 
2002  case PLPGSQL_STMT_IF:
2003  rc = exec_stmt_if(estate, (PLpgSQL_stmt_if *) stmt);
2004  break;
2005 
2006  case PLPGSQL_STMT_CASE:
2007  rc = exec_stmt_case(estate, (PLpgSQL_stmt_case *) stmt);
2008  break;
2009 
2010  case PLPGSQL_STMT_LOOP:
2011  rc = exec_stmt_loop(estate, (PLpgSQL_stmt_loop *) stmt);
2012  break;
2013 
2014  case PLPGSQL_STMT_WHILE:
2015  rc = exec_stmt_while(estate, (PLpgSQL_stmt_while *) stmt);
2016  break;
2017 
2018  case PLPGSQL_STMT_FORI:
2019  rc = exec_stmt_fori(estate, (PLpgSQL_stmt_fori *) stmt);
2020  break;
2021 
2022  case PLPGSQL_STMT_FORS:
2023  rc = exec_stmt_fors(estate, (PLpgSQL_stmt_fors *) stmt);
2024  break;
2025 
2026  case PLPGSQL_STMT_FORC:
2027  rc = exec_stmt_forc(estate, (PLpgSQL_stmt_forc *) stmt);
2028  break;
2029 
2030  case PLPGSQL_STMT_FOREACH_A:
2031  rc = exec_stmt_foreach_a(estate, (PLpgSQL_stmt_foreach_a *) stmt);
2032  break;
2033 
2034  case PLPGSQL_STMT_EXIT:
2035  rc = exec_stmt_exit(estate, (PLpgSQL_stmt_exit *) stmt);
2036  break;
2037 
2038  case PLPGSQL_STMT_RETURN:
2039  rc = exec_stmt_return(estate, (PLpgSQL_stmt_return *) stmt);
2040  break;
2041 
2042  case PLPGSQL_STMT_RETURN_NEXT:
2043  rc = exec_stmt_return_next(estate, (PLpgSQL_stmt_return_next *) stmt);
2044  break;
2045 
2046  case PLPGSQL_STMT_RETURN_QUERY:
2047  rc = exec_stmt_return_query(estate, (PLpgSQL_stmt_return_query *) stmt);
2048  break;
2049 
2050  case PLPGSQL_STMT_RAISE:
2051  rc = exec_stmt_raise(estate, (PLpgSQL_stmt_raise *) stmt);
2052  break;
2053 
2054  case PLPGSQL_STMT_ASSERT:
2055  rc = exec_stmt_assert(estate, (PLpgSQL_stmt_assert *) stmt);
2056  break;
2057 
2058  case PLPGSQL_STMT_EXECSQL:
2059  rc = exec_stmt_execsql(estate, (PLpgSQL_stmt_execsql *) stmt);
2060  break;
2061 
2062  case PLPGSQL_STMT_DYNEXECUTE:
2063  rc = exec_stmt_dynexecute(estate, (PLpgSQL_stmt_dynexecute *) stmt);
2064  break;
2065 
2066  case PLPGSQL_STMT_DYNFORS:
2067  rc = exec_stmt_dynfors(estate, (PLpgSQL_stmt_dynfors *) stmt);
2068  break;
2069 
2070  case PLPGSQL_STMT_OPEN:
2071  rc = exec_stmt_open(estate, (PLpgSQL_stmt_open *) stmt);
2072  break;
2073 
2074  case PLPGSQL_STMT_FETCH:
2075  rc = exec_stmt_fetch(estate, (PLpgSQL_stmt_fetch *) stmt);
2076  break;
2077 
2078  case PLPGSQL_STMT_CLOSE:
2079  rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
2080  break;
2081 
2082  case PLPGSQL_STMT_COMMIT:
2083  rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
2084  break;
2085 
2086  case PLPGSQL_STMT_ROLLBACK:
2087  rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
2088  break;
2089 
2090  default:
2091  /* point err_stmt to parent, since this one seems corrupt */
2092  estate->err_stmt = save_estmt;
2093  elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
2094  rc = -1; /* keep compiler quiet */
2095  }
2096 
2097  /* Let the plugin know that we have finished executing this statement */
2098  if (*plpgsql_plugin_ptr && (*plpgsql_plugin_ptr)->stmt_end)
2099  ((*plpgsql_plugin_ptr)->stmt_end) (estate, stmt);
2100 
2101  if (rc != PLPGSQL_RC_OK)
2102  {
2103  estate->err_stmt = save_estmt;
2104  return rc;
2105  }
2106  } /* end of loop over statements */
2107 
2108  estate->err_stmt = save_estmt;
2109  return PLPGSQL_RC_OK;
2110 }
2111 
2112 
2113 /* ----------
2114  * exec_stmt_assign Evaluate an expression and
2115  * put the result into a variable.
2116  * ----------
2117  */
2118 static int
2119 exec_stmt_assign(PLpgSQL_execstate *estate, PLpgSQL_stmt_assign *stmt)
2120 {
2121  Assert(stmt->varno >= 0);
2122 
2123  exec_assign_expr(estate, estate->datums[stmt->varno], stmt->expr);
2124 
2125  return PLPGSQL_RC_OK;
2126 }
2127 
2128 /* ----------
2129  * exec_stmt_perform Evaluate query and discard result (but set
2130  * FOUND depending on whether at least one row
2131  * was returned).
2132  * ----------
2133  */
2134 static int
2135 exec_stmt_perform(PLpgSQL_execstate *estate, PLpgSQL_stmt_perform *stmt)
2136 {
2137  PLpgSQL_expr *expr = stmt->expr;
2138 
2139  (void) exec_run_select(estate, expr, 0, NULL);
2140  exec_set_found(estate, (estate->eval_processed != 0));
2141  exec_eval_cleanup(estate);
2142 
2143  return PLPGSQL_RC_OK;
2144 }
2145 
2146 /*
2147  * exec_stmt_call
2148  *
2149  * NOTE: this is used for both CALL and DO statements.
2150  */
2151 static int
2152 exec_stmt_call(PLpgSQL_execstate *estate, PLpgSQL_stmt_call *stmt)
2153 {
2154  PLpgSQL_expr *expr = stmt->expr;
2155  LocalTransactionId before_lxid;
2156  LocalTransactionId after_lxid;
2157  ParamListInfo paramLI;
2158  SPIExecuteOptions options;
2159  int rc;
2160 
2161  /*
2162  * Make a plan if we don't have one already.
2163  */
2164  if (expr->plan == NULL)
2165  exec_prepare_plan(estate, expr, 0);
2166 
2167  /*
2168  * A CALL or DO can never be a simple expression.
2169  */
2170  Assert(!expr->expr_simple_expr);
2171 
2172  /*
2173  * Also construct a DTYPE_ROW datum representing the plpgsql variables
2174  * associated with the procedure's output arguments. Then we can use
2175  * exec_move_row() to do the assignments.
2176  */
2177  if (stmt->is_call && stmt->target == NULL)
2178  stmt->target = make_callstmt_target(estate, expr);
2179 
2180  paramLI = setup_param_list(estate, expr);
2181 
2182  before_lxid = MyProc->lxid;
2183 
2184  /*
2185  * If we have a procedure-lifespan resowner, use that to hold the refcount
2186  * for the plan. This avoids refcount leakage complaints if the called
2187  * procedure ends the current transaction.
2188  *
2189  * Also, tell SPI to allow non-atomic execution.
2190  */
2191  memset(&options, 0, sizeof(options));
2192  options.params = paramLI;
2193  options.read_only = estate->readonly_func;
2194  options.allow_nonatomic = true;
2195  options.owner = estate->procedure_resowner;
2196 
2197  rc = SPI_execute_plan_extended(expr->plan, &options);
2198 
2199  if (rc < 0)
2200  elog(ERROR, "SPI_execute_plan_extended failed executing query \"%s\": %s",
2201  expr->query, SPI_result_code_string(rc));
2202 
2203  after_lxid = MyProc->lxid;
2204 
2205  if (before_lxid != after_lxid)
2206  {
2207  /*
2208  * If we are in a new transaction after the call, we need to build new
2209  * simple-expression infrastructure.
2210  */
2211  estate->simple_eval_estate = NULL;
2212  estate->simple_eval_resowner = NULL;
2213  plpgsql_create_econtext(estate);
2214  }
2215 
2216  /*
2217  * Check result rowcount; if there's one row, assign procedure's output
2218  * values back to the appropriate variables.
2219  */
2220  if (SPI_processed == 1)
2221  {
2222  SPITupleTable *tuptab = SPI_tuptable;
2223 
2224  if (!stmt->is_call)
2225  elog(ERROR, "DO statement returned a row");
2226 
2227  exec_move_row(estate, stmt->target, tuptab->vals[0], tuptab->tupdesc);
2228  }
2229  else if (SPI_processed > 1)
2230  elog(ERROR, "procedure call returned more than one row");
2231 
2232  exec_eval_cleanup(estate);
2233  SPI_freetuptable(SPI_tuptable);
2234 
2235  return PLPGSQL_RC_OK;
2236 }
2237 
2238 /*
2239  * We construct a DTYPE_ROW datum representing the plpgsql variables
2240  * associated with the procedure's output arguments. Then we can use
2241  * exec_move_row() to do the assignments.
2242  */
2243 static PLpgSQL_variable *
2244 make_callstmt_target(PLpgSQL_execstate *estate, PLpgSQL_expr *expr)
2245 {
2246  List *plansources;
2247  CachedPlanSource *plansource;
2248  CallStmt *stmt;
2249  FuncExpr *funcexpr;
2250  HeapTuple func_tuple;
2251  Oid *argtypes;
2252  char **argnames;
2253  char *argmodes;
2254  int numargs;
2255  MemoryContext oldcontext;
2256  PLpgSQL_row *row;
2257  int nfields;
2258  int i;
2259 
2260  /* Use eval_mcontext for any cruft accumulated here */
2261  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
2262 
2263  /*
2264  * Get the parsed CallStmt, and look up the called procedure
2265  */
2266  plansources = SPI_plan_get_plan_sources(expr->plan);
2267  if (list_length(plansources) != 1)
2268  elog(ERROR, "query for CALL statement is not a CallStmt");
2269  plansource = (CachedPlanSource *) linitial(plansources);
2270  if (list_length(plansource->query_list) != 1)
2271  elog(ERROR, "query for CALL statement is not a CallStmt");
2272  stmt = (CallStmt *) linitial_node(Query,
2273  plansource->query_list)->utilityStmt;
2274  if (stmt == NULL || !IsA(stmt, CallStmt))
2275  elog(ERROR, "query for CALL statement is not a CallStmt");
2276 
2277  funcexpr = stmt->funcexpr;
2278 
2279  func_tuple = SearchSysCache1(PROCOID,
2280  ObjectIdGetDatum(funcexpr->funcid));
2281  if (!HeapTupleIsValid(func_tuple))
2282  elog(ERROR, "cache lookup failed for function %u",
2283  funcexpr->funcid);
2284 
2285  /*
2286  * Get the argument names and modes, so that we can deliver on-point error
2287  * messages when something is wrong.
2288  */
2289  numargs = get_func_arg_info(func_tuple, &argtypes, &argnames, &argmodes);
2290 
2291  ReleaseSysCache(func_tuple);
2292 
2293  /*
2294  * Begin constructing row Datum; keep it in fn_cxt so it's adequately
2295  * long-lived.
2296  */
2297  MemoryContextSwitchTo(estate->func->fn_cxt);
2298 
2299  row = (PLpgSQL_row *) palloc0(sizeof(PLpgSQL_row));
2300  row->dtype = PLPGSQL_DTYPE_ROW;
2301  row->refname = "(unnamed row)";
2302  row->lineno = -1;
2303  row->varnos = (int *) palloc(numargs * sizeof(int));
2304 
2305  MemoryContextSwitchTo(get_eval_mcontext(estate));
2306 
2307  /*
2308  * Examine procedure's argument list. Each output arg position should be
2309  * an unadorned plpgsql variable (Datum), which we can insert into the row
2310  * Datum.
2311  */
2312  nfields = 0;
2313  for (i = 0; i < numargs; i++)
2314  {
2315  if (argmodes &&
2316  (argmodes[i] == PROARGMODE_INOUT ||
2317  argmodes[i] == PROARGMODE_OUT))
2318  {
2319  Node *n = list_nth(stmt->outargs, nfields);
2320 
2321  if (IsA(n, Param))
2322  {
2323  Param *param = (Param *) n;
2324 
2325  /* paramid is offset by 1 (see make_datum_param()) */
2326  row->varnos[nfields++] = param->paramid - 1;
2327  }
2328  else
2329  {
2330  /* report error using parameter name, if available */
2331  if (argnames && argnames[i] && argnames[i][0])
2332  ereport(ERROR,
2333  (errcode(ERRCODE_SYNTAX_ERROR),
2334  errmsg("procedure parameter \"%s\" is an output parameter but corresponding argument is not writable",
2335  argnames[i])));
2336  else
2337  ereport(ERROR,
2338  (errcode(ERRCODE_SYNTAX_ERROR),
2339  errmsg("procedure parameter %d is an output parameter but corresponding argument is not writable",
2340  i + 1)));
2341  }
2342  }
2343  }
2344 
2345  Assert(nfields == list_length(stmt->outargs));
2346 
2347  row->nfields = nfields;
2348 
2349  MemoryContextSwitchTo(oldcontext);
2350 
2351  return (PLpgSQL_variable *) row;
2352 }
2353 
2354 /* ----------
2355  * exec_stmt_getdiag Put internal PG information into
2356  * specified variables.
2357  * ----------
2358  */
2359 static int
2360 exec_stmt_getdiag(PLpgSQL_execstate *estate, PLpgSQL_stmt_getdiag *stmt)
2361 {
2362  ListCell *lc;
2363 
2364  /*
2365  * GET STACKED DIAGNOSTICS is only valid inside an exception handler.
2366  *
2367  * Note: we trust the grammar to have disallowed the relevant item kinds
2368  * if not is_stacked, otherwise we'd dump core below.
2369  */
2370  if (stmt->is_stacked && estate->cur_error == NULL)
2371  ereport(ERROR,
2372  (errcode(ERRCODE_STACKED_DIAGNOSTICS_ACCESSED_WITHOUT_ACTIVE_HANDLER),
2373  errmsg("GET STACKED DIAGNOSTICS cannot be used outside an exception handler")));
2374 
2375  foreach(lc, stmt->diag_items)
2376  {
2377  PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc);
2378  PLpgSQL_datum *var = estate->datums[diag_item->target];
2379 
2380  switch (diag_item->kind)
2381  {
2382  case PLPGSQL_GETDIAG_ROW_COUNT:
2383  exec_assign_value(estate, var,
2384  UInt64GetDatum(estate->eval_processed),
2385  false, INT8OID, -1);
2386  break;
2387 
2388  case PLPGSQL_GETDIAG_ERROR_CONTEXT:
2389  exec_assign_c_string(estate, var,
2390  estate->cur_error->context);
2391  break;
2392 
2393  case PLPGSQL_GETDIAG_ERROR_DETAIL:
2394  exec_assign_c_string(estate, var,
2395  estate->cur_error->detail);
2396  break;
2397 
2398  case PLPGSQL_GETDIAG_ERROR_HINT:
2399  exec_assign_c_string(estate, var,
2400  estate->cur_error->hint);
2401  break;
2402 
2403  case PLPGSQL_GETDIAG_RETURNED_SQLSTATE:
2404  exec_assign_c_string(estate, var,
2405  unpack_sql_state(estate->cur_error->sqlerrcode));
2406  break;
2407 
2408  case PLPGSQL_GETDIAG_COLUMN_NAME:
2409  exec_assign_c_string(estate, var,
2410  estate->cur_error->column_name);
2411  break;
2412 
2413  case PLPGSQL_GETDIAG_CONSTRAINT_NAME:
2414  exec_assign_c_string(estate, var,
2415  estate->cur_error->constraint_name);
2416  break;
2417 
2418  case PLPGSQL_GETDIAG_DATATYPE_NAME:
2419  exec_assign_c_string(estate, var,
2420  estate->cur_error->datatype_name);
2421  break;
2422 
2423  case PLPGSQL_GETDIAG_MESSAGE_TEXT:
2424  exec_assign_c_string(estate, var,
2425  estate->cur_error->message);
2426  break;
2427 
2428  case PLPGSQL_GETDIAG_TABLE_NAME:
2429  exec_assign_c_string(estate, var,
2430  estate->cur_error->table_name);
2431  break;
2432 
2433  case PLPGSQL_GETDIAG_SCHEMA_NAME:
2434  exec_assign_c_string(estate, var,
2435  estate->cur_error->schema_name);
2436  break;
2437 
2438  case PLPGSQL_GETDIAG_CONTEXT:
2439  {
2440  char *contextstackstr;
2441  MemoryContext oldcontext;
2442 
2443  /* Use eval_mcontext for short-lived string */
2444  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
2445  contextstackstr = GetErrorContextStack();
2446  MemoryContextSwitchTo(oldcontext);
2447 
2448  exec_assign_c_string(estate, var, contextstackstr);
2449  }
2450  break;
2451 
2452  default:
2453  elog(ERROR, "unrecognized diagnostic item kind: %d",
2454  diag_item->kind);
2455  }
2456  }
2457 
2458  exec_eval_cleanup(estate);
2459 
2460  return PLPGSQL_RC_OK;
2461 }
2462 
2463 /* ----------
2464  * exec_stmt_if Evaluate a bool expression and
2465  * execute the true or false body
2466  * conditionally.
2467  * ----------
2468  */
2469 static int
2470 exec_stmt_if(PLpgSQL_execstate *estate, PLpgSQL_stmt_if *stmt)
2471 {
2472  bool value;
2473  bool isnull;
2474  ListCell *lc;
2475 
2476  value = exec_eval_boolean(estate, stmt->cond, &isnull);
2477  exec_eval_cleanup(estate);
2478  if (!isnull && value)
2479  return exec_stmts(estate, stmt->then_body);
2480 
2481  foreach(lc, stmt->elsif_list)
2482  {
2483  PLpgSQL_if_elsif *elif = (PLpgSQL_if_elsif *) lfirst(lc);
2484 
2485  value = exec_eval_boolean(estate, elif->cond, &isnull);
2486  exec_eval_cleanup(estate);
2487  if (!isnull && value)
2488  return exec_stmts(estate, elif->stmts);
2489  }
2490 
2491  return exec_stmts(estate, stmt->else_body);
2492 }
2493 
2494 
2495 /*-----------
2496  * exec_stmt_case
2497  *-----------
2498  */
2499 static int
2500 exec_stmt_case(PLpgSQL_execstate *estate, PLpgSQL_stmt_case *stmt)
2501 {
2502  PLpgSQL_var *t_var = NULL;
2503  bool isnull;
2504  ListCell *l;
2505 
2506  if (stmt->t_expr != NULL)
2507  {
2508  /* simple case */
2509  Datum t_val;
2510  Oid t_typoid;
2511  int32 t_typmod;
2512 
2513  t_val = exec_eval_expr(estate, stmt->t_expr,
2514  &isnull, &t_typoid, &t_typmod);
2515 
2516  t_var = (PLpgSQL_var *) estate->datums[stmt->t_varno];
2517 
2518  /*
2519  * When expected datatype is different from real, change it. Note that
2520  * what we're modifying here is an execution copy of the datum, so
2521  * this doesn't affect the originally stored function parse tree. (In
2522  * theory, if the expression datatype keeps changing during execution,
2523  * this could cause a function-lifespan memory leak. Doesn't seem
2524  * worth worrying about though.)
2525  */
2526  if (t_var->datatype->typoid != t_typoid ||
2527  t_var->datatype->atttypmod != t_typmod)
2528  t_var->datatype = plpgsql_build_datatype(t_typoid,
2529  t_typmod,
2530  estate->func->fn_input_collation,
2531  NULL);
2532 
2533  /* now we can assign to the variable */
2534  exec_assign_value(estate,
2535  (PLpgSQL_datum *) t_var,
2536  t_val,
2537  isnull,
2538  t_typoid,
2539  t_typmod);
2540 
2541  exec_eval_cleanup(estate);
2542  }
2543 
2544  /* Now search for a successful WHEN clause */
2545  foreach(l, stmt->case_when_list)
2546  {
2547  PLpgSQL_case_when *cwt = (PLpgSQL_case_when *) lfirst(l);
2548  bool value;
2549 
2550  value = exec_eval_boolean(estate, cwt->expr, &isnull);
2551  exec_eval_cleanup(estate);
2552  if (!isnull && value)
2553  {
2554  /* Found it */
2555 
2556  /* We can now discard any value we had for the temp variable */
2557  if (t_var != NULL)
2558  assign_simple_var(estate, t_var, (Datum) 0, true, false);
2559 
2560  /* Evaluate the statement(s), and we're done */
2561  return exec_stmts(estate, cwt->stmts);
2562  }
2563  }
2564 
2565  /* We can now discard any value we had for the temp variable */
2566  if (t_var != NULL)
2567  assign_simple_var(estate, t_var, (Datum) 0, true, false);
2568 
2569  /* SQL2003 mandates this error if there was no ELSE clause */
2570  if (!stmt->have_else)
2571  ereport(ERROR,
2572  (errcode(ERRCODE_CASE_NOT_FOUND),
2573  errmsg("case not found"),
2574  errhint("CASE statement is missing ELSE part.")));
2575 
2576  /* Evaluate the ELSE statements, and we're done */
2577  return exec_stmts(estate, stmt->else_stmts);
2578 }
2579 
2580 
2581 /* ----------
2582  * exec_stmt_loop Loop over statements until
2583  * an exit occurs.
2584  * ----------
2585  */
2586 static int
2587 exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt)
2588 {
2589  int rc = PLPGSQL_RC_OK;
2590 
2591  for (;;)
2592  {
2593  rc = exec_stmts(estate, stmt->body);
2594 
2595  LOOP_RC_PROCESSING(stmt->label, break);
2596  }
2597 
2598  return rc;
2599 }
2600 
2601 
2602 /* ----------
2603  * exec_stmt_while Loop over statements as long
2604  * as an expression evaluates to
2605  * true or an exit occurs.
2606  * ----------
2607  */
2608 static int
2609 exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt)
2610 {
2611  int rc = PLPGSQL_RC_OK;
2612 
2613  for (;;)
2614  {
2615  bool value;
2616  bool isnull;
2617 
2618  value = exec_eval_boolean(estate, stmt->cond, &isnull);
2619  exec_eval_cleanup(estate);
2620 
2621  if (isnull || !value)
2622  break;
2623 
2624  rc = exec_stmts(estate, stmt->body);
2625 
2626  LOOP_RC_PROCESSING(stmt->label, break);
2627  }
2628 
2629  return rc;
2630 }
2631 
2632 
2633 /* ----------
2634  * exec_stmt_fori Iterate an integer variable
2635  * from a lower to an upper value
2636  * incrementing or decrementing by the BY value
2637  * ----------
2638  */
2639 static int
2640 exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt)
2641 {
2642  PLpgSQL_var *var;
2643  Datum value;
2644  bool isnull;
2645  Oid valtype;
2646  int32 valtypmod;
2647  int32 loop_value;
2648  int32 end_value;
2649  int32 step_value;
2650  bool found = false;
2651  int rc = PLPGSQL_RC_OK;
2652 
2653  var = (PLpgSQL_var *) (estate->datums[stmt->var->dno]);
2654 
2655  /*
2656  * Get the value of the lower bound
2657  */
2658  value = exec_eval_expr(estate, stmt->lower,
2659  &isnull, &valtype, &valtypmod);
2660  value = exec_cast_value(estate, value, &isnull,
2661  valtype, valtypmod,
2662  var->datatype->typoid,
2663  var->datatype->atttypmod);
2664  if (isnull)
2665  ereport(ERROR,
2666  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
2667  errmsg("lower bound of FOR loop cannot be null")));
2668  loop_value = DatumGetInt32(value);
2669  exec_eval_cleanup(estate);
2670 
2671  /*
2672  * Get the value of the upper bound
2673  */
2674  value = exec_eval_expr(estate, stmt->upper,
2675  &isnull, &valtype, &valtypmod);
2676  value = exec_cast_value(estate, value, &isnull,
2677  valtype, valtypmod,
2678  var->datatype->typoid,
2679  var->datatype->atttypmod);
2680  if (isnull)
2681  ereport(ERROR,
2682  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
2683  errmsg("upper bound of FOR loop cannot be null")));
2684  end_value = DatumGetInt32(value);
2685  exec_eval_cleanup(estate);
2686 
2687  /*
2688  * Get the step value
2689  */
2690  if (stmt->step)
2691  {
2692  value = exec_eval_expr(estate, stmt->step,
2693  &isnull, &valtype, &valtypmod);
2694  value = exec_cast_value(estate, value, &isnull,
2695  valtype, valtypmod,
2696  var->datatype->typoid,
2697  var->datatype->atttypmod);
2698  if (isnull)
2699  ereport(ERROR,
2700  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
2701  errmsg("BY value of FOR loop cannot be null")));
2702  step_value = DatumGetInt32(value);
2703  exec_eval_cleanup(estate);
2704  if (step_value <= 0)
2705  ereport(ERROR,
2706  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2707  errmsg("BY value of FOR loop must be greater than zero")));
2708  }
2709  else
2710  step_value = 1;
2711 
2712  /*
2713  * Now do the loop
2714  */
2715  for (;;)
2716  {
2717  /*
2718  * Check against upper bound
2719  */
2720  if (stmt->reverse)
2721  {
2722  if (loop_value < end_value)
2723  break;
2724  }
2725  else
2726  {
2727  if (loop_value > end_value)
2728  break;
2729  }
2730 
2731  found = true; /* looped at least once */
2732 
2733  /*
2734  * Assign current value to loop var
2735  */
2736  assign_simple_var(estate, var, Int32GetDatum(loop_value), false, false);
2737 
2738  /*
2739  * Execute the statements
2740  */
2741  rc = exec_stmts(estate, stmt->body);
2742 
2743  LOOP_RC_PROCESSING(stmt->label, break);
2744 
2745  /*
2746  * Increase/decrease loop value, unless it would overflow, in which
2747  * case exit the loop.
2748  */
2749  if (stmt->reverse)
2750  {
2751  if (loop_value < (PG_INT32_MIN + step_value))
2752  break;
2753  loop_value -= step_value;
2754  }
2755  else
2756  {
2757  if (loop_value > (PG_INT32_MAX - step_value))
2758  break;
2759  loop_value += step_value;
2760  }
2761  }
2762 
2763  /*
2764  * Set the FOUND variable to indicate the result of executing the loop
2765  * (namely, whether we looped one or more times). This must be set here so
2766  * that it does not interfere with the value of the FOUND variable inside
2767  * the loop processing itself.
2768  */
2769  exec_set_found(estate, found);
2770 
2771  return rc;
2772 }
2773 
2774 
2775 /* ----------
2776  * exec_stmt_fors Execute a query, assign each
2777  * tuple to a record or row and
2778  * execute a group of statements
2779  * for it.
2780  * ----------
2781  */
2782 static int
2783 exec_stmt_fors(PLpgSQL_execstate *estate, PLpgSQL_stmt_fors *stmt)
2784 {
2785  Portal portal;
2786  int rc;
2787 
2788  /*
2789  * Open the implicit cursor for the statement using exec_run_select
2790  */
2791  exec_run_select(estate, stmt->query, 0, &portal);
2792 
2793  /*
2794  * Execute the loop
2795  */
2796  rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, true);
2797 
2798  /*
2799  * Close the implicit cursor
2800  */
2801  SPI_cursor_close(portal);
2802 
2803  return rc;
2804 }
2805 
2806 
2807 /* ----------
2808  * exec_stmt_forc Execute a loop for each row from a cursor.
2809  * ----------
2810  */
2811 static int
2812 exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt)
2813 {
2814  PLpgSQL_var *curvar;
2815  MemoryContext stmt_mcontext = NULL;
2816  char *curname = NULL;
2817  PLpgSQL_expr *query;
2818  ParamListInfo paramLI;
2819  Portal portal;
2820  int rc;
2821 
2822  /* ----------
2823  * Get the cursor variable and if it has an assigned name, check
2824  * that it's not in use currently.
2825  * ----------
2826  */
2827  curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]);
2828  if (!curvar->isnull)
2829  {
2830  MemoryContext oldcontext;
2831 
2832  /* We only need stmt_mcontext to hold the cursor name string */
2833  stmt_mcontext = get_stmt_mcontext(estate);
2834  oldcontext = MemoryContextSwitchTo(stmt_mcontext);
2835  curname = TextDatumGetCString(curvar->value);
2836  MemoryContextSwitchTo(oldcontext);
2837 
2838  if (SPI_cursor_find(curname) != NULL)
2839  ereport(ERROR,
2840  (errcode(ERRCODE_DUPLICATE_CURSOR),
2841  errmsg("cursor \"%s\" already in use", curname)));
2842  }
2843 
2844  /* ----------
2845  * Open the cursor just like an OPEN command
2846  *
2847  * Note: parser should already have checked that statement supplies
2848  * args iff cursor needs them, but we check again to be safe.
2849  * ----------
2850  */
2851  if (stmt->argquery != NULL)
2852  {
2853  /* ----------
2854  * OPEN CURSOR with args. We fake a SELECT ... INTO ...
2855  * statement to evaluate the args and put 'em into the
2856  * internal row.
2857  * ----------
2858  */
2859  PLpgSQL_stmt_execsql set_args;
2860 
2861  if (curvar->cursor_explicit_argrow < 0)
2862  ereport(ERROR,
2863  (errcode(ERRCODE_SYNTAX_ERROR),
2864  errmsg("arguments given for cursor without arguments")));
2865 
2866  memset(&set_args, 0, sizeof(set_args));
2867  set_args.cmd_type = PLPGSQL_STMT_EXECSQL;
2868  set_args.lineno = stmt->lineno;
2869  set_args.sqlstmt = stmt->argquery;
2870  set_args.into = true;
2871  /* XXX historically this has not been STRICT */
2872  set_args.target = (PLpgSQL_variable *)
2873  (estate->datums[curvar->cursor_explicit_argrow]);
2874 
2875  if (exec_stmt_execsql(estate, &set_args) != PLPGSQL_RC_OK)
2876  elog(ERROR, "open cursor failed during argument processing");
2877  }
2878  else
2879  {
2880  if (curvar->cursor_explicit_argrow >= 0)
2881  ereport(ERROR,
2882  (errcode(ERRCODE_SYNTAX_ERROR),
2883  errmsg("arguments required for cursor")));
2884  }
2885 
2886  query = curvar->cursor_explicit_expr;
2887  Assert(query);
2888 
2889  if (query->plan == NULL)
2890  exec_prepare_plan(estate, query, curvar->cursor_options);
2891 
2892  /*
2893  * Set up ParamListInfo for this query
2894  */
2895  paramLI = setup_param_list(estate, query);
2896 
2897  /*
2898  * Open the cursor (the paramlist will get copied into the portal)
2899  */
2900  portal = SPI_cursor_open_with_paramlist(curname, query->plan,
2901  paramLI,
2902  estate->readonly_func);
2903  if (portal == NULL)
2904  elog(ERROR, "could not open cursor: %s",
2905  SPI_result_code_string(SPI_result));
2906 
2907  /*
2908  * If cursor variable was NULL, store the generated portal name in it
2909  */
2910  if (curname == NULL)
2911  assign_text_var(estate, curvar, portal->name);
2912 
2913  /*
2914  * Clean up before entering exec_for_query
2915  */
2916  exec_eval_cleanup(estate);
2917  if (stmt_mcontext)
2918  MemoryContextReset(stmt_mcontext);
2919 
2920  /*
2921  * Execute the loop. We can't prefetch because the cursor is accessible
2922  * to the user, for instance via UPDATE WHERE CURRENT OF within the loop.
2923  */
2924  rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, false);
2925 
2926  /* ----------
2927  * Close portal, and restore cursor variable if it was initially NULL.
2928  * ----------
2929  */
2930  SPI_cursor_close(portal);
2931 
2932  if (curname == NULL)
2933  assign_simple_var(estate, curvar, (Datum) 0, true, false);
2934 
2935  return rc;
2936 }
2937 
2938 
2939 /* ----------
2940  * exec_stmt_foreach_a Loop over elements or slices of an array
2941  *
2942  * When looping over elements, the loop variable is the same type that the
2943  * array stores (eg: integer), when looping through slices, the loop variable
2944  * is an array of size and dimensions to match the size of the slice.
2945  * ----------
2946  */
2947 static int
2948 exec_stmt_foreach_a(PLpgSQL_execstate *estate, PLpgSQL_stmt_foreach_a *stmt)
2949 {
2950  ArrayType *arr;
2951  Oid arrtype;
2952  int32 arrtypmod;
2953  PLpgSQL_datum *loop_var;
2954  Oid loop_var_elem_type;
2955  bool found = false;
2956  int rc = PLPGSQL_RC_OK;
2957  MemoryContext stmt_mcontext;
2958  MemoryContext oldcontext;
2959  ArrayIterator array_iterator;
2960  Oid iterator_result_type;
2961  int32 iterator_result_typmod;
2962  Datum value;
2963  bool isnull;
2964 
2965  /* get the value of the array expression */
2966  value = exec_eval_expr(estate, stmt->expr, &isnull, &arrtype, &arrtypmod);
2967  if (isnull)
2968  ereport(ERROR,
2969  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
2970  errmsg("FOREACH expression must not be null")));
2971 
2972  /*
2973  * Do as much as possible of the code below in stmt_mcontext, to avoid any
2974  * leaks from called subroutines. We need a private stmt_mcontext since
2975  * we'll be calling arbitrary statement code.
2976  */
2977  stmt_mcontext = get_stmt_mcontext(estate);
2978  push_stmt_mcontext(estate);
2979  oldcontext = MemoryContextSwitchTo(stmt_mcontext);
2980 
2981  /* check the type of the expression - must be an array */
2982  if (!OidIsValid(get_element_type(arrtype)))
2983  ereport(ERROR,
2984  (errcode(ERRCODE_DATATYPE_MISMATCH),
2985  errmsg("FOREACH expression must yield an array, not type %s",
2986  format_type_be(arrtype))));
2987 
2988  /*
2989  * We must copy the array into stmt_mcontext, else it will disappear in
2990  * exec_eval_cleanup. This is annoying, but cleanup will certainly happen
2991  * while running the loop body, so we have little choice.
2992  */
2993  arr = DatumGetArrayTypePCopy(value);
2994 
2995  /* Clean up any leftover temporary memory */
2996  exec_eval_cleanup(estate);
2997 
2998  /* Slice dimension must be less than or equal to array dimension */
2999  if (stmt->slice < 0 || stmt->slice > ARR_NDIM(arr))
3000  ereport(ERROR,
3001  (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
3002  errmsg("slice dimension (%d) is out of the valid range 0..%d",
3003  stmt->slice, ARR_NDIM(arr))));
3004 
3005  /* Set up the loop variable and see if it is of an array type */
3006  loop_var = estate->datums[stmt->varno];
3007  if (loop_var->dtype == PLPGSQL_DTYPE_REC ||
3008  loop_var->dtype == PLPGSQL_DTYPE_ROW)
3009  {
3010  /*
3011  * Record/row variable is certainly not of array type, and might not
3012  * be initialized at all yet, so don't try to get its type
3013  */
3014  loop_var_elem_type = InvalidOid;
3015  }
3016  else
3017  loop_var_elem_type = get_element_type(plpgsql_exec_get_datum_type(estate,
3018  loop_var));
3019 
3020  /*
3021  * Sanity-check the loop variable type. We don't try very hard here, and
3022  * should not be too picky since it's possible that exec_assign_value can
3023  * coerce values of different types. But it seems worthwhile to complain
3024  * if the array-ness of the loop variable is not right.
3025  */
3026  if (stmt->slice > 0 && loop_var_elem_type == InvalidOid)
3027  ereport(ERROR,
3028  (errcode(ERRCODE_DATATYPE_MISMATCH),
3029  errmsg("FOREACH ... SLICE loop variable must be of an array type")));
3030  if (stmt->slice == 0 && loop_var_elem_type != InvalidOid)
3031  ereport(ERROR,
3032  (errcode(ERRCODE_DATATYPE_MISMATCH),
3033  errmsg("FOREACH loop variable must not be of an array type")));
3034 
3035  /* Create an iterator to step through the array */
3036  array_iterator = array_create_iterator(arr, stmt->slice, NULL);
3037 
3038  /* Identify iterator result type */
3039  if (stmt->slice > 0)
3040  {
3041  /* When slicing, nominal type of result is same as array type */
3042  iterator_result_type = arrtype;
3043  iterator_result_typmod = arrtypmod;
3044  }
3045  else
3046  {
3047  /* Without slicing, results are individual array elements */
3048  iterator_result_type = ARR_ELEMTYPE(arr);
3049  iterator_result_typmod = arrtypmod;
3050  }
3051 
3052  /* Iterate over the array elements or slices */
3053  while (array_iterate(array_iterator, &value, &isnull))
3054  {
3055  found = true; /* looped at least once */
3056 
3057  /* exec_assign_value and exec_stmts must run in the main context */
3058  MemoryContextSwitchTo(oldcontext);
3059 
3060  /* Assign current element/slice to the loop variable */
3061  exec_assign_value(estate, loop_var, value, isnull,
3062  iterator_result_type, iterator_result_typmod);
3063 
3064  /* In slice case, value is temporary; must free it to avoid leakage */
3065  if (stmt->slice > 0)
3066  pfree(DatumGetPointer(value));
3067 
3068  /*
3069  * Execute the statements
3070  */
3071  rc = exec_stmts(estate, stmt->body);
3072 
3073  LOOP_RC_PROCESSING(stmt->label, break);
3074 
3075  MemoryContextSwitchTo(stmt_mcontext);
3076  }
3077 
3078  /* Restore memory context state */
3079  MemoryContextSwitchTo(oldcontext);
3080  pop_stmt_mcontext(estate);
3081 
3082  /* Release temporary memory, including the array value */
3083  MemoryContextReset(stmt_mcontext);
3084 
3085  /*
3086  * Set the FOUND variable to indicate the result of executing the loop
3087  * (namely, whether we looped one or more times). This must be set here so
3088  * that it does not interfere with the value of the FOUND variable inside
3089  * the loop processing itself.
3090  */
3091  exec_set_found(estate, found);
3092 
3093  return rc;
3094 }
3095 
3096 
3097 /* ----------
3098  * exec_stmt_exit Implements EXIT and CONTINUE
3099  *
3100  * This begins the process of exiting / restarting a loop.
3101  * ----------
3102  */
3103 static int
3104 exec_stmt_exit(PLpgSQL_execstate *estate, PLpgSQL_stmt_exit *stmt)
3105 {
3106  /*
3107  * If the exit / continue has a condition, evaluate it
3108  */
3109  if (stmt->cond != NULL)
3110  {
3111  bool value;
3112  bool isnull;
3113 
3114  value = exec_eval_boolean(estate, stmt->cond, &isnull);
3115  exec_eval_cleanup(estate);
3116  if (isnull || value == false)
3117  return PLPGSQL_RC_OK;
3118  }
3119 
3120  estate->exitlabel = stmt->label;
3121  if (stmt->is_exit)
3122  return PLPGSQL_RC_EXIT;
3123  else
3124  return PLPGSQL_RC_CONTINUE;
3125 }
3126 
3127 
3128 /* ----------
3129  * exec_stmt_return Evaluate an expression and start
3130  * returning from the function.
3131  *
3132  * Note: The result may be in the eval_mcontext. Therefore, we must not
3133  * do exec_eval_cleanup while unwinding the control stack.
3134  * ----------
3135  */
3136 static int
3137 exec_stmt_return(PLpgSQL_execstate *estate, PLpgSQL_stmt_return *stmt)
3138 {
3139  /*
3140  * If processing a set-returning PL/pgSQL function, the final RETURN
3141  * indicates that the function is finished producing tuples. The rest of
3142  * the work will be done at the top level.
3143  */
3144  if (estate->retisset)
3145  return PLPGSQL_RC_RETURN;
3146 
3147  /* initialize for null result */
3148  estate->retval = (Datum) 0;
3149  estate->retisnull = true;
3150  estate->rettype = InvalidOid;
3151 
3152  /*
3153  * Special case path when the RETURN expression is a simple variable
3154  * reference; in particular, this path is always taken in functions with
3155  * one or more OUT parameters.
3156  *
3157  * This special case is especially efficient for returning variables that
3158  * have R/W expanded values: we can put the R/W pointer directly into
3159  * estate->retval, leading to transferring the value to the caller's
3160  * context cheaply. If we went through exec_eval_expr we'd end up with a
3161  * R/O pointer. It's okay to skip MakeExpandedObjectReadOnly here since
3162  * we know we won't need the variable's value within the function anymore.
3163  */
3164  if (stmt->retvarno >= 0)
3165  {
3166  PLpgSQL_datum *retvar = estate->datums[stmt->retvarno];
3167 
3168  switch (retvar->dtype)
3169  {
3170  case PLPGSQL_DTYPE_PROMISE:
3171  /* fulfill promise if needed, then handle like regular var */
3172  plpgsql_fulfill_promise(estate, (PLpgSQL_var *) retvar);
3173 
3174  /* FALL THRU */
3175 
3176  case PLPGSQL_DTYPE_VAR:
3177  {
3178  PLpgSQL_var *var = (PLpgSQL_var *) retvar;
3179 
3180  estate->retval = var->value;
3181  estate->retisnull = var->isnull;
3182  estate->rettype = var->datatype->typoid;
3183 
3184  /*
3185  * A PLpgSQL_var could not be of composite type, so
3186  * conversion must fail if retistuple. We throw a custom
3187  * error mainly for consistency with historical behavior.
3188  * For the same reason, we don't throw error if the result
3189  * is NULL. (Note that plpgsql_exec_trigger assumes that
3190  * any non-null result has been verified to be composite.)
3191  */
3192  if (estate->retistuple && !estate->retisnull)
3193  ereport(ERROR,
3194  (errcode(ERRCODE_DATATYPE_MISMATCH),
3195  errmsg("cannot return non-composite value from function returning composite type")));
3196  }
3197  break;
3198 
3199  case PLPGSQL_DTYPE_REC:
3200  {
3201  PLpgSQL_rec *rec = (PLpgSQL_rec *) retvar;
3202 
3203  /* If record is empty, we return NULL not a row of nulls */
3204  if (rec->erh && !ExpandedRecordIsEmpty(rec->erh))
3205  {
3206  estate->retval = ExpandedRecordGetDatum(rec->erh);
3207  estate->retisnull = false;
3208  estate->rettype = rec->rectypeid;
3209  }
3210  }
3211  break;
3212 
3213  case PLPGSQL_DTYPE_ROW:
3214  {
3215  PLpgSQL_row *row = (PLpgSQL_row *) retvar;
3216  int32 rettypmod;
3217 
3218  /* We get here if there are multiple OUT parameters */
3219  exec_eval_datum(estate,
3220  (PLpgSQL_datum *) row,
3221  &estate->rettype,
3222  &rettypmod,
3223  &estate->retval,
3224  &estate->retisnull);
3225  }
3226  break;
3227 
3228  default:
3229  elog(ERROR, "unrecognized dtype: %d", retvar->dtype);
3230  }
3231 
3232  return PLPGSQL_RC_RETURN;
3233  }
3234 
3235  if (stmt->expr != NULL)
3236  {
3237  int32 rettypmod;
3238 
3239  estate->retval = exec_eval_expr(estate, stmt->expr,
3240  &(estate->retisnull),
3241  &(estate->rettype),
3242  &rettypmod);
3243 
3244  /*
3245  * As in the DTYPE_VAR case above, throw a custom error if a non-null,
3246  * non-composite value is returned in a function returning tuple.
3247  */
3248  if (estate->retistuple && !estate->retisnull &&
3249  !type_is_rowtype(estate->rettype))
3250  ereport(ERROR,
3251  (errcode(ERRCODE_DATATYPE_MISMATCH),
3252  errmsg("cannot return non-composite value from function returning composite type")));
3253 
3254  return PLPGSQL_RC_RETURN;
3255  }
3256 
3257  /*
3258  * Special hack for function returning VOID: instead of NULL, return a
3259  * non-null VOID value. This is of dubious importance but is kept for
3260  * backwards compatibility. We don't do it for procedures, though.
3261  */
3262  if (estate->fn_rettype == VOIDOID &&
3263  estate->func->fn_prokind != PROKIND_PROCEDURE)
3264  {
3265  estate->retval = (Datum) 0;
3266  estate->retisnull = false;
3267  estate->rettype = VOIDOID;
3268  }
3269 
3270  return PLPGSQL_RC_RETURN;
3271 }
3272 
3273 /* ----------
3274  * exec_stmt_return_next Evaluate an expression and add it to the
3275  * list of tuples returned by the current
3276  * SRF.
3277  * ----------
3278  */
3279 static int
3280 exec_stmt_return_next(PLpgSQL_execstate *estate,
3281  PLpgSQL_stmt_return_next *stmt)
3282 {
3283  TupleDesc tupdesc;
3284  int natts;
3285  HeapTuple tuple;
3286  MemoryContext oldcontext;
3287 
3288  if (!estate->retisset)
3289  ereport(ERROR,
3290  (errcode(ERRCODE_SYNTAX_ERROR),
3291  errmsg("cannot use RETURN NEXT in a non-SETOF function")));
3292 
3293  if (estate->tuple_store == NULL)
3294  exec_init_tuple_store(estate);
3295 
3296  /* tuple_store_desc will be filled by exec_init_tuple_store */
3297  tupdesc = estate->tuple_store_desc;
3298  natts = tupdesc->natts;
3299 
3300  /*
3301  * Special case path when the RETURN NEXT expression is a simple variable
3302  * reference; in particular, this path is always taken in functions with
3303  * one or more OUT parameters.
3304  *
3305  * Unlike exec_stmt_return, there's no special win here for R/W expanded
3306  * values, since they'll have to get flattened to go into the tuplestore.
3307  * Indeed, we'd better make them R/O to avoid any risk of the casting step
3308  * changing them in-place.
3309  */
3310  if (stmt->retvarno >= 0)
3311  {
3312  PLpgSQL_datum *retvar = estate->datums[stmt->retvarno];
3313 
3314  switch (retvar->dtype)
3315  {
3316  case PLPGSQL_DTYPE_PROMISE:
3317  /* fulfill promise if needed, then handle like regular var */
3318  plpgsql_fulfill_promise(estate, (PLpgSQL_var *) retvar);
3319 
3320  /* FALL THRU */
3321 
3322  case PLPGSQL_DTYPE_VAR:
3323  {
3324  PLpgSQL_var *var = (PLpgSQL_var *) retvar;
3325  Datum retval = var->value;
3326  bool isNull = var->isnull;
3327  Form_pg_attribute attr = TupleDescAttr(tupdesc, 0);
3328 
3329  if (natts != 1)
3330  ereport(ERROR,
3331  (errcode(ERRCODE_DATATYPE_MISMATCH),
3332  errmsg("wrong result type supplied in RETURN NEXT")));
3333 
3334  /* let's be very paranoid about the cast step */
3335  retval = MakeExpandedObjectReadOnly(retval,
3336  isNull,
3337  var->datatype->typlen);
3338 
3339  /* coerce type if needed */
3340  retval = exec_cast_value(estate,
3341  retval,
3342  &isNull,
3343  var->datatype->typoid,
3344  var->datatype->atttypmod,
3345  attr->atttypid,
3346  attr->atttypmod);
3347 
3348  tuplestore_putvalues(estate->tuple_store, tupdesc,
3349  &retval, &isNull);
3350  }
3351  break;
3352 
3353  case PLPGSQL_DTYPE_REC:
3354  {
3355  PLpgSQL_rec *rec = (PLpgSQL_rec *) retvar;
3356  TupleDesc rec_tupdesc;
3357  TupleConversionMap *tupmap;
3358 
3359  /* If rec is null, try to convert it to a row of nulls */
3360  if (rec->erh == NULL)
3361  instantiate_empty_record_variable(estate, rec);
3362  if (ExpandedRecordIsEmpty(rec->erh))
3363  deconstruct_expanded_record(rec->erh);
3364 
3365  /* Use eval_mcontext for tuple conversion work */
3366  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
3367  rec_tupdesc = expanded_record_get_tupdesc(rec->erh);
3368  tupmap = convert_tuples_by_position(rec_tupdesc,
3369  tupdesc,
3370  gettext_noop("wrong record type supplied in RETURN NEXT"));
3371  tuple = expanded_record_get_tuple(rec->erh);
3372  if (tupmap)
3373  tuple = execute_attr_map_tuple(tuple, tupmap);
3374  tuplestore_puttuple(estate->tuple_store, tuple);
3375  MemoryContextSwitchTo(oldcontext);
3376  }
3377  break;
3378 
3379  case PLPGSQL_DTYPE_ROW:
3380  {
3381  PLpgSQL_row *row = (PLpgSQL_row *) retvar;
3382 
3383  /* We get here if there are multiple OUT parameters */
3384 
3385  /* Use eval_mcontext for tuple conversion work */
3386  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
3387  tuple = make_tuple_from_row(estate, row, tupdesc);
3388  if (tuple == NULL) /* should not happen */
3389  ereport(ERROR,
3390  (errcode(ERRCODE_DATATYPE_MISMATCH),
3391  errmsg("wrong record type supplied in RETURN NEXT")));
3392  tuplestore_puttuple(estate->tuple_store, tuple);
3393  MemoryContextSwitchTo(oldcontext);
3394  }
3395  break;
3396 
3397  default:
3398  elog(ERROR, "unrecognized dtype: %d", retvar->dtype);
3399  break;
3400  }
3401  }
3402  else if (stmt->expr)
3403  {
3404  Datum retval;
3405  bool isNull;
3406  Oid rettype;
3407  int32 rettypmod;
3408 
3409  retval = exec_eval_expr(estate,
3410  stmt->expr,
3411  &isNull,
3412  &rettype,
3413  &rettypmod);
3414 
3415  if (estate->retistuple)
3416  {
3417  /* Expression should be of RECORD or composite type */
3418  if (!isNull)
3419  {
3420  HeapTupleData tmptup;
3421  TupleDesc retvaldesc;
3422  TupleConversionMap *tupmap;
3423 
3424  if (!type_is_rowtype(rettype))
3425  ereport(ERROR,
3426  (errcode(ERRCODE_DATATYPE_MISMATCH),
3427  errmsg("cannot return non-composite value from function returning composite type")));
3428 
3429  /* Use eval_mcontext for tuple conversion work */
3430  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
3431  retvaldesc = deconstruct_composite_datum(retval, &tmptup);
3432  tuple = &tmptup;
3433  tupmap = convert_tuples_by_position(retvaldesc, tupdesc,
3434  gettext_noop("returned record type does not match expected record type"));
3435  if (tupmap)
3436  tuple = execute_attr_map_tuple(tuple, tupmap);
3437  tuplestore_puttuple(estate->tuple_store, tuple);
3438  ReleaseTupleDesc(retvaldesc);
3439  MemoryContextSwitchTo(oldcontext);
3440  }
3441  else
3442  {
3443  /* Composite NULL --- store a row of nulls */
3444  Datum *nulldatums;
3445  bool *nullflags;
3446 
3447  nulldatums = (Datum *)
3448  eval_mcontext_alloc0(estate, natts * sizeof(Datum));
3449  nullflags = (bool *)
3450  eval_mcontext_alloc(estate, natts * sizeof(bool));
3451  memset(nullflags, true, natts * sizeof(bool));
3452  tuplestore_putvalues(estate->tuple_store, tupdesc,
3453  nulldatums, nullflags);
3454  }
3455  }
3456  else
3457  {
3458  Form_pg_attribute attr = TupleDescAttr(tupdesc, 0);
3459 
3460  /* Simple scalar result */
3461  if (natts != 1)
3462  ereport(ERROR,
3463  (errcode(ERRCODE_DATATYPE_MISMATCH),
3464  errmsg("wrong result type supplied in RETURN NEXT")));
3465 
3466  /* coerce type if needed */
3467  retval = exec_cast_value(estate,
3468  retval,
3469  &isNull,
3470  rettype,
3471  rettypmod,
3472  attr->atttypid,
3473  attr->atttypmod);
3474 
3475  tuplestore_putvalues(estate->tuple_store, tupdesc,
3476  &retval, &isNull);
3477  }
3478  }
3479  else
3480  {
3481  ereport(ERROR,
3482  (errcode(ERRCODE_SYNTAX_ERROR),
3483  errmsg("RETURN NEXT must have a parameter")));
3484  }
3485 
3486  exec_eval_cleanup(estate);
3487 
3488  return PLPGSQL_RC_OK;
3489 }
3490 
3491 /* ----------
3492  * exec_stmt_return_query Evaluate a query and add it to the
3493  * list of tuples returned by the current
3494  * SRF.
3495  * ----------
3496  */
3497 static int
3498 exec_stmt_return_query(PLpgSQL_execstate *estate,
3499  PLpgSQL_stmt_return_query *stmt)
3500 {
3501  int64 tcount;
3502  DestReceiver *treceiver;
3503  int rc;
3504  uint64 processed;
3505  MemoryContext stmt_mcontext = get_stmt_mcontext(estate);
3506  MemoryContext oldcontext;
3507 
3508  if (!estate->retisset)
3509  ereport(ERROR,
3510  (errcode(ERRCODE_SYNTAX_ERROR),
3511  errmsg("cannot use RETURN QUERY in a non-SETOF function")));
3512 
3513  if (estate->tuple_store == NULL)
3514  exec_init_tuple_store(estate);
3515  /* There might be some tuples in the tuplestore already */
3516  tcount = tuplestore_tuple_count(estate->tuple_store);
3517 
3518  /*
3519  * Set up DestReceiver to transfer results directly to tuplestore,
3520  * converting rowtype if necessary. DestReceiver lives in mcontext.
3521  */
3522  oldcontext = MemoryContextSwitchTo(stmt_mcontext);
3523  treceiver = CreateDestReceiver(DestTuplestore);
3524  SetTuplestoreDestReceiverParams(treceiver,
3525  estate->tuple_store,
3526  estate->tuple_store_cxt,
3527  false,
3528  estate->tuple_store_desc,
3529  gettext_noop("structure of query does not match function result type"));
3530  MemoryContextSwitchTo(oldcontext);
3531 
3532  if (stmt->query != NULL)
3533  {
3534  /* static query */
3535  PLpgSQL_expr *expr = stmt->query;
3536  ParamListInfo paramLI;
3537  SPIExecuteOptions options;
3538 
3539  /*
3540  * On the first call for this expression generate the plan.
3541  */
3542  if (expr->plan == NULL)
3543  exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK);
3544 
3545  /*
3546  * Set up ParamListInfo to pass to executor
3547  */
3548  paramLI = setup_param_list(estate, expr);
3549 
3550  /*
3551  * Execute the query
3552  */
3553  memset(&options, 0, sizeof(options));
3554  options.params = paramLI;
3555  options.read_only = estate->readonly_func;
3556  options.must_return_tuples = true;
3557  options.dest = treceiver;
3558 
3559  rc = SPI_execute_plan_extended(expr->plan, &options);
3560  if (rc < 0)
3561  elog(ERROR, "SPI_execute_plan_extended failed executing query \"%s\": %s",
3562  expr->query, SPI_result_code_string(rc));
3563  }
3564  else
3565  {
3566  /* RETURN QUERY EXECUTE */
3567  Datum query;
3568  bool isnull;
3569  Oid restype;
3570  int32 restypmod;
3571  char *querystr;
3572  SPIExecuteOptions options;
3573 
3574  /*
3575  * Evaluate the string expression after the EXECUTE keyword. Its
3576  * result is the querystring we have to execute.
3577  */
3578  Assert(stmt->dynquery != NULL);
3579  query = exec_eval_expr(estate, stmt->dynquery,
3580  &isnull, &restype, &restypmod);
3581  if (isnull)
3582  ereport(ERROR,
3583  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
3584  errmsg("query string argument of EXECUTE is null")));
3585 
3586  /* Get the C-String representation */
3587  querystr = convert_value_to_string(estate, query, restype);
3588 
3589  /* copy it into the stmt_mcontext before we clean up */
3590  querystr = MemoryContextStrdup(stmt_mcontext, querystr);
3591 
3592  exec_eval_cleanup(estate);
3593 
3594  /* Execute query, passing params if necessary */
3595  memset(&options, 0, sizeof(options));
3596  options.params = exec_eval_using_params(estate,
3597  stmt->params);
3598  options.read_only = estate->readonly_func;
3599  options.must_return_tuples = true;
3600  options.dest = treceiver;
3601 
3602  rc = SPI_execute_extended(querystr, &options);
3603  if (rc < 0)
3604  elog(ERROR, "SPI_execute_extended failed executing query \"%s\": %s",
3605  querystr, SPI_result_code_string(rc));
3606  }
3607 
3608  /* Clean up */
3609  treceiver->rDestroy(treceiver);
3610  exec_eval_cleanup(estate);
3611  MemoryContextReset(stmt_mcontext);
3612 
3613  /* Count how many tuples we got */
3614  processed = tuplestore_tuple_count(estate->tuple_store) - tcount;
3615 
3616  estate->eval_processed = processed;
3617  exec_set_found(estate, processed != 0);
3618 
3619  return PLPGSQL_RC_OK;
3620 }
3621 
3622 static void
3623 exec_init_tuple_store(PLpgSQL_execstate *estate)
3624 {
3625  ReturnSetInfo *rsi = estate->rsi;
3626  MemoryContext oldcxt;
3627  ResourceOwner oldowner;
3628 
3629  /*
3630  * Check caller can handle a set result in the way we want
3631  */
3632  if (!rsi || !IsA(rsi, ReturnSetInfo) ||
3633  (rsi->allowedModes & SFRM_Materialize) == 0 ||
3634  rsi->expectedDesc == NULL)
3635  ereport(ERROR,
3636  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3637  errmsg("set-valued function called in context that cannot accept a set")));
3638 
3639  /*
3640  * Switch to the right memory context and resource owner for storing the
3641  * tuplestore for return set. If we're within a subtransaction opened for
3642  * an exception-block, for example, we must still create the tuplestore in
3643  * the resource owner that was active when this function was entered, and
3644  * not in the subtransaction resource owner.
3645  */
3646  oldcxt = MemoryContextSwitchTo(estate->tuple_store_cxt);
3647  oldowner = CurrentResourceOwner;
3648  CurrentResourceOwner = estate->tuple_store_owner;
3649 
3650  estate->tuple_store =
3651  tuplestore_begin_heap(rsi->allowedModes & SFRM_Materialize_Random,
3652  false, work_mem);
3653 
3654  CurrentResourceOwner = oldowner;
3655  MemoryContextSwitchTo(oldcxt);
3656 
3657  estate->tuple_store_desc = rsi->expectedDesc;
3658 }
3659 
3660 #define SET_RAISE_OPTION_TEXT(opt, name) \
3661 do { \
3662  if (opt) \
3663  ereport(ERROR, \
3664  (errcode(ERRCODE_SYNTAX_ERROR), \
3665  errmsg("RAISE option already specified: %s", \
3666  name))); \
3667  opt = MemoryContextStrdup(stmt_mcontext, extval); \
3668 } while (0)
3669 
3670 /* ----------
3671  * exec_stmt_raise Build a message and throw it with elog()
3672  * ----------
3673  */
3674 static int
3675 exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt)
3676 {
3677  int err_code = 0;
3678  char *condname = NULL;
3679  char *err_message = NULL;
3680  char *err_detail = NULL;
3681  char *err_hint = NULL;
3682  char *err_column = NULL;
3683  char *err_constraint = NULL;
3684  char *err_datatype = NULL;
3685  char *err_table = NULL;
3686  char *err_schema = NULL;
3687  MemoryContext stmt_mcontext;
3688  ListCell *lc;
3689 
3690  /* RAISE with no parameters: re-throw current exception */
3691  if (stmt->condname == NULL && stmt->message == NULL &&
3692  stmt->options == NIL)
3693  {
3694  if (estate->cur_error != NULL)
3695  ReThrowError(estate->cur_error);
3696  /* oops, we're not inside a handler */
3697  ereport(ERROR,
3698  (errcode(ERRCODE_STACKED_DIAGNOSTICS_ACCESSED_WITHOUT_ACTIVE_HANDLER),
3699  errmsg("RAISE without parameters cannot be used outside an exception handler")));
3700  }
3701 
3702  /* We'll need to accumulate the various strings in stmt_mcontext */
3703  stmt_mcontext = get_stmt_mcontext(estate);
3704 
3705  if (stmt->condname)
3706  {
3707  err_code = plpgsql_recognize_err_condition(stmt->condname, true);
3708  condname = MemoryContextStrdup(stmt_mcontext, stmt->condname);
3709  }
3710 
3711  if (stmt->message)
3712  {
3713  StringInfoData ds;
3714  ListCell *current_param;
3715  char *cp;
3716  MemoryContext oldcontext;
3717 
3718  /* build string in stmt_mcontext */
3719  oldcontext = MemoryContextSwitchTo(stmt_mcontext);
3720  initStringInfo(&ds);
3721  MemoryContextSwitchTo(oldcontext);
3722 
3723  current_param = list_head(stmt->params);
3724 
3725  for (cp = stmt->message; *cp; cp++)
3726  {
3727  /*
3728  * Occurrences of a single % are replaced by the next parameter's
3729  * external representation. Double %'s are converted to one %.
3730  */
3731  if (cp[0] == '%')
3732  {
3733  Oid paramtypeid;
3734  int32 paramtypmod;
3735  Datum paramvalue;
3736  bool paramisnull;
3737  char *extval;
3738 
3739  if (cp[1] == '%')
3740  {
3741  appendStringInfoChar(&ds, '%');
3742  cp++;
3743  continue;
3744  }
3745 
3746  /* should have been checked at compile time */
3747  if (current_param == NULL)
3748  elog(ERROR, "unexpected RAISE parameter list length");
3749 
3750  paramvalue = exec_eval_expr(estate,
3751  (PLpgSQL_expr *) lfirst(current_param),
3752  &paramisnull,
3753  &paramtypeid,
3754  &paramtypmod);
3755 
3756  if (paramisnull)
3757  extval = "<NULL>";
3758  else
3759  extval = convert_value_to_string(estate,
3760  paramvalue,
3761  paramtypeid);
3762  appendStringInfoString(&ds, extval);
3763  current_param = lnext(stmt->params, current_param);
3764  exec_eval_cleanup(estate);
3765  }
3766  else
3767  appendStringInfoChar(&ds, cp[0]);
3768  }
3769 
3770  /* should have been checked at compile time */
3771  if (current_param != NULL)
3772  elog(ERROR, "unexpected RAISE parameter list length");
3773 
3774  err_message = ds.data;
3775  }
3776 
3777  foreach(lc, stmt->options)
3778  {
3779  PLpgSQL_raise_option *opt = (PLpgSQL_raise_option *) lfirst(lc);
3780  Datum optionvalue;
3781  bool optionisnull;
3782  Oid optiontypeid;
3783  int32 optiontypmod;
3784  char *extval;
3785 
3786  optionvalue = exec_eval_expr(estate, opt->expr,
3787  &optionisnull,
3788  &optiontypeid,
3789  &optiontypmod);
3790  if (optionisnull)
3791  ereport(ERROR,
3792  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
3793  errmsg("RAISE statement option cannot be null")));
3794 
3795  extval = convert_value_to_string(estate, optionvalue, optiontypeid);
3796 
3797  switch (opt->opt_type)
3798  {
3799  case PLPGSQL_RAISEOPTION_ERRCODE:
3800  if (err_code)
3801  ereport(ERROR,
3802  (errcode(ERRCODE_SYNTAX_ERROR),
3803  errmsg("RAISE option already specified: %s",
3804  "ERRCODE")));
3805  err_code = plpgsql_recognize_err_condition(extval, true);
3806  condname = MemoryContextStrdup(stmt_mcontext, extval);
3807  break;
3808  case PLPGSQL_RAISEOPTION_MESSAGE:
3809  SET_RAISE_OPTION_TEXT(err_message, "MESSAGE");
3810  break;
3811  case PLPGSQL_RAISEOPTION_DETAIL:
3812  SET_RAISE_OPTION_TEXT(err_detail, "DETAIL");
3813  break;
3814  case PLPGSQL_RAISEOPTION_HINT:
3815  SET_RAISE_OPTION_TEXT(err_hint, "HINT");
3816  break;
3817  case PLPGSQL_RAISEOPTION_COLUMN:
3818  SET_RAISE_OPTION_TEXT(err_column, "COLUMN");
3819  break;
3820  case PLPGSQL_RAISEOPTION_CONSTRAINT:
3821  SET_RAISE_OPTION_TEXT(err_constraint, "CONSTRAINT");
3822  break;
3823  case PLPGSQL_RAISEOPTION_DATATYPE:
3824  SET_RAISE_OPTION_TEXT(err_datatype, "DATATYPE");
3825  break;
3826  case PLPGSQL_RAISEOPTION_TABLE:
3827  SET_RAISE_OPTION_TEXT(err_table, "TABLE");
3828  break;
3829  case PLPGSQL_RAISEOPTION_SCHEMA:
3830  SET_RAISE_OPTION_TEXT(err_schema, "SCHEMA");
3831  break;
3832  default:
3833  elog(ERROR, "unrecognized raise option: %d", opt->opt_type);
3834  }
3835 
3836  exec_eval_cleanup(estate);
3837  }
3838 
3839  /* Default code if nothing specified */
3840  if (err_code == 0 && stmt->elog_level >= ERROR)
3841  err_code = ERRCODE_RAISE_EXCEPTION;
3842 
3843  /* Default error message if nothing specified */
3844  if (err_message == NULL)
3845  {
3846  if (condname)
3847  {
3848  err_message = condname;
3849  condname = NULL;
3850  }
3851  else
3852  err_message = MemoryContextStrdup(stmt_mcontext,
3853  unpack_sql_state(err_code));
3854  }
3855 
3856  /*
3857  * Throw the error (may or may not come back)
3858  */
3859  ereport(stmt->elog_level,
3860  (err_code ? errcode(err_code) : 0,
3861  errmsg_internal("%s", err_message),
3862  (err_detail != NULL) ? errdetail_internal("%s", err_detail) : 0,
3863  (err_hint != NULL) ? errhint("%s", err_hint) : 0,
3864  (err_column != NULL) ?
3865  err_generic_string(PG_DIAG_COLUMN_NAME, err_column) : 0,
3866  (err_constraint != NULL) ?
3867  err_generic_string(PG_DIAG_CONSTRAINT_NAME, err_constraint) : 0,
3868  (err_datatype != NULL) ?
3869  err_generic_string(PG_DIAG_DATATYPE_NAME, err_datatype) : 0,
3870  (err_table != NULL) ?
3871  err_generic_string(PG_DIAG_TABLE_NAME, err_table) : 0,
3872  (err_schema != NULL) ?
3873  err_generic_string(PG_DIAG_SCHEMA_NAME, err_schema) : 0));
3874 
3875  /* Clean up transient strings */
3876  MemoryContextReset(stmt_mcontext);
3877 
3878  return PLPGSQL_RC_OK;
3879 }
3880 
3881 /* ----------
3882  * exec_stmt_assert Assert statement
3883  * ----------
3884  */
3885 static int
3886 exec_stmt_assert(PLpgSQL_execstate *estate, PLpgSQL_stmt_assert *stmt)
3887 {
3888  bool value;
3889  bool isnull;
3890 
3891  /* do nothing when asserts are not enabled */
3892  if (!plpgsql_check_asserts)
3893  return PLPGSQL_RC_OK;
3894 
3895  value = exec_eval_boolean(estate, stmt->cond, &isnull);
3896  exec_eval_cleanup(estate);
3897 
3898  if (isnull || !value)
3899  {
3900  char *message = NULL;
3901 
3902  if (stmt->message != NULL)
3903  {
3904  Datum val;
3905  Oid typeid;
3906  int32 typmod;
3907 
3908  val = exec_eval_expr(estate, stmt->message,
3909  &isnull, &typeid, &typmod);
3910  if (!isnull)
3911  message = convert_value_to_string(estate, val, typeid);
3912  /* we mustn't do exec_eval_cleanup here */
3913  }
3914 
3915  ereport(ERROR,
3916  (errcode(ERRCODE_ASSERT_FAILURE),
3917  message ? errmsg_internal("%s", message) :
3918  errmsg("assertion failed")));
3919  }
3920 
3921  return PLPGSQL_RC_OK;
3922 }
3923 
3924 /* ----------
3925  * Initialize a mostly empty execution state
3926  * ----------
3927  */
3928 static void
3929 plpgsql_estate_setup(PLpgSQL_execstate *estate,
3930  PLpgSQL_function *func,
3931  ReturnSetInfo *rsi,
3932  EState *simple_eval_estate,
3933  ResourceOwner simple_eval_resowner)
3934 {
3935  HASHCTL ctl;
3936 
3937  /* this link will be restored at exit from plpgsql_call_handler */
3938  func->cur_estate = estate;
3939 
3940  estate->func = func;
3941  estate->trigdata = NULL;
3942  estate->evtrigdata = NULL;
3943 
3944  estate->retval = (Datum) 0;
3945  estate->retisnull = true;
3946  estate->rettype = InvalidOid;
3947 
3948  estate->fn_rettype = func->fn_rettype;
3949  estate->retistuple = func->fn_retistuple;
3950  estate->retisset = func->fn_retset;
3951 
3952  estate->readonly_func = func->fn_readonly;
3953  estate->atomic = true;
3954 
3955  estate->exitlabel = NULL;
3956  estate->cur_error = NULL;
3957 
3958  estate->tuple_store = NULL;
3959  estate->tuple_store_desc = NULL;
3960  if (rsi)
3961  {
3962  estate->tuple_store_cxt = rsi->econtext->ecxt_per_query_memory;
3963  estate->tuple_store_owner = CurrentResourceOwner;
3964  }
3965  else
3966  {
3967  estate->tuple_store_cxt = NULL;
3968  estate->tuple_store_owner = NULL;
3969  }
3970  estate->rsi = rsi;
3971 
3972  estate->found_varno = func->found_varno;
3973  estate->ndatums = func->ndatums;
3974  estate->datums = NULL;
3975  /* the datums array will be filled by copy_plpgsql_datums() */
3976  estate->datum_context = CurrentMemoryContext;
3977 
3978  /* initialize our ParamListInfo with appropriate hook functions */
3979  estate->paramLI = makeParamList(0);
3980  estate->paramLI->paramFetch = plpgsql_param_fetch;
3981  estate->paramLI->paramFetchArg = (void *) estate;
3982  estate->paramLI->paramCompile = plpgsql_param_compile;
3983  estate->paramLI->paramCompileArg = NULL; /* not needed */
3984  estate->paramLI->parserSetup = (ParserSetupHook) plpgsql_parser_setup;
3985  estate->paramLI->parserSetupArg = NULL; /* filled during use */
3986  estate->paramLI->numParams = estate->ndatums;
3987 
3988  /* set up for use of appropriate simple-expression EState and cast hash */
3989  if (simple_eval_estate)
3990  {
3991  estate->simple_eval_estate = simple_eval_estate;
3992  /* Private cast hash just lives in function's main context */
3993  ctl.keysize = sizeof(plpgsql_CastHashKey);
3994  ctl.entrysize = sizeof(plpgsql_CastHashEntry);
3995  ctl.hcxt = CurrentMemoryContext;
3996  estate->cast_hash = hash_create("PLpgSQL private cast cache",
3997  16, /* start small and extend */
3998  &ctl,
3999  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
4000  estate->cast_hash_context = CurrentMemoryContext;
4001  }
4002  else
4003  {
4004  estate->simple_eval_estate = shared_simple_eval_estate;
4005  /* Create the session-wide cast-info hash table if we didn't already */
4006  if (shared_cast_hash == NULL)
4007  {
4008  shared_cast_context = AllocSetContextCreate(TopMemoryContext,
4009  "PLpgSQL cast info",
4010  ALLOCSET_DEFAULT_SIZES);
4011  ctl.keysize = sizeof(plpgsql_CastHashKey);
4012  ctl.entrysize = sizeof(plpgsql_CastHashEntry);
4013  ctl.hcxt = shared_cast_context;
4014  shared_cast_hash = hash_create("PLpgSQL cast cache",
4015  16, /* start small and extend */
4016  &ctl,
4017  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
4018  }
4019  estate->cast_hash = shared_cast_hash;
4020  estate->cast_hash_context = shared_cast_context;
4021  }
4022  /* likewise for the simple-expression resource owner */
4023  if (simple_eval_resowner)
4024  estate->simple_eval_resowner = simple_eval_resowner;
4025  else
4026  estate->simple_eval_resowner = shared_simple_eval_resowner;
4027 
4028  /* if there's a procedure resowner, it'll be filled in later */
4029  estate->procedure_resowner = NULL;
4030 
4031  /*
4032  * We start with no stmt_mcontext; one will be created only if needed.
4033  * That context will be a direct child of the function's main execution
4034  * context. Additional stmt_mcontexts might be created as children of it.
4035  */
4036  estate->stmt_mcontext = NULL;
4037  estate->stmt_mcontext_parent = CurrentMemoryContext;
4038 
4039  estate->eval_tuptable = NULL;
4040  estate->eval_processed = 0;
4041  estate->eval_econtext = NULL;
4042 
4043  estate->err_stmt = NULL;
4044  estate->err_text = NULL;
4045 
4046  estate->plugin_info = NULL;
4047 
4048  /*
4049  * Create an EState and ExprContext for evaluation of simple expressions.
4050  */
4051  plpgsql_create_econtext(estate);
4052 
4053  /*
4054  * Let the plugin see this function before we initialize any local
4055  * PL/pgSQL variables - note that we also give the plugin a few function
4056  * pointers so it can call back into PL/pgSQL for doing things like
4057  * variable assignments and stack traces
4058  */
4059  if (*plpgsql_plugin_ptr)
4060  {
4061  (*plpgsql_plugin_ptr)->error_callback = plpgsql_exec_error_callback;
4062  (*plpgsql_plugin_ptr)->assign_expr = exec_assign_expr;
4063 
4064  if ((*plpgsql_plugin_ptr)->func_setup)
4065  ((*plpgsql_plugin_ptr)->func_setup) (estate, func);
4066  }
4067 }
4068 
4069 /* ----------
4070  * Release temporary memory used by expression/subselect evaluation
4071  *
4072  * NB: the result of the evaluation is no longer valid after this is done,
4073  * unless it is a pass-by-value datatype.
4074  * ----------
4075  */
4076 static void
4077 exec_eval_cleanup(PLpgSQL_execstate *estate)
4078 {
4079  /* Clear result of a full SPI_execute */
4080  if (estate->eval_tuptable != NULL)
4081  SPI_freetuptable(estate->eval_tuptable);
4082  estate->eval_tuptable = NULL;
4083 
4084  /*
4085  * Clear result of exec_eval_simple_expr (but keep the econtext). This
4086  * also clears any short-lived allocations done via get_eval_mcontext.
4087  */
4088  if (estate->eval_econtext != NULL)
4089  ResetExprContext(estate->eval_econtext);
4090 }
4091 
4092 
4093 /* ----------
4094  * Generate a prepared plan
4095  *
4096  * CAUTION: it is possible for this function to throw an error after it has
4097  * built a SPIPlan and saved it in expr->plan. Therefore, be wary of doing
4098  * additional things contingent on expr->plan being NULL. That is, given
4099  * code like
4100  *
4101  * if (query->plan == NULL)
4102  * {
4103  * // okay to put setup code here
4104  * exec_prepare_plan(estate, query, ...);
4105  * // NOT okay to put more logic here
4106  * }
4107  *
4108  * extra steps at the end are unsafe because they will not be executed when
4109  * re-executing the calling statement, if exec_prepare_plan failed the first
4110  * time. This is annoyingly error-prone, but the alternatives are worse.
4111  * ----------
4112  */
4113 static void
4114 exec_prepare_plan(PLpgSQL_execstate *estate,
4115  PLpgSQL_expr *expr, int cursorOptions)
4116 {
4117  SPIPlanPtr plan;
4118  SPIPrepareOptions options;
4119 
4120  /*
4121  * The grammar can't conveniently set expr->func while building the parse
4122  * tree, so make sure it's set before parser hooks need it.
4123  */
4124  expr->func = estate->func;
4125 
4126  /*
4127  * Generate and save the plan
4128  */
4129  memset(&options, 0, sizeof(options));
4130  options.parserSetup = (ParserSetupHook) plpgsql_parser_setup;
4131  options.parserSetupArg = (void *) expr;
4132  options.parseMode = expr->parseMode;
4133  options.cursorOptions = cursorOptions;
4134  plan = SPI_prepare_extended(expr->query, &options);
4135  if (plan == NULL)
4136  elog(ERROR, "SPI_prepare_extended failed for \"%s\": %s",
4137  expr->query, SPI_result_code_string(SPI_result));
4138 
4139  SPI_keepplan(plan);
4140  expr->plan = plan;
4141 
4142  /* Check to see if it's a simple expression */
4143  exec_simple_check_plan(estate, expr);
4144 }
4145 
4146 
4147 /* ----------
4148  * exec_stmt_execsql Execute an SQL statement (possibly with INTO).
4149  *
4150  * Note: some callers rely on this not touching stmt_mcontext. If it ever
4151  * needs to use that, fix those callers to push/pop stmt_mcontext.
4152  * ----------
4153  */
4154 static int
4155 exec_stmt_execsql(PLpgSQL_execstate *estate,
4156  PLpgSQL_stmt_execsql *stmt)
4157 {
4158  ParamListInfo paramLI;
4159  long tcount;
4160  int rc;
4161  PLpgSQL_expr *expr = stmt->sqlstmt;
4162  int too_many_rows_level = 0;
4163 
4164  if (plpgsql_extra_errors & PLPGSQL_XCHECK_TOOMANYROWS)
4165  too_many_rows_level = ERROR;
4166  else if (plpgsql_extra_warnings & PLPGSQL_XCHECK_TOOMANYROWS)
4167  too_many_rows_level = WARNING;
4168 
4169  /*
4170  * On the first call for this statement generate the plan, and detect
4171  * whether the statement is INSERT/UPDATE/DELETE
4172  */
4173  if (expr->plan == NULL)
4174  exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK);
4175 
4176  if (!stmt->mod_stmt_set)
4177  {
4178  ListCell *l;
4179 
4180  stmt->mod_stmt = false;
4181  foreach(l, SPI_plan_get_plan_sources(expr->plan))
4182  {
4183  CachedPlanSource *plansource = (CachedPlanSource *) lfirst(l);
4184 
4185  /*
4186  * We could look at the raw_parse_tree, but it seems simpler to
4187  * check the command tag. Note we should *not* look at the Query
4188  * tree(s), since those are the result of rewriting and could have
4189  * been transmogrified into something else entirely.
4190  */
4191  if (plansource->commandTag == CMDTAG_INSERT ||
4192  plansource->commandTag == CMDTAG_UPDATE ||
4193  plansource->commandTag == CMDTAG_DELETE)
4194  {
4195  stmt->mod_stmt = true;
4196  break;
4197  }
4198  }
4199  stmt->mod_stmt_set = true;
4200  }
4201 
4202  /*
4203  * Set up ParamListInfo to pass to executor
4204  */
4205  paramLI = setup_param_list(estate, expr);
4206 
4207  /*
4208  * If we have INTO, then we only need one row back ... but if we have INTO
4209  * STRICT or extra check too_many_rows, ask for two rows, so that we can
4210  * verify the statement returns only one. INSERT/UPDATE/DELETE are always
4211  * treated strictly. Without INTO, just run the statement to completion
4212  * (tcount = 0).
4213  *
4214  * We could just ask for two rows always when using INTO, but there are
4215  * some cases where demanding the extra row costs significant time, eg by
4216  * forcing completion of a sequential scan. So don't do it unless we need
4217  * to enforce strictness.
4218  */
4219  if (stmt->into)
4220  {
4221  if (stmt->strict || stmt->mod_stmt || too_many_rows_level)
4222  tcount = 2;
4223  else
4224  tcount = 1;
4225  }
4226  else
4227  tcount = 0;
4228 
4229  /*
4230  * Execute the plan
4231  */
4232  rc = SPI_execute_plan_with_paramlist(expr->plan, paramLI,
4233  estate->readonly_func, tcount);
4234 
4235  /*
4236  * Check for error, and set FOUND if appropriate (for historical reasons
4237  * we set FOUND only for certain query types). Also Assert that we
4238  * identified the statement type the same as SPI did.
4239  */
4240  switch (rc)
4241  {
4242  case SPI_OK_SELECT:
4243  Assert(!stmt->mod_stmt);
4244  exec_set_found(estate, (SPI_processed != 0));
4245  break;
4246 
4247  case SPI_OK_INSERT:
4248  case SPI_OK_UPDATE:
4249  case SPI_OK_DELETE:
4250  case SPI_OK_INSERT_RETURNING:
4251  case SPI_OK_UPDATE_RETURNING:
4252  case SPI_OK_DELETE_RETURNING:
4253  Assert(stmt->mod_stmt);
4254  exec_set_found(estate, (SPI_processed != 0));
4255  break;
4256 
4257  case SPI_OK_SELINTO:
4258  case SPI_OK_UTILITY:
4259  Assert(!stmt->mod_stmt);
4260  break;
4261 
4262  case SPI_OK_REWRITTEN:
4263 
4264  /*
4265  * The command was rewritten into another kind of command. It's
4266  * not clear what FOUND would mean in that case (and SPI doesn't
4267  * return the row count either), so just set it to false. Note
4268  * that we can't assert anything about mod_stmt here.
4269  */
4270  exec_set_found(estate, false);
4271  break;
4272 
4273  /* Some SPI errors deserve specific error messages */
4274  case SPI_ERROR_COPY:
4275  ereport(ERROR,
4276  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4277  errmsg("cannot COPY to/from client in PL/pgSQL")));
4278  break;
4279 
4280  case SPI_ERROR_TRANSACTION:
4281  ereport(ERROR,
4282  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4283  errmsg("unsupported transaction command in PL/pgSQL")));
4284  break;
4285 
4286  default:
4287  elog(ERROR, "SPI_execute_plan_with_paramlist failed executing query \"%s\": %s",
4288  expr->query, SPI_result_code_string(rc));
4289  break;
4290  }
4291 
4292  /* All variants should save result info for GET DIAGNOSTICS */
4293  estate->eval_processed = SPI_processed;
4294 
4295  /* Process INTO if present */
4296  if (stmt->into)
4297  {
4298  SPITupleTable *tuptab = SPI_tuptable;
4299  uint64 n = SPI_processed;
4300  PLpgSQL_variable *target;
4301 
4302  /* If the statement did not return a tuple table, complain */
4303  if (tuptab == NULL)
4304  ereport(ERROR,
4305  (errcode(ERRCODE_SYNTAX_ERROR),
4306  errmsg("INTO used with a command that cannot return data")));
4307 
4308  /* Fetch target's datum entry */
4309  target = (PLpgSQL_variable *) estate->datums[stmt->target->dno];
4310 
4311  /*
4312  * If SELECT ... INTO specified STRICT, and the query didn't find
4313  * exactly one row, throw an error. If STRICT was not specified, then
4314  * allow the query to find any number of rows.
4315  */
4316  if (n == 0)
4317  {
4318  if (stmt->strict)
4319  {
4320  char *errdetail;
4321 
4322  if (estate->func->print_strict_params)
4323  errdetail = format_expr_params(estate, expr);
4324  else
4325  errdetail = NULL;
4326 
4327  ereport(ERROR,
4328  (errcode(ERRCODE_NO_DATA_FOUND),
4329  errmsg("query returned no rows"),
4330  errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
4331  }
4332  /* set the target to NULL(s) */
4333  exec_move_row(estate, target, NULL, tuptab->tupdesc);
4334  }
4335  else
4336  {
4337  if (n > 1 && (stmt->strict || stmt->mod_stmt || too_many_rows_level))
4338  {
4339  char *errdetail;
4340  int errlevel;
4341 
4342  if (estate->func->print_strict_params)
4343  errdetail = format_expr_params(estate, expr);
4344  else
4345  errdetail = NULL;
4346 
4347  errlevel = (stmt->strict || stmt->mod_stmt) ? ERROR : too_many_rows_level;
4348 
4349  ereport(errlevel,
4350  (errcode(ERRCODE_TOO_MANY_ROWS),
4351  errmsg("query returned more than one row"),
4352  errdetail ? errdetail_internal("parameters: %s", errdetail) : 0,
4353  errhint("Make sure the query returns a single row, or use LIMIT 1.")));
4354  }
4355  /* Put the first result row into the target */
4356  exec_move_row(estate, target, tuptab->vals[0], tuptab->tupdesc);
4357  }
4358 
4359  /* Clean up */
4360  exec_eval_cleanup(estate);
4361  SPI_freetuptable(SPI_tuptable);
4362  }
4363  else
4364  {
4365  /* If the statement returned a tuple table, complain */
4366  if (SPI_tuptable != NULL)
4367  ereport(ERROR,
4368  (errcode(ERRCODE_SYNTAX_ERROR),
4369  errmsg("query has no destination for result data"),
4370  (rc == SPI_OK_SELECT) ? errhint("If you want to discard the results of a SELECT, use PERFORM instead.") : 0));
4371  }
4372 
4373  return PLPGSQL_RC_OK;
4374 }
4375 
4376 
4377 /* ----------
4378  * exec_stmt_dynexecute Execute a dynamic SQL query
4379  * (possibly with INTO).
4380  * ----------
4381  */
4382 static int
4383 exec_stmt_dynexecute(PLpgSQL_execstate *estate,
4384  PLpgSQL_stmt_dynexecute *stmt)
4385 {
4386  Datum query;
4387  bool isnull;
4388  Oid restype;
4389  int32 restypmod;
4390  char *querystr;
4391  int exec_res;
4392  ParamListInfo paramLI;
4393  SPIExecuteOptions options;
4394  MemoryContext stmt_mcontext = get_stmt_mcontext(estate);
4395 
4396  /*
4397  * First we evaluate the string expression after the EXECUTE keyword. Its
4398  * result is the querystring we have to execute.
4399  */
4400  query = exec_eval_expr(estate, stmt->query, &isnull, &restype, &restypmod);
4401  if (isnull)
4402  ereport(ERROR,
4403  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
4404  errmsg("query string argument of EXECUTE is null")));
4405 
4406  /* Get the C-String representation */
4407  querystr = convert_value_to_string(estate, query, restype);
4408 
4409  /* copy it into the stmt_mcontext before we clean up */
4410  querystr = MemoryContextStrdup(stmt_mcontext, querystr);
4411 
4412  exec_eval_cleanup(estate);
4413 
4414  /*
4415  * Execute the query without preparing a saved plan.
4416  */
4417  paramLI = exec_eval_using_params(estate, stmt->params);
4418 
4419  memset(&options, 0, sizeof(options));
4420  options.params = paramLI;
4421  options.read_only = estate->readonly_func;
4422 
4423  exec_res = SPI_execute_extended(querystr, &options);
4424 
4425  switch (exec_res)
4426  {
4427  case SPI_OK_SELECT:
4428  case SPI_OK_INSERT:
4429  case SPI_OK_UPDATE:
4430  case SPI_OK_DELETE:
4431  case SPI_OK_INSERT_RETURNING:
4432  case SPI_OK_UPDATE_RETURNING:
4433  case SPI_OK_DELETE_RETURNING:
4434  case SPI_OK_UTILITY:
4435  case SPI_OK_REWRITTEN:
4436  break;
4437 
4438  case 0:
4439 
4440  /*
4441  * Also allow a zero return, which implies the querystring
4442  * contained no commands.
4443  */
4444  break;
4445 
4446  case SPI_OK_SELINTO:
4447 
4448  /*
4449  * We want to disallow SELECT INTO for now, because its behavior
4450  * is not consistent with SELECT INTO in a normal plpgsql context.
4451  * (We need to reimplement EXECUTE to parse the string as a
4452  * plpgsql command, not just feed it to SPI_execute.) This is not
4453  * a functional limitation because CREATE TABLE AS is allowed.
4454  */
4455  ereport(ERROR,
4456  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4457  errmsg("EXECUTE of SELECT ... INTO is not implemented"),
4458  errhint("You might want to use EXECUTE ... INTO or EXECUTE CREATE TABLE ... AS instead.")));
4459  break;
4460 
4461  /* Some SPI errors deserve specific error messages */
4462  case SPI_ERROR_COPY:
4463  ereport(ERROR,
4464  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4465  errmsg("cannot COPY to/from client in PL/pgSQL")));
4466  break;
4467 
4468  case SPI_ERROR_TRANSACTION:
4469  ereport(ERROR,
4470  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4471  errmsg("EXECUTE of transaction commands is not implemented")));
4472  break;
4473 
4474  default:
4475  elog(ERROR, "SPI_execute_extended failed executing query \"%s\": %s",
4476  querystr, SPI_result_code_string(exec_res));
4477  break;
4478  }
4479 
4480  /* Save result info for GET DIAGNOSTICS */
4481  estate->eval_processed = SPI_processed;
4482 
4483  /* Process INTO if present */
4484  if (stmt->into)
4485  {
4486  SPITupleTable *tuptab = SPI_tuptable;
4487  uint64 n = SPI_processed;
4488  PLpgSQL_variable *target;
4489 
4490  /* If the statement did not return a tuple table, complain */
4491  if (tuptab == NULL)
4492  ereport(ERROR,
4493  (errcode(ERRCODE_SYNTAX_ERROR),
4494  errmsg("INTO used with a command that cannot return data")));
4495 
4496  /* Fetch target's datum entry */
4497  target = (PLpgSQL_variable *) estate->datums[stmt->target->dno];
4498 
4499  /*
4500  * If SELECT ... INTO specified STRICT, and the query didn't find
4501  * exactly one row, throw an error. If STRICT was not specified, then
4502  * allow the query to find any number of rows.
4503  */
4504  if (n == 0)
4505  {
4506  if (stmt->strict)
4507  {
4508  char *errdetail;
4509 
4510  if (estate->func->print_strict_params)
4511  errdetail = format_preparedparamsdata(estate, paramLI);
4512  else
4513  errdetail = NULL;
4514 
4515  ereport(ERROR,
4516  (errcode(ERRCODE_NO_DATA_FOUND),
4517  errmsg("query returned no rows"),
4518  errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
4519  }
4520  /* set the target to NULL(s) */
4521  exec_move_row(estate, target, NULL, tuptab->tupdesc);
4522  }
4523  else
4524  {
4525  if (n > 1 && stmt->strict)
4526  {
4527  char *errdetail;
4528 
4529  if (estate->func->print_strict_params)
4530  errdetail = format_preparedparamsdata(estate, paramLI);
4531  else
4532  errdetail = NULL;
4533 
4534  ereport(ERROR,
4535  (errcode(ERRCODE_TOO_MANY_ROWS),
4536  errmsg("query returned more than one row"),
4537  errdetail ? errdetail_internal("parameters: %s", errdetail) : 0));
4538  }
4539 
4540  /* Put the first result row into the target */
4541  exec_move_row(estate, target, tuptab->vals[0], tuptab->tupdesc);
4542  }
4543  /* clean up after exec_move_row() */
4544  exec_eval_cleanup(estate);
4545  }
4546  else
4547  {
4548  /*
4549  * It might be a good idea to raise an error if the query returned
4550  * tuples that are being ignored, but historically we have not done
4551  * that.
4552  */
4553  }
4554 
4555  /* Release any result from SPI_execute, as well as transient data */
4556  SPI_freetuptable(SPI_tuptable);
4557  MemoryContextReset(stmt_mcontext);
4558 
4559  return PLPGSQL_RC_OK;
4560 }
4561 
4562 
4563 /* ----------
4564  * exec_stmt_dynfors Execute a dynamic query, assign each
4565  * tuple to a record or row and
4566  * execute a group of statements
4567  * for it.
4568  * ----------
4569  */
4570 static int
4571 exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt)
4572 {
4573  Portal portal;
4574  int rc;
4575 
4576  portal = exec_dynquery_with_params(estate, stmt->query, stmt->params,
4577  NULL, CURSOR_OPT_NO_SCROLL);
4578 
4579  /*
4580  * Execute the loop
4581  */
4582  rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, true);
4583 
4584  /*
4585  * Close the implicit cursor
4586  */
4587  SPI_cursor_close(portal);
4588 
4589  return rc;
4590 }
4591 
4592 
4593 /* ----------
4594  * exec_stmt_open Execute an OPEN cursor statement
4595  * ----------
4596  */
4597 static int
4598 exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt)
4599 {
4600  PLpgSQL_var *curvar;
4601  MemoryContext stmt_mcontext = NULL;
4602  char *curname = NULL;
4603  PLpgSQL_expr *query;
4604  Portal portal;
4605  ParamListInfo paramLI;
4606 
4607  /* ----------
4608  * Get the cursor variable and if it has an assigned name, check
4609  * that it's not in use currently.
4610  * ----------
4611  */
4612  curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]);
4613  if (!curvar->isnull)
4614  {
4615  MemoryContext oldcontext;
4616 
4617  /* We only need stmt_mcontext to hold the cursor name string */
4618  stmt_mcontext = get_stmt_mcontext(estate);
4619  oldcontext = MemoryContextSwitchTo(stmt_mcontext);
4620  curname = TextDatumGetCString(curvar->value);
4621  MemoryContextSwitchTo(oldcontext);
4622 
4623  if (SPI_cursor_find(curname) != NULL)
4624  ereport(ERROR,
4625  (errcode(ERRCODE_DUPLICATE_CURSOR),
4626  errmsg("cursor \"%s\" already in use", curname)));
4627  }
4628 
4629  /* ----------
4630  * Process the OPEN according to it's type.
4631  * ----------
4632  */
4633  if (stmt->query != NULL)
4634  {
4635  /* ----------
4636  * This is an OPEN refcursor FOR SELECT ...
4637  *
4638  * We just make sure the query is planned. The real work is
4639  * done downstairs.
4640  * ----------
4641  */
4642  query = stmt->query;
4643  if (query->plan == NULL)
4644  exec_prepare_plan(estate, query, stmt->cursor_options);
4645  }
4646  else if (stmt->dynquery != NULL)
4647  {
4648  /* ----------
4649  * This is an OPEN refcursor FOR EXECUTE ...
4650  * ----------
4651  */
4652  portal = exec_dynquery_with_params(estate,
4653  stmt->dynquery,
4654  stmt->params,
4655  curname,
4656  stmt->cursor_options);
4657 
4658  /*
4659  * If cursor variable was NULL, store the generated portal name in it.
4660  * Note: exec_dynquery_with_params already reset the stmt_mcontext, so
4661  * curname is a dangling pointer here; but testing it for nullness is
4662  * OK.
4663  */
4664  if (curname == NULL)
4665  assign_text_var(estate, curvar, portal->name);
4666 
4667  return PLPGSQL_RC_OK;
4668  }
4669  else
4670  {
4671  /* ----------
4672  * This is an OPEN cursor
4673  *
4674  * Note: parser should already have checked that statement supplies
4675  * args iff cursor needs them, but we check again to be safe.
4676  * ----------
4677  */
4678  if (stmt->argquery != NULL)
4679  {
4680  /* ----------
4681  * OPEN CURSOR with args. We fake a SELECT ... INTO ...
4682  * statement to evaluate the args and put 'em into the
4683  * internal row.
4684  * ----------
4685  */
4686  PLpgSQL_stmt_execsql set_args;
4687 
4688  if (curvar->cursor_explicit_argrow < 0)
4689  ereport(ERROR,
4690  (errcode(ERRCODE_SYNTAX_ERROR),
4691  errmsg("arguments given for cursor without arguments")));
4692 
4693  memset(&set_args, 0, sizeof(set_args));
4694  set_args.cmd_type = PLPGSQL_STMT_EXECSQL;
4695  set_args.lineno = stmt->lineno;
4696  set_args.sqlstmt = stmt->argquery;
4697  set_args.into = true;
4698  /* XXX historically this has not been STRICT */
4699  set_args.target = (PLpgSQL_variable *)
4700  (estate->datums[curvar->cursor_explicit_argrow]);
4701 
4702  if (exec_stmt_execsql(estate, &set_args) != PLPGSQL_RC_OK)
4703  elog(ERROR, "open cursor failed during argument processing");
4704  }
4705  else
4706  {
4707  if (curvar->cursor_explicit_argrow >= 0)
4708  ereport(ERROR,
4709  (errcode(ERRCODE_SYNTAX_ERROR),
4710  errmsg("arguments required for cursor")));
4711  }
4712 
4713  query = curvar->cursor_explicit_expr;
4714  if (query->plan == NULL)
4715  exec_prepare_plan(estate, query, curvar->cursor_options);
4716  }
4717 
4718  /*
4719  * Set up ParamListInfo for this query
4720  */
4721  paramLI = setup_param_list(estate, query);
4722 
4723  /*
4724  * Open the cursor (the paramlist will get copied into the portal)
4725  */
4726  portal = SPI_cursor_open_with_paramlist(curname, query->plan,
4727  paramLI,
4728  estate->readonly_func);
4729  if (portal == NULL)
4730  elog(ERROR, "could not open cursor: %s",
4731  SPI_result_code_string(SPI_result));
4732 
4733  /*
4734  * If cursor variable was NULL, store the generated portal name in it
4735  */
4736  if (curname == NULL)
4737  assign_text_var(estate, curvar, portal->name);
4738 
4739  /* If we had any transient data, clean it up */
4740  exec_eval_cleanup(estate);
4741  if (stmt_mcontext)
4742  MemoryContextReset(stmt_mcontext);
4743 
4744  return PLPGSQL_RC_OK;
4745 }
4746 
4747 
4748 /* ----------
4749  * exec_stmt_fetch Fetch from a cursor into a target, or just
4750  * move the current position of the cursor
4751  * ----------
4752  */
4753 static int
4754 exec_stmt_fetch(PLpgSQL_execstate *estate, PLpgSQL_stmt_fetch *stmt)
4755 {
4756  PLpgSQL_var *curvar;
4757  long how_many = stmt->how_many;
4758  SPITupleTable *tuptab;
4759  Portal portal;
4760  char *curname;
4761  uint64 n;
4762  MemoryContext oldcontext;
4763 
4764  /* ----------
4765  * Get the portal of the cursor by name
4766  * ----------
4767  */
4768  curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]);
4769  if (curvar->isnull)
4770  ereport(ERROR,
4771  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
4772  errmsg("cursor variable \"%s\" is null", curvar->refname)));
4773 
4774  /* Use eval_mcontext for short-lived string */
4775  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
4776  curname = TextDatumGetCString(curvar->value);
4777  MemoryContextSwitchTo(oldcontext);
4778 
4779  portal = SPI_cursor_find(curname);
4780  if (portal == NULL)
4781  ereport(ERROR,
4782  (errcode(ERRCODE_UNDEFINED_CURSOR),
4783  errmsg("cursor \"%s\" does not exist", curname)));
4784 
4785  /* Calculate position for FETCH_RELATIVE or FETCH_ABSOLUTE */
4786  if (stmt->expr)
4787  {
4788  bool isnull;
4789 
4790  /* XXX should be doing this in LONG not INT width */
4791  how_many = exec_eval_integer(estate, stmt->expr, &isnull);
4792 
4793  if (isnull)
4794  ereport(ERROR,
4795  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
4796  errmsg("relative or absolute cursor position is null")));
4797 
4798  exec_eval_cleanup(estate);
4799  }
4800 
4801  if (!stmt->is_move)
4802  {
4803  PLpgSQL_variable *target;
4804 
4805  /* ----------
4806  * Fetch 1 tuple from the cursor
4807  * ----------
4808  */
4809  SPI_scroll_cursor_fetch(portal, stmt->direction, how_many);
4810  tuptab = SPI_tuptable;
4811  n = SPI_processed;
4812 
4813  /* ----------
4814  * Set the target appropriately.
4815  * ----------
4816  */
4817  target = (PLpgSQL_variable *) estate->datums[stmt->target->dno];
4818  if (n == 0)
4819  exec_move_row(estate, target, NULL, tuptab->tupdesc);
4820  else
4821  exec_move_row(estate, target, tuptab->vals[0], tuptab->tupdesc);
4822 
4823  exec_eval_cleanup(estate);
4824  SPI_freetuptable(tuptab);
4825  }
4826  else
4827  {
4828  /* Move the cursor */
4829  SPI_scroll_cursor_move(portal, stmt->direction, how_many);
4830  n = SPI_processed;
4831  }
4832 
4833  /* Set the ROW_COUNT and the global FOUND variable appropriately. */
4834  estate->eval_processed = n;
4835  exec_set_found(estate, n != 0);
4836 
4837  return PLPGSQL_RC_OK;
4838 }
4839 
4840 /* ----------
4841  * exec_stmt_close Close a cursor
4842  * ----------
4843  */
4844 static int
4845 exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
4846 {
4847  PLpgSQL_var *curvar;
4848  Portal portal;
4849  char *curname;
4850  MemoryContext oldcontext;
4851 
4852  /* ----------
4853  * Get the portal of the cursor by name
4854  * ----------
4855  */
4856  curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]);
4857  if (curvar->isnull)
4858  ereport(ERROR,
4859  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
4860  errmsg("cursor variable \"%s\" is null", curvar->refname)));
4861 
4862  /* Use eval_mcontext for short-lived string */
4863  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
4864  curname = TextDatumGetCString(curvar->value);
4865  MemoryContextSwitchTo(oldcontext);
4866 
4867  portal = SPI_cursor_find(curname);
4868  if (portal == NULL)
4869  ereport(ERROR,
4870  (errcode(ERRCODE_UNDEFINED_CURSOR),
4871  errmsg("cursor \"%s\" does not exist", curname)));
4872 
4873  /* ----------
4874  * And close it.
4875  * ----------
4876  */
4877  SPI_cursor_close(portal);
4878 
4879  return PLPGSQL_RC_OK;
4880 }
4881 
4882 /*
4883  * exec_stmt_commit
4884  *
4885  * Commit the transaction.
4886  */
4887 static int
4888 exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
4889 {
4890  if (stmt->chain)
4891  SPI_commit_and_chain();
4892  else
4893  {
4894  SPI_commit();
4895  SPI_start_transaction();
4896  }
4897 
4898  /*
4899  * We need to build new simple-expression infrastructure, since the old
4900  * data structures are gone.
4901  */
4902  estate->simple_eval_estate = NULL;
4903  estate->simple_eval_resowner = NULL;
4904  plpgsql_create_econtext(estate);
4905 
4906  return PLPGSQL_RC_OK;
4907 }
4908 
4909 /*
4910  * exec_stmt_rollback
4911  *
4912  * Abort the transaction.
4913  */
4914 static int
4915 exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
4916 {
4917  if (stmt->chain)
4918  SPI_rollback_and_chain();
4919  else
4920  {
4921  SPI_rollback();
4922  SPI_start_transaction();
4923  }
4924 
4925  /*
4926  * We need to build new simple-expression infrastructure, since the old
4927  * data structures are gone.
4928  */
4929  estate->simple_eval_estate = NULL;
4930  estate->simple_eval_resowner = NULL;
4931  plpgsql_create_econtext(estate);
4932 
4933  return PLPGSQL_RC_OK;
4934 }
4935 
4936 /* ----------
4937  * exec_assign_expr Put an expression's result into a variable.
4938  * ----------
4939  */
4940 static void
4941 exec_assign_expr(PLpgSQL_execstate *estate, PLpgSQL_datum *target,
4942  PLpgSQL_expr *expr)
4943 {
4944  Datum value;
4945  bool isnull;
4946  Oid valtype;
4947  int32 valtypmod;
4948 
4949  /*
4950  * If first time through, create a plan for this expression.
4951  */
4952  if (expr->plan == NULL)
4953  {
4954  /*
4955  * Mark the expression as being an assignment source, if target is a
4956  * simple variable. (This is a bit messy, but it seems cleaner than
4957  * modifying the API of exec_prepare_plan for the purpose. We need to
4958  * stash the target dno into the expr anyway, so that it will be
4959  * available if we have to replan.)
4960  */
4961  if (target->dtype == PLPGSQL_DTYPE_VAR)
4962  expr->target_param = target->dno;
4963  else
4964  expr->target_param = -1; /* should be that already */
4965 
4966  exec_prepare_plan(estate, expr, 0);
4967  }
4968 
4969  value = exec_eval_expr(estate, expr, &isnull, &valtype, &valtypmod);
4970  exec_assign_value(estate, target, value, isnull, valtype, valtypmod);
4971  exec_eval_cleanup(estate);
4972 }
4973 
4974 
4975 /* ----------
4976  * exec_assign_c_string Put a C string into a text variable.
4977  *
4978  * We take a NULL pointer as signifying empty string, not SQL null.
4979  *
4980  * As with the underlying exec_assign_value, caller is expected to do
4981  * exec_eval_cleanup later.
4982  * ----------
4983  */
4984 static void
4985 exec_assign_c_string(PLpgSQL_execstate *estate, PLpgSQL_datum *target,
4986  const char *str)
4987 {
4988  text *value;
4989  MemoryContext oldcontext;
4990 
4991  /* Use eval_mcontext for short-lived text value */
4992  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
4993  if (str != NULL)
4994  value = cstring_to_text(str);
4995  else
4996  value = cstring_to_text("");
4997  MemoryContextSwitchTo(oldcontext);
4998 
4999  exec_assign_value(estate, target, PointerGetDatum(value), false,
5000  TEXTOID, -1);
5001 }
5002 
5003 
5004 /* ----------
5005  * exec_assign_value Put a value into a target datum
5006  *
5007  * Note: in some code paths, this will leak memory in the eval_mcontext;
5008  * we assume that will be cleaned up later by exec_eval_cleanup. We cannot
5009  * call exec_eval_cleanup here for fear of destroying the input Datum value.
5010  * ----------
5011  */
5012 static void
5013 exec_assign_value(PLpgSQL_execstate *estate,
5014  PLpgSQL_datum *target,
5015  Datum value, bool isNull,
5016  Oid valtype, int32 valtypmod)
5017 {
5018  switch (target->dtype)
5019  {
5020  case PLPGSQL_DTYPE_VAR:
5021  case PLPGSQL_DTYPE_PROMISE:
5022  {
5023  /*
5024  * Target is a variable
5025  */
5026  PLpgSQL_var *var = (PLpgSQL_var *) target;
5027  Datum newvalue;
5028 
5029  newvalue = exec_cast_value(estate,
5030  value,
5031  &isNull,
5032  valtype,
5033  valtypmod,
5034  var->datatype->typoid,
5035  var->datatype->atttypmod);
5036 
5037  if (isNull && var->notnull)
5038  ereport(ERROR,
5039  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5040  errmsg("null value cannot be assigned to variable \"%s\" declared NOT NULL",
5041  var->refname)));
5042 
5043  /*
5044  * If type is by-reference, copy the new value (which is
5045  * probably in the eval_mcontext) into the procedure's main
5046  * memory context. But if it's a read/write reference to an
5047  * expanded object, no physical copy needs to happen; at most
5048  * we need to reparent the object's memory context.
5049  *
5050  * If it's an array, we force the value to be stored in R/W
5051  * expanded form. This wins if the function later does, say,
5052  * a lot of array subscripting operations on the variable, and
5053  * otherwise might lose. We might need to use a different
5054  * heuristic, but it's too soon to tell. Also, are there
5055  * cases where it'd be useful to force non-array values into
5056  * expanded form?
5057  */
5058  if (!var->datatype->typbyval && !isNull)
5059  {
5060  if (var->datatype->typisarray &&
5061  !VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(newvalue)))
5062  {
5063  /* array and not already R/W, so apply expand_array */
5064  newvalue = expand_array(newvalue,
5065  estate->datum_context,
5066  NULL);
5067  }
5068  else
5069  {
5070  /* else transfer value if R/W, else just datumCopy */
5071  newvalue = datumTransfer(newvalue,
5072  false,
5073  var->datatype->typlen);
5074  }
5075  }
5076 
5077  /*
5078  * Now free the old value, if any, and assign the new one. But
5079  * skip the assignment if old and new values are the same.
5080  * Note that for expanded objects, this test is necessary and
5081  * cannot reliably be made any earlier; we have to be looking
5082  * at the object's standard R/W pointer to be sure pointer
5083  * equality is meaningful.
5084  *
5085  * Also, if it's a promise variable, we should disarm the
5086  * promise in any case --- otherwise, assigning null to an
5087  * armed promise variable would fail to disarm the promise.
5088  */
5089  if (var->value != newvalue || var->isnull || isNull)
5090  assign_simple_var(estate, var, newvalue, isNull,
5091  (!var->datatype->typbyval && !isNull));
5092  else
5093  var->promise = PLPGSQL_PROMISE_NONE;
5094  break;
5095  }
5096 
5097  case PLPGSQL_DTYPE_ROW:
5098  {
5099  /*
5100  * Target is a row variable
5101  */
5102  PLpgSQL_row *row = (PLpgSQL_row *) target;
5103 
5104  if (isNull)
5105  {
5106  /* If source is null, just assign nulls to the row */
5107  exec_move_row(estate, (PLpgSQL_variable *) row,
5108  NULL, NULL);
5109  }
5110  else
5111  {
5112  /* Source must be of RECORD or composite type */
5113  if (!type_is_rowtype(valtype))
5114  ereport(ERROR,
5115  (errcode(ERRCODE_DATATYPE_MISMATCH),
5116  errmsg("cannot assign non-composite value to a row variable")));
5117  exec_move_row_from_datum(estate, (PLpgSQL_variable *) row,
5118  value);
5119  }
5120  break;
5121  }
5122 
5123  case PLPGSQL_DTYPE_REC:
5124  {
5125  /*
5126  * Target is a record variable
5127  */
5128  PLpgSQL_rec *rec = (PLpgSQL_rec *) target;
5129 
5130  if (isNull)
5131  {
5132  if (rec->notnull)
5133  ereport(ERROR,
5134  (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5135  errmsg("null value cannot be assigned to variable \"%s\" declared NOT NULL",
5136  rec->refname)));
5137 
5138  /* Set variable to a simple NULL */
5139  exec_move_row(estate, (PLpgSQL_variable *) rec,
5140  NULL, NULL);
5141  }
5142  else
5143  {
5144  /* Source must be of RECORD or composite type */
5145  if (!type_is_rowtype(valtype))
5146  ereport(ERROR,
5147  (errcode(ERRCODE_DATATYPE_MISMATCH),
5148  errmsg("cannot assign non-composite value to a record variable")));
5149  exec_move_row_from_datum(estate, (PLpgSQL_variable *) rec,
5150  value);
5151  }
5152  break;
5153  }
5154 
5155  case PLPGSQL_DTYPE_RECFIELD:
5156  {
5157  /*
5158  * Target is a field of a record
5159  */
5160  PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) target;
5161  PLpgSQL_rec *rec;
5162  ExpandedRecordHeader *erh;
5163 
5164  rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]);
5165  erh = rec->erh;
5166 
5167  /*
5168  * If record variable is NULL, instantiate it if it has a
5169  * named composite type, else complain. (This won't change
5170  * the logical state of the record, but if we successfully
5171  * assign below, the unassigned fields will all become NULLs.)
5172  */
5173  if (erh == NULL)
5174  {
5175  instantiate_empty_record_variable(estate, rec);
5176  erh = rec->erh;
5177  }
5178 
5179  /*
5180  * Look up the field's properties if we have not already, or
5181  * if the tuple descriptor ID changed since last time.
5182  */
5183  if (unlikely(recfield->rectupledescid != erh->er_tupdesc_id))
5184  {
5185  if (!expanded_record_lookup_field(erh,
5186  recfield->fieldname,
5187  &recfield->finfo))
5188  ereport(ERROR,
5189  (errcode(ERRCODE_UNDEFINED_COLUMN),
5190  errmsg("record \"%s\" has no field \"%s\"",
5191  rec->refname, recfield->fieldname)));
5192  recfield->rectupledescid = erh->er_tupdesc_id;
5193  }
5194 
5195  /* We don't support assignments to system columns. */
5196  if (recfield->finfo.fnumber <= 0)
5197  ereport(ERROR,
5198  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5199  errmsg("cannot assign to system column \"%s\"",
5200  recfield->fieldname)));
5201 
5202  /* Cast the new value to the right type, if needed. */
5203  value = exec_cast_value(estate,
5204  value,
5205  &isNull,
5206  valtype,
5207  valtypmod,
5208  recfield->finfo.ftypeid,
5209  recfield->finfo.ftypmod);
5210 
5211  /* And assign it. */
5212  expanded_record_set_field(erh, recfield->finfo.fnumber,
5213  value, isNull, !estate->atomic);
5214  break;
5215  }
5216 
5217  default:
5218  elog(ERROR, "unrecognized dtype: %d", target->dtype);
5219  }
5220 }
5221 
5222 /*
5223  * exec_eval_datum Get current value of a PLpgSQL_datum
5224  *
5225  * The type oid, typmod, value in Datum format, and null flag are returned.
5226  *
5227  * At present this doesn't handle PLpgSQL_expr datums; that's not needed
5228  * because we never pass references to such datums to SPI.
5229  *
5230  * NOTE: the returned Datum points right at the stored value in the case of
5231  * pass-by-reference datatypes. Generally callers should take care not to
5232  * modify the stored value. Some callers intentionally manipulate variables
5233  * referenced by R/W expanded pointers, though; it is those callers'
5234  * responsibility that the results are semantically OK.
5235  *
5236  * In some cases we have to palloc a return value, and in such cases we put
5237  * it into the estate's eval_mcontext.
5238  */
5239 static void
5240 exec_eval_datum(PLpgSQL_execstate *estate,
5241  PLpgSQL_datum *datum,
5242  Oid *typeid,
5243  int32 *typetypmod,
5244  Datum *value,
5245  bool *isnull)
5246 {
5247  MemoryContext oldcontext;
5248 
5249  switch (datum->dtype)
5250  {
5251  case PLPGSQL_DTYPE_PROMISE:
5252  /* fulfill promise if needed, then handle like regular var */
5253  plpgsql_fulfill_promise(estate, (PLpgSQL_var *) datum);
5254 
5255  /* FALL THRU */
5256 
5257  case PLPGSQL_DTYPE_VAR:
5258  {
5259  PLpgSQL_var *var = (PLpgSQL_var *) datum;
5260 
5261  *typeid = var->datatype->typoid;
5262  *typetypmod = var->datatype->atttypmod;
5263  *value = var->value;
5264  *isnull = var->isnull;
5265  break;
5266  }
5267 
5268  case PLPGSQL_DTYPE_ROW:
5269  {
5270  PLpgSQL_row *row = (PLpgSQL_row *) datum;
5271  HeapTuple tup;
5272 
5273  /* We get here if there are multiple OUT parameters */
5274  if (!row->rowtupdesc) /* should not happen */
5275  elog(ERROR, "row variable has no tupdesc");
5276  /* Make sure we have a valid type/typmod setting */
5277  BlessTupleDesc(row->rowtupdesc);
5278  oldcontext = MemoryContextSwitchTo(get_eval_mcontext(estate));
5279  tup = make_tuple_from_row(estate, row, row->rowtupdesc);
5280  if (tup == NULL) /* should not happen */
5281  elog(ERROR, "row not compatible with its own tupdesc");
5282  *typeid = row->rowtupdesc->tdtypeid;
5283  *typetypmod = row->rowtupdesc->tdtypmod;
5284  *value = HeapTupleGetDatum(tup);
5285  *isnull = false;
5286  MemoryContextSwitchTo(oldcontext);
5287  break;
5288  }
5289 
5290  case PLPGSQL_DTYPE_REC:
5291  {
5292  PLpgSQL_rec *rec = (PLpgSQL_rec *) datum;
5293 
5294  if (rec->erh == NULL)
5295  {
5296  /* Treat uninstantiated record as a simple NULL */
5297  *value = (Datum) 0;
5298  *isnull = true;
5299  /* Report variable's declared type */
5300  *typeid = rec->rectypeid;
5301  *typetypmod = -1;
5302  }
5303  else
5304  {
5305  if (ExpandedRecordIsEmpty(rec->erh))
5306  {
5307  /* Empty record is also a NULL */
5308  *value = (Datum) 0;
5309  *isnull = true;
5310  }
5311  else
5312  {
5313  *value = ExpandedRecordGetDatum(rec->erh);
5314  *isnull = false;
5315  }
5316  if (rec->rectypeid != RECORDOID)
5317  {
5318  /* Report variable's declared type, if not RECORD */
5319  *typeid = rec->rectypeid;
5320  *typetypmod = -1;
5321  }
5322  else
5323  {
5324  /* Report record's actual type if declared RECORD */
5325  *typeid = rec->erh->er_typeid;
5326  *typetypmod = rec->erh->er_typmod;
5327  }
5328  }
5329  break;
5330  }
5331 
5332  case PLPGSQL_DTYPE_RECFIELD:
5333  {
5334  PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum;
5335  PLpgSQL_rec *rec;
5336  ExpandedRecordHeader *erh;
5337 
5338  rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]);
5339  erh = rec->erh;
5340 
5341  /*
5342  * If record variable is NULL, instantiate it if it has a
5343  * named composite type, else complain. (This won't change
5344  * the logical state of the record: it's still NULL.)
5345  */
5346  if (erh == NULL)
5347  {
5348  instantiate_empty_record_variable(estate, rec);
5349  erh = rec->erh;
5350  }
5351 
5352  /*
5353  * Look up the field's properties if we have not already, or
5354  * if the tuple descriptor ID changed since last time.
5355  */
5356  if (unlikely(recfield->rectupledescid != erh->er_tupdesc_id))
5357  {
5358  if (!expanded_record_lookup_field(erh,
5359  recfield->fieldname,
5360  &recfield->finfo))
5361  ereport(ERROR,
5362  (errcode(ERRCODE_UNDEFINED_COLUMN),
5363  errmsg("record \"%s\" has no field \"%s\"",
5364  rec->refname, recfield->fieldname)));
5365  recfield->rectupledescid = erh->er_tupdesc_id;
5366  }
5367 
5368  /* Report type data. */
5369  *typeid = recfield->finfo.ftypeid;
5370  *typetypmod = recfield->finfo.ftypmod;
5371 
5372  /* And fetch the field value. */
5373  *value = expanded_record_get_field(erh,
5374  recfield->finfo.fnumber,
5375  isnull);
5376  break;
5377  }
5378 
5379  default:
5380  elog(ERROR, "unrecognized dtype: %d", datum->dtype);
5381  }
5382 }
5383 
5384 /*
5385  * plpgsql_exec_get_datum_type Get datatype of a PLpgSQL_datum
5386  *
5387  * This is the same logic as in exec_eval_datum, but we skip acquiring
5388  * the actual value of the variable. Also, needn't support DTYPE_ROW.
5389  */
5390 Oid
5391 plpgsql_exec_get_datum_type(PLpgSQL_execstate *estate,
5392  PLpgSQL_datum *datum)
5393 {
5394  Oid typeid;
5395 
5396  switch (datum->dtype)
5397  {
5398  case PLPGSQL_DTYPE_VAR:
5399  case PLPGSQL_DTYPE_PROMISE:
5400  {
5401  PLpgSQL_var *var = (PLpgSQL_var *) datum;
5402 
5403  typeid = var->datatype->typoid;
5404  break;
5405  }
5406 
5407  case PLPGSQL_DTYPE_REC:
5408  {
5409  PLpgSQL_rec *rec = (PLpgSQL_rec *) datum;
5410 
5411  if (rec->erh == NULL || rec->rectypeid != RECORDOID)
5412  {
5413  /* Report variable's declared type */
5414  typeid = rec->rectypeid;
5415  }
5416  else
5417  {
5418  /* Report record's actual type if declared RECORD */
5419  typeid = rec->erh->er_typeid;
5420  }
5421  break;
5422  }
5423 
5424  case PLPGSQL_DTYPE_RECFIELD:
5425  {
5426  PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum;
5427  PLpgSQL_rec *rec;
5428 
5429  rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]);
5430 
5431  /*
5432  * If record variable is NULL, instantiate it if it has a
5433  * named composite type, else complain. (This won't change
5434  * the logical state of the record: it's still NULL.)
5435  */
5436  if (rec->erh == NULL)
5437  instantiate_empty_record_variable(estate, rec);
5438 
5439  /*
5440  * Look up the field's properties if we have not already, or
5441  * if the tuple descriptor ID changed since last time.
5442  */
5443  if (unlikely(recfield->rectupledescid != rec->erh->er_tupdesc_id))
5444  {
5445  if (!expanded_record_lookup_field(rec->erh,
5446  recfield->fieldname,
5447  &recfield->finfo))
5448  ereport(ERROR,
5449  (errcode(ERRCODE_UNDEFINED_COLUMN),
5450  errmsg("record \"%s\" has no field \"%s\"",
5451  rec->refname, recfield->fieldname)));
5452  recfield->rectupledescid = rec->erh->er_tupdesc_id;
5453  }
5454 
5455  typeid = recfield->finfo.ftypeid;
5456  break;
5457  }
5458 
5459  default:
5460  elog(ERROR, "unrecognized dtype: %d", datum->dtype);
5461  typeid = InvalidOid; /* keep compiler quiet */
5462  break;
5463  }
5464 
5465  return typeid;
5466 }
5467 
5468 /*
5469  * plpgsql_exec_get_datum_type_info Get datatype etc of a PLpgSQL_datum
5470  *
5471  * An extended version of plpgsql_exec_get_datum_type, which also retrieves the
5472  * typmod and collation of the datum. Note however that we don't report the
5473  * possibly-mutable typmod of RECORD values, but say -1 always.
5474  */
5475 void
5476 plpgsql_exec_get_datum_type_info(PLpgSQL_execstate *estate,
5477  PLpgSQL_datum *datum,
5478  Oid *typeId, int32 *typMod, Oid *collation)
5479 {
5480  switch (datum->dtype)
5481  {
5482  case PLPGSQL_DTYPE_VAR:
5483  case PLPGSQL_DTYPE_PROMISE:
5484  {
5485  PLpgSQL_var *var = (PLpgSQL_var *) datum;
5486 
5487  *typeId = var->datatype->typoid;
5488  *typMod = var->datatype->atttypmod;
5489  *collation = var->datatype->collation;
5490  break;
5491  }
5492 
5493  case PLPGSQL_DTYPE_REC:
5494  {
5495  PLpgSQL_rec *rec = (PLpgSQL_rec *) datum;
5496 
5497  if (rec->erh == NULL || rec->rectypeid != RECORDOID)
5498  {
5499  /* Report variable's declared type */
5500  *typeId = rec->rectypeid;
5501  *typMod = -1;
5502  }
5503  else
5504  {
5505  /* Report record's actual type if declared RECORD */
5506  *typeId = rec->erh->er_typeid;
5507  /* do NOT return the mutable typmod of a RECORD variable */
5508  *typMod = -1;
5509  }
5510  /* composite types are never collatable */
5511  *collation = InvalidOid;
5512  break;
5513  }
5514 
5515  case PLPGSQL_DTYPE_RECFIELD:
5516  {
5517  PLpgSQL_recfield *recfield = (PLpgSQL_recfield *) datum;
5518  PLpgSQL_rec *rec;
5519 
5520  rec = (PLpgSQL_rec *) (estate->datums[recfield->recparentno]);
5521 
5522  /*
5523  * If record variable is NULL, instantiate it if it has a
5524  * named composite type, else complain. (This won't change
5525  * the logical state of the record: it's still NULL.)
5526  */
5527  if (rec->erh == NULL)
5528  instantiate_empty_record_variable(estate, rec);
5529 
5530  /*
5531  * Look up the field's properties if we have not already, or
5532  * if the tuple descriptor ID changed since last time.
5533  */
5534  if (unlikely(recfield->rectupledescid != rec->erh->er_tupdesc_id))
5535  {
5536  if (!expanded_record_lookup_field(rec->erh,
5537  recfield->fieldname,
5538  &recfield->finfo))
5539  ereport(ERROR,
5540  (errcode(ERRCODE_UNDEFINED_COLUMN),
5541  errmsg("record \"%s\" has no field \"%s\"",
5542  rec->refname, recfield->fieldname)));
5543  recfield->rectupledescid = rec->erh->er_tupdesc_id;
5544  }
5545 
5546  *typeId = recfield->finfo.ftypeid;
5547  *typMod = recfield->finfo.ftypmod;
5548  *collation = recfield->finfo.fcollation;
5549  break;
5550  }
5551 
5552  default:
5553  elog(ERROR, "unrecognized dtype: %d", datum->dtype);
5554  *typeId = InvalidOid; /* keep compiler quiet */
5555  *typMod = -1;
5556  *collation = InvalidOid;
5557  break;
5558  }
5559 }
5560 
5561 /* ----------
5562  * exec_eval_integer Evaluate an expression, coerce result to int4
5563  *
5564  * Note we do not do exec_eval_cleanup here; the caller must do it at
5565  * some later point. (We do this because the caller may be holding the
5566  * results of other, pass-by-reference, expression evaluations, such as
5567  * an array value to be subscripted.)
5568  * ----------
5569  */
5570 static int
5571 exec_eval_integer(PLpgSQL_execstate *estate,
5572  PLpgSQL_expr *expr,
5573  bool *isNull)
5574 {
5575  Datum exprdatum;
5576  Oid exprtypeid;
5577  int32 exprtypmod;
5578 
5579  exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid, &exprtypmod);
5580  exprdatum = exec_cast_value(estate, exprdatum, isNull,
5581  exprtypeid, exprtypmod,
5582  INT4OID, -1);
5583  return DatumGetInt32(exprdatum);
5584 }
5585 
5586 /* ----------
5587  * exec_eval_boolean Evaluate an expression, coerce result to bool
5588  *
5589  * Note we do not do exec_eval_cleanup here; the caller must do it at
5590  * some later point.
5591  * ----------
5592  */
5593 static bool
5594 exec_eval_boolean(PLpgSQL_execstate *estate,
5595  PLpgSQL_expr *expr,
5596  bool *isNull)
5597 {
5598  Datum exprdatum;
5599  Oid exprtypeid;
5600  int32 exprtypmod;
5601 
5602  exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid, &exprtypmod);
5603  exprdatum = exec_cast_value(estate, exprdatum, isNull,
5604  exprtypeid, exprtypmod,
5605  BOOLOID, -1);
5606  return DatumGetBool(exprdatum);
5607 }
5608 
5609 /* ----------
5610  * exec_eval_expr Evaluate an expression and return
5611  * the result Datum, along with data type/typmod.
5612  *
5613  * NOTE: caller must do exec_eval_cleanup when done with the Datum.
5614  * ----------
5615  */
5616 static Datum
5617 exec_eval_expr(PLpgSQL_execstate *estate,
5618  PLpgSQL_expr *expr,
5619  bool *isNull,
5620  Oid *rettype,
5621  int32 *rettypmod)
5622 {
5623  Datum result = 0;
5624  int rc;
5625  Form_pg_attribute attr;
5626 
5627  /*
5628  * If first time through, create a plan for this expression.
5629  */
5630  if (expr->plan == NULL)
5631  exec_prepare_plan(estate, expr, CURSOR_OPT_PARALLEL_OK);
5632 
5633  /*
5634  * If this is a simple expression, bypass SPI and use the executor
5635  * directly
5636  */
5637  if (exec_eval_simple_expr(estate, expr,
5638  &result, isNull, rettype, rettypmod))
5639  return result;
5640 
5641  /*
5642  * Else do it the hard way via exec_run_select
5643  */
5644  rc = exec_run_select(estate, expr, 2, NULL);
5645  if (rc != SPI_OK_SELECT)
5646  ereport(ERROR,
5647  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
5648  errmsg("query did not return data"),
5649  errcontext("query: %s", expr->query)));
5650 
5651  /*
5652  * Check that the expression returns exactly one column...
5653  */
5654  if (estate->eval_tuptable->tupdesc->natts != 1)
5655  ereport(ERROR,
5656  (errcode(ERRCODE_SYNTAX_ERROR),
5657  errmsg_plural("query returned %d column",
5658  "query returned %d columns",
5659  estate->eval_tuptable->tupdesc->natts,
5660  estate->eval_tuptable->tupdesc->natts),
5661  errcontext("query: %s", expr->query)));
5662 
5663  /*
5664  * ... and get the column's datatype.
5665  */
5666  attr = TupleDescAttr(estate->eval_tuptable->tupdesc, 0);
5667  *rettype = attr->atttypid;
5668  *rettypmod = attr->atttypmod;
5669 
5670  /*
5671  * If there are no rows selected, the result is a N