PostgreSQL Source Code  git master
pl_handler.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pl_handler.c - Handler for the PL/pgSQL
4  * procedural language
5  *
6  * Portions Copyright (c) 1996-2018, 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_handler.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 
16 #include "postgres.h"
17 
18 #include "access/htup_details.h"
19 #include "catalog/pg_proc.h"
20 #include "catalog/pg_type.h"
21 #include "funcapi.h"
22 #include "miscadmin.h"
23 #include "utils/builtins.h"
24 #include "utils/guc.h"
25 #include "utils/lsyscache.h"
26 #include "utils/syscache.h"
27 #include "utils/varlena.h"
28 
29 #include "plpgsql.h"
30 
31 
32 static bool plpgsql_extra_checks_check_hook(char **newvalue, void **extra, GucSource source);
33 static void plpgsql_extra_warnings_assign_hook(const char *newvalue, void *extra);
34 static void plpgsql_extra_errors_assign_hook(const char *newvalue, void *extra);
35 
37 
38 /* Custom GUC variable */
40  {"error", PLPGSQL_RESOLVE_ERROR, false},
41  {"use_variable", PLPGSQL_RESOLVE_VARIABLE, false},
42  {"use_column", PLPGSQL_RESOLVE_COLUMN, false},
43  {NULL, 0, false}
44 };
45 
47 
49 
51 
56 
57 /* Hook for plugins */
59 
60 
61 static bool
62 plpgsql_extra_checks_check_hook(char **newvalue, void **extra, GucSource source)
63 {
64  char *rawstring;
65  List *elemlist;
66  ListCell *l;
67  int extrachecks = 0;
68  int *myextra;
69 
70  if (pg_strcasecmp(*newvalue, "all") == 0)
71  extrachecks = PLPGSQL_XCHECK_ALL;
72  else if (pg_strcasecmp(*newvalue, "none") == 0)
73  extrachecks = PLPGSQL_XCHECK_NONE;
74  else
75  {
76  /* Need a modifiable copy of string */
77  rawstring = pstrdup(*newvalue);
78 
79  /* Parse string into list of identifiers */
80  if (!SplitIdentifierString(rawstring, ',', &elemlist))
81  {
82  /* syntax error in list */
83  GUC_check_errdetail("List syntax is invalid.");
84  pfree(rawstring);
85  list_free(elemlist);
86  return false;
87  }
88 
89  foreach(l, elemlist)
90  {
91  char *tok = (char *) lfirst(l);
92 
93  if (pg_strcasecmp(tok, "shadowed_variables") == 0)
94  extrachecks |= PLPGSQL_XCHECK_SHADOWVAR;
95  else if (pg_strcasecmp(tok, "all") == 0 || pg_strcasecmp(tok, "none") == 0)
96  {
97  GUC_check_errdetail("Key word \"%s\" cannot be combined with other key words.", tok);
98  pfree(rawstring);
99  list_free(elemlist);
100  return false;
101  }
102  else
103  {
104  GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
105  pfree(rawstring);
106  list_free(elemlist);
107  return false;
108  }
109  }
110 
111  pfree(rawstring);
112  list_free(elemlist);
113  }
114 
115  myextra = (int *) malloc(sizeof(int));
116  if (!myextra)
117  return false;
118  *myextra = extrachecks;
119  *extra = (void *) myextra;
120 
121  return true;
122 }
123 
124 static void
125 plpgsql_extra_warnings_assign_hook(const char *newvalue, void *extra)
126 {
127  plpgsql_extra_warnings = *((int *) extra);
128 }
129 
130 static void
131 plpgsql_extra_errors_assign_hook(const char *newvalue, void *extra)
132 {
133  plpgsql_extra_errors = *((int *) extra);
134 }
135 
136 
137 /*
138  * _PG_init() - library load-time initialization
139  *
140  * DO NOT make this static nor change its name!
141  */
142 void
143 _PG_init(void)
144 {
145  /* Be sure we do initialization only once (should be redundant now) */
146  static bool inited = false;
147 
148  if (inited)
149  return;
150 
152 
153  DefineCustomEnumVariable("plpgsql.variable_conflict",
154  gettext_noop("Sets handling of conflicts between PL/pgSQL variable names and table column names."),
155  NULL,
158  variable_conflict_options,
159  PGC_SUSET, 0,
160  NULL, NULL, NULL);
161 
162  DefineCustomBoolVariable("plpgsql.print_strict_params",
163  gettext_noop("Print information about parameters in the DETAIL part of the error messages generated on INTO ... STRICT failures."),
164  NULL,
166  false,
167  PGC_USERSET, 0,
168  NULL, NULL, NULL);
169 
170  DefineCustomBoolVariable("plpgsql.check_asserts",
171  gettext_noop("Perform checks given in ASSERT statements."),
172  NULL,
174  true,
175  PGC_USERSET, 0,
176  NULL, NULL, NULL);
177 
178  DefineCustomStringVariable("plpgsql.extra_warnings",
179  gettext_noop("List of programming constructs that should produce a warning."),
180  NULL,
182  "none",
186  NULL);
187 
188  DefineCustomStringVariable("plpgsql.extra_errors",
189  gettext_noop("List of programming constructs that should produce an error."),
190  NULL,
192  "none",
196  NULL);
197 
198  EmitWarningsOnPlaceholders("plpgsql");
199 
203 
204  /* Set up a rendezvous point with optional instrumentation plugin */
205  plpgsql_plugin_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
206 
207  inited = true;
208 }
209 
210 /* ----------
211  * plpgsql_call_handler
212  *
213  * The PostgreSQL function manager and trigger manager
214  * call this function for execution of PL/pgSQL procedures.
215  * ----------
216  */
218 
219 Datum
221 {
222  bool nonatomic;
223  PLpgSQL_function *func;
224  PLpgSQL_execstate *save_cur_estate;
225  Datum retval;
226  int rc;
227 
228  nonatomic = fcinfo->context &&
229  IsA(fcinfo->context, CallContext) &&
230  !castNode(CallContext, fcinfo->context)->atomic;
231 
232  /*
233  * Connect to SPI manager
234  */
235  if ((rc = SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0)) != SPI_OK_CONNECT)
236  elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
237 
238  /* Find or compile the function */
239  func = plpgsql_compile(fcinfo, false);
240 
241  /* Must save and restore prior value of cur_estate */
242  save_cur_estate = func->cur_estate;
243 
244  /* Mark the function as busy, so it can't be deleted from under us */
245  func->use_count++;
246 
247  PG_TRY();
248  {
249  /*
250  * Determine if called as function or trigger and call appropriate
251  * subhandler
252  */
253  if (CALLED_AS_TRIGGER(fcinfo))
255  (TriggerData *) fcinfo->context));
256  else if (CALLED_AS_EVENT_TRIGGER(fcinfo))
257  {
259  (EventTriggerData *) fcinfo->context);
260  retval = (Datum) 0;
261  }
262  else
263  retval = plpgsql_exec_function(func, fcinfo, NULL, !nonatomic);
264  }
265  PG_CATCH();
266  {
267  /* Decrement use-count, restore cur_estate, and propagate error */
268  func->use_count--;
269  func->cur_estate = save_cur_estate;
270  PG_RE_THROW();
271  }
272  PG_END_TRY();
273 
274  func->use_count--;
275 
276  func->cur_estate = save_cur_estate;
277 
278  /*
279  * Disconnect from SPI manager
280  */
281  if ((rc = SPI_finish()) != SPI_OK_FINISH)
282  elog(ERROR, "SPI_finish failed: %s", SPI_result_code_string(rc));
283 
284  return retval;
285 }
286 
287 /* ----------
288  * plpgsql_inline_handler
289  *
290  * Called by PostgreSQL to execute an anonymous code block
291  * ----------
292  */
294 
295 Datum
297 {
299  PLpgSQL_function *func;
300  FunctionCallInfoData fake_fcinfo;
301  FmgrInfo flinfo;
302  EState *simple_eval_estate;
303  Datum retval;
304  int rc;
305 
306  /*
307  * Connect to SPI manager
308  */
309  if ((rc = SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC)) != SPI_OK_CONNECT)
310  elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
311 
312  /* Compile the anonymous code block */
313  func = plpgsql_compile_inline(codeblock->source_text);
314 
315  /* Mark the function as busy, just pro forma */
316  func->use_count++;
317 
318  /*
319  * Set up a fake fcinfo with just enough info to satisfy
320  * plpgsql_exec_function(). In particular note that this sets things up
321  * with no arguments passed.
322  */
323  MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
324  MemSet(&flinfo, 0, sizeof(flinfo));
325  fake_fcinfo.flinfo = &flinfo;
326  flinfo.fn_oid = InvalidOid;
327  flinfo.fn_mcxt = CurrentMemoryContext;
328 
329  /* Create a private EState for simple-expression execution */
330  simple_eval_estate = CreateExecutorState();
331 
332  /* And run the function */
333  PG_TRY();
334  {
335  retval = plpgsql_exec_function(func, &fake_fcinfo, simple_eval_estate, codeblock->atomic);
336  }
337  PG_CATCH();
338  {
339  /*
340  * We need to clean up what would otherwise be long-lived resources
341  * accumulated by the failed DO block, principally cached plans for
342  * statements (which can be flushed with plpgsql_free_function_memory)
343  * and execution trees for simple expressions, which are in the
344  * private EState.
345  *
346  * Before releasing the private EState, we must clean up any
347  * simple_econtext_stack entries pointing into it, which we can do by
348  * invoking the subxact callback. (It will be called again later if
349  * some outer control level does a subtransaction abort, but no harm
350  * is done.) We cheat a bit knowing that plpgsql_subxact_cb does not
351  * pay attention to its parentSubid argument.
352  */
355  0, NULL);
356 
357  /* Clean up the private EState */
358  FreeExecutorState(simple_eval_estate);
359 
360  /* Function should now have no remaining use-counts ... */
361  func->use_count--;
362  Assert(func->use_count == 0);
363 
364  /* ... so we can free subsidiary storage */
366 
367  /* And propagate the error */
368  PG_RE_THROW();
369  }
370  PG_END_TRY();
371 
372  /* Clean up the private EState */
373  FreeExecutorState(simple_eval_estate);
374 
375  /* Function should now have no remaining use-counts ... */
376  func->use_count--;
377  Assert(func->use_count == 0);
378 
379  /* ... so we can free subsidiary storage */
381 
382  /*
383  * Disconnect from SPI manager
384  */
385  if ((rc = SPI_finish()) != SPI_OK_FINISH)
386  elog(ERROR, "SPI_finish failed: %s", SPI_result_code_string(rc));
387 
388  return retval;
389 }
390 
391 /* ----------
392  * plpgsql_validator
393  *
394  * This function attempts to validate a PL/pgSQL function at
395  * CREATE FUNCTION time.
396  * ----------
397  */
399 
400 Datum
402 {
403  Oid funcoid = PG_GETARG_OID(0);
404  HeapTuple tuple;
405  Form_pg_proc proc;
406  char functyptype;
407  int numargs;
408  Oid *argtypes;
409  char **argnames;
410  char *argmodes;
411  bool is_dml_trigger = false;
412  bool is_event_trigger = false;
413  int i;
414 
415  if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
416  PG_RETURN_VOID();
417 
418  /* Get the new function's pg_proc entry */
419  tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
420  if (!HeapTupleIsValid(tuple))
421  elog(ERROR, "cache lookup failed for function %u", funcoid);
422  proc = (Form_pg_proc) GETSTRUCT(tuple);
423 
424  functyptype = get_typtype(proc->prorettype);
425 
426  /* Disallow pseudotype result */
427  /* except for TRIGGER, RECORD, VOID, or polymorphic */
428  if (functyptype == TYPTYPE_PSEUDO)
429  {
430  /* we assume OPAQUE with no arguments means a trigger */
431  if (proc->prorettype == TRIGGEROID ||
432  (proc->prorettype == OPAQUEOID && proc->pronargs == 0))
433  is_dml_trigger = true;
434  else if (proc->prorettype == EVTTRIGGEROID)
435  is_event_trigger = true;
436  else if (proc->prorettype != RECORDOID &&
437  proc->prorettype != VOIDOID &&
438  !IsPolymorphicType(proc->prorettype))
439  ereport(ERROR,
440  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
441  errmsg("PL/pgSQL functions cannot return type %s",
442  format_type_be(proc->prorettype))));
443  }
444 
445  /* Disallow pseudotypes in arguments (either IN or OUT) */
446  /* except for RECORD and polymorphic */
447  numargs = get_func_arg_info(tuple,
448  &argtypes, &argnames, &argmodes);
449  for (i = 0; i < numargs; i++)
450  {
451  if (get_typtype(argtypes[i]) == TYPTYPE_PSEUDO)
452  {
453  if (argtypes[i] != RECORDOID &&
454  !IsPolymorphicType(argtypes[i]))
455  ereport(ERROR,
456  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
457  errmsg("PL/pgSQL functions cannot accept type %s",
458  format_type_be(argtypes[i]))));
459  }
460  }
461 
462  /* Postpone body checks if !check_function_bodies */
464  {
465  FunctionCallInfoData fake_fcinfo;
466  FmgrInfo flinfo;
467  int rc;
468  TriggerData trigdata;
469  EventTriggerData etrigdata;
470 
471  /*
472  * Connect to SPI manager (is this needed for compilation?)
473  */
474  if ((rc = SPI_connect()) != SPI_OK_CONNECT)
475  elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
476 
477  /*
478  * Set up a fake fcinfo with just enough info to satisfy
479  * plpgsql_compile().
480  */
481  MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
482  MemSet(&flinfo, 0, sizeof(flinfo));
483  fake_fcinfo.flinfo = &flinfo;
484  flinfo.fn_oid = funcoid;
485  flinfo.fn_mcxt = CurrentMemoryContext;
486  if (is_dml_trigger)
487  {
488  MemSet(&trigdata, 0, sizeof(trigdata));
489  trigdata.type = T_TriggerData;
490  fake_fcinfo.context = (Node *) &trigdata;
491  }
492  else if (is_event_trigger)
493  {
494  MemSet(&etrigdata, 0, sizeof(etrigdata));
495  etrigdata.type = T_EventTriggerData;
496  fake_fcinfo.context = (Node *) &etrigdata;
497  }
498 
499  /* Test-compile the function */
500  plpgsql_compile(&fake_fcinfo, true);
501 
502  /*
503  * Disconnect from SPI manager
504  */
505  if ((rc = SPI_finish()) != SPI_OK_FINISH)
506  elog(ERROR, "SPI_finish failed: %s", SPI_result_code_string(rc));
507  }
508 
509  ReleaseSysCache(tuple);
510 
511  PG_RETURN_VOID();
512 }
PLpgSQL_function * plpgsql_compile_inline(char *proc_source)
Definition: pl_comp.c:825
#define SPI_OK_CONNECT
Definition: spi.h:50
void plpgsql_free_function_memory(PLpgSQL_function *func)
Definition: pl_funcs.c:741
Definition: fmgr.h:56
#define CALLED_AS_EVENT_TRIGGER(fcinfo)
Definition: event_trigger.h:40
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PG_FUNCTION_INFO_V1(plpgsql_call_handler)
#define GETSTRUCT(TUP)
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void plpgsql_exec_event_trigger(PLpgSQL_function *func, EventTriggerData *trigdata)
Definition: pl_exec.c:1080
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int SPI_connect_ext(int options)
Definition: spi.c:90
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char * plpgsql_extra_warnings_string
Definition: pl_handler.c:52
int SPI_connect(void)
Definition: spi.c:84
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Definition: nodes.h:586
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Definition: fmgr.h:238
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Definition: plpgsql.h:1139
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#define PLPGSQL_XCHECK_SHADOWVAR
Definition: plpgsql.h:1140
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Definition: pl_handler.c:55
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Definition: pgstrcasecmp.c:36
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Definition: pl_handler.c:296
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Definition: guc.c:8107
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Definition: pl_handler.c:401
char * plpgsql_extra_errors_string
Definition: pl_handler.c:53
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Definition: guc.h:105
#define malloc(a)
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Definition: pl_comp.c:136
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Definition: guc.c:8135
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Definition: pl_handler.c:54
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Definition: pl_handler.c:39
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Definition: pl_handler.c:36
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Definition: guc.c:8082
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FormData_pg_proc * Form_pg_proc
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Definition: plpgsql.h:1141
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Definition: pl_exec.c:8010