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-rw-r--r--src/backend/parser/gram.y124
-rw-r--r--src/backend/replication/libpqwalreceiver/libpqwalreceiver.c31
-rw-r--r--src/backend/utils/hash/dynahash.c10
-rw-r--r--src/backend/utils/mmgr/mcxt.c39
-rw-r--r--src/include/libpq/libpq-be-fe-helpers.h74
-rw-r--r--src/include/libpq/libpq-be-fe.h259
-rw-r--r--src/include/utils/palloc.h2
-rw-r--r--src/tools/pgindent/typedefs.list1
8 files changed, 395 insertions, 145 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 73345bb3c70..db43034b9db 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -318,6 +318,11 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <list> opt_qualified_name
%type <boolean> opt_concurrently
%type <dbehavior> opt_drop_behavior
+%type <list> opt_utility_option_list
+%type <list> utility_option_list
+%type <defelt> utility_option_elem
+%type <str> utility_option_name
+%type <node> utility_option_arg
%type <node> alter_column_default opclass_item opclass_drop alter_using
%type <ival> add_drop opt_asc_desc opt_nulls_order
@@ -338,10 +343,6 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
create_extension_opt_item alter_extension_opt_item
%type <ival> opt_lock lock_type cast_context
-%type <str> utility_option_name
-%type <defelt> utility_option_elem
-%type <list> utility_option_list
-%type <node> utility_option_arg
%type <defelt> drop_option
%type <boolean> opt_or_replace opt_no
opt_grant_grant_option
@@ -556,7 +557,6 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <list> generic_option_list alter_generic_option_list
%type <ival> reindex_target_relation reindex_target_all
-%type <list> opt_reindex_option_list
%type <node> copy_generic_opt_arg copy_generic_opt_arg_list_item
%type <defelt> copy_generic_opt_elem
@@ -1141,6 +1141,41 @@ opt_drop_behavior:
| /* EMPTY */ { $$ = DROP_RESTRICT; /* default */ }
;
+opt_utility_option_list:
+ '(' utility_option_list ')' { $$ = $2; }
+ | /* EMPTY */ { $$ = NULL; }
+ ;
+
+utility_option_list:
+ utility_option_elem
+ {
+ $$ = list_make1($1);
+ }
+ | utility_option_list ',' utility_option_elem
+ {
+ $$ = lappend($1, $3);
+ }
+ ;
+
+utility_option_elem:
+ utility_option_name utility_option_arg
+ {
+ $$ = makeDefElem($1, $2, @1);
+ }
+ ;
+
+utility_option_name:
+ NonReservedWord { $$ = $1; }
+ | analyze_keyword { $$ = "analyze"; }
+ | FORMAT_LA { $$ = "format"; }
+ ;
+
+utility_option_arg:
+ opt_boolean_or_string { $$ = (Node *) makeString($1); }
+ | NumericOnly { $$ = (Node *) $1; }
+ | /* EMPTY */ { $$ = NULL; }
+ ;
+
/*****************************************************************************
*
* CALL statement
@@ -2028,18 +2063,12 @@ constraints_set_mode:
* Checkpoint statement
*/
CheckPointStmt:
- CHECKPOINT
+ CHECKPOINT opt_utility_option_list
{
CheckPointStmt *n = makeNode(CheckPointStmt);
$$ = (Node *) n;
- }
- | CHECKPOINT '(' utility_option_list ')'
- {
- CheckPointStmt *n = makeNode(CheckPointStmt);
-
- $$ = (Node *) n;
- n->options = $3;
+ n->options = $2;
}
;
@@ -9354,7 +9383,7 @@ DropTransformStmt: DROP TRANSFORM opt_if_exists FOR Typename LANGUAGE name opt_d
*****************************************************************************/
ReindexStmt:
- REINDEX opt_reindex_option_list reindex_target_relation opt_concurrently qualified_name
+ REINDEX opt_utility_option_list reindex_target_relation opt_concurrently qualified_name
{
ReindexStmt *n = makeNode(ReindexStmt);
@@ -9367,7 +9396,7 @@ ReindexStmt:
makeDefElem("concurrently", NULL, @4));
$$ = (Node *) n;
}
- | REINDEX opt_reindex_option_list SCHEMA opt_concurrently name
+ | REINDEX opt_utility_option_list SCHEMA opt_concurrently name
{
ReindexStmt *n = makeNode(ReindexStmt);
@@ -9380,7 +9409,7 @@ ReindexStmt:
makeDefElem("concurrently", NULL, @4));
$$ = (Node *) n;
}
- | REINDEX opt_reindex_option_list reindex_target_all opt_concurrently opt_single_name
+ | REINDEX opt_utility_option_list reindex_target_all opt_concurrently opt_single_name
{
ReindexStmt *n = makeNode(ReindexStmt);
@@ -9402,10 +9431,6 @@ reindex_target_all:
SYSTEM_P { $$ = REINDEX_OBJECT_SYSTEM; }
| DATABASE { $$ = REINDEX_OBJECT_DATABASE; }
;
-opt_reindex_option_list:
- '(' utility_option_list ')' { $$ = $2; }
- | /* EMPTY */ { $$ = NULL; }
- ;
/*****************************************************************************
*
@@ -11903,13 +11928,13 @@ ClusterStmt:
n->params = $3;
$$ = (Node *) n;
}
- | CLUSTER '(' utility_option_list ')'
+ | CLUSTER opt_utility_option_list
{
ClusterStmt *n = makeNode(ClusterStmt);
n->relation = NULL;
n->indexname = NULL;
- n->params = $3;
+ n->params = $2;
$$ = (Node *) n;
}
/* unparenthesized VERBOSE kept for pre-14 compatibility */
@@ -11919,21 +11944,18 @@ ClusterStmt:
n->relation = $3;
n->indexname = $4;
- n->params = NIL;
if ($2)
- n->params = lappend(n->params, makeDefElem("verbose", NULL, @2));
+ n->params = list_make1(makeDefElem("verbose", NULL, @2));
$$ = (Node *) n;
}
/* unparenthesized VERBOSE kept for pre-17 compatibility */
- | CLUSTER opt_verbose
+ | CLUSTER VERBOSE
{
ClusterStmt *n = makeNode(ClusterStmt);
n->relation = NULL;
n->indexname = NULL;
- n->params = NIL;
- if ($2)
- n->params = lappend(n->params, makeDefElem("verbose", NULL, @2));
+ n->params = list_make1(makeDefElem("verbose", NULL, @2));
$$ = (Node *) n;
}
/* kept for pre-8.3 compatibility */
@@ -11943,9 +11965,8 @@ ClusterStmt:
n->relation = $5;
n->indexname = $3;
- n->params = NIL;
if ($2)
- n->params = lappend(n->params, makeDefElem("verbose", NULL, @2));
+ n->params = list_make1(makeDefElem("verbose", NULL, @2));
$$ = (Node *) n;
}
;
@@ -11996,64 +12017,31 @@ VacuumStmt: VACUUM opt_full opt_freeze opt_verbose opt_analyze opt_vacuum_relati
}
;
-AnalyzeStmt: analyze_keyword opt_verbose opt_vacuum_relation_list
+AnalyzeStmt: analyze_keyword opt_utility_option_list opt_vacuum_relation_list
{
VacuumStmt *n = makeNode(VacuumStmt);
- n->options = NIL;
- if ($2)
- n->options = lappend(n->options,
- makeDefElem("verbose", NULL, @2));
+ n->options = $2;
n->rels = $3;
n->is_vacuumcmd = false;
$$ = (Node *) n;
}
- | analyze_keyword '(' utility_option_list ')' opt_vacuum_relation_list
+ | analyze_keyword VERBOSE opt_vacuum_relation_list
{
VacuumStmt *n = makeNode(VacuumStmt);
- n->options = $3;
- n->rels = $5;
+ n->options = list_make1(makeDefElem("verbose", NULL, @2));
+ n->rels = $3;
n->is_vacuumcmd = false;
$$ = (Node *) n;
}
;
-utility_option_list:
- utility_option_elem
- {
- $$ = list_make1($1);
- }
- | utility_option_list ',' utility_option_elem
- {
- $$ = lappend($1, $3);
- }
- ;
-
analyze_keyword:
ANALYZE
| ANALYSE /* British */
;
-utility_option_elem:
- utility_option_name utility_option_arg
- {
- $$ = makeDefElem($1, $2, @1);
- }
- ;
-
-utility_option_name:
- NonReservedWord { $$ = $1; }
- | analyze_keyword { $$ = "analyze"; }
- | FORMAT_LA { $$ = "format"; }
- ;
-
-utility_option_arg:
- opt_boolean_or_string { $$ = (Node *) makeString($1); }
- | NumericOnly { $$ = (Node *) $1; }
- | /* EMPTY */ { $$ = NULL; }
- ;
-
opt_analyze:
analyze_keyword { $$ = true; }
| /*EMPTY*/ { $$ = false; }
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 886d99951dd..239641bfbb6 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -421,31 +421,22 @@ libpqrcv_identify_system(WalReceiverConn *conn, TimeLineID *primary_tli)
"IDENTIFY_SYSTEM",
WAIT_EVENT_LIBPQWALRECEIVER_RECEIVE);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
- {
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not receive database system identifier and timeline ID from "
"the primary server: %s",
pchomp(PQerrorMessage(conn->streamConn)))));
- }
/*
* IDENTIFY_SYSTEM returns 3 columns in 9.3 and earlier, and 4 columns in
* 9.4 and onwards.
*/
if (PQnfields(res) < 3 || PQntuples(res) != 1)
- {
- int ntuples = PQntuples(res);
- int nfields = PQnfields(res);
-
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid response from primary server"),
errdetail("Could not identify system: got %d rows and %d fields, expected %d rows and %d or more fields.",
- ntuples, nfields, 1, 3)));
- }
+ PQntuples(res), PQnfields(res), 1, 3)));
primary_sysid = pstrdup(PQgetvalue(res, 0, 0));
*primary_tli = pg_strtoint32(PQgetvalue(res, 0, 1));
PQclear(res);
@@ -607,13 +598,10 @@ libpqrcv_startstreaming(WalReceiverConn *conn,
return false;
}
else if (PQresultStatus(res) != PGRES_COPY_BOTH)
- {
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not start WAL streaming: %s",
pchomp(PQerrorMessage(conn->streamConn)))));
- }
PQclear(res);
return true;
}
@@ -721,26 +709,17 @@ libpqrcv_readtimelinehistoryfile(WalReceiverConn *conn,
cmd,
WAIT_EVENT_LIBPQWALRECEIVER_RECEIVE);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
- {
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not receive timeline history file from "
"the primary server: %s",
pchomp(PQerrorMessage(conn->streamConn)))));
- }
if (PQnfields(res) != 2 || PQntuples(res) != 1)
- {
- int ntuples = PQntuples(res);
- int nfields = PQnfields(res);
-
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid response from primary server"),
errdetail("Expected 1 tuple with 2 fields, got %d tuples with %d fields.",
- ntuples, nfields)));
- }
+ PQntuples(res), PQnfields(res))));
*filename = pstrdup(PQgetvalue(res, 0, 0));
*len = PQgetlength(res, 0, 1);
@@ -844,13 +823,10 @@ libpqrcv_receive(WalReceiverConn *conn, char **buffer,
return -1;
}
else
- {
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not receive data from WAL stream: %s",
pchomp(PQerrorMessage(conn->streamConn)))));
- }
}
if (rawlen < -1)
ereport(ERROR,
@@ -974,13 +950,10 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
pfree(cmd.data);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
- {
- PQclear(res);
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("could not create replication slot \"%s\": %s",
slotname, pchomp(PQerrorMessage(conn->streamConn)))));
- }
if (lsn)
*lsn = DatumGetLSN(DirectFunctionCall1Coll(pg_lsn_in, InvalidOid,
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c
index 1ad155d446e..42e9be274fc 100644
--- a/src/backend/utils/hash/dynahash.c
+++ b/src/backend/utils/hash/dynahash.c
@@ -195,6 +195,7 @@ struct HASHHDR
long ssize; /* segment size --- must be power of 2 */
int sshift; /* segment shift = log2(ssize) */
int nelem_alloc; /* number of entries to allocate at once */
+ bool isfixed; /* if true, don't enlarge */
#ifdef HASH_STATISTICS
@@ -227,7 +228,6 @@ struct HTAB
MemoryContext hcxt; /* memory context if default allocator used */
char *tabname; /* table name (for error messages) */
bool isshared; /* true if table is in shared memory */
- bool isfixed; /* if true, don't enlarge */
/* freezing a shared table isn't allowed, so we can keep state here */
bool frozen; /* true = no more inserts allowed */
@@ -618,8 +618,10 @@ hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
}
}
+ /* Set isfixed if requested, but not till after we build initial entries */
if (flags & HASH_FIXED_SIZE)
- hashp->isfixed = true;
+ hctl->isfixed = true;
+
return hashp;
}
@@ -644,6 +646,8 @@ hdefault(HTAB *hashp)
hctl->ssize = DEF_SEGSIZE;
hctl->sshift = DEF_SEGSIZE_SHIFT;
+ hctl->isfixed = false; /* can be enlarged */
+
#ifdef HASH_STATISTICS
hctl->accesses = hctl->collisions = 0;
#endif
@@ -1713,7 +1717,7 @@ element_alloc(HTAB *hashp, int nelem, int freelist_idx)
HASHELEMENT *prevElement;
int i;
- if (hashp->isfixed)
+ if (hctl->isfixed)
return false;
/* Each element has a HASHELEMENT header plus user data. */
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 15fa4d0a55e..ce01dce9861 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -560,9 +560,7 @@ MemoryContextDeleteChildren(MemoryContext context)
* the specified context, since that means it will automatically be freed
* when no longer needed.
*
- * There is no API for deregistering a callback once registered. If you
- * want it to not do anything anymore, adjust the state pointed to by its
- * "arg" to indicate that.
+ * Note that callers can assume this cannot fail.
*/
void
MemoryContextRegisterResetCallback(MemoryContext context,
@@ -578,6 +576,41 @@ MemoryContextRegisterResetCallback(MemoryContext context,
}
/*
+ * MemoryContextUnregisterResetCallback
+ * Undo the effects of MemoryContextRegisterResetCallback.
+ *
+ * This can be used if a callback's effects are no longer required
+ * at some point before the context has been reset/deleted. It is the
+ * caller's responsibility to pfree the callback struct (if needed).
+ *
+ * An assertion failure occurs if the callback was not registered.
+ * We could alternatively define that case as a no-op, but that seems too
+ * likely to mask programming errors such as passing the wrong context.
+ */
+void
+MemoryContextUnregisterResetCallback(MemoryContext context,
+ MemoryContextCallback *cb)
+{
+ MemoryContextCallback *prev,
+ *cur;
+
+ Assert(MemoryContextIsValid(context));
+
+ for (prev = NULL, cur = context->reset_cbs; cur != NULL;
+ prev = cur, cur = cur->next)
+ {
+ if (cur != cb)
+ continue;
+ if (prev)
+ prev->next = cur->next;
+ else
+ context->reset_cbs = cur->next;
+ return;
+ }
+ Assert(false);
+}
+
+/*
* MemoryContextCallResetCallbacks
* Internal function to call all registered callbacks for context.
*/
diff --git a/src/include/libpq/libpq-be-fe-helpers.h b/src/include/libpq/libpq-be-fe-helpers.h
index af13bd6bf3d..1c4a342090c 100644
--- a/src/include/libpq/libpq-be-fe-helpers.h
+++ b/src/include/libpq/libpq-be-fe-helpers.h
@@ -30,17 +30,7 @@
#ifndef LIBPQ_BE_FE_HELPERS_H
#define LIBPQ_BE_FE_HELPERS_H
-/*
- * Despite the name, BUILDING_DLL is set only when building code directly part
- * of the backend. Which also is where libpq isn't allowed to be
- * used. Obviously this doesn't protect against libpq-fe.h getting included
- * otherwise, but perhaps still protects against a few mistakes...
- */
-#ifdef BUILDING_DLL
-#error "libpq may not be used code directly built into the backend"
-#endif
-
-#include "libpq-fe.h"
+#include "libpq/libpq-be-fe.h"
#include "miscadmin.h"
#include "storage/fd.h"
#include "storage/latch.h"
@@ -289,41 +279,30 @@ libpqsrv_exec_params(PGconn *conn,
static inline PGresult *
libpqsrv_get_result_last(PGconn *conn, uint32 wait_event_info)
{
- PGresult *volatile lastResult = NULL;
+ PGresult *lastResult = NULL;
- /* In what follows, do not leak any PGresults on an error. */
- PG_TRY();
+ for (;;)
{
- for (;;)
- {
- /* Wait for, and collect, the next PGresult. */
- PGresult *result;
+ /* Wait for, and collect, the next PGresult. */
+ PGresult *result;
- result = libpqsrv_get_result(conn, wait_event_info);
- if (result == NULL)
- break; /* query is complete, or failure */
+ result = libpqsrv_get_result(conn, wait_event_info);
+ if (result == NULL)
+ break; /* query is complete, or failure */
- /*
- * Emulate PQexec()'s behavior of returning the last result when
- * there are many.
- */
- PQclear(lastResult);
- lastResult = result;
-
- if (PQresultStatus(lastResult) == PGRES_COPY_IN ||
- PQresultStatus(lastResult) == PGRES_COPY_OUT ||
- PQresultStatus(lastResult) == PGRES_COPY_BOTH ||
- PQstatus(conn) == CONNECTION_BAD)
- break;
- }
- }
- PG_CATCH();
- {
+ /*
+ * Emulate PQexec()'s behavior of returning the last result when there
+ * are many.
+ */
PQclear(lastResult);
- PG_RE_THROW();
- }
- PG_END_TRY();
+ lastResult = result;
+ if (PQresultStatus(lastResult) == PGRES_COPY_IN ||
+ PQresultStatus(lastResult) == PGRES_COPY_OUT ||
+ PQresultStatus(lastResult) == PGRES_COPY_BOTH ||
+ PQstatus(conn) == CONNECTION_BAD)
+ break;
+ }
return lastResult;
}
@@ -462,13 +441,21 @@ exit: ;
* This function is intended to be set via PQsetNoticeReceiver() so that
* NOTICE, WARNING, and similar messages from the connection are reported via
* ereport(), instead of being printed to stderr.
+ *
+ * Because this will be called from libpq with a "real" (not wrapped)
+ * PGresult, we need to temporarily ignore libpq-be-fe.h's wrapper macros
+ * for PGresult and also PQresultErrorMessage, and put back the wrappers
+ * afterwards. That's not pretty, but there seems no better alternative.
*/
+#undef PGresult
+#undef PQresultErrorMessage
+
static inline void
libpqsrv_notice_receiver(void *arg, const PGresult *res)
{
- char *message;
+ const char *message;
int len;
- char *prefix = (char *) arg;
+ const char *prefix = (const char *) arg;
/*
* Trim the trailing newline from the message text returned from
@@ -484,4 +471,7 @@ libpqsrv_notice_receiver(void *arg, const PGresult *res)
errmsg_internal("%s: %.*s", prefix, len, message));
}
+#define PGresult libpqsrv_PGresult
+#define PQresultErrorMessage libpqsrv_PQresultErrorMessage
+
#endif /* LIBPQ_BE_FE_HELPERS_H */
diff --git a/src/include/libpq/libpq-be-fe.h b/src/include/libpq/libpq-be-fe.h
new file mode 100644
index 00000000000..e3f796b0230
--- /dev/null
+++ b/src/include/libpq/libpq-be-fe.h
@@ -0,0 +1,259 @@
+/*-------------------------------------------------------------------------
+ *
+ * libpq-be-fe.h
+ * Wrapper functions for using libpq in extensions
+ *
+ * Code built directly into the backend is not allowed to link to libpq
+ * directly. Extension code is allowed to use libpq however. One of the
+ * main risks in doing so is leaking the malloc-allocated structures
+ * returned by libpq, causing a process-lifespan memory leak.
+ *
+ * This file provides wrapper objects to help in building memory-safe code.
+ * A PGresult object wrapped this way acts much as if it were palloc'd:
+ * it will go away when the specified context is reset or deleted.
+ * We might later extend the concept to other objects such as PGconns.
+ *
+ * See also the libpq-be-fe-helpers.h file, which provides additional
+ * facilities built on top of this one.
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/libpq/libpq-be-fe.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef LIBPQ_BE_FE_H
+#define LIBPQ_BE_FE_H
+
+/*
+ * Despite the name, BUILDING_DLL is set only when building code directly part
+ * of the backend. Which also is where libpq isn't allowed to be
+ * used. Obviously this doesn't protect against libpq-fe.h getting included
+ * otherwise, but perhaps still protects against a few mistakes...
+ */
+#ifdef BUILDING_DLL
+#error "libpq may not be used in code directly built into the backend"
+#endif
+
+#include "libpq-fe.h"
+
+/*
+ * Memory-context-safe wrapper object for a PGresult.
+ */
+typedef struct libpqsrv_PGresult
+{
+ PGresult *res; /* the wrapped PGresult */
+ MemoryContext ctx; /* the MemoryContext it's attached to */
+ MemoryContextCallback cb; /* the callback that implements freeing */
+} libpqsrv_PGresult;
+
+
+/*
+ * Wrap the given PGresult in a libpqsrv_PGresult object, so that it will
+ * go away automatically if the current memory context is reset or deleted.
+ *
+ * To avoid potential memory leaks, backend code must always apply this
+ * immediately to the output of any PGresult-yielding libpq function.
+ */
+static inline libpqsrv_PGresult *
+libpqsrv_PQwrap(PGresult *res)
+{
+ libpqsrv_PGresult *bres;
+ MemoryContext ctx = CurrentMemoryContext;
+
+ /* We pass through a NULL result as-is, since there's nothing to free */
+ if (res == NULL)
+ return NULL;
+ /* Attempt to allocate the wrapper ... this had better not throw error */
+ bres = (libpqsrv_PGresult *)
+ MemoryContextAllocExtended(ctx,
+ sizeof(libpqsrv_PGresult),
+ MCXT_ALLOC_NO_OOM);
+ /* If we failed to allocate a wrapper, free the PGresult before failing */
+ if (bres == NULL)
+ {
+ PQclear(res);
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+ }
+ /* Okay, set up the wrapper */
+ bres->res = res;
+ bres->ctx = ctx;
+ bres->cb.func = (MemoryContextCallbackFunction) PQclear;
+ bres->cb.arg = res;
+ MemoryContextRegisterResetCallback(ctx, &bres->cb);
+ return bres;
+}
+
+/*
+ * Free a wrapped PGresult, after detaching it from the memory context.
+ * Like PQclear(), allow the argument to be NULL.
+ */
+static inline void
+libpqsrv_PQclear(libpqsrv_PGresult *bres)
+{
+ if (bres)
+ {
+ MemoryContextUnregisterResetCallback(bres->ctx, &bres->cb);
+ PQclear(bres->res);
+ pfree(bres);
+ }
+}
+
+/*
+ * Move a wrapped PGresult to have a different parent context.
+ */
+static inline libpqsrv_PGresult *
+libpqsrv_PGresultSetParent(libpqsrv_PGresult *bres, MemoryContext ctx)
+{
+ libpqsrv_PGresult *newres;
+
+ /* We pass through a NULL result as-is */
+ if (bres == NULL)
+ return NULL;
+ /* Make a new wrapper in the target context, raising error on OOM */
+ newres = (libpqsrv_PGresult *)
+ MemoryContextAlloc(ctx, sizeof(libpqsrv_PGresult));
+ /* Okay, set up the new wrapper */
+ newres->res = bres->res;
+ newres->ctx = ctx;
+ newres->cb.func = (MemoryContextCallbackFunction) PQclear;
+ newres->cb.arg = bres->res;
+ MemoryContextRegisterResetCallback(ctx, &newres->cb);
+ /* Disarm and delete the old wrapper */
+ MemoryContextUnregisterResetCallback(bres->ctx, &bres->cb);
+ pfree(bres);
+ return newres;
+}
+
+/*
+ * Convenience wrapper for PQgetResult.
+ *
+ * We could supply wrappers for other PGresult-returning functions too,
+ * but at present there's no need.
+ */
+static inline libpqsrv_PGresult *
+libpqsrv_PQgetResult(PGconn *conn)
+{
+ return libpqsrv_PQwrap(PQgetResult(conn));
+}
+
+/*
+ * Accessor functions for libpqsrv_PGresult. While it's not necessary to use
+ * these, they emulate the behavior of the underlying libpq functions when
+ * passed a NULL pointer. This is particularly important for PQresultStatus,
+ * which is often the first check on a result.
+ */
+
+static inline ExecStatusType
+libpqsrv_PQresultStatus(const libpqsrv_PGresult *res)
+{
+ if (!res)
+ return PGRES_FATAL_ERROR;
+ return PQresultStatus(res->res);
+}
+
+static inline const char *
+libpqsrv_PQresultErrorMessage(const libpqsrv_PGresult *res)
+{
+ if (!res)
+ return "";
+ return PQresultErrorMessage(res->res);
+}
+
+static inline char *
+libpqsrv_PQresultErrorField(const libpqsrv_PGresult *res, int fieldcode)
+{
+ if (!res)
+ return NULL;
+ return PQresultErrorField(res->res, fieldcode);
+}
+
+static inline char *
+libpqsrv_PQcmdStatus(const libpqsrv_PGresult *res)
+{
+ if (!res)
+ return NULL;
+ return PQcmdStatus(res->res);
+}
+
+static inline int
+libpqsrv_PQntuples(const libpqsrv_PGresult *res)
+{
+ if (!res)
+ return 0;
+ return PQntuples(res->res);
+}
+
+static inline int
+libpqsrv_PQnfields(const libpqsrv_PGresult *res)
+{
+ if (!res)
+ return 0;
+ return PQnfields(res->res);
+}
+
+static inline char *
+libpqsrv_PQgetvalue(const libpqsrv_PGresult *res, int tup_num, int field_num)
+{
+ if (!res)
+ return NULL;
+ return PQgetvalue(res->res, tup_num, field_num);
+}
+
+static inline int
+libpqsrv_PQgetlength(const libpqsrv_PGresult *res, int tup_num, int field_num)
+{
+ if (!res)
+ return 0;
+ return PQgetlength(res->res, tup_num, field_num);
+}
+
+static inline int
+libpqsrv_PQgetisnull(const libpqsrv_PGresult *res, int tup_num, int field_num)
+{
+ if (!res)
+ return 1; /* pretend it is null */
+ return PQgetisnull(res->res, tup_num, field_num);
+}
+
+static inline char *
+libpqsrv_PQfname(const libpqsrv_PGresult *res, int field_num)
+{
+ if (!res)
+ return NULL;
+ return PQfname(res->res, field_num);
+}
+
+static inline const char *
+libpqsrv_PQcmdTuples(const libpqsrv_PGresult *res)
+{
+ if (!res)
+ return "";
+ return PQcmdTuples(res->res);
+}
+
+/*
+ * Redefine these libpq entry point names concerned with PGresults so that
+ * they will operate on libpqsrv_PGresults instead. This avoids needing to
+ * convert a lot of pre-existing code, and reduces the notational differences
+ * between frontend and backend libpq-using code.
+ */
+#define PGresult libpqsrv_PGresult
+#define PQclear libpqsrv_PQclear
+#define PQgetResult libpqsrv_PQgetResult
+#define PQresultStatus libpqsrv_PQresultStatus
+#define PQresultErrorMessage libpqsrv_PQresultErrorMessage
+#define PQresultErrorField libpqsrv_PQresultErrorField
+#define PQcmdStatus libpqsrv_PQcmdStatus
+#define PQntuples libpqsrv_PQntuples
+#define PQnfields libpqsrv_PQnfields
+#define PQgetvalue libpqsrv_PQgetvalue
+#define PQgetlength libpqsrv_PQgetlength
+#define PQgetisnull libpqsrv_PQgetisnull
+#define PQfname libpqsrv_PQfname
+#define PQcmdTuples libpqsrv_PQcmdTuples
+
+#endif /* LIBPQ_BE_FE_H */
diff --git a/src/include/utils/palloc.h b/src/include/utils/palloc.h
index e1b42267b22..039b9cba61a 100644
--- a/src/include/utils/palloc.h
+++ b/src/include/utils/palloc.h
@@ -133,6 +133,8 @@ MemoryContextSwitchTo(MemoryContext context)
/* Registration of memory context reset/delete callbacks */
extern void MemoryContextRegisterResetCallback(MemoryContext context,
MemoryContextCallback *cb);
+extern void MemoryContextUnregisterResetCallback(MemoryContext context,
+ MemoryContextCallback *cb);
/*
* These are like standard strdup() except the copied string is
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 4353befab99..3daba26b237 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3757,6 +3757,7 @@ leafSegmentInfo
leaf_item
libpq_gettext_func
libpq_source
+libpqsrv_PGresult
line_t
lineno_t
list_sort_comparator
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-27 12:50:31 +0000