Suppress some compiler warnings in recent commits.

Older versions of gcc tend to throw "variable might be clobbered by
`longjmp' or `vfork'" warnings whenever a variable is assigned in more than
one place and then used after the end of a PG_TRY block.  That's reasonably
easy to work around in execute_extension_script, and the overhead of
unconditionally saving/restoring the GUC variables seems unlikely to be a
serious concern.

Also clean up logic in ATExecValidateConstraint to make it easier to read
and less likely to provoke "variable might be used uninitialized in this
function" warnings.

diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 50032031976d8a2d2086f57620caf25afb79b100..ee42d2e13df63c2c16f547ead33b689c31bbc0c3 100644 (file)
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -521,8 +521,8 @@ execute_extension_script(Oid extensionOid, ExtensionControlFile *control,
                                                 const char *schemaName, Oid schemaOid)
 {
        char       *filename = get_extension_absolute_path(control->script);
-       char       *save_client_min_messages = NULL,
-                          *save_log_min_messages = NULL,
+       char       *save_client_min_messages,
+                          *save_log_min_messages,
                           *save_search_path;
        StringInfoData pathbuf;
        ListCell   *lc;
@@ -535,23 +535,19 @@ execute_extension_script(Oid extensionOid, ExtensionControlFile *control,
         * We use the equivalent of SET LOCAL to ensure the setting is undone
         * upon error.
         */
+       save_client_min_messages =
+               pstrdup(GetConfigOption("client_min_messages", false));
        if (client_min_messages < WARNING)
-       {
-               save_client_min_messages =
-                       pstrdup(GetConfigOption("client_min_messages", false));
                (void) set_config_option("client_min_messages", "warning",
                                                                 PGC_USERSET, PGC_S_SESSION,
                                                                 GUC_ACTION_LOCAL, true);
-       }
 
+       save_log_min_messages =
+               pstrdup(GetConfigOption("log_min_messages", false));
        if (log_min_messages < WARNING)
-       {
-               save_log_min_messages =
-                       pstrdup(GetConfigOption("log_min_messages", false));
                (void) set_config_option("log_min_messages", "warning",
                                                                 PGC_SUSET, PGC_S_SESSION,
                                                                 GUC_ACTION_LOCAL, true);
-       }
 
        /*
         * Set up the search path to contain the target schema, then the schemas
@@ -631,15 +627,12 @@ execute_extension_script(Oid extensionOid, ExtensionControlFile *control,
        (void) set_config_option("search_path", save_search_path,
                                                         PGC_USERSET, PGC_S_SESSION,
                                                         GUC_ACTION_LOCAL, true);
-
-       if (save_client_min_messages != NULL)
-               (void) set_config_option("client_min_messages", save_client_min_messages,
-                                                                PGC_USERSET, PGC_S_SESSION,
-                                                                GUC_ACTION_LOCAL, true);
-       if (save_log_min_messages != NULL)
-               (void) set_config_option("log_min_messages", save_log_min_messages,
-                                                                PGC_SUSET, PGC_S_SESSION,
-                                                                GUC_ACTION_LOCAL, true);
+       (void) set_config_option("client_min_messages", save_client_min_messages,
+                                                        PGC_USERSET, PGC_S_SESSION,
+                                                        GUC_ACTION_LOCAL, true);
+       (void) set_config_option("log_min_messages", save_log_min_messages,
+                                                        PGC_SUSET, PGC_S_SESSION,
+                                                        GUC_ACTION_LOCAL, true);
 }
 
 /*

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f67e9b9b16290f496f8d4343cbfd6a0f19c5f544..9c812397b1e5fa3614a11fb95f535bf014aaf9df 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -5612,17 +5612,16 @@ static void
 ATExecValidateConstraint(Relation rel, const char *constrName)
 {
        Relation        conrel;
-       Form_pg_constraint con;
        SysScanDesc scan;
        ScanKeyData key;
        HeapTuple       tuple;
+       Form_pg_constraint con = NULL;
        bool            found = false;
-       Oid                     conid;
 
        conrel = heap_open(ConstraintRelationId, RowExclusiveLock);
 
        /*
-        * Find and the target constraint
+        * Find and check the target constraint
         */
        ScanKeyInit(&key,
                                Anum_pg_constraint_conrelid,
@@ -5634,17 +5633,23 @@ ATExecValidateConstraint(Relation rel, const char *constrName)
        while (HeapTupleIsValid(tuple = systable_getnext(scan)))
        {
                con = (Form_pg_constraint) GETSTRUCT(tuple);
-
-               if (strcmp(NameStr(con->conname), constrName) != 0)
-                       continue;
-
-               conid = HeapTupleGetOid(tuple);
-               found = true;
-               break;
+               if (con->contype == CONSTRAINT_FOREIGN &&
+                       strcmp(NameStr(con->conname), constrName) == 0)
+               {
+                       found = true;
+                       break;
+               }
        }
 
-       if (found && con->contype == CONSTRAINT_FOREIGN && !con->convalidated)
+       if (!found)
+               ereport(ERROR,
+                               (errcode(ERRCODE_UNDEFINED_OBJECT),
+                       errmsg("foreign key constraint \"%s\" of relation \"%s\" does not exist",
+                                  constrName, RelationGetRelationName(rel))));
+
+       if (!con->convalidated)
        {
+               Oid                     conid = HeapTupleGetOid(tuple);
                HeapTuple       copyTuple = heap_copytuple(tuple);
                Form_pg_constraint copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
                Relation        refrel;
@@ -5671,19 +5676,13 @@ ATExecValidateConstraint(Relation rel, const char *constrName)
                simple_heap_update(conrel, &copyTuple->t_self, copyTuple);
                CatalogUpdateIndexes(conrel, copyTuple);
                heap_freetuple(copyTuple);
+
                heap_close(refrel, NoLock);
        }
 
        systable_endscan(scan);
-       heap_close(conrel, RowExclusiveLock);
 
-       if (!found)
-       {
-               ereport(ERROR,
-                               (errcode(ERRCODE_UNDEFINED_OBJECT),
-                       errmsg("foreign key constraint \"%s\" of relation \"%s\" does not exist",
-                                  constrName, RelationGetRelationName(rel))));
-       }
+       heap_close(conrel, RowExclusiveLock);
 }
 
 /*