Core support for "extensions", which are packages of SQL objects.

This patch adds the server infrastructure to support extensions.
There is still one significant loose end, namely how to make it play nice
with pg_upgrade, so I am not yet committing the changes that would make
all the contrib modules depend on this feature.

In passing, fix a disturbingly large amount of breakage in
AlterObjectNamespace() and callers.

Dimitri Fontaine, reviewed by Anssi Kääriäinen,
Itagaki Takahiro, Tom Lane, and numerous others

1 files changed, 27 insertions, 15 deletions

diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index dad65ee8ffa..3f25b3bf02a 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -1762,6 +1762,9 @@ CreateCast(CreateCastStmt *stmt)
 		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 	}
 
+	/* dependency on extension */
+	recordDependencyOnCurrentExtension(&myself);
+
 	/* Post creation hook for new cast */
 	InvokeObjectAccessHook(OAT_POST_CREATE,
 						   CastRelationId, myself.objectId, 0);
@@ -1875,13 +1878,7 @@ AlterFunctionNamespace(List *name, List *argtypes, bool isagg,
 					   const char *newschema)
 {
 	Oid			procOid;
-	Oid			oldNspOid;
 	Oid			nspOid;
-	HeapTuple	tup;
-	Relation	procRel;
-	Form_pg_proc proc;
-
-	procRel = heap_open(ProcedureRelationId, RowExclusiveLock);
 
 	/* get function OID */
 	if (isagg)
@@ -1889,20 +1886,33 @@ AlterFunctionNamespace(List *name, List *argtypes, bool isagg,
 	else
 		procOid = LookupFuncNameTypeNames(name, argtypes, false);
 
-	/* check permissions on function */
-	if (!pg_proc_ownercheck(procOid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
-					   NameListToString(name));
+	/* get schema OID and check its permissions */
+	nspOid = LookupCreationNamespace(newschema);
+
+	AlterFunctionNamespace_oid(procOid, nspOid);
+}
+
+Oid
+AlterFunctionNamespace_oid(Oid procOid, Oid nspOid)
+{
+	Oid			oldNspOid;
+	HeapTuple	tup;
+	Relation	procRel;
+	Form_pg_proc proc;
+
+	procRel = heap_open(ProcedureRelationId, RowExclusiveLock);
 
 	tup = SearchSysCacheCopy1(PROCOID, ObjectIdGetDatum(procOid));
 	if (!HeapTupleIsValid(tup))
 		elog(ERROR, "cache lookup failed for function %u", procOid);
 	proc = (Form_pg_proc) GETSTRUCT(tup);
 
-	oldNspOid = proc->pronamespace;
+	/* check permissions on function */
+	if (!pg_proc_ownercheck(procOid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
+					   NameStr(proc->proname));
 
-	/* get schema OID and check its permissions */
-	nspOid = LookupCreationNamespace(newschema);
+	oldNspOid = proc->pronamespace;
 
 	/* common checks on switching namespaces */
 	CheckSetNamespace(oldNspOid, nspOid, ProcedureRelationId, procOid);
@@ -1916,7 +1926,7 @@ AlterFunctionNamespace(List *name, List *argtypes, bool isagg,
 				(errcode(ERRCODE_DUPLICATE_FUNCTION),
 				 errmsg("function \"%s\" already exists in schema \"%s\"",
 						NameStr(proc->proname),
-						newschema)));
+						get_namespace_name(nspOid))));
 
 	/* OK, modify the pg_proc row */
 
@@ -1930,11 +1940,13 @@ AlterFunctionNamespace(List *name, List *argtypes, bool isagg,
 	if (changeDependencyFor(ProcedureRelationId, procOid,
 							NamespaceRelationId, oldNspOid, nspOid) != 1)
 		elog(ERROR, "failed to change schema dependency for function \"%s\"",
-			 NameListToString(name));
+			 NameStr(proc->proname));
 
 	heap_freetuple(tup);
 
 	heap_close(procRel, RowExclusiveLock);
+
+	return oldNspOid;
 }