add PG function declerations that are not generated by pgrx yet

src/lib.rs

@@ -1,5 +1,6 @@
 use pgrx::prelude::*;
 
+mod pgrx_missing_declerations;
 mod pgrx_utils;
 
 pgrx::pg_module_magic!();

src/pgrx_missing_declerations.rs

@@ -0,0 +1,54 @@
+use pgrx::{
+    pg_sys::{self, Alias, Oid, ParseNamespaceItem, ParseState, Relation, TupleTableSlot},
+    PgBox,
+    prelude::*,
+};
+
+#[allow(improper_ctypes)]
+#[pg_guard]
+extern "C" {
+    pub(crate) fn get_extension_oid(name: *const i8, missing_ok: bool) -> Oid;
+
+    pub(crate) fn get_extension_schema(ext_oid: Oid) -> Oid;
+
+    pub(crate) fn addRangeTableEntryForRelation(
+        pstate: *mut ParseState,
+        rel: Relation,
+        lockmode: i32,
+        alias: *mut Alias,
+        inh: bool,
+        inFromCl: bool,
+    ) -> *mut ParseNamespaceItem;
+
+    pub(crate) fn addNSItemToQuery(
+        pstate: *mut ParseState,
+        nsitem: *mut ParseNamespaceItem,
+        add_to_join_list: bool,
+        add_to_rel_namespace: bool,
+        add_to_var_namespace: bool,
+    );
+
+    pub(crate) fn assign_expr_collations(
+        pstate: *mut ParseState,
+        expr: *mut pg_sys::Node,
+    ) -> *mut pg_sys::Node;
+}
+
+/*
+ * slot_getallattrs
+ *		This function forces all the entries of the slot's Datum/isnull
+ *		arrays to be valid.  The caller may then extract data directly
+ *		from those arrays instead of using slot_getattr.
+ */
+pub(crate) fn slot_getallattrs(slot: *mut TupleTableSlot) {
+    // copied from Postgres since this method was inlined in the original code
+    // (not found in pg_sys)
+    // handles select * from table
+    unsafe {
+        let slot = PgBox::from_pg(slot);
+        let tts_tupledesc = PgBox::from_pg(slot.tts_tupleDescriptor);
+        if (slot.tts_nvalid as i32) < tts_tupledesc.natts {
+            pg_sys::slot_getsomeattrs_int(slot.as_ptr(), tts_tupledesc.natts);
+        }
+    };
+}