https://bugs.gentoo.org/874702#c8
--- pmtools-orig/madt/madt.c	2005-11-12 04:07:04.000000000 +1100
+++ pmtools/madt/madt.c	2024-06-06 12:04:59.554214977 +1000
@@ -42,7 +42,7 @@
 /* read standard input
  * write decoded madt to standard output
  */
-get_next_entry(acpi_table_entry_header * entry_header)
+int get_next_entry(acpi_table_entry_header * entry_header)
 {
 	size_t retval;
 
@@ -53,7 +53,7 @@
 
 u8	buffer[1024];
 
-main()
+int main()
 {
 	size_t retval;
 	struct acpi_table_madt *madt_header;