meson: add instructions for adding new arch to syscall.h

src/include/override/sys/generate-syscall.py

@@ -39,6 +39,9 @@ HEADER = '''\
  *
  * Use 'ninja -C build update-syscall-tables' to download new syscall tables,
  * and 'ninja -C build update-syscall-header' to regenerate this file.
+ *
+ * To add a new architecture, extend the arch_list list in meson.build
+ * and the template in generate-syscall.py and then run the above commands.
  */
 #pragma once
 

src/include/override/sys/meson.build

@@ -31,7 +31,9 @@ syscall_list_txt = files('syscall-list.txt')
 
 syscall_lists = []
 foreach arch: arch_list
-        syscall_lists += files('syscalls-@0@.txt'.format(arch))
+        # We don't use files() here so that the 'update-syscall-tables' call
+        # above can run if arch_list is extended.
+        syscall_lists += meson.current_source_dir() / 'syscalls-@0@.txt'.format(arch)
 endforeach
 
 generate_syscall_py = find_program('generate-syscall.py')

src/include/override/sys/syscall.h

@@ -3,6 +3,9 @@
  *
  * Use 'ninja -C build update-syscall-tables' to download new syscall tables,
  * and 'ninja -C build update-syscall-header' to regenerate this file.
+ *
+ * To add a new architecture, extend the arch_list list in meson.build
+ * and the template in generate-syscall.py and then run the above commands.
  */
 #pragma once