If you notice that this procedure fails for a given change you are trying to implement, please report it so that the procedure can be updated to also cope with your change.

If you want to upstream your changes, indicate in the message of the commit that the changes need a bootstrap. Perform the bootstrap and commit the result of the bootstrap separately, after that commit.

Primitives can be added without having to bootstrap, however it is necessary to repeat make coldstart in order to use your new primitive in the standard library.

There are five steps to renaming a primitive:

1. Rename the primitive and its uses

2. Create a temporary stub with the old primitive’s name. This stub simply passes its arguments on to the new primitive:

   CAMLprim value caml_old_primitive(value a1, value a2) {
     return caml_new_primitive(a1, a2);
   }

3. Deal with the addition of the new primitive:

   make coldstart

4. Ensure the system still works:

   make coreall

5. Now remove the old primitive stub and issue:

   make bootstrap

It is desirable for bootstraps to be easily repeatable, so you should commit changes after step 4.

To remove a primitive:

1. Start with a working build of the compiler eg ./configure && make world

2. Remove uses of the primitive, but not the primitive itself. Then ensure the system still works:

   make coreall

3. Then, and only then, remove the primitive, and run:

   make coreall
   make bootstrap

A script is provided (and used on Inria’s continuous integration infrastructure) to make sure the bootstrap works. This script implements the bootstrap procedure described above and performs two changes to the compiler: it updates the magic numbers and removes a primitive from the runtime. It then makes sure the bootstrap still works after these changes. This script can be run locally as follows: