CHECK_STRUCTS/dmpstruct.h mechanism is broken.

[Alan Mackenzie]

Hello, Emacs.

The CHECK_STRUCT/dmpstruct.h mechanism is a very clever way of ensuring
that Emacs cannot be built after amending certain structs, or even the
comments within them.

I have amended such a comment, thus cannot build my Emacs.

This mechanism is broken, since it would appear to be entirely
undocumented.  Or does this documentation exist, somewhere obscure?
There is nothing about it in INSTALL.REPO, for example.

For the sake of my sanity, will whoever it is please tell me what I have
now to do to build my Emacs.  make bootstrap fails.  This is a bug; make
bootstrap should _never_ fail.  I've done make dmpstruct.h.  Again to no
avail.

There's a file dmpstruct.awk involved in this, but it contains no
instructions in its header comments; how is it meant to be called for
example?  What else needs to be run to make it work, for another
example?

And what's it all for?  Why should make bootstrap be broken?  What's the
point of all this?  Why are there no explanatory comments in the
generated file dmpstruct.h?

Help!

-- 
Alan Mackenzie (Nuremberg, Germany).