HOWTO

This HOWTO is intended for new Menhir developers, and should explain how
things work.

For the moment, there is not much information in it.

BUILD INSTRUCTIONS
------------------

There are two ways of building Menhir: either from scratch, or incrementally.

Building from scratch is performed via the public Makefile, and requires
defining the PREFIX variable, even if no installation is performed:

  make PREFIX=/usr/local -f Makefile

This is a two-stage process, in which a first version of menhir is built
using ocamlyacc, and a second version of menhir is built using the menhir
executable produced by the first stage.

Building incrementally is useful when working on the code. In that case,
one wishes to recompile incrementally, without going through the bootstrap
process. This works only if a menhir executable already exists in the src/
subdirectory. This is done simply by typing:

  make

(or, equivalently, make -f GNUmakefile).

ABOUT THE MODULE ORDERING
-------------------------
Some toplevel modules have side effects and must be executed in the
following order:

Settings		parses the command line
PreFront		reads the grammar description files
TokenType		deals with --only-tokens and exits
Front			deals with --depend, --infer, --only-preprocess, and exits
Grammar			performs a number of analyses of the grammar
Lr0			constructs the LR(0) automaton
Slr			determines whether the grammar is SLR
Lr1			constructs the LR(1) automaton
Conflict		performs default conflict resolution and explains conflicts
Invariant		performs a number of analyses of the automaton
Interpret		deals with --interpret and exits
Back			produces the output and exits

A few artificial dependencies have been added in the code in order
to ensure that this ordering is respected by ocamlbuild.