With this commit, it becomes possible to provide C compiler and preprocessor
flags to use in addition to those defined by the build system.
As required by the GNU coding standards, the flags can be provided
either at configure or at make invocation.
The provided CFLAGS and CPPFLAGS will also be taken into account
when C code is compiled by ocamlc/ocamlopt.
This commit removes the explicit reference to CFLAGS in the
configuration for the xlc compiler, since it is not necessary any longer.
This commit touches neither boot/ocamlc nor boot/ocamllex
It has the side-effect of fixing the cleanup rules which did not use the
$(EXE) extension when removing a file although it was produced with the
$(EXE) extension.
Before we would include it if present, but support building without
it. Unless I misunderstand something, this is unnecessarily complex:
- If we want to support building without it, we may as well
do without it all the time (in particular it makes it easier
to spot bugs which occurs when it is missing).
- Certain makefile rules (see config.status) work by being added
as dependencies to Makefile.build_config, and requiring this file
only when actually needed makes it possible to simplify those.
(simplifications not included in this commit)
I reviewed all 'clean' rules to check that they do not depend on
variables defined in the configure. On the other hand, the main
makefiles do a lot of conditional tests on those variables,
so --warn-undefined-variables warns quite a bit. (This could be solved
by a Makefile.no_config rule that mirrors Makefile.config with dummy
definitions.)
The $(wildcard *.h) should only be there with
--disable-dependency-generation, since otherwise gcc -MM will be
determining exactly which header files should be checked.
When building for the first time, the only requirement is that generated
header files have been built (jumptbl.h, version.h and opnames.h).
Detailed dependency information is only required when headers have been
edited.
COMPUTE_DEPS in Makefile.config controls whether C dependency
information should be generated on a per-file basis. This variable is
controlled by a new --disable-dependency-generation in configure which
is enabled for Git checkouts and disabled for tarballs (i.e. releases).
The Microsoft C compiler (cl) cannot generate dependencies in a
consistent way which we can consume, so for a Git checkout configure
searches for an additional C compiler in order to compute dependencies.
This is obviously not required for a user-build.
As a result, the MSVC port can now safely run make alldepend, since only
OCaml dependency information is committed to the repo after this change.
CI does not need to waste time testing the dependency information,
because it only tests a single build. A single Travis job has been added
which tests the build system code to generate the dependency information
(and provides a single `make -j` run in CI, although Inria's CI also
tests parallel building continuously).
This moves the configure-generated parts of Makefile.common to a
separate (generated) Makefile, allowing Makefile.common to be a normal
Makefile.
OCaml's build system Makefile's now include Makefile.build_config (which
itself includes Makefile.config) but Makefile.config is still installed
as before. This allows configure to generate variables which are
specific to the build process and are not intended to be exported to the
installation.
In order to prepare the transition to autoconf, this commit moves the
configuration Makefile out of the config directory which will disappear
and gives it the name it will have once intstalled, namely Makefile.config.
David Allsopp
Sébastien Hinderer
Nicolás Ojeda Bär
Gabriel Scherer