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 file is meant to be included by the per-directory makefiles
of otherlibs/*/Makefile; its target cannot be run directly from
otherlibs/. We would like to propose targets from otherlibs/,
in a new Makefile.
This commit renames a few C compiler related build variables so that
they are reserved for the build system. They will then be re-introduced,
but this time as user varialbes whose value can be freely customized
when compiling the package, without risking to conflict with those
command-line flags that are required by the build system itself.
Here are the variables this commit renames:
- CFLAGS -> OC_CFLAGS
- CPPFLAGS -> OC_CPPFLAGS
- LDFLAGS -> OC_LDFLAGS
Note: before this commit the compilation of scheduler.c in
otherlibs/threads was relying on make's implicit rule to compile C files.
Since this commit stops using the standard variables for flags,
it is necessary to introduce an explicit rule to compile C files
and that makes use of the newly introduced variables.
The code in this commit was written by Marcell Fischbach & Benedikt Meurer.
See [Mantis#5324](http://caml.inria.fr/mantis/view.php?id=5324) for some
context.
The code (which was originally written against 3.12) was ported to trunk by
doing
```bash
git clone https://github.com/bmeurer/ocaml-experimental/
cd ocaml-experimental
git diff master...linear-scan-register-allocator > t.diff
```
and then applying the diff by hand.
David Allsopp
Sébastien Hinderer
Gabriel Scherer
Nicolás Ojeda Bär
Damien Doligez
Mark Shinwell