quick windows fixes for 4.03

[fdopen]

three windows related changes - feel free to cherry-pick:

My_unix.run_and_open will either call the internal My_unix.run_and_open (

ocamlbuild/src/my_unix.ml

Line 62 in 982fdf1

let run_and_open s kont =

) or Ocamlbuild_unix_plugin.run_and_open (

ocamlbuild/src/ocamlbuild_unix_plugin.ml

Line 50 in 982fdf1

let run_and_open s kont =

).

The first function will use bash, the second plain cmd.exe. That's confusing. You can't always know, which function will be called, but you have to quote differently for both cases (Filename.quote vs Shell.quote_filename_if_needed). It can happen e.g. here:

ocamlbuild/src/ocaml_specific.ml

Line 752 in 982fdf1

let camlp4dir =

2>/dev/null is obviously wrong for cmd.exe, but bash.exe will accept it.

Proper shell quoting. The code is copy&pasted from the ocaml source tree, because it is not exported. (See http://caml.inria.fr/mantis/view.php?id=6287 )

Another side effect of allowing file names that starts with '_'. Hygiene.check now complains frequently about files under '_build/' (eg. myocamlbuild.cmi). The default build dir is: let build_dir = ref (Filename.concat (Sys.getcwd ()) "_build"). Filename.concat always use backslashes as path separator. My_std.filename_concat (/) however uses slashes, therefore the comparison here (

ocamlbuild/src/main.ml

Line 162 in 13feb3c

&& ((* beware: !Options.build_dir is an absolute directory *)

) won't return the desired result. (see ocaml/opam-repository#6224 )

I've just changed Pathname.normalize, that previously didn't work reliable on windows at all, because only slashes were treated as path separators. It now always return a version of the file name with an uppercase drive letter and only forward slashes. (I've first tried to return a string with backslashes, but the solver didn't like it.)

[gasche]

Is there a reason for not calling sys_command directly?

[fdopen]

Why is implem.run_and_open overwritten in the first place?
I've assumed to avoid a temporary file, if Unix.open_process_in is used instead of Sys.command.

[gasche]

I don't know anything about windows programming so I won't be able to review this PR. @whitequark or @dra27, any suggestions?

[gasche]

@fdopen, I would like to make a release for the new 4.03-specific flags, and I am not sure which portions of this PR to include in it. In the end, I would like to include everything, but I haven't had any feedback from other people using ocamlbuild on Windows, so I won't include the more invasive changes right now.

I wrote a smaller patch (pushed in master) trying to fix the detection of the build directory in the hygiene check, b29023c . Could you maybe give it a try and say if it suffices to solve the problem (3) on your machine?

[msprotz]

1. and 2) are good but I would like to see 2) fixed properly, a.k.a. export unix_quote in the standard library; just hide it after (** / **) so that it doesn't appear in the doc if it's controversial

Please be aware that there's a MASSIVE caveat with running bash -c (see http://stackoverflow.com/questions/9946586/cygwin-bash-c-yields-different-argc-depending-on-whether-the-command-start-with) and that this has bitten us in the past (that's the reason why I added '' in front of every command launched by ocamlbuild via its bash-on-windows invocation).

[hhugo]

(1) was included in #329
(2) is part of #333
(3) probably no longer needed now that we have b29023c