RFR(S): 8022177: Windows/MSYS builds broken

[Volker Simonis]

Hi,

could somebody please review these straightforward changes which fix
the MinGW7MSYS build on Windows:

http://cr.openjdk.java.net/~simonis/webrevs/8022177/
https://bugs.openjdk.java.net/browse/JDK-8022177

The details of the change can be found below and in the webrev. I
think I need a sponsor for this change because it requires the
re-generation of generated-configure files (closed and open).

I also want to mention that we at SAP are using the MinGW/MSYS build
on Windows since more than a year for all our Java builds (from 4 to
8) on Windows and we're highly committed in keeping this build
environment alive.

Independently from this change I also have a general question related
to the MSYS build:
During an MSYS build the Windows command shell is usually called like this:

`cmd //c echo $unix_path`

As far as I understand, the double slash is needed to prevent MSYS
from rewriting '/c' to 'c:/' when calling a non-MSYS executable. But
sometimes (notably in BASIC_MAKE_WINDOWS_SPACE_SAFE_MSYS in
basic_windows.m4) we call the Windows command shell without a quoted
forward slash like this:

new_path=`cmd /c "for %A in (\"$input_path\") do @echo %~sA"

and I don't understand why this works.

To complicate things, the MSYS environment contains its own 'cmd'
shell script in '/usr/bin/cmd' which only redirects to the
corresponding Windows command shell like so:

#!/bin/sh
"$COMSPEC" "$@"

Unfortunately I didn't succeed in unifying all the calls to 'cmd' to a
single pattern (i.e. either `cmd //c ...`, or `/usr/bin/cmd /c ...`)
which would be desirable, because depending on the actual PATH
settings, `cmd` may either call "/usr/bin/cmd" or
"C:\Windows\System32\cmd.exe".

Can anybody shed some light on this topic (i.e. which "cmd" we want to
call and why we have to quote "/c" differently)?

Thank you and best regards,
Volker



1. common/autoconf/basics.m4

- Check for bsdcpio if cpio is not found. Also make the check for cpio
optional, as suggested in the bug report.
- Only do the BASIC_CHECK_SRC_PERMS check on Cygwin as it only seems
to be relavant there and because the stat utility isn't availabel in
MSYS anyway.

2. common/autoconf/basics_windows.m4

- Same story like on Cygwin: '.bat' and '.cmd' files are not always
considered executable in MSYS causing which to not find them.

3. common/autoconf/flags.m4

- Use "-WX" option syntax for cl options (instead of "/WX") to prevent
option rewriting by MSYS.

4. toolchain_windows.m4

- Account for the fact that the MSYS file utility reports different
file types for Windows DLLs than its Cygwin counterpart.