Re: getcwd() issues on VMS / canonicalize-lgpl.c

[Bruno Haible]

Hi John,

> > John Malmberg wrote:
> >> 1. The VMS CRTL getcwd() will not pass configure tests and will be
> >> marked for replacement from gnulib.
> >>
> >> 2. The replacement from gnulib causes canonicalize-lgpl.c to fail
> >> because the replacement only has 2 parameters, not three.
> ...
> I have not encountered the relocatable-prog-wrapper on a VMS project 
> yet, so I do not know what it is.

In the relocatable-prog-wrapper situation, like in all other uses of
gnulib without the 'getcwd' module, getcwd is not #defined. Therefore,
as I understand, it takes 3 arguments.

> It still does not need the vms specific variant as a production program 
> would set the DECCRTL mode to have getcwd() return a Unix format path, 
> usually in a "lib$initialize" object.

gnulib does not make use of per-program initializers. Rather, its overrides
must work in programs as well as in libraries, without additional object
files (other than the ones provided by gnulib).

> For a test program, the same could be done, or the script running the 
> test can define the logical name DECC$FILENAME_UNIX_REPORT "ENABLE" 
> before starting the test.

Programs that use gnulib do not make assumptions about how they are
invoked, or what environments are set when they are run. They must work
out-of-the-box.

To fix the issue you reported, I'm applying this:

2017-06-07  Bruno Haible  <address@hidden>

        canonicalize-lgpl: Avoid conflict with gnulib 'getcwd' module on VMS.
        Reported by John E. Malmberg <address@hidden> in
        <https://lists.gnu.org/archive/html/bug-gnulib/2017-06/msg00029.html>.
        * lib/canonicalize-lgpl.c (__getcwd): On VMS, when using gnulib's getcwd
        override, pass 2 arguments to getcwd, not 3.

diff --git a/lib/canonicalize-lgpl.c b/lib/canonicalize-lgpl.c
index a32da91..34b3711 100644
--- a/lib/canonicalize-lgpl.c
+++ b/lib/canonicalize-lgpl.c
@@ -59,8 +59,10 @@
      */
 #   undef getcwd
 #  endif
-#  ifdef VMS
-    /* We want the directory in Unix syntax, not in VMS syntax.  */
+#  if defined VMS && !defined getcwd
+    /* We want the directory in Unix syntax, not in VMS syntax.
+       The gnulib override of 'getcwd' takes 2 arguments; the original VMS
+       'getcwd' takes 3 arguments.  */
 #   define __getcwd(buf, max) getcwd (buf, max, 0)
 #  else
 #   define __getcwd getcwd


> >> 3. The replacement from gnulib also does not fix all the known ills in
> >> VMS getcwd().

This is something that sounds worthy to look at. As I understand it, the
configure test already marks the getcwd function as to be overridden (because
the incompatible prototype); therefore the fixes should be limited to 
modifications
of lib/getcwd.d and lib/getcwd-lgpl.c.

Bruno