Warn about missing -DMULTIPLICITY if likely a problem

Subject: Re: multiple embedded interpreter example in perlembed.pod fails

Ken Fox <kfox@ford.com> wrote:
> I wrote:
>
> > Multiple embedded interpreters don't work.  Here's a transcript:
> ...
> >     ccflags =''
>
> Ugh.  Stupid user error.  I ran Configure with -DMULTIPLICITY instead
> of -Dccflags='-DMULTIPLICITY'.  Sorry for the confusion.

you can also 'make LIBPERL=libperlm.a', libperld, libperldm, etc., or
edit cflags by hand after Configure.

> Could the
> runtime error message be improved to let people know when they've made
> this mistake?

good idea, something like the patch below?  I'm not sure of other
cases where e_fp would be bogus.

p5p-msgid: 199703192345.SAA15070@postman.osf.org

diff --git a/perl.c b/perl.c
index 06534ff..b3ce9b4 100644 (file)
--- a/perl.c
+++ b/perl.c
@@ -685,8 +685,12 @@ setuid perl scripts securely.\n");
     if (!scriptname)
        scriptname = argv[0];
     if (e_fp) {
-       if (PerlIO_flush(e_fp) || PerlIO_error(e_fp) || PerlIO_close(e_fp))
+       if (PerlIO_flush(e_fp) || PerlIO_error(e_fp) || PerlIO_close(e_fp)) {
+#ifndef MULTIPLICITY
+           warn("Did you forget to compile with -DMULTIPLICITY?");
+#endif     
            croak("Can't write to temp file for -e: %s", Strerror(errno));
+       }
        e_fp = Nullfp;
        argc++,argv--;
        scriptname = e_tmpname;