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From: jordan@morgan.COM (Jordan Hayes)
Newsgroups: comp.windows.x
Subject: Re: Shared Libraries and Patches
Message-ID: <9010032032.AA24339@Morgan.COM>
Date: 3 Oct 90 20:32:22 GMT
References: <9010021331.AA22861@expire.lcs.mit.edu>
Sender: root@athena.mit.edu (Wizard A. Root)
Organization: Morgan Stanley, & Co., Inc. / New York City, NY
Lines: 145


	> I'd like to see the Sun shared library support go into sun.cf,

	I don't know what this means.

I'd like SharedLibraryObjectRule() to be defined in sun.cf, and for
Imake.rules to say something like

#ifndef	SharedLibraryObjectRule
#define	SharedLibraryObjectRule()
#endif

Then for the different types of shared libraries out there, you'd need
to define a rule for SharedLibraryObjectRule in your .cf file ... Like,
how have people hacked in shared library support for SYS V.2 machines,
like the Intergraph that was mentioned recently or (more to my neck of
the woods), A/UX 2.0?

Seems kind of weird for HasSunOSSharedLibraries to appear in a bunch of
random files.  I thought the achitecture-independent portion of the
rules should be in the <vendor>.cf file?

	Perhaps you'd like to make such changes locally and try them
	for a few months (gratuitously installing new versions from
	time to time) to see if it really works?

I have been, actually, for Motif 1.0 (and more recently 1.1), and i've
found that the biggest change is to the *LibraryObjectRule() stuff.
Are there any other machines (other than AIX -- grrr) where "cc -o"
doesn't work?  Near as I can tell, that's a v7-ism (where's Henry when
you need him?), and it seems like a reasonable thing to expect.
Without this support, you need to do that

	$(CC) ...
	$(MV) $@ shared/$@

hack.  What this really means is that if you have libraries built and
you decide to add one of {shared,debugged,profiled} to your
Project.tmpl, you have to rebuild everything -- actually, you have to
do a "make clean" before you re-make, because there's no target for

shared/%.o:

anywhere.

For instance, here's my ProfiledLibraryObject and ProfiledLibraryTarget

----- cut here

#ifndef	NewProfiledLibraryObjectRule
#define	NewProfiledLibraryObjectRule()					@@\
all::									@@\
	-@if [ ! -d profiled ]; then mkdir profiled; else exit 0; fi	@@\
									@@\
profiled/%.o:	%.c							@@\
	$(RM) $@							@@\
	$(CC) -pg -o $@ -c $(CFLAGS) $<					@@\
									@@\
clean::									@@\
	-@if [ -d profiled ]; then echo "	$(RM) profiled/?*.o"; \	@@\
		$(RM) profiled/?*.o; else exit 0; fi			@@\

#endif	/* NewProfiledLibraryObjectRule */

/*
 * NewProfiledLibraryTarget - generate rules to create a profiled library.
 */
#ifndef NewProfiledLibraryTarget
#define	NewProfiledLibraryTarget(libname,objlist)			@@\
AllTarget(lib/**/libname/**/_p.a)					@@\
									@@\
Profiled/**/libname/**/Objs = $(objlist:%=profiled/%)			@@\
									@@\
lib/**/libname/**/_p.a: $(Profiled/**/libname/**/Objs)			@@\
	$(RM) $@							@@\
	cd profiled; $(AR) ../$@ $(objlist)				@@\
	$(RANLIB) $@							@@\
									@@\
clean::									@@\
	$(RM) lib/**/libname/**/_p.a

#endif /* NewProfiledLibraryTarget */

----- cut here

Given the following Imakefile,

----- cut here

SRCS	= foo.c bar.c mumble.c
OBJS	= $(SRCS:%.c=%.o)

NewProfiledLibraryObjectRule()
NewProfiledLibraryTarget(libXm,OBJS)

----- cut here

gives you (approximately)

----- cut here

all::
	-@if [ ! -d profiled ]; then mkdir profiled; else exit 0; fi

profiled/%.o: %.c
	$(RM) $@
	$(CC) -pg -o $@ -c $(CFLAGS) $<

clean::
	-@if [ -d profiled ]; then echo "	$(RM) profiled/?*.o"; \
	$(RM) profiled/?*.o; else exit 0; fi

all:: libXm_p.a

ProfiledXmObjs = $(OBJS:%=profiled/%)

libXm_p.a: $(ProfiledXmObjs)
	$(RM) $@
	cd profiled; $(AR) ../$@ $(OBJS)
	$(RANLIB) $@

clean::
	$(RM) libXm_p.a

----- cut here

As for minor version numbers, we have the Motif shared libraries using
the following system:

	libXm.so.${OSFMajor}.${OSFMinor}${OSFMinor2}${LocalLevel}

e.g., the first shot from OSF Motif 1.1 becomes

	libXm.so.1.100

so I have 10 shots at bug-fixes locally before 1.1.1 comes out (which
would become libXm.so.110).  Since we have production code here running
with these shared libraries, you can't just "make install" over the old
libraries, so we bump ${LocalLevel} and 3-5 days later remove the
${LocalLevel} - 1 version ... this way new instances of programs get
the new library, and old ones just die off eventually.

There's more, of course, but I'd better take it off line ...

/jordan