Re: Building shared library for lzlib

Hi,

Thanks for the reply. I should have included the output of the make without the change, it is unable to build the unmodified distribution, as you can see here:

Actually I found another couple of issues when going back and getting the output, which I missed, but it doesn’t seem to affect the install.

(base) [unixwzrd@xanax: lzlib-1.14]$ make -v

GNU Make 4.4.1

Built for aarch64-apple-darwin24.0.0

License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>

This is free software: you are free to change and redistribute it.

There is NO WARRANTY, to the extent permitted by law.

(base) [unixwzrd@xanax: lzlib-1.14]$ ./configure --enable-shared

creating config.status

creating Makefile

VPATH = .

prefix = /usr/local

exec_prefix = $(prefix)

bindir = $(exec_prefix)/bin

datarootdir = $(prefix)/share

includedir = $(prefix)/include

infodir = $(datarootdir)/info

libdir = $(exec_prefix)/lib

mandir = $(datarootdir)/man

CC = gcc

AR = ar

CPPFLAGS =

CFLAGS = -Wall -W -O2

LDFLAGS =

ARFLAGS = -rcs

MAKEINFO = makeinfo

OK. Now you can run make.

(base) [unixwzrd@xanax: lzlib-1.14]$ make

gcc -Wall -W -O2 -c -o carg_parser.o carg_parser.c

gcc -Wall -W -O2 -DPROGVERSION=\"1.14\" -c -o minilzip.o minilzip.c

gcc -Wall -W -O2 -c -o lzlib.o lzlib.c

ar -rcs liblz.a lzlib.o

gcc -Wall -W -O2 -o minilzip carg_parser.o minilzip.o liblz.a

gcc -Wall -W -O2 -fpic -fPIC -c -o lzlib_sh.o lzlib.c

gcc -Wall -W -O2 -fpic -fPIC -shared -Wl,--soname=liblz.so.1 -o liblz.so.1.14 lzlib_sh.o

ld: unknown options: --soname=liblz.so.1

collect2: error: ld returned 1 exit status

make: *** [Makefile:61: liblz.so.1.14] Error 1

This fails because the linker is looking for the library, “—soname=liblz.so.1” which does not exist. Also this linker argument is to link with that library.

Here it is with the —soname removed, but the soversion in the Makefile is set to 1, and that can’t be found either. The linker cannot find "libel.so.1"

(base) [unixwzrd@xanax: lzlib-1.14]$ make

gcc -Wall -W -O2 -c -o carg_parser.o carg_parser.c

gcc -Wall -W -O2 -DPROGVERSION=\"1.14\" -c -o minilzip.o minilzip.c

gcc -Wall -W -O2 -c -o lzlib.o lzlib.c

ar -rcs liblz.a lzlib.o

gcc -Wall -W -O2 -o minilzip carg_parser.o minilzip.o liblz.a

gcc -Wall -W -O2 -fpic -fPIC -c -o lzlib_sh.o lzlib.c

gcc -Wall -W -O2 -fpic -fPIC -shared -Wl,liblz.so.1 -o liblz.so.1.14 lzlib_sh.o

ld: file cannot be open()ed, errno=2 path=liblz.so.1 in 'liblz.so.1'

collect2: error: ld returned 1 exit status

make: *** [Makefile:61: liblz.so.1.14] Error 1

Here is the output with my patch, the linker doesn’t need a stared object to link with to create the shared object. I also found a few other things which were inconsistent when looking deeper t reproducing the issue. Seems there was a lot of issues and confusion over pkgversion and soversion, also the dependency Here’s the clean compile:

(base) [unixwzrd@xanax: lzlib-1.14]$ make -v

GNU Make 4.4.1

Built for aarch64-apple-darwin24.0.0

License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>

This is free software: you are free to change and redistribute it.

There is NO WARRANTY, to the extent permitted by law.

(base) [unixwzrd@xanax: lzlib-1.14]$ ./configure --enable-shared

creating config.status

creating Makefile

VPATH = .

prefix = /usr/local

exec_prefix = $(prefix)

bindir = $(exec_prefix)/bin

datarootdir = $(prefix)/share

includedir = $(prefix)/include

infodir = $(datarootdir)/info

libdir = $(exec_prefix)/lib

mandir = $(datarootdir)/man

CC = gcc

AR = ar

CPPFLAGS =

CFLAGS = -Wall -W -O2

LDFLAGS =

ARFLAGS = -rcs

MAKEINFO = makeinfo

OK. Now you can run make.

(base) [unixwzrd@xanax: lzlib-1.14]$ make

gcc -Wall -W -O2 -c -o carg_parser.o carg_parser.c

gcc -Wall -W -O2 -DPROGVERSION=\"1.14\" -c -o minilzip.o minilzip.c

gcc -Wall -W -O2 -c -o lzlib.o lzlib.c

ar -rcs liblz.a lzlib.o

gcc -Wall -W -O2 -o minilzip carg_parser.o minilzip.o liblz.a

gcc -Wall -W -O2 -fpic -fPIC -shared -o liblz.so.1.14 lzlib.o

gcc -Wall -W -O2 -o minilzip_shared carg_parser.o minilzip.o liblz.so.1.14

(base) [unixwzrd@xanax: lzlib-1.14]$ diff Makefile.in Makefile.dist.in

28,29c28,29

< lib$(libname).so.$(soversion) : lzlib.o

< $(CC) $(CFLAGS) $(LDFLAGS) -fpic -fPIC -shared -o $@ $<

---

> lib$(libname).so.$(pkgversion) : lzlib_sh.o

> $(CC) $(CFLAGS) $(LDFLAGS) -fpic -fPIC -shared -Wl,--soname=lib$(libname).so.$(soversion) -o $@ $<

34,35c34,35

< $(progname)_shared : $(objs) lib$(libname).so.$(soversion)

< $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(objs) lib$(libname).so.$(soversion)

---

> $(progname)_shared : $(objs) lib$(libname).so.$(pkgversion)

> $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(objs) lib$(libname).so.$(pkgversion)

47a48,50

> lzlib_sh.o : lzlib.c

> $(CC) $(CPPFLAGS) $(CFLAGS) -fpic -fPIC -c -o $@ $<

(base) [unixwzrd@xanax: lzlib-1.14]$ diff configure configure.dist

10,11c10

< # soversion=1.14

< soversion=${pkgversion}

---

> soversion=1

The -Wl, will instruct the linker to link with that library, you really don’t want the library to try to link with itself, and it won’t work anyway, you will get duplicate symbol errors IIRC, if someone has LD_LIBRARY_PATH, LD_FLAGS, or CFLAGS containing a

-L/usr/local/lib

in them. I encountered this issue when trying to compile and link a new version of libiconv with the new macOS Sequoia libraries, I believe it was which kept insisting it link with itself in /usr/local/lib. In any event, the lines in your makefile,

lib$(libname).so.$(soversion) : lzlib.o

$(CC) $(CFLAGS) $(LDFLAGS) -fpic -fPIC -shared -o $@ $<

Will work correctly as shown in the compile above and should work on any other OS you try it on. $@ expands to the target lib$(libname).so.$(soversion) and $< will take the dependency, lzlib.o, which is what you want isn’t it?

I also removed the libel_sh.o because it is really unnecessary, once the libel.o file is built, it just needs the link step to either be made static or shared. This should also work on any flavor Linux/Unix system as well.

The mini_lzip also gets built too.

Cheers,

Mike

---
Michael Sullivan

Distributed Thinking Systems LLC
unixwzrd@unixwzrd.ai

LinkedIn: https://www.linkedin.com/in/unixwzrd/

GitHub: https://github.com/unixwzrd

Phone: +1-662-202-7716

On Oct 18, 2024, at 11:30, p.z.l <p.z.l@o2.pl> wrote:

. After looking at it I think that lzlib does not need the --soname mechanism; it

can simply create the shared library as liblz.so.1 instead of liblz.so.1.14.

While I don't have strong opinion on --soname, calling liblz.so.1 instead of liblz.so.1.15 is somewhat surprising and not well understood. Considering that virtually all libraries exactly that naming scheme, or notation, ( like in example: paste.ee/p/xXXxX ).

It (the old scheme) is also useful information in case of testing different/multiple versions of library.

From:	M S
Subject:	Re: Building shared library for lzlib
Date:	Fri, 18 Oct 2024 18:53:08 +0000