[Zlib-devel] zlib 1.2.4 released

[Nelson H. F. Beebe]

>> So the DEC compiler doesn't any sort of variable argument list capability?

OSF/1 has both old and new style:

    % ls -l /usr/include/*arg*.h
    -r--r--r-- 1 bin bin 2646 Apr 12  1999 /usr/include/args.h
    -r--r--r-- 1 bin bin 2529 Apr 12  1999 /usr/include/stdarg.h
    -r--r--r-- 1 bin bin 2241 Apr 12  1999 /usr/include/varargs.h

I don't spot anything in the build logs that suggest that feature
was tested for:

    % env CC=cc CFLAGS="-ieee -I/usr/local/include" CXX=cxx CXXFLAGS="-ieee -I/usr/local/include" LDFLAGS="-Wl,-rpath,/usr/local/lib -Wl,-oldstyle_liblookup
    -L/usr/local/lib" LIBS="-lsnprintf" FC=f77 F77=f77 ./configure
    Checking for shared library support...
    Building shared library libz.so.1.2.4 with cc.
    Checking for off64_t... No.
    Checking for fseeko... No.
    Checking for unistd.h... Yes.
    Checking whether to use vs[n]printf() or s[n]printf()... using s[n]printf().
    Checking for snprintf() in stdio.h... No.
      WARNING: snprintf() not found, falling back to sprintf(). zlib
      can build but will be open to possible buffer-overflow security
      vulnerabilities.
    Checking for return value of sprintf()... Yes.
    Checking for errno.h... Yes.

Because the configure script is hand-coded, it does not behave like
one from autoconf, leaving behind a config.log file with a detailed
record of its tests.

There is nothing in the newly-created files either:

    % grep ARG zconf.h zlib.pc so_locations
    zconf.h:#ifdef _LARGEFILE64_SOURCE

I then looked at what header files the compiler saw in example.c:

    % cc -ieee -I/usr/local/include -DNO_FSEEKO -DNO_snprintf -E example.c |
	    grep '#.*/usr/include' |
		    awk '{print $3}' |
			    sort -u
    "/usr/include/ctype.h"
    "/usr/include/locale.h"
    "/usr/include/mach/machine/vm_types.h"
    "/usr/include/machine/machlimits.h"
    "/usr/include/machine/machtime.h"
    "/usr/include/standards.h"
    "/usr/include/stdio.h"
    "/usr/include/sys/access.h"
    "/usr/include/sys/lc_core.h"
    "/usr/include/sys/limits.h"
    "/usr/include/sys/localedef.h"
    "/usr/include/sys/rt_limits.h"
    "/usr/include/sys/seek.h"
    "/usr/include/sys/select.h"
    "/usr/include/sys/syslimits.h"
    "/usr/include/sys/types.h"
    "/usr/include/unistd.h"
    "/usr/include/va_list.h"

The only source file with "#include <stdarg.h>" is gzwrite.c (the one
with the failing code on OSF/1 Alpha):

    % cc -ieee -I/usr/local/include -DNO_FSEEKO -DNO_snprintf -E gzwrite.c  | grep '#.*/usr/include' | awk '{print $3}' | sort -u
    "/usr/include/ctype.h"
    "/usr/include/fcntl.h"
    "/usr/include/locale.h"
    "/usr/include/mach/machine/vm_types.h"
    "/usr/include/machine/machlimits.h"
    "/usr/include/machine/machtime.h"
    "/usr/include/standards.h"
    "/usr/include/stdio.h"
    "/usr/include/sys/access.h"
    "/usr/include/sys/fcntl.h"
    "/usr/include/sys/lc_core.h"
    "/usr/include/sys/limits.h"
    "/usr/include/sys/localedef.h"
    "/usr/include/sys/mode.h"
    "/usr/include/sys/rt_limits.h"
    "/usr/include/sys/seek.h"
    "/usr/include/sys/select.h"
    "/usr/include/sys/syslimits.h"
    "/usr/include/sys/types.h"
    "/usr/include/unistd.h"
    "/usr/include/va_list.h"

Notice the absence of a line with stdarg.h.

I then looked at the source file, and see this:

    #ifdef STDC
    #include <stdarg.h>
    ...

The symbol STDC is evidently not defined in a cc compilation.

I then tried a configure and build with CC=c89, and that produced a
successful test:

    % make check
    hello world
    zlib version 1.2.4 = 0x1240, compile flags = 0x20000a9
    uncompress(): hello, hello!
    gzread(): hello, hello!
    gzgets() after gzseek:  hello!
    inflate(): hello, hello!
    large_inflate(): OK
    after inflateSync(): hello, hello!
    inflate with dictionary: hello, hello!
		    *** zlib test OK ***
    hello world
    warning: different zlib version
    zlib version 1.2.4 = 0x1240, compile flags = 0x20000a9
    uncompress(): hello, hello!
    gzread(): hello, hello!
    gzgets() after gzseek:  hello!
    inflate(): hello, hello!
    large_inflate(): OK
    after inflateSync(): hello, hello!
    inflate with dictionary: hello, hello!
		    *** zlib shared test OK ***

So, we have a workaround on this system: use c89 or gcc instead of cc.

I think that the code should have a minor revision to test, possible
with assert(), that sizeof(int) == sizeof(void *), before accepting
the varargs workaround in gzwrite.c.  Alternatively, the configure
script could make a test on the sizes of pointers versus integers.

-------------------------------------------------------------------------------
- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: beebe at math.utah.edu  -
- 155 S 1400 E RM 233                       beebe at acm.org  beebe at computer.org -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe/ -
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