~ubuntu-branches/ubuntu/precise/apt/precise-updates

General Information

~~~~~~~~~~~~~~~~~~~

To compile this you need a couple things

  - A working POSIX system with working POSIX gcc, g++, make (GNU),

    ar, sh, awk and sed in the path

  - GNU Make 3.74 or so, -- normal UNIX make will NOT work

    * Note 3.77 is broken.    

  - A working ANSI C++ compiler, this is not g++ 2.7.* 

    g++ 2.8 works OK and newer egcs work well also. Nobody has tried it

    on other compilers :< You will need a properly working STL as well.

  - A C library with the usual POSIX functions and a BSD socket layer. 

    If your OS conforms to the Single Unix Spec then you are fine:

      http://www.opengroup.org/onlinepubs/7908799/index.html      

  - Refer to the Build-Depends information in debian/control for

    additional requirements (some of which are Debian-specific)

** NOTICE **

The C++ global constructors do not link correctly when using non-shared

libraries. This is probably the correct behavior of the linker, but I have

not yet had time to devise a work around for it. The correct thing to 

do is add a reference to debSystem in apt-pkg/init.cc, 

assert(&debSystem == 0) would be fine for instance.

Guidelines

~~~~~~~~~~

I am not interested in making 'ultra portable code'. I will accept patches

to make the code that already exists conform more to SUS or POSIX, but

I don't really care if your not-SUS OS doesn't work. It is simply too

much work to maintain patches for dysfunctional OSs. I highly suggest you

contact your vendor and express intrest in a conforming C library.

That said, there are lots of finicky problems that must be dealt with even

between the supported OS's. Primarily the path I choose to take is to put

a shim header file in build/include that transparently adds the required 

functionality. Patches to make autoconf detect these cases and generate the 

required shims are OK.

Current shims:

  * C99 integer types 'inttypes.h' 

  * sys/statvfs.h to convert from BSD/old-glibc statfs to SUS statvfs

  * rfc2553 hostname resolution (methods/rfc*), shims to normal gethostbyname.

    The more adventurous could steal the KAME IPv6 enabled resolvers for those

    OS's with IPv6 support but no rfc2553 (why?)

  * define _XOPEN_EXTENDED_SOURCE to bring in h_errno on HP-UX

  * socklen_t shim in netdb.h if the OS does not have socklen_t

The only completely non-shimmed OS is Linux with glibc2.1, glibc2.0 requires

the first three shims.

Platform Notes

~~~~~~~~~~~~~~

Debian GNU Linux 2.1 'slink'

Debian GNU Linux 'potato'

Debian GNU Linux 'woody'

  * All Archs

  - Works flawlessly

  - You will want to have debiandoc-sgml and docbook2man installed to get

    best results.

  - No IPv6 Support in glibc's < 2.1.

Sun Solaris

  SunOS cab101 5.7 Generic_106541-04 sun4u sparc

  SunOS csu201 5.8 Generic_108528-04 sun4u sparc  

  - Works fine

  - Note, no IPv6 Support, OS lacks RFC 2553 hostname resolution

OpenBSD

  OpenBSD gsb086 2.5 CMPUT#0 i386 unknown

  OpenBSD csu101 2.7 CMPUT#1 i386 unknown  

  - OS needs 'ranlib' to generate the symbol table after 'ar'.. (not using

    GNU ar with the gnu tool chain :<)

  - '2.5' does not have RFC 2553 hostname resolution, but '2.7' does

  - Testing on '2.7' suggests the OS has a bug in its handling of 

    ftruncate on files that have been written via mmap. It fills the page 

    that crosses the truncation boundary with 0's. 

HP-UX

  HP-UX nyquist B.10.20 C 9000/780 2016574337 32-user license

  - Evil OS, does not conform very well to SUS

     1) snprintf exists but is not prototyped, ignore spurious warnings

     2) No socklen_t

     3) Requires -D_XOPEN_SOURCE_EXTENDED for h_errno

    configure should fix the last two (see above)

  - Note, no IPv6 Support, OS lacks RFC 2553 hostname resolution