navigation bar top
navigation bar logonavigation item HOMEnavigation item SOFTWAREnavigation item ABOUT MEnavigation item PICTURESnavigation item FUNnavigation item LINKSnavigation bar tail
navigation bar bottomnavigation bar highlight line sectionnavigation bar highlight line sectionnavigation bar highlight line sectionnavigation bar highlight line sectionnavigation bar highlight line sectionnavigation bar highlight line sectionnavigation bar highlight line tail
Leopard : Four-Way Universal Binaries
Mac OS X — 30 Oct 2007 14:13 — 1002 days ago

A post in my user forum made me aware of the fact that in Leopard, some binaries are not just two-way (PPC/Intel) but four-way Universal Binaries. The four variants are Intel 32bit, Intel 64bit, PPC 32bit and PPC 64bit.

Examples are the Apache web server binary and all its modules:

$ file /usr/sbin/httpd /usr/sbin/httpd: Mach-O universal binary with 4 architectures /usr/sbin/httpd (for architecture ppc7400): Mach-O executable ppc /usr/sbin/httpd (for architecture ppc64): Mach-O 64-bit executable ppc64 /usr/sbin/httpd (for architecture i386): Mach-O executable i386 /usr/sbin/httpd (for architecture x86_64): Mach-O 64-bit executable x86_64 $ file /usr/libexec/apache2/mod_vhost_alias.so mod_vhost_alias.so: Mach-O universal binary with 4 architectures mod_vhost_alias.so (for architecture ppc7400): Mach-O bundle ppc mod_vhost_alias.so (for architecture ppc64): Mach-O 64-bit bundle ppc64 mod_vhost_alias.so (for architecture i386): Mach-O bundle i386 mod_vhost_alias.so (for architecture x86_64): Mach-O 64-bit bundle x86_64

I think it wasn’t that way in Tiger?

Only few of the command line binaries are four-way universal:
$ file /usr/bin/* /usr/sbin/* | grep '4 architectures' /usr/bin/auvaltool: Mach-O universal binary with 4 architectures /usr/bin/mpic++: Mach-O universal binary with 4 architectures /usr/bin/mpicc: Mach-O universal binary with 4 architectures /usr/bin/mpicxx: Mach-O universal binary with 4 architectures /usr/bin/mpiexec: Mach-O universal binary with 4 architectures /usr/bin/mpif77: Mach-O universal binary with 4 architectures /usr/bin/mpif90: Mach-O universal binary with 4 architectures /usr/bin/mpirun: Mach-O universal binary with 4 architectures /usr/bin/ompi_info: Mach-O universal binary with 4 architectures /usr/bin/opal_wrapper: Mach-O universal binary with 4 architectures /usr/bin/orted: Mach-O universal binary with 4 architectures /usr/bin/orterun: Mach-O universal binary with 4 architectures /usr/sbin/httpd: Mach-O universal binary with 4 architectures
Many more are two-way:
$ file /usr/bin/* /usr/sbin/* | grep '2 architectures' | wc -l 857

The graphical end-user apps seem to be two-way too:

$ file /Applications/GarageBand.app/Contents/MacOS/GarageBand /Applications/GarageBand.app/Contents/MacOS/GarageBand: Mach-O universal binary with 2 architectures

The interesting question for me is if I need to start building my PHP5 module as four-way universal binary. That could mean a lot of additional work because not all of the many open source libraries I have to include might even be 64bit-clean.

Update: Apparently I do...

Another observation: While working on a PHP5 module build I stumbled upon what seems to be an inconsistency between architectures in the Apple-suppplied libiconv library. The PHP build fails in the link stage. The linker cannot find the symbol _libiconv in two of the four architectures.

Sure enough, the two 64bit architectures in the fat library do not seem to define this symbol:

$ for arch in i386 ppc7400 x86_64 ppc64; do echo $arch; nm -arch $arch /usr/lib/libiconv.dylib | grep _libiconv$; done i386 0000bc8d T _libiconv ppc7400 0000de7c T _libiconv x86_64 ppc64

The build succeeds if I build my own universal libiconv from source. I wonder why Apple’s PHP5 works with the system-supplied libiconv.

Permalink | 3 Comments

Comments
Posted by Ralph Martin on 31 Oct 2007 22:10

Marc

I think there is a serious problem.

httpd is started as x86_64 in Leopard on Intel (64 bit)
Mysql is currently only available prebuilt as i386 on Intel (32 bit) .

As these have different architectures, I dont *think* you can make a PHP module which plays nice with both of these at the same time (even if you compile as a 4-way binary).

Correct me if I am wrong.

But I think this means we have to either wait until there's a 64 bit MYSQL, or build one ourselves,
OR
force httpd to run in 32 bit mode.

Comments?

Posted by Ralph Martin on 31 Oct 2007 22:34

I take it back!

PHP has to be LINKED against a 64 bit capable MYSQL library.

The running mysqld is a separate process which can be a 32 bit.

Marc, just delete this and the previous comment.

[Red face]

Posted by james on 6 Nov 2007 05:43

I was able to get PHP to compile for x86_64 by modifying the Makefile as follows:

CFLAGS_CLEAN = -g -O2 -I/usr/include -arch x86_64 -isysroot /Developer/SDKs/MacOSX10.5.sdk
EXTRA_LDFLAGS = -arch x86_64 -isysroot /Developer/SDKs/MacOSX10.5.sdk -Wl,-syslibroot,/Developer/SDKs/MacOSX10.5.sdk

However, I only got it working with --with-apxs2 --without-iconv. I couldn't get it working with --with-mysql since I don't have x86_64 client libraries. I downloaded the mysql source and tried to compile it as x86_64, but I don't know enough about what I'm doing to get that to work. I assume since the Apple supplied mysqld isn't x86_64, that it's not possible at this time to compile it as such? I would assume however, that compiling just the client would work... but I can't figure out how to do that.

One thing I noted was that PHP didn't have to be a 4-way binary to work with the 4-way apache. I only compiled it for the x86_64 arch. Not useful for distribution... But something people might be interested in if rolling your own becomes easier.

Powered By blojsom