#34231: ImageMagick: should not depend on pango + fix openMP ---------------------------------------+------------------------------------ Reporter: frederic.devernay@… | Owner: ryandesign@… Type: defect | Status: new Priority: Normal | Milestone: Component: ports | Version: 2.0.4 Keywords: haspatch | Port: ImageMagick ---------------------------------------+------------------------------------ Changes (by ryandesign@…): * owner: macports-tickets@… => ryandesign@… * keywords: => haspatch Old description:

this patch fixes two things: - if pango is installed, configure detects it and thus it becomes a "hidden dependency". TYhis patch makes the dependency exlicit with the +pango variant - OpenMP is broken in gcc 4.0 and 4.2, so disable it on these compilers.

New description: this patch fixes two things: - if pango is installed, configure detects it and thus it becomes a "hidden dependency". TYhis patch makes the dependency exlicit with the +pango variant - OpenMP is broken in gcc 4.0 and 4.2, so disable it on these compilers. -- Comment: Replying to [ticket:34231 frederic.devernay@…]:

- if pango is installed, configure detects it and thus it becomes a "hidden dependency". TYhis patch makes the dependency exlicit with the +pango variant

Thanks; I had overlooked that. Committed that part in r92396 along with a minor version update (since a revision increase would have been needed otherwise, and we might as well instead pull in some upstream bug fixes while we're at it). Note that I [ticket:14540 rewrote] the pango dependency so that pango-devel could satisfy it. This also means we have to close #20923 as wontfix, which I'm quite happy to do.

- OpenMP is broken in gcc 4.0 and 4.2, so disable it on these compilers.

That's news to me. You should probably report that to the developers of ImageMagick so that they can fix their use of OpenMP on gcc 4.2. My understanding is that ImageMagick did not attempt to use OpenMP automatically on gcc earlier than 4.2, but that it could still be added. See also #15945 and #24944 and #32642. -- Ticket URL: <https://trac.macports.org/ticket/34231#comment:1> MacPorts <http://www.macports.org/> Ports system for Mac OS

#34231: ImageMagick: should not depend on pango + fix openMP ---------------------------------------+------------------------------------ Reporter: frederic.devernay@… | Owner: ryandesign@… Type: defect | Status: new Priority: Normal | Milestone: Component: ports | Version: 2.0.4 Keywords: haspatch | Port: ImageMagick ---------------------------------------+------------------------------------ Comment(by ryandesign@…): Replying to [comment:2 frederic.devernay@…]:

Here's the proper reference for the gcc 4.2/4.3 bug with OpenMP: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36242#c4 [[br]] [[br]] to cite Jakup, GCC OpenMP guru: [[br]] "Jakub Jelinek 2008-06-11 20:29:19 UTC [[br]] [[br]] Using OpenMP pragmas in multiple pthread_create created threads concurrently isn't supported in 4.2/4.3. There is a support for it on the trunk since a few days ago though."

And does ImageMagick use OpenMP pragmas in multiple pthread_create-created threads concurrently? What is the consequence—is there a crash? If so, can you attach a crash log? How can I reproduce the problem on my own system? I am on Snow Leopard with Xcode 3.2.6 so my ImageMagick is compiled with Apple gcc 4.2.1 so it should exhibit the problem.

gcc 4.2 is for old geezers anyway (gcc 4.2.1 was released almost five years ago!)

Apple's version of gcc 4.2.1 is the default compiler in Xcode 3.2.6, the last free version of Xcode for Snow Leopard. It's also the last version of gcc Apple will ever ship in Xcode. For these reasons it's still a relevant version of gcc for OS X users.

here's another report about that OpenMP bug in another context: http://lists.apple.com/archives/coreaudio-api/2009/May/msg00035.html

I don't think that's the same problem. They're talking about problems using OpenMP from a "time constraint thread" which "is very different from a normal thread context" and the guess is "that OpenMP has some baseline incompatibility when running in this context". The thread also says gcc 4.4 still exhibits the problem, whereas the problem you're describing should be fixed by that version. If there is really a problem with OpenMP when compiled by gcc 4.2.1 and earlier, then in light of the requests in #15945 and #24944 to provide options to enable or disable OpenMP at install time, what we should do is add an openmp variant, make it on by default when the compiler is clang or llvm-gcc-4.2, and off by default otherwise. That should enable OpenMP on Lion and later, and on Snow Leopard with Xcode 4, and disable it otherwise. Furthermore perhaps we could offer Xcode 3 users on Leopard and Snow Leopard the option of turning on OpenMP support by changing the compiler to llvm-gcc-4.2 or clang, if that works—the version of clang in Xcode 3 is old so I'm a little skeptical of that anyway. -- Ticket URL: <https://trac.macports.org/ticket/34231#comment:3> MacPorts <http://www.macports.org/> Ports system for Mac OS

#34231: ImageMagick: should not depend on pango + fix openMP ---------------------------------------+------------------------------------ Reporter: frederic.devernay@… | Owner: ryandesign@… Type: defect | Status: new Priority: Normal | Milestone: Component: ports | Version: 2.0.4 Keywords: haspatch | Port: ImageMagick ---------------------------------------+------------------------------------ Comment(by ryandesign@…): Thank you for the additional information. While I do of course want to "do the right thing" (or the best thing) by default, users have requested the ability to turn openmp support on when it was off by default (#15945) or off when it was on by default (#24944). These users apparently feel there is value to being able to select this, so I would like to accommodate their wishes, just as I would like to accommodate the wishes you've expressed in this ticket. Although you say "IM doesn't really benefit from using OpenMP", clearly the developers of ImageMagick must disagree with you or else they wouldn't have added OpenMP support to ImageMagick, so I am trying to come up with a solution that gives users the choice if possible. It's not really important that later versions of gcc would work with openmp, since there is no supported circumstance in which ImageMagick would ever be compiled with a later version of gcc in MacPorts. The only compilers ImageMagick might be compiled with today are the ones that come with Xcode; by default those are: gcc 4.0 on Tiger and Leopard, gcc 4.2 on Snow Leopard with Xcode 3, llvm-gcc-4.2 on Xcode 4.0 and 4.1, and clang on Xcode 4.2 and up. I was not suggesting that we should allow users to compile ImageMagick with gcc and with openmp on. Rather, I was suggesting that Xcode 3 and up includes versions of llvm-gcc-4.2 and clang. Although the default compiler for Xcode 3 is a version of gcc, we could set ImageMagick to compile with llvm-gcc-4.2 or clang instead, thereby allowing openmp to function properly. Assuming the old versions of llvm-gcc-4.2 or clang in Xcode 3 work well enough to compile ImageMagick at all, we could either switch the compiler unconditionally, or conditionally only when openmp support is requested. If necessary we could even make ImageMagick install the clang-3.0 port and use that to compile ImageMagick, though since that's a rather heavy dependency it would be best to avoid that if possible. -- Ticket URL: <https://trac.macports.org/ticket/34231#comment:5> MacPorts <http://www.macports.org/> Ports system for Mac OS