I've been building Clang for years on Linux and OS X. From the LLVM Download page, I've always used the following sources:
LLVM (LLVM source)
Compiler Front End (Clang source)
Compiler RT (Runtime source)
Compiler Tools (Tools Extra sources)
The recipe I am using to download, build and install Clang 3.5 can be found at Clang 3.5 download, build and install script.
Its works great on OS X 10.7 and 10.8, and I've never needed the libc++ gear on OS X 10.7.x or 10.8.x (that's about 2010 or so through current).
Question: when does one need the libc++ and libc++ ABI sources?
I'm trying to help troubleshoot the inability to compile a simple C++ "Hello World" program on OS X 10.9. Clang 3.5 installed in /usr/local (just like the others), but its failing to find headers (like <iostream>) and it encounters undefined symbols during link (like "std::ostream::operator<<(std::ostream& (*)(std::ostream&))").
I'm wondering if 10.7 and 10.8 had headers and libraries where previous versions of Clang expected, but 10.9 needs them built and installed.
Question: is this symptomatic of a missing libc++ and libc++ ABI?
You should have the libc++ sources checked out when building/installing clang such that you will also install the C++ STL.
If you don't have a libc++ runtime on your system, you should checkout and install libc++abi and libc++ which can be done standalone and independently of their checkout in your llvm/clang install.
As reference, I suggest you take a look at the libcxxabi, libcxx, libunwind, and llvm-X.Y ports in MacPorts which show how I've configured these projects to build on Leopard through Yosemite.
Related
We want our software to support OSX Versions down to 10.9. In XCode you can set the target version, that is no problem, but we have another lib that gets linked in the projekt which is built using cmake. Now XCode complains that the lib is build for 10.11, but our project is 10.9. Can I somehow tell clang on the command line to compile for an older version?
The only information I have found is to set OSX_VERSION as variable, but it seems to have no effect.
Thanks in advance!
From clang --help:
-mmacosx-version-min=<value>
Set Mac OS X deployment target
Do be on the lookout for gotchas with earlier deployment targets, and make sure you test all the OS versions you support.
I'm trying to install Gforth on my MacBook Air (running OS X Mavericks (10.9)), but a brew install gforth produces the following error:
Error: gforth dependency libffi was built with the following
C++ standard library: libstdc++ (from clang)
This is incompatible with the standard library being used
to build gforth: libc++ (from clang)
Please reinstall libffi using a compatible compiler.
I know what the issue is (libffi was built with an older version of the C++ standard library), but I'm not sure how to fix this issue with Homebrew. Can I uninstall libffi and reinstall it with libc++ via Homebrew, or do I need to resort to more drastic measures?
I'm trying to build a project which is originally written for archlinux. The building process works fine on that archlinux but has a huge amount of errors when I tried to build it on my mac. The project is basically written in C++11 so it's very unstable. I think there has something to do with the compiler because the clang version in mac is 4.2(It actually shows 'Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn)' when I type clang --version) and 3.3 for linux. So I want a different version of clang, perhaps 3.3. How Can I specify the version of my compiler when trying to build the project?
Some might argue this belongs on apple.stackexchange.com, but I'm not sure C++11 tags grab a lot of attention there:)
Xcode 5.0 is now available from the App Store. Install it, go to Preferences -> Downloads, and install the Command Line Tools. However...
First, you will need to go to Preferences -> Accounts and add your Apple ID. For some reason, the Command Line Tools download requires an account login. I don't know what the rationale for this is.
> clang -v
Apple LLVM version 5.0 (clang-500.2.75) (based on LLVM 3.3svn)
If you are willing to build from the command line, using make for example (which sounds likely given the project is from Linux), then install Macports and install whatever version of clang you would like:
$sudo port install clang-3.1
$sudo clang_select
Note that this version of clang shouldn't interfere with the Xcode Command Line package if you are will to invoke the Xcode version using xcrun clang instead of plain old clang.
I heavily use the c++0x/c++11 features in my project, particularly code blocks and shared pointers. When I upgraded my OS to 10.8 Mountain Lion (Edit: From 10.7), I was forced to upgrade Xcode. In upgrading Xcode, I lost the ability to compile my c++ project for deployment on 10.6 systems as I get the following error.
clang: error: invalid deployment target for -stdlib=libc++ (requires Mac OS X 10.7 or later)
It appears that Apple is trying to force people to upgrade by not allowing developers to support Snow Leopard. This makes me angry. Arrrggg!!!
What can I do?
EDIT: After several comments back and forth, it should be made clear that 10.6 does not ship with system libc++ libraries. As a result, simply being able to build a libc++ project for 10.6 deployment is not enough. You would also need to include libc++ binaries with your 10.6 distribution or statically link to them. So lets continue with the premise that I am already doing that.
UPDATE 1: This question was originally intended for use with Xcode 4.5.2 (the latest version at the time the question was asked). I have since upgraded to Xcode 4.6.3 and have updated the question and answer to reflect that.
UPDATE 2: I've since upgraded to Xcode 5.0.2. The technique listed in the selected answer below still works as expected.
UPDATE 3: I've since upgraded to Xcode 5.1. The technique listed in the answer below does not yet work for this version!
UPDATE 4: I've since upgraded to Xcode 6.0.1. The technique listed in the selected answer below appears to be working again.
UPDATE 5: I've since upgraded to Xcode 7.1.1. The technique listed in the selected answer below appears to be working again, with one important caveat. You must disable Bitcoding used for AppThinning since the opensource LLVM version doesn't support it (nor should it). So you will need to switch between the open source and Apple LLVM clang in order to compile for both 10.6 and tvOS/watchOS (since Bitcoding is required for those OSes).
Apple has decided to only officially support libc++ on 10.7 or higher. So the version of clang/llvm that ships with Xcode checks to see if the deployment target is set for 10.6 when using libc++, and prevents you from compiling. However, this flag is not included in the open source version of clang/llvm.
Take a look at this thread:
http://permalink.gmane.org/gmane.comp.compilers.clang.devel/17557
So, to compile a project that is using c++11 for 10.6 deployment, you need to give Xcode the open source version. Here is one way of doing it:
Download the open source version of clang from here (use LLVM 3.1 for Xcode 4.5.x; use LLVM 3.2 for Xcode 4.6.x; use LLVM 3.3 for Xcode 5.0.x; use LLVM 3.5.0 for XCode 6.0.1; use LLVM 3.7.0 for XCode 7.1.1):
http://llvm.org/releases/download.html
Make a backup of Xcode's default clang compiler and put it in a safe place (In case you screw up!)
This is located at:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
Replace the default clang compiler with the one you downloaded from [1]
chown the clang binary for root:wheel with sudo chown root:wheel clang from the bin directory listed in [2].
Startup Xcode and compile!
UPDATE #1: This technique does not currently work for Xcode 5.1 or newer, which relies on LLVM 3.4. When I get some more time, I will try and find a solution to post here. But if someone comes up with a solution before me, they should post it as an answer.
UPDATE #2: Unfortunately I can't remember if I ever found a solution for Xcode 5.1, however I can confirm that the technique does still work for Xcode 6.0.1. I haven't tested on versions newer than that, but it could still work.
UPDATE #3: This technique appears to still work with XCode 7.1.1 using LLVM 3.7.0. However, the open source LLVM clang does not support Bitcoding. So you will need to switch between the open source compiler and Apple's compiler in order to develop for both 10.6 and tvOS/watchOS (which require Bitcoding).
P.S.: The Mac OS X binaries for LLVM 3.4 and 3.5.0 are listed as "Clang for Darwin 10.9" at www.llvm.org/releases/download.html rather than as "Clang Binaries for Mac OS X" in previous versions.
While Xcode 4.5.x is the current default version on OS X 10.8, you can have other, older versions of Xcode, such as Xcode 3.2.6 for OS X 10.6, available on 10.8 as long as you have access to their installers. You will need to ensure you install each one to a unique directory. Also, one thing you can't or shouldn't do is to install the Command Line Tools component or installer package of older Xcodes onto your 10.8 system, i.e. not into /usr or /System/Library. You can use the xcodebuild, xcode-select, and xcrun command line tools to access non-default Xcode components. See their man pages for more info. Older versions of Xcode are available to registered users of developer.apple.com
UPDATE: Based on your subsequent comments, I believe I did miss the point of the question and also that you had answered your own question. I think what you are saying is that you upgraded from 10.7 to 10.8, not from 10.6 to 10.8 as I assumed. You also did not make clear in the original question that you were distributing your own version of Apple's libc++ and friends from 10.7 with your own app. Apple does not make it easy in Xcode to do something like that since it has long been Apple's policy to discourage static linking with libs or distributing duplicate libs (which in some cases could violate license terms). There are good reasons for that policy.
The bottom line is that libc++ is only shipped with OS X 10.7 or later systems. There never was Apple support for libc++ in 10.6, so it's misleading to say it was removed. If you want to supply an app that is deployable on 10.6 and later systems and depends on libc++, the safest approach is to build your own clang/llvm and libc++ targeted for OS X 10.6 and use that to build your project. There are various ways to do that, probably the easiest is to use the MacPorts versions and set the deployment target in MacPorts for 10.6. Or build it all from scratch yourself. But modifying the clang compiler within Xcode 4.5 is a bad idea. And copying Apple libraries to one's app is generally a bad idea.
If you have a solution that works for you, great. But I would not recommend it to others.
Here's my problem: I want to use C++11 features provided by either gcc or clang. However, I have these requirements:
I'm using a mac
I'm dependent on a bunch of libraries provided by homebrew (and really don't want to compile them myself). Specifically OSG, which itself is dependent on a ton of other libraries. And boost, though I can always compile that myself.
Homebrew seems to only want to use gcc (please correct me if I'm wrong). I can't find any options to switch to LLVM instead. While I understand that this might be due to the fact that not all libraries are compatible with LLVM yet, this would still be a nice feature for those that are.
The version of gcc that comes pre-installed on a mac of gcc is 4.2. gcc 4.2 doesn't have the c++11 features required. I've installed 4.7 via homebrew, but searches for how to set homebrew to use it all say don't do it (gcc 4.2 on the mac is not the vanilla version, so the 4.7 version I got won't be able to compile some things).
My questions are: Does anyone have any suggestions or fixes they have implemented to get around this problem? Should I give up on Homebrew? Does anyone know if Homebrew has a plan to switch to LLVM in the future? Does anyone have any upgrade-plan for how to deal with these incompatibilities?
I don't see how homebrew can continue to depend on gcc 4.2 in the long run, but haven't found any real discussion on this matter.
The default GCC on Mac is not real GCC of GNU. It's LLVM-GCC in fact, which is a branch of GCC. Several years ago, LLVM-GCC was terminated, and replaced with DragonEgg, which is a GCC plugin to use LLVM as a GCC backend.
LLVM-GCC is just a compiler frontend, whose role is using GCC frontend to translate the source code into LLVM IR[Intro to LLVM 11.3]. Once IR generated, LLVM backend will use it to generate binary code. This step has nothing to do with GCC.
The above goal was fully achieved from 10.7, whose components were all compiled by clang, a frontend provided by LLVM.
But Apple still kept LLVM-GCC and GCC runtime libraries. I guess its purpose might be providing a opportunity to compile some code GCC ONLY.
Now let's answer your questions:
If you want to use C++11 features, use clang++ -stc=c++11 -stdlib=libc++ instead. And clang might have already supported all c++11 features.
If you want homebrew supporting LLVM, it has already supported, at least on backend.
If you want homebrew using clang as a compiler frontend, it depends on homebrew community schedule. For example, you can append --with-c++11 argument to use clang to compile boost.But you cannot use this argument when brew install autoconf. In fact, some components might not be compiled correctly by clang.
If you know it can be compiled by clang but homebrew hasn't supported yet, you have to hack the corresponding ruby script at $HOMEBREW_ROOT/Library/Formula directory. Fortunately, in most of cases, replacing ./configure blablabla with ./configure blablabla CXX=clang++ -stc=c++11 -stdlib=libc++ works well. And by the way, if your hack is successful, please make a pull request to homebrew.
So, try it and have a fun.
I have an OS X Mountain Lion environment and use C++11. In this answer I'll break your requirement for not compiling your own stuff.
I use Homebrew and, I must say, I advise you to give up on depending on it to provide you clang and libc++ and all its formulas built with them.
What I've done, and I like, is
clone llvm, clang and libc++ from repositories.
install to /opt/local and put /opt/local/bin at top on /etc/paths.
build my development stuff with my new clang.
let Homebrew for installing tools like git and things I'll not develop for, just use.
I've followed clang build instructions for installing it to /opt/local.
For libc++, one detail: after running the buildit script, I've symlinked the include directory to /opt/local/lib/c++/v1 (clang on /opt/local looks for this as default directory), and also symlinked the libs to /opt/local/lib/ (but look that binaries will not automatically link to libc++ on /opt/local/lib. You must use install_name_tool for that).
use
clang++ -std=c++11 -stdlib=libc++
you can also install latest gcc from homebrew-dups
brew install [flags] https://raw.github.com/Homebrew/homebrew-dupes/master/gcc.rb
For LLVM, brew install --HEAD llvm. To use clang or a brew-installed gcc, add --with-clang or --with-gcc=gcc-x.x where x.x is the version you want.