* ``make [-j]`` --- The ``-j`` specifies the number of jobs (commands) to run
simultaneously. This builds both LLVM and Clang for Debug+Asserts mode.
- The ``--enabled-optimized`` configure option is used to specify a Release
+ The ``--enable-optimized`` configure option is used to specify a Release
build.
* ``make check-all`` --- This run the regression tests to ensure everything
is in working order.
- * ``make update`` --- This command is used to update all the svn repositories
- at once, rather then having to ``cd`` into the individual repositories and
- running ``svn update``.
-
* It is also possible to use CMake instead of the makefiles. With CMake it is
possible to generate project files for several IDEs: Xcode, Eclipse CDT4,
CodeBlocks, Qt-Creator (use the CodeBlocks generator), KDevelop3.
Hardware
--------
-LLVM is known to work on the following platforms:
-
-+-----------------+----------------------+-------------------------+
-|OS | Arch | Compilers |
-+=================+======================+=========================+
-|AuroraUX | x86\ :sup:`1` | GCC |
-+-----------------+----------------------+-------------------------+
-|Linux | x86\ :sup:`1` | GCC |
-+-----------------+----------------------+-------------------------+
-|Linux | amd64 | GCC |
-+-----------------+----------------------+-------------------------+
-|Linux | ARM\ :sup:`13` | GCC |
-+-----------------+----------------------+-------------------------+
-|Solaris | V9 (Ultrasparc) | GCC |
-+-----------------+----------------------+-------------------------+
-|FreeBSD | x86\ :sup:`1` | GCC |
-+-----------------+----------------------+-------------------------+
-|FreeBSD | amd64 | GCC |
-+-----------------+----------------------+-------------------------+
-|MacOS X\ :sup:`2`| PowerPC | GCC |
-+-----------------+----------------------+-------------------------+
-|MacOS X\ :sup:`9`| x86 | GCC |
-+-----------------+----------------------+-------------------------+
-|Cygwin/Win32 | x86\ :sup:`1, 8, 11` | GCC 3.4.X, binutils 2.20|
-+-----------------+----------------------+-------------------------+
-
-LLVM has partial support for the following platforms:
-
-+-------------------+----------------------+-------------------------------------------+
-|OS | Arch | Compilers |
-+===================+======================+===========================================+
-| Windows | x86\ :sup:`1` | Visual Studio 2000 or higher\ :sup:`4,5` |
-+-------------------+----------------------+-------------------------------------------+
-| AIX\ :sup:`3,4` | PowerPC | GCC |
-+-------------------+----------------------+-------------------------------------------+
-| Linux\ :sup:`3,5` | PowerPC | GCC |
-+-------------------+----------------------+-------------------------------------------+
-| Linux\ :sup:`7` | Alpha | GCC |
-+-------------------+----------------------+-------------------------------------------+
-| Linux\ :sup:`7` | Itanium (IA-64) | GCC |
-+-------------------+----------------------+-------------------------------------------+
-| HP-UX\ :sup:`7` | Itanium (IA-64) | HP aCC |
-+-------------------+----------------------+-------------------------------------------+
-| Windows x64 | x86-64 | mingw-w64's GCC-4.5.x\ :sup:`12` |
-+-------------------+----------------------+-------------------------------------------+
+LLVM is known to work on the following host platforms:
+
+================== ===================== =============
+OS Arch Compilers
+================== ===================== =============
+AuroraUX x86\ :sup:`1` GCC
+Linux x86\ :sup:`1` GCC, Clang
+Linux amd64 GCC, Clang
+Linux ARM\ :sup:`4` GCC, Clang
+Linux PowerPC GCC, Clang
+Solaris V9 (Ultrasparc) GCC
+FreeBSD x86\ :sup:`1` GCC, Clang
+FreeBSD amd64 GCC, Clang
+MacOS X\ :sup:`2` PowerPC GCC
+MacOS X x86 GCC, Clang
+Cygwin/Win32 x86\ :sup:`1, 3` GCC
+Windows x86\ :sup:`1` Visual Studio
+Windows x64 x86-64 Visual Studio
+================== ===================== =============
.. note::
#. Code generation supported for Pentium processors and up
#. Code generation supported for 32-bit ABI only
- #. No native code generation
- #. Build is not complete: one or more tools do not link or function
- #. The GCC-based C/C++ frontend does not build
- #. The port is done using the MSYS shell.
- #. Native code generation exists but is not complete.
- #. Binutils 2.20 or later is required to build the assembler generated by LLVM properly.
- #. Xcode 2.5 and gcc 4.0.1 (Apple Build 5370) will trip internal LLVM assert
- messages when compiled for Release at optimization levels greater than 0
- (i.e., ``-O1`` and higher). Add ``OPTIMIZE_OPTION="-O0"`` to the build
- command line if compiling for LLVM Release or bootstrapping the LLVM
- toolchain.
- #. For MSYS/MinGW on Windows, be sure to install the MSYS version of the perl
- package, and be sure it appears in your path before any Windows-based
- versions such as Strawberry Perl and ActivePerl, as these have
- Windows-specifics that will cause the build to fail.
#. To use LLVM modules on Win32-based system, you may configure LLVM
with ``--enable-shared``.
- #. To compile SPU backend, you need to add ``LDFLAGS=-Wl,--stack,16777216`` to
- configure.
#. MCJIT not working well pre-v7, old JIT engine not supported any more.
Note that you will need about 1-3 GB of space for a full LLVM build in Debug
"known to work" versions of the package. The Notes column describes how LLVM
uses the package and provides other details.
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| Package | Version | Notes |
-+==============================================================+=================+=============================================+
-| `GNU Make <http://savannah.gnu.org/projects/make>`_ | 3.79, 3.79.1 | Makefile/build processor |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `GCC <http://gcc.gnu.org/>`_ | 3.4.2 | C/C++ compiler\ :sup:`1` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `TeXinfo <http://www.gnu.org/software/texinfo/>`_ | 4.5 | For building the CFE |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `SVN <http://subversion.tigris.org/project_packages.html>`_ | >=1.3 | Subversion access to LLVM\ :sup:`2` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `python <http://www.python.org/>`_ | >=2.4 | Automated test suite\ :sup:`3` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `perl <http://www.perl.com/download.csp>`_ | >=5.6.0 | Utilities |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `GNU M4 <http://savannah.gnu.org/projects/m4>`_ | 1.4 | Macro processor for configuration\ :sup:`4` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `GNU Autoconf <http://www.gnu.org/software/autoconf/>`_ | 2.60 | Configuration script builder\ :sup:`4` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `GNU Automake <http://www.gnu.org/software/automake/>`_ | 1.9.6 | aclocal macro generator\ :sup:`4` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `libtool <http://savannah.gnu.org/projects/libtool>`_ | 1.5.22 | Shared library manager\ :sup:`4` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `zlib <http://zlib.net>`_ | >=1.2.3.4 | Compression library\ :sup:`5` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
+=========================================================== ============ ==========================================
+Package Version Notes
+=========================================================== ============ ==========================================
+`GNU Make <http://savannah.gnu.org/projects/make>`_ 3.79, 3.79.1 Makefile/build processor
+`GCC <http://gcc.gnu.org/>`_ >=4.7.0 C/C++ compiler\ :sup:`1`
+`python <http://www.python.org/>`_ >=2.5 Automated test suite\ :sup:`2`
+`GNU M4 <http://savannah.gnu.org/projects/m4>`_ 1.4 Macro processor for configuration\ :sup:`3`
+`GNU Autoconf <http://www.gnu.org/software/autoconf/>`_ 2.60 Configuration script builder\ :sup:`3`
+`GNU Automake <http://www.gnu.org/software/automake/>`_ 1.9.6 aclocal macro generator\ :sup:`3`
+`libtool <http://savannah.gnu.org/projects/libtool>`_ 1.5.22 Shared library manager\ :sup:`3`
+`zlib <http://zlib.net>`_ >=1.2.3.4 Compression library\ :sup:`4`
+=========================================================== ============ ==========================================
.. note::
#. Only the C and C++ languages are needed so there's no need to build the
other languages for LLVM's purposes. See `below` for specific version
info.
- #. You only need Subversion if you intend to build from the latest LLVM
- sources. If you're working from a release distribution, you don't need
- Subversion.
#. Only needed if you want to run the automated test suite in the
``llvm/test`` directory.
#. If you want to make changes to the configure scripts, you will need GNU
autoconf (2.60), and consequently, GNU M4 (version 1.4 or higher). You
will also need automake (1.9.6). We only use aclocal from that package.
- #. Optional, adds compression/uncompression capabilities to selected LLVM
+ #. Optional, adds compression / uncompression capabilities to selected LLVM
tools.
Additionally, your compilation host is expected to have the usual plethora of
.. _below:
.. _check here:
-Broken versions of GCC and other tools
---------------------------------------
+Host C++ Toolchain, both Compiler and Standard Library
+------------------------------------------------------
LLVM is very demanding of the host C++ compiler, and as such tends to expose
-bugs in the compiler. In particular, several versions of GCC crash when trying
-to compile LLVM. We routinely use GCC 4.2 (and higher) or Clang. Other
-versions of GCC will probably work as well. GCC versions listed here are known
-to not work. If you are using one of these versions, please try to upgrade your
-GCC to something more recent. If you run into a problem with a version of GCC
-not listed here, please `let us know <mailto:llvmdev@cs.uiuc.edu>`_. Please use
-the "``gcc -v``" command to find out which version of GCC you are using.
-
-**GCC versions prior to 3.0**: GCC 2.96.x and before had several problems in the
-STL that effectively prevent it from compiling LLVM.
-
-**GCC 3.2.2 and 3.2.3**: These versions of GCC fails to compile LLVM with a
-bogus template error. This was fixed in later GCCs.
-
-**GCC 3.3.2**: This version of GCC suffered from a `serious bug
-<http://gcc.gnu.org/PR13392>`_ which causes it to crash in the
-"``convert_from_eh_region_ranges_1``" GCC function.
-
-**Cygwin GCC 3.3.3**: The version of GCC 3.3.3 commonly shipped with Cygwin does
-not work.
-
-**SuSE GCC 3.3.3**: The version of GCC 3.3.3 shipped with SuSE 9.1 (and possibly
-others) does not compile LLVM correctly (it appears that exception handling is
-broken in some cases). Please download the FSF 3.3.3 or upgrade to a newer
-version of GCC.
-
-**GCC 3.4.0 on linux/x86 (32-bit)**: GCC miscompiles portions of the code
-generator, causing an infinite loop in the llvm-gcc build when built with
-optimizations enabled (i.e. a release build).
-
-**GCC 3.4.2 on linux/x86 (32-bit)**: GCC miscompiles portions of the code
-generator at -O3, as with 3.4.0. However gcc 3.4.2 (unlike 3.4.0) correctly
-compiles LLVM at -O2. A work around is to build release LLVM builds with
-"``make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ...``"
-
-**GCC 3.4.x on X86-64/amd64**: GCC `miscompiles portions of LLVM
-<http://llvm.org/PR1056>`__.
-
-**GCC 3.4.4 (CodeSourcery ARM 2005q3-2)**: this compiler miscompiles LLVM when
-building with optimizations enabled. It appears to work with "``make
-ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1``" or build a debug build.
-
-**IA-64 GCC 4.0.0**: The IA-64 version of GCC 4.0.0 is known to miscompile LLVM.
-
-**Apple Xcode 2.3**: GCC crashes when compiling LLVM at -O3 (which is the
-default with ENABLE_OPTIMIZED=1. To work around this, build with
-"``ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2``".
-
-**GCC 4.1.1**: GCC fails to build LLVM with template concept check errors
-compiling some files. At the time of this writing, GCC mainline (4.2) did not
-share the problem.
-
-**GCC 4.1.1 on X86-64/amd64**: GCC `miscompiles portions of LLVM
-<http://llvm.org/PR1063>`__ when compiling llvm itself into 64-bit code. LLVM
-will appear to mostly work but will be buggy, e.g. failing portions of its
-testsuite.
-
-**GCC 4.1.2 on OpenSUSE**: Seg faults during libstdc++ build and on x86_64
-platforms compiling md5.c gets a mangled constant.
-
-**GCC 4.1.2 (20061115 (prerelease) (Debian 4.1.1-21)) on Debian**: Appears to
-miscompile parts of LLVM 2.4. One symptom is ValueSymbolTable complaining about
-symbols remaining in the table on destruction.
-
-**GCC 4.1.2 20071124 (Red Hat 4.1.2-42)**: Suffers from the same symptoms as the
-previous one. It appears to work with ENABLE_OPTIMIZED=0 (the default).
+bugs in the compiler. We are also planning to follow improvements and
+developments in the C++ language and library reasonably closely. As such, we
+require a modern host C++ toolchain, both compiler and standard library, in
+order to build LLVM.
-**Cygwin GCC 4.3.2 20080827 (beta) 2**: Users `reported
-<http://llvm.org/PR4145>`_ various problems related with link errors when using
-this GCC version.
+For the most popular host toolchains we check for specific minimum versions in
+our build systems:
-**Debian GCC 4.3.2 on X86**: Crashes building some files in LLVM 2.6.
+* Clang 3.1
+* GCC 4.7
+* Visual Studio 2012
-**GCC 4.3.3 (Debian 4.3.3-10) on ARM**: Miscompiles parts of LLVM 2.6 when
-optimizations are turned on. The symptom is an infinite loop in
-``FoldingSetImpl::RemoveNode`` while running the code generator.
+Anything older than these toolchains *may* work, but will require forcing the
+build system with a special option and is not really a supported host platform.
+Also note that older versions of these compilers have often crashed or
+miscompiled LLVM.
-**SUSE 11 GCC 4.3.4**: Miscompiles LLVM, causing crashes in ValueHandle logic.
+For less widely used host toolchains such as ICC or xlC, be aware that a very
+recent version may be required to support all of the C++ features used in LLVM.
-**GCC 4.3.5 and GCC 4.4.5 on ARM**: These can miscompile ``value >> 1`` even at
-``-O0``. A test failure in ``test/Assembler/alignstack.ll`` is one symptom of
-the problem.
+We track certain versions of software that are *known* to fail when used as
+part of the host toolchain. These even include linkers at times.
**GCC 4.6.3 on ARM**: Miscompiles ``llvm-readobj`` at ``-O3``. A test failure
in ``test/Object/readobj-shared-object.test`` is one symptom of the problem.
**Clang 3.0 on Mageia 2**. There's a packaging issue: Clang can not find at
least some (``cxxabi.h``) libstdc++ headers.
+**Clang in C++11 mode and libstdc++ 4.7.2**. This version of libstdc++
+contained `a bug <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53841>`__ which
+causes Clang to refuse to compile condition_variable header file. At the time
+of writing, this breaks LLD build.
+
+Getting a Modern Host C++ Toolchain
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This section mostly applies to Linux and older BSDs. On Mac OS X, you should
+have a sufficiently modern Xcode, or you will likely need to upgrade until you
+do. On Windows, just use Visual Studio 2012 as the host compiler, it is
+explicitly supported and widely available. FreeBSD 10.0 and newer have a modern
+Clang as the system compiler.
+
+However, some Linux distributions and some other or older BSDs sometimes have
+extremely old versions of GCC. These steps attempt to help you upgrade you
+compiler even on such a system. However, if at all possible, we encourage you
+to use a recent version of a distribution with a modern system compiler that
+meets these requirements. Note that it is tempting to to install a prior
+version of Clang and libc++ to be the host compiler, however libc++ was not
+well tested or set up to build on Linux until relatively recently. As
+a consequence, this guide suggests just using libstdc++ and a modern GCC as the
+initial host in a bootstrap, and then using Clang (and potentially libc++).
+
+The first step is to get a recent GCC toolchain installed. The most common
+distribution on which users have struggled with the version requirements is
+Ubuntu Precise, 12.04 LTS. For this distribution, one easy option is to install
+the `toolchain testing PPA`_ and use it to install a modern GCC. There is
+a really nice discussions of this on the `ask ubuntu stack exchange`_. However,
+not all users can use PPAs and there are many other distributions, so it may be
+necessary (or just useful, if you're here you *are* doing compiler development
+after all) to build and install GCC from source. It is also quite easy to do
+these days.
+
+.. _toolchain testing PPA:
+ https://launchpad.net/~ubuntu-toolchain-r/+archive/test
+.. _ask ubuntu stack exchange:
+ http://askubuntu.com/questions/271388/how-to-install-gcc-4-8-in-ubuntu-12-04-from-the-terminal
+
+Easy steps for installing GCC 4.8.2:
+
+.. code-block:: console
+
+ % wget ftp://ftp.gnu.org/gnu/gcc/gcc-4.8.2/gcc-4.8.2.tar.bz2
+ % tar -xvjf gcc-4.8.2.tar.bz2
+ % cd gcc-4.8.2
+ % ./contrib/download_prerequisites
+ % cd ..
+ % mkdir gcc-4.8.2-build
+ % cd gcc-4.8.2-build
+ % $PWD/../gcc-4.8.2/configure --prefix=$HOME/toolchains --enable-languages=c,c++
+ % make -j$(nproc)
+ % make install
+
+For more details, check out the excellent `GCC wiki entry`_, where I got most
+of this information from.
+
+.. _GCC wiki entry:
+ http://gcc.gnu.org/wiki/InstallingGCC
+
+Once you have a GCC toolchain, use it as your host compiler. Things should
+generally "just work". You may need to pass a special linker flag,
+``-Wl,-rpath,$HOME/toolchains/lib`` or some variant thereof to get things to
+find the libstdc++ DSO in this toolchain.
+
+When you build Clang, you will need to give *it* access to modern C++11
+standard library in order to use it as your new host in part of a bootstrap.
+There are two easy ways to do this, either build (and install) libc++ along
+with Clang and then use it with the ``-stdlib=libc++`` compile and link flag,
+or install Clang into the same prefix (``$HOME/toolchains`` above) as GCC.
+Clang will look within its own prefix for libstdc++ and use it if found. You
+can also add an explicit prefix for Clang to look in for a GCC toolchain with
+the ``--gcc-toolchain=/opt/my/gcc/prefix`` flag, passing it to both compile and
+link commands when using your just-built-Clang to bootstrap.
+
.. _Getting Started with LLVM:
Getting Started with LLVM
Source release for the LLVM test-suite.
-``llvm-gcc-4.2-x.y.source.tar.gz``
-
- Source release of the llvm-gcc-4.2 front end. See README.LLVM in the root
- directory for build instructions.
-
-``llvm-gcc-4.2-x.y-platform.tar.gz``
-
- Binary release of the llvm-gcc-4.2 front end for a specific platform.
-
.. _checkout:
Checkout LLVM from Subversion
following releases are located in the following subdirectories of the '``tags``'
directory:
+* Release 3.4: **RELEASE_34/final**
+* Release 3.3: **RELEASE_33/final**
+* Release 3.2: **RELEASE_32/final**
* Release 3.1: **RELEASE_31/final**
* Release 3.0: **RELEASE_30/final**
* Release 2.9: **RELEASE_29/final**
``checkout`` each working branch individually and ``rebase`` it on top of its
parent branch.
-For those who wish to be able to update an llvm repo in a simpler fashion,
-consider placing the following Git script in your path under the name
-``git-svnup``:
-
-.. code-block:: bash
-
- #!/bin/bash
+For those who wish to be able to update an llvm repo/revert patches easily using
+git-svn, please look in the directory for the scripts ``git-svnup`` and
+``git-svnrevert``.
- STATUS=$(git status -s | grep -v "??")
+To perform the aforementioned update steps go into your source directory and
+just type ``git-svnup`` or ``git svnup`` and everything will just work.
- if [ ! -z "$STATUS" ]; then
- STASH="yes"
- git stash >/dev/null
- fi
+If one wishes to revert a commit with git-svn, but do not want the git hash to
+escape into the commit message, one can use the script ``git-svnrevert`` or
+``git svnrevert`` which will take in the git hash for the commit you want to
+revert, look up the appropriate svn revision, and output a message where all
+references to the git hash have been replaced with the svn revision.
- git fetch
- OLD_BRANCH=$(git rev-parse --abbrev-ref HEAD)
- git checkout master 2> /dev/null
- git svn rebase -l
- git checkout $OLD_BRANCH 2> /dev/null
-
- if [ ! -z $STASH ]; then
- git stash pop >/dev/null
- fi
-
-Then to perform the aforementioned update steps go into your source directory
-and just type ``git-svnup`` or ``git svnup`` and everything will just work.
-
-To commit back changes via git-svn, use ``dcommit``:
+To commit back changes via git-svn, use ``git svn dcommit``:
.. code-block:: console
target names that you want available in llc. The target names use all lower
case. The current set of targets is:
- ``arm, cpp, hexagon, mblaze, mips, mipsel, msp430, powerpc, ptx, sparc, spu,
- x86, x86_64, xcore``.
+ ``arm, cpp, hexagon, mips, mipsel, msp430, powerpc, ptx, sparc, spu,
+ systemz, x86, x86_64, xcore``.
``--enable-doxygen``
The result of such a build is executables that are not runnable on on the build
host (--build option) but can be executed on the compile host (--host option).
+Check :doc:`HowToCrossCompileLLVM` and `Clang docs on how to cross-compile in general
+<http://clang.llvm.org/docs/CrossCompilation.html>`_ for more information
+about cross-compiling.
+
The Location of LLVM Object Files
---------------------------------
This directory holds the source code for the LLVM assembly language parser
library.
-``llvm/lib/BitCode/``
+``llvm/lib/Bitcode/``
This directory holds code for reading and write LLVM bitcode.
This directory contains projects that are not strictly part of LLVM but are
shipped with LLVM. This is also the directory where you should create your own
-LLVM-based projects. See ``llvm/projects/sample`` for an example of how to set
-up your own project.
+LLVM-based projects.
``llvm/runtime``
----------------
Clang works just like GCC by default. The standard -S and -c arguments
work as usual (producing a native .s or .o file, respectively).
-#. Next, compile the C file into a LLVM bitcode file:
+#. Next, compile the C file into an LLVM bitcode file:
.. code-block:: console