-.. _getting_started:
-
====================================
Getting Started with the LLVM System
====================================
+.. contents::
+ :local:
+
Overview
========
* ``../llvm/configure [options]``
Some common options:
- * ``--prefix=directory`` ---
-
- Specify for *directory* the full pathname of where you want the LLVM
- tools and libraries to be installed (default ``/usr/local``).
-
- * ``--enable-optimized`` ---
+ * ``--prefix=directory`` --- Specify for *directory* the full pathname of
+ where you want the LLVM tools and libraries to be installed (default
+ ``/usr/local``).
- Compile with optimizations enabled (default is NO).
+ * ``--enable-optimized`` --- Compile with optimizations enabled (default
+ is NO).
- * ``--enable-assertions`` ---
-
- Compile with assertion checks enabled (default is YES).
+ * ``--enable-assertions`` --- Compile with assertion checks enabled
+ (default is YES).
* ``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 ``--enabled-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
- also possible to generate project files for several IDEs: Eclipse CDT4,
+ possible to generate project files for several IDEs: Xcode, Eclipse CDT4,
CodeBlocks, Qt-Creator (use the CodeBlocks generator), KDevelop3.
* If you get an "internal compiler error (ICE)" or test failures, see
+-----------------+----------------------+-------------------------+
|Linux | amd64 | GCC |
+-----------------+----------------------+-------------------------+
+|Linux | ARM\ :sup:`13` | GCC |
++-----------------+----------------------+-------------------------+
|Solaris | V9 (Ultrasparc) | GCC |
+-----------------+----------------------+-------------------------+
|FreeBSD | x86\ :sup:`1` | GCC |
.. note::
- Code generation supported for Pentium processors and up
-
#. Code generation supported for Pentium processors and up
#. Code generation supported for 32-bit ABI only
#. No native code generation
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
mode, depending on the system (it is so large because of all the debugging
+--------------------------------------------------------------+-----------------+---------------------------------------------+
| `SVN <http://subversion.tigris.org/project_packages.html>`_ | >=1.3 | Subversion access to LLVM\ :sup:`2` |
+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `DejaGnu <http://savannah.gnu.org/projects/dejagnu>`_ | 1.4.2 | Automated test suite\ :sup:`3` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `tcl <http://www.tcl.tk/software/tcltk/>`_ | 8.3, 8.4 | Automated test suite\ :sup:`3` |
-+--------------------------------------------------------------+-----------------+---------------------------------------------+
-| `expect <http://expect.nist.gov/>`_ | 5.38.0 | Automated test suite\ :sup:`3` |
+| `python <http://www.python.org/>`_ | >=2.4 | Automated test suite\ :sup:`3` |
+--------------------------------------------------------------+-----------------+---------------------------------------------+
| `perl <http://www.perl.com/download.csp>`_ | >=5.6.0 | Utilities |
+--------------------------------------------------------------+-----------------+---------------------------------------------+
``-O0``. A test failure in ``test/Assembler/alignstack.ll`` is one symptom of
the problem.
+**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.
+
**GNU ld 2.16.X**. Some 2.16.X versions of the ld linker will produce very long
warning messages complaining that some "``.gnu.linkonce.t.*``" symbol was
defined in a discarded section. You can safely ignore these messages as they are
symptom is an error about cyclic dependencies. We recommend upgrading to a
newer version of Gold.
+**Clang 3.0 with libstdc++ 4.7.x**: a few Linux distributions (Ubuntu 12.10,
+Fedora 17) have both Clang 3.0 and libstdc++ 4.7 in their repositories. Clang
+3.0 does not implement a few builtins that are used in this library. We
+recommend using the system GCC to compile LLVM and Clang in this case.
+
+**Clang 3.0 on Mageia 2**. There's a packaging issue: Clang can not find at
+least some (``cxxabi.h``) libstdc++ headers.
+
.. _Getting Started with LLVM:
Getting Started with LLVM
Binary release of the llvm-gcc-4.2 front end for a specific platform.
+.. _checkout:
+
Checkout LLVM from Subversion
-----------------------------
If you would like to get the LLVM test suite (a separate package as of 1.4), you
get it from the Subversion repository:
-.. code-block:: bash
+.. code-block:: console
% cd llvm/projects
% svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite
the LLVM configure script as well as automatically updated when you run ``svn
update``.
-GIT mirror
+Git Mirror
----------
-GIT mirrors are available for a number of LLVM subprojects. These mirrors sync
+Git mirrors are available for a number of LLVM subprojects. These mirrors sync
automatically with each Subversion commit and contain all necessary git-svn
marks (so, you can recreate git-svn metadata locally). Note that right now
-mirrors reflect only ``trunk`` for each project. You can do the read-only GIT
+mirrors reflect only ``trunk`` for each project. You can do the read-only Git
clone of LLVM via:
-.. code-block:: bash
+.. code-block:: console
% git clone http://llvm.org/git/llvm.git
If you want to check out clang too, run:
-.. code-block:: bash
+.. code-block:: console
- % git clone http://llvm.org/git/llvm.git
% cd llvm/tools
% git clone http://llvm.org/git/clang.git
+If you want to check out compiler-rt too, run:
+
+.. code-block:: console
+
+ % cd llvm/projects
+ % git clone http://llvm.org/git/compiler-rt.git
+
+If you want to check out the Test Suite Source Code (optional), run:
+
+.. code-block:: console
+
+ % cd llvm/projects
+ % git clone http://llvm.org/git/test-suite.git
+
Since the upstream repository is in Subversion, you should use ``git
pull --rebase`` instead of ``git pull`` to avoid generating a non-linear history
in your clone. To configure ``git pull`` to pass ``--rebase`` by default on the
master branch, run the following command:
-.. code-block:: bash
+.. code-block:: console
% git config branch.master.rebase true
branch, and ``mybranch`` is rebased onto ``master``. At first you may check
sanity of whitespaces:
-.. code-block:: bash
+.. code-block:: console
% git diff --check master..mybranch
The easiest way to generate a patch is as below:
-.. code-block:: bash
+.. code-block:: console
% git diff master..mybranch > /path/to/mybranch.diff
But you may generate patchset with git-format-patch. It generates by-each-commit
patchset. To generate patch files to attach to your article:
-.. code-block:: bash
+.. code-block:: console
% git format-patch --no-attach master..mybranch -o /path/to/your/patchset
If you would like to send patches directly, you may use git-send-email or
git-imap-send. Here is an example to generate the patchset in Gmail's [Drafts].
-.. code-block:: bash
+.. code-block:: console
% git format-patch --attach master..mybranch --stdout | git imap-send
Then, your .git/config should have [imap] sections.
-.. code-block:: bash
+.. code-block:: ini
[imap]
host = imaps://imap.gmail.com
To set up clone from which you can submit code using ``git-svn``, run:
-.. code-block:: bash
+.. code-block:: console
% git clone http://llvm.org/git/llvm.git
% cd llvm
% git config svn-remote.svn.fetch :refs/remotes/origin/master
% git svn rebase -l
+Likewise for compiler-rt and test-suite.
+
To update this clone without generating git-svn tags that conflict with the
-upstream git repo, run:
+upstream Git repo, run:
-.. code-block:: bash
+.. code-block:: console
% git fetch && (cd tools/clang && git fetch) # Get matching revisions of both trees.
% git checkout master
git checkout master &&
git svn rebase -l)
+Likewise for compiler-rt and test-suite.
+
This leaves your working directories on their master branches, so you'll need to
``checkout`` each working branch individually and ``rebase`` it on top of its
-parent branch. (Note: This script is intended for relative newbies to git. If
-you have more experience, you can likely improve on it.)
+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
+
+ STATUS=$(git status -s | grep -v "??")
+
+ if [ ! -z "$STATUS" ]; then
+ STASH="yes"
+ git stash >/dev/null
+ fi
+
+ 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``:
+
+.. code-block:: console
+
+ % git svn dcommit
+
+Note that git-svn will create one SVN commit for each Git commit you have pending,
+so squash and edit each commit before executing ``dcommit`` to make sure they all
+conform to the coding standards and the developers' policy.
+
+On success, ``dcommit`` will rebase against the HEAD of SVN, so to avoid conflict,
+please make sure your current branch is up-to-date (via fetch/rebase) before
+proceeding.
The git-svn metadata can get out of sync after you mess around with branches and
``dcommit``. When that happens, ``git svn dcommit`` stops working, complaining
about files with uncommitted changes. The fix is to rebuild the metadata:
-.. code-block:: bash
+.. code-block:: console
% rm -rf .git/svn
% git svn rebase -l
+Please, refer to the Git-SVN manual (``man git-svn``) for more information.
+
Local LLVM Configuration
------------------------
| Variable | Purpose |
+============+===========================================================+
| CC | Tells ``configure`` which C compiler to use. By default, |
-| | ``configure`` will look for the first GCC C compiler in |
-| | ``PATH``. Use this variable to override ``configure``\'s |
-| | default behavior. |
+| | ``configure`` will check ``PATH`` for ``clang`` and GCC C |
+| | compilers (in this order). Use this variable to override |
+| | ``configure``\'s default behavior. |
+------------+-----------------------------------------------------------+
| CXX | Tells ``configure`` which C++ compiler to use. By |
-| | default, ``configure`` will look for the first GCC C++ |
-| | compiler in ``PATH``. Use this variable to override |
-| | ``configure``'s default behavior. |
+| | default, ``configure`` will check ``PATH`` for |
+| | ``clang++`` and GCC C++ compilers (in this order). Use |
+| | this variable to override ``configure``'s default |
+| | behavior. |
+------------+-----------------------------------------------------------+
The following options can be used to set or enable LLVM specific options:
#. Change directory into the object root directory:
- .. code-block:: bash
+ .. code-block:: console
% cd OBJ_ROOT
#. Run the ``configure`` script located in the LLVM source tree:
- .. code-block:: bash
+ .. code-block:: console
% SRC_ROOT/configure --prefix=/install/path [other options]
Once you have LLVM configured, you can build it by entering the *OBJ_ROOT*
directory and issuing the following command:
-.. code-block:: bash
+.. code-block:: console
% gmake
parallel build options provided by GNU Make. For example, you could use the
command:
-.. code-block:: bash
+.. code-block:: console
% gmake -j2
After following the instructions there for installing Sphinx, build the LLVM
HTML documentation by doing the following:
-.. code-block:: bash
+.. code-block:: console
$ cd SRC_ROOT/docs
$ make -f Makefile.sphinx
* Change directory to where the LLVM object files should live:
- .. code-block:: bash
+ .. code-block:: console
% cd OBJ_ROOT
* Run the ``configure`` script found in the LLVM source directory:
- .. code-block:: bash
+ .. code-block:: console
% SRC_ROOT/configure
----------------------------
If you're running on a Linux system that supports the `binfmt_misc
-<http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html>`_
+<http://en.wikipedia.org/wiki/binfmt_misc>`_
module, and you have root access on the system, you can set your system up to
execute LLVM bitcode files directly. To do this, use commands like this (the
first command may not be required if you are already using the module):
-.. code-block:: bash
+.. code-block:: console
% mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
% echo ':llvm:M::BC::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register
This allows you to execute LLVM bitcode files directly. On Debian, you can also
use this command instead of the 'echo' command above:
-.. code-block:: bash
+.. code-block:: console
% sudo update-binfmts --install llvm /path/to/lli --magic 'BC'
#. Next, compile the C file into a native executable:
- .. code-block:: bash
+ .. code-block:: console
% clang hello.c -o hello
#. Next, compile the C file into a LLVM bitcode file:
- .. code-block:: bash
+ .. code-block:: console
% clang -O3 -emit-llvm hello.c -c -o hello.bc
#. Run the program in both forms. To run the program, use:
- .. code-block:: bash
+ .. code-block:: console
% ./hello
and
- .. code-block:: bash
+ .. code-block:: console
% lli hello.bc
- The second examples shows how to invoke the LLVM JIT, `lli
- <CommandGuide/html/lli.html>`_.
+ The second examples shows how to invoke the LLVM JIT, :doc:`lli
+ <CommandGuide/lli>`.
#. Use the ``llvm-dis`` utility to take a look at the LLVM assembly code:
- .. code-block:: bash
+ .. code-block:: console
% llvm-dis < hello.bc | less
#. Compile the program to native assembly using the LLC code generator:
- .. code-block:: bash
+ .. code-block:: console
% llc hello.bc -o hello.s
#. Assemble the native assembly language file into a program:
- .. code-block:: bash
+ .. code-block:: console
- **Solaris:** % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
+ % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native # On Solaris
- **Others:** % gcc hello.s -o hello.native
+ % gcc hello.s -o hello.native # On others
#. Execute the native code program:
- .. code-block:: bash
+ .. code-block:: console
% ./hello.native
projects / oota-llvm.git / blobdiff