Updating GettingStarted documentation to reference CMake as the preferred way to build LLVM.

Reviewers: chandlerc, samsonov, echristo

Reviewed By: samsonov

Subscribers: emaste, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D8046

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232135 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Bieneman 2015-03-13 01:58:14 +00:00
parent 011cb4d5bd
commit 1bba7511b2
3 changed files with 453 additions and 203 deletions

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@ -0,0 +1,297 @@
====================================
Building LLVM With Autotools
====================================
.. contents::
:local:
Overview
========
Local LLVM Configuration
------------------------
Once checked out from the Subversion repository, the LLVM suite source code must
be configured via the ``configure`` script. This script sets variables in the
various ``*.in`` files, most notably ``llvm/Makefile.config`` and
``llvm/include/Config/config.h``. It also populates *OBJ_ROOT* with the
Makefiles needed to begin building LLVM.
The following environment variables are used by the ``configure`` script to
configure the build system:
+------------+-----------------------------------------------------------+
| Variable | Purpose |
+============+===========================================================+
| CC | Tells ``configure`` which C compiler to use. By default, |
| | ``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 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:
``--enable-optimized``
Enables optimized compilation (debugging symbols are removed and GCC
optimization flags are enabled). Note that this is the default setting if you
are using the LLVM distribution. The default behavior of a Subversion
checkout is to use an unoptimized build (also known as a debug build).
``--enable-debug-runtime``
Enables debug symbols in the runtime libraries. The default is to strip debug
symbols from the runtime libraries.
``--enable-jit``
Compile the Just In Time (JIT) compiler functionality. This is not available
on all platforms. The default is dependent on platform, so it is best to
explicitly enable it if you want it.
``--enable-targets=target-option``
Controls which targets will be built and linked into llc. The default value
for ``target_options`` is "all" which builds and links all available targets.
The "host" target is selected as the target of the build host. You can also
specify a comma separated list of target names that you want available in llc.
The target names use all lower case. The current set of targets is:
``aarch64, arm, arm64, cpp, hexagon, mips, mipsel, mips64, mips64el, msp430,
powerpc, nvptx, r600, sparc, systemz, x86, x86_64, xcore``.
``--enable-doxygen``
Look for the doxygen program and enable construction of doxygen based
documentation from the source code. This is disabled by default because
generating the documentation can take a long time and producess 100s of
megabytes of output.
To configure LLVM, follow these steps:
#. Change directory into the object root directory:
.. code-block:: console
% cd OBJ_ROOT
#. Run the ``configure`` script located in the LLVM source tree:
.. code-block:: console
% SRC_ROOT/configure --prefix=/install/path [other options]
Compiling the LLVM Suite Source Code
------------------------------------
Once you have configured LLVM, you can build it. There are three types of
builds:
Debug Builds
These builds are the default when one is using a Subversion checkout and
types ``gmake`` (unless the ``--enable-optimized`` option was used during
configuration). The build system will compile the tools and libraries with
debugging information. To get a Debug Build using the LLVM distribution the
``--disable-optimized`` option must be passed to ``configure``.
Release (Optimized) Builds
These builds are enabled with the ``--enable-optimized`` option to
``configure`` or by specifying ``ENABLE_OPTIMIZED=1`` on the ``gmake`` command
line. For these builds, the build system will compile the tools and libraries
with GCC optimizations enabled and strip debugging information from the
libraries and executables it generates. Note that Release Builds are default
when using an LLVM distribution.
Profile Builds
These builds are for use with profiling. They compile profiling information
into the code for use with programs like ``gprof``. Profile builds must be
started by specifying ``ENABLE_PROFILING=1`` on the ``gmake`` command line.
Once you have LLVM configured, you can build it by entering the *OBJ_ROOT*
directory and issuing the following command:
.. code-block:: console
% gmake
If the build fails, please `check here <GettingStarted.html#check-here>`_
to see if you are using a version of GCC that is known not to compile LLVM.
If you have multiple processors in your machine, you may wish to use some of the
parallel build options provided by GNU Make. For example, you could use the
command:
.. code-block:: console
% gmake -j2
There are several special targets which are useful when working with the LLVM
source code:
``gmake clean``
Removes all files generated by the build. This includes object files,
generated C/C++ files, libraries, and executables.
``gmake dist-clean``
Removes everything that ``gmake clean`` does, but also removes files generated
by ``configure``. It attempts to return the source tree to the original state
in which it was shipped.
``gmake install``
Installs LLVM header files, libraries, tools, and documentation in a hierarchy
under ``$PREFIX``, specified with ``./configure --prefix=[dir]``, which
defaults to ``/usr/local``.
``gmake -C runtime install-bytecode``
Assuming you built LLVM into $OBJDIR, when this command is run, it will
install bitcode libraries into the GCC front end's bitcode library directory.
If you need to update your bitcode libraries, this is the target to use once
you've built them.
Please see the `Makefile Guide <MakefileGuide.html>`_ for further details on
these ``make`` targets and descriptions of other targets available.
It is also possible to override default values from ``configure`` by declaring
variables on the command line. The following are some examples:
``gmake ENABLE_OPTIMIZED=1``
Perform a Release (Optimized) build.
``gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1``
Perform a Release (Optimized) build without assertions enabled.
``gmake ENABLE_OPTIMIZED=0``
Perform a Debug build.
``gmake ENABLE_PROFILING=1``
Perform a Profiling build.
``gmake VERBOSE=1``
Print what ``gmake`` is doing on standard output.
``gmake TOOL_VERBOSE=1``
Ask each tool invoked by the makefiles to print out what it is doing on
the standard output. This also implies ``VERBOSE=1``.
Every directory in the LLVM object tree includes a ``Makefile`` to build it and
any subdirectories that it contains. Entering any directory inside the LLVM
object tree and typing ``gmake`` should rebuild anything in or below that
directory that is out of date.
This does not apply to building the documentation.
LLVM's (non-Doxygen) documentation is produced with the
`Sphinx <http://sphinx-doc.org/>`_ documentation generation system.
There are some HTML documents that have not yet been converted to the new
system (which uses the easy-to-read and easy-to-write
`reStructuredText <http://sphinx-doc.org/rest.html>`_ plaintext markup
language).
The generated documentation is built in the ``SRC_ROOT/docs`` directory using
a special makefile.
For instructions on how to install Sphinx, see
`Sphinx Introduction for LLVM Developers
<http://lld.llvm.org/sphinx_intro.html>`_.
After following the instructions there for installing Sphinx, build the LLVM
HTML documentation by doing the following:
.. code-block:: console
$ cd SRC_ROOT/docs
$ make -f Makefile.sphinx
This creates a ``_build/html`` sub-directory with all of the HTML files, not
just the generated ones.
This directory corresponds to ``llvm.org/docs``.
For example, ``_build/html/SphinxQuickstartTemplate.html`` corresponds to
``llvm.org/docs/SphinxQuickstartTemplate.html``.
The :doc:`SphinxQuickstartTemplate` is useful when creating a new document.
Cross-Compiling LLVM
--------------------
It is possible to cross-compile LLVM itself. That is, you can create LLVM
executables and libraries to be hosted on a platform different from the platform
where they are built (a Canadian Cross build). To configure a cross-compile,
supply the configure script with ``--build`` and ``--host`` options that are
different. The values of these options must be legal target triples that your
GCC compiler supports.
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
---------------------------------
The LLVM build system is capable of sharing a single LLVM source tree among
several LLVM builds. Hence, it is possible to build LLVM for several different
platforms or configurations using the same source tree.
This is accomplished in the typical autoconf manner:
* Change directory to where the LLVM object files should live:
.. code-block:: console
% cd OBJ_ROOT
* Run the ``configure`` script found in the LLVM source directory:
.. code-block:: console
% SRC_ROOT/configure
The LLVM build will place files underneath *OBJ_ROOT* in directories named after
the build type:
Debug Builds with assertions enabled (the default)
Tools
``OBJ_ROOT/Debug+Asserts/bin``
Libraries
``OBJ_ROOT/Debug+Asserts/lib``
Release Builds
Tools
``OBJ_ROOT/Release/bin``
Libraries
``OBJ_ROOT/Release/lib``
Profile Builds
Tools
``OBJ_ROOT/Profile/bin``
Libraries
``OBJ_ROOT/Profile/lib``

View File

@ -61,7 +61,37 @@ Here's the short story for getting up and running quickly with LLVM:
* ``cd llvm/projects``
* ``svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite``
#. Configure and build LLVM and Clang:
#. Configure and build LLVM and Clang (Recommended process using CMake):
* ``cd where you want to build llvm``
* ``mkdir build``
* ``cd build``
* ``cmake -G <generator> [options] <path to llvm sources>``
Some common generators are:
* ``Unix Makefiles`` --- for generating make-compatible parallel makefiles.
* ``Ninja`` --- for generating `Ninja <http://martine.github.io/ninja/>`
build files.
* ``Visual Studio`` --- for generating Visual Studio projects and
solutions.
* ``Xcode`` --- for generating Xcode projects.
Some Common options:
* ``-DCMAKE_INSTALL_PREFIX=directory`` --- Specify for *directory* the full
pathname of where you want the LLVM tools and libraries to be installed
(default ``/usr/local``).
* ``-DCMAKE_BUILD_TYPE=type`` --- Valid options for *type* are Debug,
Release, RelWithDebInfo, and MinSizeRel. Default is Debug.
* ``-DLLVM_ENABLE_ASSERTIONS=On`` --- Compile with assertion checks enabled
(default is Yes for Debug builds, No for all other build types).
* For more information see `CMake <CMake.html>`_
#. Configure and build LLVM and Clang (Alternate process using configure):
* ``cd where-you-want-to-build-llvm``
* ``mkdir build`` (for building without polluting the source dir)
@ -87,11 +117,6 @@ Here's the short story for getting up and running quickly with LLVM:
* ``make check-all`` --- This run the regression tests to ensure everything
is in working order.
* It is also possible to use `CMake <CMake.html>`_ 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.
* If you get an "internal compiler error (ICE)" or test failures, see
`below`.
@ -134,7 +159,8 @@ Windows x64 x86-64 Visual Studio
#. Code generation supported for Pentium processors and up
#. Code generation supported for 32-bit ABI only
#. To use LLVM modules on Win32-based system, you may configure LLVM
with ``--enable-shared``.
with ``-DBUILD_SHARED_LIBS=On`` for CMake builds or ``--enable-shared``
for configure builds.
#. 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
@ -435,7 +461,7 @@ follows:
* ``cd where-you-want-llvm-to-live``
* Read-Only: ``svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm``
* Read-Write:``svn co https://user@llvm.org/svn/llvm-project/llvm/trunk llvm``
* Read-Write: ``svn co https://user@llvm.org/svn/llvm-project/llvm/trunk llvm``
This will create an '``llvm``' directory in the current directory and fully
populate it with the LLVM source code, Makefiles, test directories, and local
@ -664,66 +690,61 @@ Local LLVM Configuration
------------------------
Once checked out from the Subversion repository, the LLVM suite source code must
be configured via the ``configure`` script. This script sets variables in the
various ``*.in`` files, most notably ``llvm/Makefile.config`` and
``llvm/include/Config/config.h``. It also populates *OBJ_ROOT* with the
Makefiles needed to begin building LLVM.
be configured before being built. For instructions using autotools please see
`Building LLVM With Autotools <BuildingLLVMWithAutotools.html>`_. The
recommended process uses CMake. Unlinke the normal ``configure`` script, CMake
generates the build files in whatever format you request as well as various
``*.inc`` files, and ``llvm/include/Config/config.h``.
The following environment variables are used by the ``configure`` script to
configure the build system:
Variables are passed to ``cmake`` on the command line using the format
``-D<variable name>=<value>``. The following variables are some common options
used by people developing LLVM.
+------------+-----------------------------------------------------------+
| Variable | Purpose |
+============+===========================================================+
| CC | Tells ``configure`` which C compiler to use. By default, |
| | ``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 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:
``--enable-optimized``
Enables optimized compilation (debugging symbols are removed and GCC
optimization flags are enabled). Note that this is the default setting if you
are using the LLVM distribution. The default behavior of a Subversion
checkout is to use an unoptimized build (also known as a debug build).
``--enable-debug-runtime``
Enables debug symbols in the runtime libraries. The default is to strip debug
symbols from the runtime libraries.
``--enable-jit``
Compile the Just In Time (JIT) compiler functionality. This is not available
on all platforms. The default is dependent on platform, so it is best to
explicitly enable it if you want it.
``--enable-targets=target-option``
Controls which targets will be built and linked into llc. The default value
for ``target_options`` is "all" which builds and links all available targets.
The "host" target is selected as the target of the build host. You can also
specify a comma separated list of target names that you want available in llc.
The target names use all lower case. The current set of targets is:
``aarch64, arm, arm64, cpp, hexagon, mips, mipsel, mips64, mips64el, msp430,
powerpc, nvptx, r600, sparc, systemz, x86, x86_64, xcore``.
``--enable-doxygen``
Look for the doxygen program and enable construction of doxygen based
documentation from the source code. This is disabled by default because
generating the documentation can take a long time and producess 100s of
megabytes of output.
+-------------------------+----------------------------------------------------+
| Variable | Purpose |
+=========================+====================================================+
| CMAKE_C_COMPILER | Tells ``cmake`` which C compiler to use. By |
| | default, this will be /usr/bin/cc. |
+-------------------------+----------------------------------------------------+
| CMAKE_CXX_COMPILER | Tells ``cmake`` which C++ compiler to use. By |
| | default, this will be /usr/bin/c++. |
+-------------------------+----------------------------------------------------+
| CMAKE_BUILD_TYPE | Tells ``cmake`` what type of build you are trying |
| | to generate files for. Valid options are Debug, |
| | Release, RelWithDebInfo, and MinSizeRel. Default |
| | is Debug. |
+-------------------------+----------------------------------------------------+
| CMAKE_INSTALL_PREFIX | Specifies the install directory to target when |
| | running the install action of the build files. |
+-------------------------+----------------------------------------------------+
| LLVM_TARGETS_TO_BUILD | A semicolon delimited list controlling which |
| | targets will be built and linked into llc. This is |
| | equivalent to the ``--enable-targets`` option in |
| | the configure script. The default list is defined |
| | as ``LLVM_ALL_TARGETS``, and can be set to include |
| | out-of-tree targets. The default value includes: |
| | ``AArch64, ARM, CppBackend, Hexagon, |
| | Mips, MSP430, NVPTX, PowerPC, R600, Sparc, |
| | SystemZ, X86, XCore``. |
+-------------------------+----------------------------------------------------+
| LLVM_ENABLE_DOXYGEN | Build doxygen-based documentation from the source |
| | code This is disabled by default because it is |
| | slow and generates a lot of output. |
+-------------------------+----------------------------------------------------+
| LLVM_ENABLE_SPHINX | Build sphinx-based documentation from the source |
| | code. This is disabled by default because it is |
| | slow and generates a lot of output. |
+-------------------------+----------------------------------------------------+
| LLVM_BUILD_LLVM_DYLIB | Generate libLLVM.so. This library contains a |
| | default set of LLVM components that can be |
| | overridden with ``LLVM_DYLIB_COMPONENTS``. The |
| | default contains most of LLVM and is defined in |
| | ``tools/llvm-shlib/CMakelists.txt``. |
+-------------------------+----------------------------------------------------+
| LLVM_OPTIMIZED_TABLEGEN | Builds a release tablegen that gets used during |
| | the LLVM build. This can dramatically speed up |
| | debug builds. |
+-------------------------+----------------------------------------------------+
To configure LLVM, follow these steps:
@ -733,47 +754,52 @@ To configure LLVM, follow these steps:
% cd OBJ_ROOT
#. Run the ``configure`` script located in the LLVM source tree:
#. Run the ``cmake``:
.. code-block:: console
% SRC_ROOT/configure --prefix=/install/path [other options]
% cmake -G "Unix Makefiles" -DCMAKE_INSTALL_PREFIX=prefix=/install/path
[other options] SRC_ROOT
Compiling the LLVM Suite Source Code
------------------------------------
Once you have configured LLVM, you can build it. There are three types of
builds:
Unlike with autotools, with CMake your build type is defined at configuration.
If you want to change your build type, you can re-run cmake with the following
invocation:
Debug Builds
.. code-block:: console
These builds are the default when one is using a Subversion checkout and
types ``gmake`` (unless the ``--enable-optimized`` option was used during
configuration). The build system will compile the tools and libraries with
debugging information. To get a Debug Build using the LLVM distribution the
``--disable-optimized`` option must be passed to ``configure``.
% cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=type SRC_ROOT
Release (Optimized) Builds
Between runs, CMake preserves the values set for all options. CMake has the
following build types defined:
These builds are enabled with the ``--enable-optimized`` option to
``configure`` or by specifying ``ENABLE_OPTIMIZED=1`` on the ``gmake`` command
line. For these builds, the build system will compile the tools and libraries
with GCC optimizations enabled and strip debugging information from the
libraries and executables it generates. Note that Release Builds are default
when using an LLVM distribution.
Debug
Profile Builds
These builds are the default. The build system will compile the tools and
libraries unoptimized, with debugging information, and asserts enabled.
These builds are for use with profiling. They compile profiling information
into the code for use with programs like ``gprof``. Profile builds must be
started by specifying ``ENABLE_PROFILING=1`` on the ``gmake`` command line.
Release
For these builds, the build system will compile the tools and libraries
with optimizations enabled and not generate debug info. CMakes default
optimization level is -O3. This can be configured by setting the
``CMAKE_CXX_FLAGS_RELEASE`` variable on the CMake command line.
RelWithDebInfo
These builds are useful when debugging. They generate optimized binaries with
debug information. CMakes default optimization level is -O2. This can be
configured by setting the ``CMAKE_CXX_FLAGS_RELWITHDEBINFO`` variable on the
CMake command line.
Once you have LLVM configured, you can build it by entering the *OBJ_ROOT*
directory and issuing the following command:
.. code-block:: console
% gmake
% make
If the build fails, please `check here`_ to see if you are using a version of
GCC that is known not to compile LLVM.
@ -784,110 +810,51 @@ command:
.. code-block:: console
% gmake -j2
% make -j2
There are several special targets which are useful when working with the LLVM
source code:
``gmake clean``
``make clean``
Removes all files generated by the build. This includes object files,
generated C/C++ files, libraries, and executables.
``gmake dist-clean``
Removes everything that ``gmake clean`` does, but also removes files generated
by ``configure``. It attempts to return the source tree to the original state
in which it was shipped.
``gmake install``
``make install``
Installs LLVM header files, libraries, tools, and documentation in a hierarchy
under ``$PREFIX``, specified with ``./configure --prefix=[dir]``, which
under ``$PREFIX``, specified with ``CMAKE_INSTALL_PREFIX``, which
defaults to ``/usr/local``.
``gmake -C runtime install-bytecode``
``make docs-llvm-html``
Assuming you built LLVM into $OBJDIR, when this command is run, it will
install bitcode libraries into the GCC front end's bitcode library directory.
If you need to update your bitcode libraries, this is the target to use once
you've built them.
Please see the `Makefile Guide <MakefileGuide.html>`_ for further details on
these ``make`` targets and descriptions of other targets available.
It is also possible to override default values from ``configure`` by declaring
variables on the command line. The following are some examples:
``gmake ENABLE_OPTIMIZED=1``
Perform a Release (Optimized) build.
``gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1``
Perform a Release (Optimized) build without assertions enabled.
``gmake ENABLE_OPTIMIZED=0``
Perform a Debug build.
``gmake ENABLE_PROFILING=1``
Perform a Profiling build.
``gmake VERBOSE=1``
Print what ``gmake`` is doing on standard output.
``gmake TOOL_VERBOSE=1``
Ask each tool invoked by the makefiles to print out what it is doing on
the standard output. This also implies ``VERBOSE=1``.
Every directory in the LLVM object tree includes a ``Makefile`` to build it and
any subdirectories that it contains. Entering any directory inside the LLVM
object tree and typing ``gmake`` should rebuild anything in or below that
directory that is out of date.
This does not apply to building the documentation.
LLVM's (non-Doxygen) documentation is produced with the
`Sphinx <http://sphinx-doc.org/>`_ documentation generation system.
There are some HTML documents that have not yet been converted to the new
system (which uses the easy-to-read and easy-to-write
`reStructuredText <http://sphinx-doc.org/rest.html>`_ plaintext markup
language).
The generated documentation is built in the ``SRC_ROOT/docs`` directory using
a special makefile.
For instructions on how to install Sphinx, see
`Sphinx Introduction for LLVM Developers
<http://lld.llvm.org/sphinx_intro.html>`_.
After following the instructions there for installing Sphinx, build the LLVM
HTML documentation by doing the following:
.. code-block:: console
$ cd SRC_ROOT/docs
$ make -f Makefile.sphinx
This creates a ``_build/html`` sub-directory with all of the HTML files, not
just the generated ones.
This directory corresponds to ``llvm.org/docs``.
For example, ``_build/html/SphinxQuickstartTemplate.html`` corresponds to
``llvm.org/docs/SphinxQuickstartTemplate.html``.
The :doc:`SphinxQuickstartTemplate` is useful when creating a new document.
If configured with ``-DLLVM_ENABLE_SPHINX=On``, this will generate a directory
at ``OBJ_ROOT/docs/html`` which contains the HTML formatted documentation.
Cross-Compiling LLVM
--------------------
It is possible to cross-compile LLVM itself. That is, you can create LLVM
executables and libraries to be hosted on a platform different from the platform
where they are built (a Canadian Cross build). To configure a cross-compile,
supply the configure script with ``--build`` and ``--host`` options that are
different. The values of these options must be legal target triples that your
GCC compiler supports.
where they are built (a Canadian Cross build). To generate build files for
cross-compiling CMake provides a variable ``CMAKE_TOOLCHAIN_FILE`` which can
define compiler flags and variables used during the CMake test operations.
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).
host but can be executed on the target. As an example the following CMake
invocation can generate build files targeting iOS. This will work on Mac OS X
with the latest Xcode:
.. code-block:: console
% cmake -G "Ninja" -DCMAKE_OSX_ARCHITECTURES=“armv7;armv7s;arm64"
-DCMAKE_TOOLCHAIN_FILE=<PATH_TO_LLVM>/cmake/platforms/iOS.cmake
-DCMAKE_BUILD_TYPE=Release -DLLVM_BUILD_RUNTIME=Off -DLLVM_INCLUDE_TESTS=Off
-DLLVM_INCLUDE_EXAMPLES=Off -DLLVM_ENABLE_BACKTRACES=Off [options]
<PATH_TO_LLVM>
Note: There are some additional flags that need to be passed when building for
iOS due to limitations in the iOS SDK.
Check :doc:`HowToCrossCompileLLVM` and `Clang docs on how to cross-compile in general
<http://clang.llvm.org/docs/CrossCompilation.html>`_ for more information
@ -908,44 +875,25 @@ This is accomplished in the typical autoconf manner:
% cd OBJ_ROOT
* Run the ``configure`` script found in the LLVM source directory:
* Run ``cmake``:
.. code-block:: console
% SRC_ROOT/configure
% cmake -G "Unix Makefiles" SRC_ROOT
The LLVM build will place files underneath *OBJ_ROOT* in directories named after
the build type:
The LLVM build will create a structure underneath *OBJ_ROOT* that matches the
LLVM source tree. At each level where source files are present in the source
tree there will be a corresponding ``CMakeFiles`` directory in the *OBJ_ROOT*.
Underneath that directory there is another directory with a name ending in
``.dir`` under which you'll find object files for each source.
Debug Builds with assertions enabled (the default)
For example:
Tools
``OBJ_ROOT/Debug+Asserts/bin``
Libraries
``OBJ_ROOT/Debug+Asserts/lib``
Release Builds
Tools
``OBJ_ROOT/Release/bin``
Libraries
``OBJ_ROOT/Release/lib``
Profile Builds
Tools
``OBJ_ROOT/Profile/bin``
Libraries
``OBJ_ROOT/Profile/lib``
.. code-block:: console
% cd llvm_build_dir
% find lib/Support/ -name APFloat*
lib/Support/CMakeFiles/LLVMSupport.dir/APFloat.cpp.o
Optional Configuration Items
----------------------------

View File

@ -70,6 +70,7 @@ representation.
CommandGuide/index
GettingStarted
GettingStartedVS
BuildingLLVMWithAutotools
FAQ
Lexicon
HowToAddABuilder
@ -105,6 +106,10 @@ representation.
An addendum to the main Getting Started guide for those using Visual Studio
on Windows.
:doc:`BuildingLLVMWithAutotools`
An addendum to the Getting Started guide with instructions for building LLVM
with the Autotools build system.
:doc:`tutorial/index`
Tutorials about using LLVM. Includes a tutorial about making a custom
language with LLVM.