Unify build documentation and convert to reStructuredText

We now have several options that apply for both libraries and they
shouldn't be documented in multiple files. When already merging
the two Build_With_CMake.txt documents, convert them to
reStructuredText which is used for all of LLVM's documentation.

Differential Revision: https://reviews.llvm.org/D40920

llvm-svn: 321481

openmp/CMakeLists.txt

@@ -17,7 +17,7 @@ if (OPENMP_STANDALONE_BUILD OR "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_S
   set(OPENMP_ENABLE_WERROR FALSE CACHE BOOL
     "Enable -Werror flags to turn warnings into errors for supporting compilers.")
   set(OPENMP_LIBDIR_SUFFIX "" CACHE STRING
-    "suffix of lib installation directory, e.g. 64 => lib64")
+    "Suffix of lib installation directory, e.g. 64 => lib64")
 
   # Group test settings.
   set(OPENMP_TEST_C_COMPILER ${CMAKE_C_COMPILER} CACHE STRING

openmp/README.rst

@@ -0,0 +1,304 @@
+========================================
+How to Build the LLVM* OpenMP* Libraries
+========================================
+This repository requires `CMake <http://www.cmake.org/>`_ v2.8.0 or later.  LLVM
+and Clang need a more recent version which also applies for in-tree builds.  For
+more information than available in this document please see
+`LLVM's CMake documentation <http://llvm.org/docs/CMake.html>`_ and the
+`official documentation <https://cmake.org/cmake/help/v2.8.0/cmake.html>`_.
+
+.. contents::
+   :local:
+
+How to Call CMake Initially, then Repeatedly
+============================================
+- When calling CMake for the first time, all needed compiler options must be
+  specified on the command line.  After this initial call to CMake, the compiler
+  definitions must not be included for further calls to CMake.  Other options
+  can be specified on the command line multiple times including all definitions
+  in the build options section below.
+- Example of configuring, building, reconfiguring, rebuilding:
+
+  .. code-block:: console
+
+    $ mkdir build
+    $ cd build
+    $ cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ..  # Initial configuration
+    $ make
+    ...
+    $ make clean
+    $ cmake -DCMAKE_BUILD_TYPE=Debug ..                               # Second configuration
+    $ make
+    ...
+    $ rm -rf *
+    $ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ ..        # Third configuration
+    $ make
+
+- Notice in the example how the compiler definitions are only specified for an
+  empty build directory, but other build options are used at any time.
+- The file ``CMakeCache.txt`` which is created after the first call to CMake is
+  a configuration file which holds all values for the build options.  These
+  values can be changed using a text editor to modify ``CMakeCache.txt`` as
+  opposed to using definitions on the command line.
+- To have CMake create a particular type of build generator file simply include
+  the ``-G <Generator name>`` option:
+
+  .. code-block:: console
+
+    $ cmake -G "Unix Makefiles" ...
+
+  You can see a list of generators CMake supports by executing the cmake command
+  with no arguments.
+
+Instructions to Build
+=====================
+.. code-block:: console
+
+ $ cd openmp_top_level/ [ this directory with libomptarget/, runtime/, etc. ]
+ $ mkdir build
+ $ cd build
+
+ [ Unix* Libraries ]
+ $ cmake -DCMAKE_C_COMPILER=<C Compiler> -DCMAKE_CXX_COMPILER=<C++ Compiler> ..
+
+ [ Windows* Libraries ]
+ $ cmake -G <Generator Type> -DCMAKE_C_COMPILER=<C Compiler> -DCMAKE_CXX_COMPILER=<C++ Compiler> -DCMAKE_ASM_MASM_COMPILER=[ml | ml64] -DCMAKE_BUILD_TYPE=Release ..
+
+ $ make
+ $ make install
+
+CMake Options
+=============
+Builds with CMake can be customized by means of options as already seen above.
+One possibility is to pass them via the command line:
+
+.. code-block:: console
+
+  $ cmake -DOPTION=<value> path/to/source
+
+.. note:: The first value listed is the respective default for that option.
+
+Generic Options
+---------------
+For full documentation consult the CMake manual or execute
+``cmake --help-variable VARIABLE_NAME`` to get information about a specific
+variable.
+
+**CMAKE_BUILD_TYPE** = ``Release|Debug|RelWithDebInfo``
+  Build type can be ``Release``, ``Debug``, or ``RelWithDebInfo`` which chooses
+  the optimization level and presence of debugging symbols.
+
+**CMAKE_C_COMPILER** = <C compiler name>
+  Specify the C compiler.
+
+**CMAKE_CXX_COMPILER** = <C++ compiler name>
+  Specify the C++ compiler.
+
+**CMAKE_Fortran_COMPILER** = <Fortran compiler name>
+  Specify the Fortran compiler. This option is only needed when
+  **LIBOMP_FORTRAN_MODULES** is ``ON`` (see below).  So typically, a Fortran
+  compiler is not needed during the build.
+
+**CMAKE_ASM_MASM_COMPILER** = ``ml|ml64``
+  This option is only relevant for Windows*.
+
+Options for all Libraries
+-------------------------
+
+**OPENMP_ENABLE_WERROR** = ``OFF|ON``
+  Treat warnings as errors and fail, if a compiler warning is triggered.
+
+**OPENMP_LIBDIR_SUFFIX** = ``""``
+  Extra suffix to append to the directory where libraries are to be installed.
+
+**OPENMP_TEST_C_COMPILER** = ``${CMAKE_C_COMPILER}``
+  Compiler to use for testing. Defaults to the compiler that was also used for
+  building.
+
+**OPENMP_TEST_CXX_COMPILER** = ``${CMAKE_CXX_COMPILER}``
+  Compiler to use for testing. Defaults to the compiler that was also used for
+  building.
+
+**OPENMP_LLVM_TOOLS_DIR** = ``/path/to/built/llvm/tools``
+  Additional path to search for LLVM tools needed by tests.
+
+**OPENMP_LLVM_LIT_EXECUTABLE** = ``/path/to/llvm-lit``
+  Specify full path to ``llvm-lit`` executable for running tests.  The default
+  is to search the ``PATH`` and the directory in **OPENMP_LLVM_TOOLS_DIR**.
+
+**OPENMP_FILECHECK_EXECUTABLE** = ``/path/to/FileCheck``
+  Specify full path to ``FileCheck`` executable for running tests.  The default
+  is to search the ``PATH`` and the directory in **OPENMP_LLVM_TOOLS_DIR**.
+
+Options for ``libomp``
+----------------------
+
+**LIBOMP_ARCH** = ``aarch64|arm|i386|mic|mips|mips64|ppc64|ppc64le|x86_64``
+  The default value for this option is chosen based on probing the compiler for
+  architecture macros (e.g., is ``__x86_64__`` predefined by compiler?).
+
+**LIBOMP_MIC_ARCH** = ``knc|knf``
+  Intel(R) Many Integrated Core Architecture (Intel(R) MIC Architecture) to
+  build for.  This value is ignored if **LIBOMP_ARCH** does not equal ``mic``.
+
+**LIBOMP_OMP_VERSION** = ``50|45|40|30``
+  OpenMP version to build for.  Older versions will disable certain
+  functionality and entry points.
+
+**LIBOMP_LIB_TYPE** = ``normal|profile|stubs``
+  Library type can be ``normal``, ``profile``, or ``stubs``.
+
+**LIBOMP_USE_VERSION_SYMBOLS** = ``ON|OFF``
+  Use versioned symbols for building the library.  This option only makes sense
+  for ELF based libraries where version symbols are supported (Linux*, some BSD*
+  variants).  It is ``OFF`` by default for Windows* and macOS*, but ``ON`` for
+  other Unix based operating systems.
+
+**LIBOMP_ENABLE_SHARED** = ``ON|OFF``
+  Build a shared library.  If this option is ``OFF``, static OpenMP libraries
+  will be built instead of dynamic ones.
+
+  .. note::
+
+    Static libraries are not supported on Windows*.
+
+**LIBOMP_FORTRAN_MODULES** = ``OFF|ON``
+  Create the Fortran modules (requires Fortran compiler).
+
+macOS* Fat Libraries
+""""""""""""""""""
+On macOS* machines, it is possible to build universal (or fat) libraries which
+include both i386 and x86_64 architecture objects in a single archive.
+
+.. code-block:: console
+
+  $ cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_OSX_ARCHITECTURES='i386;x86_64' ..
+  $ make
+
+There is also an option **LIBOMP_OSX_ARCHITECTURES** which can be set in case
+this is an LLVM source tree build. It will only apply for the ``libomp`` library
+avoids having the entire LLVM/Clang build produce universal binaries.
+
+Optional Features
+"""""""""""""""""
+
+**LIBOMP_USE_ADAPTIVE_LOCKS** = ``ON|OFF``
+  Include adaptive locks, based on Intel(R) Transactional Synchronization
+  Extensions (Intel(R) TSX).  This feature is x86 specific and turned ``ON``
+  by default for IA-32 architecture and Intel(R) 64 architecture.
+
+**LIBOMP_USE_INTERNODE_ALIGNMENT** = ``OFF|ON``
+  Align certain data structures on 4096-byte.  This option is useful on
+  multi-node systems where a small ``CACHE_LINE`` setting leads to false sharing.
+
+**LIBOMP_OMPT_SUPPORT** = ``OFF|ON``
+  Include support for the OpenMP Tools Interface (OMPT).
+
+**LIBOMP_OMPT_OPTIONAL** = ``ON|OFF``
+  Include support for optional OMPT functionality.  This option is ignored if
+  **LIBOMP_OMPT_SUPPORT** is ``OFF``.
+
+**LIBOMP_STATS** = ``OFF|ON``
+  Include stats-gathering code.
+
+**LIBOMP_USE_DEBUGGER** = ``OFF|ON``
+  Include the friendly debugger interface.
+
+**LIBOMP_USE_HWLOC** = ``OFF|ON``
+  Use `OpenMPI's hwloc library <https://www.open-mpi.org/projects/hwloc/>`_ for
+  topology detection and affinity.
+
+**LIBOMP_HWLOC_INSTALL_DIR** = ``/path/to/hwloc/install/dir``
+  Specify install location of hwloc.  The configuration system will look for
+  ``hwloc.h`` in ``${LIBOMP_HWLOC_INSTALL_DIR}/include`` and the library in
+  ``${LIBOMP_HWLOC_INSTALL_DIR}/lib``.  The default is ``/usr/local``.
+  This option is only used if **LIBOMP_USE_HWLOC** is ``ON``.
+
+Additional Compiler Flags
+"""""""""""""""""""""""""
+
+These flags are **appended**, they do not overwrite any of the preset flags.
+
+**LIBOMP_CPPFLAGS** = <space-separated flags>
+  Additional C preprocessor flags.
+
+**LIBOMP_CFLAGS** = <space-separated flags>
+  Additional C compiler flags.
+
+**LIBOMP_CXXFLAGS** = <space-separated flags>
+  Additional C++ compiler flags.
+
+**LIBOMP_ASMFLAGS** = <space-separated flags>
+  Additional assembler flags.
+
+**LIBOMP_LDFLAGS** = <space-separated flags>
+  Additional linker flags.
+
+**LIBOMP_LIBFLAGS** = <space-separated flags>
+  Additional libraries to link.
+
+**LIBOMP_FFLAGS** = <space-separated flags>
+  Additional Fortran compiler flags.
+
+Options for ``libomptarget``
+----------------------------
+
+**LIBOMPTARGET_OPENMP_HEADER_FOLDER** = ``""``
+  Path of the folder that contains ``omp.h``.  This is required for testing
+  out-of-tree builds.
+
+**LIBOMPTARGET_OPENMP_HOST_RTL_FOLDER** = ``""``
+  Path of the folder that contains ``libomp.so``.  This is required for testing
+  out-of-tree builds.
+
+Example Usages of CMake
+=======================
+
+Typical Invocations
+-------------------
+
+.. code-block:: console
+
+  $ cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ..
+  $ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ ..
+  $ cmake -DCMAKE_C_COMPILER=icc -DCMAKE_CXX_COMPILER=icpc ..
+
+Advanced Builds with Various Options
+------------------------------------
+
+- Build the i386 Linux* library using GCC*
+
+  .. code-block:: console
+
+    $ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DLIBOMP_ARCH=i386 ..
+
+- Build the x86_64 debug Mac library using Clang*
+
+  .. code-block:: console
+
+    $ cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DLIBOMP_ARCH=x86_64 -DCMAKE_BUILD_TYPE=Debug ..
+
+- Build the library (architecture determined by probing compiler) using the
+  Intel(R) C Compiler and the Intel(R) C++ Compiler.  Also, create Fortran
+  modules with the Intel(R) Fortran Compiler.
+
+  .. code-block:: console
+
+    $ cmake -DCMAKE_C_COMPILER=icc -DCMAKE_CXX_COMPILER=icpc -DCMAKE_Fortran_COMPILER=ifort -DLIBOMP_FORTRAN_MODULES=on ..
+
+- Have CMake find the C/C++ compiler and specify additional flags for the C
+  compiler, preprocessor, and C++ compiler.
+
+  .. code-blocks:: console
+
+    $ cmake -DLIBOMP_CFLAGS='-specific-flag' -DLIBOMP_CPPFLAGS='-DNEW_FEATURE=1 -DOLD_FEATURE=0' -DLIBOMP_CXXFLAGS='--one-specific-flag --two-specific-flag' ..
+
+- Build the stubs library
+
+  .. code-blocks:: console
+
+    $ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DLIBOMP_LIB_TYPE=stubs ..
+
+**Footnotes**
+
+.. [*] Other names and brands may be claimed as the property of others.