[CMake] Disallow direct configuration

[Hahnfeld]

Summary

As a first step, this allows us to generalize the detection of
standalone builds and make it fully compatible when building in
llvm/runtimes/ which automatically sets OPENMP_STANDLONE_BUILD.

[pirama]

CMakeLists.txt

2 ↗

(On Diff #123030)

There should be a project() declaration here. If not, CMake adds an empty project() at the top of the file. This breaks the Android build because the setting of the CMP0056 policy via a CMake variable is not obeyed in this case. CMP0056 is needed to correctly configure cross-compile and linking for Android.

[Hahnfeld]

CMakeLists.txt

2 ↗

(On Diff #123030)

So you're currently configuring runtime/ directly which has a project()?

[pirama]

CMakeLists.txt

2 ↗

(On Diff #123030)

Yes.

[pirama]

CMakeLists.txt

1 ↗

(On Diff #123030)

Also, can we bump this up if there are no other issues? The other LLVM projects are all currently using 3.4.3.

[Hahnfeld]

CMakeLists.txt

1 ↗

(On Diff #123030)

Does that have any benefits? The LLVM requirement was bumped to use new features which I haven't come across yet in the openmp repository. So I'm somewhat reluctant as CMake 2.8 is still the default on CentOS, for example

[pirama]

CMakeLists.txt

1 ↗

(On Diff #123030)

CMake 3.4.3 defaults to the NEW behavior of CMP0056. That's the only benefit for us, but it's easy enough to work around. I don't know of any other major benefits there might be.

[Hahnfeld]

CMakeLists.txt

1 ↗

(On Diff #123030)

IMO that's not enough to upgrade. If you need that policy, you should submit a patch to enable that one explicitly.

[pirama]

CMakeLists.txt

1 ↗

(On Diff #123030)

I agree. I'll upload a patch once this current set of changes get submitted.

[Hahnfeld]

Add project() to top-level CMakeLists.txt

[Hahnfeld]

Rebase onto recent changes.

[Hahnfeld]

More comments on this patch (series)?

[jlpeyton]

CMakeLists.txt

15–17 ↗

(On Diff #123995)

If it is possible, we should have an OPENMP_ENABLE_RUNTIME option so people can prevent building the runtime/ subdirectory and only build the libomptarget/ directory. Does libomptarget rely on libomp?

[jlpeyton]

libomptarget/Build_With_CMake.txt

46–62 ↗

(On Diff #123995)

I think libomptarget/Build_With_CMake.txt and runtime/Build_WIth_CMake.txt should be unified and moved into openmp/Build_With_CMake.txt.

[grokos]

CMakeLists.txt

15–17 ↗

(On Diff #123995)

Yes, it does. It needs functions omp_get_default_device() and __kmpc_omp_taskwait(void *loc_ref, int32_t gtid). More functions may be added to the list of dependencies in the future.

[Hahnfeld]

CMakeLists.txt

15–17 ↗

(On Diff #123995)

Yes, we could but my viewpoint was that there is no OpenMP with at least the host runtime.

libomptarget/Build_With_CMake.txt

46–62 ↗

(On Diff #123995)

Yes, it definitely should. I wanted to tackle this after the renaming of the test settings so that I can put together the file once with the final options.

[jlpeyton]

Ok sounds good. LGTM.

openmp/trunk/CMakeLists.txt

 cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
 
-set(OPENMP_LLVM_TOOLS_DIR "" CACHE PATH "Path to LLVM tools for testing")
+# llvm/runtimes/ will set OPENMP_STANDALONE_BUILD.
+if (OPENMP_STANDALONE_BUILD OR "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
+  set(OPENMP_STANDALONE_BUILD TRUE)
+  project(openmp C CXX)
+
+  # CMAKE_BUILD_TYPE was not set, default to Release.
+  if (NOT CMAKE_BUILD_TYPE)
+    set(CMAKE_BUILD_TYPE Release)
+  endif()
+
+  set(OPENMP_LLVM_TOOLS_DIR "" CACHE PATH "Path to LLVM tools for testing.")
+endif()
 
 add_subdirectory(runtime)
 
 
 set(ENABLE_LIBOMPTARGET ON)
 # Currently libomptarget cannot be compiled on Windows or MacOS X.
 # Since the device plugins are only supported on Linux anyway,
 # there is no point in trying to compile libomptarget on other OSes.

openmp/trunk/libomptarget/Build_With_CMake.txt

- To have cmake create a particular type of build generator file simply
   inlude the -G <Generator name> option:
   $ cmake -G "Unix Makefiles" ...
   You can see a list of generators cmake supports by executing cmake with
   no arguments and a list will be printed.
 
 =====================
 Instructions to Build
 =====================
- $ cd libomptarget_top_level/ [ directory with plugins/ , deviceRTLs/ , etc. ]
+ $ cd openmp_top_level/ [ directory with runtime/, libomptarget/, etc. ]
  $ mkdir build
  $ cd build
 
  [ Unix* Libraries ]
  $ cmake -DCMAKE_C_COMPILER=<C Compiler> -DCMAKE_CXX_COMPILER=<C++ Compiler> ..
 
  $ make
  $ make install

openmp/trunk/libomptarget/CMakeLists.txt

 ##===----------------------------------------------------------------------===##
 # 
 #                     The LLVM Compiler Infrastructure
 #
 # This file is dual licensed under the MIT and the University of Illinois Open
 # Source Licenses. See LICENSE.txt for details.
 # 
 ##===----------------------------------------------------------------------===##
 #
 # Build offloading library libomptarget.so.
 #
 ##===----------------------------------------------------------------------===##
 
-# CMAKE libomptarget
-cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
+if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
+  message(FATAL_ERROR "Direct configuration not supported, please use parent directory!")
+endif()
 
 # Add cmake directory to search for custom cmake functions.
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules ${CMAKE_MODULE_PATH})
 
-# Standalone build or part of LLVM?
-set(LIBOMPTARGET_STANDALONE_BUILD FALSE)
-if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}" OR
-   "${CMAKE_SOURCE_DIR}/libomptarget" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
-  project(libomptarget C CXX)
-  set(LIBOMPTARGET_STANDALONE_BUILD TRUE)
-endif()
-  
-  
-if(${LIBOMPTARGET_STANDALONE_BUILD})
+if(OPENMP_STANDALONE_BUILD)
   set(LIBOMPTARGET_ENABLE_WERROR FALSE CACHE BOOL
     "Enable -Werror flags to turn warnings into errors for supporting compilers.")
-  # CMAKE_BUILD_TYPE was not defined, set default to Release
-  if(NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE Release)
-  endif()
   set(LIBOMPTARGET_LIBDIR_SUFFIX "" CACHE STRING
     "suffix of lib installation directory, e.g. 64 => lib64")
 
   # Build all libraries into a common place so that tests can find them.
   set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 else()
   set(LIBOMPTARGET_ENABLE_WERROR ${LLVM_ENABLE_WERROR})
   # If building in tree, we honor the same install suffix LLVM uses.

openmp/trunk/libomptarget/test/CMakeLists.txt

set(LIBOMPTARGET_TEST_CFLAGS "" CACHE STRING
   "Extra compiler flags to send to the test compiler")
 
 if(LIBOMPTARGET_CMAKE_BUILD_TYPE MATCHES debug)
   set(LIBOMPTARGET_DEBUG True)
 else()
   set(LIBOMPTARGET_DEBUG False)
 endif()
 
-if(${LIBOMPTARGET_STANDALONE_BUILD})
+if(${OPENMP_STANDALONE_BUILD})
   # Make sure we can use the console pool for recent cmake and ninja > 1.5
   if(CMAKE_VERSION VERSION_LESS 3.1.20141117)
     set(cmake_3_2_USES_TERMINAL)
   else()
     set(cmake_3_2_USES_TERMINAL USES_TERMINAL)
   endif()
   set(LIBOMPTARGET_TEST_C_COMPILER ${CMAKE_C_COMPILER} CACHE STRING
     "C compiler to use for testing OpenMP offloading library")

openmp/trunk/runtime/Build_With_CMake.txt

- To have cmake create a particular type of build generator file simply
   inlude the -G <Generator name> option:
   $ cmake -G "Unix Makefiles" ...
   You can see a list of generators cmake supports by executing cmake with
   no arguments and a list will be printed.
 
 =====================
 Instructions to Build
 =====================
- $ cd libomp_top_level/ [ directory with src/ , exports/ , tools/ , etc. ]
+ $ cd openmp_top_level/ [ directory with runtime/, etc. ]
  $ mkdir build
  $ cd build
 
  [ Unix* Libraries ]
  $ cmake -DCMAKE_C_COMPILER=<C Compiler> -DCMAKE_CXX_COMPILER=<C++ Compiler> ..
 
  [ Intel(R) Many Integrated Core Library (Intel(R) MIC Library) ]
  $ cmake -DCMAKE_C_COMPILER=<C Compiler> -DCMAKE_CXX_COMPILER=<C++ Compiler> -DLIBOMP_ARCH=mic ..

openmp/trunk/runtime/CMakeLists.txt

 #
 #//===----------------------------------------------------------------------===//
 #//
 #//                     The LLVM Compiler Infrastructure
 #//
 #// This file is dual licensed under the MIT and the University of Illinois Open
 #// Source Licenses. See LICENSE.txt for details.
 #//
 #//===----------------------------------------------------------------------===//
 #
 
-# CMAKE libomp
-cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
+if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
+  message(FATAL_ERROR "Direct configuration not supported, please use parent directory!")
+endif()
 
 # Add cmake directory to search for custom cmake functions
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
 
-# Standalone build or part of LLVM?
-set(LIBOMP_STANDALONE_BUILD FALSE)
-if(OPENMP_STANDALONE_BUILD OR
-   "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}" OR
-   "${CMAKE_SOURCE_DIR}/runtime" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
-  project(libomp C CXX)
-  set(LIBOMP_STANDALONE_BUILD TRUE)
-endif()
-
 # Set libomp version
 set(LIBOMP_VERSION_MAJOR 5)
 set(LIBOMP_VERSION_MINOR 0)
 
 # These include files are in the cmake/ subdirectory
 include(LibompUtils)
 include(LibompGetArchitecture)
 include(LibompHandleFlags)
 include(LibompDefinitions)
 
 # Determine the target architecture
-if(${LIBOMP_STANDALONE_BUILD})
+if(${OPENMP_STANDALONE_BUILD})
   # If adding a new architecture, take a look at cmake/LibompGetArchitecture.cmake
   libomp_get_architecture(LIBOMP_DETECTED_ARCH)
   set(LIBOMP_ARCH ${LIBOMP_DETECTED_ARCH} CACHE STRING
     "The architecture to build for (x86_64/i386/arm/ppc64/ppc64le/aarch64/mic/mips/mips64).")
   # Allow user to choose a suffix for the installation directory.
   set(LIBOMP_LIBDIR_SUFFIX "" CACHE STRING
     "suffix of lib installation directory e.g., 64 => lib64")
   # Should assertions be enabled?  They are on by default.
   set(LIBOMP_ENABLE_ASSERTIONS TRUE CACHE BOOL
     "enable assertions?")
   set(LIBOMP_ENABLE_WERROR FALSE CACHE BOOL
     "Enable -Werror flags to turn warnings into errors for supporting compilers.")
-  # CMAKE_BUILD_TYPE was not defined, set default to Release
-  if(NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE Release)
-  endif()
 else() # Part of LLVM build
   # Determine the native architecture from LLVM.
   string(TOLOWER "${LLVM_TARGET_ARCH}" LIBOMP_NATIVE_ARCH)
   if( LIBOMP_NATIVE_ARCH STREQUAL "host" )
     string(REGEX MATCH "^[^-]*" LIBOMP_NATIVE_ARCH ${LLVM_HOST_TRIPLE})
   endif ()
   if(LIBOMP_NATIVE_ARCH MATCHES "i[2-6]86")
     set(LIBOMP_ARCH i386)

 
 set(LIBOMP_LIB_FILE ${LIBOMP_LIB_NAME}${LIBOMP_LIBRARY_SUFFIX})
 
 # Optional backwards compatibility aliases.
 set(LIBOMP_INSTALL_ALIASES TRUE CACHE BOOL
   "Install libgomp and libiomp5 library aliases for backwards compatibility")
 
 # Print configuration after all variables are set.
-if(${LIBOMP_STANDALONE_BUILD})
+if(${OPENMP_STANDALONE_BUILD})
   libomp_say("Operating System     -- ${CMAKE_SYSTEM_NAME}")
   libomp_say("Target Architecture  -- ${LIBOMP_ARCH}")
   if(${MIC})
     libomp_say("Intel(R) MIC Architecture    -- ${LIBOMP_MIC_ARCH}")
   endif()
   libomp_say("Build Type           -- ${CMAKE_BUILD_TYPE}")
   libomp_say("OpenMP Version       -- ${LIBOMP_OMP_VERSION}")
   libomp_say("Library Kind         -- ${LIBOMP_LIBRARY_KIND}")

openmp/trunk/runtime/src/CMakeLists.txt

 if(${MIC})
   add_dependencies(libomp-micro-tests libomp-test-instr)
 endif()
 add_dependencies(libomp-micro-tests libomp-test-deps)
 
 # Install rules
 # We want to install libomp in DESTDIR/CMAKE_INSTALL_PREFIX/lib
 # We want to install headers in DESTDIR/CMAKE_INSTALL_PREFIX/include
-if(${LIBOMP_STANDALONE_BUILD})
+if(${OPENMP_STANDALONE_BUILD})
   set(LIBOMP_HEADERS_INSTALL_PATH include)
 else()
   string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION ${PACKAGE_VERSION})
   set(LIBOMP_HEADERS_INSTALL_PATH lib${LIBOMP_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
 endif()
 if(WIN32)
   install(TARGETS omp RUNTIME DESTINATION bin)
   install(TARGETS ompimp ARCHIVE DESTINATION lib${LIBOMP_LIBDIR_SUFFIX})

openmp/trunk/runtime/test/CMakeLists.txt

 pythonize_bool(LIBOMP_OMPT_SUPPORT)
 pythonize_bool(LIBOMP_OMPT_OPTIONAL)
 pythonize_bool(LIBOMP_HAVE_LIBM)
 pythonize_bool(LIBOMP_HAVE_LIBATOMIC)
 
 set(LIBOMP_TEST_CFLAGS "" CACHE STRING
   "Extra compiler flags to send to the test compiler")
 
-if(${LIBOMP_STANDALONE_BUILD})
+if(${OPENMP_STANDALONE_BUILD})
   # Make sure we can use the console pool for recent cmake and ninja > 1.5
   if(CMAKE_VERSION VERSION_LESS 3.1.20141117)
     set(cmake_3_2_USES_TERMINAL)
   else()
     set(cmake_3_2_USES_TERMINAL USES_TERMINAL)
   endif()
   set(LIBOMP_TEST_COMPILER ${CMAKE_C_COMPILER} CACHE STRING
     "Compiler to use for testing OpenMP library")

openmp/trunk/www/README.txt

 $ mkdir build && cd build
 $ cmake path/to/llvm -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
 $ make omp
 
 Out-of-tree build:
 
 $ cd where-you-want-to-live
 Check out openmp
-$ cd where-you-want-to-live/openmp/runtime
+$ cd where-you-want-to-live/openmp
 $ mkdir build && cd build
 $ cmake path/to/openmp -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
 $ make
 
 For details about building, please look at Build_With_CMake.txt
 
 Architectures Supported
 =======================

openmp/trunk/www/index.html

<ul>
     <li><code>cmake path/to/llvm -DCMAKE_C_COMPILER=&lt;C compiler&gt; -DCMAKE_CXX_COMPILER=&lt;C++ compiler&gt;</code></li>
     <li><code>make omp</code></li>
   </ul>
 
   <p>Out-of-tree build:</p>
   <ul>
     <li><code>cd where-you-want-to-live</code></li>
     <li>Check out openmp</li>
-    <li><code>cd where-you-want-to-live/openmp/runtime</code></li>
+    <li><code>cd where-you-want-to-live/openmp</code></li>
     <li><code>mkdir build &amp;&amp; cd build</code></li>
     <li><code>cmake path/to/openmp -DCMAKE_C_COMPILER=&lt;C compiler&gt; -DCMAKE_CXX_COMPILER=&lt;C++ compiler&gt;</code></li>
     <li><code>make</code></li>
   </ul>
 
   <p>Full details of how to build are in the
     <a href="README.txt">README.txt</a> and Build_With_CMake.txt (inside the runtime/ subdirectory)
   </p>