Turn CUDA support off by default

1. Stop depending on the deprecated FindCUDA module,
2. Add a new FindOmrCuda module, which locates a minimum set of headers
   needed by OMR,
3. Stop automatically enabling OMR_OPT_CUDA when the dependencies are
   present.

Signed-off-by: Robert Young <rwy0717@gmail.com>

CMakeLists.txt

@@ -1,5 +1,5 @@
 ###############################################################################
-# Copyright (c) 2017, 2018 IBM Corp. and others
+# Copyright (c) 2017, 2020 IBM Corp. and others
 #
 # This program and the accompanying materials are made available under
 # the terms of the Eclipse Public License 2.0 which accompanies this
@@ -63,23 +63,6 @@ set(OMR_INSTALL_ARCHIVE_DIR ${CMAKE_INSTALL_LIBDIR} CACHE PATH "Installation dir
 set(OMR_INSTALL_INC_DIR ${CMAKE_INSTALL_INCLUDEDIR} CACHE PATH "Installation directory for headers")
 set(OMR_INSTALL_DATA_DIR ${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME} CACHE PATH "Installation directory for data files")
 
-###
-### CUDA Support
-###
-
-if (OMR_ENV_DATA64)
-	find_package(Threads)
-	if(Threads_FOUND)
-		# Threads mush be found before we can look for CUDA.
-		# FindCuda will error out if Threads is missing, even though CUDA itself is optional.
-		find_package(CUDA)
-	else()
-		set(CUDA_FOUND OFF CACHE BOOL "CUDA is disabled (threads not found)")
-	endif()
-else()
-	set(CUDA_FOUND OFF CACHE BOOL "CUDA is disabled")
-endif()
-
 ###
 ### Versions and stuff
 ###

buildenv/jenkins/jobs/builds/Build-linux_x86-64

@@ -34,7 +34,7 @@ pipeline {
 
                     dir('build') {
                         echo 'Configure...'
-                        sh '''cmake -Wdev -C../cmake/caches/Travis.cmake ..'''
+                        sh '''cmake -Wdev -C../cmake/caches/Travis.cmake -DOMR_OPT_CUDA=ON -DOMR_CUDA_HOME=/usr/local/cuda ..'''
 
                         echo 'Compile...'
                         sh '''make -j4'''

buildenv/jenkins/jobs/pull-requests/PullRequest-linux_x86-64

@@ -20,7 +20,7 @@ pipeline {
 
                     dir('build') {
                         echo 'Configure...'
-                        sh '''cmake -Wdev -C../cmake/caches/Travis.cmake ..''' 
+                        sh '''cmake -Wdev -C../cmake/caches/Travis.cmake -DOMR_OPT_CUDA=ON -DOMR_CUDA_HOME=/usr/local/cuda ..'''
 
                         echo 'Compile...'
                         sh '''make -j4'''

cmake/config.cmake

@@ -201,6 +201,6 @@ set(OMR_NOTIFY_POLICY_CONTROL OFF CACHE BOOL "TODO: Document")
 
 set(OMR_ENV_GCC OFF CACHE BOOL "TODO: Document")
 
-set(OMR_OPT_CUDA ${CUDA_FOUND} CACHE BOOL "Enable CUDA support in OMR")
+set(OMR_OPT_CUDA OFF CACHE BOOL "Enable CUDA support in OMR")
 
 set(OMR_SANITIZE OFF CACHE STRING "Sanitizer selection. Only has an effect on GNU or Clang")

cmake/modules/FindOmrCuda.cmake

@@ -0,0 +1,66 @@
+###############################################################################
+# Copyright (c) 2019, 2020 IBM Corp. and others
+#
+# This program and the accompanying materials are made available under
+# the terms of the Eclipse Public License 2.0 which accompanies this
+# distribution and is available at http://eclipse.org/legal/epl-2.0
+# or the Apache License, Version 2.0 which accompanies this distribution
+# and is available at https://www.apache.org/licenses/LICENSE-2.0.
+#
+# This Source Code may also be made available under the following Secondary
+# Licenses when the conditions for such availability set forth in the
+# Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
+# version 2 with the GNU Classpath Exception [1] and GNU General Public
+# License, version 2 with the OpenJDK Assembly Exception [2].
+#
+# [1] https://www.gnu.org/software/classpath/license.html
+# [2] http://openjdk.java.net/legal/assembly-exception.html
+#
+# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+#############################################################################
+
+# This module locates a minimal set of cuda headers, required by the OMR_OPT_CUDA flag.
+# This module will search for CUDA resources in only one directory. The variables tested, in order of preference, are:
+#
+# 1. The cmake variable OMR_CUDA_HOME, if set.
+# 2. The cmake variable CUDA_HOME, if set.
+# 3. The environment variable CUDA_HOME, if set.
+#
+
+include(FindPackageHandleStandardArgs)
+
+set(OMR_CUDA_HOME "NOTFOUND" CACHE STRING "Path to the CUDA SDK. Takes precedence over CUDA_HOME in OMR.")
+set(OmrCuda_INCLUDE_DIRS "OmrCuda_INCLUDE_DIRS-NOTFOUND")
+
+# Establish which directory we are searching in
+
+set(OmrCuda_SEARCH_DIR "")
+
+if(OMR_CUDA_HOME)
+	set(OmrCuda_SEARCH_DIR "${OMR_CUDA_HOME}")
+elseif(CUDA_HOME)
+	set(OmrCuda_SEARCH_DIR "${CUDA_HOME}")
+elseif($ENV{CUDA_HOME})
+	set("$ENV{CUDA_HOME}")
+else()
+	message(WARNING "CUDA support requested, but OMR_CUDA_HOME/CUDA_HOME are not set.")
+endif()
+
+# Try to locate the main CUDA include directory by finding cuda.h
+
+find_path(OmrCuda_INCLUDE_DIR
+	NAMES cuda.h
+	PATHS ${OmrCuda_SEARCH_DIR}
+	PATH_SUFFIXES include Headers
+	DOC "The CUDA include directory"
+	NO_DEFAULT_PATH
+)
+
+find_package_handle_standard_args(OmrCuda
+	DEFAULT_MSG
+	OmrCuda_INCLUDE_DIR
+)
+
+if(OmrCuda_FOUND)
+	set(OmrCuda_INCLUDE_DIRS "${OmrCuda_INCLUDE_DIR}")
+endif()

port/CMakeLists.txt

@@ -22,7 +22,11 @@
 
 include(OmrFindFiles)
 
-if (OMR_HOST_OS STREQUAL "zos")
+if(OMR_OPT_CUDA)
+	find_package(OmrCuda REQUIRED)
+endif()
+
+if(OMR_HOST_OS STREQUAL "zos")
 	include(OmrMetalC)
 endif()
 
@@ -44,10 +48,10 @@ target_include_directories(omrport_obj
 		$<TARGET_PROPERTY:omr_base,INTERFACE_INCLUDE_DIRECTORIES>
 )
 
-if (OMR_OPT_CUDA)
+if(OMR_OPT_CUDA)
 	target_include_directories(omrport_obj
 		PRIVATE
-			${CUDA_INCLUDE_DIRS}
+			${OmrCuda_INCLUDE_DIRS}
 	)
 endif()