[Openmp-commits] [openmp] 26790ed - [libomptarget] Require LLVM source tree to build libomptarget

[Jon Chesterfield via Openmp-commits]

Author: Jon Chesterfield
Date: 2020-10-21T18:53:00+01:00
New Revision: 26790ed248870a1e293e844945bf677825a43084

URL: https://github.com/llvm/llvm-project/commit/26790ed248870a1e293e844945bf677825a43084
DIFF: https://github.com/llvm/llvm-project/commit/26790ed248870a1e293e844945bf677825a43084.diff

LOG: [libomptarget] Require LLVM source tree to build libomptarget

[libomptarget] Require LLVM source tree to build libomptarget

This is to permit reliably #including files from the LLVM tree in libomptarget,
as an improvement on the copy and paste that is currently in use. See D87841
for the first example of removing duplication given this new requirement.

The weekly openmp dev call reached consensus on this approach. See also D87841
for some alternatives that were considered. In the future, we may want to
introduce a new top level repo for shared constants, or start using the ADT
library within openmp.

This will break sufficiently exotic build systems, trivial fixes as below.

Building libomptarget as part of the monorepo will continue to work.
If openmp is built separately, it now requires a cmake macro indicating
where to find the LLVM source tree.

If openmp is built separately, without the llvm source tree already on disk,
the build machine will need a copy of a subset of the llvm source tree and
the cmake macro indicating where it is.

Reviewed By: protze.joachim

Differential Revision: https://reviews.llvm.org/D89426

Added: 
    

Modified: 
    openmp/CMakeLists.txt
    openmp/libomptarget/CMakeLists.txt
    openmp/libomptarget/plugins/amdgpu/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/openmp/CMakeLists.txt b/openmp/CMakeLists.txt
index 51f496eff1bf..6cc36d9b7577 100644
--- a/openmp/CMakeLists.txt
+++ b/openmp/CMakeLists.txt
@@ -66,6 +66,20 @@ if (APPLE OR WIN32 OR NOT OPENMP_HAVE_STD_CPP14_FLAG)
   set(ENABLE_LIBOMPTARGET OFF)
 endif()
 
+# Attempt to locate LLVM source, required by libomptarget
+if (NOT LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR)
+  if (LLVM_MAIN_INCLUDE_DIR)
+    set(LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR ${LLVM_MAIN_INCLUDE_DIR})
+  elseif (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/../llvm/include)
+    set(LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../llvm/include)
+  endif()
+endif()
+
+if (NOT LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR)
+  message(STATUS "Missing definition for LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR, disabling libomptarget")
+  set(ENABLE_LIBOMPTARGET OFF)
+endif()
+
 option(OPENMP_ENABLE_LIBOMPTARGET "Enable building libomptarget for offloading."
        ${ENABLE_LIBOMPTARGET})
 if (OPENMP_ENABLE_LIBOMPTARGET)

diff  --git a/openmp/libomptarget/CMakeLists.txt b/openmp/libomptarget/CMakeLists.txt
index c1bc29faaf45..7ef0bafdf3c6 100644
--- a/openmp/libomptarget/CMakeLists.txt
+++ b/openmp/libomptarget/CMakeLists.txt
@@ -29,6 +29,11 @@ include(LibomptargetUtils)
 # Get dependencies for the 
diff erent components of the project.
 include(LibomptargetGetDependencies)
 
+# LLVM source tree is required at build time for libomptarget
+if (NOT LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR)
+  message(FATAL_ERROR "Missing definition for LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR")
+endif()
+
 # This is a list of all the targets that are supported/tested right now.
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} aarch64-unknown-linux-gnu")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64le-ibm-linux-gnu")

diff  --git a/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt b/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt
index 3882b777f5b1..0c50ffdf2fa6 100644
--- a/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt
+++ b/openmp/libomptarget/plugins/amdgpu/CMakeLists.txt
@@ -30,8 +30,8 @@ if(NOT CMAKE_SYSTEM_PROCESSOR MATCHES "(x86_64)|(ppc64le)|(aarch64)$" AND CMAKE_
   return()
 endif()
 
-if (NOT LLVM_MAIN_INCLUDE_DIR)
-  libomptarget_say("Not building AMDGPU plugin: Missing definition for LLVM_MAIN_INCLUDE_DIR")
+if (NOT LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR)
+  libomptarget_say("Not building AMDGPU plugin: Missing definition for LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR")
   return()
 endif()
 
@@ -50,7 +50,7 @@ endif()
 
 include_directories(
   ${CMAKE_CURRENT_SOURCE_DIR}/impl
-  ${LLVM_MAIN_INCLUDE_DIR}
+  ${LIBOMPTARGET_LLVM_MAIN_INCLUDE_DIR}
 )
 
 add_library(omptarget.rtl.amdgpu SHARED