[ORC-RT] Initial check-in for a new, top-level ORC runtime project.

Includes CMake files and a placeholder header, library, and tool.

See discussion at
https://discourse.llvm.org/t/rfc-move-orc-executor-support-into-top-level-project/81049

Author: lhames

llvm/CMakeLists.txt

@@ -155,7 +155,7 @@ endif()
 # As we migrate runtimes to using the bootstrapping build, the set of default runtimes
 # should grow as we remove those runtimes from LLVM_ENABLE_PROJECTS above.
 set(LLVM_DEFAULT_RUNTIMES "libcxx;libcxxabi;libunwind")
-set(LLVM_SUPPORTED_RUNTIMES "libc;libunwind;libcxxabi;pstl;libcxx;compiler-rt;openmp;llvm-libgcc;offload")
+set(LLVM_SUPPORTED_RUNTIMES "libc;libunwind;libcxxabi;pstl;libcxx;compiler-rt;openmp;llvm-libgcc;offload;orc-rt")
 set(LLVM_ENABLE_RUNTIMES "" CACHE STRING
   "Semicolon-separated list of runtimes to build, or \"all\" (${LLVM_DEFAULT_RUNTIMES}). Supported runtimes are ${LLVM_SUPPORTED_RUNTIMES}.")
 if(LLVM_ENABLE_RUNTIMES STREQUAL "all")

llvm/projects/CMakeLists.txt

@@ -9,6 +9,7 @@ foreach(entry ${entries})
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/libcxx) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/libcxxabi) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/libunwind) AND
+       (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/orc-rt) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/test-suite) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/openmp) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/cross-project-tests))
@@ -33,6 +34,7 @@ if(${LLVM_BUILD_RUNTIME})
     add_llvm_external_project(libc)
     add_llvm_external_project(libcxxabi)
     add_llvm_external_project(libcxx)
+    add_llvm_external_project(orc-rt)
   endif()
   if(NOT LLVM_BUILD_EXTERNAL_COMPILER_RT)
     add_llvm_external_project(compiler-rt)

orc-rt/CMakeLists.txt

@@ -0,0 +1,47 @@
+# CMake build for ORC-RT.
+
+#===============================================================================
+# Setup Project
+#===============================================================================
+
+cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "orc-rt")
+
+set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
+
+include(${LLVM_COMMON_CMAKE_UTILS}/Modules/CMakePolicy.cmake
+  NO_POLICY_SCOPE)
+
+# Add path for custom orc-rt modules.
+list(INSERT CMAKE_MODULE_PATH 0
+#  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
+#  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
+  "${LLVM_COMMON_CMAKE_UTILS}"
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+  )
+
+set(CMAKE_FOLDER "orc-rt")
+
+set(LIBORCRT_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(LIBORCRT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
+#===============================================================================
+# Setup CMake Options
+#===============================================================================
+
+set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to conform to")
+set(CMAKE_CXX_STANDARD_REQUIRED YES)
+set(CMAKE_CXX_EXTENSIONS NO)
+
+#================================
+# Setup Compiler Flags
+#================================
+
+# Configure compiler. Must happen after setting the target flags.
+
+#===============================================================================
+# Setup Source Code
+#===============================================================================
+
+add_subdirectory(lib)
+add_subdirectory(tools)

orc-rt/include/orc-rt-c/orc-rt.h

@@ -0,0 +1,27 @@
+/*===- orc-rt-c/orc-rt.h - Placeholder header for orc-rt ----------*- C -*-===*\
+|*                                                                            *|
+|* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
+|* Exceptions.                                                                *|
+|* See https://llvm.org/LICENSE.txt for license information.                  *|
+|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* Placeholder header for initial orc-rt checkin                              *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef ORC_RT_C_ORC_RT_H
+#define ORC_RT_C_ORC_RT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void orc_rt(void);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* ORC_RT_C_ORC_RT_H */

orc-rt/lib/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(prelink)

orc-rt/lib/prelink/CMakeLists.txt

@@ -0,0 +1 @@
+add_library(orc-rt-prelink STATIC orc-rt-prelink.cpp)

orc-rt/lib/prelink/orc-rt-prelink.cpp

@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+extern "C" void orc_rt(void) {
+  printf("hello, world!\n");
+}

orc-rt/tools/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(orc-executor)

orc-rt/tools/orc-executor/CMakeLists.txt

@@ -0,0 +1,3 @@
+add_executable(orc-executor orc-executor.cpp)
+target_link_libraries(orc-executor PRIVATE orc-rt-prelink)
+target_include_directories(orc-executor PRIVATE ../../include)

orc-rt/tools/orc-executor/orc-executor.cpp

@@ -0,0 +1,6 @@
+#include "orc-rt-c/orc-rt.h"
+
+int main(int argc, char *argv[]) {
+  orc_rt();
+  return 0;
+}