# Copyright Advanced Micro Devices, Inc.
# SPDX-License-Identifier: MIT

# Get access to LLVM_VERSION_MAJOR
include("${THEROCK_SOURCE_DIR}/compiler/amd-llvm/cmake/Modules/LLVMVersion.cmake")

# Build LLVM and the comgr dependency.
# Note that in LLVM "BUILD_SHARED_LIBS" enables an unsupported development mode.
# The flag you want for a shared library build is LLVM_BUILD_LLVM_DYLIB.
set(BUILD_SHARED_LIBS OFF)
if(WIN32)
  set(LLVM_BUILD_LLVM_DYLIB OFF)
  set(LLVM_LINK_LLVM_DYLIB OFF)
  set(LIBUNWIND_ENABLE_SHARED OFF)
  set(LIBUNWIND_ENABLE_STATIC ON)
  # TODO(#36): Enable libunwind, libcxx, and libcxxabi on Windows?
  #     Should they be supported? What depends on them?
  set(LLVM_ENABLE_LIBCXX OFF)
  set(LLVM_ENABLE_RUNTIMES "compiler-rt" CACHE STRING "Enabled runtimes" FORCE)
  set(LLVM_ENABLE_PROJECTS "clang;lld;clang-tools-extra" CACHE STRING "Enable LLVM projects" FORCE)
else()
  set(LLVM_BUILD_LLVM_DYLIB ON)
  set(LLVM_LINK_LLVM_DYLIB ON)
  set(LLVM_ENABLE_LIBCXX ON)
  set(LLVM_ENABLE_PROJECTS "clang;lld;clang-tools-extra;flang" CACHE STRING "Enable LLVM projects" FORCE)
  set(LLVM_ENABLE_RUNTIMES "compiler-rt;libunwind;libcxx;libcxxabi;openmp;offload" CACHE STRING "Enabled runtimes" FORCE)
  if("offload" IN_LIST LLVM_ENABLE_RUNTIMES)
    set(OPENMP_ENABLE_LIBOMPTARGET ON)
    set(LIBOMPTARGET_BUILD_DEVICE_FORTRT ON)
    set(LIBOMPTARGET_ENABLE_DEBUG ON)
    set(LIBOMPTARGET_NO_SANITIZER_AMDGPU ON)
    set(LIBOMP_INSTALL_RPATH "\$ORIGIN:\$ORIGIN/../lib:\$ORIGIN/../../lib:\$ORIGIN/../../../lib")
    set(LIBOMPTARGET_EXTERNAL_PROJECT_HSA_PATH "${THEROCK_ROCM_SYSTEMS_SOURCE_DIR}/projects/rocr-runtime")
    set(OFFLOAD_EXTERNAL_PROJECT_UNIFIED_ROCR ON)
    # There is an issue with finding the zstd config built by TheRock when zstd
    # is searched for in the llvm config. LLVM has a FindZSTD.cmake that is
    # found in module mode, which ultimately fails to locate the library.
    # For now we will switch the priorty for find_package to first search in
    # CONFIG mode.
    set(RUNTIMES_CMAKE_ARGS "-DCMAKE_FIND_PACKAGE_PREFER_CONFIG=ON")

    # Use DWARF4 for sanitizer builds. dwz (the DWARF optimization tool used in
    # Debian/Ubuntu packaging) doesn't fully support DWARF5 - it fails with
    # "Unknown debugging section .debug_str_offsets" even in version 0.16
    # (Ubuntu 26.04). This is an upstream dwz limitation, not something we
    # can fix by updating distro packages. Revisit if dwz gains DWARF5 support.
    if(THEROCK_SANITIZER STREQUAL "ASAN" OR THEROCK_SANITIZER STREQUAL "HOST_ASAN" OR THEROCK_SANITIZER STREQUAL "TSAN")
        string(APPEND RUNTIMES_CMAKE_ARGS ";-DCMAKE_C_FLAGS=${CMAKE_C_FLAGS} -gdwarf-4;-DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS} -gdwarf-4")
    endif()

    # TODO: Guard for amd-staging only. Remove condition when compiler branch is updated.
    if(EXISTS "${THEROCK_SOURCE_DIR}/compiler/amd-llvm/openmp/device/CMakeLists.txt")
      list(APPEND LLVM_ENABLE_RUNTIMES "flang-rt")
      set(LLVM_RUNTIME_TARGETS "default;amdgcn-amd-amdhsa")
      set(RUNTIMES_amdgcn-amd-amdhsa_LLVM_ENABLE_PER_TARGET_RUNTIME_DIR ON)
      set(RUNTIMES_amdgcn-amd-amdhsa_LLVM_ENABLE_RUNTIMES "compiler-rt;libc;libcxx;libcxxabi;flang-rt;openmp")
      set(RUNTIMES_amdgcn-amd-amdhsa_FLANG_RT_LIBC_PROVIDER "llvm")
      set(RUNTIMES_amdgcn-amd-amdhsa_FLANG_RT_LIBCXX_PROVIDER "llvm")
      set(RUNTIMES_amdgcn-amd-amdhsa_CACHE_FILES "${CMAKE_CURRENT_SOURCE_DIR}/../compiler-rt/cmake/caches/GPU.cmake;${CMAKE_CURRENT_SOURCE_DIR}/../libcxx/cmake/caches/AMDGPU.cmake")
      set(FLANG_RUNTIME_F128_MATH_LIB "libquadmath")
      set(LIBOMPTARGET_BUILD_DEVICE_FORTRT ON)
      #TODO: Enable when HWLOC dependency is figured out
      #set(LIBOMP_USE_HWLOC ON)
    endif()
  endif()
  # Setting "LIBOMP_COPY_EXPORTS" to `OFF` "aids parallel builds to not interfere
  # with each other" as libomp and generated headers are copied into the original
  # source otherwise. Defaults to `ON`.
  set(LIBOMP_COPY_EXPORTS OFF)
endif()

# Set the LLVM_ENABLE_PROJECTS variable before including LLVM's CMakeLists.txt
# Only enable BUILD_TESTING if LLVM tests are explicitly enabled
if(THEROCK_BUILD_LLVM_TESTS)
  set(BUILD_TESTING ON CACHE BOOL "Enable building LLVM tests" FORCE)
else()
  set(BUILD_TESTING OFF CACHE BOOL "DISABLE BUILDING TESTS IN SUBPROJECTS" FORCE)
endif()

# Enable LLVM tools when tests are enabled (tests need the tools) or when explicitly requested
if(THEROCK_BUILD_LLVM_TESTS OR THEROCK_BUILD_LLVM_TOOLS OR THEROCK_BUILD_COMGR_TESTS)
  set(LLVM_BUILD_TOOLS ON CACHE BOOL "Build LLVM tools required for tests" FORCE)
  set(LLVM_INSTALL_UTILS ON CACHE BOOL "Install LLVM utility binaries like FileCheck" FORCE)
endif()
# we have never enabled benchmarks,
# disabling more explicitly after a bug fix enabled.
set(LLVM_INCLUDE_BENCHMARKS OFF)
set(LLVM_TARGETS_TO_BUILD "AMDGPU;Native;SPIRV" CACHE STRING "Enable LLVM Targets" FORCE)

# Packaging.
set(PACKAGE_VENDOR "AMD" CACHE STRING "Vendor" FORCE)

# Build device-libs and spirv-llvm-translator as part of the core
# compiler default (as opposed to other components that are *users*
# of the compiler).
set(LLVM_EXTERNAL_ROCM_DEVICE_LIBS_SOURCE_DIR "${THEROCK_SOURCE_DIR}/compiler/amd-llvm/amd/device-libs")
set(LLVM_EXTERNAL_SPIRV_LLVM_TRANSLATOR_SOURCE_DIR "${THEROCK_SOURCE_DIR}/compiler/spirv-llvm-translator")
set(LLVM_EXTERNAL_PROJECTS "rocm-device-libs;spirv-llvm-translator" CACHE STRING "Enable extra projects" FORCE)

# TODO2: This mechanism has races in certain situations, failing to create a
# symlink. Revisit once devicemanager code is made more robust.
# TODO: Arrange for the devicelibs to be installed to the clange resource dir
# by default. This corresponds to the layout for ROCM>=7. However, not all
# code (specifically the AMDDeviceLibs.cmake file) has adapted to the new
# location, so we have to also make them available at amdgcn. There are cache
# options to manage this transition but they require knowing the clange resource
# dir. In order to avoid drift, we just fixate that too. This can all be
# removed in a future version.
# set(CLANG_RESOURCE_DIR "../lib/clang/${LLVM_VERSION_MAJOR}" CACHE STRING "Resource dir" FORCE)
# set(ROCM_DEVICE_LIBS_BITCODE_INSTALL_LOC_NEW "lib/clang/${LLVM_VERSION_MAJOR}/amdgcn" CACHE STRING "New devicelibs loc" FORCE)
# set(ROCM_DEVICE_LIBS_BITCODE_INSTALL_LOC_OLD "amdgcn" CACHE STRING "Old devicelibs loc" FORCE)

# Setup the install rpath (let CMake handle build RPATH per usual):
# * Executables and libraries can always search their adjacent lib directory
#   (which may be the same as the origin for libraries).
# * Files in lib/llvm/(bin|lib) should search the project-wide lib/ directory
#   so that dlopen of runtime files from the compiler can work.
# * One might think that only EXEs need to be build this way, but the dlopen
#   utilities can be compiled into libLLVM, in which case, that RUNPATH is
#   primary.
if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
  set(CMAKE_INSTALL_RPATH "$ORIGIN/../lib;$ORIGIN/../../../lib;$ORIGIN/../../rocm_sysdeps/lib")
endif()

# Disable all implicit LLVM tools by default so that we can allow-list just what
# we want. It is unfortunate that LLVM doesn't have a global option to do this
# bulk disabling. In the absence of that, we manually generate options using
# the same logic as `create_llvm_tool_options` in `AddLLVM.cmake`. If this
# ever drifts, we will build extra tools and (presumably) someone will notice
# the bloat.

function(therock_set_implicit_llvm_options type tools_dir required_tool_names)
  file(GLOB subdirs "${tools_dir}/*")
  foreach(dir ${subdirs})
    if(NOT IS_DIRECTORY "${dir}" OR NOT EXISTS "${dir}/CMakeLists.txt")
      continue()
    endif()
    cmake_path(GET dir FILENAME toolname)
    string(REPLACE "-" "_" toolname "${toolname}")
    string(TOUPPER "${toolname}" toolname)
    set(_option_name "${type}_TOOL_${toolname}_BUILD")
    set(_option_value OFF)
    if("${toolname}" IN_LIST required_tool_names)
      set(_option_value ON)
    endif()
    message(STATUS "Implicit tool option: ${_option_name} = ${_option_value}")
    set(${_option_name} "${_option_value}" CACHE BOOL "Implicit disable ${type} tool" FORCE)
  endforeach()
endfunction()

# When LLVM LIT tests or all tools are requested, build everything (don't selectively disable).
# Comgr tests only need tools already in the minimal required set (clang, llvm-dis, llvm-objdump,
# FileCheck via LLVM_INSTALL_UTILS), so they don't need the full tool build.
if(NOT THEROCK_BUILD_LLVM_TESTS AND NOT THEROCK_BUILD_LLVM_TOOLS)
  block()
    # This list contains the minimum tooling that must be enabled to build LLVM.
    # It is empically derived (either configure or ninja invocation will fail
    # on a missing tool).
    set(_llvm_required_tools
      LLVM_AR
      LLVM_AS
      LLVM_CONFIG
      LLVM_COV
      LLVM_CXXFILT
      LLVM_DIS
      LLVM_DWARFDUMP
      LLVM_LINK
      LLVM_MC
      LLVM_NM
      LLVM_OFFLOAD_BINARY
      LLVM_PROFDATA
      LLVM_SHLIB
      LLVM_OBJCOPY
      LLVM_OBJDUMP
      LLVM_READOBJ
      LLVM_SYMBOLIZER
      OPT
      YAML2OBJ
    )
    if(WIN32)
      # These can be provided by the "C++ Clang tools for Windows" in MSVC, but
      # we might as well build them from source ourselves.
      list(APPEND _llvm_required_tools "LLVM_DLLTOOL")
      list(APPEND _llvm_required_tools "LLVM_LIB")
      list(APPEND _llvm_required_tools "LLVM_RANLIB")
    endif()
    therock_set_implicit_llvm_options(LLVM "${CMAKE_CURRENT_SOURCE_DIR}/tools" "${_llvm_required_tools}")

    # Clang tools that are required.
    set(_clang_required_tools
      CLANG_HIP
      CLANG_OFFLOAD_BUNDLER
      CLANG_OFFLOAD_PACKAGER
      CLANG_OFFLOAD_WRAPPER
      CLANG_LINKER_WRAPPER
      CLANG_SHLIB
      DRIVER
      LIBCLANG
      OFFLOAD_ARCH
    )
    if(WIN32)
      # These can be provided by the "C++ Clang tools for Windows" in MSVC, but
      # we might as well build them from source ourselves.
      list(APPEND _clang_required_tools "CLANG_SCAN_DEPS")
    endif()
    therock_set_implicit_llvm_options(CLANG "${CMAKE_CURRENT_SOURCE_DIR}/../clang/tools" "${_clang_required_tools}")
  endblock()
endif()