[libcxxabi,libunwind] support running tests in standalone mode

Remove check for standalone and shared library mode in libcxxabi to
allow including tests in said mode. This check prevented running the
tests in standalone mode with static libraries, which is the case for
baremetal targets.

Fix check-unwind target trying to use a non-existent llvm-lit executable
in standalone mode. Copy the HandleOutOfTreeLLVM logic from libcxxabi to
libunwind in order to make the tests work in standalone mode.

Reviewed By: ldionne, #libc_abi, #libc

Differential Revision: https://reviews.llvm.org/D86540

GitOrigin-RevId: 8c03fdf34a659925a3f09c8f54016e47ea1c7519
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c4d76ea..5f0c726 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,6 +21,11 @@
   ${CMAKE_MODULE_PATH}
   )
 
+set(LIBCXXABI_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
+set(LIBCXXABI_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
+set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
+        "Specify path to libc++ source.")
+
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
   project(libcxxabi CXX C)
 
@@ -29,6 +34,16 @@
   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
   set(PACKAGE_BUGREPORT "llvm-bugs@lists.llvm.org")
 
+  # Add the CMake module path of libcxx so we can reuse HandleOutOfTreeLLVM.cmake
+  set(LIBCXXABI_LIBCXX_CMAKE_PATH "${LIBCXXABI_LIBCXX_PATH}/cmake/Modules")
+  list(APPEND CMAKE_MODULE_PATH "${LIBCXXABI_LIBCXX_CMAKE_PATH}")
+
+  # In a standalone build, we don't have llvm to automatically generate the
+  # llvm-lit script for us.  So we need to provide an explicit directory that
+  # the configurator should write the script into.
+  set(LIBCXXABI_STANDALONE_BUILD 1)
+  set(LLVM_LIT_OUTPUT_DIR "${LIBCXXABI_BINARY_DIR}/bin")
+
   # Find the LLVM sources and simulate LLVM CMake options.
   include(HandleOutOfTreeLLVM)
 endif()
@@ -126,8 +141,6 @@
   message(FATAL_ERROR "libc++abi must be built as either a shared or static library.")
 endif()
 
-set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
-    "Specify path to libc++ source.")
 set(LIBCXXABI_LIBCXX_INCLUDES "${LIBCXXABI_LIBCXX_PATH}/include" CACHE PATH
     "Specify path to libc++ includes.")
 message(STATUS "Libc++abi will be using libc++ includes from ${LIBCXXABI_LIBCXX_INCLUDES}")
@@ -151,9 +164,6 @@
   ${CMAKE_MODULE_PATH}
   )
 
-set(LIBCXXABI_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
-set(LIBCXXABI_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
-
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
   set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
@@ -475,20 +485,6 @@
 add_subdirectory(src)
 
 if (LIBCXXABI_INCLUDE_TESTS)
-  if (LIBCXXABI_STANDALONE_BUILD AND NOT LIBCXXABI_ENABLE_SHARED)
-    # We can't reasonably test the system C++ library with a static
-    # libc++abi.  We either need to be able to replace libc++abi at
-    # run time (with a shared libc++abi), or we need to be able to
-    # replace the C++ runtime (with a non- standalone build).
-    message(WARNING "The libc++abi tests aren't valid when libc++abi "
-                    "is built standalone (i.e. outside of "
-                    "llvm/projects/libcxxabi ) and is built without "
-                    "a shared library.  Either build a shared "
-                    "library, build libc++abi at the same time as "
-                    "you build libc++, or do without testing.  No "
-                    "check target will be available!")
-  else()
-    add_subdirectory(test)
-    add_subdirectory(fuzz)
-  endif()
+  add_subdirectory(test)
+  add_subdirectory(fuzz)
 endif()
diff --git a/cmake/Modules/HandleOutOfTreeLLVM.cmake b/cmake/Modules/HandleOutOfTreeLLVM.cmake
deleted file mode 100644
index c43308e..0000000
--- a/cmake/Modules/HandleOutOfTreeLLVM.cmake
+++ /dev/null
@@ -1,142 +0,0 @@
-macro(find_llvm_parts)
-# Rely on llvm-config.
-  set(CONFIG_OUTPUT)
-  if(NOT LLVM_CONFIG_PATH)
-    find_program(LLVM_CONFIG_PATH "llvm-config")
-  endif()
-  if(DEFINED LLVM_PATH)
-    set(LLVM_INCLUDE_DIR ${LLVM_INCLUDE_DIR} CACHE PATH "Path to llvm/include")
-    set(LLVM_PATH ${LLVM_PATH} CACHE PATH "Path to LLVM source tree")
-    set(LLVM_MAIN_SRC_DIR ${LLVM_PATH})
-    set(LLVM_CMAKE_PATH "${LLVM_PATH}/cmake/modules")
-    if (NOT IS_DIRECTORY "${LLVM_PATH}")
-      message(FATAL_ERROR "The provided LLVM_PATH (${LLVM_PATH}) is not a valid directory")
-    endif()
-  elseif(LLVM_CONFIG_PATH)
-    message(STATUS "Found LLVM_CONFIG_PATH as ${LLVM_CONFIG_PATH}")
-    set(LIBCXXABI_USING_INSTALLED_LLVM 1)
-    set(CONFIG_COMMAND ${LLVM_CONFIG_PATH}
-      "--includedir"
-      "--prefix"
-      "--src-root")
-    execute_process(
-      COMMAND ${CONFIG_COMMAND}
-      RESULT_VARIABLE HAD_ERROR
-      OUTPUT_VARIABLE CONFIG_OUTPUT
-    )
-    if(NOT HAD_ERROR)
-      string(REGEX REPLACE
-        "[ \t]*[\r\n]+[ \t]*" ";"
-        CONFIG_OUTPUT ${CONFIG_OUTPUT})
-    else()
-      string(REPLACE ";" " " CONFIG_COMMAND_STR "${CONFIG_COMMAND}")
-      message(STATUS "${CONFIG_COMMAND_STR}")
-      message(FATAL_ERROR "llvm-config failed with status ${HAD_ERROR}")
-    endif()
-
-    list(GET CONFIG_OUTPUT 0 INCLUDE_DIR)
-    list(GET CONFIG_OUTPUT 1 LLVM_OBJ_ROOT)
-    list(GET CONFIG_OUTPUT 2 MAIN_SRC_DIR)
-
-    set(LLVM_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
-    set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
-    set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
-
-    # --cmakedir is supported since llvm r291218 (4.0 release)
-    execute_process(
-      COMMAND ${LLVM_CONFIG_PATH} --cmakedir
-      RESULT_VARIABLE HAD_ERROR
-      OUTPUT_VARIABLE CONFIG_OUTPUT
-      ERROR_QUIET)
-    if(NOT HAD_ERROR)
-      string(STRIP "${CONFIG_OUTPUT}" LLVM_CMAKE_PATH_FROM_LLVM_CONFIG)
-      file(TO_CMAKE_PATH "${LLVM_CMAKE_PATH_FROM_LLVM_CONFIG}" LLVM_CMAKE_PATH)
-    else()
-      file(TO_CMAKE_PATH "${LLVM_BINARY_DIR}" LLVM_BINARY_DIR_CMAKE_STYLE)
-      set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR_CMAKE_STYLE}/lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm")
-    endif()
-  else()
-    set(LLVM_FOUND OFF)
-    message(WARNING "UNSUPPORTED LIBCXXABI CONFIGURATION DETECTED: "
-                    "llvm-config not found and LLVM_PATH not defined.\n"
-                    "Reconfigure with -DLLVM_CONFIG_PATH=path/to/llvm-config "
-                    "or -DLLVM_PATH=path/to/llvm-source-root.")
-    return()
-  endif()
-
-  if (EXISTS "${LLVM_CMAKE_PATH}")
-    list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_PATH}")
-  elseif (EXISTS "${LLVM_MAIN_SRC_DIR}/cmake/modules")
-    list(APPEND CMAKE_MODULE_PATH "${LLVM_MAIN_SRC_DIR}/cmake/modules")
-  else()
-    set(LLVM_FOUND OFF)
-    message(WARNING "Neither ${LLVM_CMAKE_PATH} nor ${LLVM_MAIN_SRC_DIR}/cmake/modules found")
-    return()
-  endif()
-
-  set(LLVM_FOUND ON)
-endmacro(find_llvm_parts)
-
-macro(configure_out_of_tree_llvm)
-  message(STATUS "Configuring for standalone build.")
-  set(LIBCXXABI_STANDALONE_BUILD 1)
-
-  find_llvm_parts()
-
-  # Add LLVM Functions --------------------------------------------------------
-  if (LLVM_FOUND AND LIBCXXABI_USING_INSTALLED_LLVM)
-    include(LLVMConfig) # For TARGET_TRIPLE
-  else()
-    if (WIN32)
-      set(LLVM_ON_UNIX 0)
-      set(LLVM_ON_WIN32 1)
-    else()
-      set(LLVM_ON_UNIX 1)
-      set(LLVM_ON_WIN32 0)
-    endif()
-  endif()
-  if (LLVM_FOUND)
-    include(AddLLVM OPTIONAL)
-  endif()
-
-  # LLVM Options --------------------------------------------------------------
-  if (NOT DEFINED LLVM_INCLUDE_TESTS)
-    set(LLVM_INCLUDE_TESTS ${LLVM_FOUND})
-  endif()
-  if (NOT DEFINED LLVM_INCLUDE_DOCS)
-    set(LLVM_INCLUDE_DOCS ${LLVM_FOUND})
-  endif()
-  if (NOT DEFINED LLVM_ENABLE_SPHINX)
-    set(LLVM_ENABLE_SPHINX OFF)
-  endif()
-
-  # In a standalone build, we don't have llvm to automatically generate the
-  # llvm-lit script for us.  So we need to provide an explicit directory that
-  # the configurator should write the script into.
-  set(LLVM_LIT_OUTPUT_DIR "${libcxxabi_BINARY_DIR}/bin")
-
-  if (LLVM_INCLUDE_TESTS)
-    # Required LIT Configuration ------------------------------------------------
-    # Define the default arguments to use with 'lit', and an option for the user
-    # to override.
-    set(LLVM_DEFAULT_EXTERNAL_LIT "${LLVM_MAIN_SRC_DIR}/utils/lit/lit.py")
-    set(LIT_ARGS_DEFAULT "-sv --show-xfail --show-unsupported")
-    if (MSVC OR XCODE)
-      set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
-    endif()
-    set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
-  endif()
-
-  # Required doc configuration
-  if (LLVM_ENABLE_SPHINX)
-    find_package(Sphinx REQUIRED)
-  endif()
-
-  if (LLVM_ON_UNIX AND NOT APPLE)
-    set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
-  else()
-    set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
-  endif()
-endmacro(configure_out_of_tree_llvm)
-
-configure_out_of_tree_llvm()