[libc++abi][ci] Add a from-scratch config for libc++abi on Apple/system

[ldionne]

Summary

I came across an issue where since we build the library for Apple with
the install name directory being /usr/lib, which means that if we don't
run the tests with DYLD_LIBRARY_PATH, we'll end up loading the
system-provided libc++abi when running the tests. That wreaks havoc.

Instead of fixing it in the legacy config file, this commit introduces
an Apple libc++abi config file that does the right thing.

[ldionne]

Rebase onto main

[ldionne]

Repurpose patch

[ldionne]

Fix test failures.

libcxx/utils/ci/apple-install-libcxx.sh

(cd "${build_dir}/${arch}" &&
             -DCMAKE_MAKE_PROGRAM="$(xcrun --sdk "${sdk}" --find ninja)" \
             -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
             -C "${llvm_root}/libcxx/cmake/caches/Apple.cmake" \
             -DCMAKE_INSTALL_PREFIX="${build_dir}/${arch}-install" \
             -DCMAKE_INSTALL_NAME_DIR="/usr/lib" \
             -DCMAKE_OSX_ARCHITECTURES="${arch}" \
             -DLIBCXXABI_LIBRARY_VERSION="${version}" \
             -DLIBCXX_INCLUDE_BENCHMARKS=OFF \
-            -DLIBCXX_TEST_CONFIG="apple-libc++-shared.cfg.in"
+            -DLIBCXX_TEST_CONFIG="apple-libc++-shared.cfg.in" \
+            -DLIBCXXABI_TEST_CONFIG="apple-libc++abi-shared.cfg.in"
     )
 
     xcrun --sdk "${sdk}" cmake --build "${build_dir}/${arch}" --target install-cxx install-cxxabi -- -v
 done
 
 function universal_dylib() {
     dylib=${1}
 

libcxx/utils/ci/run-buildbot

generic-no-wide-characters)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-wide-characters.cmake" \
                    -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in"
     check-runtimes
 ;;
 x86_64-apple-system)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
-                   -DLIBCXX_TEST_CONFIG="apple-libc++-shared.cfg.in"
+                   -DLIBCXX_TEST_CONFIG="apple-libc++-shared.cfg.in" \
+                   -DLIBCXXABI_TEST_CONFIG="apple-libc++abi-shared.cfg.in"
     check-runtimes
 ;;
 x86_64-apple-system-backdeployment-*)
     clean
 
     if [[ "${OSX_ROOTS}" == "" ]]; then
         echo "--- Downloading previous macOS dylibs"
         PREVIOUS_DYLIBS_URL="https://dl.dropboxusercontent.com/s/liu4fmc53qzlfly/libcxx-roots.tar.gz"

libcxxabi/CMakeLists.txt

if (LIBCXXABI_STANDALONE_BUILD)
   endif()
 endif()
 
 option(LIBCXXABI_HERMETIC_STATIC_LIBRARY
   "Do not export any symbols from the static library." OFF)
 
 set(LIBCXXABI_TEST_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/test/lit.site.cfg.in" CACHE STRING
   "The path to the Lit testing configuration to use when running the tests.
-   If a relative path is provided, it is assumed to be relative to '<monorepo>/libcxx/test/configs'.")
+   If a relative path is provided, it is assumed to be relative to '<monorepo>/libcxxabi/test/configs'.")
 if (NOT IS_ABSOLUTE "${LIBCXXABI_TEST_CONFIG}")
-  set(LIBCXXABI_TEST_CONFIG "${LIBCXXABI_LIBCXX_PATH}/test/configs/${LIBCXXABI_TEST_CONFIG}")
+  set(LIBCXXABI_TEST_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/test/configs/${LIBCXXABI_TEST_CONFIG}")
 endif()
 set(LIBCXXABI_TEST_PARAMS "" CACHE STRING
     "A list of parameters to run the Lit test suite with.")
 
 #===============================================================================
 # Configure System
 #===============================================================================
 

libcxxabi/test/CMakeLists.txt

 endif()
 
 foreach(param IN LISTS LIBCXXABI_TEST_PARAMS)
   string(REGEX REPLACE "(.+)=(.+)" "\\1" name "${param}")
   string(REGEX REPLACE "(.+)=(.+)" "\\2" value "${param}")
   serialize_lit_param("${name}" "\"${value}\"")
 endforeach()
 
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/configs/cmake-bridge.cfg.in"
+               "${CMAKE_CURRENT_BINARY_DIR}/cmake-bridge.cfg"
+               @ONLY)
+
 configure_lit_site_cfg(
   "${LIBCXXABI_TEST_CONFIG}"
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
   MAIN_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py")
 
 add_lit_testsuite(check-cxxabi "Running libcxxabi tests"
   ${CMAKE_CURRENT_BINARY_DIR}
   DEPENDS ${LIBCXXABI_TEST_DEPS})

libcxxabi/test/configs/apple-libc++abi-shared.cfg.in

+# Testing configuration for Apple's system libc++abi.
+
+import sys
+
+lit_config.load_config(config, '@CMAKE_CURRENT_BINARY_DIR@/cmake-bridge.cfg')
+
+config.substitutions.append(('%{flags}',
+    '-isysroot {}'.format('@CMAKE_OSX_SYSROOT@') if '@CMAKE_OSX_SYSROOT@' else ''
+))
+config.substitutions.append(('%{compile_flags}',
+    '-nostdinc++ -isystem %{install}/include/c++/v1 -DLIBCXXABI_NO_TIMER -D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS ' +
+    '-I %{libcxx}/test/support -I %{libcxx}/src'
+))
+config.substitutions.append(('%{link_flags}',
+    '-nostdlib++ -L %{install}/lib -lc++ -lc++abi'
+))
+config.substitutions.append(('%{exec}',
+    '{} %{{libcxx}}/utils/run.py --execdir %T --env DYLD_LIBRARY_PATH=%{{install}}/lib -- '.format(sys.executable)
+))
+
+import os, site
+site.addsitedir(os.path.join('@LIBCXXABI_LIBCXX_PATH@', 'utils'))
+import libcxx.test.params, libcxx.test.newconfig, libcxx.test.newconfig
+libcxx.test.newconfig.configure(
+    libcxx.test.params.DEFAULT_PARAMETERS,
+    libcxx.test.features.DEFAULT_FEATURES,
+    config,
+    lit_config
+)

libcxxabi/test/configs/cmake-bridge.cfg.in

+@AUTO_GEN_COMMENT@
+
+@SERIALIZED_LIT_PARAMS@
+
+#
+# This file performs the bridge between the CMake configuration and the Lit
+# configuration files by setting up the LitConfig object and various Lit
+# substitutions from CMake variables.
+#
+# Individual configuration files can take advantage of this bridge by
+# loading the file and then setting up the remaining Lit substitutions.
+#
+
+import os, site
+site.addsitedir(os.path.join('@LIBCXXABI_LIBCXX_PATH@', 'utils'))
+site.addsitedir(os.path.join('@LIBCXXABI_SOURCE_DIR@', 'test'))
+import libcxx.test.format
+
+# Basic configuration of the test suite
+config.name = os.path.basename('@LIBCXXABI_TEST_CONFIG@')
+config.test_source_root = os.path.join('@LIBCXXABI_SOURCE_DIR@', 'test')
+config.test_format = libcxx.test.format.CxxStandardLibraryTest()
+config.recursiveExpansionLimit = 10
+config.test_exec_root = '@CMAKE_BINARY_DIR@'
+
+# TODO: This is a non-standard Lit attribute and we should have another way of accessing this.
+config.host_triple = '@LLVM_HOST_TRIPLE@'
+
+config.substitutions.append(('%{cxx}', '@CMAKE_CXX_COMPILER@'))
+config.substitutions.append(('%{libcxx}', '@LIBCXXABI_LIBCXX_PATH@'))
+config.substitutions.append(('%{install}', '@CMAKE_BINARY_DIR@'))