[libcxx] Add Testing Configuration for LLVM libc

This patch adds a CMake cache, and the testing configs to build libc++
and run the tests against LLVM libc.

Reviewers: ldionne, philnik777, jtstogel

Pull Request: https://github.com/llvm/llvm-project/pull/165120

libcxx/cmake/caches/Generic-llvm-libc.cmake

@@ -0,0 +1,62 @@
+set(LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
+set(LIBUNWIND_INSTALL_LIBRARY ON CACHE BOOL "")
+set(LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
+
+set(LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
+set(COMPILER_RT_CXX_LIBRARY "libcxx" CACHE STRING "")
+
+set(COMPILER_RT_USE_LLVM_UNWINDER OFF CACHE BOOL "")
+set(COMPILER_RT_BUILD_BUILTINS ON CACHE BOOL "")
+set(COMPILER_RT_BUILD_CRT ON CACHE BOOL "")
+set(COMPILER_RT_BUILD_STANDALONE_LIBATOMIC OFF CACHE BOOL "")
+set(COMPILER_RT_HAS_FNO_BUILTIN_FLAG ON CACHE BOOL "")
+set(COMPILER_RT_BUILTINS_HIDE_SYMBOLS ON CACHE BOOL "")
+set(COMPILER_RT_HAS_VISIBILITY_HIDDEN_FLAG ON CACHE BOOL "")
+set(COMPILER_RT_BUILD_MEMPROF OFF CACHE BOOL "")
+set(COMPILER_RT_BUILD_PROFILE OFF CACHE BOOL "")
+set(COMPILER_RT_BUILD_SANITIZERS ON CACHE BOOL "")
+set(COMPILER_RT_BUILD_XRAY OFF CACHE BOOL "")
+set(COMPILER_RT_BUILD_ORC OFF CACHE BOOL "")
+set(COMPILER_RT_BUILD_LIBFUZZER OFF CACHE BOOL "")
+set(COMPILER_RT_DEBUG OFF CACHE BOOL "")
+set(COMPILER_RT_CRT_USE_EH_FRAME_REGISTRY ON CACHE BOOL "")
+
+set(LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
+set(LIBCXXABI_USE_LLVM_UNWINDER OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
+set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
+set(LIBCXX_INCLUDE_BENCHMARKS OFF CACHE BOOL "")
+
+set(LIBCXX_ENABLE_STATIC ON CACHE BOOL "")
+set(LIBCXX_INSTALL_LIBRARY ON CACHE BOOL "")
+set(LIBCXX_CXX_ABI libcxxabi CACHE STRING "")
+
+# Not yet fully implemented.
+set(LIBCXX_ENABLE_LOCALIZATION OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_WIDE_CHARACTERS OFF CACHE BOOL "")
+
+# Still missing some components.
+set(LIBCXX_ENABLE_FILESYSTEM OFF CACHE BOOL "")
+
+# Still needs validation before turning on.
+set(LIBCXX_ENABLE_RANDOM_DEVICE OFF CACHE BOOL "")
+
+# Still missing some components.
+set(LIBCXX_ENABLE_MONOTONIC_CLOCK OFF CACHE BOOL "")
+
+# requires LIBCXX_ENABLE_MONOTONIC_CLOCK=ON
+set(LIBCXX_ENABLE_THREADS OFF CACHE BOOL "")
+set(LIBCXXABI_ENABLE_THREADS OFF CACHE BOOL "")
+
+set(LIBCXX_ENABLE_UNICODE ON CACHE BOOL "")
+set(LIBCXX_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
+set(LIBCXXABI_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
+set(LIBCXX_ENABLE_RTTI OFF CACHE BOOL "")
+set(RUNTIMES_USE_LIBC "llvm-libc" CACHE STRING "")
+
+set(CMAKE_BUILD_TYPE "Release" CACHE STRING "")
+set(LLVM_ENABLE_RUNTIMES "compiler-rt;libc;libunwind;libcxxabi;libcxx" CACHE STRING "")
+set(LLVM_LIBC_FULL_BUILD ON CACHE BOOL "")
+set(LLVM_LIBC_INCLUDE_SCUDO ON CACHE BOOL "")
+set(COMPILER_RT_BUILD_GWP_ASAN OFF CACHE BOOL "")
+set(COMPILER_RT_BUILD_SCUDO_STANDALONE_WITH_LLVM_LIBC ON CACHE BOOL "")

libcxx/test/configs/llvm-libc++-llvm-libc.cfg.in

@@ -0,0 +1,27 @@
+# This testing configuration handles running the test suite against LLVM's libc++
+# using a static library.
+
+lit_config.load_config(config, '@CMAKE_CURRENT_BINARY_DIR@/cmake-bridge.cfg')
+
+config.substitutions.append(('%{flags}',
+    '-pthread' + (' -isysroot {}'.format('@CMAKE_OSX_SYSROOT@') if '@CMAKE_OSX_SYSROOT@' else '')
+))
+config.substitutions.append(('%{compile_flags}',
+    '-nostdlibinc -I %{include-dir} -I %{target-include-dir} -I @CMAKE_BINARY_DIR@/libc/include -I %{libcxx-dir}/test/support -idirafter @LIBC_KERNEL_HEADERS@'
+))
+config.substitutions.append(('%{link_flags}',
+    '-nodefaultlibs -nostartfiles -L %{lib-dir} -lc++ -lc++abi @CMAKE_BINARY_DIR@/libc/startup/linux/crt1.o @CMAKE_BINARY_DIR@/libc/lib/libc.a @CMAKE_BINARY_DIR@/libc/lib/libm.a -static -fno-use-cxa-atexit @CMAKE_BINARY_DIR@/compiler-rt/lib/linux/libclang_rt.builtins-x86_64.a'
+))
+config.substitutions.append(('%{exec}',
+    '%{executor} --execdir %{temp} -- '
+))
+
+import os, site
+site.addsitedir(os.path.join('@LIBCXX_SOURCE_DIR@', 'utils'))
+import libcxx.test.params, libcxx.test.config
+libcxx.test.config.configure(
+    libcxx.test.params.DEFAULT_PARAMETERS,
+    libcxx.test.features.DEFAULT_FEATURES,
+    config,
+    lit_config
+)

libcxx/utils/ci/run-buildbot

@@ -448,6 +448,26 @@ generic-hardening-mode-debug)
     check-runtimes
     check-abi-list
 ;;
+generic-llvm-libc)
+    clean
+
+    # Install kernel headers from a known-good Linux kernel version to ensure
+    # the test is hermetic.
+    export LINUX_VERSION=7.0.1
+    mkdir -p "${BUILD_DIR}"
+    curl -L "https://cdn.kernel.org/pub/linux/kernel/v7.x/linux-${LINUX_VERSION}.tar.xz" --output "${BUILD_DIR}/linux.tar.xz"
+    tar -xf "${BUILD_DIR}/linux.tar.xz" -C "${BUILD_DIR}"
+    make LLVM=1 INSTALL_HDR_PATH="${BUILD_DIR}/linux-install" -C "${BUILD_DIR}/linux-${LINUX_VERSION}" headers_install
+
+    generate-cmake-base -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-llvm-libc.cmake" \
+                        -DLIBCXX_TEST_CONFIG="llvm-libc++-llvm-libc.cfg.in" \
+                        -DLIBCXXABI_TEST_CONFIG="llvm-libc++abi-llvm-libc.cfg.in" \
+                        -DLIBC_KERNEL_HEADERS="${BUILD_DIR}/linux-install/include"
+    # Ensure we have the builtins archive built as we pass it in explicitly in
+    # the test config.
+    ninja -vC "${BUILD_DIR}" libclang_rt.builtins-x86_64.a
+    check-runtimes
+;;
 #
 # Module builds
 #

libcxxabi/test/configs/llvm-libc++abi-llvm-libc.cfg.in

@@ -0,0 +1,27 @@
+# This testing configuration handles running the test suite against LLVM's libc++abi
+# using a static library.
+
+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++ -I %{include} -I %{cxx-include} -I %{cxx-target-include} %{maybe-include-libunwind} -I %{libcxx}/test/support -I %{libcxx}/src -D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS'
+))
+config.substitutions.append(('%{link_flags}',
+    '-nodefaultlibs -nostartfiles -L %{lib} -lc++ -lc++abi -pthread @CMAKE_BINARY_DIR@/libc/startup/linux/crt1.o @CMAKE_BINARY_DIR@/libc/lib/libc.a -static -fno-use-cxa-atexit'
+))
+config.substitutions.append(('%{exec}',
+    '%{executor} --execdir %{temp} -- '
+))
+
+import os, site
+site.addsitedir(os.path.join('@LIBCXXABI_LIBCXX_PATH@', 'utils'))
+import libcxx.test.params, libcxx.test.config
+libcxx.test.config.configure(
+    libcxx.test.params.DEFAULT_PARAMETERS,
+    libcxx.test.features.DEFAULT_FEATURES,
+    config,
+    lit_config
+)