[compiler-rt] Add custom libc++ workaround for CMake < 3.26

[arichardson]

The INSTALL_BYPRODUCTS ExternalProject_Add() argument was only added in
CMake 3.26 and the current minimum is 3.20. Work around this by using an
explicit ExternalProject_Add_Step() call for the install step with a
BYPRODUCTS argument. We can't keep using the install name here since that
is reserved by the CMake implementation and results in errors when used.

This commit should be reverted once LLVM depends on CMake 3.26.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Alexander Richardson (arichardson)

Changes

The INSTALL_BYPRODUCTS ExternalProject_Add() argument was only added in
CMake 3.26 and the current minimum is 3.20. Work around this by using an
explicit ExternalProject_Add_Step() call for the install step with a
BYPRODUCTS argument. We can't keep using the install name here since that
is reserved by the CMake implementation and results in errors when used.

This commit should be reverted once LLVM depends on CMake 3.26.

---

Full diff: https://github.com/llvm/llvm-project/pull/115677.diff

5 Files Affected:

• (modified) compiler-rt/cmake/Modules/AddCompilerRT.cmake (+16-4)
• (modified) compiler-rt/lib/fuzzer/CMakeLists.txt (+3-3)
• (modified) compiler-rt/lib/fuzzer/tests/CMakeLists.txt (+1-1)
• (modified) compiler-rt/lib/msan/tests/CMakeLists.txt (+3-3)
• (modified) compiler-rt/lib/tsan/CMakeLists.txt (+1-1)

diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
index 4873bec39f8afc..77261f631ea117 100644
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -706,18 +706,30 @@ macro(add_custom_libcxx name prefix)
                -DLLVM_INCLUDE_TESTS=OFF
                -DLLVM_INCLUDE_DOCS=OFF
                ${LIBCXX_CMAKE_ARGS}
-    STEP_TARGETS configure build install
+    STEP_TARGETS configure build
     BUILD_ALWAYS 1
     USES_TERMINAL_CONFIGURE 1
     USES_TERMINAL_BUILD 1
     USES_TERMINAL_INSTALL 1
     LIST_SEPARATOR |
     EXCLUDE_FROM_ALL TRUE
+    )
+
+  # Once we depend on CMake 3.26, we can use the INSTALL_BYPRODUCTS argument
+  # instead of having to fall back to ExternalProject_Add_Step()
+  # Note: We can't use the normal name "install" here since that interferes
+  # with the default ExternalProject_Add() logic and causes errors.
+  ExternalProject_Add_Step(${name} install-cmake326-workaround
     # Ensure that DESTDIR=... set in the out environment does not affect this
     # target (we always need to install to the build directory).
-    INSTALL_COMMAND env DESTDIR= ${CMAKE_COMMAND} --build ${prefix}/build --target install
-    INSTALL_BYPRODUCTS "${prefix}/lib/libc++.a" "${prefix}/lib/libc++abi.a"
-    )
+    COMMAND env DESTDIR= ${CMAKE_COMMAND} --build ${prefix}/build --target install
+    COMMENT "Installing ${name}..."
+    BYPRODUCTS "${prefix}/lib/libc++.a" "${prefix}/lib/libc++abi.a"
+    DEPENDEES build
+    EXCLUDE_FROM_MAIN 1
+    USES_TERMINAL 1
+  )
+  ExternalProject_Add_StepTargets(${name} install-cmake326-workaround)
 
   if (CMAKE_GENERATOR MATCHES "Make")
     set(run_clean "$(MAKE)" "-C" "${prefix}" "clean")
diff --git a/compiler-rt/lib/fuzzer/CMakeLists.txt b/compiler-rt/lib/fuzzer/CMakeLists.txt
index a6175564e55a20..6db24610df1f06 100644
--- a/compiler-rt/lib/fuzzer/CMakeLists.txt
+++ b/compiler-rt/lib/fuzzer/CMakeLists.txt
@@ -166,11 +166,11 @@ if(OS_NAME MATCHES "Android|Linux|Fuchsia" AND
                  -DLIBCXX_ABI_NAMESPACE=__Fuzzer
                  -DLIBCXX_ENABLE_EXCEPTIONS=OFF)
     target_compile_options(RTfuzzer.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
-    add_dependencies(RTfuzzer.${arch} libcxx_fuzzer_${arch}-install)
+    add_dependencies(RTfuzzer.${arch} libcxx_fuzzer_${arch}-install-cmake326-workaround)
     target_compile_options(RTfuzzer_main.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
-    add_dependencies(RTfuzzer_main.${arch} libcxx_fuzzer_${arch}-install)
+    add_dependencies(RTfuzzer_main.${arch} libcxx_fuzzer_${arch}-install-cmake326-workaround)
     target_compile_options(RTfuzzer_interceptors.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
-    add_dependencies(RTfuzzer_interceptors.${arch} libcxx_fuzzer_${arch}-install)
+    add_dependencies(RTfuzzer_interceptors.${arch} libcxx_fuzzer_${arch}-install-cmake326-workaround)
     partially_link_libcxx(fuzzer_no_main ${LIBCXX_${arch}_PREFIX} ${arch})
     partially_link_libcxx(fuzzer_interceptors ${LIBCXX_${arch}_PREFIX} ${arch})
     partially_link_libcxx(fuzzer ${LIBCXX_${arch}_PREFIX} ${arch})
diff --git a/compiler-rt/lib/fuzzer/tests/CMakeLists.txt b/compiler-rt/lib/fuzzer/tests/CMakeLists.txt
index 73ebc135312090..adfae3d63e648a 100644
--- a/compiler-rt/lib/fuzzer/tests/CMakeLists.txt
+++ b/compiler-rt/lib/fuzzer/tests/CMakeLists.txt
@@ -64,7 +64,7 @@ if(COMPILER_RT_DEFAULT_TARGET_ARCH IN_LIST FUZZER_SUPPORTED_ARCH)
      COMPILER_RT_LIBCXX_PATH AND
      COMPILER_RT_LIBCXXABI_PATH)
     file(GLOB libfuzzer_headers ../*.h)
-    set(LIBFUZZER_TEST_RUNTIME_DEPS libcxx_fuzzer_${arch}-install ${libfuzzer_headers})
+    set(LIBFUZZER_TEST_RUNTIME_DEPS libcxx_fuzzer_${arch}-install-cmake326-workaround ${libfuzzer_headers})
     set(LIBFUZZER_TEST_RUNTIME_CFLAGS -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
     set(LIBFUZZER_TEST_RUNTIME_LINK_FLAGS ${LIBCXX_${arch}_PREFIX}/lib/libc++.a)
   endif()
diff --git a/compiler-rt/lib/msan/tests/CMakeLists.txt b/compiler-rt/lib/msan/tests/CMakeLists.txt
index 3ddae6d08b7f67..a8500225337e62 100644
--- a/compiler-rt/lib/msan/tests/CMakeLists.txt
+++ b/compiler-rt/lib/msan/tests/CMakeLists.txt
@@ -69,7 +69,7 @@ macro(msan_compile obj_list source arch kind cflags)
   sanitizer_test_compile(
     ${obj_list} ${source} ${arch}
     KIND ${kind}
-    COMPILE_DEPS ${MSAN_UNITTEST_HEADERS} libcxx_msan_${arch}-install
+    COMPILE_DEPS ${MSAN_UNITTEST_HEADERS} libcxx_msan_${arch}-install-cmake326-workaround
     DEPS msan
     CFLAGS -isystem ${MSAN_LIBCXX_DIR}/../include/c++/v1
            ${MSAN_UNITTEST_INSTRUMENTED_CFLAGS} ${cflags}
@@ -117,10 +117,10 @@ macro(add_msan_tests_for_arch arch kind cflags)
                    DEPS ${MSAN_INST_LOADABLE_OBJECTS})
 
   set(MSAN_TEST_OBJECTS ${MSAN_INST_TEST_OBJECTS} ${MSAN_INST_GTEST})
-  set(MSAN_TEST_DEPS ${MSAN_TEST_OBJECTS} libcxx_msan_${arch}-install
+  set(MSAN_TEST_DEPS ${MSAN_TEST_OBJECTS} libcxx_msan_${arch}-install-cmake326-workaround
                      ${MSAN_LOADABLE_SO}
                      "${MSAN_LIBCXX_DIR}/libc++.a" "${MSAN_LIBCXX_DIR}/libc++abi.a")
-  list(APPEND MSAN_TEST_DEPS msan libcxx_msan_${arch}-install)
+  list(APPEND MSAN_TEST_DEPS msan libcxx_msan_${arch}-install-cmake326-workaround)
   get_target_flags_for_arch(${arch} TARGET_LINK_FLAGS)
   add_compiler_rt_test(MsanUnitTests "Msan-${arch}${kind}-Test" ${arch}
     OBJECTS ${MSAN_TEST_OBJECTS} "${MSAN_LIBCXX_DIR}/libc++.a" "${MSAN_LIBCXX_DIR}/libc++abi.a"
diff --git a/compiler-rt/lib/tsan/CMakeLists.txt b/compiler-rt/lib/tsan/CMakeLists.txt
index f7e2b5b6a35631..7928116879c09e 100644
--- a/compiler-rt/lib/tsan/CMakeLists.txt
+++ b/compiler-rt/lib/tsan/CMakeLists.txt
@@ -31,7 +31,7 @@ if(COMPILER_RT_LIBCXX_PATH AND
       DEPS ${TSAN_RUNTIME_LIBRARIES}
       CFLAGS ${TARGET_CFLAGS} -fsanitize=thread
       USE_TOOLCHAIN)
-    list(APPEND libcxx_tsan_deps libcxx_tsan_${arch}-install)
+    list(APPEND libcxx_tsan_deps libcxx_tsan_${arch}-install-cmake326-workaround)
   endforeach()
 
   add_custom_target(libcxx_tsan DEPENDS ${libcxx_tsan_deps})

[arichardson]

Will land this once CI completes.