[libunwind] Make sure libunwind test dependencies are installed before running tests

[ldionne]

This patch adds an installation step where we install libc++ in a fake installation tree before testing libunwind. This is necessary because some configurations (in particular "generic-merged") require libc++ to be installed, since the libunwind tests are actually linking libc++.so in which libc++abi.a and libunwind.a have been merged.

Without this, we were actually failing to find libc++.so to link against and then linking against whatever system library we'd find in the provided search directories. While this happens to work in the current CI configuration, this breaks down when updating to newer build tools.

[llvmbot]

@llvm/pr-subscribers-libunwind

Author: Louis Dionne (ldionne)

Changes

This patch adds an installation step where we install libc++ in a fake installation tree before testing libunwind. This is necessary because some configurations (in particular "generic-merged") require libc++ to be installed, since the libunwind tests are actually linking libc++.so in which libc++abi.a and libunwind.a have been merged.

---

Full diff: https://github.com/llvm/llvm-project/pull/171474.diff

2 Files Affected:

• (modified) libunwind/CMakeLists.txt (+3)
• (modified) libunwind/test/CMakeLists.txt (+22-1)

diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
index 97edff0b87ea3..fbef71f3f7446 100644
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -336,6 +336,9 @@ if (RUNTIMES_EXECUTE_ONLY_CODE)
   add_compile_definitions(_LIBUNWIND_EXECUTE_ONLY_CODE)
 endif()
 
+add_custom_target(unwind-test-depends
+  COMMENT "Build dependencies required to run the libunwind test suite.")
+
 #===============================================================================
 # Setup Source Code
 #===============================================================================
diff --git a/libunwind/test/CMakeLists.txt b/libunwind/test/CMakeLists.txt
index c222c0bdbf5af..815bc86692860 100644
--- a/libunwind/test/CMakeLists.txt
+++ b/libunwind/test/CMakeLists.txt
@@ -9,6 +9,26 @@ macro(pythonize_bool var)
 endmacro()
 
 set(LIBUNWIND_TESTING_INSTALL_PREFIX "${LIBUNWIND_BINARY_DIR}/test-suite-install")
+add_custom_target(libunwind-install-cxx-for-testing
+                    DEPENDS cxx-headers
+                            cxx
+                            cxx_experimental
+                            cxx-modules
+                    COMMAND ${CMAKE_COMMAND} -E make_directory "${LIBUNWIND_TESTING_INSTALL_PREFIX}"
+                    COMMAND "${CMAKE_COMMAND}"
+                            -DCMAKE_INSTALL_COMPONENT=cxx-headers
+                            -DCMAKE_INSTALL_PREFIX="${LIBUNWIND_TESTING_INSTALL_PREFIX}"
+                            -P "${CMAKE_BINARY_DIR}/cmake_install.cmake"
+                    COMMAND "${CMAKE_COMMAND}"
+                            -DCMAKE_INSTALL_COMPONENT=cxx-modules
+                            -DCMAKE_INSTALL_PREFIX="${LIBUNWIND_TESTING_INSTALL_PREFIX}"
+                            -P "${CMAKE_BINARY_DIR}/cmake_install.cmake"
+                    COMMAND "${CMAKE_COMMAND}"
+                            -DCMAKE_INSTALL_COMPONENT=cxx
+                            -DCMAKE_INSTALL_PREFIX="${LIBUNWIND_TESTING_INSTALL_PREFIX}"
+                            -P "${CMAKE_BINARY_DIR}/cmake_install.cmake")
+add_dependencies(unwind-test-depends libunwind-install-cxx-for-testing)
+
 add_custom_target(libunwind-install-unwind-for-testing
   DEPENDS unwind-headers
           unwind
@@ -21,6 +41,7 @@ add_custom_target(libunwind-install-unwind-for-testing
           -DCMAKE_INSTALL_COMPONENT=unwind
           -DCMAKE_INSTALL_PREFIX="${LIBUNWIND_TESTING_INSTALL_PREFIX}"
           -P "${CMAKE_BINARY_DIR}/cmake_install.cmake")
+add_dependencies(unwind-test-depends libunwind-install-unwind-for-testing)
 
 pythonize_bool(LIBUNWIND_ENABLE_CET)
 pythonize_bool(LIBUNWIND_ENABLE_GCS)
@@ -62,4 +83,4 @@ configure_lit_site_cfg(
 
 add_lit_testsuite(check-unwind "Running libunwind tests"
   ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS libunwind-install-unwind-for-testing)
+  DEPENDS unwind-test-depends)