From a4b0f85d491f5331cd9197327c8cd6bdbf2a5a1e Mon Sep 17 00:00:00 2001
From: Alison Felizzi <alison.felizzi@mongodb.com>
Date: Mon, 24 Jan 2022 02:44:54 +0000
Subject: [PATCH] Support linking tests with relative RPATH

This change adds support for linking our test executables with a
relative RPATH to the WiredTiger library, via a new configuration
option 'LINK_TESTS_WITH_RELATIVE_RPATH'. This being supported on
Linux and Darwin platforms.  Generally we expect to execute the
test binaries under the CMake build path and don't intend to
install & distribute our test under other paths. Hence it should
be OK to encode a relative RPATH for our test executables.
---
 test/CMakeLists.txt      | 11 +++++++++++
 test/ctest_helpers.cmake | 23 +++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index ce81f1488..0dd4119f0 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -2,6 +2,17 @@ project(test)
 
 include(ctest_helpers.cmake)
 
+# Generally its appropriate to use this configuration when we expect to execute
+# the test binaries under the CMake build path. This should usually be the case
+# as we don't intend to install & distribute our test binaries.
+config_bool(
+    LINK_TESTS_WITH_RELATIVE_RPATH
+    "Link our WiredTiger test executables with a relative runpath \
+    to the WiredTiger library."
+    DEFAULT OFF
+    DEPENDS "WT_LINUX OR WT_DARWIN"
+)
+
 if(WT_WIN)
     # Compile the windows shim library.
     add_subdirectory(windows)
diff --git a/test/ctest_helpers.cmake b/test/ctest_helpers.cmake
index 23b00f930..0d5860f60 100644
--- a/test/ctest_helpers.cmake
+++ b/test/ctest_helpers.cmake
@@ -77,6 +77,29 @@ function(create_test_executable target)
         target_link_libraries(${target} ${CREATE_TEST_LIBS})
     endif()
 
+    if(LINK_TESTS_WITH_RELATIVE_RPATH)
+        # If enabled, additionally link the final test executable with a
+        # relative runpath to the top-level build directory. This being the
+        # build location of the WiredTiger library.
+        set(origin_linker_variable)
+        if(WT_LINUX)
+            set(origin_linker_variable "\\$ORIGIN")
+        elseif(WT_DARWIN)
+            set(origin_linker_variable "@loader_path")
+        else()
+            # Sanity check. We generally don't expect to enter this path, the
+            # 'LINK_TESTS_WITH_RELATIVE_RPATH' configuration should be bound to only
+            # WT_LINUX and WT_DARWIN platforms.
+            message(FATAL_ERROR "Unable to use 'LINK_TESTS_WITH_RELATIVE_RPATH': Unknown platform")
+        endif()
+        file(RELATIVE_PATH relative_rpath ${test_binary_dir} ${CMAKE_BINARY_DIR})
+        set_target_properties(${target}
+            PROPERTIES
+                BUILD_WITH_INSTALL_RPATH FALSE
+                LINK_FLAGS "-Wl,-rpath,${origin_linker_variable}/${relative_rpath}"
+        )
+    endif()
+
     # If compiling for windows, additionally link in the shim library.
     if(WT_WIN)
         target_include_directories(
-- 
2.17.1