commit 82ee1f5c31a618d3fb167953e0516dce28b52263
Date:   Thu May 7 15:29:46 2020 +0530

    [CMake] fix runpath for ELF platforms
    
    Remove the absolute path to the host toolchain's stdlib from plutil, and add
    it as a CMake BUILD_PATH, so that it's removed upon installation.

diff --git a/swift-corelibs-foundation/Sources/Tools/plutil/CMakeLists.txt b/swift-corelibs-foundation/Sources/Tools/plutil/CMakeLists.txt
index 7f2913b3..3c9163c1 100644
--- a/swift-corelibs-foundation/Sources/Tools/plutil/CMakeLists.txt
+++ b/swift-corelibs-foundation/Sources/Tools/plutil/CMakeLists.txt
@@ -2,6 +2,30 @@ add_executable(plutil
   main.swift)
 target_link_libraries(plutil PRIVATE
   Foundation)
+
+# On ELF platforms, remove the absolute rpath to the host toolchain's stdlib, then add it
+# back temporarily as a BUILD_RPATH just for the tests.
+if(NOT CMAKE_SYSTEM_NAME MATCHES "Darwin|Windows")
+  target_link_options(plutil PRIVATE "SHELL:-no-toolchain-stdlib-rpath")
+
+  # This assumes the host is the target, pass a target flag when cross-compiling.
+  execute_process(
+    COMMAND ${CMAKE_Swift_COMPILER} -print-target-info
+    OUTPUT_VARIABLE output
+    ERROR_VARIABLE error_output
+    RESULT_VARIABLE result
+  )
+  if(NOT ${result} EQUAL 0)
+    message(FATAL_ERROR "Error getting target info with\n"
+      "  `${CMAKE_Swift_COMPILER} -print-target-info`\n"
+      "Error:\n"
+      "  ${error_output}")
+  endif()
+
+  string(REGEX MATCH "\"runtimeLibraryPaths\": \\[\n\ +\"([^\"]+)\"" path ${output})
+  set_target_properties(plutil PROPERTIES BUILD_RPATH ${CMAKE_MATCH_1})
+endif()
+
 set_target_properties(plutil PROPERTIES
   INSTALL_RPATH "$ORIGIN/../lib/swift/$<LOWER_CASE:${CMAKE_SYSTEM_NAME}>")