[llvm] r220237 - Explain why we don't always use --gc-sections.

[Rafael Espindola]

Author: rafael
Date: Mon Oct 20 16:37:38 2014
New Revision: 220237

URL: http://llvm.org/viewvc/llvm-project?rev=220237&view=rev
Log:
Explain why we don't always use --gc-sections.

Modified:
    llvm/trunk/cmake/modules/AddLLVM.cmake

Modified: llvm/trunk/cmake/modules/AddLLVM.cmake
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/cmake/modules/AddLLVM.cmake?rev=220237&r1=220236&r2=220237&view=diff
==============================================================================
--- llvm/trunk/cmake/modules/AddLLVM.cmake (original)
+++ llvm/trunk/cmake/modules/AddLLVM.cmake Mon Oct 20 16:37:38 2014
@@ -143,10 +143,14 @@ endfunction(add_llvm_symbol_exports)
 function(add_dead_strip target_name)
   if(NOT LLVM_NO_DEAD_STRIP)
     if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+      # ld64's implementation of -dead_strip breaks tools that use plugins.
       set_property(TARGET ${target_name} APPEND_STRING PROPERTY
                    LINK_FLAGS " -Wl,-dead_strip")
     elseif(NOT WIN32)
       # Object files are compiled with -ffunction-data-sections.
+      # Versions of bfd ld < 2.23.1 have a bug in --gc-sections that breaks
+      # tools that use plugins. Always pass --gc-sections once we require
+      # a newer linker.
       set_property(TARGET ${target_name} APPEND_STRING PROPERTY
                    LINK_FLAGS " -Wl,--gc-sections")
     endif()