llvm12/trunk/add-fno-semantic-interposition.patch

   1 diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
   2 --- a/llvm/cmake/modules/HandleLLVMOptions.cmake
   3 +++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
   4 @@ -305,6 +305,17 @@
   5      # On Windows all code is PIC. MinGW warns if -fPIC is used.
   6    else()
   7      add_flag_or_print_warning("-fPIC" FPIC)
   8 +    # Enable interprocedural optimizations for non-inline functions which would
   9 +    # otherwise be disabled due to GCC -fPIC's default.
  10 +    #
  11 +    # Note: Clang allows IPO for -fPIC so this optimization is less effective.
  12 +    # Older Clang may support -fno-semantic-interposition but it used local
  13 +    # aliases to optimize global variables, which is incompatible with copy
  14 +    # relocations due to -fno-pic.
  15 +    if (CMAKE_COMPILER_IS_GNUCXX OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
  16 +        CMAKE_CXX_COMPILER_VERSION GREATER_EQUAL 13))
  17 +      add_flag_if_supported("-fno-semantic-interposition" FNO_SEMANTIC_INTERPOSITION)
  18 +    endif()
  19    endif()
  20    # GCC for MIPS can miscompile LLVM due to PR37701.
  21    if(CMAKE_COMPILER_IS_GNUCXX AND LLVM_NATIVE_ARCH STREQUAL "Mips" AND
  22