[llvm] [CMake] Check objcopy support for LLVM_SPLIT_DWARF (PR #80500)

[Jinsong Ji via llvm-commits]

https://github.com/jsji created https://github.com/llvm/llvm-project/pull/80500

LLVM_SPLIT_DWARF require new binutils support for objcopy etc.
This is to check the option and error out if binutils is too old.

Still allow use to override the check if they don't need to use objcopy.


>From 0c2c2dcc9fda039545c5c22a4be8939590996957 Mon Sep 17 00:00:00 2001
From: Jinsong Ji <jinsong.ji at intel.com>
Date: Fri, 2 Feb 2024 13:32:22 -0800
Subject: [PATCH] [CMake] Check objcopy support for LLVM_SPLIT_DWARF

LLVM_SPLIT_DWARF require new binutils support for objcopy etc.
This is to check the option and error out if binutils is too old.

Still allow use to override the check if they don't need to use objcopy.
---
 llvm/cmake/modules/HandleLLVMOptions.cmake | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 0699a8586fcc7..42985a6b2ebba 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -1050,6 +1050,15 @@ if (LLVM_USE_SPLIT_DWARF AND
     llvm_check_linker_flag(CXX "-Wl,--gdb-index" LINKER_SUPPORTS_GDB_INDEX)
     append_if(LINKER_SUPPORTS_GDB_INDEX "-Wl,--gdb-index"
       CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
+    #Test binutils support, error out if it is too old
+    if(${CMAKE_SYSTEM_NAME} MATCHES "Linux" AND NOT LLVM_SPLIT_DWARF_SKIP_OBJCOPY_CHECK)
+       execute_process(COMMAND objcopy --help OUTPUT_VARIABLE helpmsg ERROR_VARIABLE helpmsg)
+       if(NOT helpmsg MATCHES "--extract-dwo")
+          message(FATAL_ERROR "LLVM_USE_SPLIT_DWARF: objcopy does not supports --extract-dwo.\n"
+                              "Upgrade binutils to 2.23+ or reconfigure with -DLLVM_USE_SPLIT_DWARF=OFF.\n"
+                               "-DLLVM_SPLIT_DWARF_SKIP_OBJCOPY_CHECK=TRUE to ignore objcopy check.\n")
+       endif()
+    endif()
   endif()
 endif()