[compiler-rt] 7cc5d07 - Revert "[compiler-rt] Check for and use -lunwind when linking with -nodefaultlibs (#65912)"

[Martin Storsjö via llvm-commits]

Author: Martin Storsjö
Date: 2023-09-15T11:55:59+03:00
New Revision: 7cc5d073bd41d061c57013b4d010c4c60ca0775c

URL: https://github.com/llvm/llvm-project/commit/7cc5d073bd41d061c57013b4d010c4c60ca0775c
DIFF: https://github.com/llvm/llvm-project/commit/7cc5d073bd41d061c57013b4d010c4c60ca0775c.diff

LOG: Revert "[compiler-rt] Check for and use -lunwind when linking with -nodefaultlibs (#65912)"

This reverts commit 64c0bddb7639dd4bfad73fbbc909ca739b84aa10.

This seems to run into errors on some buildbots; configure errors
out like this:

    -- Looking for _Unwind_RaiseException in unwind
    -- Looking for _Unwind_RaiseException in unwind - not found
    CMake Error at /usr/share/cmake-3.25/Modules/CheckLibraryExists.cmake:71 (try_compile):
      Only libraries may be used as try_compile or try_run IMPORTED
      LINK_LIBRARIES.  Got unwind of type UTILITY.
    Call Stack (most recent call first):
      /b/sanitizer-aarch64-linux-fuzzer/build/llvm-project/compiler-rt/cmake/config-ix.cmake:66 (check_library_exists)
      /b/sanitizer-aarch64-linux-fuzzer/build/llvm-project/compiler-rt/CMakeLists.txt:281 (include)

Added: 
    

Modified: 
    compiler-rt/cmake/config-ix.cmake

Removed: 
    


################################################################################
diff  --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index 8a5b2792661da9d..09a9b62ce4cd37b 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -63,12 +63,6 @@ if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
                         moldname mingwex msvcrt)
     list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES})
   endif()
-  check_library_exists(unwind _Unwind_RaiseException "" COMPILER_RT_HAS_LIBUNWIND)
-  if (COMPILER_RT_HAS_LIBUNWIND)
-    # If we're omitting default libraries, we might need to manually link in libunwind.
-    # This can affect whether we detect a statically linked libc++ correctly.
-    list(APPEND CMAKE_REQUIRED_LIBRARIES unwind)
-  endif()
 endif ()
 
 # CodeGen options.