Support mold linker (#5331)

cmake/ClangTidy.cmake

@@ -1,3 +1,8 @@
+# Copyright (c) 2020 vesoft inc. All rights reserved.
+#
+# This source code is licensed under Apache 2.0 License.
+#
+
 if (ENABLE_CLANG_TIDY)
     if (${CMAKE_VERSION} VERSION_LESS "3.6.0")
         message(FATAL_ERROR "clang-tidy requires CMake version at least 3.6.")

cmake/FindMoldLinker.cmake

@@ -0,0 +1,18 @@
+# Copyright (c) 2023 vesoft inc. All rights reserved.
+#
+# This source code is licensed under Apache 2.0 License.
+#
+
+find_program (MOLD NAMES "mold")
+if (NOT MOLD)
+  message(FATAL_ERROR "Could not find the mold linker")
+endif()
+
+if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12.1.0)
+  get_filename_component(MOLD_PATH ${MOLD} DIRECTORY)
+  nebula_add_exe_linker_flag(-B${MOLD_PATH}/../libexec/mold)
+  nebula_add_shared_linker_flag(-B${MOLD_PATH}/../libexec/mold)
+else()
+  nebula_add_exe_linker_flag(-fuse-ld=mold)
+  nebula_add_shared_linker_flag(-fuse-ld=mold)
+endif()

cmake/nebula/LinkerConfig.cmake

@@ -1,7 +1,7 @@
 set(NEBULA_USE_LINKER
   "bfd"
   CACHE STRING "Linker to be used")
-set(USER_LINKER_OPTION_VALUES "lld" "gold" "bfd")
+set(USER_LINKER_OPTION_VALUES "lld" "gold" "bfd" "mold")
 set_property(CACHE NEBULA_USE_LINKER PROPERTY STRINGS ${USER_LINKER_OPTION_VALUES})
 list(
   FIND
@@ -17,8 +17,13 @@ endif()
 
 print_config(NEBULA_USE_LINKER)
 
-nebula_add_exe_linker_flag(-fuse-ld=${NEBULA_USE_LINKER})
-nebula_add_shared_linker_flag(-fuse-ld=${NEBULA_USE_LINKER})
+if (${NEBULA_USE_LINKER} STREQUAL "mold")
+  include(FindMoldLinker)
+else()
+  nebula_add_exe_linker_flag(-fuse-ld=${NEBULA_USE_LINKER})
+  nebula_add_shared_linker_flag(-fuse-ld=${NEBULA_USE_LINKER})
+endif()
+
 nebula_add_exe_linker_flag(-static-libstdc++)
 nebula_add_exe_linker_flag(-static-libgcc)
 nebula_add_exe_linker_flag(-no-pie)