build: remove unnecessary flag to control the linker

The `SWIFT_LINKER_FLAGS` allows the user to specify the linker that they
want for Swift and C/C++ have their own flags which let you control
flags which should permit control of the C/C+ linker.  This removes the
unnecessary logic for controlling the linker.  This simplification
always paves the way for migrating further to CMake 3.15+.

Signed-off-by: Rokhini Prabhu <[email protected]>

Author: compnerd

CMakeLists.txt

@@ -30,7 +30,6 @@ include(CheckLibraryExists)
 include(CheckSymbolExists)
 include(GNUInstallDirs)
 include(SwiftSupport)
-include(DispatchUtilities)
 
 set(SWIFT_LIBDIR "lib" CACHE PATH "Library folder name, defined by swift main buildscript")
 set(INSTALL_LIBDIR "${SWIFT_LIBDIR}" CACHE PATH "Path where the libraries should be installed")
@@ -83,18 +82,6 @@ option(ENABLE_DTRACE "enable dtrace support" "")
 
 option(ENABLE_TESTING "build libdispatch tests" ON)
 
-option(USE_LLD_LINKER "use the lld linker" FALSE)
-
-if(NOT USE_LLD_LINKER AND
-   (CMAKE_SYSTEM_NAME STREQUAL Linux OR
-    CMAKE_SYSTEM_NAME STREQUAL FreeBSD OR
-    CMAKE_SYSTEM_NAME STREQUAL Android))
-  set(USE_GOLD_LINKER_DEFAULT TRUE)
-else()
-  set(USE_GOLD_LINKER_DEFAULT FALSE)
-endif()
-option(USE_GOLD_LINKER "use the gold linker" ${USE_GOLD_LINKER_DEFAULT})
-
 option(ENABLE_THREAD_LOCAL_STORAGE "enable usage of thread local storage via _Thread_local" ON)
 set(DISPATCH_USE_THREAD_LOCAL_STORAGE ${ENABLE_THREAD_LOCAL_STORAGE})
 

cmake/modules/DispatchUtilities.cmake

@@ -116,20 +116,6 @@ if(ENABLE_SWIFT)
                         PROPERTIES
                           POSITION_INDEPENDENT_CODE YES)
 
-  if(USE_LLD_LINKER)
-    if(CMAKE_HOST_SYSTEM_NAME STREQUAL Windows)
-      set(use_ld_flag -use-ld=lld.exe)
-    else()
-      set(use_ld_flag -use-ld=lld)
-    endif()
-  elseif(USE_GOLD_LINKER)
-    if(CMAKE_HOST_SYSTEM_NAME STREQUAL Windows)
-      set(use_ld_flag -use-ld=gold.exe)
-    else()
-      set(use_ld_flag -use-ld=gold)
-    endif()
-  endif()
-
   add_swift_library(swiftDispatch
                     CFLAGS
                       -fblocks
@@ -138,7 +124,6 @@ if(ENABLE_SWIFT)
                       module-maps
                       DispatchStubs
                     LINK_FLAGS
-                      ${use_ld_flag}
                       -lDispatchStubs
                       -L $<TARGET_LINKER_FILE_DIR:BlocksRuntime>
                       -lBlocksRuntime
@@ -260,7 +245,6 @@ if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
                  "-Xlinker -dead_strip"
                  "-Xlinker -alias_list -Xlinker ${PROJECT_SOURCE_DIR}/xcodeconfig/libdispatch.aliases")
 endif()
-dispatch_set_linker(dispatch)
 
 install(TARGETS
           dispatch